Hi Tom,
Thanks for your interest in the SC7180 TF-A port! You're asking fair
questions about a difficult situation, so let me try to add some
background:
The binary component policy was actually written specifically as part
of the discussions about adding the SC7180 port, to lay some
guidelines and ground rules about how to deal with binary components
(which already existed in some other platform ports beforehand). This
case was discussed in-depth with the project leaders and the
trustedfirmware.org Board beforehand, and it was always understood
that this would have to be a tricky compromise. As you may know,
devices (e.g. Android phones) with Qualcomm chipsets generally do not
run TF-A, but instead run Qualcomm's proprietary trusted OS and secure
monitor (QTEE). The TF-A port was more of an experimental side project
(which has by now resulted in a few SC7180-based Chromebooks being
sold with TF-A, but the much larger phone market continues to use
QTEE), so unfortunately the TF project's position to make demands is
not yet as solid as you may think. Basically, we could have either
made these compromises or continue to not support Qualcomm chipsets at
all, so due to their prevalence in the ecosystem we decided it would
be worth it to start like this, try to make the situation as good as
it can get, and then hopefully improve on that in future chipset
generations.
The binary policy is meant as more of a decision guideline and
individual cases are ultimately up to the Board. FWIW maybe I slightly
mis-summarized the policy in the text added to the contributing.rst
document -- I think saying that the *majority* of the platform port
(in terms of bytes of code) should be open source, while a good
ambition in general, was never realistic for SC7180. The full document
in https://git.trustedfirmware.org/tf-binaries.git/tree/readme.rst
instead says "Binary components that contain all meaningful
functionality of a platform port" are not accepted -- the intention is
that there are pieces large enough to be worth modifying in the open
source part, while allowing vendors to keep functionality proprietary
that they absolutely do not want (or are not allowed) to disclose. For
SC7180, things like UART, SPMI, PMIC and RNG drivers as well as SMC
validation are implemented in open source (and as you noticed some of
those were ported piecemeal at later points of the development
process). I'll be the first to admit that this isn't a lot and we
absolutely want to do more, but it is a tricky and very time-consuming
process both in identifying the exact parts that can be open-sourced
without IP concerns and then actually doing the work (since the
qtiseclib code is still proprietary even if there is a Linux driver
for the same subsystem, we can't just copy things over, it has to be
carefully rewritten and revalidated). The state you see the SC7180
port in right now is basically just as far as we got over the course
of this project (and believe me it took a lot of effort already, even
if it may not look like much). Hopefully we can make further progress
with the next chipset.
Also, just as a note, we didn't actually end up hosting qtiseclib in
the TF binary repository in the end, due to concerns about details in
the license text that couldn't be resolved. It is instead hosted by
the coreboot.org project at the moment. I'm not sure if this
technically means that the TF binary component policy applies to this
blob or not (from a strict reading of the text I would say it
doesn't), but that's not really that relevant... like I said, in the
end the Board makes final decisions about whether a platform port is
accepted into the repository or not on a case by case basis, and the
policy is just a general guideline. The general goal is to make sure
the TF-A ports are actually useful to open source developers while
allowing for pragmatic compromises in tricky situations like this, and
in this case we decided that allowing this port would be more useful
than not (although it's certainly on the edge).
On Tue, Jul 20, 2021 at 2:05 AM Tom Johnsen <tomjohnsen(a)protonmail.com> wrote:
>
> Hello!
>
> I recently discovered the TF-A port for QTI SC7180 and was very happy
> to see this. I always thought it would have been great if Qualcomm made
> (open-source) TF-A ports for their platforms. For example, I would be
> interested in TF-A for the DragonBoard 820c (APQ8096E).
> Unfortunately, after talking to some other people I have been told
> it is unlikely that Qualcomm will ever have this. :-/
>
> I am not much of a firmware developer but I was curious so I wanted to
> check how much SoC-specific code is actually needed for a TF-A port. At
> first I was surprised - the QTI platform ports seem fairly simple, there
> is not much SoC-specific code at all. However, it looks like the reason for
> that is that almost all of the SoC-specific code is actually contained in a
> proprietary "qtiseclib" blob that is statically linked into the bl31.bin.
>
> I did not really expect to see something like that in a public
> open-source project, especially not one as security-critical as TF-A.
> It looks like some binary components are indeed allowed as per the
> Contribution Guidelines (1). Yet, after reading them and looking at the
> code again I wonder how the amount of functionality implemented
> in the "qtiseclib" could really conform to these guidelines?
>
> I quote them here (from (1)) for convenience:
>
> > Binary components must be restricted to only the specific
> > functionality that cannot be open-sourced and must be linked into a
> > larger open-source platform port. The majority of the platform port
> > must still be implemented in open source. Platform ports that are
> > merely a thin wrapper around a binary component that contains all the
> > actual code will not be accepted.
>
> There are two main reasons why I do not think that the "qtiseclib"
> conforms to these guidelines.
>
> --- 1. "Majority of the platform port must be open-source" ---
>
> I have built TF-A for QTI SC7180 according to the documentation (2).
> The resulting bl31.bin has a size of 182088 bytes. The linker conveniently
> produces a "bl31.map" file that shows exactly which part of the binary
> comes from which component of the TF-A port. It can be analyzed easily,
> for example with fpv-gcc (3).
>
> The following table shows the distribution of the bl31.bin:
>
> +-------------+----------+-----+
> | Component | Size (B) | % |
> +-------------+----------+-----+
> | libqtisec.a | 147344 | 81% |
> | Other BL31 | 23838 | 13% |
> | plat/qti | 5222 | 3% |
> | Padding | 3863 | 2% |
> | libc.a | 1821 | 1% |
> +-------------+----------+-----+
>
> Clearly, the libqtisec.a dominates with 81%. The open-source part of the
> QTI TF-A platform port (plat/qti) is merely 3% of the final binary.
>
> Perhaps it is just large static data tables? The following table shows
> only the distribution of .text symbols (excluding libc and "Other BL31"):
>
> +-------------+----------+-----+
> | Component | Size (B) | % |
> +-------------+----------+-----+
> | libqtisec.a | 75792 | 95% |
> | plat/qti | 3920 | 5% |
> +-------------+----------+-----+
>
> I do not see any way to interpret this as "the majority of the platform
> port is open-source". It is hard to find any substantial functionality
> that does not end up calling into the proprietary qtiseclib. In my
> opinion, the port is hardly more than "a thin wrapper around a binary
> component" which is explicitly forbidden in the guidelines.
>
> --- 2. "Binary components should be as minimal as possible" ---
>
> It is hard to judge this given that the license for "qtiseclib" (obviously)
> does not allow reverse-engineering. However, just judging from some of the
> symbol names that I see visibly in the "bl31.map" Qualcomm seems to have
> spent little effort to keep the binary component actually minimal.
>
> "qtiseclib" also contains code for IP blocks that have public
> open-source drivers in Linux, including for:
>
> - TLMM (GPIO)
> - GCC (Clocks)
> - rpmh
>
> Perhaps some "secret" registers are programmed there but it is hard to
> believe that there is no overlap that could have been made open-source.
>
> This is also quite visible based on changes that were made later.
> The PRNG and SPMI driver were moved out of "qtiseclib" later (4, 5)
> and both can be found similarly in Linux.
>
> --- Conclusion ---
>
> How does this conform to the Binary Components policy that is part of
> the contribution guidelines? Was this not checked during review?
>
> All in all I cannot help but get the feeling that Qualcomm has fairly
> little interest to have open-source firmware. Not even simple hardware
> initialization that probably exists similarly in open-source drivers
> has been implemented in open-source code. The resulting bl31.bin can
> be hardly called "open-source" when 81% of it is actually proprietary.
>
> If this is intended and considered acceptable I suggest rewriting the
> "Binary Components" policy to explicitly allow vendors to require
> any amount of proprietary code for their TF-A ports. Personally, I think
> this is a very bad idea though and just encourages all other vendors to
> do the same in the future. TF-A (as a trusted reference implementation)
> is in a good position to make certain demands that must be met for
> inclusion in the upstream tree.
>
> I am mainly sad about this because this certainly means that only
> Qualcomm can make such ports by providing the "qtiseclib" that contains
> most of the functionality. Perhaps open-source code could have been
> adjusted by the community to other platforms with some effort.
>
> Thanks for reading.
> ~ Tom
>
> (1) https://trustedfirmware-a.readthedocs.io/en/latest/process/contributing.htm…
> (2) https://trustedfirmware-a.readthedocs.io/en/latest/plat/qti.html
> (3) https://github.com/ebs-universe/fpv-gcc
> (4) https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4885
> (5) https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4409
>
> Thank you all for your feedback.
>
> It appears that in theory we are all happy with using bloblist with few
> implementation details which needs to be taken care of during
> implementation.
>
Just to clarify: are you using "bloblist" as a general term for the concept
of a simple linked list of tagged data blobs, or to refer specifically to
the U-Boot implementation with that name? The existing TF-A implementation
(bl_aux_params) is basically identical in concept to the U-Boot bloblist,
but not binary compatible. Are we talking about just keeping that, or
throwing it away in order to reimplement the exact structure U-Boot is
using? (I would prefer to keep the bl_aux_params as they are to avoid
disrupting existing uses, of course. Making backwards-incompatible changes
to an interface that passes across multiple repos and firmware components
is always a big pain.)
Hi everyone,
I've just pushed a series to support FIP and FCONF on STM32MP1 platform.
I haven't put any TF-A maintainers yet, but feel free to comment.
Just be aware that I'll be out of office for the 3 and a half coming
weeks, so I won't be able to push new patch sets.
But I'll try to connect from time to time to answer questions, if any.
Best regards,
Yann
This event has been canceled with this note:
"Cancelling the TF-A Tech forum this week as the majority of attendees have
clashing events and cannot join."
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
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When: Thu Jul 15, 2021 4pm – 5pm United Kingdom Time
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Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
2 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 2 of 2 defect(s)
** CID 371992: Control flow issues (DEADCODE)
/plat/qemu/common/qemu_pm.c: 116 in qemu_validate_ns_entrypoint()
________________________________________________________________________________________________________
*** CID 371992: Control flow issues (DEADCODE)
/plat/qemu/common/qemu_pm.c: 116 in qemu_validate_ns_entrypoint()
110 /*
111 * Check if the non secure entrypoint lies within the non
112 * secure DRAM.
113 */
114 if ((entrypoint >= NS_DRAM0_BASE) &&
115 (entrypoint < (NS_DRAM0_BASE + NS_DRAM0_SIZE)))
>>> CID 371992: Control flow issues (DEADCODE)
>>> Execution cannot reach this statement: "return 0;".
116 return PSCI_E_SUCCESS;
117 return PSCI_E_INVALID_ADDRESS;
118 }
119
120 /*******************************************************************************
121 * Platform handler called when a CPU is about to enter standby.
** CID 371991: Control flow issues (NO_EFFECT)
/plat/qemu/common/qemu_pm.c: 115 in qemu_validate_ns_entrypoint()
________________________________________________________________________________________________________
*** CID 371991: Control flow issues (NO_EFFECT)
/plat/qemu/common/qemu_pm.c: 115 in qemu_validate_ns_entrypoint()
109 {
110 /*
111 * Check if the non secure entrypoint lies within the non
112 * secure DRAM.
113 */
114 if ((entrypoint >= NS_DRAM0_BASE) &&
>>> CID 371991: Control flow issues (NO_EFFECT)
>>> This less-than-zero comparison of an unsigned value is never true. "entrypoint < 0UL".
115 (entrypoint < (NS_DRAM0_BASE + NS_DRAM0_SIZE)))
116 return PSCI_E_SUCCESS;
117 return PSCI_E_INVALID_ADDRESS;
118 }
119
120 /*******************************************************************************
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u15810271.ct.sendgrid.net/ls/click?upn=HRESupC-2F2Czv4BOaCWWCy7my0P…
Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 1 of 1 defect(s)
** CID 364146: Control flow issues (DEADCODE)
/plat/mediatek/mt8195/plat_pm.c: 298 in plat_validate_power_state()
________________________________________________________________________________________________________
*** CID 364146: Control flow issues (DEADCODE)
/plat/mediatek/mt8195/plat_pm.c: 298 in plat_validate_power_state()
292 {
293 unsigned int pstate = psci_get_pstate_type(power_state);
294 unsigned int aff_lvl = psci_get_pstate_pwrlvl(power_state);
295 unsigned int cpu = plat_my_core_pos();
296
297 if (aff_lvl > PLAT_MAX_PWR_LVL) {
>>> CID 364146: Control flow issues (DEADCODE)
>>> Execution cannot reach this statement: "return -2;".
298 return PSCI_E_INVALID_PARAMS;
299 }
300
301 if (pstate == PSTATE_TYPE_STANDBY) {
302 req_state->pwr_domain_state[0] = PLAT_MAX_RET_STATE;
303 } else {
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u15810271.ct.sendgrid.net/ls/click?upn=HRESupC-2F2Czv4BOaCWWCy7my0P…
+ TF-A list that got dropped (again)!
Joanna
From: Joanna Farley <Joanna.Farley(a)arm.com>
Date: Wednesday, 2 June 2021 at 15:29
To: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>, Okash Khawaja <okash.khawaja(a)gmail.com>, Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>, Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>, Ed Stuber <edstuber(a)amperecomputing.com>, Arjun Khare <akhare(a)amperecomputing.com>, U-Boot Mailing List <u-boot(a)lists.denx.de>, Paul Isaac's <paul.isaacs(a)linaro.org>, Ron Minnich <rminnich(a)google.com>, Moe Ammar <moe(a)amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Hi Everyone,
The Manish Pandy and Madhukar Pappireddy of the TF-A team are planning to host another TF-A Tech Forum this Thursday to continue the live discussion.
Here is their agenda:
On tech forum this week, we would like to continue discussions on HOB list design.
The topics which we would like to cover is
1. Evaluate different proposals of passing information through boot phases.
2. If we don't get an agreement on one solution fit for all then we would try to get consensus for Infra segment platform(to solve original problem mentioned by Harb)
3. Try to get an agreement on size of tags and how "hybrid and tag only" HOB list can co-exist together?
Details of the call are:
======================
TF-A Tech Forum
When Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
Calendar tf-a(a)lists.trustedfirmware.org
Who • Bill Fletcher- creator
• tf-a(a)lists.trustedfirmware.org
We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
Trusted Firmware is inviting you to a scheduled Zoom meeting.
Join Zoom Meeting
https://zoom.us/j/9159704974
Meeting ID: 915 970 4974
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================
Joanna
On 19/05/2021, 03:50, "Madhukar Pappireddy" <Madhukar.Pappireddy(a)arm.com> wrote:
Attached slides presented by Manish in the TF-A tech forum.
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A
Sent: Tuesday, May 18, 2021 8:59 PM
To: Joanna Farley <Joanna.Farley(a)arm.com>; Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; tf-a(a)lists.trustedfirmware.org; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Hi,
I tried to summarize the discussions in the previous TF-A tech forum regarding the proposal to adopt Hand-off Blocks (HOBs) for passing information along the boot chain. I am certain I could not capture all suggestions/concerns brought up during the call. I apologize if I missed and/or misinterpreted any comments and would appreciate it if everyone could share their thoughts in response to this email thread.
The idea is to share information to other boot phases:
> Dynamic information: Created during runtime. Shared in the form of a chain of blobs(built as a linked list of C structure objects i.e., HOB list).
> Static information: Known at compile time. Historically, shared through the use of Device Tree/ACPI tables
Both the above requirements are common in many ecosystems and need to co-exist.
There are broadly 3 problems to solve:
1. Format of HOB structures: It looks like the consensus is that we could use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in u-boot).
2. Identification of HOB list entries: There is a debate about whether tags would suffice or if the HOB list producer and consumer would depend on UUID/GUIDs for identifying a specific HOB structure. Another suggestion was to use a hybrid approach. Reserve a single tag ID for identifying/constructing a HOB structure that further leverages UUID based identifier. This way, the generic HOB list doesn't need to support UUIDs and can work with tags.
3. The design contract for the static interface between two boot phases: The problem at hand is whether to pass a pointer to a HOB list or a device tree blob through the general-purpose registers for configuration hand-off between two boot phases. Some proposals that came up:
> Proposal 1: Always pass a pointer to the device tree blob through the GP register and capture the pointer to the HOB list as a property of a node that is uniquely identifiable by the downstream boot phase. This needs to define a device tree binding such that producer and consumer agree on the information passed.
> Proposal 2: Pass a pointer to a generic container through the GP register that can be interpreted appropriately by both boot loaders(i.e., producer and consumer of the boot info). This container can either be a dtb or a HOB list which can be simply inferred by checking for a magic header that indicates if the buffer appears to be a flattened device tree.
> One another concern that was brought up offline is to make sure we don't break current design contracts between various boot loader phases in TF-A. Many of the general-purpose registers have a designated purpose such as to share configurations between BL images( such as firmware config dtb, SoC config dtb, Non trusted firmware config dtb, memory layout, entry point info, etc.).
If I am not mistaken, a single design may not fit the needs of every segment(client, Infra, embedded) and the forum is open to solutions tailored for individual segments. Joanna will be sending a follow up email with more information about future TF-A tech forums that serves as a platform for further discussions.
Thanks,
Madhukar
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A
Sent: Sunday, May 16, 2021 5:19 AM
To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Apologies I failed with the recording. Manish/Madhu will reply early next week with the slides and some notes to help with a follow up session which we hope to hold this Thursday. Invite and agenda will also be sent out early next week.
Thanks
Joanna
On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi,
Do we have slides and video from last week's discussion?
Thanks,
Okash
On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> Thanks for the idea. I am still not completely sure what benefit UUID provides to an open project. I'd like to propose something different, more in the spirit of open collaboration. I also worry that the word 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring closed-source firmware and the continued decline of open-source projects. It really should not be.
>
> So I suggest: Use simple integer IDs and reserve some area for 'private' use. If you want to collaborate across projects outside your company, you either need to allocate a 'public' ID or agree privately between the parties which private ID to use.
>
> This means that the default and easiest option is for collaboration and a public ID, with private ones (whose purpose may be secret) reserved just for private use.
>
> Regards,
> Simon
>
> On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hey Folks,
>>
>> We wanted to put out a middle-ground proposal to help guide the discussion on the call tomorrow.
>>
>>
>>
>> A proposal that we have been discussing offline involves reserving a single tag ID for the purpose of construction UEFI PI HOB List structure, and that tag would be used to identify a HOB-specific structure that does leverage UUID based identifier. This will eliminate the burden of having to support UUID as the tag, and this enables projects that require UUID based identifiers for the broad range of HOB structures that need to be produced during the booting of the platform. Once we have a tag for a HOB list, this will enable various HOB producers that can add/extend the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other side (i.e. whatever the BL33 image is booting on that platform).
>>
>>
>>
>> Essentially, the idea is if someone would like to support HOB structures in a standard way using TF-A, they would wrap it up in a BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we identify the structure as a HOB list is with this new reserved tag.
>>
>>
>>
>> Hopefully that makes sense and less contentious. Look forward to discuss this further on the call.
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Sent: Friday, April 30, 2021 8:14 AM
>> To: François Ozog <francois.ozog(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi All,
>>
>>
>>
>> Please find invite for next TF-A Tech Forum session to continue our discussions on HOB implementation, feel free to forward it to others.
>>
>>
>>
>> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
>>
>>
>>
>> Agenda:
>>
>> Discussion Session: Static and Dynamic Information Handling in TF-A
>>
>> Lead by Manish Pandey and Madhukar Pappireddy
>>
>> · There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
>>
>> The requirement is two-fold:
>>
>> 1. Passing static information(config files)
>>
>> 2. Passing dynamic information (Hob list)
>>
>> In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
>>
>>
>>
>> The two specific item which we would like to discuss are:
>>
>> 1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
>>
>> 2. Standardization on Physical register use to pass base of HoB data structure.
>>
>> References:
>>
>> [1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
>>
>> [2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
>>
>>
>>
>> Thanks
>>
>>
>>
>> Joanna
>>
>>
>>
>> You have been invited to the following event.
>>
>> TF-A Tech Forum
>>
>> When
>>
>> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
>>
>> Calendar
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> Who
>>
>> •
>>
>> Bill Fletcher- creator
>>
>> •
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> more details »
>>
>>
>>
>> We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
>>
>>
>>
>> Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
>>
>>
>>
>> Trusted Firmware is inviting you to a scheduled Zoom meeting.
>>
>>
>>
>> Join Zoom Meeting
>>
>> https://zoom.us/j/9159704974
>>
>>
>>
>> Meeting ID: 915 970 4974
>>
>>
>>
>> One tap mobile
>>
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>>
>> +16699009128,,9159704974# US (San Jose)
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>> Meeting ID: 915 970 4974
>>
>> Find your local number: https://zoom.us/u/ad27hc6t7h
>>
>>
>>
>> ________________________________
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: 08 April 2021 16:50
>> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi
>>
>>
>>
>> here is the meeting recording:
>>
>> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%z
>>
>>
>>
>> I am really sorry about the confusion related to the meeting time. I have now understood: the Collaborate portal uses a specific calendar which is tied to US/Chicago timezone while the actual Google Calendar is tied to Central Europe timezone. I am going to drop the Collaborate portal and use a shared Google calendar (it should be visible on the trusted-substrate.org page).
>>
>>
>>
>> I'll try to summarize what I learnt and highlight my view on what can be next steps in a future mail.
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
>>
>>
>>
>> To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
>>
>>
>>
>> The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
>>
>>
>>
>> One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
>>
>>
>>
>> Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
>>
>>
>>
>> Looking forward to having further discussions on zoom call today.
>>
>>
>>
>> Thanks
>>
>> Manish P
>>
>>
>>
>> ________________________________
>>
>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
>> Sent: 25 March 2021 02:43
>> To: Simon Glass <sjg(a)chromium.org>
>> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
>>
>>
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>>
>>
>> It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
>>
>>
>>
>> I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
>>
>>
>>
>> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi Harb,
>>
>>
>>
>> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hello Folks,
>>
>> Appreciate the feedback and replies on this. Glad to see that there is interest in this topic.
>>
>>
>>
>> I try to address the comments/feedback from Francois and Simon below….
>>
>>
>>
>> @François Ozog – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
>>
>>
>>
>> Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
>>
>>
>>
>> The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
>>
>>
>>
>> Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
>>
>> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
>> “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
>>
>>
>>
>> Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
>>
>>
>>
>> To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
>>
>>
>>
>> I understand the versatility of DT, but I see two major problems with DT:
>>
>> DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
>> DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
>>
>>
>>
>> I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
>>
>>
>>
>> Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
>>
>>
>>
>> Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
>>
>>
>>
>> @Simon Glass - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
>>
>>
>>
>> That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
>>
>>
>>
>> The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
>>
>>
>>
>> I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
>>
>>
>>
>> True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
>>
>>
>>
>> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
>> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
>> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
>>
>> (etc.)
>>
>>
>>
>> static struct guid_name {
>> efi_guid_t guid;
>> const char *name;
>> } guid_name[] = {
>> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
>> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
>> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
>> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
>> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
>> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
>>
>> (never figured out what those two are)
>>
>>
>> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
>> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
>> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
>> { {}, "zero-guid" },
>> {}
>> };
>>
>> static const char *guid_to_name(const efi_guid_t *guid)
>> {
>> struct guid_name *entry;
>>
>> for (entry = guid_name; entry->name; entry++) {
>> if (!guidcmp(guid, &entry->guid))
>> return entry->name;
>> }
>>
>> return NULL;
>> }
>>
>>
>>
>> Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
>>
>>
>>
>>
>>
>> We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
>>
>>
>>
>> Indeed. There is certainly value in both approaches.
>>
>>
>>
>> Regards,
>>
>> Simon
>>
>>
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: Tuesday, March 23, 2021 10:00 AM
>> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> +Ron Minnich +Paul Isaac's
>>
>>
>>
>> Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
>>
>>
>>
>> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> I propose we cover the topic at the next Trusted Substrate zoom call on April 8th 4pm CET.
>>
>>
>>
>> The agenda:
>>
>> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
>>
>> runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
>>
>>
>>
>> For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
>>
>> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
>>
>> This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
>>
>> HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
>>
>>
>>
>> There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
>>
>> I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
>>
>>
>>
>> Requirements (to be validated):
>>
>> - ACPI and DT hardware descriptions.
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
>>
>> - at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
>>
>> - support secure world device assignment
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>>
>>
>> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
>>
>> Hi,
>>
>> Can I suggest using bloblist for this instead? It is lightweight,
>> easier to parse, doesn't have GUIDs and is already used within U-Boot
>> for passing info between SPL/U-Boot, etc.
>>
>> Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
>> Header file describes the format:
>> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>>
>> Full set of unit tests:
>> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>>
>> Regards,
>> Simon
>>
>> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org> wrote:
>> >
>> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
>> >
>> > standardization is very much welcomed here and need to accommodate a very
>> > diverse set of situations.
>> > For example, TEE OS may need to pass memory reservations to BL33 or
>> > "capture" a device for the secure world.
>> >
>> > I have observed a number of architectures:
>> > 1) pass information from BLx to BLy in the form of a specific object
>> > 2) BLx called by BLy by a platform specific SMC to get information
>> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
>> > fixups
>> >
>> > I also imagined a standardized "broadcast" FF-A call so that any firmware
>> > element can either provide information or "do something".
>> >
>> > My understanding of your proposal is about standardizing on architecture 1)
>> > with the HOB format.
>> >
>> > The advantage of the HOB is simplicity but it may be difficult to implement
>> > schemes such as pruning a DT because device assignment in the secure world.
>> >
>> > In any case, it looks feasible to have TF-A and OP-TEE complement the list
>> > of HOBs to pass information downstream (the bootflow).
>> >
>> > It would be good to start with building the comprehensive list of
>> > information that need to be conveyed between firmware elements:
>> >
>> > information. | authoritative entity | reporting entity | information
>> > exchanged:
>> > dram | TFA | TFA |
>> > <format to be detailed, NUMA topology to build the SRAT table or DT
>> > equivalent?>
>> > PSCI | SCP | TFA? |
>> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
>> > secure SRAM | TFA. | TFA. |
>> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
>> > other? | |
>> > |
>> >
>> > Cheers
>> >
>> > FF
>> >
>> >
>> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
>> > tf-a(a)lists.trustedfirmware.org> wrote:
>> >
>> > > Hello Folks,
>> > >
>> > >
>> > >
>> > > I'm emailing to start an open discussion about the adoption of a concept
>> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
>> > > Framework Architecture (FFA). This is something that is a pretty major
>> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
>> > > designed to enable a broad range of highly configurable datacenter
>> > > platforms.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > What is a HOB (Background)?
>> > >
>> > > ---------------------------
>> > >
>> > > UEFI PI spec describes a particular definition for how HOB may be used for
>> > > transitioning between the PEI and DXE boot phases, which is a good
>> > > reference point for this discussion, but not necessarily the exact solution
>> > > appropriate for TF-A.
>> > >
>> > >
>> > >
>> > > A HOB is simply a dynamically generated data structure passed in between
>> > > two boot phases. This is information that was obtained through discovery
>> > > and needs to be passed forward to the next boot phase *once*, with no API
>> > > needed to call back (e.g. no call back into previous firmware phase is
>> > > needed to fetch this information at run-time - it is simply passed one time
>> > > during boot).
>> > >
>> > >
>> > >
>> > > There may be one or more HOBs passed in between boot phases. If there are
>> > > more than one HOB that needs to be passed, this can be in a form of a "HOB
>> > > table", which (for example) could be a UUID indexed array of pointers to
>> > > HOB structures, used to locate a HOB of interest (based on UUID). In such
>> > > cases, instead of passing a single HOB, the boot phases may rely on passing
>> > > the pointer to the HOB table.
>> > >
>> > >
>> > >
>> > > This has been extremely useful concept to employ on highly configurable
>> > > systems that must rely on flexible discovery mechanisms to initialize and
>> > > boot the system. This is especially helpful when you have multiple
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Why do we need HOBs in TF-A?:
>> > >
>> > > -----------------------------
>> > >
>> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
>> > > a way that is SoC specific *but* platform agnostic. This means that a
>> > > single ARM SoC that a SiP may deliver to customers may provide a single
>> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
>> > > range of platform designs and configurations in order to boot a platform
>> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
>> > > achieve this, the platform configuration must be *discovered* instead of
>> > > statically compiled as it is today in TF-A via device tree based
>> > > enumeration. The mechanisms of discovery may differ broadly depending on
>> > > the relevant industry standard, or in some cases may have rely on SiP
>> > > specific discovery flows.
>> > >
>> > >
>> > >
>> > > For example: On server systems that support a broad range DIMM memory
>> > > population/topologies, all the necessary information required to boot is
>> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
>> > > I2C bus. Leveraging the SPD bus, may platform variants could be supported
>> > > with a single TF-A binary. Not only is this information required to
>> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
>> > > phases will also need this SPD info to construct a system physical address
>> > > map and properly initialize the MMU based on the memory present, and where
>> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
>> > > need to generate standard firmware tables to the operating systems, such as
>> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
>> > > SRAT, even NFIT if NVDIMM's are present).
>> > >
>> > >
>> > >
>> > > In short, it all starts with a standardized or vendor specific discovery
>> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
>> > > information to the next boot stages (e.g. BL31/BL32/BL33).
>> > >
>> > >
>> > >
>> > > Today, every HOB may be a vendor specific structure, but in the future
>> > > there may be benefit of defining standard HOBs. This may be useful for
>> > > memory discovery, passing the system physical address map, enabling TPM
>> > > measured boot, and potentially many other common HOB use-cases.
>> > >
>> > >
>> > >
>> > > It would be extremely beneficial to the datacenter market segment if the
>> > > TF-A community would adopt this concept of information passing between all
>> > > boot phases as opposed to rely solely on device tree enumeration. This is
>> > > not intended to replace device tree, rather intended as an alternative way
>> > > to describe the info that must be discovered and dynamically generated.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Conclusion:
>> > >
>> > > -----------
>> > >
>> > > We are proposing that the TF-A community begin pursuing the adoption of
>> > > HOBs as a mechanism used for information exchange between each boot stage
>> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
>> > > want to explore standardizing some HOB structures for the BL33 phase (e.g.
>> > > UEFI HOB structures), but initially would like to agree on this being a
>> > > useful mechanism used to pass information between each boot stage.
>> > >
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > --Harb
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > --
>> > > TF-A mailing list
>> > > TF-A(a)lists.trustedfirmware.org
>> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> > >
>> >
>> >
>> > --
>> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
>> > T: +33.67221.6485
>> > francois.ozog(a)linaro.org | Skype: ffozog
>> > _______________________________________________
>> > boot-architecture mailing list
>> > boot-architecture(a)lists.linaro.org
>> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>
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Hi,
Is the question strictly related to this platform not implementing the mentioned errata (for which a platform change can be emitted)? Or is it more generally that those "missing errata warnings" are not printed in release mode?
Assuming the latter, it looks to me it is the integrator mistake to not include the appropriate mitigations at development phase (hence while using debug mode for building TF-A).
Then when the device is deployed (hence most often built for release mode), if this message is printed it is an indication for a malicious agent that such attack vector through mis-implemented errata is possible. So the consequence is possibly even worst than just "missing" to include the errata.
Other TF-Aers (Bipin?) may have other opinions?
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Pali Rohár via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 28 June 2021 15:36
To: tf-a(a)lists.trustedfirmware.org
Cc: Konstantin Porotchkin; Marek Behún
Subject: [TF-A] Missing CPU workaround warning message
Hello! If TF-A for Marvell Armada 3720 platform is compiled in debug
mode then at runtime it prints following warning messages:
WARNING: BL1: cortex_a53: CPU workaround for 855873 was missing!
WARNING: BL1: cortex_a53: CPU workaround for 1530924 was missing!
These lines are not printed in non-debug mode. It is an issue?
--
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Hi,
I tend to agree with Soby here. If the normal world and EL3 share the
console, EL3 error messages/debug prints exposed to the normal world could
be another potential attack vector. From a functionality perspective, will
there not be contention issues on multi-core platforms and hence garbled
output?
I understand that using two separate UARTS may not be possible for many
platforms, in which case a single UART can be shared during cold boot
between EL3 and the normal world, while EL3 runtime messages can be logged
to a secure memory buffer. Once boot exists EL3, UART ownership can be
transferred to the normal world.
Thanks,
Mayur
On Wed, Jun 23, 2021 at 5:00 AM Soby Mathew via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> Hi Michal,
> Sure, platform can choose to share but I was bringing up the potential
> attack vector of Non Secure being able to hang up EL3 if EL3 has runtime
> prints and the Non secure is able to disable or control the UART used by
> EL3. Typically , runtime logs are disabled on production builds so this
> might not be a problem anyway.
>
> Regarding crash console, the plat_crash_console_init() can initialize a
> stack (either the EL3 runtime stack or a dedicated crash stack) and use C
> runtime to control clocks for crash logs. So the current assembly
> implementation should not be a gating factor for doing clock control if
> required.
>
> Best Regards
> Soby Mathew
>
> > -----Original Message-----
> > From: Michal Simek <michal.simek(a)xilinx.com>
> > Sent: Wednesday, June 23, 2021 9:16 AM
> > To: Varun Wadekar <vwadekar(a)nvidia.com>; Soby Mathew
> > <Soby.Mathew(a)arm.com>; Michal Simek <michal.simek(a)xilinx.com>
> > Cc: tf-a(a)lists.trustedfirmware.org
> > Subject: Re: [TF-A] PL011 clock handling between TF-A and Linux
> >
> > Hi,
> >
> > I agree with Varun. TF-A can use DCC console but it is not practical.
> > Using second console is definitely an option but not all platforms and
> also
> > monitoring two consoles is problematic.
> >
> > Also OP-TEE is touching this primary console. Platform which are using
> DT are
> > looking for chosen node (as backup) and read information about OS console
> > from it.
> >
> > Thanks,
> > Michal
> >
> > On 6/22/21 8:47 PM, Varun Wadekar wrote:
> > > Hi Soby,
> > >
> > > Even though in principle I agree with you, it is not practical to add
> secure
> > only UART port to a platform. It is shared for multiple reasons - e.g.
> lower
> > board cost. That is the case on all Tegra Jetson platforms.
> > >
> > > This means that the secure world never owns the console - not even
> during
> > cold boot. The crash console code is in assembly today. This makes
> > implementing code to communicate to an external clock manager is not
> > straight forward and platforms might choose to keep the code to toggle
> > clock/reset out of TF-A.
> > >
> > > -Varun
> > >
> > > -----Original Message-----
> > > From: Soby Mathew <Soby.Mathew(a)arm.com>
> > > Sent: Tuesday, June 22, 2021 4:30 PM
> > > To: Michal Simek <michal.simek(a)xilinx.com>; Varun Wadekar
> > > <vwadekar(a)nvidia.com>
> > > Cc: tf-a(a)lists.trustedfirmware.org
> > > Subject: RE: [TF-A] PL011 clock handling between TF-A and Linux
> > >
> > > External email: Use caution opening links or attachments
> > >
> > >
> > > Hi Michal,
> > > The general security rule of thumb is, any UART `owned` by Secure
> world (
> > including EL3) should not be accessible/or controlled by Non Secure and
> this
> > includes control of the clocks as well. Hence sharing of UART /
> management
> > of Secure world UART clocks by Linux seems problematic to me.
> > >
> > > There are 3 types of consoles needed in TF-A. The first one is the
> cold boot
> > console, the second one is runtime console and the 3rd is crash console.
> The
> > cold boot console is initially owned by Secure world as part boot
> process and
> > once execution is transferred to Non Secure, the ownership of the UART
> also
> > is transferred.
> > > Regarding clock expectations, the runtime UART is always expected to be
> > ON but then this depends on the TF-A build config as it is very rare to
> have any
> > runtime logs from Secure world and hence this config may be restricted to
> > development builds of TF-A. For the crash console, the clocks don't need
> to
> > enabled all the time and any init needed can be performed as part of
> > plat_crash_console_init().
> > >
> > > HTH,
> > > Best Regards
> > > Soby Mathew
> > >
> > >> -----Original Message-----
> > >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> > >> Michal Simek via TF-A
> > >> Sent: Tuesday, June 22, 2021 2:03 PM
> > >> To: Varun Wadekar <vwadekar(a)nvidia.com>; Michal Simek
> > >> <michal.simek(a)xilinx.com>
> > >> Cc: tf-a(a)lists.trustedfirmware.org
> > >> Subject: Re: [TF-A] PL011 clock handling between TF-A and Linux
> > >>
> > >> Hi Varun,
> > >>
> > >> do you have any links to that calls in Linux clk API? I expect the
> > >> same hooks should be added also to reset.
> > >>
> > >> And is TF-A informs your special firmware that for example serial
> > >> driver is used by TF-A to increate refcount?
> > >>
> > >> Thanks,
> > >> Michal
> > >>
> > >> On 6/22/21 2:03 PM, Varun Wadekar wrote:
> > >>> Hi Michal,
> > >>>
> > >>> Tegra platforms manage clocks/resets by special firmware. The
> > >>> firmware
> > >> internally manages refcount of users as you described.
> > >>>
> > >>> AFAIR, we placed calls to the firmware in the linux clk APIs to
> achieve this.
> > >> There was an effort to leverage runtime_pm for this too.
> > >>>
> > >>> I think we wont be able to add guidance to TF-A for clock management
> > >>> as
> > >> most of it is platform dependent. We can add a generic guideline
> > >> saying that a certain driver expects the platform to manage the
> clock/reset
> > for the IP.
> > >>>
> > >>> -Varun
> > >>>
> > >>> -----Original Message-----
> > >>> From: Michal Simek <michal.simek(a)xilinx.com>
> > >>> Sent: Tuesday, June 22, 2021 7:24 AM
> > >>> To: Varun Wadekar <vwadekar(a)nvidia.com>; Michal Simek
> > >>> <michal.simek(a)xilinx.com>
> > >>> Cc: tf-a(a)lists.trustedfirmware.org
> > >>> Subject: Re: [TF-A] PL011 clock handling between TF-A and Linux
> > >>>
> > >>> External email: Use caution opening links or attachments
> > >>>
> > >>>
> > >>> Hi Varun,
> > >>>
> > >>> Xilinx is also managing it by special firmware. There is a concept
> > >>> of
> > >> protected-clocks documented via DT binding which is used by Qualcomm.
> > >>>
> > >>> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/
> > >>> tr
> > >>> ee/Documentation/devicetree/bindings/clock/clock-bindings.txt?h=next
> > >>> -2
> > >>> 0210621#n172
> > >>>
> > >>> Are you also using this feature or simply don't let Linux know about
> > >>> these
> > >> clocks at all or simulate it via fixed-clock or so?
> > >>> Or any registration is in place that firmware keep refcount of users
> > >>> and
> > >> don't let it change unless there is only one user of that clock?
> > >>>
> > >>> Thanks,
> > >>> Michal
> > >>>
> > >>> On 6/21/21 6:41 PM, Varun Wadekar wrote:
> > >>>> Hi Michal,
> > >>>>
> > >>>> AFAIK, TF-A does not publish guidelines for clocks/resets for
> > >>>> shared IP. It
> > >> is left to the platforms.
> > >>>>
> > >>>> For Tegra platforms, the clocks/reset are managed by a central
> > >>>> entity. TF-
> > >> A is expected to co-ordinate with this entity. Unfortunately, PL011
> > >> does not fall in this category and is expected to be kept on by the
> previous
> > bootloader.
> > >>>>
> > >>>> -Varun
> > >>>>
> > >>>> -----Original Message-----
> > >>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> > >>>> Michal Simek via TF-A
> > >>>> Sent: Monday, June 21, 2021 2:24 PM
> > >>>> To: tf-a(a)lists.trustedfirmware.org
> > >>>> Subject: [TF-A] PL011 clock handling between TF-A and Linux
> > >>>>
> > >>>> External email: Use caution opening links or attachments
> > >>>>
> > >>>>
> > >>>> Hi,
> > >>>>
> > >>>> recently we have hit the case where Linux has pl011 driver and
> > >>>> using it as
> > >> a console. The same console is also used by TF-A. If you look at
> > >> implementation details Linux pl011 driver has in
> > >> pl011_console_write() clk_enable/clk_disable calls.
> > >>>> I can't see any clock handling for PL011 in TF-A that's why I guess
> > >>>> that TF-A
> > >> expectation is that clocks are enabled and must be enabled all the
> > >> time because pl011 is also used as crashed console.
> > >>>> That's why I would like to check with you what's the clock
> > >>>> expectation in
> > >> these shared IP cases.
> > >>>> Do you have a requirement that firmware should keep refcount of IP
> > >> users and never disable clock when only one requires it?
> > >>>>
> > >>>> Thanks,
> > >>>> Michal
> > >>>> --
> > >>>> TF-A mailing list
> > >>>> TF-A(a)lists.trustedfirmware.org
> > >>>>
> > >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flis
> > >>>> t
> > >>>> s.trustedfirmware.org%2Fmailman%2Flistinfo%2Ftf-
> > >> a&data=04%7C01%7C
> > >>>>
> > >>
> > vwadekar%40nvidia.com%7C9d5af04d3aba49b18cc808d935465267%7C4308
> > 3
> > >> d1572
> > >>>>
> > >>
> > 7340c1b7db39efd9ccc17a%7C0%7C0%7C637599398425726681%7CUnknow
> > n%
> > >> 7CTWFpb
> > >>>>
> > >>
> > GZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
> > >> 6Mn
> > >>>>
> > >>
> > 0%3D%7C1000&sdata=%2BXFRPZTttom4rvT%2FmEcQnbgSa276PYuKbvo
> > >> H4VujRk8
> > >>>> %3D&reserved=0
> > >>>>
> > >> --
> > >> TF-A mailing list
> > >> TF-A(a)lists.trustedfirmware.org
> > >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flis
> > >> t
> > >> s.trustedfirmware.org%2Fmailman%2Flistinfo%2Ftf-
> > a&data=04%7C01%7C
> > >> v
> > >>
> > wadekar%40nvidia.com%7C957021cd030643da94bc08d935928f6b%7C4308
> > 3d15727
> > >> 3
> > >>
> > 40c1b7db39efd9ccc17a%7C0%7C0%7C637599725858916982%7CUnknown%
> > 7CTWFpbGZ
> > >> s
> > >>
> > b3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn
> > 0%3
> > >> D
> > >>
> > %7C2000&sdata=S0D%2FZ5rk6Wr3xyIdCmol0eigIo%2FlGn%2B2WJODig
> > %2FeDqU
> > >> %
> > >> 3D&reserved=0
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>
Hi
Following a discussion with Civil Infrastructure Project TSC, there is
a watchdog protection issue with EFI: the time between the call to
ExitBootService and Linux kernel takes over watchdog service is not
covered by any watchdog protection.
The EFI specification for BS.SetWatchdogTimer is very flexible as it
states "perform a platform specific action that must eventually cause
the platform to be reset.".
So we could naively implement a solution that would arm platform
hardware watchdog in addition to EFI timer. Assuming watchdog period
is long enough that it cover the time for Linux to take over the
hardware watchdog, there is nothing to be done in EFI Stub to benefit
from the new protection.
But this scheme fails to handle FF-A update capsules which can take a
long time. So either the period is long enough to support that or we
need a FF-A watchdog service. Based on Siemens feedback, time to
update can last 20 minutes. StandAloneMM may also need such a
protection so FF-A watchdog service seems desired.
I'd be happy to receive feedback on the problem itself (watchdog in
EFI) and on the possible solution (FF-A based).
Cheers
FF
Hello TF-A partners!
As you may know, Arm recently announced the v8-R64 Architecture (AArch64 R-class cores), notably the Cortex R-82. v8-R64 has generated a lot of interest in the R-cores community, in part because of its vastly-increased address space and performance, and also because of its ability to run rich operating systems like Linux alongside more traditional RTOSes.
Of course, great hardware requires great firmware to succeed! So, we are upstreaming a new platform into TF-A to support v8-R64, called "fvp_r." It's certainly reasonable to ask, "why support v8-R64 as a platform under the A-cores' trusted firmware?" The answer is simply that v8-R64 cores are far more similar with v8-A cores than different. Therefore, most of the trusted firmware code for v8-R64 cores is in-common with v8-A cores. If a separate trusted-firmware project were created for them, we would have a huge parallel-maintenance headache! Also, SystemReady IR certification for v8-R64 cores requires compliance with EBBR, and building from a TF-A framework puts us on the path toward that goal.
