Hi,
Can someone explain to me why it is easier to implement a secure TrustZone
environment with secure boot and storage and PSA certificate in cortex-M
than in cortex-A?
Who better implements a safe environment: cortex-M or cortex-A? Why?
Thanks.
Please revert the removal of RSA PKCS#1 v1.5 support from cert_tool:
https://github.com/ARM-software/arm-trusted-firmware/commit/6a415a508ea6ace…
We have products shipping with such support. I think this problem came
up before when somebody tried removing such support.
They still need to run with the latest yocto codebase.
Regards,
Scott
Hi Varun,
It can be a challenge to keep on top of the reviews and we are aware of the backlog increase after the end of year break and trying different approaches to get reviews completed.
Any suggestions on process improvements from the developer community at large are welcome.
Cheers
Joanna
On 16/01/2020, 17:34, "TF-A on behalf of Varun Wadekar via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hello,
We (NVIDIA) frequently post changes on the TF-A gerrit dashboard and wait for the maintainers to gradually get to them. This is very time consuming and non-deterministic.
Curious to know if other developers face the same problems or are we missing something when asking for reviews? If most of us face the same problems, then we should try to formulate a process to reduce the latency.
Thoughts?
-Varun
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Hello,
We (NVIDIA) frequently post changes on the TF-A gerrit dashboard and wait for the maintainers to gradually get to them. This is very time consuming and non-deterministic.
Curious to know if other developers face the same problems or are we missing something when asking for reviews? If most of us face the same problems, then we should try to formulate a process to reduce the latency.
Thoughts?
-Varun
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This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
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On 13/12/2019 22:04, Julius Werner via TF-A wrote:
> On Fri, Dec 13, 2019 at 6:20 AM Joanna Farley <Joanna.Farley(a)arm.com> wrote:
>> On the subject of DebugFS's purpose it was envisages and is today as Sandrine describes as a debug build only capability. Saying that though there has been some early thoughts that it could evolve into a Secure Debug feature where this type of capability or something like it is always on requiring debug certificates for authenticated access. This is something very much for a possible future evolution and is not in the patches available today. We would welcome any thoughts on such an evolution in this space.
>
> I guess this gets into a bit of a philosophy discussion and becomes a
> matter of opinion, so there's probably no one right answer.
> Personally, adding authentication on top of this doesn't really
> resolve my concerns and adds yet more on top. I'm a strong proponent
> of the concept of a minimal Trusted Computing Base, i.e. keeping the
> amount of code executing at the highest privilege level as small and
> low-complexity as possible. Any code can have bugs, so the idea is
> that the more complicated the code you run in EL3 is (and the more
> complicated APIs it exposes), the more likely it becomes that you
> accidentally have an exploitable vulnerability in there. Like a p9
> filesystem driver, a certificate-based authentication system
> (especially if it's based on x509/ASN.1 which are notoriously hard to
> implement safely) is a pretty complex piece of code with a pretty
> large attack surface that I'd rather not have in my EL3 firmware if I
> can avoid it. I understand that for certain use cases you may need
> something like this (if you really want a very extensive and
> extensible debugging API that must be restricted to a few
> authenticated actors), but in my use case I really just need the
> ability to trigger one small debugging feature and that feature itself
> doesn't need to be restricted, so a minimal SMC interface would work
> much better for that case.
Hi Julius,
Just to trying to understand, if TF-A were to expose a crash inducing
SMC, this would still be restricted to special builds for your test runs
? This would not make it to production for Chromebook right ?
I agree 9p filesystem is not desirable in a EL3 runtime firmware. We
could enhance it to use a more tight data structure, if there is a
desire in that direction.
If that is the case, leaving aside the 9p filesystem issues, can
DebugFS serve this requirement (we can remove the limitation that it is
restricted to only Debug builds) ?
The intention that DebugFS can prove useful atleast in the
verification/testing space and if there is more we can do to get there,
it would be good to know.
>
>> On 13/12/2019, 13:01, "TF-A on behalf of Sandrine Bailleux via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
>> Going back to the SMC-based solution then, I am not quite convinced
>> SYSTEM_RESET2 is the right interface for intentionally triggering a
>> panic in TF-A. I think the semantics do not quite match. If anything, a
>> firmware crash seems more like a shutdown operation to me rather than a
>> reset (we don't recover from a firmware crash). I am not even sure we
>> should look into the PSCI SMC range, as it's not a power-management
>> operation.
>
> Crash recovery behavior is platform dependent (via
> plat_panic_handler()). On all the platforms we use in Chrome OS we
> have that implemented as a system reboot. I think for most systems
> (whether it's a Chromebook, a server or some embedded device) that's
> probably what you want for random runtime crashes (and least in a
> production environment), but I agree that TF doesn't enforce any
> standard behavior so it's hard to clearly match it to one or the other
> SMC.
>
>> So it sounds like it's not the first time that you hit this issue, is
>> it? Do you have any other example of Normal World OS feature you would
>> have liked to expose through a generic SMC interface? I am wondering
>> whether this could help choosing the right SMC range, if we can identify
>> some common criteria among a set of such features.
>
> No, it's the first time I've really run into this. But I think we
> might quickly come up with more uses for a "non-secure OS" SMC range
> if we had one. We often see roughly the same SMC again on different
> platforms, because fundamentally they usually need to do the same
> kinds of things -- for example, most platforms have some kind of DDR
> frequency scaling which always needs part of it implemented in EL3, so
> they all need some kind of SMC to switch to a new DDR frequency. Many
> also need some kind of "write value to secure register" SMC that just
> allows the non-secure OS to write a few whitelisted registers that are
> only accessible in EL3 for some reason. If we could standardize these
> interfaces in a non-vendor-specific SMC range, we might be able to
> reduce some code duplication both on the TF and the Linux side.
>
> I guess none of these things are really Linux-specific, now that I
> think of it. So really, I guess the problem is that it would be great
> to have a range of "generic" SMC IDs that can be easily and
> unbureaucratically allocated to try out new features, without having
> to ask Arm to write a big specification document about it every time.
> It's sort of a development velocity issue.