The immediate firmware requirement for v8-R64, however, is not the entirety of TF-A. The immediate requirement for the fvp_r platform is to let the partner/customer dictate the nature of the run-time environment, and for TF to "trusted-boot" their environment. Therefore, the patch that we're upstreaming boots up only through BL1, and BL1 is adapted to load the customer/partner custom-defined run-time system.
On 1 July, the Arm team who are upstreaming the fvp_r platform, will host a Tech Forum session wherein we'll provide an overview, and medium level of detail on:
* The differences between v8-A and v8-R64 (again, more similar than different!),
* The impacts of these differences upon BL1, and
* Changes to BL1 to boot a partner/customer run-time system.
* We'll then detail the nature of the patches involved - which patches provide what functionality.
* Provide some suggestions for making the review of these patches easier.
________________________________
You have been invited to the following event.
TF-A Tech Forum
When
Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
Calendar
tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
Who
*
Bill Fletcher- creator
*
tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
more details ><https://www.google.com/calendar/event?action=VIEW&eid=NWlub3Ewdm1tMmk1cTJrM…>
We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/<https://www.google.com/url?q=https%3A%2F%2Fwww.trustedfirmware.org%2Fmeetin…>
Trusted Firmware is inviting you to a scheduled Zoom meeting.
Join Zoom Meeting
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Meeting ID: 915 970 4974
Hello! If TF-A for Marvell Armada 3720 platform is compiled in debug
mode then at runtime it prints following warning messages:
WARNING: BL1: cortex_a53: CPU workaround for 855873 was missing!
WARNING: BL1: cortex_a53: CPU workaround for 1530924 was missing!
These lines are not printed in non-debug mode. It is an issue?
Hi Michal,
The general security rule of thumb is, any UART `owned` by Secure world ( including EL3) should not be accessible/or controlled by Non Secure and this includes control of the clocks as well. Hence sharing of UART / management of Secure world UART clocks by Linux seems problematic to me.
There are 3 types of consoles needed in TF-A. The first one is the cold boot console, the second one is runtime console and the 3rd is crash console. The cold boot console is initially owned by Secure world as part boot process and once execution is transferred to Non Secure, the ownership of the UART also is transferred.
Regarding clock expectations, the runtime UART is always expected to be ON but then this depends on the TF-A build config as it is very rare to have any runtime logs from Secure world and hence this config may be restricted to development builds of TF-A. For the crash console, the clocks don’t need to enabled all the time and any init needed can be performed as part of plat_crash_console_init().
HTH,
Best Regards
Soby Mathew
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Michal
> Simek via TF-A
> Sent: Tuesday, June 22, 2021 2:03 PM
> To: Varun Wadekar <vwadekar(a)nvidia.com>; Michal Simek
> <michal.simek(a)xilinx.com>
> Cc: tf-a(a)lists.trustedfirmware.org
> Subject: Re: [TF-A] PL011 clock handling between TF-A and Linux
>
> Hi Varun,
>
> do you have any links to that calls in Linux clk API? I expect the same hooks
> should be added also to reset.
>
> And is TF-A informs your special firmware that for example serial driver is
> used by TF-A to increate refcount?
>
> Thanks,
> Michal
>
> On 6/22/21 2:03 PM, Varun Wadekar wrote:
> > Hi Michal,
> >
> > Tegra platforms manage clocks/resets by special firmware. The firmware
> internally manages refcount of users as you described.
> >
> > AFAIR, we placed calls to the firmware in the linux clk APIs to achieve this.
> There was an effort to leverage runtime_pm for this too.
> >
> > I think we wont be able to add guidance to TF-A for clock management as
> most of it is platform dependent. We can add a generic guideline saying that
> a certain driver expects the platform to manage the clock/reset for the IP.
> >
> > -Varun
> >
> > -----Original Message-----
> > From: Michal Simek <michal.simek(a)xilinx.com>
> > Sent: Tuesday, June 22, 2021 7:24 AM
> > To: Varun Wadekar <vwadekar(a)nvidia.com>; Michal Simek
> > <michal.simek(a)xilinx.com>
> > Cc: tf-a(a)lists.trustedfirmware.org
> > Subject: Re: [TF-A] PL011 clock handling between TF-A and Linux
> >
> > External email: Use caution opening links or attachments
> >
> >
> > Hi Varun,
> >
> > Xilinx is also managing it by special firmware. There is a concept of
> protected-clocks documented via DT binding which is used by Qualcomm.
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tr
> > ee/Documentation/devicetree/bindings/clock/clock-bindings.txt?h=next-2
> > 0210621#n172
> >
> > Are you also using this feature or simply don't let Linux know about these
> clocks at all or simulate it via fixed-clock or so?
> > Or any registration is in place that firmware keep refcount of users and
> don't let it change unless there is only one user of that clock?
> >
> > Thanks,
> > Michal
> >
> > On 6/21/21 6:41 PM, Varun Wadekar wrote:
> >> Hi Michal,
> >>
> >> AFAIK, TF-A does not publish guidelines for clocks/resets for shared IP. It
> is left to the platforms.
> >>
> >> For Tegra platforms, the clocks/reset are managed by a central entity. TF-
> A is expected to co-ordinate with this entity. Unfortunately, PL011 does not
> fall in this category and is expected to be kept on by the previous bootloader.
> >>
> >> -Varun
> >>
> >> -----Original Message-----
> >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> >> Michal Simek via TF-A
> >> Sent: Monday, June 21, 2021 2:24 PM
> >> To: tf-a(a)lists.trustedfirmware.org
> >> Subject: [TF-A] PL011 clock handling between TF-A and Linux
> >>
> >> External email: Use caution opening links or attachments
> >>
> >>
> >> Hi,
> >>
> >> recently we have hit the case where Linux has pl011 driver and using it as
> a console. The same console is also used by TF-A. If you look at
> implementation details Linux pl011 driver has in pl011_console_write()
> clk_enable/clk_disable calls.
> >> I can't see any clock handling for PL011 in TF-A that's why I guess that TF-A
> expectation is that clocks are enabled and must be enabled all the time
> because pl011 is also used as crashed console.
> >> That's why I would like to check with you what's the clock expectation in
> these shared IP cases.
> >> Do you have a requirement that firmware should keep refcount of IP
> users and never disable clock when only one requires it?
> >>
> >> Thanks,
> >> Michal
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >>
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flis
> >> t
> >> s.trustedfirmware.org%2Fmailman%2Flistinfo%2Ftf-
> a&data=04%7C01%7C
> >>
> vwadekar%40nvidia.com%7C9d5af04d3aba49b18cc808d935465267%7C43083
> d1572
> >>
> 7340c1b7db39efd9ccc17a%7C0%7C0%7C637599398425726681%7CUnknown%
> 7CTWFpb
> >>
> GZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
> 6Mn
> >>
> 0%3D%7C1000&sdata=%2BXFRPZTttom4rvT%2FmEcQnbgSa276PYuKbvo
> H4VujRk8
> >> %3D&reserved=0
> >>
> --
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> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi,
See few comments inline [OD]
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 16 June 2021 11:41
To: tf-a(a)lists.trustedfirmware.org
Cc: Raghupathy Krishnamurthy; Nicolas Benech
Subject: [TF-A] SP manifest: avoid manual updates to "entrypoint-offset"
Hello,
We (Nico/Raghu) have been implementing SEL0 partitions for Tegra platforms
[OD] Just to be clear, is this about SEL0 partitions using an SEL1 shim (as per https://review.trustedfirmware.org/q/topic:%22db%252Fsel0%22+(status:open%2… )?
and recently hit an issue, where the “entrypoint-offset” field of the SP manifest [1] cannot cope with increasing manifest blobs. The way the SP manifest is created today, the “entrypoint-offset” field is set to a value *statically* by the implementer. Down the line if the manifest grows past the value written in the “entrypoint-offset”, we must manually update it. This needs to be fixed.
We believe there is an opportunity to upgrade the sptool to handle this situation during SP package creation, where sptool calculates the manifest size and bumps the “entrypoint-offset” past the end of the manifest. There are other ways of patching the SP manifest at runtime, but they seem sub-optimal.
Please let me know if there are other ideas to solve this problem. I will post a patch to update the sptool shortly but wanted to get the ball rolling.
[OD] We had an attempt (https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/8536) to move the entry point farther in the image such that we can support 64KB granules in the Stage-1 translation regime. This does not relate exactly to your problem but the effect is the "same" (aka there is more room for the manifest dtb). Agree this still requires hard-coding the entry point. At this stage I had thought of pushing the entry point even farther at a reasonably large 64KB aligned offset such that it helps with both problems.
Cheers.
[1] 14. FF-A manifest binding to device tree — Trusted Firmware-A documentation<https://trustedfirmware-a.readthedocs.io/en/latest/components/ffa-manifest-…>
Hi Michal,
AFAIK, TF-A does not publish guidelines for clocks/resets for shared IP. It is left to the platforms.
For Tegra platforms, the clocks/reset are managed by a central entity. TF-A is expected to co-ordinate with this entity. Unfortunately, PL011 does not fall in this category and is expected to be kept on by the previous bootloader.
-Varun
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Michal Simek via TF-A
Sent: Monday, June 21, 2021 2:24 PM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] PL011 clock handling between TF-A and Linux
External email: Use caution opening links or attachments
Hi,
recently we have hit the case where Linux has pl011 driver and using it as a console. The same console is also used by TF-A. If you look at implementation details Linux pl011 driver has in pl011_console_write() clk_enable/clk_disable calls.
I can't see any clock handling for PL011 in TF-A that's why I guess that TF-A expectation is that clocks are enabled and must be enabled all the time because pl011 is also used as crashed console.
That's why I would like to check with you what's the clock expectation in these shared IP cases.
Do you have a requirement that firmware should keep refcount of IP users and never disable clock when only one requires it?
Thanks,
Michal
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Hi,
recently we have hit the case where Linux has pl011 driver and using it
as a console. The same console is also used by TF-A. If you look at
implementation details Linux pl011 driver has in pl011_console_write()
clk_enable/clk_disable calls.
I can't see any clock handling for PL011 in TF-A that's why I guess that
TF-A expectation is that clocks are enabled and must be enabled all the
time because pl011 is also used as crashed console.
That's why I would like to check with you what's the clock expectation
in these shared IP cases.
Do you have a requirement that firmware should keep refcount of IP users
and never disable clock when only one requires it?
Thanks,
Michal
Hello tf experts,
I've been studying the PIE support in TF-A recently, and there is one thing
I'm confused about.
One is GOT table entry, is there any difference between this and .rela.dyn?
I have done some homework, but I didn't find the answer. If someone can
tell me, thanks a lot.
It looks like the current got segment is only 8 byte, so why must I need
this section? Which kind of code will put into this section?
Apologies we don't have any topics to present this week so I am cancelling the TF-A Tech forum for 17th June 2021.
We do however we have an exciting topic coming up for Thursday 1st July 2021 which we will share more about nearer the time.
In addition I’ll also like to promote this separate Linaro and Arm CCA Tech Event - Deep dive into Arm Confidential Compute Architecture the details of which can be found here https://www.linaro.org/events/linaro-and-arm-cca-tech-day-deep-dive-into-ar… Registration is free for this event which will begin at 14:00 UTC on June 23rd .
Thanks all.
Joanna
This event has been canceled with this note:
"Apologies we don't have any topics to present this week so I am cancelling
the Tech forum for 17th June 2021 however we have an exciting topic coming
up for Thursday 1st July 2021 which we will share near the time."
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
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here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
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Hello,
We (Nico/Raghu) have been implementing SEL0 partitions for Tegra platforms and recently hit an issue, where the "entrypoint-offset" field of the SP manifest [1] cannot cope with increasing manifest blobs. The way the SP manifest is created today, the "entrypoint-offset" field is set to a value *statically* by the implementer. Down the line if the manifest grows past the value written in the "entrypoint-offset", we must manually update it. This needs to be fixed.
We believe there is an opportunity to upgrade the sptool to handle this situation during SP package creation, where sptool calculates the manifest size and bumps the "entrypoint-offset" past the end of the manifest. There are other ways of patching the SP manifest at runtime, but they seem sub-optimal.
Please let me know if there are other ideas to solve this problem. I will post a patch to update the sptool shortly but wanted to get the ball rolling.
Cheers.
[1] 14. FF-A manifest binding to device tree - Trusted Firmware-A documentation<https://trustedfirmware-a.readthedocs.io/en/latest/components/ffa-manifest-…>
Hi Francois,
The blobs are passed in memory only when the primary core boots. The linear id is required when both primaries and secondaries boot.
Secondly, the linear id is used to reference per-cpu structures in memory during very early initialisation. Putting the linear id in a memory structure would either require a per-cpu structure (chicken and egg) or a read-only global structure (to avoid complicated locks with the MMU turned off).
It seems to me that the linear id should be passed in an unused register specified by the partition manifest.
Passing it in the blob list seems a bit counter intuitive to me but happy to understand your thoughts better.
cheers,
Achin
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 14 June 2021 16:29
To: Lukas Hanel <lukas.hanel(a)trustonic.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Support for Kinibi in ATF/SPMD - linear ID
This looks like a good candidate for the bloblist discussion we have on other mail thread.
Why not aggregating "topology" metadata in a block rather than passing "random" information elements in registers?
On Thu, 10 Jun 2021 at 13:57, Lukas Hanel via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
Hi,
in this PR, I propose a first change to the SPMD to better support Kinibi, the TEE from Trustonic.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/10235
The idea here is to pass the core linear id in the x3 register in the boot of secondary cores.
In the past, the Kinibi SPD was not public and so some requirements to TF-A were not visible to the wider community.
For Kinibi, one binary should run on a multitude of platforms.
For that reason, many platform-specific settings are shared by TF-A with Kinibi: at boot, in registers and in a boot datastructure, and at runtime.
In the line of work of making Kinibi compatible with FFA APIs, I moved some bits from the Kinibi SPD to the SPMD.
Instead of sharing such patches only with our customers, we would like to upstream the patches to the generic code.
For this particular patch, it is really simple and changes the interface SPMD-to-SPMC in a somewhat adhoc manner.
There is some discussion within ARM to standardize such behavior and to propose configuration options, i.e. within a manifest.
That way, you could change what register the linear id, if at all, should be transferred in.
A first tour of the CI showed that there seem to be no consequences to hafnium and optee.
I guess, question to the mailing list, is there something that this patch breaks?
Greetings,
Lukas
Trustonic SAS - 535 route de Lucioles, Les Aqueducs Batiment 2, Sophia Antipolis 06560 Valbonne, France – SAS au capital de 3 038 000€ - RCS Grasse – SIRET 480 011 998 00055 - TVA intracommunautaire : FR02 480 011 998
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--
[https://drive.google.com/a/linaro.org/uc?id=0BxTAygkus3RgQVhuNHMwUi1mYWc&ex…]
François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
T: +33.67221.6485
francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org> | Skype: ffozog
This looks like a good candidate for the bloblist discussion we have on
other mail thread.
Why not aggregating "topology" metadata in a block rather than passing
"random" information elements in registers?
On Thu, 10 Jun 2021 at 13:57, Lukas Hanel via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> Hi,
>
> in this PR, I propose a first change to the SPMD to better support Kinibi,
> the TEE from Trustonic.
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/10235
>
> The idea here is to pass the core linear id in the x3 register in the boot
> of secondary cores.
>
> In the past, the Kinibi SPD was not public and so some requirements to
> TF-A were not visible to the wider community.
> For Kinibi, one binary should run on a multitude of platforms.
> For that reason, many platform-specific settings are shared by TF-A with
> Kinibi: at boot, in registers and in a boot datastructure, and at runtime.
>
> In the line of work of making Kinibi compatible with FFA APIs, I moved
> some bits from the Kinibi SPD to the SPMD.
> Instead of sharing such patches only with our customers, we would like to
> upstream the patches to the generic code.
>
> For this particular patch, it is really simple and changes the interface
> SPMD-to-SPMC in a somewhat adhoc manner.
> There is some discussion within ARM to standardize such behavior and to
> propose configuration options, i.e. within a manifest.
> That way, you could change what register the linear id, if at all, should
> be transferred in.
>
> A first tour of the CI showed that there seem to be no consequences to
> hafnium and optee.
> I guess, question to the mailing list, is there something that this patch
> breaks?
>
> Greetings,
> Lukas
>
>
> Trustonic SAS - 535 route de Lucioles, Les Aqueducs Batiment 2, Sophia
> Antipolis 06560 Valbonne, France – SAS au capital de 3 038 000€ - RCS
> Grasse – SIRET 480 011 998 00055 - TVA intracommunautaire : FR02 480 011 998
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi,
in this PR, I propose a first change to the SPMD to better support Kinibi, the TEE from Trustonic.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/10235
The idea here is to pass the core linear id in the x3 register in the boot of secondary cores.
In the past, the Kinibi SPD was not public and so some requirements to TF-A were not visible to the wider community.
For Kinibi, one binary should run on a multitude of platforms.
For that reason, many platform-specific settings are shared by TF-A with Kinibi: at boot, in registers and in a boot datastructure, and at runtime.
In the line of work of making Kinibi compatible with FFA APIs, I moved some bits from the Kinibi SPD to the SPMD.
Instead of sharing such patches only with our customers, we would like to upstream the patches to the generic code.
For this particular patch, it is really simple and changes the interface SPMD-to-SPMC in a somewhat adhoc manner.
There is some discussion within ARM to standardize such behavior and to propose configuration options, i.e. within a manifest.
That way, you could change what register the linear id, if at all, should be transferred in.
A first tour of the CI showed that there seem to be no consequences to hafnium and optee.
I guess, question to the mailing list, is there something that this patch breaks?
Greetings,
Lukas
Trustonic SAS - 535 route de Lucioles, Les Aqueducs Batiment 2, Sophia Antipolis 06560 Valbonne, France - SAS au capital de 3 038 000EUR - RCS Grasse - SIRET 480 011 998 00055 - TVA intracommunautaire : FR02 480 011 998
Hi,
Can you try below steps, try with fresh pull?
1. Login with your github account on https://review.trustedfirmware.org/admin/repos/TF-A%2Ftrusted-firmware-a
2.
git clone "ssh://<user>@review.trustedfirmware.org:29418/TF-A/trusted-firmware-a
3. git push <remote-name> HEAD:refs/for/integration
4. While pushing if it complains about git hooks, run scp -p -P 29418 <user>@review.trustedfirmware.org:hooks/commit-msg "trusted-firmware-a/.git/hooks/" and amend your commit (it will give you this hint)
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Nicolas Boulenguez via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 03 April 2021 13:02
To: raghu.ncstate(a)icloud.com <raghu.ncstate(a)icloud.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; 'Benjamin Copeland' <ben.copeland(a)linaro.org>
Subject: Re: [TF-A] please fix incomplete distclean Makefile target
raghu.ncstate(a)icloud.com:
> Are you pushing ssh://<username>@review.trustedfirmware.org:29418/TF-A/trusted-firmware-a HEAD:refs/for/integration?
> Note that 29418 port. That tripped me up initially. It is not clear from your earlier emails where you cloned from(review.trustedfirmware.org or git.trustedfirmware.org).
[α] links to [β] which recommends
# git clone "https://review.trustedfirmware.org/TF-A/trusted-firmware-a"
I had an existing repository (most contributors probably do) and used
'git add remote' and 'git fetch' instead.
[α] recommends
# git push <remote-name> HEAD:refs/for/integration%<topic-branch>
As expected, the host requires a password.
# git push ssh://<user>@review.trustedfirmware.org:29418/TF-A/trusted-firmware-a HEAD:refs/for/integration?
-> fatal: invalid refspec 'HEAD:refs/for/integration?'
Anyhow, the host would require an SSH key.
[α] https://developer.trustedfirmware.org/w/tf_a/gerrit-getting-started/
[β] https://review.trustedfirmware.org/admin/repos/TF-A%2Ftrusted-firmware-a
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HI Hiren,
Can you please add more color to “even if I provide large enough string to hold the number, it does not print it”?
Are you saying that the library prints a partial value? If the calculation is off by 1, I assume, the library should at least print a partial value.
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Hiren Mehta via TF-A
Sent: Saturday, May 29, 2021 9:41 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] issue with vsnprintf() and unsigned_num_print()
External email: Use caution opening links or attachments
Hi All,
We are using the snprintf() (which uses vsnprintf() and unsigned_num_print()) from libc of ATF version 2.4
and running into an issue for printing a number into a string where even if I provide large enough string to hold the
number, it does not print it. I don't see that issue with it when I try to print a string using the same snprintf().
I understand that, as per the documentation use of snprintf is "banned or discouraged". But for the use case,
that we are using for, it is safe enough to use it assuming that it does it what it is supposed to do.
I am not sure if this is a known bug or what, but upon a further inspection, I found that there seems be a small bug
in the unsigned_num_print() for one of the 'if' condition given below which is causing the issue in terms of calculating
the available space in the string.
if (*chars_printed < n) {
.... do the prinring....
}
I believe it is supposed to be
if (*chars_printed <= n) { ----------------->> Notice '<=' instead of '<'
}
Any comment on whether this is on purpose or really a small bug?
The calling routine (vsnprintf) is already reducing 'n' by 1 for the terminating null character.
Thank you very much for your support.
-hiren
Hi
food for thought for tomorrow's call:
Passing information on what is plugged into the DIMM slots may not be as
straightforward as it sounds. You can plug pure DRAM, NVDIMMs or pure flash
(from Diablo technologies, acquired by RAMBus in 2019). The pure flash is a
module where there is a few MB as bounce buffers to flash located on the
DIMM itself. The largest element was 1TB on a single DIMM.
So passing a C structure that details the size of the DIMM fails to fully
describe NVDIMM and Flash on DIMM. Those two things required complex
Passing a DT fragment that describes the plugged module is generic and can
describe both the bounce buffers and the registers needed to access the
flash on DIMM. In the future you may find associative memory or whatever AI
based modules.
Bottom line, using DT fragment to describe memory is flexible for the three
existing cases and future proof.
The document shows that for a 2 DIMM representation and associated SPDs,
the additional cost is 88 bytes. 32 are fixed cost, 56 are somewhat name
size dependent and some related to FDT format.
There is no need for a full libfdt to actually produce that serialized data
on a hob.
So in my view, the benefit of having an alignment, version and evolution
proof structure that comes with DT fragment by far exceeds the cost of a
few bytes saved, even in the context of SRAM size.
Cheers
FF
On Wed, 2 Jun 2021 at 17:33, Joanna Farley via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> Hi All,
>
>
>
> The next TF-A Tech Forum is scheduled for Thu 3rd June 2021 16:00 – 17:00
> (BST).
>
>
>
> Agenda:
>
> - Discussion Session: Static and Dynamic Information Handling in TF-A
> (Session 2)
> - Lead by Manish Pandy and Madhukar Pappireddy
> - On tech forum this week, we would like to continue discussions on
> HOB list design.
> - The topics which we would like to cover is
> 1. Evaluate different proposals of passing information through
> boot phases.
> 2. If we don't get an agreement on one solution fit for all then
> we would try to get consensus for Infra segment platform(to solve original
> problem mentioned by Harb)
> 3. Try to get an agreement on size of tags and how "hybrid and
> tag only" HOB list can co-exist together?
>
>
>
>
>
> Thanks
>
>
>
> Joanna
>
>
>
>
> *You have been invited to the following event.* TF-A Tech Forum
>
> *more details »
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> We run an open technical forum call for anyone to participate and it is
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> the organiser and be added to the guest list, invite others regardless of
> their own invitation status or to modify your RSVP. Learn more
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>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
On Tue, 01 Jun 2021 14:34:05 +0100,
Dongjiu Geng <gengdongjiu1(a)gmail.com> wrote:
>
> Marc Zyngier <maz(a)kernel.org> 于2021年6月1日周二 下午6:09写道:
> >
> > On Tue, 01 Jun 2021 10:53:49 +0100,
> > Dongjiu Geng <gengdongjiu1(a)gmail.com> wrote:
> > >
> > > Mark Rutland <mark.rutland(a)arm.com> 于2021年6月1日周二 下午5:19写道:
> > > >
> > > > On Fri, May 28, 2021 at 05:26:51PM +0800, Dongjiu Geng wrote:
> > > > > Hi All,
> > > > > when Linux kernel boot from EL1, there is no method to let
> > > > > kernel to enter EL2 to enable hypervisor. so I want to add an SMC
> > > > > interface between kernel and EL3 ATF to let kernel can set the
> > > > > hypervisor vector table, then can enter EL2 to enable hypervisor, as
> > > > > shown in [1].
> > > > > Do you agree? Otherwise there is no method to enter EL2 hypervisor
> > > > > when kernel boot from EL1, because the hypervisor vector
> > > > > table(vbar_el2) is unknown.
> > > >
> > > > The kernel already supported being booted at EL2, where it will install
> > > > itself as the hypervisor (and will drop to EL1 if required). EL2 is the
> > > > preferred boot mode, as we document in:
> > > >
> > > > https://www.kernel.org/doc/html/latest/arm64/booting.html
> > > >
> > > > ... where we say:
> > > >
> > > > | The CPU must be in either EL2 (RECOMMENDED in order to have access to
> > > > | the virtualisation extensions) or non-secure EL1.
> > > >
> > > > We *strongly* prefer this over adding new ABIs to transition from EL1 to
> > > > EL2. Please boot the kernel at EL2 if you want to use KVM.
> > >
> > > Thanks for the answer.
> > > If use KVM, it should boot from EL2. But if the hypervisor is not
> > > KVM, such as Jailhouse hypervisor and some Chip manufacturer boot the
> > > host kernel from EL1(not follow above rule), it seems there is not way
> > > to enter the Jailhouse hypervisor.
> >
> > We only deal with two cases:
> > - either the kernel uses its own, built-in hypervisor: it boots at
> > EL2, and installs itself.
> >
> > - or there is a pre-existing hypervisor, and the kernel boots at EL1.
> >
> > In the past, Jailhouse used the exact same entry points as KVM. What
> > has changed?
>
> Jailhouse use the __hyp_stub_vectors vector table[1] in linux
> kernel arch/arm64/kernel/hyp-stub.S to re-set his own's hypervisor
> vector table, but if linux kernel is boot from EL1,it can not use the
> entry points(__hyp_stub_vectors). I agree Linux kernel is recommended
> boot from EL2, but some custer's boards not follow this rule.
So Jailhouse doesn't have this problem when used as intended.
>
> [1]:
> ENTRY(__hyp_stub_vectors)
> ventry el2_sync_invalid // Synchronous EL2t
> ventry el2_irq_invalid // IRQ EL2t
> ventry el2_fiq_invalid // FIQ EL2t
> ventry el2_error_invalid // Error EL2t
>
> ventry el2_sync_invalid // Synchronous EL2h
> ventry el2_irq_invalid // IRQ EL2h
> ventry el2_fiq_invalid // FIQ EL2h
> ventry el2_error_invalid // Error EL2h
>
> ventry el1_sync // Synchronous 64-bit EL1
> ventry el1_irq_invalid // IRQ 64-bit EL1
> ventry el1_fiq_invalid // FIQ 64-bit EL1
> ventry el1_error_invalid // Error 64-bit EL1
>
> ventry el1_sync_invalid // Synchronous 32-bit EL1
> ventry el1_irq_invalid // IRQ 32-bit EL1
> ventry el1_fiq_invalid // FIQ 32-bit EL1
> ventry el1_error_invalid // Error 32-bit EL1
> ENDPROC(__hyp_stub_vectors)
>
> >
> > Finally, if you can change the firmware to install the EL2 vectors,
> > you can also change it to enter the kernel at EL2. I suggest you do
> > that instead.
>
> I agree with you, but needs to change customer‘s board, I will try to
> discuess with customer.
In both cases, you'll need to change your customer's firmware.
It seems to me that there is no reason for the arm64 boot protocol to
change and adopt weird, wonderful and proprietary privilege escalation
methods.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
On Tue, 01 Jun 2021 10:53:49 +0100,
Dongjiu Geng <gengdongjiu1(a)gmail.com> wrote:
>
> Mark Rutland <mark.rutland(a)arm.com> 于2021年6月1日周二 下午5:19写道:
> >
> > On Fri, May 28, 2021 at 05:26:51PM +0800, Dongjiu Geng wrote:
> > > Hi All,
> > > when Linux kernel boot from EL1, there is no method to let
> > > kernel to enter EL2 to enable hypervisor. so I want to add an SMC
> > > interface between kernel and EL3 ATF to let kernel can set the
> > > hypervisor vector table, then can enter EL2 to enable hypervisor, as
> > > shown in [1].
> > > Do you agree? Otherwise there is no method to enter EL2 hypervisor
> > > when kernel boot from EL1, because the hypervisor vector
> > > table(vbar_el2) is unknown.
> >
> > The kernel already supported being booted at EL2, where it will install
> > itself as the hypervisor (and will drop to EL1 if required). EL2 is the
> > preferred boot mode, as we document in:
> >
> > https://www.kernel.org/doc/html/latest/arm64/booting.html
> >
> > ... where we say:
> >
> > | The CPU must be in either EL2 (RECOMMENDED in order to have access to
> > | the virtualisation extensions) or non-secure EL1.
> >
> > We *strongly* prefer this over adding new ABIs to transition from EL1 to
> > EL2. Please boot the kernel at EL2 if you want to use KVM.
>
> Thanks for the answer.
> If use KVM, it should boot from EL2. But if the hypervisor is not
> KVM, such as Jailhouse hypervisor and some Chip manufacturer boot the
> host kernel from EL1(not follow above rule), it seems there is not way
> to enter the Jailhouse hypervisor.
We only deal with two cases:
- either the kernel uses its own, built-in hypervisor: it boots at
EL2, and installs itself.
- or there is a pre-existing hypervisor, and the kernel boots at EL1.
In the past, Jailhouse used the exact same entry points as KVM. What
has changed?
Finally, if you can change the firmware to install the EL2 vectors,
you can also change it to enter the kernel at EL2. I suggest you do
that instead.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
On Fri, May 28, 2021 at 05:26:51PM +0800, Dongjiu Geng wrote:
> Hi All,
> when Linux kernel boot from EL1, there is no method to let
> kernel to enter EL2 to enable hypervisor. so I want to add an SMC
> interface between kernel and EL3 ATF to let kernel can set the
> hypervisor vector table, then can enter EL2 to enable hypervisor, as
> shown in [1].
> Do you agree? Otherwise there is no method to enter EL2 hypervisor
> when kernel boot from EL1, because the hypervisor vector
> table(vbar_el2) is unknown.
The kernel already supported being booted at EL2, where it will install
itself as the hypervisor (and will drop to EL1 if required). EL2 is the
preferred boot mode, as we document in:
https://www.kernel.org/doc/html/latest/arm64/booting.html
... where we say:
| The CPU must be in either EL2 (RECOMMENDED in order to have access to
| the virtualisation extensions) or non-secure EL1.
We *strongly* prefer this over adding new ABIs to transition from EL1 to
EL2. Please boot the kernel at EL2 if you want to use KVM.
Thanks,
Mark.
>
>
>
> [1]:
> el1_sync:
> cmp x0, #SMC_SET_VECTORS
> b.ne 2f
> msr vbar_el2, x1
> b 9f
>
> 2: cmp x0, #SMC_SOFT_RESTART
> b.ne 3f
> mov x0, x2
> mov x2, x4
> mov x4, x1
> mov x1, x3
> br x4 // no return
>
> 3: cmp x0, #SMC_RESET_VECTORS
> beq 9f // Nothing to reset!
>
> ldr x0, =SMC_STUB_ERR
> eret
>
> 9: mov x0, xzr
> eret
> ENDPROC(el1_sync)
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel(a)lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Hi All,
We are using the snprintf() (which uses vsnprintf() and unsigned_num_print()) from libc of ATF version 2.4and running into an issue for printing a number into a string where even if I provide large enough string to hold the number, it does not print it. I don't see that issue with it when I try to print a string using the same snprintf().I understand that, as per the documentation use of snprintf is "banned or discouraged". But for the use case,that we are using for, it is safe enough to use it assuming that it does it what it is supposed to do.
I am not sure if this is a known bug or what, but upon a further inspection, I found that there seems be a small bugin the unsigned_num_print() for one of the 'if' condition given below which is causing the issue in terms of calculatingthe available space in the string.
if (*chars_printed < n) {
.... do the prinring....}
I believe it is supposed to be
if (*chars_printed <= n) { ----------------->> Notice '<=' instead of '<' }
Any comment on whether this is on purpose or really a small bug?
The calling routine (vsnprintf) is already reducing 'n' by 1 for the terminating null character.
Thank you very much for your support.-hiren
On 4/19/21 11:11 AM, Jan Kiszka via TF-A wrote:
> On 19.04.21 17:21, Michal Simek wrote:
>> On 4/18/21 8:44 PM, Jan Kiszka wrote:
>>> when SPD or DEBUG is enabled, TF-A is moved to RAM on the zynqmp (as it
>>> longer fits into OCM). U-Boot happens to avoid that region, but the
>>> kernel's DTB has no reservation entry, and Linux will trigger an
>>> exception when accessing that region during early boot.
>>>
>>> Can we improve this - without requiring the user to manually add a
>>> reservation to the DTB? Should we unconditionally reserve
>>> 0x1000..0x7ffff in all BL33 DTBs? Or is there a chance to communicate
>>> that need? Or some way to detect in BL33 whether it is needed?
>>
>> Normally this ddr region should be also protected by security IPs that
>> NS has no access there.
>> It means in Xilinx flow this can be (and should be) propagated via
>> device-tree generator to final DTS file that you don't need to touch it
>> by hand.
>> I am not aware about any way that NS can query secure world what memory
>> can be used. And not sure if there is any standard way to do so.
>>
>
> OK, understood. But then, to be safe, shouldn't the upstream "static"
> default DT contain an exclusion of that region so that it won't get
> stuck if it is in use? Would block half a meg, but when you have a
> custom platform that does not need that, you can and will provide your
> own DT anyway.
Ideally, the static DTS is a description of the hardware only, and not
of runtime constraints imposed by the firmware. If BL31 needs to reserve
some memory, it can add that reservation to the DTB at runtime. The
fdt_add_reserved_memory() function is available for this purpose. For an
example, see the code used by the rpi4[0] or sun50i_h616[1] platforms.
If you later load a DTB from disk for use by Linux, you will need to
copy the reserved-memory nodes from the U-Boot DTB to the loaded DTB.
Regards,
Samuel
[0]:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/rpi/r…
[1]:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/allwi…
Hi,
The last time I checked injecting an SError from a higher to lower EL is a bad idea since the latter could be running with SErrors masked.
EL3 could check this before injecting but then there is no consistent contract with the lower EL about reporting of these errors. SDEI does not suffer from the same problem.
+James who knows more from the OS/Hypervisor perspective.
cheers,
Achin
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Soby Mathew via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 25 May 2021 09:59
To: Pali Rohár <pali(a)kernel.org>
Cc: kabel(a)kernel.org <kabel(a)kernel.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Rethrow SError from EL3 to kernel on arm64
[+tf-a list]
Hi Pali,
There are 2 philosophies for handing SError in the system, kernel first and firmware first. Assuming you want to stick with firmware first handling (i.e scr_el3.ea is set to 1), then as you mentioned, there are 2 ways to notify the kernel for delegating the error handling: SDEI and SError injection back to kernel. Upstream TF-A only supports SDEI at the moment.
For SError injection back to lower EL, you have to setup the hardware state via software at higher EL in such a way that it appears that the fault was taken to the exception vector at the lower exception level. The pseudocode function AArch64.TakeException() in ARM ARM shows the behavior when the PE takes an exception to an Exception level using AArch64 in Non-debug state. This behaviour has to replicated and it involves the higher EL setting up the PSTATE registers correctly and values in other registers for the lower EL (spsr, elr and fault syndrome registers) and jumping to the right offset point to by the vbar_elx of the lower EL. To the lower EL is appears as a SError has triggered at its exception vector and it can proceed with the fault handling.
Best Regards
Soby Mathew
> -----Original Message-----
> From: Pali Rohár <pali(a)kernel.org>
> Sent: Monday, May 24, 2021 6:07 PM
> To: Soby Mathew <Soby.Mathew(a)arm.com>
> Subject: Rethrow SError from EL3 to kernel on arm64
>
> Hello Soby!
>
> I have found following discussion in Armada 3720 PCIe SError issue:
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-
> a/+/1541/comment/ca882427_d142bde2/
>
> TF-A on Armada 3720 redirects all SErrors to EL3 and panic in TF-A handler.
> You wrote in that discussion:
>
> Ideally you need to signal the SError back to kernel from EL3 using
> SDEI or inject the SError to the lower EL and the kernel can decide to
> die or not.
>
> And I would like to ask you, could you help me with implementation of this
> SError rethrow functionality? Because I have absolutely no idea how to do it
> and catching all SErrors in EL3 is causing issues because some of them can be
> handled and recovered by kernel.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
[+tf-a list]
Hi Pali,
There are 2 philosophies for handing SError in the system, kernel first and firmware first. Assuming you want to stick with firmware first handling (i.e scr_el3.ea is set to 1), then as you mentioned, there are 2 ways to notify the kernel for delegating the error handling: SDEI and SError injection back to kernel. Upstream TF-A only supports SDEI at the moment.
For SError injection back to lower EL, you have to setup the hardware state via software at higher EL in such a way that it appears that the fault was taken to the exception vector at the lower exception level. The pseudocode function AArch64.TakeException() in ARM ARM shows the behavior when the PE takes an exception to an Exception level using AArch64 in Non-debug state. This behaviour has to replicated and it involves the higher EL setting up the PSTATE registers correctly and values in other registers for the lower EL (spsr, elr and fault syndrome registers) and jumping to the right offset point to by the vbar_elx of the lower EL. To the lower EL is appears as a SError has triggered at its exception vector and it can proceed with the fault handling.
Best Regards
Soby Mathew
> -----Original Message-----
> From: Pali Rohár <pali(a)kernel.org>
> Sent: Monday, May 24, 2021 6:07 PM
> To: Soby Mathew <Soby.Mathew(a)arm.com>
> Subject: Rethrow SError from EL3 to kernel on arm64
>
> Hello Soby!
>
> I have found following discussion in Armada 3720 PCIe SError issue:
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-
> a/+/1541/comment/ca882427_d142bde2/
>
> TF-A on Armada 3720 redirects all SErrors to EL3 and panic in TF-A handler.
> You wrote in that discussion:
>
> Ideally you need to signal the SError back to kernel from EL3 using
> SDEI or inject the SError to the lower EL and the kernel can decide to
> die or not.
>
> And I would like to ask you, could you help me with implementation of this
> SError rethrow functionality? Because I have absolutely no idea how to do it
> and catching all SErrors in EL3 is causing issues because some of them can be
> handled and recovered by kernel.
Thanks, Gary, and to everybody who contributed to this release!
I’d like to quickly remind everybody that, as part of the v2.5 release, the Trusted Firmware-A project formally adopted the Conventional Commits v1.0.0<https://www.conventionalcommits.org/en/v1.0.0/> specification to enable us to radically reduce our time-to-release in the future. Thank you to everybody who took part in the discussions that allowed us to integrate this, and to those whose concerns I hope we have by now satisfied.
As part of this effort, we have introduced a commit verification check to the existing Gerrit-triggered CI job. Where before this applied only to Arm employees, this now includes everybody (even you, reader of this email). This will no doubt require some initial mental reorientation as it did for our Arm-based guinea pigs, but I hope that this it will become a non-issue in short time.
To aid in the transition, we are also now packaging additional tooling, namely Commitizen<https://commitizen-tools.github.io/commitizen/> and commitlint<https://commitlint.js.org/#/>, to make writing conformant commits easier, the installation instructions for which have been integrated into the v2.5 prerequisites page<https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/prerequi…>. These tools are optional, but highly recommended if you do find your commits being rejected by the CI.
Please note that patches currently awaiting review on Gerrit will need to adhere to this specification before merging (this should only take a minute).
If you missed previous communications or are unfamiliar with Conventional Commits, here is a brief summary of the format that commit messages are now expected to take:
<type>[optional scope]: <description>
[optional body]
[optional footer(s)]
Where the <type> is one of:
* feat: A new feature
* fix: A bug fix
* docs: Documentation only changes
* style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
* refactor: A code change that neither fixes a bug nor adds a feature
* perf: A code change that improves performance
* test: Adding missing tests or correcting existing tests
* build: Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
* ci: Changes to our CI configuration files and scripts (example scopes: Travis, Circle, BrowserStack, SauceLabs)
* chore: Other changes that don't modify src or test files
* revert: Reverts a previous commit
And the [optional scope] consists of an optional parentheses-wrapped scope of your choosing, similarly to how many contributors prefixed their commits previously.
A real-world example:
docs(prerequisites): add `--no-save` to `npm install`
To avoid the mistake fixed by the previous commit, ensure users install
the Node.js dependencies without polluting the lock file by passing
`--no-save` to the `npm install` line.
Change-Id: I10b5cc17b9001fc2e26deee02bf99ce033a949c1
Signed-off-by: Chris Kay <chris.kay(a)arm.com>
If you have the time, please do read up on the specification for additional details – I promise it’s short.
So long, and happy committing. 😊
Regards,
Chris
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Gary Morrison via TF-A <tf-a(a)lists.trustedfirmware.org>
Date: Thursday, 20 May 2021 at 15:59
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Trusted Firmware version 2.5 is now available
Trusted Firmware version 2.5 is now available and can be found here:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tag/?h=v2.5https://git.trustedfirmware.org/TF-A/tf-a-tests.git/tag/?h=v2.5https://git.trustedfirmware.org/hafnium/hafnium.git/tag/?h=v2.5https://git.trustedfirmware.org/ci/tf-a-ci-scripts.git/tag/?h=v2.5
Please refer to the read-the-docs and change log for further information.
Regards,
Gary Morrison -- Arm
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hello Heiko,
Thanks for your patch!
TF-A project uses Gerrit as the review system for patches, would you
mind posting your patch there instead? More details about the patch
submission process can be found here:
https://trustedfirmware-a.readthedocs.io/en/latest/process/contributing.html
Regarding the patch itself, I agree with you that this feature would be
useful to other platforms as well. I wonder whether we need a new build
option for this, though. We already got LOG_LEVEL, which if set to 0,
will effectively silent any console output. However, it will still embed
the console driver code within the firmware, if I am not mistaken. So
perhaps we should change that, and make LOG_LEVEL=0 compile the console
driver code out, in addition to what it already does today.
How does that sound to you?
Regards,
Sandrine
On 5/18/21 4:01 PM, Heiko Schocher via TF-A wrote:
> when bootloaders and kernels console output is disabled,
> (called silent boot) no output on console is recommended.
>
> Add commandline option IMX_BOOT_SILENT to disable
> console registration at all.
>
> Default value is 0, so patch does not change current
> functionality.
>
> Signed-off-by: Heiko Schocher <hs(a)denx.de>
> ---
> I just added this to imx8mp, but may this option is
> useful on other platforms too?
>
> plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c | 4 ++++
> plat/imx/imx8m/imx8mp/platform.mk | 3 +++
> 2 files changed, 7 insertions(+)
>
> diff --git a/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c b/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c
> index 22fbd5e4b..d75143270 100644
> --- a/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c
> +++ b/plat/imx/imx8m/imx8mp/imx8mp_bl31_setup.c
> @@ -95,7 +95,9 @@ static void bl31_tzc380_setup(void)
> void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
> u_register_t arg2, u_register_t arg3)
> {
> +#if (IMX_BOOT_SILENT == 0)
> static console_t console;
> +#endif
> unsigned int i;
>
> /* Enable CSU NS access permission */
> @@ -109,10 +111,12 @@ void bl31_early_platform_setup2(u_register_t arg0, u_register_t arg1,
>
> imx8m_caam_init();
>
> +#if (IMX_BOOT_SILENT == 0)
> console_imx_uart_register(IMX_BOOT_UART_BASE, IMX_BOOT_UART_CLK_IN_HZ,
> IMX_CONSOLE_BAUDRATE, &console);
> /* This console is only used for boot stage */
> console_set_scope(&console, CONSOLE_FLAG_BOOT);
> +#endif
>
> /*
> * tell BL3-1 where the non-secure software image is located
> diff --git a/plat/imx/imx8m/imx8mp/platform.mk b/plat/imx/imx8m/imx8mp/platform.mk
> index 1d11e3df4..471c96e70 100644
> --- a/plat/imx/imx8m/imx8mp/platform.mk
> +++ b/plat/imx/imx8m/imx8mp/platform.mk
> @@ -54,3 +54,6 @@ $(eval $(call add_define,BL32_SIZE))
>
> IMX_BOOT_UART_BASE ?= 0x30890000
> $(eval $(call add_define,IMX_BOOT_UART_BASE))
> +
> +IMX_BOOT_SILENT ?= 0
> +$(eval $(call add_define,IMX_BOOT_SILENT))
>
Le mer. 19 mai 2021 à 03:58, Madhukar Pappireddy via TF-A <
tf-a(a)lists.trustedfirmware.org> a écrit :
> Hi,
>
> I tried to summarize the discussions in the previous TF-A tech forum
> regarding the proposal to adopt Hand-off Blocks (HOBs) for passing
> information along the boot chain. I am certain I could not capture all
> suggestions/concerns brought up during the call. I apologize if I missed
> and/or misinterpreted any comments and would appreciate it if everyone
> could share their thoughts in response to this email thread.