>
We have utilized the ARM SiP range for some "generic" purposes in the
past (see PMF and the execution state switch SMCs). This could be
direction for the some of use-cases. But if the SMCs are meant to be
truly generic and to be relied on for use by generic normal world
software components, it would need to be properly specified I would think.
For dynamically modifying some EL3 registers, it would be good to get
these requirements out. Perhaps there is scope for architecting some of
them as an ARM specification. If not, we could revert to a TF-A standard
if there is enough pull for them (perhaps utilizing the ARM SiP range).
Best Regards
Soby Mathew
Hi
Just to add to this: Given that:
* Your BL31 is nearly 64KB on its own, and
* DDR attacks are more feasible on runtime resident code (e.g. BL31)
Perhaps another more secure solution would be to do DDR init in BL1 or a new transient BL1.5 stage in SRAM. That way you could run BL31 in SRAM, and BL2 and other boot stages in DDR. You would still need to cut down the BL1_RW size though for this to work.
One way to cut down the memory used for page tables is to map all the required memory/devices in larger/fewer address ranges, and align the ranges on block boundaries (i.e. 2MB or 1GB for 4KB translation granules). Although this means mapping in unused address space, which might be less secure, it uses less memory for page tables.
Regards
Dan.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Soby Mathew
> via TF-A
> Sent: 13 January 2020 15:13
> To: Raghupathy Krishnamurthy <raghu.ncstate(a)icloud.com>; "严鸿亮(鸿先)"
> <hongxian.yhl(a)alibaba-inc.com>; tf-a(a)lists.trustedfirmware.org
> Cc: nd <nd(a)arm.com>
> Subject: Re: [TF-A] 回复:回复: MMU Table in ARM Trust-Firmware-A
>
> [Adding back TF-A list]
> Hi Raghu
> Since the same DRAM is partitioned to run both non-secure and secure software,
> it is susceptible to Row Hammer attacks. Also depending on how accessible the
> DRAM interface is, the DDR PHY can be probed for transactions. If the DRAM is
> removable, then it can be deep frozen to retain values and plugged into
> another system to extract contents. Hence the less `secure` comment.
>
> Best Regards
> Soby Mathew
>
> From: Raghupathy Krishnamurthy <raghu.ncstate(a)icloud.com>
> Sent: 13 January 2020 14:36
> To: "严鸿亮(鸿先)" <hongxian.yhl(a)alibaba-inc.com>
> Cc: Soby Mathew <Soby.Mathew(a)arm.com>; Xie, Shaolin <shaolin.xie@alibaba-
> inc.com>; nd <nd(a)arm.com>
> Subject: Re: [TF-A] 回复:回复: MMU Table in ARM Trust-Firmware-A
>
> Hi Soby,
>
> >>It is possible to create a secure carve-out in DDR and execute BL31
> >>from there. It is less `secure` than running from SRAM but it is
> >>acceptable for some market segments depending on the threat model.
>
>
> Can you elaborate on why you say it is less "secure" to run out of DDR?
>
>
> -Raghu
>
> On January 13, 2020 at 4:36 AM, "严鸿亮(鸿先) via TF-A" <tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
> Hi Soby,
>
> Many thanks for your advice. I will try to RUN BL2 as Boot ROM and try to
> reduce the BL31 size. Hope BL2_NOPROGBITS+BL31 can be restricted below 64KB.
> Wish me good luck:).
>
> Best Regards
> Yan Hongliang
>
>
>
>
>
>
>
> ------------------------------------------------------------------
> 发件人:Soby Mathew <Soby.Mathew(a)arm.com<mailto:Soby.Mathew@arm.com>>
> 发送时间:2020年1月13日(星期一) 19:37
> 收件人:严鸿亮(鸿先) <hongxian.yhl(a)alibaba-inc.com<mailto:hongxian.yhl@alibaba-
> inc.com>>; "Xie, Shaolin" <shaolin.xie@alibaba-
> inc.com<mailto:shaolin.xie@alibaba-inc.com>>; tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> <tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
> 抄 送:nd <nd(a)arm.com<mailto:nd@arm.com>>; Ash Wilding
> <Ash.Wilding(a)arm.com<mailto:Ash.Wilding@arm.com>>
> 主 题:RE: 回复:[TF-A] MMU Table in ARM Trust-Firmware-A
>
> Hi Yan,
> OK, sounds good. From your description of the platform, having BL2 as the
> Boot ROM is worth exploring. This way, you avoid the BL1_RW , BL2_PROGBITS
> memory overhead. BL2_NOPROGBITS will need to be in SRAM. See the BL2_AT_EL3
> and BL2_IN_XIP_MEM build flags for details. This depends on BL31 being able
> to fit in the free space available after this is done. One option is using
> the RECLAIM_INIT_CODE option which reclaims BL31 init-only code for runtime
> data but it needs platform specific linker script support. There are other
> ways to reduce the BL31 size, but trading security like
> SEPARATE_CODE_AND_RODATA=0 or trading performance like USE_COHERENT_MEM=0.
> Hope that helps.
> Best Regards
> Soby Mathew
> From: 严鸿亮(鸿先) <hongxian.yhl(a)alibaba-inc.com<mailto:hongxian.yhl@alibaba-
> inc.com>>
> Sent: 11 January 2020 06:04
> To: Soby Mathew <Soby.Mathew(a)arm.com<mailto:Soby.Mathew@arm.com>>; Xie,
> Shaolin <shaolin.xie(a)alibaba-inc.com<mailto:shaolin.xie@alibaba-inc.com>>;
> tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
> Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>; Ash Wilding
> <Ash.Wilding(a)arm.com<mailto:Ash.Wilding@arm.com>>
> Subject: 回复:[TF-A] MMU Table in ARM Trust-Firmware-A Hi Soby, Thanks for
> your replies.
> Currently, out BL2 size is 60KB, BL1_RW is 28KB, BL31_PROGBITS is 48KB,
> BL31_NOPROGBITS is 24KB. For our testchip, we don't have too strictly
> security requirement, so maybe putting BL31 into DDR is a way to save SRAM
> and we don't need to worry about PROGBITS limit between BL31 and BL2.