>
> The idea is to share information to other boot phases:
> > Dynamic information: Created during runtime. Shared in the form of a
> chain of blobs(built as a linked list of C structure objects i.e., HOB
> list).
> > Static information: Known at compile time. Historically, shared through
> the use of Device Tree/ACPI tables
>
> Both the above requirements are common in many ecosystems and need to
> co-exist.
>
> There are broadly 3 problems to solve:
> 1. Format of HOB structures: It looks like the consensus is that we could
> use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in
> u-boot).
> 2. Identification of HOB list entries: There is a debate about whether
> tags would suffice or if the HOB list producer and consumer would depend on
> UUID/GUIDs for identifying a specific HOB structure. Another suggestion was
> to use a hybrid approach. Reserve a single tag ID for
> identifying/constructing a HOB structure that further leverages UUID based
> identifier. This way, the generic HOB list doesn't need to support UUIDs
> and can work with tags.
> 3. The design contract for the static interface between two boot phases:
> The problem at hand is whether to pass a pointer to a HOB list or a device
> tree blob through the general-purpose registers for configuration hand-off
> between two boot phases. Some proposals that came up:
> > Proposal 1: Always pass a pointer to the device tree blob
> through the GP register and capture the pointer to the HOB list as a
> property of a node that is uniquely identifiable by the downstream boot
> phase. This needs to define a device tree binding such that producer and
> consumer agree on the information passed.
> > Proposal 2: Pass a pointer to a generic container through the GP
> register that can be interpreted appropriately by both boot loaders(i.e.,
> producer and consumer of the boot info). This container can either be a dtb
> or a HOB list which can be simply inferred by checking for a magic header
> that indicates if the buffer appears to be a flattened device tree.
> > One another concern that was brought up offline is to make sure
> we don't break current design contracts between various boot loader phases
> in TF-A. Many of the general-purpose registers have a designated purpose
> such as to share configurations between BL images( such as firmware config
> dtb, SoC config dtb, Non trusted firmware config dtb, memory layout, entry
> point info, etc.).
>
there should be another paragraph:
4. Requirements for data representation.
I’ll take two concrete examples related to DIMM slot population and
reporting.
6 years ago (can’t be sure) only DRAM modules could be fitted into DIMM
slots. And then came NVDIMM and flash as DIMM (invented by Diablo
technologies: 1TB of flash on a DIMM with a few MB as IO buffers and
control registers - those memory regions where the only addressable DRAM).
In both cases all firmware chain had to be changed to cope with them. If we
had used self descriptive information passing (CBOR, DT, AML) for DIMM slot
population and not C structure the journey would have been much simpler
with forward and backward compatibility as a major side effect.
So for data representation , I would concur with previous Ron Minnich
@googke comment that we should be using self descriptive information rather
than C structures.
>
> If I am not mistaken, a single design may not fit the needs of every
> segment(client, Infra, embedded) and the forum is open to solutions
> tailored for individual segments. Joanna will be sending a follow up email
> with more information about future TF-A tech forums that serves as a
> platform for further discussions.
>
> Thanks,
> Madhukar
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna
> Farley via TF-A
> Sent: Sunday, May 16, 2021 5:19 AM
> To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org
> >
> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot
> Architecture Mailman List <boot-architecture(a)lists.linaro.org>;
> tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>;
> Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <
> u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich
> <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for
> information passing between boot stages
>
> Apologies I failed with the recording. Manish/Madhu will reply early next
> week with the slides and some notes to help with a follow up session which
> we hope to hold this Thursday. Invite and agenda will also be sent out
> early next week.
>
> Thanks
>
> Joanna
>
> On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <
> tf-a-bounces(a)lists.trustedfirmware.org on behalf of
> tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi,
>
> Do we have slides and video from last week's discussion?
>
> Thanks,
> Okash
>
>
> On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
> <tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi Harb,
> >
> > Thanks for the idea. I am still not completely sure what benefit
> UUID provides to an open project. I'd like to propose something different,
> more in the spirit of open collaboration. I also worry that the word
> 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e.
> enabling/preferring closed-source firmware and the continued decline of
> open-source projects. It really should not be.
> >
> > So I suggest: Use simple integer IDs and reserve some area for
> 'private' use. If you want to collaborate across projects outside your
> company, you either need to allocate a 'public' ID or agree privately
> between the parties which private ID to use.
> >
> > This means that the default and easiest option is for collaboration
> and a public ID, with private ones (whose purpose may be secret) reserved
> just for private use.
> >
> > Regards,
> > Simon
> >
> > On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com> wrote:
> >>
> >> Hey Folks,
> >>
> >> We wanted to put out a middle-ground proposal to help guide the
> discussion on the call tomorrow.
> >>
> >>
> >>
> >> A proposal that we have been discussing offline involves reserving
> a single tag ID for the purpose of construction UEFI PI HOB List structure,
> and that tag would be used to identify a HOB-specific structure that does
> leverage UUID based identifier. This will eliminate the burden of having
> to support UUID as the tag, and this enables projects that require UUID
> based identifiers for the broad range of HOB structures that need to be
> produced during the booting of the platform. Once we have a tag for a HOB
> list, this will enable various HOB producers that can add/extend the HOB
> list in TF-A code (or even pre-TF-A code), with a HOB consumer for that
> UUID/GUID on the other side (i.e. whatever the BL33 image is booting on
> that platform).
> >>
> >>
> >>
> >> Essentially, the idea is if someone would like to support HOB
> structures in a standard way using TF-A, they would wrap it up in a
> BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we
> identify the structure as a HOB list is with this new reserved tag.
> >>
> >>
> >>
> >> Hopefully that makes sense and less contentious. Look forward to
> discuss this further on the call.
> >>
> >>
> >>
> >> Thanks,
> >>
> >> --Harb
> >>
> >>
> >>
> >> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
> >> Sent: Friday, April 30, 2021 8:14 AM
> >> To: François Ozog <francois.ozog(a)linaro.org>
> >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <
> jwerner(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org;
> U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <
> paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs)
> for information passing between boot stages
> >>
> >>
> >>
> >> Hi All,
> >>
> >>
> >>
> >> Please find invite for next TF-A Tech Forum session to continue our
> discussions on HOB implementation, feel free to forward it to others.
> >>
> >>
> >>
> >> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 –
> 17:00 (BST).
> >>
> >>
> >>
> >> Agenda:
> >>
> >> Discussion Session: Static and Dynamic Information Handling in TF-A
> >>
> >> Lead by Manish Pandey and Madhukar Pappireddy
> >>
> >> · There is ongoing mailing lists discussion[1] related with
> adopting a mechanism to pass information through boot stages.
> >>
> >> The requirement is two-fold:
> >>
> >> 1. Passing static information(config files)
> >>
> >> 2. Passing dynamic information (Hob list)
> >>
> >> In the upcoming TF-A tech forum, we can start with a discussion on
> dynamic information passing and if time permits, we can cover static
> information passing. The purpose of the call is to have an open discussion
> and continue the discussion from the trusted-substrate call[2] done
> earlier. We would like to understand the various requirements and possible
> ways to implement it in TF-A in a generalized way so that it can work with
> other Firmware projects.
> >>
> >>
> >>
> >> The two specific item which we would like to discuss are:
> >>
> >> 1. HOB format: TF-A/u-boot both has an existing bloblist
> implementation, which uses tag values. Question, can this be enhanced to
> use hybrid values(Tag and UUID) both?
> >>
> >> 2. Standardization on Physical register use to pass base of
> HoB data structure.
> >>
> >> References:
> >>
> >> [1]
> https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
> >>
> >> [2]
> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn…
> Passcode: IPn+5q%
> >>
> >>
> >>
> >> Thanks
> >>
> >>
> >>
> >> Joanna
> >>
> >>
> >>
> >> You have been invited to the following event.
> >>
> >> TF-A Tech Forum
> >>
> >> When
> >>
> >> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
> >>
> >> Calendar
> >>
> >> tf-a(a)lists.trustedfirmware.org
> >>
> >> Who
> >>
> >> •
> >>
> >> Bill Fletcher- creator
> >>
> >> •
> >>
> >> tf-a(a)lists.trustedfirmware.org
> >>
> >> more details »
> >>
> >>
> >>
> >> We run an open technical forum call for anyone to participate and
> it is not restricted to Trusted Firmware project members. It will operate
> under the guidance of the TF TSC.
> >>
> >>
> >>
> >> Feel free to forward this invite to colleagues. Invites are via the
> TF-A mailing list and also published on the Trusted Firmware website.
> Details are here:
> https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
> >>
> >>
> >>
> >> Trusted Firmware is inviting you to a scheduled Zoom meeting.
> >>
> >>
> >>
> >> Join Zoom Meeting
> >>
> >> https://zoom.us/j/9159704974
> >>
> >>
> >>
> >> Meeting ID: 915 970 4974
> >>
> >>
> >>
> >> One tap mobile
> >>
> >> +16465588656,,9159704974# US (New York)
> >>
> >> +16699009128,,9159704974# US (San Jose)
> >>
> >>
> >>
> >> Dial by your location
> >>
> >> +1 646 558 8656 US (New York)
> >>
> >> +1 669 900 9128 US (San Jose)
> >>
> >> 877 853 5247 US Toll-free
> >>
> >> 888 788 0099 US Toll-free
> >>
> >> Meeting ID: 915 970 4974
> >>
> >> Find your local number: https://zoom.us/u/ad27hc6t7h
> >>
> >>
> >>
> >> ________________________________
> >>
> >> From: François Ozog <francois.ozog(a)linaro.org>
> >> Sent: 08 April 2021 16:50
> >> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
> >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <
> jwerner(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <
> tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>;
> Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs)
> for information passing between boot stages
> >>
> >>
> >>
> >> Hi
> >>
> >>
> >>
> >> here is the meeting recording:
> >>
> >>
> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn…
> Passcode: IPn+5q%z
> >>
> >>
> >>
> >> I am really sorry about the confusion related to the meeting time.
> I have now understood: the Collaborate portal uses a specific calendar
> which is tied to US/Chicago timezone while the actual Google Calendar is
> tied to Central Europe timezone. I am going to drop the Collaborate portal
> and use a shared Google calendar (it should be visible on the
> trusted-substrate.org page).
> >>
> >>
> >>
> >> I'll try to summarize what I learnt and highlight my view on what
> can be next steps in a future mail.
> >>
> >>
> >>
> >> Cheers
> >>
> >>
> >>
> >> FF
> >>
> >>
> >>
> >> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
> >>
> >> Hi,
> >>
> >>
> >>
> >> From TF-A project point of view, we prefer to use existing
> mechanism to pass parameters across boot stages using linked list of tagged
> elements (as suggested by Julius). It has support for both generic and
> SiP-specific tags. Having said that, it does not stop partners to introduce
> new mechanisms suitable for their usecase in platform port initially and
> later move to generic code if its suitable for other platforms.
> >>
> >>
> >>
> >> To start with, Ampere can introduce a platform specific
> implementation of memory tag(speed/NUMA topology etc) which can be
> evaluated and discussed for generalization in future. The tag will be
> populated in BL2 stage and can be forwarded to further stages(and to BL33)
> by passing the head of list pointer in one of the registers. Initially any
> register can be used but going forward a standardization will be needed.
> >>
> >>
> >>
> >> The U-boot bloblist mentioned by Simon is conceptually similar to
> what TF-A is using, if there is consensus of using bloblist/taglist then
> TF-A tag list may be enhanced to take best of both the implementations.
> >>
> >>
> >>
> >> One of the potential problems of having structure used in different
> projects is maintainability, this can be avoided by having a single copy of
> these structures in TF-A (kept inside "include/export" which intended to be
> used by other projects.)
> >>
> >>
> >>
> >> Regarding usage of either UUID or tag, I echo the sentiments of
> Simon and Julius to keep it simple and use tag values.
> >>
> >>
> >>
> >> Looking forward to having further discussions on zoom call today.
> >>
> >>
> >>
> >> Thanks
> >>
> >> Manish P
> >>
> >>
> >>
> >> ________________________________
> >>
> >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
> Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
> >> Sent: 25 March 2021 02:43
> >> To: Simon Glass <sjg(a)chromium.org>
> >> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot
> Architecture Mailman List <boot-architecture(a)lists.linaro.org>;
> tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot
> Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>;
> Ron Minnich <rminnich(a)google.com>
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs)
> for information passing between boot stages
> >>
> >>
> >>
> >> Just want to point out that TF-A currently already supports a (very
> simple) mechanism like this:
> >>
> >>
> >>
> >>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> >>
> >>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> >>
> >>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> >>
> >>
> >>
> >> It's just a linked list of tagged elements. The tag space is split
> into TF-A-wide generic tags and SiP-specific tags (with plenty of room to
> spare if more areas need to be defined -- a 64-bit tag can fit a lot). This
> is currently being used by some platforms that run coreboot in place of
> BL1/BL2, to pass information from coreboot (BL2) to BL31.
> >>
> >>
> >>
> >> I would echo Simon's sentiment of keeping this as simple as
> possible and avoiding complicated and bloated data structures with UUIDs.
> You usually want to parse something like this as early as possible in the
> passed-to firmware stage, particularly if the structure encodes information
> about the debug console (like it does for the platforms I mentioned above).
> For example, in BL31 this basically means doing it right after moving from
> assembly to C in bl31_early_platform_setup2() to get the console up before
> running anything else. At that point in the BL31 initialization, the MMU
> and caches are disabled, so data accesses are pretty expensive and you
> don't want to spend a lot of parsing effort or calculate complicated
> checksums or the like. You just want something extremely simple where you
> ideally have to touch every data word only once.
> >>
> >>
> >>
> >> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
> >>
> >> Hi Harb,
> >>
> >>
> >>
> >> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com> wrote:
> >>
> >> Hello Folks,
> >>
> >> Appreciate the feedback and replies on this. Glad to see that
> there is interest in this topic.
> >>
> >>
> >>
> >> I try to address the comments/feedback from Francois and Simon
> below….
> >>
> >>
> >>
> >> @François Ozog – happy to discuss this on a zoom call. I will make
> that time slot work, and will be available to attend April 8, 4pm CT.
> >>
> >>
> >>
> >> Note that I’m using the term “HOB” here more generically, as there
> are typically vendor specific structures beyond the resource descriptor
> HOB, which provides only a small subset of the information that needs to be
> passed between the boot phases.
> >>
> >>
> >>
> >> The whole point here is to provide mechanism to develop firmware
> that we can build ARM Server SoC’s that support *any* BL33 payload (e.g.
> EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at
> some point). In other-words, we are trying to come up with a TF-A that
> would be completely agnostic to the implementation of BL33 (i.e. BL33 is
> built completely independently by a separate entity – e.g. an ODM/OEM).
> >>
> >>
> >>
> >> Keep in mind, in the server/datacenter market segment we are not
> building vertically integrated systems with a single entity compiling
> firmware/software stacks like most folks in TF-A have become use to. There
> are two categories of higher level firmware code blobs in the
> server/datacenter model:
> >>
> >> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2,
> BL31, and *possibly* one or more BL32 instances
> >> “Platform” or “board” firmware – in TF-A this may map to BL33 and
> *possibly* one or more BL32 instances.
> >>
> >>
> >>
> >> Even the platform firmware stack could be further fragmented by
> having multiple entities involved in delivering the entire firmware stack:
> IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
> >>
> >>
> >>
> >> To support a broad range of platform designs with a broad range of
> memory devices, we need a crisp and clear contract between the SoC firmware
> that initializes memory (e.g. BL2) and how that platform boot firmware
> (e.g. BL33) gathers information about what memory that was initialized, at
> what speeds, NUMA topology, and many other relevant information that needs
> to be known and comprehended by the platform firmware and eventually by the
> platform software.
> >>
> >>
> >>
> >> I understand the versatility of DT, but I see two major problems
> with DT:
> >>
> >> DT requires more complicated parsing to get properties, and even
> more complex to dynamically set properties – this HOB structures may need
> to be generated in boot phases where DDR is not available, and therefore we
> will be extremely memory constrained.
> >> DT is probably overkill for this purpose – We really just want a
> list of pointers to simple C structures that code cast (e.g. JEDEC SPD data
> blob)
> >>
> >>
> >>
> >> I think that we should not mix the efforts around DT/ACPI specs
> with what we are doing here, because those specs and concepts were
> developed for a completely different purpose (i.e. abstractions needed for
> OS / RTOS software, and not necessarily suitable for firmware-to-firmware
> hand-offs).
> >>
> >>
> >>
> >> Frankly, I would personally push back pretty hard on defining SMC’s
> for something that should be one way information passing. Every SMC we add
> is another attack vector to the secure world and an increased burden on the
> folks that have to do security auditing and threat analysis. I see no
> benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
> >>
> >>
> >>
> >> Please do let me know if you disagree and why. Look forward to
> discussing on this thread or on the call.
> >>
> >>
> >>
> >> @Simon Glass - Thanks for the pointer to bloblist. I briefly
> reviewed and it seems like a good baseline for what we may be looking for.
> >>
> >>
> >>
> >> That being said, I would say that there is some benefit in having
> some kind of unique identifiers (e.g. UUID or some unique signature) so
> that we can tie standardized data structures (based on some future TBD
> specs) to a particular ID. For example, if the TPM driver in BL33 is
> looking for the TPM structure in the HOB/BOB list, and may not care about
> the other data blobs. The driver needs a way to identify and locate the
> blob it cares about.
> >>
> >>
> >>
> >> The tag is intended to serve that purpose, although perhaps it
> should switch from an auto-allocating enum to one with explicit values for
> each entry and a range for 'local' use.
> >>
> >>
> >>
> >> I guess we can achieve this with the tag, but the problem with tag
> when you have eco-system with a lot of parties doing parallel development,
> you can end up with tag collisions and folks fighting about who has rights
> to what tag values. We would need some official process for folks to
> register tags for whatever new structures we define, or maybe some tag
> range for vendor specific structures. This comes with a lot of pain and
> bureaucracy. On the other hand, UUID has been a proven way to make it easy
> to just define your own blobs with *either* standard or vendor specific
> structures without worry of ID collisions between vendors.
> >>
> >>
> >>
> >> True. I think the pain is overstated, though. In this case I think
> we actually want something that can be shared between projects and orgs, so
> some amount of coordination could be considered a benefit. It could just be
> a github pull request. I find the UUID unfriendly and not just to code size
> and eyesight! Trying to discover what GUIDs mean or are valid is quite
> tricky. E.g. see this code:
> >>
> >>
> >>
> >> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
> >> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
> >> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
> >>
> >> (etc.)
> >>
> >>
> >>
> >> static struct guid_name {
> >> efi_guid_t guid;
> >> const char *name;
> >> } guid_name[] = {
> >> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
> >> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
> >> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
> >> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
> >> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
> >> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
> >> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
> >> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
> >>
> >> (never figured out what those two are)
> >>
> >>
> >> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
> >> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
> >> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
> >> { {}, "zero-guid" },
> >> {}
> >> };
> >>
> >> static const char *guid_to_name(const efi_guid_t *guid)
> >> {
> >> struct guid_name *entry;
> >>
> >> for (entry = guid_name; entry->name; entry++) {
> >> if (!guidcmp(guid, &entry->guid))
> >> return entry->name;
> >> }
> >>
> >> return NULL;
> >> }
> >>
> >>
> >>
> >> Believe it or not it took a fair bit of effort to find just that
> small list, with nearly every one in a separate doc, from memory.
> >>
> >>
> >>
> >>
> >>
> >> We can probably debate whether there is any value in GUID/UUID or
> not during the call… but again, boblist seems like a reasonable starting
> point as an alternative to HOB.
> >>
> >>
> >>
> >> Indeed. There is certainly value in both approaches.
> >>
> >>
> >>
> >> Regards,
> >>
> >> Simon
> >>
> >>
> >>
> >>
> >>
> >> Thanks,
> >>
> >> --Harb
> >>
> >>
> >>
> >> From: François Ozog <francois.ozog(a)linaro.org>
> >> Sent: Tuesday, March 23, 2021 10:00 AM
> >> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <
> rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
> >> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs)
> for information passing between boot stages
> >>
> >>
> >>
> >> +Ron Minnich +Paul Isaac's
> >>
> >>
> >>
> >> Adding Ron and Paul because I think this interface should be also
> benefiting LinuxBoot efforts.
> >>
> >>
> >>
> >> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
> >>
> >> Hi,
> >>
> >>
> >>
> >> I propose we cover the topic at the next Trusted Substrate zoom
> call on April 8th 4pm CET.
> >>
> >>
> >>
> >> The agenda:
> >>
> >> ABI between non-secure firmware and the rest of firmware (EL3,
> S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
> >>
> >> runtime conditions here relates to DRAM size and topology
> detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
> >>
> >>
> >>
> >> For additional background on existing metadata: UEFI Platform
> Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
> >>
> >> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
> >>
> >> This HOB lacks memory NUMA attachment or something that could be
> related to fill SRAT table for ACPI or relevant DT proximity domains.
> >>
> >> HOB is not consistent accros platforms: some platforms (Arm) lists
> memory from the booting NUMA node, other platforms (x86) lists all memory
> from all NUMA nodes. (At least this is the case on the two platforms I
> tested).
> >>
> >>
> >>
> >> There are two proposals to use memory structures from SPL/BLx up to
> the handover function (as defined in the Device Tree technical report)
> which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or
> EDK2.
> >>
> >> I would propose we also discuss possibility of FF-A interface to
> actually query information or request actions to be done (this is a model
> actually used in some SoCs with proprietary SMC calls).
> >>
> >>
> >>
> >> Requirements (to be validated):
> >>
> >> - ACPI and DT hardware descriptions.
> >>
> >> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
> >>
> >> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2,
> TF-A/LinuxBoot)
> >>
> >> - at least allows complete DRAM description and "persistent" usage
> (reserved areas for secure world or other usages)
> >>
> >> - support secure world device assignment
> >>
> >>
> >>
> >> Cheers
> >>
> >>
> >>
> >> FF
> >>
> >>
> >>
> >>
> >>
> >> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
> >>
> >> Hi,
> >>
> >> Can I suggest using bloblist for this instead? It is lightweight,
> >> easier to parse, doesn't have GUIDs and is already used within
> U-Boot
> >> for passing info between SPL/U-Boot, etc.
> >>
> >> Docs here:
> https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
> >> Header file describes the format:
> >> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
> >>
> >> Full set of unit tests:
> >> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
> >>
> >> Regards,
> >> Simon
> >>
> >> On Mon, 22 Mar 2021 at 23:58, François Ozog <
> francois.ozog(a)linaro.org> wrote:
> >> >
> >> > +Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>
> >> >
> >> > standardization is very much welcomed here and need to
> accommodate a very
> >> > diverse set of situations.
> >> > For example, TEE OS may need to pass memory reservations to BL33
> or
> >> > "capture" a device for the secure world.
> >> >
> >> > I have observed a number of architectures:
> >> > 1) pass information from BLx to BLy in the form of a specific
> object
> >> > 2) BLx called by BLy by a platform specific SMC to get information
> >> > 3) BLx called by BLy by a platform specific SMC to perform Device
> Tree
> >> > fixups
> >> >
> >> > I also imagined a standardized "broadcast" FF-A call so that any
> firmware
> >> > element can either provide information or "do something".
> >> >
> >> > My understanding of your proposal is about standardizing on
> architecture 1)
> >> > with the HOB format.
> >> >
> >> > The advantage of the HOB is simplicity but it may be difficult to
> implement
> >> > schemes such as pruning a DT because device assignment in the
> secure world.
> >> >
> >> > In any case, it looks feasible to have TF-A and OP-TEE complement
> the list
> >> > of HOBs to pass information downstream (the bootflow).
> >> >
> >> > It would be good to start with building the comprehensive list of
> >> > information that need to be conveyed between firmware elements:
> >> >
> >> > information. | authoritative entity | reporting entity |
> information
> >> > exchanged:
> >> > dram | TFA | TFA
> |
> >> > <format to be detailed, NUMA topology to build the SRAT table or
> DT
> >> > equivalent?>
> >> > PSCI | SCP | TFA?
> |
> >> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
> >> > secure SRAM | TFA. | TFA. |
> >> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
> >> > other? | |
> >> > |
> >> >
> >> > Cheers
> >> >
> >> > FF
> >> >
> >> >
> >> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
> >> > tf-a(a)lists.trustedfirmware.org> wrote:
> >> >
> >> > > Hello Folks,
> >> > >
> >> > >
> >> > >
> >> > > I'm emailing to start an open discussion about the adoption of
> a concept
> >> > > known as "hand-off blocks" or HOB to become a part of the TF-A
> Firmware
> >> > > Framework Architecture (FFA). This is something that is a
> pretty major
> >> > > pain point when it comes to the adoption of TF-A in ARM Server
> SoC’s
> >> > > designed to enable a broad range of highly configurable
> datacenter
> >> > > platforms.
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > What is a HOB (Background)?
> >> > >
> >> > > ---------------------------
> >> > >
> >> > > UEFI PI spec describes a particular definition for how HOB may
> be used for
> >> > > transitioning between the PEI and DXE boot phases, which is a
> good
> >> > > reference point for this discussion, but not necessarily the
> exact solution
> >> > > appropriate for TF-A.
> >> > >
> >> > >
> >> > >
> >> > > A HOB is simply a dynamically generated data structure passed
> in between
> >> > > two boot phases. This is information that was obtained through
> discovery
> >> > > and needs to be passed forward to the next boot phase *once*,
> with no API
> >> > > needed to call back (e.g. no call back into previous firmware
> phase is
> >> > > needed to fetch this information at run-time - it is simply
> passed one time
> >> > > during boot).
> >> > >
> >> > >
> >> > >
> >> > > There may be one or more HOBs passed in between boot phases.
> If there are
> >> > > more than one HOB that needs to be passed, this can be in a
> form of a "HOB
> >> > > table", which (for example) could be a UUID indexed array of
> pointers to
> >> > > HOB structures, used to locate a HOB of interest (based on
> UUID). In such
> >> > > cases, instead of passing a single HOB, the boot phases may
> rely on passing
> >> > > the pointer to the HOB table.
> >> > >
> >> > >
> >> > >
> >> > > This has been extremely useful concept to employ on highly
> configurable
> >> > > systems that must rely on flexible discovery mechanisms to
> initialize and
> >> > > boot the system. This is especially helpful when you have
> multiple
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > Why do we need HOBs in TF-A?:
> >> > >
> >> > > -----------------------------
> >> > >
> >> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM
> Server SoC in
> >> > > a way that is SoC specific *but* platform agnostic. This means
> that a
> >> > > single ARM SoC that a SiP may deliver to customers may provide
> a single
> >> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support
> a broad
> >> > > range of platform designs and configurations in order to boot a
> platform
> >> > > specific firmware (e.g. BL33 and possibly even BL32 code). In
> order to
> >> > > achieve this, the platform configuration must be *discovered*
> instead of
> >> > > statically compiled as it is today in TF-A via device tree based
> >> > > enumeration. The mechanisms of discovery may differ broadly
> depending on
> >> > > the relevant industry standard, or in some cases may have rely
> on SiP
> >> > > specific discovery flows.
> >> > >
> >> > >
> >> > >
> >> > > For example: On server systems that support a broad range DIMM
> memory
> >> > > population/topologies, all the necessary information required
> to boot is
> >> > > fully discovered via standard JEDEC Serial Presence Detect
> (SPD) over an
> >> > > I2C bus. Leveraging the SPD bus, may platform variants could
> be supported
> >> > > with a single TF-A binary. Not only is this information
> required to
> >> > > initialize memory in early boot phases (e.g. BL2), the
> subsequent boot
> >> > > phases will also need this SPD info to construct a system
> physical address
> >> > > map and properly initialize the MMU based on the memory
> present, and where
> >> > > the memory may be present. Subsequent boot phases (e.g. BL33 /
> UEFI) may
> >> > > need to generate standard firmware tables to the operating
> systems, such as
> >> > > SMBIOS tables describing DIMM topology and various ACPI tables
> (e.g. SLIT,
> >> > > SRAT, even NFIT if NVDIMM's are present).
> >> > >
> >> > >
> >> > >
> >> > > In short, it all starts with a standardized or vendor specific
> discovery
> >> > > flow in an early boot stage (e.g. BL1/BL2), followed by the
> passing of
> >> > > information to the next boot stages (e.g. BL31/BL32/BL33).
> >> > >
> >> > >
> >> > >
> >> > > Today, every HOB may be a vendor specific structure, but in the
> future
> >> > > there may be benefit of defining standard HOBs. This may be
> useful for
> >> > > memory discovery, passing the system physical address map,
> enabling TPM
> >> > > measured boot, and potentially many other common HOB use-cases.
> >> > >
> >> > >
> >> > >
> >> > > It would be extremely beneficial to the datacenter market
> segment if the
> >> > > TF-A community would adopt this concept of information passing
> between all
> >> > > boot phases as opposed to rely solely on device tree
> enumeration. This is
> >> > > not intended to replace device tree, rather intended as an
> alternative way
> >> > > to describe the info that must be discovered and dynamically
> generated.
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > Conclusion:
> >> > >
> >> > > -----------
> >> > >
> >> > > We are proposing that the TF-A community begin pursuing the
> adoption of
> >> > > HOBs as a mechanism used for information exchange between each
> boot stage
> >> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer
> term we
> >> > > want to explore standardizing some HOB structures for the BL33
> phase (e.g.
> >> > > UEFI HOB structures), but initially would like to agree on this
> being a
> >> > > useful mechanism used to pass information between each boot
> stage.
> >> > >
> >> > >
> >> > >
> >> > > Thanks,
> >> > >
> >> > > --Harb
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > --
> >> > > TF-A mailing list
> >> > > TF-A(a)lists.trustedfirmware.org
> >> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >> > >
> >> >
> >> >
> >> > --
> >> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing
> Group*
> >> > T: +33.67221.6485
> >> > francois.ozog(a)linaro.org | Skype: ffozog
> >> > _______________________________________________
> >> > boot-architecture mailing list
> >> > boot-architecture(a)lists.linaro.org
> >> > https://lists.linaro.org/mailman/listinfo/boot-architecture
> >>
> >>
> >>
> >>
> >> --
> >>
> >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> >>
> >> T: +33.67221.6485
> >> francois.ozog(a)linaro.org | Skype: ffozog
> >>
> >>
> >>
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >>
> >>
> >>
> >>
> >> --
> >>
> >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> >>
> >> T: +33.67221.6485
> >> francois.ozog(a)linaro.org | Skype: ffozog
> >>
> >>
> >>
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >>
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >>
> >>
> >>
> >>
> >> --
> >>
> >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> >>
> >> T: +33.67221.6485
> >> francois.ozog(a)linaro.org | Skype: ffozog
> >>
> >>
> >
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Le mer. 19 mai 2021 à 23:51, Jeremy Linton via TF-A <
tf-a(a)lists.trustedfirmware.org> a écrit :
> On 5/18/21 8:59 PM, Madhukar Pappireddy via TF-A wrote:
> > Hi,
> >
> > I tried to summarize the discussions in the previous TF-A tech forum
> regarding the proposal to adopt Hand-off Blocks (HOBs) for passing
> information along the boot chain. I am certain I could not capture all
> suggestions/concerns brought up during the call. I apologize if I missed
> and/or misinterpreted any comments and would appreciate it if everyone
> could share their thoughts in response to this email thread.
> >
> > The idea is to share information to other boot phases:
> >> Dynamic information: Created during runtime. Shared in the form of a
> chain of blobs(built as a linked list of C structure objects i.e., HOB
> list).
> >> Static information: Known at compile time. Historically, shared through
> the use of Device Tree/ACPI tables
> >
> > Both the above requirements are common in many ecosystems and need to
> co-exist.
> >
> > There are broadly 3 problems to solve:
> > 1. Format of HOB structures: It looks like the consensus is that we
> could use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in
> u-boot).
> > 2. Identification of HOB list entries: There is a debate about whether
> tags would suffice or if the HOB list producer and consumer would depend on
> UUID/GUIDs for identifying a specific HOB structure. Another suggestion was
> to use a hybrid approach. Reserve a single tag ID for
> identifying/constructing a HOB structure that further leverages UUID based
> identifier. This way, the generic HOB list doesn't need to support UUIDs
> and can work with tags.
> > 3. The design contract for the static interface between two boot phases:
> The problem at hand is whether to pass a pointer to a HOB list or a device
> tree blob through the general-purpose registers for configuration hand-off
> between two boot phases. Some proposals that came up:
> > > Proposal 1: Always pass a pointer to the device tree blob
> through the GP register and capture the pointer to the HOB list as a
> property of a node that is uniquely identifiable by the downstream boot
> phase. This needs to define a device tree binding such that producer and
> consumer agree on the information passed.
>
>
> Using DT to pass platform info at this level is sort of crazy on an ACPI
> machine which won't have native DTs. Meaning there is an additional
> level of unnecessary indirection that needs to be converted back into a
> format which can be utilized by AML and other parts of the ACPI stack.
I would love the BL33 becomes a product maker (using a board vendor
product) decision: using EDK2, U-Boot, LinuxBoot or even Xen directly as
BL33.
If this is a goal , then there will be a need for a translation layer
between the firmware framework (tfa, core boot, uboot SPL) formats and the
non secure firmware format.
If this is not a goal then I agree that passing a DT in an ACPI system is
suboptimal. That said there is a UEFI PI HOB that is a DT container and
used in existing systems. And conversely, in systems with complex MDIO or
other hardware without ACPI representation (serdes), it does not make sense
to bring ACPI stuff.
The easiest path is to not give a choice of BL33 and have a format for each
“realm”: DT or ACPI.
>
> Its also helpful to look at what has become of the rpi4 uefi port, where
> the DT is actually dynamic (or provided by the user, complete with HAT
> overlays) and fed into the lower level firmware and propagated up
> through the system. The result has frequently been subtle bugs or boot
> failures because the DT provided by the rpi foundation as part of their
> low level firwmare+kernel stack is modified by their low level firwmare,
> and it differs from the DT in mainline linux. So more than once we have
> discovered that there isn't a single DT that can be boot both the
> current firmware and a current mainline linux. In the past there was
> even an option to use one DT for the firmware and an entirely seperate
> one for linux, but that was removed when it bacame apparent you couldn't
> have the lower level firmwaer say modifying MMIO windows for the PCIe
> subsystem and not propogate that into the other user supplied DT.
>
ACPI shows that firmware provided hardware description makes life easier.
That’s why Arm SystemReady-IR states that it should be the case for DT too.
RPI4 and beaglebone have had different strategies and each with good and
bad things. The Linaro Device Tree Evolution open project is tackling
diverse aspects of DT including proper handling hats, and other runtime
adaptations.
>
> At this point the uefi firmware on the rpi will provide a DT if asked,
> but it doesn't parse it nor does anything in the AML. Instead everything
> is done directly against the hardware, even when the HW registers aren't
> well documented.That is in large parts because the AML requirements are
> a lot different than what is provided in the DT.
>
>
>
> > > Proposal 2: Pass a pointer to a generic container through the GP
> register that can be interpreted appropriately by both boot loaders(i.e.,
> producer and consumer of the boot info). This container can either be a dtb
> or a HOB list which can be simply inferred by checking for a magic header
> that indicates if the buffer appears to be a flattened device tree.
> > > One another concern that was brought up offline is to make sure
> we don't break current design contracts between various boot loader phases
> in TF-A. Many of the general-purpose registers have a designated purpose
> such as to share configurations between BL images( such as firmware config
> dtb, SoC config dtb, Non trusted firmware config dtb, memory layout, entry
> point info, etc.).
> >
> > If I am not mistaken, a single design may not fit the needs of every
> segment(client, Infra, embedded) and the forum is open to solutions
> tailored for individual segments. Joanna will be sending a follow up email
> with more information about future TF-A tech forums that serves as a
> platform for further discussions.
> >
> > Thanks,
> > Madhukar
> >
> > -----Original Message-----
> > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna
> Farley via TF-A
> > Sent: Sunday, May 16, 2021 5:19 AM
> > To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <
> sjg(a)chromium.org>
> > Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot
> Architecture Mailman List <boot-architecture(a)lists.linaro.org>;
> tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>;
> Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <
> u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich
> <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
> > Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for
> information passing between boot stages
> >
> > Apologies I failed with the recording. Manish/Madhu will reply early
> next week with the slides and some notes to help with a follow up session
> which we hope to hold this Thursday. Invite and agenda will also be sent
> out early next week.
> >
> > Thanks
> >
> > Joanna
> >
> > On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <
> tf-a-bounces(a)lists.trustedfirmware.org on behalf of
> tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi,
> >
> > Do we have slides and video from last week's discussion?
> >
> > Thanks,
> > Okash
> >
> >
> > On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
> > <tf-a(a)lists.trustedfirmware.org> wrote:
> > >
> > > Hi Harb,
> > >
> > > Thanks for the idea. I am still not completely sure what benefit
> UUID provides to an open project. I'd like to propose something different,
> more in the spirit of open collaboration. I also worry that the word
> 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e.
> enabling/preferring closed-source firmware and the continued decline of
> open-source projects. It really should not be.
> > >
> > > So I suggest: Use simple integer IDs and reserve some area for
> 'private' use. If you want to collaborate across projects outside your
> company, you either need to allocate a 'public' ID or agree privately
> between the parties which private ID to use.
> > >
> > > This means that the default and easiest option is for
> collaboration and a public ID, with private ones (whose purpose may be
> secret) reserved just for private use.
> > >
> > > Regards,
> > > Simon
> > >
> > > On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com> wrote:
> > >>
> > >> Hey Folks,
> > >>
> > >> We wanted to put out a middle-ground proposal to help guide the
> discussion on the call tomorrow.
> > >>
> > >>
> > >>
> > >> A proposal that we have been discussing offline involves
> reserving a single tag ID for the purpose of construction UEFI PI HOB List
> structure, and that tag would be used to identify a HOB-specific structure
> that does leverage UUID based identifier. This will eliminate the burden
> of having to support UUID as the tag, and this enables projects that
> require UUID based identifiers for the broad range of HOB structures that
> need to be produced during the booting of the platform. Once we have a tag
> for a HOB list, this will enable various HOB producers that can add/extend
> the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for
> that UUID/GUID on the other side (i.e. whatever the BL33 image is booting
> on that platform).
> > >>
> > >>
> > >>
> > >> Essentially, the idea is if someone would like to support HOB
> structures in a standard way using TF-A, they would wrap it up in a
> BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we
> identify the structure as a HOB list is with this new reserved tag.
> > >>
> > >>
> > >>
> > >> Hopefully that makes sense and less contentious. Look forward
> to discuss this further on the call.
> > >>
> > >>
> > >>
> > >> Thanks,
> > >>
> > >> --Harb
> > >>
> > >>
> > >>
> > >> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
> > >> Sent: Friday, April 30, 2021 8:14 AM
> > >> To: François Ozog <francois.ozog(a)linaro.org>
> > >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <
> jwerner(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org;
> U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <
> paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> > >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
> (HOBs) for information passing between boot stages
> > >>
> > >>
> > >>
> > >> Hi All,
> > >>
> > >>
> > >>
> > >> Please find invite for next TF-A Tech Forum session to continue
> our discussions on HOB implementation, feel free to forward it to others.
> > >>
> > >>
> > >>
> > >> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00
> – 17:00 (BST).
> > >>
> > >>
> > >>
> > >> Agenda:
> > >>
> > >> Discussion Session: Static and Dynamic Information Handling in
> TF-A
> > >>
> > >> Lead by Manish Pandey and Madhukar Pappireddy
> > >>
> > >> · There is ongoing mailing lists discussion[1] related
> with adopting a mechanism to pass information through boot stages.
> > >>
> > >> The requirement is two-fold:
> > >>
> > >> 1. Passing static information(config files)
> > >>
> > >> 2. Passing dynamic information (Hob list)
> > >>
> > >> In the upcoming TF-A tech forum, we can start with a discussion
> on dynamic information passing and if time permits, we can cover static
> information passing. The purpose of the call is to have an open discussion
> and continue the discussion from the trusted-substrate call[2] done
> earlier. We would like to understand the various requirements and possible
> ways to implement it in TF-A in a generalized way so that it can work with
> other Firmware projects.
> > >>
> > >>
> > >>
> > >> The two specific item which we would like to discuss are:
> > >>
> > >> 1. HOB format: TF-A/u-boot both has an existing bloblist
> implementation, which uses tag values. Question, can this be enhanced to
> use hybrid values(Tag and UUID) both?
> > >>
> > >> 2. Standardization on Physical register use to pass base of
> HoB data structure.
> > >>
> > >> References:
> > >>
> > >> [1]
> https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
> > >>
> > >> [2]
> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn…
> Passcode: IPn+5q%
> > >>
> > >>
> > >>
> > >> Thanks
> > >>
> > >>
> > >>
> > >> Joanna
> > >>
> > >>
> > >>
> > >> You have been invited to the following event.
> > >>
> > >> TF-A Tech Forum
> > >>
> > >> When
> > >>
> > >> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
> > >>
> > >> Calendar
> > >>
> > >> tf-a(a)lists.trustedfirmware.org
> > >>
> > >> Who
> > >>
> > >> •
> > >>
> > >> Bill Fletcher- creator
> > >>
> > >> •
> > >>
> > >> tf-a(a)lists.trustedfirmware.org
> > >>
> > >> more details »
> > >>
> > >>
> > >>
> > >> We run an open technical forum call for anyone to participate
> and it is not restricted to Trusted Firmware project members. It will
> operate under the guidance of the TF TSC.
> > >>
> > >>
> > >>
> > >> Feel free to forward this invite to colleagues. Invites are via
> the TF-A mailing list and also published on the Trusted Firmware website.
> Details are here:
> https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
> > >>
> > >>
> > >>
> > >> Trusted Firmware is inviting you to a scheduled Zoom meeting.
> > >>
> > >>
> > >>
> > >> Join Zoom Meeting
> > >>
> > >> https://zoom.us/j/9159704974
> > >>
> > >>
> > >>
> > >> Meeting ID: 915 970 4974
> > >>
> > >>
> > >>
> > >> One tap mobile
> > >>
> > >> +16465588656,,9159704974# US (New York)
> > >>
> > >> +16699009128,,9159704974# US (San Jose)
> > >>
> > >>
> > >>
> > >> Dial by your location
> > >>
> > >> +1 646 558 8656 US (New York)
> > >>
> > >> +1 669 900 9128 US (San Jose)
> > >>
> > >> 877 853 5247 US Toll-free
> > >>
> > >> 888 788 0099 US Toll-free
> > >>
> > >> Meeting ID: 915 970 4974
> > >>
> > >> Find your local number: https://zoom.us/u/ad27hc6t7h
> > >>
> > >>
> > >>
> > >> ________________________________
> > >>
> > >> From: François Ozog <francois.ozog(a)linaro.org>
> > >> Sent: 08 April 2021 16:50
> > >> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
> > >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <
> jwerner(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <
> tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>;
> Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> > >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
> (HOBs) for information passing between boot stages
> > >>
> > >>
> > >>
> > >> Hi
> > >>
> > >>
> > >>
> > >> here is the meeting recording:
> > >>
> > >>
> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn…
> Passcode: IPn+5q%z
> > >>
> > >>
> > >>
> > >> I am really sorry about the confusion related to the meeting
> time. I have now understood: the Collaborate portal uses a specific
> calendar which is tied to US/Chicago timezone while the actual Google
> Calendar is tied to Central Europe timezone. I am going to drop the
> Collaborate portal and use a shared Google calendar (it should be visible
> on the trusted-substrate.org page).