> For BL1_RW and BL2, there is 40KB used for MMU table. After I disable the MMU
> related code in arm_bl1_plat_arch_setup()/arm_bl2_plat_arch_setup() and also
> disable the build of xlat_table_lib, this 40KB space is saved. If the
> consequence is decreasing performance and losing MMU protection without any
> other functionality problem, then we might try this.
>
> Best Regards
> Yan Hongliang
>
>
>
>
>
>
> ------------------------------------------------------------------
> 发件人:Soby Mathew <Soby.Mathew(a)arm.com<mailto:Soby.Mathew@arm.com>>
> 发送时间:2020年1月10日(星期五) 18:27
> 收件人:"Xie, Shaolin" <shaolin.xie@alibaba-
> inc.com<mailto:shaolin.xie@alibaba-inc.com>>; tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> <tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
> 抄 送:nd <nd(a)arm.com<mailto:nd@arm.com>>; 严鸿亮(鸿先) <hongxian.yhl@alibaba-
> inc.com<mailto:hongxian.yhl@alibaba-inc.com>>; Ash Wilding
> <Ash.Wilding(a)arm.com<mailto:Ash.Wilding@arm.com>>
> 主 题:Re: [TF-A] MMU Table in ARM Trust-Firmware-A
>
> On 10/01/2020 09:05, shaolin.xie via TF-A wrote:
> > Hey all:
> >
> > We are trying to port ARM Trust-Firmware-A to our design, however, we are
> facing serious SRAM size problem.
> >
> > Our target SRAM is 64KB, but the compiled BL2 already taken 60K:
> >
> > After some evaluation, we found that the MMU table take most of the space.
> Our questions are:
> Hi Shaolin,
> There are some options to reduce the memory used for page-tables like using
> non-identity virtual to physical mappings. But given your SRAM size, I
> suspect you may not save enough to fit BL31.
>
> >
> > 1. Can we disable the MMU so we can fit the BL2 into 64KB space?
> > (However, in ARM's porting guide, enable MMU and icache/dcache is
> > mandatory. Refer to chapter 7.3 in
> > https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/por
> > ting-guide.html#introduction
> > <https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/po
> > rting-guide.html#introduction>.)
>
> This is a possibility although not recommended for performance reasons and
> you lose the protection of MMU during BL2 execution. This is not a
> configuration we support an I suspect some changes to BL2 code may be
> required for this.
>
> >
> > 2. In current design, BL31 is run in SRAM. If we enable DDR in BL2 and load
> BL31 image to DDR, is there any potential issue?
> >
> > Thanks in advances,
> >
> >
>
> It is possible to create a secure carve-out in DDR and execute BL31 from
> there. It is less `secure` than running from SRAM but it is acceptable for
> some market segments depending on the threat model.
>
> You target SRAM of 64 KB is on the lower side and fitting both BL2 and
> BL31 in that space could be a challenge.
>
> Could you let us know your BL2 and BL31 size and could you break down the
> size in terms of PROGBITS and NOPROG BITS? The BL31 NOPROG BITS are usually
> overlayed on top of BL2 memory and this will let us know whether fitting both
> in SRAM is even possible. If both cannot fit together in SRAM, there are
> other options you can explore like loading BL31 directly from BootROM or
> using BL2 as an XIP BootROM image.
>
> Best Regards
> Soby Mathew
>
>
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org<mailto:TF-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
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
[Adding back TF-A list]
Hi Raghu
Since the same DRAM is partitioned to run both non-secure and secure software, it is susceptible to Row Hammer attacks. Also depending on how accessible the DRAM interface is, the DDR PHY can be probed for transactions. If the DRAM is removable, then it can be deep frozen to retain values and plugged into another system to extract contents. Hence the less `secure` comment.
Best Regards
Soby Mathew
From: Raghupathy Krishnamurthy <raghu.ncstate(a)icloud.com>
Sent: 13 January 2020 14:36
To: "严鸿亮(鸿先)" <hongxian.yhl(a)alibaba-inc.com>
Cc: Soby Mathew <Soby.Mathew(a)arm.com>; Xie, Shaolin <shaolin.xie(a)alibaba-inc.com>; nd <nd(a)arm.com>
Subject: Re: [TF-A] 回复:回复: MMU Table in ARM Trust-Firmware-A
Hi Soby,
>>It is possible to create a secure carve-out in DDR and execute BL31 from
>>there. It is less `secure` than running from SRAM but it is acceptable
>>for some market segments depending on the threat model.
Can you elaborate on why you say it is less "secure" to run out of DDR?
-Raghu
On January 13, 2020 at 4:36 AM, "严鸿亮(鸿先) via TF-A" <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
Hi Soby,
Many thanks for your advice. I will try to RUN BL2 as Boot ROM and try to reduce the BL31 size. Hope BL2_NOPROGBITS+BL31 can be restricted below 64KB. Wish me good luck:).
Best Regards
Yan Hongliang
------------------------------------------------------------------
发件人:Soby Mathew <Soby.Mathew(a)arm.com<mailto:Soby.Mathew@arm.com>>
发送时间:2020年1月13日(星期一) 19:37
收件人:严鸿亮(鸿先) <hongxian.yhl(a)alibaba-inc.com<mailto:hongxian.yhl@alibaba-inc.com>>; "Xie, Shaolin" <shaolin.xie(a)alibaba-inc.com<mailto:shaolin.xie@alibaba-inc.com>>; tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
抄 送:nd <nd(a)arm.com<mailto:nd@arm.com>>; Ash Wilding <Ash.Wilding(a)arm.com<mailto:Ash.Wilding@arm.com>>
主 题:RE: 回复:[TF-A] MMU Table in ARM Trust-Firmware-A
Hi Yan,
OK, sounds good. From your description of the platform, having BL2 as the Boot ROM is worth exploring. This way, you avoid the BL1_RW , BL2_PROGBITS memory overhead. BL2_NOPROGBITS will need to be in SRAM. See the BL2_AT_EL3 and BL2_IN_XIP_MEM build flags for details. This depends on BL31 being able to fit in the free space available after this is done. One option is using the RECLAIM_INIT_CODE option which reclaims BL31 init-only code for runtime data but it needs platform specific linker script support. There are other ways to reduce the BL31 size, but trading security like SEPARATE_CODE_AND_RODATA=0 or trading performance like USE_COHERENT_MEM=0.