> > >>
> > >>
> > >>
> > >> I'll try to summarize what I learnt and highlight my view on
> what can be next steps in a future mail.
> > >>
> > >>
> > >>
> > >> Cheers
> > >>
> > >>
> > >>
> > >> FF
> > >>
> > >>
> > >>
> > >> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
> > >>
> > >> Hi,
> > >>
> > >>
> > >>
> > >> From TF-A project point of view, we prefer to use existing
> mechanism to pass parameters across boot stages using linked list of tagged
> elements (as suggested by Julius). It has support for both generic and
> SiP-specific tags. Having said that, it does not stop partners to introduce
> new mechanisms suitable for their usecase in platform port initially and
> later move to generic code if its suitable for other platforms.
> > >>
> > >>
> > >>
> > >> To start with, Ampere can introduce a platform specific
> implementation of memory tag(speed/NUMA topology etc) which can be
> evaluated and discussed for generalization in future. The tag will be
> populated in BL2 stage and can be forwarded to further stages(and to BL33)
> by passing the head of list pointer in one of the registers. Initially any
> register can be used but going forward a standardization will be needed.
> > >>
> > >>
> > >>
> > >> The U-boot bloblist mentioned by Simon is conceptually similar
> to what TF-A is using, if there is consensus of using bloblist/taglist
> then TF-A tag list may be enhanced to take best of both the implementations.
> > >>
> > >>
> > >>
> > >> One of the potential problems of having structure used in
> different projects is maintainability, this can be avoided by having a
> single copy of these structures in TF-A (kept inside "include/export" which
> intended to be used by other projects.)
> > >>
> > >>
> > >>
> > >> Regarding usage of either UUID or tag, I echo the sentiments of
> Simon and Julius to keep it simple and use tag values.
> > >>
> > >>
> > >>
> > >> Looking forward to having further discussions on zoom call today.
> > >>
> > >>
> > >>
> > >> Thanks
> > >>
> > >> Manish P
> > >>
> > >>
> > >>
> > >> ________________________________
> > >>
> > >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf
> of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
> > >> Sent: 25 March 2021 02:43
> > >> To: Simon Glass <sjg(a)chromium.org>
> > >> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>;
> Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>;
> tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot
> Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>;
> Ron Minnich <rminnich(a)google.com>
> > >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
> (HOBs) for information passing between boot stages
> > >>
> > >>
> > >>
> > >> Just want to point out that TF-A currently already supports a
> (very simple) mechanism like this:
> > >>
> > >>
> > >>
> > >>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> > >>
> > >>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> > >>
> > >>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> > >>
> > >>
> > >>
> > >> It's just a linked list of tagged elements. The tag space is
> split into TF-A-wide generic tags and SiP-specific tags (with plenty of
> room to spare if more areas need to be defined -- a 64-bit tag can fit a
> lot). This is currently being used by some platforms that run coreboot in
> place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
> > >>
> > >>
> > >>
> > >> I would echo Simon's sentiment of keeping this as simple as
> possible and avoiding complicated and bloated data structures with UUIDs.
> You usually want to parse something like this as early as possible in the
> passed-to firmware stage, particularly if the structure encodes information
> about the debug console (like it does for the platforms I mentioned above).
> For example, in BL31 this basically means doing it right after moving from
> assembly to C in bl31_early_platform_setup2() to get the console up before
> running anything else. At that point in the BL31 initialization, the MMU
> and caches are disabled, so data accesses are pretty expensive and you
> don't want to spend a lot of parsing effort or calculate complicated
> checksums or the like. You just want something extremely simple where you
> ideally have to touch every data word only once.
> > >>
> > >>
> > >>
> > >> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
> > >>
> > >> Hi Harb,
> > >>
> > >>
> > >>
> > >> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com> wrote:
> > >>
> > >> Hello Folks,
> > >>
> > >> Appreciate the feedback and replies on this. Glad to see that
> there is interest in this topic.
> > >>
> > >>
> > >>
> > >> I try to address the comments/feedback from Francois and Simon
> below….
> > >>
> > >>
> > >>
> > >> @François Ozog – happy to discuss this on a zoom call. I will
> make that time slot work, and will be available to attend April 8, 4pm CT.
> > >>
> > >>
> > >>
> > >> Note that I’m using the term “HOB” here more generically, as
> there are typically vendor specific structures beyond the resource
> descriptor HOB, which provides only a small subset of the information that
> needs to be passed between the boot phases.
> > >>
> > >>
> > >>
> > >> The whole point here is to provide mechanism to develop firmware
> that we can build ARM Server SoC’s that support *any* BL33 payload (e.g.
> EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at
> some point). In other-words, we are trying to come up with a TF-A that
> would be completely agnostic to the implementation of BL33 (i.e. BL33 is
> built completely independently by a separate entity – e.g. an ODM/OEM).
> > >>
> > >>
> > >>
> > >> Keep in mind, in the server/datacenter market segment we are not
> building vertically integrated systems with a single entity compiling
> firmware/software stacks like most folks in TF-A have become use to. There
> are two categories of higher level firmware code blobs in the
> server/datacenter model:
> > >>
> > >> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2,
> BL31, and *possibly* one or more BL32 instances
> > >> “Platform” or “board” firmware – in TF-A this may map to BL33
> and *possibly* one or more BL32 instances.
> > >>
> > >>
> > >>
> > >> Even the platform firmware stack could be further fragmented by
> having multiple entities involved in delivering the entire firmware stack:
> IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
> > >>
> > >>
> > >>
> > >> To support a broad range of platform designs with a broad range
> of memory devices, we need a crisp and clear contract between the SoC
> firmware that initializes memory (e.g. BL2) and how that platform boot
> firmware (e.g. BL33) gathers information about what memory that was
> initialized, at what speeds, NUMA topology, and many other relevant
> information that needs to be known and comprehended by the platform
> firmware and eventually by the platform software.
> > >>
> > >>
> > >>
> > >> I understand the versatility of DT, but I see two major problems
> with DT:
> > >>
> > >> DT requires more complicated parsing to get properties, and even
> more complex to dynamically set properties – this HOB structures may need
> to be generated in boot phases where DDR is not available, and therefore we
> will be extremely memory constrained.
> > >> DT is probably overkill for this purpose – We really just want a
> list of pointers to simple C structures that code cast (e.g. JEDEC SPD data
> blob)
> > >>
> > >>
> > >>
> > >> I think that we should not mix the efforts around DT/ACPI specs
> with what we are doing here, because those specs and concepts were
> developed for a completely different purpose (i.e. abstractions needed for
> OS / RTOS software, and not necessarily suitable for firmware-to-firmware
> hand-offs).
> > >>
> > >>
> > >>
> > >> Frankly, I would personally push back pretty hard on defining
> SMC’s for something that should be one way information passing. Every SMC
> we add is another attack vector to the secure world and an increased burden
> on the folks that have to do security auditing and threat analysis. I see
> no benefit in exposing these boot/HOB/BOB structures at run-time via SMC
> calls.
> > >>
> > >>
> > >>
> > >> Please do let me know if you disagree and why. Look forward to
> discussing on this thread or on the call.
> > >>
> > >>
> > >>
> > >> @Simon Glass - Thanks for the pointer to bloblist. I briefly
> reviewed and it seems like a good baseline for what we may be looking for.
> > >>
> > >>
> > >>
> > >> That being said, I would say that there is some benefit in
> having some kind of unique identifiers (e.g. UUID or some unique signature)
> so that we can tie standardized data structures (based on some future TBD
> specs) to a particular ID. For example, if the TPM driver in BL33 is
> looking for the TPM structure in the HOB/BOB list, and may not care about
> the other data blobs. The driver needs a way to identify and locate the
> blob it cares about.
> > >>
> > >>
> > >>
> > >> The tag is intended to serve that purpose, although perhaps it
> should switch from an auto-allocating enum to one with explicit values for
> each entry and a range for 'local' use.
> > >>
> > >>
> > >>
> > >> I guess we can achieve this with the tag, but the problem with
> tag when you have eco-system with a lot of parties doing parallel
> development, you can end up with tag collisions and folks fighting about
> who has rights to what tag values. We would need some official process for
> folks to register tags for whatever new structures we define, or maybe some
> tag range for vendor specific structures. This comes with a lot of pain
> and bureaucracy. On the other hand, UUID has been a proven way to make it
> easy to just define your own blobs with *either* standard or vendor
> specific structures without worry of ID collisions between vendors.
> > >>
> > >>
> > >>
> > >> True. I think the pain is overstated, though. In this case I
> think we actually want something that can be shared between projects and
> orgs, so some amount of coordination could be considered a benefit. It
> could just be a github pull request. I find the UUID unfriendly and not
> just to code size and eyesight! Trying to discover what GUIDs mean or are
> valid is quite tricky. E.g. see this code:
> > >>
> > >>
> > >>
> > >> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
> > >> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
> > >> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
> > >>
> > >> (etc.)
> > >>
> > >>
> > >>
> > >> static struct guid_name {
> > >> efi_guid_t guid;
> > >> const char *name;
> > >> } guid_name[] = {
> > >> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
> > >> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
> > >> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM"
> },
> > >> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
> > >> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
> > >> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
> > >> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database
> ea" },
> > >> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database
> 9b" },
> > >>
> > >> (never figured out what those two are)
> > >>
> > >>
> > >> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
> > >> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
> > >> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory"
> },
> > >> { {}, "zero-guid" },
> > >> {}
> > >> };
> > >>
> > >> static const char *guid_to_name(const efi_guid_t *guid)
> > >> {
> > >> struct guid_name *entry;
> > >>
> > >> for (entry = guid_name; entry->name; entry++) {
> > >> if (!guidcmp(guid, &entry->guid))
> > >> return entry->name;
> > >> }
> > >>
> > >> return NULL;
> > >> }
> > >>
> > >>
> > >>
> > >> Believe it or not it took a fair bit of effort to find just that
> small list, with nearly every one in a separate doc, from memory.
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> We can probably debate whether there is any value in GUID/UUID
> or not during the call… but again, boblist seems like a reasonable starting
> point as an alternative to HOB.
> > >>
> > >>
> > >>
> > >> Indeed. There is certainly value in both approaches.
> > >>
> > >>
> > >>
> > >> Regards,
> > >>
> > >> Simon
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> Thanks,
> > >>
> > >> --Harb
> > >>
> > >>
> > >>
> > >> From: François Ozog <francois.ozog(a)linaro.org>
> > >> Sent: Tuesday, March 23, 2021 10:00 AM
> > >> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <
> rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
> > >> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
> > >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks
> (HOBs) for information passing between boot stages
> > >>
> > >>
> > >>
> > >> +Ron Minnich +Paul Isaac's
> > >>
> > >>
> > >>
> > >> Adding Ron and Paul because I think this interface should be
> also benefiting LinuxBoot efforts.
> > >>
> > >>
> > >>
> > >> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
> > >>
> > >> Hi,
> > >>
> > >>
> > >>
> > >> I propose we cover the topic at the next Trusted Substrate
> zoom call on April 8th 4pm CET.
> > >>
> > >>
> > >>
> > >> The agenda:
> > >>
> > >> ABI between non-secure firmware and the rest of firmware (EL3,
> S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
> > >>
> > >> runtime conditions here relates to DRAM size and topology
> detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
> > >>
> > >>
> > >>
> > >> For additional background on existing metadata: UEFI Platform
> Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
> > >>
> > >> Out of the ResourceType we care about is
> EFI_RESOURCE_SYSTEM_MEMORY.
> > >>
> > >> This HOB lacks memory NUMA attachment or something that could be
> related to fill SRAT table for ACPI or relevant DT proximity domains.
> > >>
> > >> HOB is not consistent accros platforms: some platforms (Arm)
> lists memory from the booting NUMA node, other platforms (x86) lists all
> memory from all NUMA nodes. (At least this is the case on the two platforms
> I tested).
> > >>
> > >>
> > >>
> > >> There are two proposals to use memory structures from SPL/BLx up
> to the handover function (as defined in the Device Tree technical report)
> which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or
> EDK2.
> > >>
> > >> I would propose we also discuss possibility of FF-A interface to
> actually query information or request actions to be done (this is a model
> actually used in some SoCs with proprietary SMC calls).
> > >>
> > >>
> > >>
> > >> Requirements (to be validated):
> > >>
> > >> - ACPI and DT hardware descriptions.
> > >>
> > >> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
> > >>
> > >> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot,
> TF-A/EDK2, TF-A/LinuxBoot)
> > >>
> > >> - at least allows complete DRAM description and "persistent"
> usage (reserved areas for secure world or other usages)
> > >>
> > >> - support secure world device assignment
> > >>
> > >>
> > >>
> > >> Cheers
> > >>
> > >>
> > >>
> > >> FF
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org>
> wrote:
> > >>
> > >> Hi,
> > >>
> > >> Can I suggest using bloblist for this instead? It is lightweight,
> > >> easier to parse, doesn't have GUIDs and is already used within
> U-Boot
> > >> for passing info between SPL/U-Boot, etc.
> > >>
> > >> Docs here:
> https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
> > >> Header file describes the format:
> > >> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
> > >>
> > >> Full set of unit tests:
> > >> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
> > >>
> > >> Regards,
> > >> Simon
> > >>
> > >> On Mon, 22 Mar 2021 at 23:58, François Ozog <
> francois.ozog(a)linaro.org> wrote:
> > >> >
> > >> > +Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>
> > >> >
> > >> > standardization is very much welcomed here and need to
> accommodate a very
> > >> > diverse set of situations.
> > >> > For example, TEE OS may need to pass memory reservations to
> BL33 or
> > >> > "capture" a device for the secure world.
> > >> >
> > >> > I have observed a number of architectures:
> > >> > 1) pass information from BLx to BLy in the form of a specific
> object
> > >> > 2) BLx called by BLy by a platform specific SMC to get
> information
> > >> > 3) BLx called by BLy by a platform specific SMC to perform
> Device Tree
> > >> > fixups
> > >> >
> > >> > I also imagined a standardized "broadcast" FF-A call so that
> any firmware
> > >> > element can either provide information or "do something".
> > >> >
> > >> > My understanding of your proposal is about standardizing on
> architecture 1)
> > >> > with the HOB format.
> > >> >
> > >> > The advantage of the HOB is simplicity but it may be difficult
> to implement
> > >> > schemes such as pruning a DT because device assignment in the
> secure world.
> > >> >
> > >> > In any case, it looks feasible to have TF-A and OP-TEE
> complement the list
> > >> > of HOBs to pass information downstream (the bootflow).
> > >> >
> > >> > It would be good to start with building the comprehensive list
> of
> > >> > information that need to be conveyed between firmware elements:
> > >> >
> > >> > information. | authoritative entity | reporting entity |
> information
> > >> > exchanged:
> > >> > dram | TFA | TFA
> |
> > >> > <format to be detailed, NUMA topology to build the SRAT table
> or DT
> > >> > equivalent?>
> > >> > PSCI | SCP | TFA?
> |
> > >> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
> > >> > secure SRAM | TFA. | TFA.
> |
> > >> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
> > >> > other? | |
> > >> > |
> > >> >
> > >> > Cheers
> > >> >
> > >> > FF
> > >> >
> > >> >
> > >> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
> > >> > tf-a(a)lists.trustedfirmware.org> wrote:
> > >> >
> > >> > > Hello Folks,
> > >> > >
> > >> > >
> > >> > >
> > >> > > I'm emailing to start an open discussion about the adoption
> of a concept
> > >> > > known as "hand-off blocks" or HOB to become a part of the
> TF-A Firmware
> > >> > > Framework Architecture (FFA). This is something that is a
> pretty major
> > >> > > pain point when it comes to the adoption of TF-A in ARM
> Server SoC’s
> > >> > > designed to enable a broad range of highly configurable
> datacenter
> > >> > > platforms.
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > > What is a HOB (Background)?
> > >> > >
> > >> > > ---------------------------
> > >> > >
> > >> > > UEFI PI spec describes a particular definition for how HOB
> may be used for
> > >> > > transitioning between the PEI and DXE boot phases, which is
> a good
> > >> > > reference point for this discussion, but not necessarily the
> exact solution
> > >> > > appropriate for TF-A.
> > >> > >
> > >> > >
> > >> > >
> > >> > > A HOB is simply a dynamically generated data structure
> passed in between
> > >> > > two boot phases. This is information that was obtained
> through discovery
> > >> > > and needs to be passed forward to the next boot phase
> *once*, with no API
> > >> > > needed to call back (e.g. no call back into previous
> firmware phase is
> > >> > > needed to fetch this information at run-time - it is simply
> passed one time
> > >> > > during boot).
> > >> > >
> > >> > >
> > >> > >
> > >> > > There may be one or more HOBs passed in between boot
> phases. If there are
> > >> > > more than one HOB that needs to be passed, this can be in a
> form of a "HOB
> > >> > > table", which (for example) could be a UUID indexed array of
> pointers to
> > >> > > HOB structures, used to locate a HOB of interest (based on
> UUID). In such
> > >> > > cases, instead of passing a single HOB, the boot phases may
> rely on passing
> > >> > > the pointer to the HOB table.
> > >> > >
> > >> > >
> > >> > >
> > >> > > This has been extremely useful concept to employ on highly
> configurable
> > >> > > systems that must rely on flexible discovery mechanisms to
> initialize and
> > >> > > boot the system. This is especially helpful when you have
> multiple
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > > Why do we need HOBs in TF-A?:
> > >> > >
> > >> > > -----------------------------
> > >> > >
> > >> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM
> Server SoC in
> > >> > > a way that is SoC specific *but* platform agnostic. This
> means that a
> > >> > > single ARM SoC that a SiP may deliver to customers may
> provide a single
> > >> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to
> support a broad
> > >> > > range of platform designs and configurations in order to
> boot a platform
> > >> > > specific firmware (e.g. BL33 and possibly even BL32 code).
> In order to
> > >> > > achieve this, the platform configuration must be
> *discovered* instead of
> > >> > > statically compiled as it is today in TF-A via device tree
> based
> > >> > > enumeration. The mechanisms of discovery may differ broadly
> depending on
> > >> > > the relevant industry standard, or in some cases may have
> rely on SiP
> > >> > > specific discovery flows.
> > >> > >
> > >> > >
> > >> > >
> > >> > > For example: On server systems that support a broad range
> DIMM memory
> > >> > > population/topologies, all the necessary information
> required to boot is
> > >> > > fully discovered via standard JEDEC Serial Presence Detect
> (SPD) over an
> > >> > > I2C bus. Leveraging the SPD bus, may platform variants
> could be supported
> > >> > > with a single TF-A binary. Not only is this information
> required to
> > >> > > initialize memory in early boot phases (e.g. BL2), the
> subsequent boot
> > >> > > phases will also need this SPD info to construct a system
> physical address
> > >> > > map and properly initialize the MMU based on the memory
> present, and where
> > >> > > the memory may be present. Subsequent boot phases (e.g.
> BL33 / UEFI) may
> > >> > > need to generate standard firmware tables to the operating
> systems, such as
> > >> > > SMBIOS tables describing DIMM topology and various ACPI
> tables (e.g. SLIT,
> > >> > > SRAT, even NFIT if NVDIMM's are present).
> > >> > >
> > >> > >
> > >> > >
> > >> > > In short, it all starts with a standardized or vendor
> specific discovery
> > >> > > flow in an early boot stage (e.g. BL1/BL2), followed by the
> passing of
> > >> > > information to the next boot stages (e.g. BL31/BL32/BL33).
> > >> > >
> > >> > >
> > >> > >
> > >> > > Today, every HOB may be a vendor specific structure, but in
> the future
> > >> > > there may be benefit of defining standard HOBs. This may be
> useful for
> > >> > > memory discovery, passing the system physical address map,
> enabling TPM
> > >> > > measured boot, and potentially many other common HOB
> use-cases.
> > >> > >
> > >> > >
> > >> > >
> > >> > > It would be extremely beneficial to the datacenter market
> segment if the
> > >> > > TF-A community would adopt this concept of information
> passing between all
> > >> > > boot phases as opposed to rely solely on device tree
> enumeration. This is
> > >> > > not intended to replace device tree, rather intended as an
> alternative way
> > >> > > to describe the info that must be discovered and dynamically
> generated.
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > > Conclusion:
> > >> > >
> > >> > > -----------
> > >> > >
> > >> > > We are proposing that the TF-A community begin pursuing the
> adoption of
> > >> > > HOBs as a mechanism used for information exchange between
> each boot stage
> > >> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)?
> Longer term we
> > >> > > want to explore standardizing some HOB structures for the
> BL33 phase (e.g.
> > >> > > UEFI HOB structures), but initially would like to agree on
> this being a
> > >> > > useful mechanism used to pass information between each boot
> stage.
> > >> > >
> > >> > >
> > >> > >
> > >> > > Thanks,
> > >> > >
> > >> > > --Harb
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > >
> > >> > > --
> > >> > > TF-A mailing list
> > >> > > TF-A(a)lists.trustedfirmware.org
> > >> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >> > >
> > >> >
> > >> >
> > >> > --
> > >> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing
> Group*
> > >> > T: +33.67221.6485
> > >> > francois.ozog(a)linaro.org | Skype: ffozog
> > >> > _______________________________________________
> > >> > boot-architecture mailing list
> > >> > boot-architecture(a)lists.linaro.org
> > >> > https://lists.linaro.org/mailman/listinfo/boot-architecture
> > >>
> > >>
> > >>
> > >>
> > >> --
> > >>
> > >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing
> Group
> > >>
> > >> T: +33.67221.6485
> > >> francois.ozog(a)linaro.org | Skype: ffozog
> > >>
> > >>
> > >>
> > >> --
> > >> TF-A mailing list
> > >> TF-A(a)lists.trustedfirmware.org
> > >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >>
> > >>
> > >>
> > >>
> > >> --
> > >>
> > >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing
> Group
> > >>
> > >> T: +33.67221.6485
> > >> francois.ozog(a)linaro.org | Skype: ffozog
> > >>
> > >>
> > >>
> > >> --
> > >> TF-A mailing list
> > >> TF-A(a)lists.trustedfirmware.org
> > >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >>
> > >> --
> > >> TF-A mailing list
> > >> TF-A(a)lists.trustedfirmware.org
> > >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >>
> > >>
> > >>
> > >>
> > >> --
> > >>
> > >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing
> Group
> > >>
> > >> T: +33.67221.6485
> > >> francois.ozog(a)linaro.org | Skype: ffozog
> > >>
> > >>
> > >
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
On 5/18/21 8:59 PM, Madhukar Pappireddy via TF-A wrote:
> Hi,
>
> I tried to summarize the discussions in the previous TF-A tech forum regarding the proposal to adopt Hand-off Blocks (HOBs) for passing information along the boot chain. I am certain I could not capture all suggestions/concerns brought up during the call. I apologize if I missed and/or misinterpreted any comments and would appreciate it if everyone could share their thoughts in response to this email thread.
>
> The idea is to share information to other boot phases:
>> Dynamic information: Created during runtime. Shared in the form of a chain of blobs(built as a linked list of C structure objects i.e., HOB list).
>> Static information: Known at compile time. Historically, shared through the use of Device Tree/ACPI tables
>
> Both the above requirements are common in many ecosystems and need to co-exist.
>
> There are broadly 3 problems to solve:
> 1. Format of HOB structures: It looks like the consensus is that we could use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in u-boot).
> 2. Identification of HOB list entries: There is a debate about whether tags would suffice or if the HOB list producer and consumer would depend on UUID/GUIDs for identifying a specific HOB structure. Another suggestion was to use a hybrid approach. Reserve a single tag ID for identifying/constructing a HOB structure that further leverages UUID based identifier. This way, the generic HOB list doesn't need to support UUIDs and can work with tags.
> 3. The design contract for the static interface between two boot phases: The problem at hand is whether to pass a pointer to a HOB list or a device tree blob through the general-purpose registers for configuration hand-off between two boot phases. Some proposals that came up:
> > Proposal 1: Always pass a pointer to the device tree blob through the GP register and capture the pointer to the HOB list as a property of a node that is uniquely identifiable by the downstream boot phase. This needs to define a device tree binding such that producer and consumer agree on the information passed.
Using DT to pass platform info at this level is sort of crazy on an ACPI
machine which won't have native DTs. Meaning there is an additional
level of unnecessary indirection that needs to be converted back into a
format which can be utilized by AML and other parts of the ACPI stack.
Its also helpful to look at what has become of the rpi4 uefi port, where
the DT is actually dynamic (or provided by the user, complete with HAT
overlays) and fed into the lower level firmware and propagated up
through the system. The result has frequently been subtle bugs or boot
failures because the DT provided by the rpi foundation as part of their
low level firwmare+kernel stack is modified by their low level firwmare,
and it differs from the DT in mainline linux. So more than once we have
discovered that there isn't a single DT that can be boot both the
current firmware and a current mainline linux. In the past there was
even an option to use one DT for the firmware and an entirely seperate
one for linux, but that was removed when it bacame apparent you couldn't
have the lower level firmwaer say modifying MMIO windows for the PCIe
subsystem and not propogate that into the other user supplied DT.
At this point the uefi firmware on the rpi will provide a DT if asked,
but it doesn't parse it nor does anything in the AML. Instead everything
is done directly against the hardware, even when the HW registers aren't
well documented.That is in large parts because the AML requirements are
a lot different than what is provided in the DT.
> > Proposal 2: Pass a pointer to a generic container through the GP register that can be interpreted appropriately by both boot loaders(i.e., producer and consumer of the boot info). This container can either be a dtb or a HOB list which can be simply inferred by checking for a magic header that indicates if the buffer appears to be a flattened device tree.
> > One another concern that was brought up offline is to make sure we don't break current design contracts between various boot loader phases in TF-A. Many of the general-purpose registers have a designated purpose such as to share configurations between BL images( such as firmware config dtb, SoC config dtb, Non trusted firmware config dtb, memory layout, entry point info, etc.).
>
> If I am not mistaken, a single design may not fit the needs of every segment(client, Infra, embedded) and the forum is open to solutions tailored for individual segments. Joanna will be sending a follow up email with more information about future TF-A tech forums that serves as a platform for further discussions.
>
> Thanks,
> Madhukar
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A
> Sent: Sunday, May 16, 2021 5:19 AM
> To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org>
> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>
> Apologies I failed with the recording. Manish/Madhu will reply early next week with the slides and some notes to help with a follow up session which we hope to hold this Thursday. Invite and agenda will also be sent out early next week.
>
> Thanks
>
> Joanna
>
> On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi,
>
> Do we have slides and video from last week's discussion?
>
> Thanks,
> Okash
>
>
> On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
> <tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi Harb,
> >
> > Thanks for the idea. I am still not completely sure what benefit UUID provides to an open project. I'd like to propose something different, more in the spirit of open collaboration. I also worry that the word 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring closed-source firmware and the continued decline of open-source projects. It really should not be.
> >
> > So I suggest: Use simple integer IDs and reserve some area for 'private' use. If you want to collaborate across projects outside your company, you either need to allocate a 'public' ID or agree privately between the parties which private ID to use.
> >
> > This means that the default and easiest option is for collaboration and a public ID, with private ones (whose purpose may be secret) reserved just for private use.
> >
> > Regards,
> > Simon
> >
> > On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
> >>
> >> Hey Folks,
> >>
> >> We wanted to put out a middle-ground proposal to help guide the discussion on the call tomorrow.
> >>
> >>
> >>
> >> A proposal that we have been discussing offline involves reserving a single tag ID for the purpose of construction UEFI PI HOB List structure, and that tag would be used to identify a HOB-specific structure that does leverage UUID based identifier. This will eliminate the burden of having to support UUID as the tag, and this enables projects that require UUID based identifiers for the broad range of HOB structures that need to be produced during the booting of the platform. Once we have a tag for a HOB list, this will enable various HOB producers that can add/extend the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other side (i.e. whatever the BL33 image is booting on that platform).
> >>
> >>
> >>
> >> Essentially, the idea is if someone would like to support HOB structures in a standard way using TF-A, they would wrap it up in a BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we identify the structure as a HOB list is with this new reserved tag.
> >>
> >>
> >>
> >> Hopefully that makes sense and less contentious. Look forward to discuss this further on the call.
> >>
> >>
> >>
> >> Thanks,
> >>
> >> --Harb
> >>
> >>
> >>
> >> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
> >> Sent: Friday, April 30, 2021 8:14 AM
> >> To: François Ozog <francois.ozog(a)linaro.org>
> >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
> >>
> >>
> >>
> >> Hi All,
> >>
> >>
> >>
> >> Please find invite for next TF-A Tech Forum session to continue our discussions on HOB implementation, feel free to forward it to others.
> >>
> >>
> >>
> >> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
> >>
> >>
> >>
> >> Agenda:
> >>
> >> Discussion Session: Static and Dynamic Information Handling in TF-A
> >>
> >> Lead by Manish Pandey and Madhukar Pappireddy
> >>
> >> · There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
> >>
> >> The requirement is two-fold:
> >>
> >> 1. Passing static information(config files)
> >>
> >> 2. Passing dynamic information (Hob list)
> >>
> >> In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
> >>
> >>
> >>
> >> The two specific item which we would like to discuss are:
> >>
> >> 1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
> >>
> >> 2. Standardization on Physical register use to pass base of HoB data structure.
> >>
> >> References:
> >>
> >> [1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
> >>
> >> [2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
> >>
> >>
> >>
> >> Thanks
> >>
> >>
> >>
> >> Joanna
> >>
> >>
> >>
> >> You have been invited to the following event.
> >>
> >> TF-A Tech Forum
> >>
> >> When
> >>
> >> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
> >>
> >> Calendar
> >>
> >> tf-a(a)lists.trustedfirmware.org
> >>
> >> Who
> >>
> >> •
> >>
> >> Bill Fletcher- creator
> >>
> >> •
> >>
> >> tf-a(a)lists.trustedfirmware.org
> >>
> >> more details »
> >>
> >>
> >>
> >> We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
> >>
> >>
> >>
> >> Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
> >>
> >>
> >>
> >> Trusted Firmware is inviting you to a scheduled Zoom meeting.
> >>
> >>
> >>
> >> Join Zoom Meeting
> >>
> >> https://zoom.us/j/9159704974
> >>
> >>
> >>
> >> Meeting ID: 915 970 4974
> >>
> >>
> >>
> >> One tap mobile
> >>
> >> +16465588656,,9159704974# US (New York)
> >>
> >> +16699009128,,9159704974# US (San Jose)
> >>
> >>
> >>
> >> Dial by your location
> >>
> >> +1 646 558 8656 US (New York)
> >>
> >> +1 669 900 9128 US (San Jose)
> >>
> >> 877 853 5247 US Toll-free
> >>
> >> 888 788 0099 US Toll-free
> >>
> >> Meeting ID: 915 970 4974
> >>
> >> Find your local number: https://zoom.us/u/ad27hc6t7h
> >>
> >>
> >>
> >> ________________________________
> >>
> >> From: François Ozog <francois.ozog(a)linaro.org>
> >> Sent: 08 April 2021 16:50
> >> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
> >> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
> >>
> >>
> >>
> >> Hi
> >>
> >>
> >>
> >> here is the meeting recording:
> >>
> >> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%z
> >>
> >>
> >>
> >> I am really sorry about the confusion related to the meeting time. I have now understood: the Collaborate portal uses a specific calendar which is tied to US/Chicago timezone while the actual Google Calendar is tied to Central Europe timezone. I am going to drop the Collaborate portal and use a shared Google calendar (it should be visible on the trusted-substrate.org page).
> >>
> >>
> >>
> >> I'll try to summarize what I learnt and highlight my view on what can be next steps in a future mail.
> >>
> >>
> >>
> >> Cheers
> >>
> >>
> >>
> >> FF
> >>
> >>
> >>
> >> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
> >>
> >> Hi,
> >>
> >>
> >>
> >> From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
> >>
> >>
> >>
> >> To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
> >>
> >>
> >>
> >> The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
> >>
> >>
> >>
> >> One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
> >>
> >>
> >>
> >> Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
> >>
> >>
> >>
> >> Looking forward to having further discussions on zoom call today.
> >>
> >>
> >>
> >> Thanks
> >>
> >> Manish P
> >>
> >>
> >>
> >> ________________________________
> >>
> >> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
> >> Sent: 25 March 2021 02:43
> >> To: Simon Glass <sjg(a)chromium.org>
> >> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
> >>
> >>
> >>
> >> Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
> >>
> >>
> >>
> >> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> >>
> >> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> >>
> >> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
> >>
> >>
> >>
> >> It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
> >>
> >>
> >>
> >> I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
> >>
> >>
> >>
> >> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
> >>
> >> Hi Harb,
> >>
> >>
> >>
> >> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
> >>
> >> Hello Folks,
> >>
> >> Appreciate the feedback and replies on this. Glad to see that there is interest in this topic.
> >>
> >>
> >>
> >> I try to address the comments/feedback from Francois and Simon below….
> >>
> >>
> >>
> >> @François Ozog – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
> >>
> >>
> >>
> >> Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
> >>
> >>
> >>
> >> The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
> >>
> >>
> >>
> >> Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
> >>
> >> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
> >> “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
> >>
> >>
> >>
> >> Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
> >>
> >>
> >>
> >> To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
> >>
> >>
> >>
> >> I understand the versatility of DT, but I see two major problems with DT:
> >>
> >> DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
> >> DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
> >>
> >>
> >>
> >> I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
> >>
> >>
> >>
> >> Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
> >>
> >>
> >>
> >> Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
> >>
> >>
> >>
> >> @Simon Glass - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
> >>
> >>
> >>
> >> That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
> >>
> >>
> >>
> >> The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
> >>
> >>
> >>
> >> I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
> >>
> >>
> >>
> >> True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
> >>
> >>
> >>
> >> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
> >> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
> >> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
> >>
> >> (etc.)
> >>
> >>
> >>
> >> static struct guid_name {
> >> efi_guid_t guid;
> >> const char *name;
> >> } guid_name[] = {
> >> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
> >> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
> >> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
> >> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
> >> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
> >> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
> >> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
> >> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
> >>
> >> (never figured out what those two are)
> >>
> >>
> >> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
> >> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
> >> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
> >> { {}, "zero-guid" },
> >> {}
> >> };
> >>
> >> static const char *guid_to_name(const efi_guid_t *guid)
> >> {
> >> struct guid_name *entry;
> >>
> >> for (entry = guid_name; entry->name; entry++) {
> >> if (!guidcmp(guid, &entry->guid))
> >> return entry->name;
> >> }
> >>
> >> return NULL;
> >> }
> >>
> >>
> >>
> >> Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
> >>
> >>
> >>
> >>
> >>
> >> We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
> >>
> >>
> >>
> >> Indeed. There is certainly value in both approaches.
> >>
> >>
> >>
> >> Regards,
> >>
> >> Simon
> >>
> >>
> >>
> >>
> >>
> >> Thanks,
> >>
> >> --Harb
> >>
> >>
> >>
> >> From: François Ozog <francois.ozog(a)linaro.org>
> >> Sent: Tuesday, March 23, 2021 10:00 AM
> >> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
> >> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
> >> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
> >>
> >>
> >>
> >> +Ron Minnich +Paul Isaac's
> >>
> >>
> >>
> >> Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
> >>
> >>
> >>
> >> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
> >>
> >> Hi,
> >>
> >>
> >>
> >> I propose we cover the topic at the next Trusted Substrate zoom call on April 8th 4pm CET.
> >>
> >>
> >>
> >> The agenda:
> >>
> >> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
> >>
> >> runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
> >>
> >>
> >>
> >> For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
> >>
> >> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
> >>
> >> This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
> >>
> >> HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
> >>
> >>
> >>
> >> There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
> >>
> >> I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
> >>
> >>
> >>
> >> Requirements (to be validated):
> >>
> >> - ACPI and DT hardware descriptions.
> >>
> >> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
> >>
> >> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
> >>
> >> - at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
> >>
> >> - support secure world device assignment
> >>
> >>
> >>
> >> Cheers
> >>
> >>
> >>
> >> FF
> >>
> >>
> >>
> >>
> >>
> >> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
> >>
> >> Hi,
> >>
> >> Can I suggest using bloblist for this instead? It is lightweight,
> >> easier to parse, doesn't have GUIDs and is already used within U-Boot
> >> for passing info between SPL/U-Boot, etc.
> >>
> >> Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
> >> Header file describes the format:
> >> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
> >>
> >> Full set of unit tests:
> >> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
> >>
> >> Regards,
> >> Simon
> >>
> >> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org> wrote:
> >> >
> >> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
> >> >
> >> > standardization is very much welcomed here and need to accommodate a very
> >> > diverse set of situations.
> >> > For example, TEE OS may need to pass memory reservations to BL33 or
> >> > "capture" a device for the secure world.
> >> >
> >> > I have observed a number of architectures:
> >> > 1) pass information from BLx to BLy in the form of a specific object
> >> > 2) BLx called by BLy by a platform specific SMC to get information
> >> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
> >> > fixups
> >> >
> >> > I also imagined a standardized "broadcast" FF-A call so that any firmware
> >> > element can either provide information or "do something".
> >> >
> >> > My understanding of your proposal is about standardizing on architecture 1)
> >> > with the HOB format.
> >> >
> >> > The advantage of the HOB is simplicity but it may be difficult to implement
> >> > schemes such as pruning a DT because device assignment in the secure world.
> >> >
> >> > In any case, it looks feasible to have TF-A and OP-TEE complement the list
> >> > of HOBs to pass information downstream (the bootflow).
> >> >
> >> > It would be good to start with building the comprehensive list of
> >> > information that need to be conveyed between firmware elements:
> >> >
> >> > information. | authoritative entity | reporting entity | information
> >> > exchanged:
> >> > dram | TFA | TFA |
> >> > <format to be detailed, NUMA topology to build the SRAT table or DT
> >> > equivalent?>
> >> > PSCI | SCP | TFA? |
> >> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
> >> > secure SRAM | TFA. | TFA. |
> >> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
> >> > other? | |
> >> > |
> >> >
> >> > Cheers
> >> >
> >> > FF
> >> >
> >> >
> >> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
> >> > tf-a(a)lists.trustedfirmware.org> wrote:
> >> >
> >> > > Hello Folks,
> >> > >
> >> > >
> >> > >
> >> > > I'm emailing to start an open discussion about the adoption of a concept
> >> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
> >> > > Framework Architecture (FFA). This is something that is a pretty major
> >> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
> >> > > designed to enable a broad range of highly configurable datacenter
> >> > > platforms.
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > What is a HOB (Background)?
> >> > >
> >> > > ---------------------------
> >> > >
> >> > > UEFI PI spec describes a particular definition for how HOB may be used for
> >> > > transitioning between the PEI and DXE boot phases, which is a good
> >> > > reference point for this discussion, but not necessarily the exact solution
> >> > > appropriate for TF-A.
> >> > >
> >> > >
> >> > >
> >> > > A HOB is simply a dynamically generated data structure passed in between
> >> > > two boot phases. This is information that was obtained through discovery
> >> > > and needs to be passed forward to the next boot phase *once*, with no API
> >> > > needed to call back (e.g. no call back into previous firmware phase is
> >> > > needed to fetch this information at run-time - it is simply passed one time
> >> > > during boot).
> >> > >
> >> > >
> >> > >
> >> > > There may be one or more HOBs passed in between boot phases. If there are
> >> > > more than one HOB that needs to be passed, this can be in a form of a "HOB
> >> > > table", which (for example) could be a UUID indexed array of pointers to
> >> > > HOB structures, used to locate a HOB of interest (based on UUID). In such
> >> > > cases, instead of passing a single HOB, the boot phases may rely on passing
> >> > > the pointer to the HOB table.
> >> > >
> >> > >
> >> > >
> >> > > This has been extremely useful concept to employ on highly configurable
> >> > > systems that must rely on flexible discovery mechanisms to initialize and
> >> > > boot the system. This is especially helpful when you have multiple
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > Why do we need HOBs in TF-A?:
> >> > >
> >> > > -----------------------------
> >> > >
> >> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
> >> > > a way that is SoC specific *but* platform agnostic. This means that a
> >> > > single ARM SoC that a SiP may deliver to customers may provide a single
> >> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
> >> > > range of platform designs and configurations in order to boot a platform
> >> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
> >> > > achieve this, the platform configuration must be *discovered* instead of
> >> > > statically compiled as it is today in TF-A via device tree based
> >> > > enumeration. The mechanisms of discovery may differ broadly depending on
> >> > > the relevant industry standard, or in some cases may have rely on SiP
> >> > > specific discovery flows.
> >> > >
> >> > >
> >> > >
> >> > > For example: On server systems that support a broad range DIMM memory
> >> > > population/topologies, all the necessary information required to boot is
> >> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
> >> > > I2C bus. Leveraging the SPD bus, may platform variants could be supported
> >> > > with a single TF-A binary. Not only is this information required to
> >> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
> >> > > phases will also need this SPD info to construct a system physical address
> >> > > map and properly initialize the MMU based on the memory present, and where
> >> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
> >> > > need to generate standard firmware tables to the operating systems, such as
> >> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
> >> > > SRAT, even NFIT if NVDIMM's are present).
> >> > >
> >> > >
> >> > >
> >> > > In short, it all starts with a standardized or vendor specific discovery
> >> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
> >> > > information to the next boot stages (e.g. BL31/BL32/BL33).
> >> > >
> >> > >
> >> > >
> >> > > Today, every HOB may be a vendor specific structure, but in the future
> >> > > there may be benefit of defining standard HOBs. This may be useful for
> >> > > memory discovery, passing the system physical address map, enabling TPM
> >> > > measured boot, and potentially many other common HOB use-cases.
> >> > >
> >> > >
> >> > >
> >> > > It would be extremely beneficial to the datacenter market segment if the
> >> > > TF-A community would adopt this concept of information passing between all
> >> > > boot phases as opposed to rely solely on device tree enumeration. This is
> >> > > not intended to replace device tree, rather intended as an alternative way
> >> > > to describe the info that must be discovered and dynamically generated.
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > Conclusion:
> >> > >
> >> > > -----------
> >> > >
> >> > > We are proposing that the TF-A community begin pursuing the adoption of
> >> > > HOBs as a mechanism used for information exchange between each boot stage
> >> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
> >> > > want to explore standardizing some HOB structures for the BL33 phase (e.g.
> >> > > UEFI HOB structures), but initially would like to agree on this being a
> >> > > useful mechanism used to pass information between each boot stage.
> >> > >
> >> > >
> >> > >
> >> > > Thanks,
> >> > >
> >> > > --Harb
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > >
> >> > > --
> >> > > TF-A mailing list
> >> > > TF-A(a)lists.trustedfirmware.org
> >> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >> > >
> >> >
> >> >
> >> > --
> >> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
> >> > T: +33.67221.6485
> >> > francois.ozog(a)linaro.org | Skype: ffozog
> >> > _______________________________________________
> >> > boot-architecture mailing list
> >> > boot-architecture(a)lists.linaro.org
> >> > https://lists.linaro.org/mailman/listinfo/boot-architecture
> >>
> >>
> >>
> >>
> >> --
> >>
> >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> >>
> >> T: +33.67221.6485
> >> francois.ozog(a)linaro.org | Skype: ffozog
> >>
> >>
> >>
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >>
> >>
> >>
> >>
> >> --
> >>
> >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> >>
> >> T: +33.67221.6485
> >> francois.ozog(a)linaro.org | Skype: ffozog
> >>
> >>
> >>
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >>
> >> --
> >> TF-A mailing list
> >> TF-A(a)lists.trustedfirmware.org
> >> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >>
> >>
> >>
> >>
> >> --
> >>
> >> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> >>
> >> T: +33.67221.6485
> >> francois.ozog(a)linaro.org | Skype: ffozog
> >>
> >>
> >
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
Hi Everyone,
I am cancelling this week’s TF-A Tech Forum as I don’t have any areas to present/discuss.
I expect the session on 3rd June to be a follow on session of that held below from 2 weeks ago. A write up was posted yesterday to the mailing list.