Hope that helps.
Best Regards
Soby Mathew
From: 严鸿亮(鸿先) <hongxian.yhl(a)alibaba-inc.com<mailto:hongxian.yhl@alibaba-inc.com>>
Sent: 11 January 2020 06:04
To: Soby Mathew <Soby.Mathew(a)arm.com<mailto:Soby.Mathew@arm.com>>; Xie, Shaolin <shaolin.xie(a)alibaba-inc.com<mailto:shaolin.xie@alibaba-inc.com>>; tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>; Ash Wilding <Ash.Wilding(a)arm.com<mailto:Ash.Wilding@arm.com>>
Subject: 回复:[TF-A] MMU Table in ARM Trust-Firmware-A
Hi Soby,
Thanks for your replies.
Currently, out BL2 size is 60KB, BL1_RW is 28KB, BL31_PROGBITS is 48KB, BL31_NOPROGBITS is 24KB. For our testchip, we don't have too strictly security requirement, so maybe putting BL31 into DDR is a way to save SRAM and we don't need to worry about PROGBITS limit between BL31 and BL2.
For BL1_RW and BL2, there is 40KB used for MMU table. After I disable the MMU related code in arm_bl1_plat_arch_setup()/arm_bl2_plat_arch_setup() and also disable the build of xlat_table_lib, this 40KB space is saved. If the consequence is decreasing performance and losing MMU protection without any other functionality problem, then we might try this.
Best Regards
Yan Hongliang
------------------------------------------------------------------
发件人:Soby Mathew <Soby.Mathew(a)arm.com<mailto:Soby.Mathew@arm.com>>
发送时间:2020年1月10日(星期五) 18:27
收件人:"Xie, Shaolin" <shaolin.xie(a)alibaba-inc.com<mailto:shaolin.xie@alibaba-inc.com>>; tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org> <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
抄 送:nd <nd(a)arm.com<mailto:nd@arm.com>>; 严鸿亮(鸿先) <hongxian.yhl(a)alibaba-inc.com<mailto:hongxian.yhl@alibaba-inc.com>>; Ash Wilding <Ash.Wilding(a)arm.com<mailto:Ash.Wilding@arm.com>>
主 题:Re: [TF-A] MMU Table in ARM Trust-Firmware-A
On 10/01/2020 09:05, shaolin.xie via TF-A wrote:
> Hey all:
>
> We are trying to port ARM Trust-Firmware-A to our design, however, we are facing serious SRAM size problem.
>
> Our target SRAM is 64KB, but the compiled BL2 already taken 60K:
>
> After some evaluation, we found that the MMU table take most of the space. Our questions are:
Hi Shaolin,
There are some options to reduce the memory used for page-tables like
using non-identity virtual to physical mappings. But given your SRAM
size, I suspect you may not save enough to fit BL31.
>
> 1. Can we disable the MMU so we can fit the BL2 into 64KB space?
> (However, in ARM's porting guide, enable MMU and icache/dcache is mandatory. Refer to chapter 7.3 in https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-… <https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-…>.)
This is a possibility although not recommended for performance reasons
and you lose the protection of MMU during BL2 execution. This is not a
configuration we support an I suspect some changes to BL2 code may be
required for this.
>
> 2. In current design, BL31 is run in SRAM. If we enable DDR in BL2 and load BL31 image to DDR, is there any potential issue?
>
> Thanks in advances,
>
>
It is possible to create a secure carve-out in DDR and execute BL31 from
there. It is less `secure` than running from SRAM but it is acceptable
for some market segments depending on the threat model.
You target SRAM of 64 KB is on the lower side and fitting both BL2 and
BL31 in that space could be a challenge.
Could you let us know your BL2 and BL31 size and could you break down
the size in terms of PROGBITS and NOPROG BITS? The BL31 NOPROG BITS are
usually overlayed on top of BL2 memory and this will let us know whether
fitting both in SRAM is even possible. If both cannot fit together in
SRAM, there are other options you can explore like loading BL31 directly
from BootROM or using BL2 as an XIP BootROM image.
Best Regards
Soby Mathew
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On 10/01/2020 09:05, shaolin.xie via TF-A wrote:
> Hey all:
>
> We are trying to port ARM Trust-Firmware-A to our design, however, we are facing serious SRAM size problem.
>
> Our target SRAM is 64KB, but the compiled BL2 already taken 60K:
>
> After some evaluation, we found that the MMU table take most of the space. Our questions are:
Hi Shaolin,
There are some options to reduce the memory used for page-tables like
using non-identity virtual to physical mappings. But given your SRAM
size, I suspect you may not save enough to fit BL31.
>
> 1. Can we disable the MMU so we can fit the BL2 into 64KB space?
> (However, in ARM's porting guide, enable MMU and icache/dcache is mandatory. Refer to chapter 7.3 in https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-… <https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-…>.)
This is a possibility although not recommended for performance reasons
and you lose the protection of MMU during BL2 execution. This is not a
configuration we support an I suspect some changes to BL2 code may be
required for this.
>
> 2. In current design, BL31 is run in SRAM. If we enable DDR in BL2 and load BL31 image to DDR, is there any potential issue?
>
> Thanks in advances,
>
>
It is possible to create a secure carve-out in DDR and execute BL31 from
there. It is less `secure` than running from SRAM but it is acceptable
for some market segments depending on the threat model.
You target SRAM of 64 KB is on the lower side and fitting both BL2 and
BL31 in that space could be a challenge.
Could you let us know your BL2 and BL31 size and could you break down
the size in terms of PROGBITS and NOPROG BITS? The BL31 NOPROG BITS are
usually overlayed on top of BL2 memory and this will let us know whether
fitting both in SRAM is even possible. If both cannot fit together in
SRAM, there are other options you can explore like loading BL31 directly
from BootROM or using BL2 as an XIP BootROM image.
Best Regards
Soby Mathew
Another option to BL31 in system memory (DDR) is, which we are exploring,
is loading an image (in our case BL33/Uboot) to system caches (inner L1/L2
& outer LLC/L3 which ever) and initialize the DDR from within it. This is
not trivial though but working successfully with us for Cortex-A15, A53 and
A57 with CCN (Cache Coherent Network 504 and 512) featuring the Last Level
Cache on three of our SoCs.
Marek
On Fri, 10 Jan 2020 at 11:12, Soby Mathew via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> On 10/01/2020 09:05, shaolin.xie via TF-A wrote:
> > Hey all:
> >
> > We are trying to port ARM Trust-Firmware-A to our design, however, we
> are facing serious SRAM size problem.
> >
> > Our target SRAM is 64KB, but the compiled BL2 already taken 60K:
> >
> > After some evaluation, we found that the MMU table take most of the
> space. Our questions are:
> Hi Shaolin,
> There are some options to reduce the memory used for page-tables like
> using non-identity virtual to physical mappings. But given your SRAM
> size, I suspect you may not save enough to fit BL31.
>
> >
> > 1. Can we disable the MMU so we can fit the BL2 into 64KB space?
> > (However, in ARM's porting guide, enable MMU and icache/dcache is
> mandatory. Refer to chapter 7.3 in
> https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-…
> <
> https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-…
> >.)
>
> This is a possibility although not recommended for performance reasons
> and you lose the protection of MMU during BL2 execution. This is not a
> configuration we support an I suspect some changes to BL2 code may be
> required for this.
>
> >
> > 2. In current design, BL31 is run in SRAM. If we enable DDR in BL2 and
> load BL31 image to DDR, is there any potential issue?
> >
> > Thanks in advances,
> >
> >
>
> It is possible to create a secure carve-out in DDR and execute BL31 from
> there. It is less `secure` than running from SRAM but it is acceptable
> for some market segments depending on the threat model.
>
> You target SRAM of 64 KB is on the lower side and fitting both BL2 and
> BL31 in that space could be a challenge.
>
> Could you let us know your BL2 and BL31 size and could you break down
> the size in terms of PROGBITS and NOPROG BITS? The BL31 NOPROG BITS are
> usually overlayed on top of BL2 memory and this will let us know whether
> fitting both in SRAM is even possible. If both cannot fit together in
> SRAM, there are other options you can explore like loading BL31 directly
> from BootROM or using BL2 as an XIP BootROM image.
>
> Best Regards
> Soby Mathew
>
>
>
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>
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Slán,
Marek
Hey all:
We are trying to port ARM Trust-Firmware-A to our design, however, we are facing serious SRAM size problem.
Our target SRAM is 64KB, but the compiled BL2 already taken 60K:
After some evaluation, we found that the MMU table take most of the space. Our questions are:
1. Can we disable the MMU so we can fit the BL2 into 64KB space?
(However, in ARM's porting guide, enable MMU and icache/dcache is mandatory. Refer to chapter 7.3 in https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-… <https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/porting-…>.)
2. In current design, BL31 is run in SRAM. If we enable DDR in BL2 and load BL31 image to DDR, is there any potential issue?
Thanks in advances,
Back on-list.
> One more question, the operation of TrustZone is the same in the armv7-A and Armv8-A architectures, right?
Not exactly…for a description about TZ differences between the Armv7-A and Armv8-A architecture please have a look at this presentation:
https://www.youtube.com/watch?v=q32BEMMxmfwhttps://www.slideshare.net/linaroorg/arm-trusted-firmareforarmv8alcu13
As a reference, all public talks and presentations on TF-A over the years are listed here:
https://developer.trustedfirmware.org/w/tf_a/
Thanks
Matteo
> From: Iñigo Vicente Waliño <inigovicentewalino(a)gmail.com>
> Sent: 09 January 2020 11:21
> To: Matteo Carlini <Matteo.Carlini(a)arm.com>
> Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
> One more question, the operation of TrustZone is the same in the armv7-A and Armv8-A architectures, right?
> Thanks for your answers,
> Iñigo.
Another option is to look at the 96boards platforms:
https://www.96boards.org/product/developerbox/ (that's supported upstream by TF-A https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/plat/socio… )
and the Secure96 mezzanine board
https://www.96boards.org/product/secure96/https://www.96boards.org/blog/getting-started-with-the-secure96-tpm/
but the boot flow with TF-A and this mezzanine board hasn't been officially proved.
Ard and Stuart (cc-ed) have done some investigations and experiment in this direction and might add something.
Thanks
Matteo
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Dan
> Handley via TF-A
> Sent: 09 January 2020 09:56
> To: tf-a(a)lists.trustedfirmware.org
> Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> (Back on the list)
>
> Sorry Iñigo, I don't know enough about the hw capabilities of Raspberry Pi
> and its boot flow to be able to help you further. Olivier gave some more
> pointers.
>
> Dan.
>
>
> From: Iñigo Vicente Waliño <inigovicentewalino(a)gmail.com>
> Sent: 09 January 2020 07:42
> To: Dan Handley <Dan.Handley(a)arm.com>
> Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> Yes, thank you very much.
>
> Then, what I'm trying to say is that if I want a secure boot, I need a trust root.
> If Raspberry Pi cannot provide that trusted root, can I use a TPM?
>
> Iñigo
>
> El mié., 8 ene. 2020 a las 16:32, Dan Handley via TF-A (<tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>)
> escribió:
> (Back on the list)
>
> By rpi I guess you mean Raspberry Pi?
>
> > How do we ensure that the ROM is safe?
> I'm not sure what you mean by "safe". By definition the ROM is non-
> modifiable but maybe you also want it to be non-readable by normal world
> software?
>
> Although Raspberry Pi contains CPUs that implement TrustZone, I believe
> there is no TrustZone Controller IP policing access to memory so there is
> nothing preventing normal world software from accessing memory that is
> mapped in as secure. Perhaps that is what you mean by "rpi does not provide
> security"? I also don't know what you mean by "a TPM does not work".
>
> Dan.