Thanks
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Joanna Farley via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Joanna Farley <Joanna.Farley(a)arm.com>
Date: Thursday, 29 April 2021 at 17:59
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] TF-A Tech Forum Agenda @ Thr 6th May 2021 16:00-1700 BST
Hi All,
The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
Agenda:
* Discussion Session: Static and Dynamic Information Handling in TF-A
* Lead by Manish Pandy and Madhukar Pappireddy
· There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
The requirement is two-fold:
1. Passing static information(config files)
2. Passing dynamic information (Hob list)
In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
The two specific item which we would like to discuss are:
1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
2. Standardization on Physical register use to pass base of HoB data structure.
References:
[1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
[2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
Thanks
Joanna
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•
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This event has been canceled with this note:
"Cancelling the TF-A Tech Forum session this week. We expect the session on
3rd of June to be a follow up of the Discussion Session: Static and Dynamic
Information Handling in TF-A held 2 weeks ago."
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
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When: Thu May 20, 2021 4pm – 5pm United Kingdom Time
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* Bill Fletcher - creator
* marek.bykowski(a)gmail.com
* okash.khawaja(a)gmail.com
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Looks tf-a(a)lists.trustedfirmware.org got dropped. Adding that back in.
Joanna
On 19/05/2021, 15:33, "Joanna Farley" <Joanna.Farley(a)arm.com> wrote:
It’s a bit short notice to host another TF-A Tech-forum call on this tomorrow for a live debate as well as Manish who led the call last time is not available this week. So I propose our next TF-A Techforum session on Thursday 3rd June at 4pm BST and between now and then email discussions can possibly be pursued.
From a TF-A perspective we want to help facilitate a number of segments/use-cases we heard about as Madhu mentions below. As such any enablement we can provide in TF-A common code would be good to identify that contributors to other segments/use-cases can build upon in shared platform code in TF-A or elsewhere outside the TF-A repository of that works better for those segments/use-cases.
Thanks
Joanna
On 19/05/2021, 03:50, "Madhukar Pappireddy" <Madhukar.Pappireddy(a)arm.com> wrote:
Attached slides presented by Manish in the TF-A tech forum.
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A
Sent: Tuesday, May 18, 2021 8:59 PM
To: Joanna Farley <Joanna.Farley(a)arm.com>; Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; tf-a(a)lists.trustedfirmware.org; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Hi,
I tried to summarize the discussions in the previous TF-A tech forum regarding the proposal to adopt Hand-off Blocks (HOBs) for passing information along the boot chain. I am certain I could not capture all suggestions/concerns brought up during the call. I apologize if I missed and/or misinterpreted any comments and would appreciate it if everyone could share their thoughts in response to this email thread.
The idea is to share information to other boot phases:
> Dynamic information: Created during runtime. Shared in the form of a chain of blobs(built as a linked list of C structure objects i.e., HOB list).
> Static information: Known at compile time. Historically, shared through the use of Device Tree/ACPI tables
Both the above requirements are common in many ecosystems and need to co-exist.
There are broadly 3 problems to solve:
1. Format of HOB structures: It looks like the consensus is that we could use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in u-boot).
2. Identification of HOB list entries: There is a debate about whether tags would suffice or if the HOB list producer and consumer would depend on UUID/GUIDs for identifying a specific HOB structure. Another suggestion was to use a hybrid approach. Reserve a single tag ID for identifying/constructing a HOB structure that further leverages UUID based identifier. This way, the generic HOB list doesn't need to support UUIDs and can work with tags.
3. The design contract for the static interface between two boot phases: The problem at hand is whether to pass a pointer to a HOB list or a device tree blob through the general-purpose registers for configuration hand-off between two boot phases. Some proposals that came up:
> Proposal 1: Always pass a pointer to the device tree blob through the GP register and capture the pointer to the HOB list as a property of a node that is uniquely identifiable by the downstream boot phase. This needs to define a device tree binding such that producer and consumer agree on the information passed.
> Proposal 2: Pass a pointer to a generic container through the GP register that can be interpreted appropriately by both boot loaders(i.e., producer and consumer of the boot info). This container can either be a dtb or a HOB list which can be simply inferred by checking for a magic header that indicates if the buffer appears to be a flattened device tree.
> One another concern that was brought up offline is to make sure we don't break current design contracts between various boot loader phases in TF-A. Many of the general-purpose registers have a designated purpose such as to share configurations between BL images( such as firmware config dtb, SoC config dtb, Non trusted firmware config dtb, memory layout, entry point info, etc.).
If I am not mistaken, a single design may not fit the needs of every segment(client, Infra, embedded) and the forum is open to solutions tailored for individual segments. Joanna will be sending a follow up email with more information about future TF-A tech forums that serves as a platform for further discussions.
Thanks,
Madhukar
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A
Sent: Sunday, May 16, 2021 5:19 AM
To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Apologies I failed with the recording. Manish/Madhu will reply early next week with the slides and some notes to help with a follow up session which we hope to hold this Thursday. Invite and agenda will also be sent out early next week.
Thanks
Joanna
On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi,
Do we have slides and video from last week's discussion?
Thanks,
Okash
On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> Thanks for the idea. I am still not completely sure what benefit UUID provides to an open project. I'd like to propose something different, more in the spirit of open collaboration. I also worry that the word 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring closed-source firmware and the continued decline of open-source projects. It really should not be.
>
> So I suggest: Use simple integer IDs and reserve some area for 'private' use. If you want to collaborate across projects outside your company, you either need to allocate a 'public' ID or agree privately between the parties which private ID to use.
>
> This means that the default and easiest option is for collaboration and a public ID, with private ones (whose purpose may be secret) reserved just for private use.
>
> Regards,
> Simon
>
> On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hey Folks,
>>
>> We wanted to put out a middle-ground proposal to help guide the discussion on the call tomorrow.
>>
>>
>>
>> A proposal that we have been discussing offline involves reserving a single tag ID for the purpose of construction UEFI PI HOB List structure, and that tag would be used to identify a HOB-specific structure that does leverage UUID based identifier. This will eliminate the burden of having to support UUID as the tag, and this enables projects that require UUID based identifiers for the broad range of HOB structures that need to be produced during the booting of the platform. Once we have a tag for a HOB list, this will enable various HOB producers that can add/extend the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other side (i.e. whatever the BL33 image is booting on that platform).
>>
>>
>>
>> Essentially, the idea is if someone would like to support HOB structures in a standard way using TF-A, they would wrap it up in a BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we identify the structure as a HOB list is with this new reserved tag.
>>
>>
>>
>> Hopefully that makes sense and less contentious. Look forward to discuss this further on the call.
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Sent: Friday, April 30, 2021 8:14 AM
>> To: François Ozog <francois.ozog(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi All,
>>
>>
>>
>> Please find invite for next TF-A Tech Forum session to continue our discussions on HOB implementation, feel free to forward it to others.
>>
>>
>>
>> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
>>
>>
>>
>> Agenda:
>>
>> Discussion Session: Static and Dynamic Information Handling in TF-A
>>
>> Lead by Manish Pandey and Madhukar Pappireddy
>>
>> · There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
>>
>> The requirement is two-fold:
>>
>> 1. Passing static information(config files)
>>
>> 2. Passing dynamic information (Hob list)
>>
>> In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
>>
>>
>>
>> The two specific item which we would like to discuss are:
>>
>> 1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
>>
>> 2. Standardization on Physical register use to pass base of HoB data structure.
>>
>> References:
>>
>> [1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
>>
>> [2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
>>
>>
>>
>> Thanks
>>
>>
>>
>> Joanna
>>
>>
>>
>> You have been invited to the following event.
>>
>> TF-A Tech Forum
>>
>> When
>>
>> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
>>
>> Calendar
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> Who
>>
>> •
>>
>> Bill Fletcher- creator
>>
>> •
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> more details »
>>
>>
>>
>> We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
>>
>>
>>
>> Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
>>
>>
>>
>> Trusted Firmware is inviting you to a scheduled Zoom meeting.
>>
>>
>>
>> Join Zoom Meeting
>>
>> https://zoom.us/j/9159704974
>>
>>
>>
>> Meeting ID: 915 970 4974
>>
>>
>>
>> One tap mobile
>>
>> +16465588656,,9159704974# US (New York)
>>
>> +16699009128,,9159704974# US (San Jose)
>>
>>
>>
>> Dial by your location
>>
>> +1 646 558 8656 US (New York)
>>
>> +1 669 900 9128 US (San Jose)
>>
>> 877 853 5247 US Toll-free
>>
>> 888 788 0099 US Toll-free
>>
>> Meeting ID: 915 970 4974
>>
>> Find your local number: https://zoom.us/u/ad27hc6t7h
>>
>>
>>
>> ________________________________
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: 08 April 2021 16:50
>> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi
>>
>>
>>
>> here is the meeting recording:
>>
>> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%z
>>
>>
>>
>> I am really sorry about the confusion related to the meeting time. I have now understood: the Collaborate portal uses a specific calendar which is tied to US/Chicago timezone while the actual Google Calendar is tied to Central Europe timezone. I am going to drop the Collaborate portal and use a shared Google calendar (it should be visible on the trusted-substrate.org page).
>>
>>
>>
>> I'll try to summarize what I learnt and highlight my view on what can be next steps in a future mail.
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
>>
>>
>>
>> To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
>>
>>
>>
>> The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
>>
>>
>>
>> One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
>>
>>
>>
>> Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
>>
>>
>>
>> Looking forward to having further discussions on zoom call today.
>>
>>
>>
>> Thanks
>>
>> Manish P
>>
>>
>>
>> ________________________________
>>
>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
>> Sent: 25 March 2021 02:43
>> To: Simon Glass <sjg(a)chromium.org>
>> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
>>
>>
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>>
>>
>> It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
>>
>>
>>
>> I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
>>
>>
>>
>> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi Harb,
>>
>>
>>
>> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hello Folks,
>>
>> Appreciate the feedback and replies on this. Glad to see that there is interest in this topic.
>>
>>
>>
>> I try to address the comments/feedback from Francois and Simon below….
>>
>>
>>
>> @François Ozog – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
>>
>>
>>
>> Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
>>
>>
>>
>> The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
>>
>>
>>
>> Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
>>
>> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
>> “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
>>
>>
>>
>> Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
>>
>>
>>
>> To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
>>
>>
>>
>> I understand the versatility of DT, but I see two major problems with DT:
>>
>> DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
>> DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
>>
>>
>>
>> I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
>>
>>
>>
>> Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
>>
>>
>>
>> Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
>>
>>
>>
>> @Simon Glass - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
>>
>>
>>
>> That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
>>
>>
>>
>> The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
>>
>>
>>
>> I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
>>
>>
>>
>> True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
>>
>>
>>
>> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
>> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
>> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
>>
>> (etc.)
>>
>>
>>
>> static struct guid_name {
>> efi_guid_t guid;
>> const char *name;
>> } guid_name[] = {
>> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
>> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
>> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
>> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
>> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
>> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
>>
>> (never figured out what those two are)
>>
>>
>> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
>> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
>> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
>> { {}, "zero-guid" },
>> {}
>> };
>>
>> static const char *guid_to_name(const efi_guid_t *guid)
>> {
>> struct guid_name *entry;
>>
>> for (entry = guid_name; entry->name; entry++) {
>> if (!guidcmp(guid, &entry->guid))
>> return entry->name;
>> }
>>
>> return NULL;
>> }
>>
>>
>>
>> Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
>>
>>
>>
>>
>>
>> We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
>>
>>
>>
>> Indeed. There is certainly value in both approaches.
>>
>>
>>
>> Regards,
>>
>> Simon
>>
>>
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: Tuesday, March 23, 2021 10:00 AM
>> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> +Ron Minnich +Paul Isaac's
>>
>>
>>
>> Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
>>
>>
>>
>> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> I propose we cover the topic at the next Trusted Substrate zoom call on April 8th 4pm CET.
>>
>>
>>
>> The agenda:
>>
>> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
>>
>> runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
>>
>>
>>
>> For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
>>
>> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
>>
>> This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
>>
>> HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
>>
>>
>>
>> There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
>>
>> I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
>>
>>
>>
>> Requirements (to be validated):
>>
>> - ACPI and DT hardware descriptions.
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
>>
>> - at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
>>
>> - support secure world device assignment
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>>
>>
>> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
>>
>> Hi,
>>
>> Can I suggest using bloblist for this instead? It is lightweight,
>> easier to parse, doesn't have GUIDs and is already used within U-Boot
>> for passing info between SPL/U-Boot, etc.
>>
>> Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
>> Header file describes the format:
>> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>>
>> Full set of unit tests:
>> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>>
>> Regards,
>> Simon
>>
>> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org> wrote:
>> >
>> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
>> >
>> > standardization is very much welcomed here and need to accommodate a very
>> > diverse set of situations.
>> > For example, TEE OS may need to pass memory reservations to BL33 or
>> > "capture" a device for the secure world.
>> >
>> > I have observed a number of architectures:
>> > 1) pass information from BLx to BLy in the form of a specific object
>> > 2) BLx called by BLy by a platform specific SMC to get information
>> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
>> > fixups
>> >
>> > I also imagined a standardized "broadcast" FF-A call so that any firmware
>> > element can either provide information or "do something".
>> >
>> > My understanding of your proposal is about standardizing on architecture 1)
>> > with the HOB format.
>> >
>> > The advantage of the HOB is simplicity but it may be difficult to implement
>> > schemes such as pruning a DT because device assignment in the secure world.
>> >
>> > In any case, it looks feasible to have TF-A and OP-TEE complement the list
>> > of HOBs to pass information downstream (the bootflow).
>> >
>> > It would be good to start with building the comprehensive list of
>> > information that need to be conveyed between firmware elements:
>> >
>> > information. | authoritative entity | reporting entity | information
>> > exchanged:
>> > dram | TFA | TFA |
>> > <format to be detailed, NUMA topology to build the SRAT table or DT
>> > equivalent?>
>> > PSCI | SCP | TFA? |
>> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
>> > secure SRAM | TFA. | TFA. |
>> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
>> > other? | |
>> > |
>> >
>> > Cheers
>> >
>> > FF
>> >
>> >
>> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
>> > tf-a(a)lists.trustedfirmware.org> wrote:
>> >
>> > > Hello Folks,
>> > >
>> > >
>> > >
>> > > I'm emailing to start an open discussion about the adoption of a concept
>> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
>> > > Framework Architecture (FFA). This is something that is a pretty major
>> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
>> > > designed to enable a broad range of highly configurable datacenter
>> > > platforms.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > What is a HOB (Background)?
>> > >
>> > > ---------------------------
>> > >
>> > > UEFI PI spec describes a particular definition for how HOB may be used for
>> > > transitioning between the PEI and DXE boot phases, which is a good
>> > > reference point for this discussion, but not necessarily the exact solution
>> > > appropriate for TF-A.
>> > >
>> > >
>> > >
>> > > A HOB is simply a dynamically generated data structure passed in between
>> > > two boot phases. This is information that was obtained through discovery
>> > > and needs to be passed forward to the next boot phase *once*, with no API
>> > > needed to call back (e.g. no call back into previous firmware phase is
>> > > needed to fetch this information at run-time - it is simply passed one time
>> > > during boot).
>> > >
>> > >
>> > >
>> > > There may be one or more HOBs passed in between boot phases. If there are
>> > > more than one HOB that needs to be passed, this can be in a form of a "HOB
>> > > table", which (for example) could be a UUID indexed array of pointers to
>> > > HOB structures, used to locate a HOB of interest (based on UUID). In such
>> > > cases, instead of passing a single HOB, the boot phases may rely on passing
>> > > the pointer to the HOB table.
>> > >
>> > >
>> > >
>> > > This has been extremely useful concept to employ on highly configurable
>> > > systems that must rely on flexible discovery mechanisms to initialize and
>> > > boot the system. This is especially helpful when you have multiple
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Why do we need HOBs in TF-A?:
>> > >
>> > > -----------------------------
>> > >
>> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
>> > > a way that is SoC specific *but* platform agnostic. This means that a
>> > > single ARM SoC that a SiP may deliver to customers may provide a single
>> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
>> > > range of platform designs and configurations in order to boot a platform
>> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
>> > > achieve this, the platform configuration must be *discovered* instead of
>> > > statically compiled as it is today in TF-A via device tree based
>> > > enumeration. The mechanisms of discovery may differ broadly depending on
>> > > the relevant industry standard, or in some cases may have rely on SiP
>> > > specific discovery flows.
>> > >
>> > >
>> > >
>> > > For example: On server systems that support a broad range DIMM memory
>> > > population/topologies, all the necessary information required to boot is
>> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
>> > > I2C bus. Leveraging the SPD bus, may platform variants could be supported
>> > > with a single TF-A binary. Not only is this information required to
>> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
>> > > phases will also need this SPD info to construct a system physical address
>> > > map and properly initialize the MMU based on the memory present, and where
>> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
>> > > need to generate standard firmware tables to the operating systems, such as
>> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
>> > > SRAT, even NFIT if NVDIMM's are present).
>> > >
>> > >
>> > >
>> > > In short, it all starts with a standardized or vendor specific discovery
>> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
>> > > information to the next boot stages (e.g. BL31/BL32/BL33).
>> > >
>> > >
>> > >
>> > > Today, every HOB may be a vendor specific structure, but in the future
>> > > there may be benefit of defining standard HOBs. This may be useful for
>> > > memory discovery, passing the system physical address map, enabling TPM
>> > > measured boot, and potentially many other common HOB use-cases.
>> > >
>> > >
>> > >
>> > > It would be extremely beneficial to the datacenter market segment if the
>> > > TF-A community would adopt this concept of information passing between all
>> > > boot phases as opposed to rely solely on device tree enumeration. This is
>> > > not intended to replace device tree, rather intended as an alternative way
>> > > to describe the info that must be discovered and dynamically generated.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Conclusion:
>> > >
>> > > -----------
>> > >
>> > > We are proposing that the TF-A community begin pursuing the adoption of
>> > > HOBs as a mechanism used for information exchange between each boot stage
>> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
>> > > want to explore standardizing some HOB structures for the BL33 phase (e.g.
>> > > UEFI HOB structures), but initially would like to agree on this being a
>> > > useful mechanism used to pass information between each boot stage.
>> > >
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > --Harb
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > --
>> > > TF-A mailing list
>> > > TF-A(a)lists.trustedfirmware.org
>> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> > >
>> >
>> >
>> > --
>> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
>> > T: +33.67221.6485
>> > francois.ozog(a)linaro.org | Skype: ffozog
>> > _______________________________________________
>> > boot-architecture mailing list
>> > boot-architecture(a)lists.linaro.org
>> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
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Hi,
I tried to summarize the discussions in the previous TF-A tech forum regarding the proposal to adopt Hand-off Blocks (HOBs) for passing information along the boot chain. I am certain I could not capture all suggestions/concerns brought up during the call. I apologize if I missed and/or misinterpreted any comments and would appreciate it if everyone could share their thoughts in response to this email thread.
The idea is to share information to other boot phases:
> Dynamic information: Created during runtime. Shared in the form of a chain of blobs(built as a linked list of C structure objects i.e., HOB list).
> Static information: Known at compile time. Historically, shared through the use of Device Tree/ACPI tables
Both the above requirements are common in many ecosystems and need to co-exist.
There are broadly 3 problems to solve:
1. Format of HOB structures: It looks like the consensus is that we could use existing mechanisms for this (BL_AUX_PARAM in TF-A or bloblist in u-boot).
2. Identification of HOB list entries: There is a debate about whether tags would suffice or if the HOB list producer and consumer would depend on UUID/GUIDs for identifying a specific HOB structure. Another suggestion was to use a hybrid approach. Reserve a single tag ID for identifying/constructing a HOB structure that further leverages UUID based identifier. This way, the generic HOB list doesn't need to support UUIDs and can work with tags.
3. The design contract for the static interface between two boot phases: The problem at hand is whether to pass a pointer to a HOB list or a device tree blob through the general-purpose registers for configuration hand-off between two boot phases. Some proposals that came up:
> Proposal 1: Always pass a pointer to the device tree blob through the GP register and capture the pointer to the HOB list as a property of a node that is uniquely identifiable by the downstream boot phase. This needs to define a device tree binding such that producer and consumer agree on the information passed.
> Proposal 2: Pass a pointer to a generic container through the GP register that can be interpreted appropriately by both boot loaders(i.e., producer and consumer of the boot info). This container can either be a dtb or a HOB list which can be simply inferred by checking for a magic header that indicates if the buffer appears to be a flattened device tree.
> One another concern that was brought up offline is to make sure we don't break current design contracts between various boot loader phases in TF-A. Many of the general-purpose registers have a designated purpose such as to share configurations between BL images( such as firmware config dtb, SoC config dtb, Non trusted firmware config dtb, memory layout, entry point info, etc.).
If I am not mistaken, a single design may not fit the needs of every segment(client, Infra, embedded) and the forum is open to solutions tailored for individual segments. Joanna will be sending a follow up email with more information about future TF-A tech forums that serves as a platform for further discussions.
Thanks,
Madhukar
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A
Sent: Sunday, May 16, 2021 5:19 AM
To: Okash Khawaja <okash.khawaja(a)gmail.com>; Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; Ed Stuber <edstuber(a)amperecomputing.com>; Arjun Khare <akhare(a)amperecomputing.com>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Moe Ammar <moe(a)amperecomputing.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Apologies I failed with the recording. Manish/Madhu will reply early next week with the slides and some notes to help with a follow up session which we hope to hold this Thursday. Invite and agenda will also be sent out early next week.
Thanks
Joanna
On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi,
Do we have slides and video from last week's discussion?
Thanks,
Okash
On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> Thanks for the idea. I am still not completely sure what benefit UUID provides to an open project. I'd like to propose something different, more in the spirit of open collaboration. I also worry that the word 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring closed-source firmware and the continued decline of open-source projects. It really should not be.
>
> So I suggest: Use simple integer IDs and reserve some area for 'private' use. If you want to collaborate across projects outside your company, you either need to allocate a 'public' ID or agree privately between the parties which private ID to use.
>
> This means that the default and easiest option is for collaboration and a public ID, with private ones (whose purpose may be secret) reserved just for private use.
>
> Regards,
> Simon
>
> On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hey Folks,
>>
>> We wanted to put out a middle-ground proposal to help guide the discussion on the call tomorrow.
>>
>>
>>
>> A proposal that we have been discussing offline involves reserving a single tag ID for the purpose of construction UEFI PI HOB List structure, and that tag would be used to identify a HOB-specific structure that does leverage UUID based identifier. This will eliminate the burden of having to support UUID as the tag, and this enables projects that require UUID based identifiers for the broad range of HOB structures that need to be produced during the booting of the platform. Once we have a tag for a HOB list, this will enable various HOB producers that can add/extend the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other side (i.e. whatever the BL33 image is booting on that platform).
>>
>>
>>
>> Essentially, the idea is if someone would like to support HOB structures in a standard way using TF-A, they would wrap it up in a BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we identify the structure as a HOB list is with this new reserved tag.
>>
>>
>>
>> Hopefully that makes sense and less contentious. Look forward to discuss this further on the call.
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Sent: Friday, April 30, 2021 8:14 AM
>> To: François Ozog <francois.ozog(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi All,
>>
>>
>>
>> Please find invite for next TF-A Tech Forum session to continue our discussions on HOB implementation, feel free to forward it to others.
>>
>>
>>
>> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
>>
>>
>>
>> Agenda:
>>
>> Discussion Session: Static and Dynamic Information Handling in TF-A
>>
>> Lead by Manish Pandey and Madhukar Pappireddy
>>
>> · There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
>>
>> The requirement is two-fold:
>>
>> 1. Passing static information(config files)
>>
>> 2. Passing dynamic information (Hob list)
>>
>> In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
>>
>>
>>
>> The two specific item which we would like to discuss are:
>>
>> 1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
>>
>> 2. Standardization on Physical register use to pass base of HoB data structure.
>>
>> References:
>>
>> [1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
>>
>> [2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
>>
>>
>>
>> Thanks
>>
>>
>>
>> Joanna
>>
>>
>>
>> You have been invited to the following event.
>>
>> TF-A Tech Forum
>>
>> When
>>
>> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
>>
>> Calendar
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> Who
>>
>> •
>>
>> Bill Fletcher- creator
>>
>> •
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> more details »
>>
>>
>>
>> We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
>>
>>
>>
>> Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
>>
>>
>>
>> Trusted Firmware is inviting you to a scheduled Zoom meeting.
>>
>>
>>
>> Join Zoom Meeting
>>
>> https://zoom.us/j/9159704974
>>
>>
>>
>> Meeting ID: 915 970 4974
>>
>>
>>
>> One tap mobile
>>
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>>
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>>
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>>
>> Find your local number: https://zoom.us/u/ad27hc6t7h
>>
>>
>>
>> ________________________________
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: 08 April 2021 16:50
>> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi
>>
>>
>>
>> here is the meeting recording:
>>
>> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%z
>>
>>
>>
>> I am really sorry about the confusion related to the meeting time. I have now understood: the Collaborate portal uses a specific calendar which is tied to US/Chicago timezone while the actual Google Calendar is tied to Central Europe timezone. I am going to drop the Collaborate portal and use a shared Google calendar (it should be visible on the trusted-substrate.org page).
>>
>>
>>
>> I'll try to summarize what I learnt and highlight my view on what can be next steps in a future mail.
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
>>
>>
>>
>> To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
>>
>>
>>
>> The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
>>
>>
>>
>> One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
>>
>>
>>
>> Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
>>
>>
>>
>> Looking forward to having further discussions on zoom call today.
>>
>>
>>
>> Thanks
>>
>> Manish P
>>
>>
>>
>> ________________________________
>>
>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
>> Sent: 25 March 2021 02:43
>> To: Simon Glass <sjg(a)chromium.org>
>> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
>>
>>
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>>
>>
>> It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
>>
>>
>>
>> I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
>>
>>
>>
>> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi Harb,
>>
>>
>>
>> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hello Folks,
>>
>> Appreciate the feedback and replies on this. Glad to see that there is interest in this topic.
>>
>>
>>
>> I try to address the comments/feedback from Francois and Simon below….
>>
>>
>>
>> @François Ozog – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
>>
>>
>>
>> Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
>>
>>
>>
>> The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
>>
>>
>>
>> Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
>>
>> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
>> “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
>>
>>
>>
>> Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
>>
>>
>>
>> To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
>>
>>
>>
>> I understand the versatility of DT, but I see two major problems with DT:
>>
>> DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
>> DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
>>
>>
>>
>> I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
>>
>>
>>
>> Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
>>
>>
>>
>> Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
>>
>>
>>
>> @Simon Glass - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
>>
>>
>>
>> That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
>>
>>
>>
>> The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
>>
>>
>>
>> I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
>>
>>
>>
>> True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
>>
>>
>>
>> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
>> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
>> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
>>
>> (etc.)
>>
>>
>>
>> static struct guid_name {
>> efi_guid_t guid;
>> const char *name;
>> } guid_name[] = {
>> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
>> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
>> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
>> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
>> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
>> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
>>
>> (never figured out what those two are)
>>
>>
>> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
>> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
>> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
>> { {}, "zero-guid" },
>> {}
>> };
>>
>> static const char *guid_to_name(const efi_guid_t *guid)
>> {
>> struct guid_name *entry;
>>
>> for (entry = guid_name; entry->name; entry++) {
>> if (!guidcmp(guid, &entry->guid))
>> return entry->name;
>> }
>>
>> return NULL;
>> }
>>
>>
>>
>> Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
>>
>>
>>
>>
>>
>> We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
>>
>>
>>
>> Indeed. There is certainly value in both approaches.
>>
>>
>>
>> Regards,
>>
>> Simon
>>
>>
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: Tuesday, March 23, 2021 10:00 AM
>> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> +Ron Minnich +Paul Isaac's
>>
>>
>>
>> Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
>>
>>
>>
>> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> I propose we cover the topic at the next Trusted Substrate zoom call on April 8th 4pm CET.
>>
>>
>>
>> The agenda:
>>
>> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
>>
>> runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
>>
>>
>>
>> For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
>>
>> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
>>
>> This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
>>
>> HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
>>
>>
>>
>> There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
>>
>> I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
>>
>>
>>
>> Requirements (to be validated):
>>
>> - ACPI and DT hardware descriptions.
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
>>
>> - at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
>>
>> - support secure world device assignment
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>>
>>
>> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
>>
>> Hi,
>>
>> Can I suggest using bloblist for this instead? It is lightweight,
>> easier to parse, doesn't have GUIDs and is already used within U-Boot
>> for passing info between SPL/U-Boot, etc.
>>
>> Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
>> Header file describes the format:
>> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>>
>> Full set of unit tests:
>> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>>
>> Regards,
>> Simon
>>
>> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org> wrote:
>> >
>> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
>> >
>> > standardization is very much welcomed here and need to accommodate a very
>> > diverse set of situations.
>> > For example, TEE OS may need to pass memory reservations to BL33 or
>> > "capture" a device for the secure world.
>> >
>> > I have observed a number of architectures:
>> > 1) pass information from BLx to BLy in the form of a specific object
>> > 2) BLx called by BLy by a platform specific SMC to get information
>> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
>> > fixups
>> >
>> > I also imagined a standardized "broadcast" FF-A call so that any firmware
>> > element can either provide information or "do something".
>> >
>> > My understanding of your proposal is about standardizing on architecture 1)
>> > with the HOB format.
>> >
>> > The advantage of the HOB is simplicity but it may be difficult to implement
>> > schemes such as pruning a DT because device assignment in the secure world.
>> >
>> > In any case, it looks feasible to have TF-A and OP-TEE complement the list
>> > of HOBs to pass information downstream (the bootflow).
>> >
>> > It would be good to start with building the comprehensive list of
>> > information that need to be conveyed between firmware elements:
>> >
>> > information. | authoritative entity | reporting entity | information
>> > exchanged:
>> > dram | TFA | TFA |
>> > <format to be detailed, NUMA topology to build the SRAT table or DT
>> > equivalent?>
>> > PSCI | SCP | TFA? |
>> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
>> > secure SRAM | TFA. | TFA. |
>> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
>> > other? | |
>> > |
>> >
>> > Cheers
>> >
>> > FF
>> >
>> >
>> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
>> > tf-a(a)lists.trustedfirmware.org> wrote:
>> >
>> > > Hello Folks,
>> > >
>> > >
>> > >
>> > > I'm emailing to start an open discussion about the adoption of a concept
>> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
>> > > Framework Architecture (FFA). This is something that is a pretty major
>> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
>> > > designed to enable a broad range of highly configurable datacenter
>> > > platforms.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > What is a HOB (Background)?
>> > >
>> > > ---------------------------
>> > >
>> > > UEFI PI spec describes a particular definition for how HOB may be used for
>> > > transitioning between the PEI and DXE boot phases, which is a good
>> > > reference point for this discussion, but not necessarily the exact solution
>> > > appropriate for TF-A.
>> > >
>> > >
>> > >
>> > > A HOB is simply a dynamically generated data structure passed in between
>> > > two boot phases. This is information that was obtained through discovery
>> > > and needs to be passed forward to the next boot phase *once*, with no API
>> > > needed to call back (e.g. no call back into previous firmware phase is
>> > > needed to fetch this information at run-time - it is simply passed one time
>> > > during boot).
>> > >
>> > >
>> > >
>> > > There may be one or more HOBs passed in between boot phases. If there are
>> > > more than one HOB that needs to be passed, this can be in a form of a "HOB
>> > > table", which (for example) could be a UUID indexed array of pointers to
>> > > HOB structures, used to locate a HOB of interest (based on UUID). In such
>> > > cases, instead of passing a single HOB, the boot phases may rely on passing
>> > > the pointer to the HOB table.
>> > >
>> > >
>> > >
>> > > This has been extremely useful concept to employ on highly configurable
>> > > systems that must rely on flexible discovery mechanisms to initialize and
>> > > boot the system. This is especially helpful when you have multiple
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Why do we need HOBs in TF-A?:
>> > >
>> > > -----------------------------
>> > >
>> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
>> > > a way that is SoC specific *but* platform agnostic. This means that a
>> > > single ARM SoC that a SiP may deliver to customers may provide a single
>> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
>> > > range of platform designs and configurations in order to boot a platform
>> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
>> > > achieve this, the platform configuration must be *discovered* instead of
>> > > statically compiled as it is today in TF-A via device tree based
>> > > enumeration. The mechanisms of discovery may differ broadly depending on
>> > > the relevant industry standard, or in some cases may have rely on SiP
>> > > specific discovery flows.
>> > >
>> > >
>> > >
>> > > For example: On server systems that support a broad range DIMM memory
>> > > population/topologies, all the necessary information required to boot is
>> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
>> > > I2C bus. Leveraging the SPD bus, may platform variants could be supported
>> > > with a single TF-A binary. Not only is this information required to
>> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
>> > > phases will also need this SPD info to construct a system physical address
>> > > map and properly initialize the MMU based on the memory present, and where
>> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
>> > > need to generate standard firmware tables to the operating systems, such as
>> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
>> > > SRAT, even NFIT if NVDIMM's are present).
>> > >
>> > >
>> > >
>> > > In short, it all starts with a standardized or vendor specific discovery
>> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
>> > > information to the next boot stages (e.g. BL31/BL32/BL33).
>> > >
>> > >
>> > >
>> > > Today, every HOB may be a vendor specific structure, but in the future
>> > > there may be benefit of defining standard HOBs. This may be useful for
>> > > memory discovery, passing the system physical address map, enabling TPM
>> > > measured boot, and potentially many other common HOB use-cases.
>> > >
>> > >
>> > >
>> > > It would be extremely beneficial to the datacenter market segment if the
>> > > TF-A community would adopt this concept of information passing between all
>> > > boot phases as opposed to rely solely on device tree enumeration. This is
>> > > not intended to replace device tree, rather intended as an alternative way
>> > > to describe the info that must be discovered and dynamically generated.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Conclusion:
>> > >
>> > > -----------
>> > >
>> > > We are proposing that the TF-A community begin pursuing the adoption of
>> > > HOBs as a mechanism used for information exchange between each boot stage
>> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
>> > > want to explore standardizing some HOB structures for the BL33 phase (e.g.
>> > > UEFI HOB structures), but initially would like to agree on this being a
>> > > useful mechanism used to pass information between each boot stage.
>> > >
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > --Harb
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > --
>> > > TF-A mailing list
>> > > TF-A(a)lists.trustedfirmware.org
>> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> > >
>> >
>> >
>> > --
>> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
>> > T: +33.67221.6485
>> > francois.ozog(a)linaro.org | Skype: ffozog
>> > _______________________________________________
>> > boot-architecture mailing list
>> > boot-architecture(a)lists.linaro.org
>> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
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TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Apologies I failed with the recording. Manish/Madhu will reply early next week with the slides and some notes to help with a follow up session which we hope to hold this Thursday. Invite and agenda will also be sent out early next week.
Thanks
Joanna
On 14/05/2021, 13:30, "TF-A on behalf of Okash Khawaja via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi,
Do we have slides and video from last week's discussion?
Thanks,
Okash
On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> Thanks for the idea. I am still not completely sure what benefit UUID provides to an open project. I'd like to propose something different, more in the spirit of open collaboration. I also worry that the word 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring closed-source firmware and the continued decline of open-source projects. It really should not be.
>
> So I suggest: Use simple integer IDs and reserve some area for 'private' use. If you want to collaborate across projects outside your company, you either need to allocate a 'public' ID or agree privately between the parties which private ID to use.
>
> This means that the default and easiest option is for collaboration and a public ID, with private ones (whose purpose may be secret) reserved just for private use.
>
> Regards,
> Simon
>
> On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hey Folks,
>>
>> We wanted to put out a middle-ground proposal to help guide the discussion on the call tomorrow.
>>
>>
>>
>> A proposal that we have been discussing offline involves reserving a single tag ID for the purpose of construction UEFI PI HOB List structure, and that tag would be used to identify a HOB-specific structure that does leverage UUID based identifier. This will eliminate the burden of having to support UUID as the tag, and this enables projects that require UUID based identifiers for the broad range of HOB structures that need to be produced during the booting of the platform. Once we have a tag for a HOB list, this will enable various HOB producers that can add/extend the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other side (i.e. whatever the BL33 image is booting on that platform).
>>
>>
>>
>> Essentially, the idea is if someone would like to support HOB structures in a standard way using TF-A, they would wrap it up in a BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we identify the structure as a HOB list is with this new reserved tag.
>>
>>
>>
>> Hopefully that makes sense and less contentious. Look forward to discuss this further on the call.
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Sent: Friday, April 30, 2021 8:14 AM
>> To: François Ozog <francois.ozog(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi All,
>>
>>
>>
>> Please find invite for next TF-A Tech Forum session to continue our discussions on HOB implementation, feel free to forward it to others.
>>
>>
>>
>> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
>>
>>
>>
>> Agenda:
>>
>> Discussion Session: Static and Dynamic Information Handling in TF-A
>>
>> Lead by Manish Pandey and Madhukar Pappireddy
>>
>> · There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
>>
>> The requirement is two-fold:
>>
>> 1. Passing static information(config files)
>>
>> 2. Passing dynamic information (Hob list)
>>
>> In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
>>
>>
>>
>> The two specific item which we would like to discuss are:
>>
>> 1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
>>
>> 2. Standardization on Physical register use to pass base of HoB data structure.
>>
>> References:
>>
>> [1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
>>
>> [2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
>>
>>
>>
>> Thanks
>>
>>
>>
>> Joanna
>>
>>
>>
>> You have been invited to the following event.
>>
>> TF-A Tech Forum
>>
>> When
>>
>> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
>>
>> Calendar
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> Who
>>
>> •
>>
>> Bill Fletcher- creator
>>
>> •
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> more details »
>>
>>
>>
>> We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
>>
>>
>>
>> Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
>>
>>
>>
>> Trusted Firmware is inviting you to a scheduled Zoom meeting.
>>
>>
>>
>> Join Zoom Meeting
>>
>> https://zoom.us/j/9159704974
>>
>>
>>
>> Meeting ID: 915 970 4974
>>
>>
>>
>> One tap mobile
>>
>> +16465588656,,9159704974# US (New York)
>>
>> +16699009128,,9159704974# US (San Jose)
>>
>>
>>
>> Dial by your location
>>
>> +1 646 558 8656 US (New York)
>>
>> +1 669 900 9128 US (San Jose)
>>
>> 877 853 5247 US Toll-free
>>
>> 888 788 0099 US Toll-free
>>
>> Meeting ID: 915 970 4974
>>
>> Find your local number: https://zoom.us/u/ad27hc6t7h
>>
>>
>>
>> ________________________________
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: 08 April 2021 16:50
>> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi
>>
>>
>>
>> here is the meeting recording:
>>
>> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%z
>>
>>
>>
>> I am really sorry about the confusion related to the meeting time. I have now understood: the Collaborate portal uses a specific calendar which is tied to US/Chicago timezone while the actual Google Calendar is tied to Central Europe timezone. I am going to drop the Collaborate portal and use a shared Google calendar (it should be visible on the trusted-substrate.org page).
>>
>>
>>
>> I'll try to summarize what I learnt and highlight my view on what can be next steps in a future mail.
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
>>
>>
>>
>> To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
>>
>>
>>
>> The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
>>
>>
>>
>> One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
>>
>>
>>
>> Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
>>
>>
>>
>> Looking forward to having further discussions on zoom call today.
>>
>>
>>
>> Thanks
>>
>> Manish P
>>
>>
>>
>> ________________________________
>>
>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
>> Sent: 25 March 2021 02:43
>> To: Simon Glass <sjg(a)chromium.org>
>> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
>>
>>
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>>
>>
>> It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
>>
>>
>>
>> I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
>>
>>
>>
>> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi Harb,
>>
>>
>>
>> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hello Folks,
>>
>> Appreciate the feedback and replies on this. Glad to see that there is interest in this topic.
>>
>>
>>
>> I try to address the comments/feedback from Francois and Simon below….
>>
>>
>>
>> @François Ozog – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
>>
>>
>>
>> Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
>>
>>
>>
>> The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
>>
>>
>>
>> Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
>>
>> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
>> “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
>>
>>
>>
>> Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
>>
>>
>>
>> To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
>>
>>
>>
>> I understand the versatility of DT, but I see two major problems with DT:
>>
>> DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
>> DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
>>
>>
>>
>> I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
>>
>>
>>
>> Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
>>
>>
>>
>> Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
>>
>>
>>
>> @Simon Glass - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
>>
>>
>>
>> That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
>>
>>
>>
>> The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
>>
>>
>>
>> I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
>>
>>
>>
>> True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
>>
>>
>>
>> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
>> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
>> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
>>
>> (etc.)
>>
>>
>>
>> static struct guid_name {
>> efi_guid_t guid;
>> const char *name;
>> } guid_name[] = {
>> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
>> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
>> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
>> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
>> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
>> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
>>
>> (never figured out what those two are)
>>
>>
>> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
>> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
>> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
>> { {}, "zero-guid" },
>> {}
>> };
>>
>> static const char *guid_to_name(const efi_guid_t *guid)
>> {
>> struct guid_name *entry;
>>
>> for (entry = guid_name; entry->name; entry++) {
>> if (!guidcmp(guid, &entry->guid))
>> return entry->name;
>> }
>>
>> return NULL;
>> }
>>
>>
>>
>> Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
>>
>>
>>
>>
>>
>> We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
>>
>>
>>
>> Indeed. There is certainly value in both approaches.
>>
>>
>>
>> Regards,
>>
>> Simon
>>
>>
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: Tuesday, March 23, 2021 10:00 AM
>> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> +Ron Minnich +Paul Isaac's
>>
>>
>>
>> Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
>>
>>
>>
>> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> I propose we cover the topic at the next Trusted Substrate zoom call on April 8th 4pm CET.
>>
>>
>>
>> The agenda:
>>
>> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
>>
>> runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
>>
>>
>>
>> For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
>>
>> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
>>
>> This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
>>
>> HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
>>
>>
>>
>> There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
>>
>> I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
>>
>>
>>
>> Requirements (to be validated):
>>
>> - ACPI and DT hardware descriptions.
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
>>
>> - at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
>>
>> - support secure world device assignment
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>>
>>
>> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
>>
>> Hi,
>>
>> Can I suggest using bloblist for this instead? It is lightweight,
>> easier to parse, doesn't have GUIDs and is already used within U-Boot
>> for passing info between SPL/U-Boot, etc.
>>
>> Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
>> Header file describes the format:
>> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>>
>> Full set of unit tests:
>> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>>
>> Regards,
>> Simon
>>
>> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org> wrote:
>> >
>> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
>> >
>> > standardization is very much welcomed here and need to accommodate a very
>> > diverse set of situations.
>> > For example, TEE OS may need to pass memory reservations to BL33 or
>> > "capture" a device for the secure world.
>> >
>> > I have observed a number of architectures:
>> > 1) pass information from BLx to BLy in the form of a specific object
>> > 2) BLx called by BLy by a platform specific SMC to get information
>> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
>> > fixups
>> >
>> > I also imagined a standardized "broadcast" FF-A call so that any firmware
>> > element can either provide information or "do something".
>> >
>> > My understanding of your proposal is about standardizing on architecture 1)
>> > with the HOB format.
>> >
>> > The advantage of the HOB is simplicity but it may be difficult to implement
>> > schemes such as pruning a DT because device assignment in the secure world.
>> >
>> > In any case, it looks feasible to have TF-A and OP-TEE complement the list
>> > of HOBs to pass information downstream (the bootflow).
>> >
>> > It would be good to start with building the comprehensive list of
>> > information that need to be conveyed between firmware elements:
>> >
>> > information. | authoritative entity | reporting entity | information
>> > exchanged:
>> > dram | TFA | TFA |
>> > <format to be detailed, NUMA topology to build the SRAT table or DT
>> > equivalent?>
>> > PSCI | SCP | TFA? |
>> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
>> > secure SRAM | TFA. | TFA. |
>> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
>> > other? | |
>> > |
>> >
>> > Cheers
>> >
>> > FF
>> >
>> >
>> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
>> > tf-a(a)lists.trustedfirmware.org> wrote:
>> >
>> > > Hello Folks,
>> > >
>> > >
>> > >
>> > > I'm emailing to start an open discussion about the adoption of a concept
>> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
>> > > Framework Architecture (FFA). This is something that is a pretty major
>> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
>> > > designed to enable a broad range of highly configurable datacenter
>> > > platforms.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > What is a HOB (Background)?
>> > >
>> > > ---------------------------
>> > >
>> > > UEFI PI spec describes a particular definition for how HOB may be used for
>> > > transitioning between the PEI and DXE boot phases, which is a good
>> > > reference point for this discussion, but not necessarily the exact solution
>> > > appropriate for TF-A.
>> > >
>> > >
>> > >
>> > > A HOB is simply a dynamically generated data structure passed in between
>> > > two boot phases. This is information that was obtained through discovery
>> > > and needs to be passed forward to the next boot phase *once*, with no API
>> > > needed to call back (e.g. no call back into previous firmware phase is
>> > > needed to fetch this information at run-time - it is simply passed one time
>> > > during boot).