>
> From: Iñigo Vicente Waliño
> <inigovicentewalino(a)gmail.com<mailto:inigovicentewalino@gmail.com>>
> Sent: 08 January 2020 14:54
> To: Dan Handley <Dan.Handley(a)arm.com<mailto:Dan.Handley@arm.com>>
> Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> Assuming that BL1 is used and implemented in ROM, for example, with an rpi.
> How do we ensure that the ROM is safe? He sought that rpi does not provide
> security and that a TPM does not work. Why?
>
> Thanks.
>
> El mié., 8 ene. 2020 a las 13:21, Dan Handley via TF-A (<tf-
> a(a)lists.trustedfirmware.org<mailto:tf-
> a(a)lists.trustedfirmware.org><mailto:tf-
> a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>>)
> escribió:
> Hi Inigo
>
> TrustZone is a trademark referring to the security extensions of the Arm
> architecture. That is separate to BL1, which is the first boot stage of Trusted
> Firmware-A (or some other equivalent boot firmware). The expectation is
> that BL1, if used, is implemented in ROM to provide the Root of Trust for the
> Application Processor (AP).
>
> An alternative flow is for a separate "security processor" to authenticate the
> AP firmware before the AP is released from reset. In such a flow, there is no
> need for BL1 and BL2 since that functionality is provided by the security
> processor. In such a flow, the TF-A RESET_TO_BL31 config can be used (see
> in-source documentation).
>
> A TPM can provide additional security by storing secrets not even visible to
> TrustZone software (e.g. root keys or boot measurements). However, TPMs
> typically don't do firmware authentication on their own; some other
> software will need to use the secrets it stores, e.g. boot firmware may ask
> the TPM verify a signature corresponding to the next boot stage.
>
> > If the TPM is changed to another, is the boot performed?
> That depends on your system design.
>
> Dan.
>
> > -----Original Message-----
> > From: TF-A
> > <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trus
> > tedfirmware.org><mailto:tf-a-bounces@lists.trustedfirmware.org<mailto:
> > tf-a-bounces(a)lists.trustedfirmware.org>>> On Behalf Of Iñigo Vicente
> > Waliño via TF-A
> > Sent: 08 January 2020 10:33
> > To:
> > tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org><
> > mailto:tf-a@lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmwar
> > e.org>>
> > Subject: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
> >
> > Hi,
> >
> > Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used
> as
> > a trusted root or is it useless?
> > If the TPM is changed to another, is the boot performed?
> >
> > Thanks,
> > Inigo.
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org><
> > mailto:TF-A@lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmwar
> > e.org>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
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(Back on the list)
Sorry Iñigo, I don't know enough about the hw capabilities of Raspberry Pi and its boot flow to be able to help you further. Olivier gave some more pointers.
Dan.
From: Iñigo Vicente Waliño <inigovicentewalino(a)gmail.com>
Sent: 09 January 2020 07:42
To: Dan Handley <Dan.Handley(a)arm.com>
Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
Yes, thank you very much.
Then, what I'm trying to say is that if I want a secure boot, I need a trust root. If Raspberry Pi cannot provide that trusted root, can I use a TPM?
Iñigo
El mié., 8 ene. 2020 a las 16:32, Dan Handley via TF-A (<tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>) escribió:
(Back on the list)
By rpi I guess you mean Raspberry Pi?
> How do we ensure that the ROM is safe?
I'm not sure what you mean by "safe". By definition the ROM is non-modifiable but maybe you also want it to be non-readable by normal world software?
Although Raspberry Pi contains CPUs that implement TrustZone, I believe there is no TrustZone Controller IP policing access to memory so there is nothing preventing normal world software from accessing memory that is mapped in as secure. Perhaps that is what you mean by "rpi does not provide security"? I also don't know what you mean by "a TPM does not work".
Dan.
From: Iñigo Vicente Waliño <inigovicentewalino(a)gmail.com<mailto:inigovicentewalino@gmail.com>>
Sent: 08 January 2020 14:54
To: Dan Handley <Dan.Handley(a)arm.com<mailto:Dan.Handley@arm.com>>
Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
Assuming that BL1 is used and implemented in ROM, for example, with an rpi.
How do we ensure that the ROM is safe? He sought that rpi does not provide security and that a TPM does not work. Why?
Thanks.
El mié., 8 ene. 2020 a las 13:21, Dan Handley via TF-A (<tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org><mailto:tf-a@lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>>) escribió:
Hi Inigo
TrustZone is a trademark referring to the security extensions of the Arm architecture. That is separate to BL1, which is the first boot stage of Trusted Firmware-A (or some other equivalent boot firmware). The expectation is that BL1, if used, is implemented in ROM to provide the Root of Trust for the Application Processor (AP).
An alternative flow is for a separate "security processor" to authenticate the AP firmware before the AP is released from reset. In such a flow, there is no need for BL1 and BL2 since that functionality is provided by the security processor. In such a flow, the TF-A RESET_TO_BL31 config can be used (see in-source documentation).
A TPM can provide additional security by storing secrets not even visible to TrustZone software (e.g. root keys or boot measurements). However, TPMs typically don't do firmware authentication on their own; some other software will need to use the secrets it stores, e.g. boot firmware may ask the TPM verify a signature corresponding to the next boot stage.
> If the TPM is changed to another, is the boot performed?
That depends on your system design.
Dan.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org><mailto:tf-a-bounces@lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>>> On Behalf Of Iñigo
> Vicente Waliño via TF-A
> Sent: 08 January 2020 10:33
> To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org><mailto:tf-a@lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
> Subject: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> Hi,
>
> Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used as a
> trusted root or is it useless?
> If the TPM is changed to another, is the boot performed?
>
> Thanks,
> Inigo.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org><mailto:TF-A@lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>>
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
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Hi,
To add to Dan's observation about rpi lacking TZ memory controller:
Notice the first subsystem to boot on BCM SoC is the VideoCore (which itself releases ARM cores resets). Thus, there are early boot stages running even before TF-A gets handed over. So it needs trusting the VC ROM and VC bootloader (residing on SD card, or EEPROM from rpi4). As to whether those early components get verified by the BCM chip, this is not documented publicly AFAIK.
I extrapolate "TPM does not work" means the "public rpi" is good for prototyping TZ and/or a TPM solution. Although it is eventually not directly usable as a production platform for such use cases.
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Dan Handley via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 08 January 2020 16:32
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
(Back on the list)
By rpi I guess you mean Raspberry Pi?
> How do we ensure that the ROM is safe?
I'm not sure what you mean by "safe". By definition the ROM is non-modifiable but maybe you also want it to be non-readable by normal world software?
Although Raspberry Pi contains CPUs that implement TrustZone, I believe there is no TrustZone Controller IP policing access to memory so there is nothing preventing normal world software from accessing memory that is mapped in as secure. Perhaps that is what you mean by "rpi does not provide security"? I also don't know what you mean by "a TPM does not work".
Dan.
From: Iñigo Vicente Waliño <inigovicentewalino(a)gmail.com>
Sent: 08 January 2020 14:54
To: Dan Handley <Dan.Handley(a)arm.com>
Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
Assuming that BL1 is used and implemented in ROM, for example, with an rpi.
How do we ensure that the ROM is safe? He sought that rpi does not provide security and that a TPM does not work. Why?
Thanks.
El mié., 8 ene. 2020 a las 13:21, Dan Handley via TF-A (<tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>) escribió:
Hi Inigo
TrustZone is a trademark referring to the security extensions of the Arm architecture. That is separate to BL1, which is the first boot stage of Trusted Firmware-A (or some other equivalent boot firmware). The expectation is that BL1, if used, is implemented in ROM to provide the Root of Trust for the Application Processor (AP).
An alternative flow is for a separate "security processor" to authenticate the AP firmware before the AP is released from reset. In such a flow, there is no need for BL1 and BL2 since that functionality is provided by the security processor. In such a flow, the TF-A RESET_TO_BL31 config can be used (see in-source documentation).
A TPM can provide additional security by storing secrets not even visible to TrustZone software (e.g. root keys or boot measurements). However, TPMs typically don't do firmware authentication on their own; some other software will need to use the secrets it stores, e.g. boot firmware may ask the TPM verify a signature corresponding to the next boot stage.
> If the TPM is changed to another, is the boot performed?
That depends on your system design.
Dan.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>> On Behalf Of Iñigo
> Vicente Waliño via TF-A
> Sent: 08 January 2020 10:33
> To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
> Subject: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> Hi,
>
> Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used as a
> trusted root or is it useless?
> If the TPM is changed to another, is the boot performed?
>
> Thanks,
> Inigo.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
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IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
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https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi,
We are intending to move the updates to the change log from completely release based to more rolling updates. I have created a new change log file in the docs directory (change-log-upcoming.rst) for changes that need to be included for the upcoming release: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3081. The intention is for individual developers to update the document with the relevant patch as the code change is being made. The usual change log document (docs/change-log.rst) will be updated at release time to include all changes for each release.
Thanks,
Lauren
(Back on the list)
By rpi I guess you mean Raspberry Pi?
> How do we ensure that the ROM is safe?
I'm not sure what you mean by "safe". By definition the ROM is non-modifiable but maybe you also want it to be non-readable by normal world software?
Although Raspberry Pi contains CPUs that implement TrustZone, I believe there is no TrustZone Controller IP policing access to memory so there is nothing preventing normal world software from accessing memory that is mapped in as secure. Perhaps that is what you mean by "rpi does not provide security"? I also don't know what you mean by "a TPM does not work".
Dan.
From: Iñigo Vicente Waliño <inigovicentewalino(a)gmail.com>
Sent: 08 January 2020 14:54
To: Dan Handley <Dan.Handley(a)arm.com>
Subject: Re: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
Assuming that BL1 is used and implemented in ROM, for example, with an rpi.
How do we ensure that the ROM is safe? He sought that rpi does not provide security and that a TPM does not work. Why?
Thanks.
El mié., 8 ene. 2020 a las 13:21, Dan Handley via TF-A (<tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>) escribió:
Hi Inigo
TrustZone is a trademark referring to the security extensions of the Arm architecture. That is separate to BL1, which is the first boot stage of Trusted Firmware-A (or some other equivalent boot firmware). The expectation is that BL1, if used, is implemented in ROM to provide the Root of Trust for the Application Processor (AP).
An alternative flow is for a separate "security processor" to authenticate the AP firmware before the AP is released from reset. In such a flow, there is no need for BL1 and BL2 since that functionality is provided by the security processor. In such a flow, the TF-A RESET_TO_BL31 config can be used (see in-source documentation).
A TPM can provide additional security by storing secrets not even visible to TrustZone software (e.g. root keys or boot measurements). However, TPMs typically don't do firmware authentication on their own; some other software will need to use the secrets it stores, e.g. boot firmware may ask the TPM verify a signature corresponding to the next boot stage.
> If the TPM is changed to another, is the boot performed?
That depends on your system design.
Dan.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>> On Behalf Of Iñigo
> Vicente Waliño via TF-A
> Sent: 08 January 2020 10:33
> To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
> Subject: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> Hi,
>
> Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used as a
> trusted root or is it useless?
> If the TPM is changed to another, is the boot performed?
>
> Thanks,
> Inigo.
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Hi Inigo
TrustZone is a trademark referring to the security extensions of the Arm architecture. That is separate to BL1, which is the first boot stage of Trusted Firmware-A (or some other equivalent boot firmware). The expectation is that BL1, if used, is implemented in ROM to provide the Root of Trust for the Application Processor (AP).
An alternative flow is for a separate "security processor" to authenticate the AP firmware before the AP is released from reset. In such a flow, there is no need for BL1 and BL2 since that functionality is provided by the security processor. In such a flow, the TF-A RESET_TO_BL31 config can be used (see in-source documentation).
A TPM can provide additional security by storing secrets not even visible to TrustZone software (e.g. root keys or boot measurements). However, TPMs typically don't do firmware authentication on their own; some other software will need to use the secrets it stores, e.g. boot firmware may ask the TPM verify a signature corresponding to the next boot stage.
> If the TPM is changed to another, is the boot performed?
That depends on your system design.
Dan.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Iñigo
> Vicente Waliño via TF-A
> Sent: 08 January 2020 10:33
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] Does ARMv8 TrustZone provide a secure ROM?