>> > >
>> > >
>> > >
>> > > There may be one or more HOBs passed in between boot phases. If there are
>> > > more than one HOB that needs to be passed, this can be in a form of a "HOB
>> > > table", which (for example) could be a UUID indexed array of pointers to
>> > > HOB structures, used to locate a HOB of interest (based on UUID). In such
>> > > cases, instead of passing a single HOB, the boot phases may rely on passing
>> > > the pointer to the HOB table.
>> > >
>> > >
>> > >
>> > > This has been extremely useful concept to employ on highly configurable
>> > > systems that must rely on flexible discovery mechanisms to initialize and
>> > > boot the system. This is especially helpful when you have multiple
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Why do we need HOBs in TF-A?:
>> > >
>> > > -----------------------------
>> > >
>> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
>> > > a way that is SoC specific *but* platform agnostic. This means that a
>> > > single ARM SoC that a SiP may deliver to customers may provide a single
>> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
>> > > range of platform designs and configurations in order to boot a platform
>> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
>> > > achieve this, the platform configuration must be *discovered* instead of
>> > > statically compiled as it is today in TF-A via device tree based
>> > > enumeration. The mechanisms of discovery may differ broadly depending on
>> > > the relevant industry standard, or in some cases may have rely on SiP
>> > > specific discovery flows.
>> > >
>> > >
>> > >
>> > > For example: On server systems that support a broad range DIMM memory
>> > > population/topologies, all the necessary information required to boot is
>> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
>> > > I2C bus. Leveraging the SPD bus, may platform variants could be supported
>> > > with a single TF-A binary. Not only is this information required to
>> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
>> > > phases will also need this SPD info to construct a system physical address
>> > > map and properly initialize the MMU based on the memory present, and where
>> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
>> > > need to generate standard firmware tables to the operating systems, such as
>> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
>> > > SRAT, even NFIT if NVDIMM's are present).
>> > >
>> > >
>> > >
>> > > In short, it all starts with a standardized or vendor specific discovery
>> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
>> > > information to the next boot stages (e.g. BL31/BL32/BL33).
>> > >
>> > >
>> > >
>> > > Today, every HOB may be a vendor specific structure, but in the future
>> > > there may be benefit of defining standard HOBs. This may be useful for
>> > > memory discovery, passing the system physical address map, enabling TPM
>> > > measured boot, and potentially many other common HOB use-cases.
>> > >
>> > >
>> > >
>> > > It would be extremely beneficial to the datacenter market segment if the
>> > > TF-A community would adopt this concept of information passing between all
>> > > boot phases as opposed to rely solely on device tree enumeration. This is
>> > > not intended to replace device tree, rather intended as an alternative way
>> > > to describe the info that must be discovered and dynamically generated.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Conclusion:
>> > >
>> > > -----------
>> > >
>> > > We are proposing that the TF-A community begin pursuing the adoption of
>> > > HOBs as a mechanism used for information exchange between each boot stage
>> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
>> > > want to explore standardizing some HOB structures for the BL33 phase (e.g.
>> > > UEFI HOB structures), but initially would like to agree on this being a
>> > > useful mechanism used to pass information between each boot stage.
>> > >
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > --Harb
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > --
>> > > TF-A mailing list
>> > > TF-A(a)lists.trustedfirmware.org
>> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> > >
>> >
>> >
>> > --
>> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
>> > T: +33.67221.6485
>> > francois.ozog(a)linaro.org | Skype: ffozog
>> > _______________________________________________
>> > boot-architecture mailing list
>> > boot-architecture(a)lists.linaro.org
>> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
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Hi Okash,
My understanding is that the NS world must call PSCI_MEM_PROTECT_CHECK_RANGE and PSCI_MEM_PROTECT before passing the buffer to the S world. So, I believe the check in the code is correct.
The spec guarantees that the memory range passed with this SMC will be cleared before executing a system reset.
This statement from the spec is confusing - " When MEM_PROTECT is called, the implementation must ensure that all volatile memory that is accessible by the caller is overwritten on the following boot". How can the implementation know the memory accessible by the caller in the first place? I feel this creates an unwanted dependency - EL3 needs to understand memory requirements for all NS clients.
I would like to believe that the implementation is only aware of a memory range registered by a caller via the MEM_PROTECT SMC call and so clears only this range before a system reset.
-Varun
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Okash Khawaja via TF-A
Sent: Wednesday, May 5, 2021 5:10 PM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] MEM_PROTECT for secure world?
External email: Use caution opening links or attachments
Hi,
As a PSCI call, MEM_PROTECT which is used to protect against cold reboot attack, can't be called from TZ-secure. In a situation where at run time, HLOS in NS-EL1 transfers some buffer that it owns, to a secure partition then secure partition can't call MEM_PROTECT because psci_smc_handler will return SMC_UNK if the caller is secure.
Should MEM_PROTECT be available to TZ-secure as well?
Thanks,
Okash
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https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.tru…
Hi,
Do we have slides and video from last week's discussion?
Thanks,
Okash
On Wed, May 5, 2021 at 11:52 PM Simon Glass via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> Thanks for the idea. I am still not completely sure what benefit UUID provides to an open project. I'd like to propose something different, more in the spirit of open collaboration. I also worry that the word 'standard' seems to be a synonym for UUIDs, UEFI, etc., i.e. enabling/preferring closed-source firmware and the continued decline of open-source projects. It really should not be.
>
> So I suggest: Use simple integer IDs and reserve some area for 'private' use. If you want to collaborate across projects outside your company, you either need to allocate a 'public' ID or agree privately between the parties which private ID to use.
>
> This means that the default and easiest option is for collaboration and a public ID, with private ones (whose purpose may be secret) reserved just for private use.
>
> Regards,
> Simon
>
> On Wed, 5 May 2021 at 11:42, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hey Folks,
>>
>> We wanted to put out a middle-ground proposal to help guide the discussion on the call tomorrow.
>>
>>
>>
>> A proposal that we have been discussing offline involves reserving a single tag ID for the purpose of construction UEFI PI HOB List structure, and that tag would be used to identify a HOB-specific structure that does leverage UUID based identifier. This will eliminate the burden of having to support UUID as the tag, and this enables projects that require UUID based identifiers for the broad range of HOB structures that need to be produced during the booting of the platform. Once we have a tag for a HOB list, this will enable various HOB producers that can add/extend the HOB list in TF-A code (or even pre-TF-A code), with a HOB consumer for that UUID/GUID on the other side (i.e. whatever the BL33 image is booting on that platform).
>>
>>
>>
>> Essentially, the idea is if someone would like to support HOB structures in a standard way using TF-A, they would wrap it up in a BL_AUX_PARAM/BLOB structure (whatever the group decides) and the way we identify the structure as a HOB list is with this new reserved tag.
>>
>>
>>
>> Hopefully that makes sense and less contentious. Look forward to discuss this further on the call.
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Sent: Friday, April 30, 2021 8:14 AM
>> To: François Ozog <francois.ozog(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi All,
>>
>>
>>
>> Please find invite for next TF-A Tech Forum session to continue our discussions on HOB implementation, feel free to forward it to others.
>>
>>
>>
>> The next TF-A Tech Forum is scheduled for Thu 6th May 2021 16:00 – 17:00 (BST).
>>
>>
>>
>> Agenda:
>>
>> Discussion Session: Static and Dynamic Information Handling in TF-A
>>
>> Lead by Manish Pandey and Madhukar Pappireddy
>>
>> · There is ongoing mailing lists discussion[1] related with adopting a mechanism to pass information through boot stages.
>>
>> The requirement is two-fold:
>>
>> 1. Passing static information(config files)
>>
>> 2. Passing dynamic information (Hob list)
>>
>> In the upcoming TF-A tech forum, we can start with a discussion on dynamic information passing and if time permits, we can cover static information passing. The purpose of the call is to have an open discussion and continue the discussion from the trusted-substrate call[2] done earlier. We would like to understand the various requirements and possible ways to implement it in TF-A in a generalized way so that it can work with other Firmware projects.
>>
>>
>>
>> The two specific item which we would like to discuss are:
>>
>> 1. HOB format: TF-A/u-boot both has an existing bloblist implementation, which uses tag values. Question, can this be enhanced to use hybrid values(Tag and UUID) both?
>>
>> 2. Standardization on Physical register use to pass base of HoB data structure.
>>
>> References:
>>
>> [1] https://lists.trustedfirmware.org/pipermail/tf-a/2021-April/001069.html
>>
>> [2] https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%
>>
>>
>>
>> Thanks
>>
>>
>>
>> Joanna
>>
>>
>>
>> You have been invited to the following event.
>>
>> TF-A Tech Forum
>>
>> When
>>
>> Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
>>
>> Calendar
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> Who
>>
>> •
>>
>> Bill Fletcher- creator
>>
>> •
>>
>> tf-a(a)lists.trustedfirmware.org
>>
>> more details »
>>
>>
>>
>> We run an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
>>
>>
>>
>> Feel free to forward this invite to colleagues. Invites are via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
>>
>>
>>
>> Trusted Firmware is inviting you to a scheduled Zoom meeting.
>>
>>
>>
>> Join Zoom Meeting
>>
>> https://zoom.us/j/9159704974
>>
>>
>>
>> Meeting ID: 915 970 4974
>>
>>
>>
>> One tap mobile
>>
>> +16465588656,,9159704974# US (New York)
>>
>> +16699009128,,9159704974# US (San Jose)
>>
>>
>>
>> Dial by your location
>>
>> +1 646 558 8656 US (New York)
>>
>> +1 669 900 9128 US (San Jose)
>>
>> 877 853 5247 US Toll-free
>>
>> 888 788 0099 US Toll-free
>>
>> Meeting ID: 915 970 4974
>>
>> Find your local number: https://zoom.us/u/ad27hc6t7h
>>
>>
>>
>> ________________________________
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: 08 April 2021 16:50
>> To: Manish Pandey2 <Manish.Pandey2(a)arm.com>
>> Cc: Simon Glass <sjg(a)chromium.org>; Julius Werner <jwerner(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Hi
>>
>>
>>
>> here is the meeting recording:
>>
>> https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn… Passcode: IPn+5q%z
>>
>>
>>
>> I am really sorry about the confusion related to the meeting time. I have now understood: the Collaborate portal uses a specific calendar which is tied to US/Chicago timezone while the actual Google Calendar is tied to Central Europe timezone. I am going to drop the Collaborate portal and use a shared Google calendar (it should be visible on the trusted-substrate.org page).
>>
>>
>>
>> I'll try to summarize what I learnt and highlight my view on what can be next steps in a future mail.
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>> On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
>>
>>
>>
>> To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
>>
>>
>>
>> The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
>>
>>
>>
>> One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
>>
>>
>>
>> Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
>>
>>
>>
>> Looking forward to having further discussions on zoom call today.
>>
>>
>>
>> Thanks
>>
>> Manish P
>>
>>
>>
>> ________________________________
>>
>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
>> Sent: 25 March 2021 02:43
>> To: Simon Glass <sjg(a)chromium.org>
>> Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
>>
>>
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>>
>>
>>
>> It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
>>
>>
>>
>> I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
>>
>>
>>
>> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi Harb,
>>
>>
>>
>> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com> wrote:
>>
>> Hello Folks,
>>
>> Appreciate the feedback and replies on this. Glad to see that there is interest in this topic.
>>
>>
>>
>> I try to address the comments/feedback from Francois and Simon below….
>>
>>
>>
>> @François Ozog – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
>>
>>
>>
>> Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
>>
>>
>>
>> The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
>>
>>
>>
>> Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
>>
>> “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
>> “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
>>
>>
>>
>> Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
>>
>>
>>
>> To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
>>
>>
>>
>> I understand the versatility of DT, but I see two major problems with DT:
>>
>> DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
>> DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
>>
>>
>>
>> I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
>>
>>
>>
>> Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
>>
>>
>>
>> Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
>>
>>
>>
>> @Simon Glass - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
>>
>>
>>
>> That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
>>
>>
>>
>> The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
>>
>>
>>
>> I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
>>
>>
>>
>> True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
>>
>>
>>
>> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
>> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
>> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
>>
>> (etc.)
>>
>>
>>
>> static struct guid_name {
>> efi_guid_t guid;
>> const char *name;
>> } guid_name[] = {
>> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
>> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
>> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
>> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
>> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
>> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
>> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
>>
>> (never figured out what those two are)
>>
>>
>> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
>> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
>> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
>> { {}, "zero-guid" },
>> {}
>> };
>>
>> static const char *guid_to_name(const efi_guid_t *guid)
>> {
>> struct guid_name *entry;
>>
>> for (entry = guid_name; entry->name; entry++) {
>> if (!guidcmp(guid, &entry->guid))
>> return entry->name;
>> }
>>
>> return NULL;
>> }
>>
>>
>>
>> Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
>>
>>
>>
>>
>>
>> We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
>>
>>
>>
>> Indeed. There is certainly value in both approaches.
>>
>>
>>
>> Regards,
>>
>> Simon
>>
>>
>>
>>
>>
>> Thanks,
>>
>> --Harb
>>
>>
>>
>> From: François Ozog <francois.ozog(a)linaro.org>
>> Sent: Tuesday, March 23, 2021 10:00 AM
>> To: François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
>> Cc: Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
>> Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
>>
>>
>>
>> +Ron Minnich +Paul Isaac's
>>
>>
>>
>> Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
>>
>>
>>
>> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>>
>> Hi,
>>
>>
>>
>> I propose we cover the topic at the next Trusted Substrate zoom call on April 8th 4pm CET.
>>
>>
>>
>> The agenda:
>>
>> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
>>
>> runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
>>
>>
>>
>> For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7, 5.5 Resource Descriptor HOB
>>
>> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
>>
>> This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
>>
>> HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
>>
>>
>>
>> There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
>>
>> I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
>>
>>
>>
>> Requirements (to be validated):
>>
>> - ACPI and DT hardware descriptions.
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>>
>> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
>>
>> - at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
>>
>> - support secure world device assignment
>>
>>
>>
>> Cheers
>>
>>
>>
>> FF
>>
>>
>>
>>
>>
>> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
>>
>> Hi,
>>
>> Can I suggest using bloblist for this instead? It is lightweight,
>> easier to parse, doesn't have GUIDs and is already used within U-Boot
>> for passing info between SPL/U-Boot, etc.
>>
>> Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
>> Header file describes the format:
>> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>>
>> Full set of unit tests:
>> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>>
>> Regards,
>> Simon
>>
>> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org> wrote:
>> >
>> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
>> >
>> > standardization is very much welcomed here and need to accommodate a very
>> > diverse set of situations.
>> > For example, TEE OS may need to pass memory reservations to BL33 or
>> > "capture" a device for the secure world.
>> >
>> > I have observed a number of architectures:
>> > 1) pass information from BLx to BLy in the form of a specific object
>> > 2) BLx called by BLy by a platform specific SMC to get information
>> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
>> > fixups
>> >
>> > I also imagined a standardized "broadcast" FF-A call so that any firmware
>> > element can either provide information or "do something".
>> >
>> > My understanding of your proposal is about standardizing on architecture 1)
>> > with the HOB format.
>> >
>> > The advantage of the HOB is simplicity but it may be difficult to implement
>> > schemes such as pruning a DT because device assignment in the secure world.
>> >
>> > In any case, it looks feasible to have TF-A and OP-TEE complement the list
>> > of HOBs to pass information downstream (the bootflow).
>> >
>> > It would be good to start with building the comprehensive list of
>> > information that need to be conveyed between firmware elements:
>> >
>> > information. | authoritative entity | reporting entity | information
>> > exchanged:
>> > dram | TFA | TFA |
>> > <format to be detailed, NUMA topology to build the SRAT table or DT
>> > equivalent?>
>> > PSCI | SCP | TFA? |
>> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
>> > secure SRAM | TFA. | TFA. |
>> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
>> > other? | |
>> > |
>> >
>> > Cheers
>> >
>> > FF
>> >
>> >
>> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
>> > tf-a(a)lists.trustedfirmware.org> wrote:
>> >
>> > > Hello Folks,
>> > >
>> > >
>> > >
>> > > I'm emailing to start an open discussion about the adoption of a concept
>> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
>> > > Framework Architecture (FFA). This is something that is a pretty major
>> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
>> > > designed to enable a broad range of highly configurable datacenter
>> > > platforms.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > What is a HOB (Background)?
>> > >
>> > > ---------------------------
>> > >
>> > > UEFI PI spec describes a particular definition for how HOB may be used for
>> > > transitioning between the PEI and DXE boot phases, which is a good
>> > > reference point for this discussion, but not necessarily the exact solution
>> > > appropriate for TF-A.
>> > >
>> > >
>> > >
>> > > A HOB is simply a dynamically generated data structure passed in between
>> > > two boot phases. This is information that was obtained through discovery
>> > > and needs to be passed forward to the next boot phase *once*, with no API
>> > > needed to call back (e.g. no call back into previous firmware phase is
>> > > needed to fetch this information at run-time - it is simply passed one time
>> > > during boot).
>> > >
>> > >
>> > >
>> > > There may be one or more HOBs passed in between boot phases. If there are
>> > > more than one HOB that needs to be passed, this can be in a form of a "HOB
>> > > table", which (for example) could be a UUID indexed array of pointers to
>> > > HOB structures, used to locate a HOB of interest (based on UUID). In such
>> > > cases, instead of passing a single HOB, the boot phases may rely on passing
>> > > the pointer to the HOB table.
>> > >
>> > >
>> > >
>> > > This has been extremely useful concept to employ on highly configurable
>> > > systems that must rely on flexible discovery mechanisms to initialize and
>> > > boot the system. This is especially helpful when you have multiple
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Why do we need HOBs in TF-A?:
>> > >
>> > > -----------------------------
>> > >
>> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
>> > > a way that is SoC specific *but* platform agnostic. This means that a
>> > > single ARM SoC that a SiP may deliver to customers may provide a single
>> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
>> > > range of platform designs and configurations in order to boot a platform
>> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
>> > > achieve this, the platform configuration must be *discovered* instead of
>> > > statically compiled as it is today in TF-A via device tree based
>> > > enumeration. The mechanisms of discovery may differ broadly depending on
>> > > the relevant industry standard, or in some cases may have rely on SiP
>> > > specific discovery flows.
>> > >
>> > >
>> > >
>> > > For example: On server systems that support a broad range DIMM memory
>> > > population/topologies, all the necessary information required to boot is
>> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
>> > > I2C bus. Leveraging the SPD bus, may platform variants could be supported
>> > > with a single TF-A binary. Not only is this information required to
>> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
>> > > phases will also need this SPD info to construct a system physical address
>> > > map and properly initialize the MMU based on the memory present, and where
>> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
>> > > need to generate standard firmware tables to the operating systems, such as
>> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
>> > > SRAT, even NFIT if NVDIMM's are present).
>> > >
>> > >
>> > >
>> > > In short, it all starts with a standardized or vendor specific discovery
>> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
>> > > information to the next boot stages (e.g. BL31/BL32/BL33).
>> > >
>> > >
>> > >
>> > > Today, every HOB may be a vendor specific structure, but in the future
>> > > there may be benefit of defining standard HOBs. This may be useful for
>> > > memory discovery, passing the system physical address map, enabling TPM
>> > > measured boot, and potentially many other common HOB use-cases.
>> > >
>> > >
>> > >
>> > > It would be extremely beneficial to the datacenter market segment if the
>> > > TF-A community would adopt this concept of information passing between all
>> > > boot phases as opposed to rely solely on device tree enumeration. This is
>> > > not intended to replace device tree, rather intended as an alternative way
>> > > to describe the info that must be discovered and dynamically generated.
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > Conclusion:
>> > >
>> > > -----------
>> > >
>> > > We are proposing that the TF-A community begin pursuing the adoption of
>> > > HOBs as a mechanism used for information exchange between each boot stage
>> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
>> > > want to explore standardizing some HOB structures for the BL33 phase (e.g.
>> > > UEFI HOB structures), but initially would like to agree on this being a
>> > > useful mechanism used to pass information between each boot stage.
>> > >
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > --Harb
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > > --
>> > > TF-A mailing list
>> > > TF-A(a)lists.trustedfirmware.org
>> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> > >
>> >
>> >
>> > --
>> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
>> > T: +33.67221.6485
>> > francois.ozog(a)linaro.org | Skype: ffozog
>> > _______________________________________________
>> > boot-architecture mailing list
>> > boot-architecture(a)lists.linaro.org
>> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>>
>>
>>
>> --
>>
>> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
>>
>> T: +33.67221.6485
>> francois.ozog(a)linaro.org | Skype: ffozog
>>
>>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
If I understand the cold boot attack correctly for the normal world, it is that we boot a NWd OS once, make it decrypt all its secrets into DRAM, pull the power and quickly boot to another OS and read contents of DRAM before the data decays, to extract secrets of the old OS using the new OS. While this can apply to secure world, It might be a safe assumption that we cannot boot arbitrary, unsigned TZ code and trusted OS's on an ARM system in the last few years due to use of CoT, Rollback protection etc.
As a general rule of thumb, early boot code should probably be scrubbing secure DRAM anyway, I think, to prevent this attack, in which case the way to do the cold boot attack would be through a run time attack on TZ code.
Thanks
Raghu
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Okash Khawaja via TF-A
Sent: Wednesday, May 5, 2021 9:10 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] MEM_PROTECT for secure world?
Hi,
As a PSCI call, MEM_PROTECT which is used to protect against cold reboot attack, can't be called from TZ-secure. In a situation where at run time, HLOS in NS-EL1 transfers some buffer that it owns, to a secure partition then secure partition can't call MEM_PROTECT because psci_smc_handler will return SMC_UNK if the caller is secure.
Should MEM_PROTECT be available to TZ-secure as well?
Thanks,
Okash
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Adding tf-a list again.
-----Original Message-----
From: raghu.ncstate(a)icloud.com <raghu.ncstate(a)icloud.com>
Sent: Thursday, May 13, 2021 9:33 AM
To: 'Heiko Thiery' <heiko.thiery(a)gmail.com>; 'tf-a-bounces(a)lists.trustedfirmware.org' <tf-a-bounces(a)lists.trustedfirmware.org>
Subject: RE: [TF-A] Stack Protector for platforms not implementing plat_get_stack_protector_canary
Right. The point I was trying to make is the same as the comment in the C file says "this is better than nothing but not necessarily really secure". I'm just saying SSP without truly random stack canary in an open source project is as good as not having SSP 😊
>From an TF-A point of view, I think we want to encourage folks to include TRNG's on their platform and we should not provide an insecure default implementation, since people may assume security properties about it if they don’t look closely enough.
Thanks
Raghu
-----Original Message-----
From: Heiko Thiery <heiko.thiery(a)gmail.com>
Sent: Thursday, May 13, 2021 8:57 AM
To: raghu.ncstate(a)icloud.com; tf-a-bounces(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Stack Protector for platforms not implementing plat_get_stack_protector_canary
Hi,
Am Do., 13. Mai 2021 um 17:13 Uhr schrieb <raghu.ncstate(a)icloud.com>:
>
> Without a RNG, implementing a generic function as you have mentioned below would mean returning a constant value or random numbers that are not cryptographically secure for the stack canary. Neither of those options will really provide any security benefit. In absence of a TRNG or secret seed that can be used to generate secure random numbers, I think turning off SSP is not that much worse than returning bad values.
But as you can read in the comments of some implementations, it is better to return a pseudo value than none at all. Or am I wrong there?
And assuming that this is true, it would be good to have an implementation for all those who don't use TRNG like the ones at
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/rockc….
>
> A quick google search tells me that imx8m may have a random number generator so the platform code may need to hook up tf-a platform port to the random number.
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Heiko
> Thiery via TF-A
> Sent: Thursday, May 13, 2021 12:34 AM
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] Stack Protector for platforms not implementing
> plat_get_stack_protector_canary
>
> Hi all,
>
> I recently encountered a build issue with the imx8m platform.
> Buildroot will set the SSP (Stack Smashing Protection) option to on by
> default in the next release. This option also turns on the
> ENABLE_STACK_PROTECTOR in the ATF. But since the
> plat_get_stack_protector_canary() function is not implemented for the
> imx8m for example, the build fails for this platform. My question now
> is: could you implement a generic function like it is implemented for some platforms that don't have a real RNG? Or is there a concern here?
>
> I must admit that I have no experience with ATF other than building and deploying it.
>
> Thanks
> --
> Heiko
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
Thanks
--
Heiko
Hi Raghu,
That’s should have been corrected as there was a fault on trustedfirmware.org servers which was fixed overnight as I was also missing notifications but they have started to come through now.
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: "raghu.ncstate(a)icloud.com" <raghu.ncstate(a)icloud.com>
Date: Thursday, 13 May 2021 at 15:47
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Lost gerrit email notifications
Hi All,
I seem to have lost email notification of comments on gerrit reviews. I’ve checked my gerrit settings and reset the settings to enable notifications but I cant seem to get notifications from gerrit. Is this something others are seeing as well?
Thanks
Raghu
Hi All,
I seem to have lost email notification of comments on gerrit reviews. I've
checked my gerrit settings and reset the settings to enable notifications
but I cant seem to get notifications from gerrit. Is this something others
are seeing as well?
Thanks
Raghu
Hi all,
I recently encountered a build issue with the imx8m platform.
Buildroot will set the SSP (Stack Smashing Protection) option to on by
default in the next release. This option also turns on the
ENABLE_STACK_PROTECTOR in the ATF. But since the
plat_get_stack_protector_canary() function is not implemented for the
imx8m for example, the build fails for this platform. My question now
is: could you implement a generic function like it is implemented for
some platforms that don't have a real RNG? Or is there a concern here?
I must admit that I have no experience with ATF other than building
and deploying it.
Thanks
--
Heiko
Hi
here is the meeting recording:
https://linaro-org.zoom.us/rec/share/zjfHeMIumkJhirLCVQYTHR6ftaqyWvF_0klgQn…
Passcode: IPn+5q%z
I am really sorry about the confusion related to the meeting time. I have
now understood: the Collaborate portal uses a specific calendar which is
tied to US/Chicago timezone while the actual Google Calendar is tied to
Central Europe timezone. I am going to drop the Collaborate portal and use
a shared Google calendar (it should be visible on the trusted-substrate.org
page).
I'll try to summarize what I learnt and highlight my view on what can be
next steps in a future mail.
Cheers
FF
On Thu, 8 Apr 2021 at 13:56, Manish Pandey2 via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> Hi,
>
> From TF-A project point of view, we prefer to use existing mechanism to
> pass parameters across boot stages using linked list of tagged elements (as
> suggested by Julius). It has support for both generic and SiP-specific
> tags. Having said that, it does not stop partners to introduce new
> mechanisms suitable for their usecase in platform port initially and later
> move to generic code if its suitable for other platforms.
>
> To start with, Ampere can introduce a platform specific implementation of
> memory tag(speed/NUMA topology etc) which can be evaluated and discussed
> for generalization in future. The tag will be populated in BL2 stage and
> can be forwarded to further stages(and to BL33) by passing the head of list
> pointer in one of the registers. Initially any register can be used but
> going forward a standardization will be needed.
>
> The U-boot bloblist mentioned by Simon is conceptually similar to what
> TF-A is using, if there is consensus of using bloblist/taglist then TF-A
> tag list may be enhanced to take best of both the implementations.
>
> One of the potential problems of having structure used in different
> projects is maintainability, this can be avoided by having a single copy of
> these structures in TF-A (kept inside "include/export" which intended to be
> used by other projects.)
>
> Regarding usage of either UUID or tag, I echo the sentiments of Simon and
> Julius to keep it simple and use tag values.
>
> Looking forward to having further discussions on zoom call today.
>
> Thanks
> Manish P
>
> ------------------------------
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius
> Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
> *Sent:* 25 March 2021 02:43
> *To:* Simon Glass <sjg(a)chromium.org>
> *Cc:* Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot
> Architecture Mailman List <boot-architecture(a)lists.linaro.org>;
> tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot
> Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>;
> Ron Minnich <rminnich(a)google.com>
> *Subject:* Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for
> information passing between boot stages
>
> Just want to point out that TF-A currently already supports a (very
> simple) mechanism like this:
>
>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>
> https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
>
> It's just a linked list of tagged elements. The tag space is split into
> TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare
> if more areas need to be defined -- a 64-bit tag can fit a lot). This is
> currently being used by some platforms that run coreboot in place of
> BL1/BL2, to pass information from coreboot (BL2) to BL31.
>
> I would echo Simon's sentiment of keeping this as simple as possible and
> avoiding complicated and bloated data structures with UUIDs. You usually
> want to parse something like this as early as possible in the passed-to
> firmware stage, particularly if the structure encodes information about the
> debug console (like it does for the platforms I mentioned above). For
> example, in BL31 this basically means doing it right after moving from
> assembly to C in bl31_early_platform_setup2() to get the console up before
> running anything else. At that point in the BL31 initialization, the MMU
> and caches are disabled, so data accesses are pretty expensive and you
> don't want to spend a lot of parsing effort or calculate complicated
> checksums or the like. You just want something extremely simple where you
> ideally have to touch every data word only once.
>
> On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Harb,
>
> On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com> wrote:
>
> Hello Folks,
>
> Appreciate the feedback and replies on this. Glad to see that there is
> interest in this topic. 😊
>
>
>
> I try to address the comments/feedback from Francois and Simon below….
>
>
>
> @François Ozog <francois.ozog(a)linaro.org> – happy to discuss this on a
> zoom call. I will make that time slot work, and will be available to
> attend April 8, 4pm CT.
>
>
>
> Note that I’m using the term “HOB” here more generically, as there are
> typically vendor specific structures beyond the resource descriptor HOB,
> which provides only a small subset of the information that needs to be
> passed between the boot phases.
>
>
>
> The whole point here is to provide mechanism to develop firmware that we
> can build ARM Server SoC’s that support **any** BL33 payload (e.g. EDK2,
> AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some
> point). In other-words, we are trying to come up with a TF-A that would
> be completely agnostic to the implementation of BL33 (i.e. BL33 is built
> completely independently by a separate entity – e.g. an ODM/OEM).
>
>
>
> Keep in mind, in the server/datacenter market segment we are not building
> vertically integrated systems with a single entity compiling
> firmware/software stacks like most folks in TF-A have become use to. There
> are two categories of higher level firmware code blobs in the
> server/datacenter model:
>
> 1. “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2,
> BL31, and **possibly** one or more BL32 instances
> 2. “Platform” or “board” firmware – in TF-A this may map to BL33 and *
> *possibly** one or more BL32 instances.
>
>
>
> Even the platform firmware stack could be further fragmented by having
> multiple entities involved in delivering the entire firmware stack: IBVs,
> ODMs, OEMs, CSPs, and possibly even device vendor code.
>
>
>
> To support a broad range of platform designs with a broad range of memory
> devices, we need a crisp and clear contract between the SoC firmware that
> initializes memory (e.g. BL2) and how that platform boot firmware (e.g.
> BL33) gathers information about what memory that was initialized, at what
> speeds, NUMA topology, and many other relevant information that needs to be
> known and comprehended by the platform firmware and eventually by the
> platform software.
>
>
>
> I understand the versatility of DT, but I see two major problems with DT:
>
> - DT requires more complicated parsing to get properties, and even
> more complex to dynamically set properties – this HOB structures may need
> to be generated in boot phases where DDR is not available, and therefore we
> will be extremely memory constrained.
> - DT is probably overkill for this purpose – We really just want a
> list of pointers to simple C structures that code cast (e.g. JEDEC SPD data
> blob)
>
>
>
> I think that we should not mix the efforts around DT/ACPI specs with what
> we are doing here, because those specs and concepts were developed for a
> completely different purpose (i.e. abstractions needed for OS / RTOS
> software, and not necessarily suitable for firmware-to-firmware hand-offs).
>
>
>
> Frankly, I would personally push back pretty hard on defining SMC’s for
> something that should be one way information passing. Every SMC we add is
> another attack vector to the secure world and an increased burden on the
> folks that have to do security auditing and threat analysis. I see no
> benefit in exposing these boot/HOB/BOB structures at run-time via SMC
> calls.
>
>
>
> Please do let me know if you disagree and why. Look forward to discussing
> on this thread or on the call.
>
>
>
> @Simon Glass <sjg(a)chromium.org> - Thanks for the pointer to bloblist.
> I briefly reviewed and it seems like a good baseline for what we may be
> looking for.
>
>
>
> That being said, I would say that there is some benefit in having some
> kind of unique identifiers (e.g. UUID or some unique signature) so that we
> can tie standardized data structures (based on some future TBD specs) to a
> particular ID. For example, if the TPM driver in BL33 is looking for the
> TPM structure in the HOB/BOB list, and may not care about the other data
> blobs. The driver needs a way to identify and locate the blob it cares
> about.
>
>
> The tag is intended to serve that purpose, although perhaps it should
> switch from an auto-allocating enum to one with explicit values for each
> entry and a range for 'local' use.
>
>
>
> I guess we can achieve this with the tag, but the problem with tag when
> you have eco-system with a lot of parties doing parallel development, you
> can end up with tag collisions and folks fighting about who has rights to
> what tag values. We would need some official process for folks to register
> tags for whatever new structures we define, or maybe some tag range for
> vendor specific structures. This comes with a lot of pain and
> bureaucracy. On the other hand, UUID has been a proven way to make it easy
> to just define your own blobs with **either** standard or vendor specific
> structures without worry of ID collisions between vendors.
>
>
> True. I think the pain is overstated, though. In this case I think we
> actually want something that can be shared between projects and orgs, so
> some amount of coordination could be considered a benefit. It could just be
> a github pull request. I find the UUID unfriendly and not just to code size
> and eyesight! Trying to discover what GUIDs mean or are valid is quite
> tricky. E.g. see this code:
>
> #define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
> EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
> 0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
> (etc.)
>
> static struct guid_name {
> efi_guid_t guid;
> const char *name;
> } guid_name[] = {
> { FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
> { FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
> { FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
> { FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
> { FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
> { FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
> { FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
> (never figured out what those two are)
>
> { FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
> { FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
> { FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
> { {}, "zero-guid" },
> {}
> };
>
> static const char *guid_to_name(const efi_guid_t *guid)
> {
> struct guid_name *entry;
>
> for (entry = guid_name; entry->name; entry++) {
> if (!guidcmp(guid, &entry->guid))
> return entry->name;
> }
>
> return NULL;
> }
>
> Believe it or not it took a fair bit of effort to find just that small
> list, with nearly every one in a separate doc, from memory.
>
>
>
> We can probably debate whether there is any value in GUID/UUID or not
> during the call… but again, boblist seems like a reasonable starting point
> as an alternative to HOB.
>
>
> Indeed. There is certainly value in both approaches.
>
> Regards,
> Simon
>
>
>
>
> Thanks,
>
> --Harb
>
>
>
> *From:* François Ozog <francois.ozog(a)linaro.org>
> *Sent:* Tuesday, March 23, 2021 10:00 AM
> *To:* François Ozog <francois.ozog(a)linaro.org>; Ron Minnich <
> rminnich(a)google.com>; Paul Isaac's <paul.isaacs(a)linaro.org>
> *Cc:* Simon Glass <sjg(a)chromium.org>; Harb Abdulhamid OS <
> abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org
> *Subject:* Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for
> information passing between boot stages
>
>
>
> +Ron Minnich <rminnich(a)google.com> +Paul Isaac's <paul.isaacs(a)linaro.org>
>
>
>
> Adding Ron and Paul because I think this interface should be also
> benefiting LinuxBoot efforts.
>
>
>
> On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <
> tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi,
>
>
>
> I propose we cover the topic at the next Trusted Substrate
> <https://collaborate.linaro.org/display/TS/Trusted+Substrate+Home> zoom
> call <https://linaro-org.zoom.us/j/94563644892> on April 8th 4pm CET.
>
>
>
> The agenda:
>
> ABI between non-secure firmware and the rest of firmware (EL3, S-EL1,
> S-EL2, SCP) to adapt hardware description to some runtime conditions.
>
> runtime conditions here relates to DRAM size and topology detection,
> secure DRAM memory carvings, PSCI and SCMI interface publishing.
>
>
>
> For additional background on existing metadata: UEFI Platform
> Initialization Specification Version 1.7
> <https://uefi.org/sites/default/files/resources/PI_Spec_1_7_final_Jan_2019.p…>
> , 5.5 Resource Descriptor HOB
>
> Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
>
> This HOB lacks memory NUMA attachment or something that could be related
> to fill SRAT table for ACPI or relevant DT proximity domains.
>
> HOB is not consistent accros platforms: some platforms (Arm) lists memory
> from the booting NUMA node, other platforms (x86) lists all memory from all
> NUMA nodes. (At least this is the case on the two platforms I tested).
>
>
>
> There are two proposals to use memory structures from SPL/BLx up to the
> handover function (as defined in the Device Tree technical report
> <https://docs.google.com/document/d/1CLkhLRaz_zcCq44DLGmPZQFPbYHOC6nzPowaL0X…>)
> which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or
> EDK2.
>
> I would propose we also discuss possibility of FF-A interface to actually
> query information or request actions to be done (this is a model actually
> used in some SoCs with proprietary SMC calls).
>
>
>
> Requirements (to be validated):
>
> - ACPI and DT hardware descriptions.
>
> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
>
> - agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2,
> TF-A/LinuxBoot)
>
> - at least allows complete DRAM description and "persistent" usage
> (reserved areas for secure world or other usages)
>
> - support secure world device assignment
>
>
>
> Cheers
>
>
>
> FF
>
>
>
>
>
> On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org> wrote:
>
> Hi,
>
> Can I suggest using bloblist for this instead? It is lightweight,
> easier to parse, doesn't have GUIDs and is already used within U-Boot
> for passing info between SPL/U-Boot, etc.
>
> Docs here:
> https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
> Header file describes the format:
> https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
>
> Full set of unit tests:
> https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
>
> Regards,
> Simon
>
> On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org>
> wrote:
> >
> > +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>
> >
> > standardization is very much welcomed here and need to accommodate a very
> > diverse set of situations.
> > For example, TEE OS may need to pass memory reservations to BL33 or
> > "capture" a device for the secure world.
> >
> > I have observed a number of architectures:
> > 1) pass information from BLx to BLy in the form of a specific object
> > 2) BLx called by BLy by a platform specific SMC to get information
> > 3) BLx called by BLy by a platform specific SMC to perform Device Tree
> > fixups
> >
> > I also imagined a standardized "broadcast" FF-A call so that any firmware
> > element can either provide information or "do something".
> >
> > My understanding of your proposal is about standardizing on architecture
> 1)
> > with the HOB format.
> >
> > The advantage of the HOB is simplicity but it may be difficult to
> implement
> > schemes such as pruning a DT because device assignment in the secure
> world.
> >
> > In any case, it looks feasible to have TF-A and OP-TEE complement the
> list
> > of HOBs to pass information downstream (the bootflow).
> >
> > It would be good to start with building the comprehensive list of
> > information that need to be conveyed between firmware elements:
> >
> > information. | authoritative entity | reporting entity | information
> > exchanged:
> > dram | TFA | TFA |
> > <format to be detailed, NUMA topology to build the SRAT table or DT
> > equivalent?>
> > PSCI | SCP | TFA? |
> > SCMI | SCP or TEE-OS | TFA? TEE-OS?|
> > secure SRAM | TFA. | TFA. |
> > secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
> > other? | |
> > |
> >
> > Cheers
> >
> > FF
> >
> >
> > On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
> > tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > > Hello Folks,
> > >
> > >
> > >
> > > I'm emailing to start an open discussion about the adoption of a
> concept
> > > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
> > > Framework Architecture (FFA). This is something that is a pretty major
> > > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
> > > designed to enable a broad range of highly configurable datacenter
> > > platforms.
> > >
> > >
> > >
> > >
> > >
> > > What is a HOB (Background)?
> > >
> > > ---------------------------
> > >
> > > UEFI PI spec describes a particular definition for how HOB may be used
> for
> > > transitioning between the PEI and DXE boot phases, which is a good
> > > reference point for this discussion, but not necessarily the exact
> solution
> > > appropriate for TF-A.
> > >
> > >
> > >
> > > A HOB is simply a dynamically generated data structure passed in
> between
> > > two boot phases. This is information that was obtained through
> discovery
> > > and needs to be passed forward to the next boot phase *once*, with no
> API
> > > needed to call back (e.g. no call back into previous firmware phase is
> > > needed to fetch this information at run-time - it is simply passed one
> time
> > > during boot).
> > >
> > >
> > >
> > > There may be one or more HOBs passed in between boot phases. If there
> are
> > > more than one HOB that needs to be passed, this can be in a form of a
> "HOB
> > > table", which (for example) could be a UUID indexed array of pointers
> to
> > > HOB structures, used to locate a HOB of interest (based on UUID). In
> such
> > > cases, instead of passing a single HOB, the boot phases may rely on
> passing
> > > the pointer to the HOB table.
> > >
> > >
> > >
> > > This has been extremely useful concept to employ on highly configurable
> > > systems that must rely on flexible discovery mechanisms to initialize
> and
> > > boot the system. This is especially helpful when you have multiple
> > >
> > >
> > >
> > >
> > >
> > > Why do we need HOBs in TF-A?:
> > >
> > > -----------------------------
> > >
> > > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC
> in
> > > a way that is SoC specific *but* platform agnostic. This means that a
> > > single ARM SoC that a SiP may deliver to customers may provide a single
> > > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
> > > range of platform designs and configurations in order to boot a
> platform
> > > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
> > > achieve this, the platform configuration must be *discovered* instead
> of
> > > statically compiled as it is today in TF-A via device tree based
> > > enumeration. The mechanisms of discovery may differ broadly depending
> on
> > > the relevant industry standard, or in some cases may have rely on SiP
> > > specific discovery flows.
> > >
> > >
> > >
> > > For example: On server systems that support a broad range DIMM memory
> > > population/topologies, all the necessary information required to boot
> is
> > > fully discovered via standard JEDEC Serial Presence Detect (SPD) over
> an
> > > I2C bus. Leveraging the SPD bus, may platform variants could be
> supported
> > > with a single TF-A binary. Not only is this information required to
> > > initialize memory in early boot phases (e.g. BL2), the subsequent boot
> > > phases will also need this SPD info to construct a system physical
> address
> > > map and properly initialize the MMU based on the memory present, and
> where
> > > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI)
> may
> > > need to generate standard firmware tables to the operating systems,
> such as
> > > SMBIOS tables describing DIMM topology and various ACPI tables (e.g.
> SLIT,
> > > SRAT, even NFIT if NVDIMM's are present).
> > >
> > >
> > >
> > > In short, it all starts with a standardized or vendor specific
> discovery
> > > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
> > > information to the next boot stages (e.g. BL31/BL32/BL33).
> > >
> > >
> > >
> > > Today, every HOB may be a vendor specific structure, but in the future
> > > there may be benefit of defining standard HOBs. This may be useful for
> > > memory discovery, passing the system physical address map, enabling TPM
> > > measured boot, and potentially many other common HOB use-cases.
> > >
> > >
> > >
> > > It would be extremely beneficial to the datacenter market segment if
> the
> > > TF-A community would adopt this concept of information passing between
> all
> > > boot phases as opposed to rely solely on device tree enumeration.
> This is
> > > not intended to replace device tree, rather intended as an alternative
> way
> > > to describe the info that must be discovered and dynamically generated.
> > >
> > >
> > >
> > >
> > >
> > > Conclusion:
> > >
> > > -----------
> > >
> > > We are proposing that the TF-A community begin pursuing the adoption of
> > > HOBs as a mechanism used for information exchange between each boot
> stage
> > > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
> > > want to explore standardizing some HOB structures for the BL33 phase
> (e.g.
> > > UEFI HOB structures), but initially would like to agree on this being a
> > > useful mechanism used to pass information between each boot stage.
> > >
> > >
> > >
> > > Thanks,
> > >
> > > --Harb
> > >
> > >
> > >
> > >
> > >
> > >
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >
> >
> >
> > --
> > François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
> > T: +33.67221.6485
> > francois.ozog(a)linaro.org | Skype: ffozog
> > _______________________________________________
> > boot-architecture mailing list
> > boot-architecture(a)lists.linaro.org
> > https://lists.linaro.org/mailman/listinfo/boot-architecture
>
>
>
>
> --
>
> *François-Frédéric Ozog* | *Director Linaro Edge & Fog Computing Group*
>
> T: +33.67221.6485
> francois.ozog(a)linaro.org | Skype: ffozog
>
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
>
>
>
> --
>
> *François-Frédéric Ozog* | *Director Linaro Edge & Fog Computing Group*
>
> T: +33.67221.6485
> francois.ozog(a)linaro.org | Skype: ffozog
>
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi Rockchip platform maintainers,
There's a build issue spotted with GCC11 on rk3399 platform reported here using tip of master: https://developer.trustedfirmware.org/T925
The issue is not breaking the build with earlier gcc versions, but we think the error is legitimate and caused by a mistake in the platform code. Details in the ticket.
Any chance for you to have a look?
Thanks, Olivier.
Hi,
As a PSCI call, MEM_PROTECT which is used to protect against cold
reboot attack, can't be called from TZ-secure. In a situation where at
run time, HLOS in NS-EL1 transfers some buffer that it owns, to a
secure partition then secure partition can't call MEM_PROTECT because
psci_smc_handler will return SMC_UNK if the caller is secure.
Should MEM_PROTECT be available to TZ-secure as well?
Thanks,
Okash
Le mar. 27 avr. 2021 à 11:04, Loh, Tien Hock via TF-A <
tf-a(a)lists.trustedfirmware.org> a écrit :
> Achin,
>
> Yes that’s what I have suspected in the first place, but no harm asking :)
>
>
>
> Tien Fong,
>
> As per discussed, we could probably expose the a compile time option in
> BL31 that expose a command that read/write to the secure domain.
>
> That case, u-boot shell will be able to access secure domain and not need
> to run in EL3.
>
Would you allow an OS to access underlying hypervisor ?
In essence this is what you are asking:
there are architectural services such as kicking off a new cpu that are
supposed to be routed to the right service handler (PSCI) or secure
firmware updates with anti-bricking support....
Could you be more specific on what you want to do and why ?
That may help us advise on achieving your goals while still being
architecturally correct.
>
>
> Thanks
>
>
>
> *From:* Chee, Tien Fong <tien.fong.chee(a)intel.com>
> *Sent:* Tuesday, April 27, 2021 5:01 PM
> *To:* Achin Gupta <Achin.Gupta(a)arm.com>; tf-a(a)lists.trustedfirmware.org;
> Loh, Tien Hock <tien.hock.loh(a)intel.com>
> *Cc:* See, Chin Liang <chin.liang.see(a)intel.com>; Hea, Kok Kiang <
> kok.kiang.hea(a)intel.com>
> *Subject:* RE: Run BL33 (u-boot) in EL3
>
>
>
> Hi Achin,
>
>
>
> Thanks for the feedback.
>
>
>
> This is use case when user doing development, testing and bring up the
> board, they can use this option to run their script on U-Boot shell to
> access these secure region. Once they have finished the development, and
> testing, then user can switch U-Boot into EL2. This flexibility would
> definitely giving some degree of convenience for development and testing.
>
>
>
> Thanks.
>
>
>
> *From:* Achin Gupta <Achin.Gupta(a)arm.com>
> *Sent:* Tuesday, 27 April, 2021 4:38 PM
> *To:* tf-a(a)lists.trustedfirmware.org; Loh, Tien Hock <
> tien.hock.loh(a)intel.com>
> *Cc:* Chee, Tien Fong <tien.fong.chee(a)intel.com>; See, Chin Liang <
> chin.liang.see(a)intel.com>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com>
> *Subject:* Re: Run BL33 (u-boot) in EL3
>
>
>
> Hi Tien Hock,
>
>
>
> The maintainers will have more thoughts on this but my $0.02 fwiw.
>
>
>
> I cannot see why the Trusted Firmware project should carry any option that
> enables use of EL3 by users who do not care about security. EL3 is not
> meant to run u-boot with a shell that can be used to fiddle with secure
> memory. This flies against the basic security principles that the project
> is built upon.
>
>
>
> cheers,
> Achin
>
>
> ------------------------------
>
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Loh,
> Tien Hock via TF-A <tf-a(a)lists.trustedfirmware.org>
> *Sent:* 27 April 2021 09:02
> *To:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> *Cc:* Chee, Tien Fong <tien.fong.chee(a)intel.com>; See, Chin Liang <
> chin.liang.see(a)intel.com>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com>
> *Subject:* [TF-A] Run BL33 (u-boot) in EL3
>
>
>
> Hi,
>
>
>
> I’m maintaining TF-A for Intel SoCFPGA platform.
>
> Would it be possible if we should have the option to run BL33 (u-boot in
> our case) in EL3?
>
>
>
> The Intel SoCFPGA platform u-boot used to handle all SMC calls:
>
> SPL u-boot (EL3) -> u-boot (EL3)
>
> And we have since move to use TF-A’s BL31, thus boot became
> SPL u-boot (EL3) -> TF-A BL31 (EL3) -> u-boot (EL2)
>
>
>
> Main reason is that some users would like to keep u-boot at EL3 as they do
> not care about security, and some users wanted to run some debugging
> read/write to secure region in u-boot shell.
>
>
>
> Thanks
>
> Tien Hock
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi Tien Hock,
Did you explored EL3_PAYLOAD_BASE build option. This option enables booting an EL3 payload, if it suits you then u-boot as EL3 payload.
thanks
Manish
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 27 April 2021 20:16
To: Loh, Tien Hock <tien.hock.loh(a)intel.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; See, Chin Liang <chin.liang.see(a)intel.com>; Chee, Tien Fong <tien.fong.chee(a)intel.com>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com>
Subject: Re: [TF-A] Run BL33 (u-boot) in EL3
Le mar. 27 avr. 2021 à 11:04, Loh, Tien Hock via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> a écrit :
Achin,
Yes that’s what I have suspected in the first place, but no harm asking :)
Tien Fong,
As per discussed, we could probably expose the a compile time option in BL31 that expose a command that read/write to the secure domain.
That case, u-boot shell will be able to access secure domain and not need to run in EL3.
Would you allow an OS to access underlying hypervisor ?
In essence this is what you are asking:
there are architectural services such as kicking off a new cpu that are supposed to be routed to the right service handler (PSCI) or secure firmware updates with anti-bricking support....
Could you be more specific on what you want to do and why ?
That may help us advise on achieving your goals while still being architecturally correct.
Thanks
From: Chee, Tien Fong <tien.fong.chee(a)intel.com<mailto:tien.fong.chee@intel.com>>
Sent: Tuesday, April 27, 2021 5:01 PM
To: Achin Gupta <Achin.Gupta(a)arm.com<mailto:Achin.Gupta@arm.com>>; tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>; Loh, Tien Hock <tien.hock.loh(a)intel.com<mailto:tien.hock.loh@intel.com>>
Cc: See, Chin Liang <chin.liang.see(a)intel.com<mailto:chin.liang.see@intel.com>>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com<mailto:kok.kiang.hea@intel.com>>
Subject: RE: Run BL33 (u-boot) in EL3
Hi Achin,
Thanks for the feedback.
This is use case when user doing development, testing and bring up the board, they can use this option to run their script on U-Boot shell to access these secure region. Once they have finished the development, and testing, then user can switch U-Boot into EL2. This flexibility would definitely giving some degree of convenience for development and testing.
Thanks.
From: Achin Gupta <Achin.Gupta(a)arm.com<mailto:Achin.Gupta@arm.com>>
Sent: Tuesday, 27 April, 2021 4:38 PM
To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>; Loh, Tien Hock <tien.hock.loh(a)intel.com<mailto:tien.hock.loh@intel.com>>
Cc: Chee, Tien Fong <tien.fong.chee(a)intel.com<mailto:tien.fong.chee@intel.com>>; See, Chin Liang <chin.liang.see(a)intel.com<mailto:chin.liang.see@intel.com>>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com<mailto:kok.kiang.hea@intel.com>>
Subject: Re: Run BL33 (u-boot) in EL3
Hi Tien Hock,
The maintainers will have more thoughts on this but my $0.02 fwiw.
I cannot see why the Trusted Firmware project should carry any option that enables use of EL3 by users who do not care about security. EL3 is not meant to run u-boot with a shell that can be used to fiddle with secure memory. This flies against the basic security principles that the project is built upon.
cheers,
Achin
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>> on behalf of Loh, Tien Hock via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Sent: 27 April 2021 09:02
To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Cc: Chee, Tien Fong <tien.fong.chee(a)intel.com<mailto:tien.fong.chee@intel.com>>; See, Chin Liang <chin.liang.see(a)intel.com<mailto:chin.liang.see@intel.com>>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com<mailto:kok.kiang.hea@intel.com>>
Subject: [TF-A] Run BL33 (u-boot) in EL3
Hi,
I’m maintaining TF-A for Intel SoCFPGA platform.
Would it be possible if we should have the option to run BL33 (u-boot in our case) in EL3?
The Intel SoCFPGA platform u-boot used to handle all SMC calls:
SPL u-boot (EL3) -> u-boot (EL3)
And we have since move to use TF-A’s BL31, thus boot became
SPL u-boot (EL3) -> TF-A BL31 (EL3) -> u-boot (EL2)
Main reason is that some users would like to keep u-boot at EL3 as they do not care about security, and some users wanted to run some debugging read/write to secure region in u-boot shell.
Thanks
Tien Hock
--
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TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
[https://drive.google.com/a/linaro.org/uc?id=0BxTAygkus3RgQVhuNHMwUi1mYWc&ex…]
François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
T: +33.67221.6485
francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org> | Skype: ffozog
Hi Tien Hock,
The maintainers will have more thoughts on this but my $0.02 fwiw.
I cannot see why the Trusted Firmware project should carry any option that enables use of EL3 by users who do not care about security. EL3 is not meant to run u-boot with a shell that can be used to fiddle with secure memory. This flies against the basic security principles that the project is built upon.
cheers,
Achin
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Loh, Tien Hock via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 27 April 2021 09:02
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Cc: Chee, Tien Fong <tien.fong.chee(a)intel.com>; See, Chin Liang <chin.liang.see(a)intel.com>; Hea, Kok Kiang <kok.kiang.hea(a)intel.com>
Subject: [TF-A] Run BL33 (u-boot) in EL3
Hi,
I’m maintaining TF-A for Intel SoCFPGA platform.
Would it be possible if we should have the option to run BL33 (u-boot in our case) in EL3?
The Intel SoCFPGA platform u-boot used to handle all SMC calls:
SPL u-boot (EL3) -> u-boot (EL3)
And we have since move to use TF-A’s BL31, thus boot became
SPL u-boot (EL3) -> TF-A BL31 (EL3) -> u-boot (EL2)
Main reason is that some users would like to keep u-boot at EL3 as they do not care about security, and some users wanted to run some debugging read/write to secure region in u-boot shell.
Thanks
Tien Hock
Hi,
I am trying to enable SPM on iMX8MP platform, which is cortex-A53. The
BL2 is already enabled and the dts file is needed. But I am not sure
how to write below dts information when I referencing
fvp_spmc_manifest.dts. Could you help to give some suggestion or where
should I find the anwsers?
1. Is fvp_spmc_manifest.dts enough to enable SPM? I see there are dts
files, such as fvp_fw_config.dts. What's necessary dts nodes to enable
SPM?
2. Does vcpu_count means CPU number?
3. I see load_address of attribute is optee-os load address. But I do
not know how should I decide the load addresses of hypervisors. Is
this address decided by virtual machine, or it is decided in runtime?
I cannot find the 0x7100000 in trusted-services project.
4. I am confused on "Secure Partitions are bundled as independent
package files" in below link. Does this bundle package means fip
image, or into another file by jason file? Could you help point to the
files and image generation command?
https://github.com/ARM-software/arm-trusted-firmware/blob/master/docs/compo…
Regards,
Jun
Hi,
I'm maintaining TF-A for Intel SoCFPGA platform.
Would it be possible if we should have the option to run BL33 (u-boot in our case) in EL3?
The Intel SoCFPGA platform u-boot used to handle all SMC calls:
SPL u-boot (EL3) -> u-boot (EL3)
And we have since move to use TF-A's BL31, thus boot became
SPL u-boot (EL3) -> TF-A BL31 (EL3) -> u-boot (EL2)
Main reason is that some users would like to keep u-boot at EL3 as they do not care about security, and some users wanted to run some debugging read/write to secure region in u-boot shell.
Thanks
Tien Hock
Hi all!
We are developing a product around the rk3399 Theobroma Q7 module. For
power savings, we need S3 sleep (suspend-to-ram).
As far as I know, the heart of this is in ATF code. We have linux kernel
5.4, which starts the process nicely, drives down all the other cores
and finally calls for the psci suspend. We have wakeup on irq, and it
sure wakes up, but does a reset from the very beginning. So no context
saving resume.
I have tried the newest on the ATF git, with a newish mainline uboot. I
suppose the role of uboot is not that important here.
What should I look at to find the problem? Has someone got the Q7 module
done S3 ok?
Finally, how do I get some debug uart output from ATF code?
Thanks for any hints!
Mika Penttilä
Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 1 of 1 defect(s)
** CID 370380: Code maintainability issues (UNUSED_VALUE)
/plat/xilinx/versal/pm_service/pm_svc_main.c: 96 in pm_setup()
________________________________________________________________________________________________________
*** CID 370380: Code maintainability issues (UNUSED_VALUE)
/plat/xilinx/versal/pm_service/pm_svc_main.c: 96 in pm_setup()
90 int status, ret = 0;
91
92 status = pm_ipi_init(primary_proc);
93
94 if (status < 0) {
95 INFO("BL31: PM Service Init Failed, Error Code %d!\n", status);
>>> CID 370380: Code maintainability issues (UNUSED_VALUE)
>>> Assigning value from "status" to "ret" here, but that stored value is overwritten before it can be used.
96 ret = status;
97 } else {
98 pm_up = true;
99 }
100
101 /*
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u15810271.ct.sendgrid.net/ls/click?upn=HRESupC-2F2Czv4BOaCWWCy7my0P…
Hi,
Just my two cents:
- I suggest using $() instead of the backtick operator to enhance readability. This means f=`git rev-parse --git-dir` becomes f=$(git rev-parse --git-dir)
- use {} to group commands instead of () (no sub-shell is needed)
- stop processing if curl fails (hence second {} block)
- if the repo path has spaces, then some quotes are missing
So finally the command would become:
git clone --recurse-submodules https://git.trustedfirmware.org/hafnium/hafnium.git && { cd hafnium && f="$(git rev-parse --git-dir)"; curl -Lo "$f/hooks/commit-msg" https://review.trustedfirmware.org/tools/hooks/commit-msg && { chmod +x "$f/hooks/commit-msg"; git submodule --quiet foreach "cp \"\$toplevel/$f/hooks/commit-msg\" \"\$toplevel/$f/modules/\$path/hooks/commit-msg\"" ; } ; }
/George
-----Original Message-----
From: Hafnium <hafnium-bounces(a)lists.trustedfirmware.org> On Behalf Of Olivier Deprez via Hafnium
Sent: 21 April 2021 19:12
To: Rebecca Cran <rebecca(a)bsdio.com>; hafnium(a)lists.trustedfirmware.org
Subject: Re: [Hafnium] Getting Started page: problem with the command under "Getting the source code"
Hi,
Ah sorry for that; looks like there's some variable escape problem.
I tried this with success, let me know if it works for you. I will update the doc page then.
git clone --recurse-submodules https://git.trustedfirmware.org/hafnium/hafnium.git && (cd hafnium && f=`git rev-parse --git-dir`; curl -Lo $f/hooks/commit-msg https://review.trustedfirmware.org/tools/hooks/commit-msg; chmod +x $f/hooks/commit-msg; git submodule --quiet foreach "cp \$toplevel/$f/hooks/commit-msg \$toplevel/$f/modules/\$path/hooks/commit-msg")
If you don't require the git hooks a simpler way to clone the project can be:
git clone "https://review.trustedfirmware.org/hafnium/hafnium"; cd hafnium git submodule update --init
Regards,
Olivier.
________________________________________
From: Rebecca Cran <rebecca(a)bsdio.com>
Sent: 21 April 2021 16:33
To: Olivier Deprez; hafnium(a)lists.trustedfirmware.org
Subject: Re: [Hafnium] Getting Started page: problem with the command under "Getting the source code"
It now exits with the message:
cp: cannot stat '/home/rebecca/src/uefi/tmp/hafnium//hooks/commit-msg':
No such file or directory
fatal: run_command returned non-zero status for driver/linux .
--
Rebecca Cran
On 4/21/21 2:23 AM, Olivier Deprez wrote:
> Hi Rebecca,
>
> Thanks for reporting.
>
> Can you try with the updated command:
> https://review.trustedfirmware.org/plugins/gitiles/hafnium/hafnium/+/r
> efs/changes/31/9731/1/docs/GettingStarted.md
>
> Thanks, Olivier.
>
>
> ________________________________________
> From: Hafnium <hafnium-bounces(a)lists.trustedfirmware.org> on behalf of
> Rebecca Cran via Hafnium <hafnium(a)lists.trustedfirmware.org>
> Sent: 21 April 2021 04:39
> To: hafnium(a)lists.trustedfirmware.org
> Subject: [Hafnium] Getting Started page: problem with the command under "Getting the source code"
>
> On the Getting Started document
> (https://review.trustedfirmware.org/plugins/gitiles/hafnium/hafnium/+/
> HEAD/docs/GettingStarted.md) there's a command listed to get the
> source code:
>
> git clone --recurse-submodules
> https://git.trustedfirmware.org/hafnium/hafnium.git && (cd hafnium &&
> f=`git rev-parse --git-dir`/hooks/commit-msg ; curl -Lo $f
> https://review.trustedfirmware.org/tools/hooks/commit-msg ; chmod +x
> $f ; for m in `git rev-parse --git-dir`/modules/*; do cp $f
> $m/hooks/commit-msg; done)
>
>
> However, on my system it's erroring out because the 'hooks' directory
> it tries to write to doesn't exist:
>
> % Total % Received % Xferd Average Speed Time Time Time
> Current
> Dload Upload Total Spent Left Speed
> 100 2174 100 2174 0 0 4221 0 --:--:-- --:--:--
> --:--:-- 4221
> cp: cannot create regular file '.git/modules/driver/hooks/commit-msg':
> No such file or directory
> cp: cannot create regular file '.git/modules/project/hooks/commit-msg':
> No such file or directory
> cp: cannot create regular file
> '.git/modules/third_party/hooks/commit-msg': No such file or directory
>
>
> --
> Rebecca Cran
>
> --
> Hafnium mailing list
> Hafnium(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/hafnium
>
--
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Hafnium(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/hafnium
This event has been canceled with this note:
"Cancelled per Joanna"
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
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When: Thu Apr 22, 2021 8am – 9am Mountain Standard Time - Phoenix
Calendar: tf-a(a)lists.trustedfirmware.org
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Hi Everyone,
I am cancelling this weeks TF-A Tech Forum as I don’t have any areas to present/discuss. I would encourage any contributors that wants to present or lead a discussion subject to please let me know as we are always looking for topics of interest to the project community to run sessions on.
Cancellations of the calendar invite will come from trustedformware.org.
Thanks
Joanna
Hi
There is a discussion started by Harb from Ampere about standardizing
information from secure firmware to BL33: look at HOB in the object.
A side aspect of the HOB is: DT shall be used wisely for things that are
really static. Dynamic (such as plugged DIMMs) or configurable aspects
(secure memory size) should be controllable by a single authoritative
entity. On a number of platforms, the definition of secure memory size is
"copied" in at least for different independent projects which make it a
nightmare for product makers to choose a size for the trusted application
they want to onboard.
Cheers
FF
On Tue, 20 Apr 2021 at 07:49, Jan Kiszka via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> On 20.04.21 02:51, Samuel Holland wrote:
> > On 4/19/21 11:11 AM, Jan Kiszka via TF-A wrote:
> >> On 19.04.21 17:21, Michal Simek wrote:
> >>> On 4/18/21 8:44 PM, Jan Kiszka wrote:
> >>>> when SPD or DEBUG is enabled, TF-A is moved to RAM on the zynqmp (as
> it
> >>>> longer fits into OCM). U-Boot happens to avoid that region, but the
> >>>> kernel's DTB has no reservation entry, and Linux will trigger an
> >>>> exception when accessing that region during early boot.
> >>>>
> >>>> Can we improve this - without requiring the user to manually add a
> >>>> reservation to the DTB? Should we unconditionally reserve
> >>>> 0x1000..0x7ffff in all BL33 DTBs? Or is there a chance to communicate
> >>>> that need? Or some way to detect in BL33 whether it is needed?
> >>>
> >>> Normally this ddr region should be also protected by security IPs that
> >>> NS has no access there.
> >>> It means in Xilinx flow this can be (and should be) propagated via
> >>> device-tree generator to final DTS file that you don't need to touch it
> >>> by hand.
> >>> I am not aware about any way that NS can query secure world what memory
> >>> can be used. And not sure if there is any standard way to do so.
> >>>
> >>
> >> OK, understood. But then, to be safe, shouldn't the upstream "static"
> >> default DT contain an exclusion of that region so that it won't get
> >> stuck if it is in use? Would block half a meg, but when you have a
> >> custom platform that does not need that, you can and will provide your
> >> own DT anyway.
> >
> > Ideally, the static DTS is a description of the hardware only, and not
> > of runtime constraints imposed by the firmware. If BL31 needs to reserve
> > some memory, it can add that reservation to the DTB at runtime. The
> > fdt_add_reserved_memory() function is available for this purpose. For an
> > example, see the code used by the rpi4[0] or sun50i_h616[1] platforms.
> >
> > If you later load a DTB from disk for use by Linux, you will need to
> > copy the reserved-memory nodes from the U-Boot DTB to the loaded DTB.
> >
>
> I know the RPi4 model (just had to debug it [3]). But I wonder if that
> is possible on the zynqmp as well. Are we passing a DT to BL33 here
> already and, thus, could inject that reservation?
>
> Jan
>
> > Regards,
> > Samuel
> >
> > [0]:
> >
> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/rpi/r…
> > [1]:
> >
> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/allwi…
> >
>
> [3] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/9316
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi,
This looks promising. Can you also create a list of guidelines resulting from the analysis? We can then roll them up as coding guidelines or design guidelines or to-do for platforms.
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Zelalem Aweke via TF-A
Sent: Friday, April 16, 2021 8:15 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] [RFC] TF-A threat model
External email: Use caution opening links or attachments
Hi All,
We are releasing the first TF-A threat model document. This release provides the baseline for future updates to be applied as required by developments to the TF-A code base. Please review the document provide comments here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/9627<https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Freview.tr…>.
Thanks,
Zelalem
Hi,
>From git log g12a platform was first introduced in 2019 and never has any further changes, also there is no documentation for this platform, so from platform perspective not sure if you are doing everything right or not ?
However, i have some generic comments
1. There is no such macro DISABLE_PEDANTIC
2. Which CPU you have in Odroid-C4 boards(is it Cortext-A55?), You probably need to add cpu lib file in platform.mk file
In file plat/amlogic/g12a/platform.mk
BL31_SOURCES += lib/cpus/aarch64/cortex_a53.S \
lib/cpus/aarch64/cortex_a55.S
thanks
Manish
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Matwey V. Kornilov via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 19 April 2021 16:47
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] platform g12a: CSSERT: File lib/cpus/aarch64/cpu_helpers.S Line 00035
Hello,
Sorry, if this is the wrong place to ask.
I am trying to run ATF v2.4 for platform g12a on the Odroid-C4 board.
I've built ATF as the following
make DISABLE_PEDANTIC=1 DEBUG=1 PLAT=g12a
Unfortunately, the only thing I see in the console when BL31 is
supposed to run is
CSSERT: File lib/cpus/aarch64/cpu_helpers.S Line 00035
Is there any chance to figure out what is wrong?
--
With best regards,
Matwey V. Kornilov
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi all,
when SPD or DEBUG is enabled, TF-A is moved to RAM on the zynqmp (as it
longer fits into OCM). U-Boot happens to avoid that region, but the
kernel's DTB has no reservation entry, and Linux will trigger an
exception when accessing that region during early boot.
Can we improve this - without requiring the user to manually add a
reservation to the DTB? Should we unconditionally reserve
0x1000..0x7ffff in all BL33 DTBs? Or is there a chance to communicate
that need? Or some way to detect in BL33 whether it is needed?
Jan
Hello,
Sorry, if this is the wrong place to ask.
I am trying to run ATF v2.4 for platform g12a on the Odroid-C4 board.
I've built ATF as the following
make DISABLE_PEDANTIC=1 DEBUG=1 PLAT=g12a
Unfortunately, the only thing I see in the console when BL31 is
supposed to run is
CSSERT: File lib/cpus/aarch64/cpu_helpers.S Line 00035
Is there any chance to figure out what is wrong?
--
With best regards,
Matwey V. Kornilov
Thanks to all those who attended the Tech Forum today!
It’s become apparent that the initial 2 week deadline for alternative proposals or implementations is too short, so – as agreed – we’ll push the deadline for the investigation period to the end of March. This period is dedicated to evaluating the changelog automation proposal made, or to identifying alternative solutions. If you have an alternative proposal, any proof-of-concept tooling would be highly appreciated so we can get a clear idea of what sort of work and maintenance is going to be involved.
If you do find a solution you wish to propose, please give it just a short name (e.g. “Update it manually”) and make it obvious you want to propose it formally – I’ll collect up the proposals made on the mailing list thread at the end of March and set up a Wiki poll so we can get a clear picture of where the community wants to take this.
Chris
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Chris Kay via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Chris Kay <Chris.Kay(a)arm.com>
Date: Thursday, 11 February 2021 at 13:59
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Adoption of Conventional Commits
Hi all,
Recently we had an internal discussion on the merits of introducing semantics to commit messages pushed to the main TF-A repository, the conclusion being that we would look to adopting the Conventional Commits<https://www.conventionalcommits.org/en/v1.0.0/> specification in the near future. There was one major reason for this, which was to help us in automating the changelog in future releases, but it might also help us to dramatically reduce the overall amount of work needed to make a formal release in the future.
This requires some buy-in (or buy-out, in this case) from maintainers because - even though it’s to only a relatively minor extent - it does involve an adjustment to everybody’s workflow. Notably, commit messages will be expected to adopt the structure defined by the specification, which will be enforced by the CI. Most commits that go upstream today adhere to “something that looks like Conventional Commits”, so the change is not exactly sweeping, but any change has the potential be an inconvenience.
With that in mind, I propose the following:
* We collectively adopt the specification, enforced only for @arm.com contributors until such a time that the majority of maintainers are familiar with the new demands
* We suggest - in the prerequisites documentation - the installation of two helper tools:
* Commitizen<https://github.com/commitizen/cz-cli>
* Commitlint<https://github.com/conventional-changelog/commitlint>
Installation of these tools will be optional, but I believe they can help with the transition. In the patches currently in review, they are installed as Git hooks automatically upon execution of npm install, so it requires no manual installation or configuration (other than a relatively up-to-date Node.js installation).
You’ll find the patches here<https://review.trustedfirmware.org/q/topic:%22ck%252Fconventional-commits%2…>, and specifically the changes to the prerequisites documentation here<https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/8224/1/docs/…>. Feel free to review these changes if you have comments specifically on their implementation.
Let me know if you have any questions or concerns. If everybody’s on board, we can look to have this upstreamed shortly.
Chris
Hi All,
We are releasing the first TF-A threat model document. This release provides the baseline for future updates to be applied as required by developments to the TF-A code base. Please review the document provide comments here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/9627.
Thanks,
Zelalem
Hi
Open System Firmware and Trusted Firmware communities have common interests
in driving *some* firmware discussions because upstream projects like EDK2,
U-Boot and Linux boot greatly benefit from common approaches regardless of
processor architecture and early firmware components.
The discussion on passing metadata between early firmware components and
from early firmware to EDK2/U-Boot/LinuxBoot is typically such a topic.
EDK2 is the only project that has defined metadata in the form of Platform
Initialization HOBs (chapter 5 of PI spec).
U-Boot and LinuxBoot have platform specific techniques to consume that
metadata.
Let's make sure that at least there is common solution for those two and
hope that the result is enticing enough that EDK2 decide to leverage the
result one way or the other.
Here is a patched repost of the state of discussion after last Trusted
Substrate call:
Topics where there seem to be consensus
- Scope include diverse firmware flows (U-Boot/SPL, TFA, CoreBoot…) on
different architectures (Arm, RiscV)
- Definitions: The Hand Over Function is the firmware component that
hands off to the booted payload = {OS/Hypervisor/Grub/Shim}.
- Hand Over Function can be EDK2, U-Boot or LinuxBoot.
- The HOF, through ACPI or DT is responsible to describe what shall be
controlled and partly how (some parameters)
- *There is information that can only be discovered at runtime by
diverse early firmware components and needs to be conveyed through the HOF
to the booted payload.*
- The proposal is to convey that dynamic information in the form of
HandOverBlocks (HOBs - generic idea, not the EDK2 construct) whose
format is yet to be defined and built as a linked list of objects. The
other proposal to use call backs (mmc calls or equivalent) from HOF to
firmware is rejected. In Arm architecture, that choice does not preclude
some firmware components to use SCMI calls into SCP to obtain authoritative
information.
- The firmware components shall not care about what is the actual HOF:
the format is standard regardless if HOF is EDK2, U-Boot or LinuxBoot.
In TF-A words, the HOBs become part of the input ABI for BL33. In the
best world, it should be possible for the platform "buyer" to choose the
HOF.
Characteristics to consider about HOBs:
- HOBs can be built by very early components and must fit into highly
constrained SRAM
- A HOB may be passed between different firmware components, secure and
non-secure.
- A HOB can be built by secure and non-secure firmware components
- An information can have a single format: no alternative representation
is allowed. In other words if the information is passed as a data structure
it cannot be represented by a DT fragment by another implementation and
conversely.
Topics that need more discussion
- HOBs need a way to be identified: UUID, ID, hybrid (like Platform
Initialization).
*My views: the hybrid allows constraints firmware components to be using
simple IDs and richer components may want leverage UUIDs (same as Platform
Initialization).*
- HOB format: binary information; just static structure, flatten device
tree fragments/overlays or even CBOR.
*My views: again hybrid approach seem very efficient. Static structures for
memory information, DT fragment for device assignment (for non-secure
partitions or for secure world / secure partitions). Typically I would
imagine a UUID HOB with a DT fragment seems just good. This is actually
implemented like that with Platform Initialization:*
*HOBs are identified by a simple ID, out of IDs are
EFI_HOB_RESOURCE_DESCRIPTOR for DRAM description and EFI_HOB_GUID_TYPE that
contains something identified by a GUID. There is a GUID used in the
context of EDK2 to actually contain a DT fragment today.*
*As an open specification that allows extension, there shall be a mandate
to publish an open specification of any extension.*
On Fri, 16 Apr 2021 at 07:51, François Ozog via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> +tf.org as the discussion evolved to a topic discussed there.
>
> Le ven. 16 avr. 2021 à 01:25, Zimmer, Vincent <vincent.zimmer(a)intel.com>
> a écrit :
>
>>
>>
>> For the wayback machine, the design of HOB’s dates back to early 2000’s.
>>
>>
>>
>>
>>
>> The HOB defin was part of the Intel Framework specs & it was made public
>> in 2003 through a click-through, as folks noted. HOBs became part of the
>> UEFI Forum Platform Initialization (PI) spec in 2006. Essentially PI 1.0
>> absorbed most of the Framework 0.9x specs (sans datahub, CSM).
>>
>> from https://link.springer.com/book/10.1007/978-1-4842-0070-4
>>
>>
>>
>> IMHO the biggest bug on the present Type Length Value (TLV)-based HOB
>> design entails the “L” of the TLV, namely the 16-bit length limitation on
>> the size of a specific HOB. Servers often bump into this limitation today
>> given the amount of state discovered in these early initialization flows.
>> The use of GUID’s w/o strings is also a usability challenge, I’d agree,
>> that any new design can address.
>>
>>
>>
>> Going forward
>>
>> The more recent proposed use of HOB's for the generic payload interface
>> https://github.com/universalpayload/documentation launching was more for
>> convenience since it's a simple TLV encoded mechanism and there are parsing
>> libraries already in the wild. But the use of HOB’s versus DT versus ….
>> for the inargs of the payload is definitely open for discussion/change in
>> the design. The earlier thread suggestions of CBOR/8949
>> https://www.rfc-editor.org/rfc/rfc8949.html from Francois/Nate is
>> interesting. We can update the already open issue on this topic
>> https://github.com/universalpayload/documentation/issues/9 with some of
>> these thoughts and build upon the sentiments Ron shared earlier on the
>> topic.
>>
>>
>>
>> And regarding the payload specification
>> https://universalpayload.github.io/documentation/ mentioned above, I’m
>> happy to present on this design effort in an upcoming OSF meeting,
>> including how payloads may relate to the OSF workstream. The payload
>> design is intended to be an open process with a code-first workflow that
>> doesn’t tie itself to any specific bootloader design, as demonstrated by
>> the different bootloaders and payloads ported at
>> https://github.com/universalpayload. Although there isn’t a U-Boot
>> example ported (I thought I heard mention of U-boot in this thread or
>> meeting?), addressing the needs of U-boot and other *boot solutions (e.g.,
>> oreboot) is definitely part of the design scope intent, too.
>>
>>
>>
>> Thanks,
>>
>>
>>
>> Vincent
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: OCP-OSF(a)OCP-All.groups.io <OCP-OSF(a)OCP-All.groups.io> On Behalf Of
>> ron minnich
>> Sent: Thursday, April 15, 2021 3:14 PM
>> To: Desimone, Nathaniel L <nathaniel.l.desimone(a)intel.com>
>> Cc: OCP-OSF(a)OCP-All.groups.io; Boot Architecture Mailman List <
>> boot-architecture(a)lists.linaro.org>; Leif Lindholm <leif(a)nuviainc.com>
>> Subject: Re: [OCP-OSF] Firmware: Sustainability vs planned obsolescence
>>
>>
>>
>> actually isn't device tree a 1980s design :-)
>>
>>
>>
>> anyway, as long as we can hit the things I care so much about,
>>
>>
>>
>> self describing
>>
>> alignment independent
>>
>> endian independent
>>
>> names not magic numbers (I mean, you want to put a UUID in there too,
>> fine, but I doubt a human-readable string will kill us on space)
>>
>>
>>
>> it can be anything you all think best.
>>
>>
>>
>> On Thu, Apr 15, 2021 at 2:49 PM Desimone, Nathaniel L <
>> nathaniel.l.desimone(a)intel.com> wrote:
>>
>> >
>>
>> > On Thu, Apr 15, 2021 at 1:29 -0700, ron minnich wrote:
>>
>> >
>>
>> > >I'd rather not take HOB as a given without considering alternatives.
>>
>> > >It's a very 1990s design.
>>
>> >
>>
>> > Device tree is also a very early 90s design for that matter. If we are
>> talking about clean slate design, how about something actually new and
>> modern like RFC 8949?
>>
>> >
>>
>> > From a practical standpoint I don't see HOBs going away very soon but
>> I'm open to possibility thinking on a long term basis.
>>
>> >
>>
>> >
>>
>> >
>>
>> >
>>
>>
>>
>>
>>
>>
>>
>>
>> _._,_._,_
>> ------------------------------
>> Groups.io Links:
>>
>> You receive all messages sent to this group.
>>
>> View/Reply Online (#149)
>> <https://OCP-All.groups.io/g/OCP-OSF/message/149> | Reply To Group
>> <OCP-OSF@OCP-All.groups.io?subject=Re:%20Re%3A%20%5BOCP-OSF%5D%20Firmware%3A%20Sustainability%20vs%20planned%20obsolescence>
>> | Reply To Sender
>> <vincent.zimmer@intel.com?subject=Private:%20Re:%20Re%3A%20%5BOCP-OSF%5D%20Firmware%3A%20Sustainability%20vs%20planned%20obsolescence>
>> | Mute This Topic <https://groups.io/mt/81937262/675475> | New Topic
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>> [francois.ozog(a)linaro.org]
>> _._,_._,_
>>
>> --
> François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
> T: +33.67221.6485
> francois.ozog(a)linaro.org | Skype: ffozog
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi Rebecca,
qemu is currently not supported for use with the SPM at S-EL2.
The two available options are FVP (https://trustedfirmware-a.readthedocs.io/en/latest/components/secure-partit…)
or Total Compute platform (https://gitlab.arm.com/arm-reference-solutions/arm-reference-solutions-docs…)
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Rebecca Cran via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 16 April 2021 00:02
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Problems building for qemu with SPM (S-EL2) support
I'm having problems building TF-A with SPM/S-EL2 support. I can build
with PLAT=fvp fine, but building with PLAT=qemu results in the error:
LD
/home/rebecca/src/arm-trusted-firmware/build/qemu/release/bl31/bl31.elf
/home/rebecca/gcc-arm-10.2-2020.11-x86_64-aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-ld:
/home/rebecca/src/arm-trusted-firmware/build/qemu/release/bl31/spmd_main.o:
in function `spmd_setup':
spmd_main.c:(.text.spmd_setup+0x74): undefined reference to
`plat_spm_core_manifest_load'
spmd_main.c:(.text.spmd_setup+0x74): relocation truncated to fit:
R_AARCH64_CALL26 against undefined symbol `plat_spm_core_manifest_load'
make: *** [Makefile:1136:
/home/rebecca/src/arm-trusted-firmware/build/qemu/release/bl31/bl31.elf]
Error 1
The command line I'm using is:
make PLAT=qemu DEBUG=0 \
CROSS_COMPILE=~/gcc-arm-10.2-2020.11-x86_64-aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-
\
SPD=spmd CTX_INCLUDE_EL2_REGS=1 BL32=bl32.bin BL33=bl33.bin \
SP_LAYOUT_FILE=sp_layout.json ARM_ARCH_MINOR=4 all fip
Adding the following files to BL31_SOURCES in plat/qemu/platform.mk
resolves the problem, but I suspect that's not the correct solution?
plat/common/plat_spmd_manifest.c
common/fdt_wrappers.c
--
Rebecca Cran
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
+tf.org as the discussion evolved to a topic discussed there.
Le ven. 16 avr. 2021 à 01:25, Zimmer, Vincent <vincent.zimmer(a)intel.com> a
écrit :
>
>
> For the wayback machine, the design of HOB’s dates back to early 2000’s.
>
>
>
>
>
> The HOB defin was part of the Intel Framework specs & it was made public
> in 2003 through a click-through, as folks noted. HOBs became part of the
> UEFI Forum Platform Initialization (PI) spec in 2006. Essentially PI 1.0
> absorbed most of the Framework 0.9x specs (sans datahub, CSM).
>
> from https://link.springer.com/book/10.1007/978-1-4842-0070-4
>
>
>
> IMHO the biggest bug on the present Type Length Value (TLV)-based HOB
> design entails the “L” of the TLV, namely the 16-bit length limitation on
> the size of a specific HOB. Servers often bump into this limitation today
> given the amount of state discovered in these early initialization flows.
> The use of GUID’s w/o strings is also a usability challenge, I’d agree,
> that any new design can address.
>
>
>
> Going forward
>
> The more recent proposed use of HOB's for the generic payload interface
> https://github.com/universalpayload/documentation launching was more for
> convenience since it's a simple TLV encoded mechanism and there are parsing
> libraries already in the wild. But the use of HOB’s versus DT versus ….
> for the inargs of the payload is definitely open for discussion/change in
> the design. The earlier thread suggestions of CBOR/8949
> https://www.rfc-editor.org/rfc/rfc8949.html from Francois/Nate is
> interesting. We can update the already open issue on this topic
> https://github.com/universalpayload/documentation/issues/9 with some of
> these thoughts and build upon the sentiments Ron shared earlier on the
> topic.
>
>
>
> And regarding the payload specification
> https://universalpayload.github.io/documentation/ mentioned above, I’m
> happy to present on this design effort in an upcoming OSF meeting,
> including how payloads may relate to the OSF workstream. The payload
> design is intended to be an open process with a code-first workflow that
> doesn’t tie itself to any specific bootloader design, as demonstrated by
> the different bootloaders and payloads ported at
> https://github.com/universalpayload. Although there isn’t a U-Boot
> example ported (I thought I heard mention of U-boot in this thread or
> meeting?), addressing the needs of U-boot and other *boot solutions (e.g.,
> oreboot) is definitely part of the design scope intent, too.
>
>
>
> Thanks,
>
>
>
> Vincent
>
>
>
>
>
> -----Original Message-----
> From: OCP-OSF(a)OCP-All.groups.io <OCP-OSF(a)OCP-All.groups.io> On Behalf Of
> ron minnich
> Sent: Thursday, April 15, 2021 3:14 PM
> To: Desimone, Nathaniel L <nathaniel.l.desimone(a)intel.com>
> Cc: OCP-OSF(a)OCP-All.groups.io; Boot Architecture Mailman List <
> boot-architecture(a)lists.linaro.org>; Leif Lindholm <leif(a)nuviainc.com>
> Subject: Re: [OCP-OSF] Firmware: Sustainability vs planned obsolescence
>
>
>
> actually isn't device tree a 1980s design :-)
>
>
>
> anyway, as long as we can hit the things I care so much about,
>
>
>
> self describing
>
> alignment independent
>
> endian independent
>
> names not magic numbers (I mean, you want to put a UUID in there too,
> fine, but I doubt a human-readable string will kill us on space)
>
>
>
> it can be anything you all think best.
>
>
>
> On Thu, Apr 15, 2021 at 2:49 PM Desimone, Nathaniel L <
> nathaniel.l.desimone(a)intel.com> wrote:
>
> >
>
> > On Thu, Apr 15, 2021 at 1:29 -0700, ron minnich wrote:
>
> >
>
> > >I'd rather not take HOB as a given without considering alternatives.
>
> > >It's a very 1990s design.
>
> >
>
> > Device tree is also a very early 90s design for that matter. If we are
> talking about clean slate design, how about something actually new and
> modern like RFC 8949?
>
> >
>
> > From a practical standpoint I don't see HOBs going away very soon but
> I'm open to possibility thinking on a long term basis.
>
> >
>
> >
>
> >
>
> >
>
>
>
>
>
>
>
>
> _._,_._,_
> ------------------------------
> Groups.io Links:
>
> You receive all messages sent to this group.
>
> View/Reply Online (#149) <https://OCP-All.groups.io/g/OCP-OSF/message/149>
> | Reply To Group
> <OCP-OSF@OCP-All.groups.io?subject=Re:%20Re%3A%20%5BOCP-OSF%5D%20Firmware%3A%20Sustainability%20vs%20planned%20obsolescence>
> | Reply To Sender
> <vincent.zimmer@intel.com?subject=Private:%20Re:%20Re%3A%20%5BOCP-OSF%5D%20Firmware%3A%20Sustainability%20vs%20planned%20obsolescence>
> | Mute This Topic <https://groups.io/mt/81937262/675475> | New Topic
> <https://OCP-All.groups.io/g/OCP-OSF/post>
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> <https://OCP-All.groups.io/g/OCP-OSF/leave/10214763/675475/1625423992/xyzzy>
> [francois.ozog(a)linaro.org]
> _._,_._,_
>
> --
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
>> Otherwise, we will begin adopting Conventional Commits in the CI at the beginning of April, pending full rollout for everybody in the next release.
IIRC, I already proposed another option that builds on the tagging mechanism from Conventional Commits. Did we document the objections somewhere? I remember, CC did get some "nays" on the wiki page. Were all those concerns resolved?
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Chris Kay via TF-A
Sent: Thursday, March 18, 2021 5:08 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Adoption of Conventional Commits
External email: Use caution opening links or attachments
Just a reminder to everybody that we're now most of the way through March, and therefore most of the way through the investigation period.
If anybody has any proposals they'd like to make, please do share them as soon as possible so that we have time to brainstorm and come to a conclusion. Otherwise, we will begin adopting Conventional Commits in the CI at the beginning of April, pending full rollout for everybody in the next release.
Chris
From: Chris Kay <Chris.Kay(a)arm.com<mailto:Chris.Kay@arm.com>>
Date: Thursday, 25 February 2021 at 17:30
To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Subject: Re: [TF-A] Adoption of Conventional Commits
Thanks to all those who attended the Tech Forum today!
It's become apparent that the initial 2 week deadline for alternative proposals or implementations is too short, so - as agreed - we'll push the deadline for the investigation period to the end of March. This period is dedicated to evaluating the changelog automation proposal made, or to identifying alternative solutions. If you have an alternative proposal, any proof-of-concept tooling would be highly appreciated so we can get a clear idea of what sort of work and maintenance is going to be involved.
If you do find a solution you wish to propose, please give it just a short name (e.g. "Update it manually") and make it obvious you want to propose it formally - I'll collect up the proposals made on the mailing list thread at the end of March and set up a Wiki poll so we can get a clear picture of where the community wants to take this.
Chris
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>> on behalf of Chris Kay via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Reply to: Chris Kay <Chris.Kay(a)arm.com<mailto:Chris.Kay@arm.com>>
Date: Thursday, 11 February 2021 at 13:59
To: "tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>" <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Subject: [TF-A] Adoption of Conventional Commits
Hi all,
Recently we had an internal discussion on the merits of introducing semantics to commit messages pushed to the main TF-A repository, the conclusion being that we would look to adopting the Conventional Commits<https://www.conventionalcommits.org/en/v1.0.0/> specification in the near future. There was one major reason for this, which was to help us in automating the changelog in future releases, but it might also help us to dramatically reduce the overall amount of work needed to make a formal release in the future.
This requires some buy-in (or buy-out, in this case) from maintainers because - even though it's to only a relatively minor extent - it does involve an adjustment to everybody's workflow. Notably, commit messages will be expected to adopt the structure defined by the specification, which will be enforced by the CI. Most commits that go upstream today adhere to "something that looks like Conventional Commits", so the change is not exactly sweeping, but any change has the potential be an inconvenience.
With that in mind, I propose the following:
* We collectively adopt the specification, enforced only for @arm.com contributors until such a time that the majority of maintainers are familiar with the new demands
* We suggest - in the prerequisites documentation - the installation of two helper tools:
* Commitizen<https://github.com/commitizen/cz-cli>
* Commitlint<https://github.com/conventional-changelog/commitlint>
Installation of these tools will be optional, but I believe they can help with the transition. In the patches currently in review, they are installed as Git hooks automatically upon execution of npm install, so it requires no manual installation or configuration (other than a relatively up-to-date Node.js installation).
You'll find the patches here<https://review.trustedfirmware.org/q/topic:%22ck%252Fconventional-commits%2…>, and specifically the changes to the prerequisites documentation here<https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/8224/1/docs/…>. Feel free to review these changes if you have comments specifically on their implementation.
Let me know if you have any questions or concerns. If everybody's on board, we can look to have this upstreamed shortly.
Chris
I'm having problems building TF-A with SPM/S-EL2 support. I can build
with PLAT=fvp fine, but building with PLAT=qemu results in the error:
LD
/home/rebecca/src/arm-trusted-firmware/build/qemu/release/bl31/bl31.elf
/home/rebecca/gcc-arm-10.2-2020.11-x86_64-aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-ld:
/home/rebecca/src/arm-trusted-firmware/build/qemu/release/bl31/spmd_main.o:
in function `spmd_setup':
spmd_main.c:(.text.spmd_setup+0x74): undefined reference to
`plat_spm_core_manifest_load'
spmd_main.c:(.text.spmd_setup+0x74): relocation truncated to fit:
R_AARCH64_CALL26 against undefined symbol `plat_spm_core_manifest_load'
make: *** [Makefile:1136:
/home/rebecca/src/arm-trusted-firmware/build/qemu/release/bl31/bl31.elf]
Error 1
The command line I'm using is:
make PLAT=qemu DEBUG=0 \
CROSS_COMPILE=~/gcc-arm-10.2-2020.11-x86_64-aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-
\
SPD=spmd CTX_INCLUDE_EL2_REGS=1 BL32=bl32.bin BL33=bl33.bin \
SP_LAYOUT_FILE=sp_layout.json ARM_ARCH_MINOR=4 all fip
Adding the following files to BL31_SOURCES in plat/qemu/platform.mk
resolves the problem, but I suspect that's not the correct solution?
plat/common/plat_spmd_manifest.c
common/fdt_wrappers.c
--
Rebecca Cran
Hi Jan,
On Sat, Apr 10, 2021 at 1:18 PM Jan Kiszka via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> On 09.04.21 14:56, Jan Kiszka wrote:
> > Hi all,
> >
> > I'm currently debugging sporadic lockups in TF-A when calling the system
> > reset hook of OP-TEE: opteed_system_reset() gets stuck on
> > opteed_synchronous_sp_entry(), and the thread_system_reset_handler of
> > OP-TEE is not invoked (I left a debug output on the OP-TEE side).
> > Platform is k3, target hardware our IOT2050 device. I was using today's
> > master of TF-A and OP-TEE, but also older versions of both.
> >
> > What could cause this? I would assume that TF-A and OP-TEE are protected
> > against overwriting of the non-secure world and we would see exceptions
> > in case some reservation is not properly set, possibly misleading Linux.
> >
>
> Turned out that we had a bug in our device tree: "reserved_memory",
> rather than "reserved-memory". That caused Linux to ignore the RAM
> reservation, eventually accessing the memory that OP-TEE is using.
>
> But that still does not explain why the secured memory is left behind
> unsecured. Who is responsible for that, TF-A or the TEE itself?
This might be memory reserved for the static shared memory pool used
when communicating between Linux normal world and OP-TEE in secure
world.
If that's the case it's normal that the memory is accessible from
Linux, however if Linux uses it for other purposes too there will be
memory corruptions.
Cheers,
Jens
Hi,
From TF-A project point of view, we prefer to use existing mechanism to pass parameters across boot stages using linked list of tagged elements (as suggested by Julius). It has support for both generic and SiP-specific tags. Having said that, it does not stop partners to introduce new mechanisms suitable for their usecase in platform port initially and later move to generic code if its suitable for other platforms.
To start with, Ampere can introduce a platform specific implementation of memory tag(speed/NUMA topology etc) which can be evaluated and discussed for generalization in future. The tag will be populated in BL2 stage and can be forwarded to further stages(and to BL33) by passing the head of list pointer in one of the registers. Initially any register can be used but going forward a standardization will be needed.
The U-boot bloblist mentioned by Simon is conceptually similar to what TF-A is using, if there is consensus of using bloblist/taglist then TF-A tag list may be enhanced to take best of both the implementations.
One of the potential problems of having structure used in different projects is maintainability, this can be avoided by having a single copy of these structures in TF-A (kept inside "include/export" which intended to be used by other projects.)
Regarding usage of either UUID or tag, I echo the sentiments of Simon and Julius to keep it simple and use tag values.
Looking forward to having further discussions on zoom call today.
Thanks
Manish P
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 25 March 2021 02:43
To: Simon Glass <sjg(a)chromium.org>
Cc: Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; U-Boot Mailing List <u-boot(a)lists.denx.de>; Paul Isaac's <paul.isaacs(a)linaro.org>; Ron Minnich <rminnich(a)google.com>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
Just want to point out that TF-A currently already supports a (very simple) mechanism like this:
https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…
It's just a linked list of tagged elements. The tag space is split into TF-A-wide generic tags and SiP-specific tags (with plenty of room to spare if more areas need to be defined -- a 64-bit tag can fit a lot). This is currently being used by some platforms that run coreboot in place of BL1/BL2, to pass information from coreboot (BL2) to BL31.
I would echo Simon's sentiment of keeping this as simple as possible and avoiding complicated and bloated data structures with UUIDs. You usually want to parse something like this as early as possible in the passed-to firmware stage, particularly if the structure encodes information about the debug console (like it does for the platforms I mentioned above). For example, in BL31 this basically means doing it right after moving from assembly to C in bl31_early_platform_setup2() to get the console up before running anything else. At that point in the BL31 initialization, the MMU and caches are disabled, so data accesses are pretty expensive and you don't want to spend a lot of parsing effort or calculate complicated checksums or the like. You just want something extremely simple where you ideally have to touch every data word only once.
On Wed, Mar 24, 2021 at 5:06 PM Simon Glass via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
Hi Harb,
On Wed, 24 Mar 2021 at 11:39, Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com<mailto:abdulhamid@os.amperecomputing.com>> wrote:
Hello Folks,
Appreciate the feedback and replies on this. Glad to see that there is interest in this topic. 😊
I try to address the comments/feedback from Francois and Simon below….
@François Ozog<mailto:francois.ozog@linaro.org> – happy to discuss this on a zoom call. I will make that time slot work, and will be available to attend April 8, 4pm CT.
Note that I’m using the term “HOB” here more generically, as there are typically vendor specific structures beyond the resource descriptor HOB, which provides only a small subset of the information that needs to be passed between the boot phases.
The whole point here is to provide mechanism to develop firmware that we can build ARM Server SoC’s that support *any* BL33 payload (e.g. EDK2, AptioV, CoreBoot, and maybe even directly boot strapping LinuxBoot at some point). In other-words, we are trying to come up with a TF-A that would be completely agnostic to the implementation of BL33 (i.e. BL33 is built completely independently by a separate entity – e.g. an ODM/OEM).
Keep in mind, in the server/datacenter market segment we are not building vertically integrated systems with a single entity compiling firmware/software stacks like most folks in TF-A have become use to. There are two categories of higher level firmware code blobs in the server/datacenter model:
1. “SoC” or “silicon” firmware – in TF-A this may map to BL1, BL2, BL31, and *possibly* one or more BL32 instances
2. “Platform” or “board” firmware – in TF-A this may map to BL33 and *possibly* one or more BL32 instances.
Even the platform firmware stack could be further fragmented by having multiple entities involved in delivering the entire firmware stack: IBVs, ODMs, OEMs, CSPs, and possibly even device vendor code.
To support a broad range of platform designs with a broad range of memory devices, we need a crisp and clear contract between the SoC firmware that initializes memory (e.g. BL2) and how that platform boot firmware (e.g. BL33) gathers information about what memory that was initialized, at what speeds, NUMA topology, and many other relevant information that needs to be known and comprehended by the platform firmware and eventually by the platform software.
I understand the versatility of DT, but I see two major problems with DT:
* DT requires more complicated parsing to get properties, and even more complex to dynamically set properties – this HOB structures may need to be generated in boot phases where DDR is not available, and therefore we will be extremely memory constrained.
* DT is probably overkill for this purpose – We really just want a list of pointers to simple C structures that code cast (e.g. JEDEC SPD data blob)
I think that we should not mix the efforts around DT/ACPI specs with what we are doing here, because those specs and concepts were developed for a completely different purpose (i.e. abstractions needed for OS / RTOS software, and not necessarily suitable for firmware-to-firmware hand-offs).
Frankly, I would personally push back pretty hard on defining SMC’s for something that should be one way information passing. Every SMC we add is another attack vector to the secure world and an increased burden on the folks that have to do security auditing and threat analysis. I see no benefit in exposing these boot/HOB/BOB structures at run-time via SMC calls.
Please do let me know if you disagree and why. Look forward to discussing on this thread or on the call.
@Simon Glass<mailto:sjg@chromium.org> - Thanks for the pointer to bloblist. I briefly reviewed and it seems like a good baseline for what we may be looking for.
That being said, I would say that there is some benefit in having some kind of unique identifiers (e.g. UUID or some unique signature) so that we can tie standardized data structures (based on some future TBD specs) to a particular ID. For example, if the TPM driver in BL33 is looking for the TPM structure in the HOB/BOB list, and may not care about the other data blobs. The driver needs a way to identify and locate the blob it cares about.
The tag is intended to serve that purpose, although perhaps it should switch from an auto-allocating enum to one with explicit values for each entry and a range for 'local' use.
I guess we can achieve this with the tag, but the problem with tag when you have eco-system with a lot of parties doing parallel development, you can end up with tag collisions and folks fighting about who has rights to what tag values. We would need some official process for folks to register tags for whatever new structures we define, or maybe some tag range for vendor specific structures. This comes with a lot of pain and bureaucracy. On the other hand, UUID has been a proven way to make it easy to just define your own blobs with *either* standard or vendor specific structures without worry of ID collisions between vendors.
True. I think the pain is overstated, though. In this case I think we actually want something that can be shared between projects and orgs, so some amount of coordination could be considered a benefit. It could just be a github pull request. I find the UUID unfriendly and not just to code size and eyesight! Trying to discover what GUIDs mean or are valid is quite tricky. E.g. see this code:
#define FSP_HOB_RESOURCE_OWNER_TSEG_GUID \
EFI_GUID(0xd038747c, 0xd00c, 0x4980, \
0xb3, 0x19, 0x49, 0x01, 0x99, 0xa4, 0x7d, 0x55)
(etc.)
static struct guid_name {
efi_guid_t guid;
const char *name;
} guid_name[] = {
{ FSP_HOB_RESOURCE_OWNER_TSEG_GUID, "TSEG" },
{ FSP_HOB_RESOURCE_OWNER_FSP_GUID, "FSP" },
{ FSP_HOB_RESOURCE_OWNER_SMM_PEI_SMRAM_GUID, "SMM PEI SMRAM" },
{ FSP_NON_VOLATILE_STORAGE_HOB_GUID, "NVS" },
{ FSP_VARIABLE_NV_DATA_HOB_GUID, "Variable NVS" },
{ FSP_GRAPHICS_INFO_HOB_GUID, "Graphics info" },
{ FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID1, "PCD database ea" },
{ FSP_HOB_RESOURCE_OWNER_PCD_DATABASE_GUID2, "PCD database 9b" },
(never figured out what those two are)
{ FSP_HOB_RESOURCE_OWNER_PEIM_DXE_GUID, "PEIM Init DXE" },
{ FSP_HOB_RESOURCE_OWNER_ALLOC_STACK_GUID, "Alloc stack" },
{ FSP_HOB_RESOURCE_OWNER_SMBIOS_MEMORY_GUID, "SMBIOS memory" },
{ {}, "zero-guid" },
{}
};
static const char *guid_to_name(const efi_guid_t *guid)
{
struct guid_name *entry;
for (entry = guid_name; entry->name; entry++) {
if (!guidcmp(guid, &entry->guid))
return entry->name;
}
return NULL;
}
Believe it or not it took a fair bit of effort to find just that small list, with nearly every one in a separate doc, from memory.
We can probably debate whether there is any value in GUID/UUID or not during the call… but again, boblist seems like a reasonable starting point as an alternative to HOB.
Indeed. There is certainly value in both approaches.
Regards,
Simon
Thanks,
--Harb
From: François Ozog <francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org>>
Sent: Tuesday, March 23, 2021 10:00 AM
To: François Ozog <francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org>>; Ron Minnich <rminnich(a)google.com<mailto:rminnich@google.com>>; Paul Isaac's <paul.isaacs(a)linaro.org<mailto:paul.isaacs@linaro.org>>
Cc: Simon Glass <sjg(a)chromium.org<mailto:sjg@chromium.org>>; Harb Abdulhamid OS <abdulhamid(a)os.amperecomputing.com<mailto:abdulhamid@os.amperecomputing.com>>; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org<mailto:boot-architecture@lists.linaro.org>>; tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
Subject: Re: [TF-A] Proposal: TF-A to adopt hand-off blocks (HOBs) for information passing between boot stages
+Ron Minnich<mailto:rminnich@google.com> +Paul Isaac's<mailto:paul.isaacs@linaro.org>
Adding Ron and Paul because I think this interface should be also benefiting LinuxBoot efforts.
On Tue, 23 Mar 2021 at 11:17, François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
Hi,
I propose we cover the topic at the next Trusted Substrate<https://collaborate.linaro.org/display/TS/Trusted+Substrate+Home> zoom call<https://linaro-org.zoom.us/j/94563644892> on April 8th 4pm CET.
The agenda:
ABI between non-secure firmware and the rest of firmware (EL3, S-EL1, S-EL2, SCP) to adapt hardware description to some runtime conditions.
runtime conditions here relates to DRAM size and topology detection, secure DRAM memory carvings, PSCI and SCMI interface publishing.
For additional background on existing metadata: UEFI Platform Initialization Specification Version 1.7<https://uefi.org/sites/default/files/resources/PI_Spec_1_7_final_Jan_2019.p…>, 5.5 Resource Descriptor HOB
Out of the ResourceType we care about is EFI_RESOURCE_SYSTEM_MEMORY.
This HOB lacks memory NUMA attachment or something that could be related to fill SRAT table for ACPI or relevant DT proximity domains.
HOB is not consistent accros platforms: some platforms (Arm) lists memory from the booting NUMA node, other platforms (x86) lists all memory from all NUMA nodes. (At least this is the case on the two platforms I tested).
There are two proposals to use memory structures from SPL/BLx up to the handover function (as defined in the Device Tree technical report<https://docs.google.com/document/d/1CLkhLRaz_zcCq44DLGmPZQFPbYHOC6nzPowaL0X…>) which can be U-boot (BL33 or just U-Boot in case of SPL/U-Boot scheme) or EDK2.
I would propose we also discuss possibility of FF-A interface to actually query information or request actions to be done (this is a model actually used in some SoCs with proprietary SMC calls).
Requirements (to be validated):
- ACPI and DT hardware descriptions.
- agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2)
- agnostic to boot framework (SPL/U-Boot, TF-A/U-Boot, TF-A/EDK2, TF-A/LinuxBoot)
- at least allows complete DRAM description and "persistent" usage (reserved areas for secure world or other usages)
- support secure world device assignment
Cheers
FF
On Mon, 22 Mar 2021 at 19:56, Simon Glass <sjg(a)chromium.org<mailto:sjg@chromium.org>> wrote:
Hi,
Can I suggest using bloblist for this instead? It is lightweight,
easier to parse, doesn't have GUIDs and is already used within U-Boot
for passing info between SPL/U-Boot, etc.
Docs here: https://github.com/u-boot/u-boot/blob/master/doc/README.bloblist
Header file describes the format:
https://github.com/u-boot/u-boot/blob/master/include/bloblist.h
Full set of unit tests:
https://github.com/u-boot/u-boot/blob/master/test/bloblist.c
Regards,
Simon
On Mon, 22 Mar 2021 at 23:58, François Ozog <francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org>> wrote:
>
> +Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org<mailto:boot-architecture@lists.linaro.org>>
>
> standardization is very much welcomed here and need to accommodate a very
> diverse set of situations.
> For example, TEE OS may need to pass memory reservations to BL33 or
> "capture" a device for the secure world.
>
> I have observed a number of architectures:
> 1) pass information from BLx to BLy in the form of a specific object
> 2) BLx called by BLy by a platform specific SMC to get information
> 3) BLx called by BLy by a platform specific SMC to perform Device Tree
> fixups
>
> I also imagined a standardized "broadcast" FF-A call so that any firmware
> element can either provide information or "do something".
>
> My understanding of your proposal is about standardizing on architecture 1)
> with the HOB format.
>
> The advantage of the HOB is simplicity but it may be difficult to implement
> schemes such as pruning a DT because device assignment in the secure world.
>
> In any case, it looks feasible to have TF-A and OP-TEE complement the list
> of HOBs to pass information downstream (the bootflow).
>
> It would be good to start with building the comprehensive list of
> information that need to be conveyed between firmware elements:
>
> information. | authoritative entity | reporting entity | information
> exchanged:
> dram | TFA | TFA |
> <format to be detailed, NUMA topology to build the SRAT table or DT
> equivalent?>
> PSCI | SCP | TFA? |
> SCMI | SCP or TEE-OS | TFA? TEE-OS?|
> secure SRAM | TFA. | TFA. |
> secure DRAM | TFA? TEE-OS? | TFA? TEE-OS? |
> other? | |
> |
>
> Cheers
>
> FF
>
>
> On Mon, 22 Mar 2021 at 09:34, Harb Abdulhamid OS via TF-A <
> tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
>
> > Hello Folks,
> >
> >
> >
> > I'm emailing to start an open discussion about the adoption of a concept
> > known as "hand-off blocks" or HOB to become a part of the TF-A Firmware
> > Framework Architecture (FFA). This is something that is a pretty major
> > pain point when it comes to the adoption of TF-A in ARM Server SoC’s
> > designed to enable a broad range of highly configurable datacenter
> > platforms.
> >
> >
> >
> >
> >
> > What is a HOB (Background)?
> >
> > ---------------------------
> >
> > UEFI PI spec describes a particular definition for how HOB may be used for
> > transitioning between the PEI and DXE boot phases, which is a good
> > reference point for this discussion, but not necessarily the exact solution
> > appropriate for TF-A.
> >
> >
> >
> > A HOB is simply a dynamically generated data structure passed in between
> > two boot phases. This is information that was obtained through discovery
> > and needs to be passed forward to the next boot phase *once*, with no API
> > needed to call back (e.g. no call back into previous firmware phase is
> > needed to fetch this information at run-time - it is simply passed one time
> > during boot).
> >
> >
> >
> > There may be one or more HOBs passed in between boot phases. If there are
> > more than one HOB that needs to be passed, this can be in a form of a "HOB
> > table", which (for example) could be a UUID indexed array of pointers to
> > HOB structures, used to locate a HOB of interest (based on UUID). In such
> > cases, instead of passing a single HOB, the boot phases may rely on passing
> > the pointer to the HOB table.
> >
> >
> >
> > This has been extremely useful concept to employ on highly configurable
> > systems that must rely on flexible discovery mechanisms to initialize and
> > boot the system. This is especially helpful when you have multiple
> >
> >
> >
> >
> >
> > Why do we need HOBs in TF-A?:
> >
> > -----------------------------
> >
> > It is desirable that EL3 firmware (e.g. TF-A) built for ARM Server SoC in
> > a way that is SoC specific *but* platform agnostic. This means that a
> > single ARM SoC that a SiP may deliver to customers may provide a single
> > TF-A binary (e.g. BL1, BL2, BL31) that could be used to support a broad
> > range of platform designs and configurations in order to boot a platform
> > specific firmware (e.g. BL33 and possibly even BL32 code). In order to
> > achieve this, the platform configuration must be *discovered* instead of
> > statically compiled as it is today in TF-A via device tree based
> > enumeration. The mechanisms of discovery may differ broadly depending on
> > the relevant industry standard, or in some cases may have rely on SiP
> > specific discovery flows.
> >
> >
> >
> > For example: On server systems that support a broad range DIMM memory
> > population/topologies, all the necessary information required to boot is
> > fully discovered via standard JEDEC Serial Presence Detect (SPD) over an
> > I2C bus. Leveraging the SPD bus, may platform variants could be supported
> > with a single TF-A binary. Not only is this information required to
> > initialize memory in early boot phases (e.g. BL2), the subsequent boot
> > phases will also need this SPD info to construct a system physical address
> > map and properly initialize the MMU based on the memory present, and where
> > the memory may be present. Subsequent boot phases (e.g. BL33 / UEFI) may
> > need to generate standard firmware tables to the operating systems, such as
> > SMBIOS tables describing DIMM topology and various ACPI tables (e.g. SLIT,
> > SRAT, even NFIT if NVDIMM's are present).
> >
> >
> >
> > In short, it all starts with a standardized or vendor specific discovery
> > flow in an early boot stage (e.g. BL1/BL2), followed by the passing of
> > information to the next boot stages (e.g. BL31/BL32/BL33).
> >
> >
> >
> > Today, every HOB may be a vendor specific structure, but in the future
> > there may be benefit of defining standard HOBs. This may be useful for
> > memory discovery, passing the system physical address map, enabling TPM
> > measured boot, and potentially many other common HOB use-cases.
> >
> >
> >
> > It would be extremely beneficial to the datacenter market segment if the
> > TF-A community would adopt this concept of information passing between all
> > boot phases as opposed to rely solely on device tree enumeration. This is
> > not intended to replace device tree, rather intended as an alternative way
> > to describe the info that must be discovered and dynamically generated.
> >
> >
> >
> >
> >
> > Conclusion:
> >
> > -----------
> >
> > We are proposing that the TF-A community begin pursuing the adoption of
> > HOBs as a mechanism used for information exchange between each boot stage
> > (e.g. BL1->BL2, BL2->BL31, BL31->BL32, and BL31->BL33)? Longer term we
> > want to explore standardizing some HOB structures for the BL33 phase (e.g.
> > UEFI HOB structures), but initially would like to agree on this being a
> > useful mechanism used to pass information between each boot stage.
> >
> >
> >
> > Thanks,
> >
> > --Harb
> >
> >
> >
> >
> >
> >
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >
>
>
> --
> François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
> T: +33.67221.6485
> francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org> | Skype: ffozog
> _______________________________________________
> boot-architecture mailing list
> boot-architecture(a)lists.linaro.org<mailto:boot-architecture@lists.linaro.org>
> https://lists.linaro.org/mailman/listinfo/boot-architecture
--
[https://drive.google.com/a/linaro.org/uc?id=0BxTAygkus3RgQVhuNHMwUi1mYWc&ex…]
François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
T: +33.67221.6485
francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org> | Skype: ffozog
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
[https://drive.google.com/a/linaro.org/uc?id=0BxTAygkus3RgQVhuNHMwUi1mYWc&ex…]
François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
T: +33.67221.6485
francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org> | Skype: ffozog
--
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https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi all,
I'm currently debugging sporadic lockups in TF-A when calling the system
reset hook of OP-TEE: opteed_system_reset() gets stuck on
opteed_synchronous_sp_entry(), and the thread_system_reset_handler of
OP-TEE is not invoked (I left a debug output on the OP-TEE side).
Platform is k3, target hardware our IOT2050 device. I was using today's
master of TF-A and OP-TEE, but also older versions of both.
What could cause this? I would assume that TF-A and OP-TEE are protected
against overwriting of the non-secure world and we would see exceptions
in case some reservation is not properly set, possibly misleading Linux.
Jan
--
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux
Hi,
This is to notify that we are planning to target the Trusted Firmware-A 2.5 release during the second week of May 2021 as part of the regular ~6-month cadence. The aim is to consolidate all TF-A work since the 2.4 release. As part of this, a release candidate tag will be created and release activities will commence after the 30th of April. Essentially we will not merge any major enhancements from this date until the release is made. Please ensure any Gerrit Patch Reviews desired to make the 2.5 release are submitted in good time to be complete by last week of Apr 2021. Any major enhancement Gerrit Patch Reviews still open after that date will not be merged until after the release.
Hi Everyone,
If you get an invite to join the trusted-firmware-ci organization in Github it’s to allow all the project contributors seeded from the TF-A maintainers file (maintainers and code owners) to have the privileges to be able to perform Jenkin job rebuilds from the OpenCI Jenkins pages for the TF-A project. All the TF-A project maintainers will have the admin ability to add new people.
Thanks
Joanna
Hi All,
The next TF-A Tech Forum is scheduled for Thu 8th April 2021 16:00 – 17:00 (BST).
Agenda:
* TF-A OpenCI Update and Q&A
* Lead by Joanna Farley
* Following the posting in late March https://lists.trustedfirmware.org/pipermail/tf-a/2021-March/001045.html announcing the availability of the OpenCI this session is an update on the status and a run through of what’s available in the OpenCI to project contributors. I will have representatives from the OpenCI infrastructure team from Linaro along side TF-A project members familiar with the TF-A CI testing on the call to help answer any questions.
* Attached is an early draft of the OpenCI documentation with Version 1.0 expected soon.
Thanks
Joanna
raghu.ncstate(a)icloud.com:
> Are you pushing ssh://<username>@review.trustedfirmware.org:29418/TF-A/trusted-firmware-a HEAD:refs/for/integration?
> Note that 29418 port. That tripped me up initially. It is not clear from your earlier emails where you cloned from(review.trustedfirmware.org or git.trustedfirmware.org).
[α] links to [β] which recommends
# git clone "https://review.trustedfirmware.org/TF-A/trusted-firmware-a"
I had an existing repository (most contributors probably do) and used
'git add remote' and 'git fetch' instead.
[α] recommends
# git push <remote-name> HEAD:refs/for/integration%<topic-branch>
As expected, the host requires a password.
# git push ssh://<user>@review.trustedfirmware.org:29418/TF-A/trusted-firmware-a HEAD:refs/for/integration?
-> fatal: invalid refspec 'HEAD:refs/for/integration?'
Anyhow, the host would require an SSH key.
[α] https://developer.trustedfirmware.org/w/tf_a/gerrit-getting-started/
[β] https://review.trustedfirmware.org/admin/repos/TF-A%2Ftrusted-firmware-a
Hi
Trusted Firmware M recently introduced protection against glitching at
key decision points:
https://github.com/mcu-tools/mcuboot/pull/776
To me this is a key mitigation element for companies that target PSA
level 3 compliance which means hardware attacks resilience.
I believe similar techniques need to be used in different projects
involved in Linux secure booting (TF-A, OP-TEE, U-Boot, Linux kernel).
Are there any efforts planned around this ?
Is it feasible to have a "library" that could be integrated in
different projects?
Cheers
FF
To += op-tee(a)lists.trustedfirmware.org<mailto:op-tee@lists.trustedfirmware.org>
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of François Ozog via TF-A
Sent: 26 March 2021 19:08
To: Heinrich Schuchardt <xypron.glpk(a)gmx.de>
Cc: tf-a(a)lists.trustedfirmware.org; Boot Architecture Mailman List <boot-architecture(a)lists.linaro.org>; Ilias Apalodimas <ilias.apalodimas(a)linaro.org>
Subject: Re: [TF-A] Firmware FuSa workshop
Le ven. 26 mars 2021 à 18:42, Heinrich Schuchardt <xypron.glpk(a)gmx.de<mailto:xypron.glpk@gmx.de>> a écrit :
On 26.03.21 16:05, François Ozog wrote:
> Hi,
>
>
> Linaro is conducting an opportunity assessment to make OP-TEE ready for
> functional safety sensitive environments. The goal is to present a plan to
> Linaro members by the end of July 2021.
>
> The scope of the research is somewhat bigger because we can’t think of
> OP-TEE without thinking of Trusted Firmware and Hafnium. The plan will
> though not address those (unless we recognize we have to). We don’t think
> U-Boot shall be part of the picture but we are welcoming contradictory
> points of views.
Hello François,
Some boards boot via SPL->TF-A->U-Boot. Here U-Boot's SPL is relevant
for OP-TEE's security.
U-Boot can save variables via OP-TEE (implemented by Ilias). In this
case OP-TEE has an implication on secure boot.
I fully understand that these scenarios are not in the focus of the
workshop.
it may if companies have this particular flow in mind for safety certification. Our goal is not to make all boot flows safety ready but to identify which ones we need to consider. And the workshop may help in this identification.
Best regards
Heinrich
>
> We are organizing a 2 hours workshop on April 15th 9am CET to mostly hear
> about use cases and ideas about Long Term Support requirements . We will
> present the state of the research.
>
> The first use case is booting a safety certified type-1 hypervisor (open
> source or commercial is irrelevant).
>
> But we know there are many more: please be ready to contribute.
>
> We think of more radical use cases: a safety payload is actually loaded as
> a Secure Partition on top of Hafnium with OP-TEE or Zephyr used as a device
> backends. In other words, Trust Zone hosts both safety and security worlds
> , EL3 being the « software root of trust » pivot world. In those cases,
> some cores never go out of secure state…
>
>
> Agenda (to be refined)
>
> -
>
> Vision
> -
>
> State of the research
> <https://docs.google.com/presentation/u/0/d/1jWqu39gCF-5XzbFkodXsiVNJJLUN88B…>
> -
>
> Use cases discussion
> -
>
> What is the right scope?
> -
>
> “Who do what” discussion (LTS, archiving...)
> -
>
> Safety personnel (Linaro and contractors) discussion
> -
>
> Other considerations from participants?
> -
>
> Community organizations and funding?
> -
>
> Closing and next steps
>
>
> Should you want to participate and have not yet received an invite, please
> contact me directly.
>
> Cordially,
>
> François-Frédéric
>
> PS: Please reach out should you want another date with a time compatible
> with more time zones. This alternate date is not guaranteed though.
>
>
--
[https://drive.google.com/a/linaro.org/uc?id=0BxTAygkus3RgQVhuNHMwUi1mYWc&ex…]
François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
T: +33.67221.6485
francois.ozog(a)linaro.org<mailto:francois.ozog@linaro.org> | Skype: ffozog
Hi Everyone,
I wanted to give an update on the availability of the TF-A OpenCI. Recognised projects contributors can now invoke the OpenCI on patches they submit or patches they review through Gerrit and so view results and fix any issues identified without an Arm reviewer having to intercede and start the Open CI for them.
This is achieved in Gerrit patches (https://review.trustedfirmware.org/p/TF-A/trusted-firmware-a/+/dashboard/si…) by setting the Allow-CI label with +1 or +2 where +1 is a light level of testing and +2 includes additional tests on top of the +1 tests. Results are linked to in the Gerrit patch comments.
Recognised projects contributors is currently seeded as everybody listed in https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/docs/about… including all maintainers and code-owners. The intent going forward is to include others when vouched for by other recognised projects contributors. In this way we hope to be open to all project contributors to have access to the OpenCI while providing some protection to the OpenCI back end resources.
The plan is to have another TF-A Tech-Forum session on the OpenCI on 8th April 2021 where more of the details of the OpenCI can be shared, discussed and questions can be taken.
For now please experiment with the OpenCI through your patch submissions or reviews. Please be aware this is a shared resource and use when appropriate during the patch review and be tolerant if its not quite perfect yet. Please rest assured the existing Legacy CI is still available during this transition to the OpenCI where needed to help ensure patches are adequately tested to maintain repository quality levels.
I’ll like to say a big thanks to the Linaro team working in the background to provide the OpenCI service to the TF-A project.
Cheers
Joanna
Hi,
Linaro is conducting an opportunity assessment to make OP-TEE ready for
functional safety sensitive environments. The goal is to present a plan to
Linaro members by the end of July 2021.
The scope of the research is somewhat bigger because we can’t think of
OP-TEE without thinking of Trusted Firmware and Hafnium. The plan will
though not address those (unless we recognize we have to). We don’t think
U-Boot shall be part of the picture but we are welcoming contradictory
points of views.
We are organizing a 2 hours workshop on April 15th 9am CET to mostly hear
about use cases and ideas about Long Term Support requirements . We will
present the state of the research.
The first use case is booting a safety certified type-1 hypervisor (open
source or commercial is irrelevant).
But we know there are many more: please be ready to contribute.
We think of more radical use cases: a safety payload is actually loaded as
a Secure Partition on top of Hafnium with OP-TEE or Zephyr used as a device
backends. In other words, Trust Zone hosts both safety and security worlds
, EL3 being the « software root of trust » pivot world. In those cases,
some cores never go out of secure state…
Agenda (to be refined)
-
Vision
-
State of the research
<https://docs.google.com/presentation/u/0/d/1jWqu39gCF-5XzbFkodXsiVNJJLUN88B…>
-
Use cases discussion
-
What is the right scope?
-
“Who do what” discussion (LTS, archiving...)
-
Safety personnel (Linaro and contractors) discussion
-
Other considerations from participants?
-
Community organizations and funding?
-
Closing and next steps
Should you want to participate and have not yet received an invite, please
contact me directly.
Cordially,
François-Frédéric
PS: Please reach out should you want another date with a time compatible
with more time zones. This alternate date is not guaranteed though.
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
Hi,
Recently the same fault injection protection code what is used in MCUboot was added to TF-M project.
https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/7468
It is a library which can be reused in any project to harden the critical call path and condition checks, which are crucial from device security point of view.
BR,
Tamas Ban
Hi François,
The TF-A team members have thought about trying to explore the use of more mitigations for Side Channel attacks along the lines of "Canary In the Coalmine" type techniques to as you say build additional resilience and as you can expect the techniques used by our peer TF-M project are one we would like to explore. I would not say this is a plan as such but definitely something already listed on our backlog. As to if the TF-M code can be reused that would need to be explored more.
Cheers
Joanna
On 26/03/2021, 14:12, "TF-A on behalf of François Ozog via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi
Trusted Firmware M recently introduced protection against glitching at
key decision points:
https://github.com/mcu-tools/mcuboot/pull/776
To me this is a key mitigation element for companies that target PSA
level 3 compliance which means hardware attacks resilience.
I believe similar techniques need to be used in different projects
involved in Linux secure booting (TF-A, OP-TEE, U-Boot, Linux kernel).
Are there any efforts planned around this ?
Is it feasible to have a "library" that could be integrated in
different projects?
Cheers
FF
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Sandeep,
I just noticed that your PR is abandoned. Will you resend your PR?
Thanks,
Peng.
________________________________
From: OP-TEE <op-tee-bounces(a)lists.trustedfirmware.org> on behalf of Peng Fan via OP-TEE <op-tee(a)lists.trustedfirmware.org>
Sent: Tuesday, March 23, 2021 10:14 AM
To: Sandeep Tripathy <sandeep.tripathy(a)broadcom.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; op-tee(a)lists.trustedfirmware.org <op-tee(a)lists.trustedfirmware.org>
Subject: RE: [TF-A] EHF + OPTEE on ARM64
Hi Sandeep
> Subject: Re: [TF-A] EHF + OPTEE on ARM64
>
> Hi Peng,
>
> 1-Asynchronous preemption of SP:
> The long route is to make changes in the dispatcher and the
> corresponding SPD implementation to have synchronous preemption.
> ie: OP-TEE dispatcher will implement a G1NS (fiq) handler and invoke
> an entry of OP-TEE synchronously. OP-TEE will save the thread context
> and return.
> I did some POC but the complexity and effort to generalise was not
> justified by our requirement at that point especially envisioning the
> movement to SPMD in future.
>
> 2-Synchronous preemption of SP:
> ref:
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Freview.tr…
>
> I used this approach instead to unblock OP-TEE work alongside EHF.
> This serves the purpose without changing the routing model with a
> limitation that non yielding/fast SMC can
> not be preempted. And ofcourse OP-TEE can mask G0 interrupt in
> anycase. But I think this is sufficient for your purpose.
>
> Please feedback if the above patch works for you.
I was trying using #ifndef SPD_opteed to wrap the secure stuff. Thanks
for your patch. I test on i.MX8MM-EVK, it works well.
Thanks,
Peng.
>
> Thanks
> Sandeep
>
> On Mon, Mar 22, 2021 at 2:43 PM Peng Fan via TF-A
> <tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi Achin,
> >
> >
> >
> > We are using SDEI for Jailhouse hypervisor to minimize interrupt latency,
> however we also wanna use OP-TEE when SDEI enabled.
> >
> >
> >
> > So I wanna how to make both work together.
> >
> >
> >
> > Thanks,
> >
> > Peng.
> >
> >
> >
> > From: Achin Gupta [mailto:Achin.Gupta@arm.com]
> > Sent: 2021年3月17日 17:59
> > To: Peng Fan <peng.fan(a)nxp.com>; Jens Wiklander
> <jens.wiklander(a)linaro.org>
> > Cc: op-tee(a)lists.trustedfirmware.org; tf-a(a)lists.trustedfirmware.org
> > Subject: Re: EHF + OPTEE on ARM64
> >
> >
> >
> > Hi Peng,
> >
> >
> >
> > +TF-A folk.
> >
> >
> >
> > My 0.02$.
> >
> >
> >
> > What is the problem you are trying to solve? Why do you need to run
> OP-TEE and EHF together? EHF was originally written to support a S-EL0 SP
> that is managed directly by TF-A in EL3 (TF-A folk can chime in).
> >
> >
> >
> > The SP could perform RAS error handling for which it needs the EHF. The EHF
> triages asynchronous exceptions and hands RAS errors to the SP for further
> handling.
> >
> >
> >
> > This is just one use case but there is no Trusted OS in these configurations.
> >
> >
> >
> > So, it would help to understand the requirement.
> >
> >
> >
> > cheers,
> >
> > Achin
> >
> >
> >
> > ________________________________
> >
> > From: OP-TEE <op-tee-bounces(a)lists.trustedfirmware.org> on behalf of
> Jens Wiklander via OP-TEE <op-tee(a)lists.trustedfirmware.org>
> > Sent: 17 March 2021 09:23
> > To: Peng Fan <peng.fan(a)nxp.com>
> > Cc: op-tee(a)lists.trustedfirmware.org <op-tee(a)lists.trustedfirmware.org>
> > Subject: Re: EHF + OPTEE on ARM64
> >
> >
> >
> > On Wed, Mar 17, 2021 at 9:43 AM Peng Fan <peng.fan(a)nxp.com> wrote:
> > >
> > > > Subject: Re: EHF + OPTEE on ARM64
> > > >
> > > > On Wed, Mar 17, 2021 at 9:02 AM Peng Fan <peng.fan(a)nxp.com>
> wrote:
> > > > >
> > > > > > Subject: Re: EHF + OPTEE on ARM64
> > > > > >
> > > > > > On Wed, Mar 17, 2021 at 8:41 AM Peng Fan <peng.fan(a)nxp.com>
> wrote:
> > > > > > >
> > > > > > > > Subject: Re: EHF + OPTEE on ARM64
> > > > > > > >
> > > > > > > > On Tue, Mar 16, 2021 at 11:08 AM Peng Fan
> <peng.fan(a)nxp.com>
> > > > wrote:
> > > > > > > > >
> > > > > > > > > Hi,
> > > > > > > > >
> > > > > > > > > In bl31/ehf.c, there are following two lines, per my
> > > > > > > > > understanding, when cpu is in secure world, the non-secure
> > > > > > > > > interrupt as FIQ(GICv3) will be directly catched by EL3, not
> S-EL1
> > > > > > > > > /* Route EL3 interrupts when in Secure and
> Non-secure.
> > > > */
> > > > > > > > > set_interrupt_rm_flag(flags, NON_SECURE);
> > > > > > > > > set_interrupt_rm_flag(flags, SECURE);
> > > > > > > > >
> > > > > > > > > So this will conflict with OP-TEE, because OP-TEE needs catch
> > > > > > > > > NS-interrupt as FIQ in S-EL1 world.
> > > > > > > >
> > > > > > > > In the case of GICv3, OP-TEE is configured to receive the
> > > > > > > > non-secure interrupts as FIQ and secure interrupts as IRQ. See
> > > > CFG_ARM_GICV3.
> > > > > > >
> > > > > > > But EHF needs NS-interrupt FIQ be catched by EL3 if I understand
> > > > > > > correct, per " set_interrupt_rm_flag(flags, SECURE);"
> > > > > > >
> > > > > > > So currently EHF could not work together with OP-TEE, right?
> > > > > >
> > > > > > To be honest, I'm not completely sure what EHF does. From OP-TEE
> > > > > > point of view we expect to receive the non-secure interrupts as a
> > > > > > way of doing a controlled exit. This allows OP-TEE to resume
> > > > > > execution with a different core on re-entry. If EL3 takes the
> > > > > > non-secure interrupts directly it will have to make sure to only
> re-enter
> > > > OP-TEE on this core as a return from exception.
> > > > >
> > > > > Is this easy to be achieved?
> > > >
> > > > I don't know, it depends on what you intend to do with this non-secure
> > > > interrupt. If it's handled at EL3 and then there's a return from exception
> back
> > > > to S-EL1 there's likely no harm done. But if there's a world switch
> involved
> > > > there might be trouble, OP-TEE might not be in a suitable state for a
> world
> > > > switch.
> > > >
> > > > >
> > > > > Or by using opteed_sel1_interrupt_handler, could we have similar
> > > > > behavior to allow the other core resume execution?
> > > >
> > > > Only OP-TEE itself can make a controlled exit as there's an internal state
> to
> > > > maintain. Currently that's signalled with a non-secure interrupt.
> > >
> > >
> > > Per EHF,
> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftrustedfi…
> andling.html?highlight=Exception%20Handling%20Framework
> > > On GICv3 systems, when executing in S-EL1, pending Non-secure
> interrupts of
> > > sufficient priority are signalled as FIQs, and therefore will be routed to
> EL3.
> > > As a result, S-EL1 software cannot expect to handle Non-secure interrupts
> at S-EL1.
> > > Essentially, this deprecates the routing mode described as CSS=0, TEL3=0.
> > >
> > > In order for S-EL1 software to handle Non-secure interrupts while having
> EHF enabled,
> > > the dispatcher must adopt a model where Non-secure interrupts are
> received at EL3,
> > > but are then synchronously handled over to S-EL1.
> > >
> > > The issue to me here how to synchronously handled over to S-EL1 and not
> break optee.
> >
> > I understand. OP-TEE is masking interrupts in some critical sections,
> > while in such a state OP-TEE cannot handle any asynchronous interrupt.
> > Temporarily masking interrupts is normally a quick operation so we do
> > it in quite a few places.
> > So the crux of the problem is to make sure that OP-TEE is in a state
> > where it can make a controlled exit. I don't have any good ideas for
> > this right now.
> >
> > Cheers,
> > Jens
> >
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.tru…