>
> Hi,
>
> Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used as a
> trusted root or is it useless?
> If the TPM is changed to another, is the boot performed?
>
> Thanks,
> Inigo.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used as a
trusted root or is it useless?
If the TPM is changed to another, is the boot performed?
Thanks,
Inigo.
Hi,
Does ARMv8 TrustZone provide BL1 in a secure ROM? Can a TPM be used as a
trusted root or is it useless?
If the TPM is changed to another, is the boot performed?
Thanks,
Inigo.
Hi Sumit,
On 1/8/20 7:09 AM, Sumit Garg via TF-A wrote:
> Hi Sandrine,
>
> On Fri, 20 Dec 2019 at 12:29, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>
>> Hi Sandrine,
>>
>> On Wed, 18 Dec 2019 at 21:07, Sandrine Bailleux
>> <Sandrine.Bailleux(a)arm.com> wrote:
>>>
>>> Hi Sumit,
>>>
>>> I've started providing some early review comments on your patches in
>>> Gerrit but these are mainly about implementation details. I would like
>>> to continue the higher-level design discussions here in parallel on the
>>> mailing list, if that's fine with you.
>>>
>>
>> Yes that's perfectly fine with me.
>>
>
> Do you have any further comments? As I have already incorporated most
> of the your comments related to design and implementation details in
> latest v4 patch-set [1].
>
> [1] https://review.trustedfirmware.org/q/topic:%22tbbr%252Ffw_enc%22+(status:op…
Apologies, with the Christmas break, I haven't had a chance to look at
your patches again. I will allocate some time for it this week and get
back to you.
Regards,
Sandrine
Hi Sumit,
I've started providing some early review comments on your patches in
Gerrit but these are mainly about implementation details. I would like
to continue the higher-level design discussions here in parallel on the
mailing list, if that's fine with you.
On 12/6/19 1:29 PM, Sumit Garg via TF-A wrote:
> Hi Sandrine,
>
> On Thu, 5 Dec 2019 at 20:31, Sandrine Bailleux
> <Sandrine.Bailleux(a)arm.com> wrote:
>>>> Also, I am still trying to get my head around how this would integrate
>>>> with a cryptographic engine where the key does not leave the chip. I can
>>>> imagine that we could get the address of the encrypted firmware image
>>>> from the FIP, pass that to a cryptographic engine, request it to decrypt
>>>> it and store the result somewhere in Trusted RAM. In this case, we
>>>> wouldn't call plat_get_fip_encryption_key(). Do you have any idea how we
>>>> would pull this off? Like how the different modules (IO layer, crypto
>>>> module, image parser module, ...) would integrate together?
>>>
>>> In this case, I would expect platform to provide key identifier rather
>>> than actual key as part of plat_get_fip_encryption_key() which is then
>>> passed onto auth_decrypt() that is implementation specific to
>>> cryptographic engine in similar terms as currently done for mbedTLS
>>> backend.
>>
>> Ah I see, so plat_get_fip_encryption_key() could return either the key
>> itself or a key identifier. Just like plat_get_rotpk_info() can return
>> either the key or a hash of it today. However, in the case of
>> plat_get_rotpk_info(), it also returns some flags indicating which one
>> it is. Don't we need something similar for
>> plat_get_fip_encryption_key()? How will the crypto module be able to
>> tell the difference between a key and a key ID otherwise? Or would you
>> expect a given crypto module backend to always use either keys or key
>> IDs, but not both?
>>
>
> It perfectly makes sense for crypto module backend to support both key
> ID and actual key. But I was thinking from use-case perspective that
> why would one like to expose key to the firmware if the crypto module
> could better protect it. And I could come up with one use-case where
> the SSK (burnt in SoC fuses) is provided as an actual key and BSSK
> (accessible only to crypto module) is provided via a key ID.
Yes, that makes sense to me.
> So yes I agree with you to provide additional flags field along with
> key buffer. Also, I think it makes sense to rename
> "plat_get_fip_encryption_key()" to "plat_get_fip_enc_key_info()".
Agree.
>>>> I have some concerns around the generation of the initialization vectors
>>>> in the encrypt_fw tool. Right now, IVs are simply a random sequence of
>>>> bytes (obtained through a call to OpenSSL's RAND_bytes() API). Now, I
>>>> would imagine that RAND_bytes() is typically based on a good random
>>>> number generator and thus will generate different sequences every time
>>>> it is called. At least, as long as it is called from the same machine
>>>> every time. But what if we encrypt a new FIP bundle from a different
>>>> machine, say in the context of a firmware update? Is it not possible
>>>> that it might choose the same IV out of bad luck?
>>>>
>>>> Perhaps that's an issue left to provisioning/manufacturing time and is
>>>> out of the scope here. But it worries me because AFAIU, the security of
>>>> AES-GCM is critically undermined if the same nonce is used multiple
>>>> times with the same key (see section 5.1.1. "Nonce reuse" in RFC 5116).
>>>> If the encryption key is the SSK (rather than the BSSK) then I guess the
>>>> probability is even higher, as it is shared amongst a class of devices.
>>>>
>>>
>>> Agree that "nonce" should be unique and using a random number
>>> generator available on build machine was an effort towards that. But
>>> thinking about the case that you have mentioned, I think we could have
>>> an optional user provided "nonce" as an input to "encrypt_fw" tool, so
>>> that the user is aware to randomly generate and provide a unique
>>> nonce.
>>
>> Yes, I like your suggestion of specifying the nonce to the tool. But I
>> think it should be the default behaviour then. You mention an *optional*
>> user-provided nonce, I would like to suggest we make this mandatory
>> instead. We could provide an option to request the tool to generate the
>> nonce, intended for development purposes.
>>
>
> Making nonce as default and mandatory command line option seems to be
> overkill for a user. It may also lead to unsafe practices of
> hardcoding a nonce in Makefile, shell scripts etc. So I think we
> should keep this as optional only for a narrow use-case where people
> might not trust uniqueness property of RNG from multiple build
> machines.
I don't know... Hard-coding a nonce in the makefile is unsafe for sure
but I would think that a nonce generated by the tool is also unsafe
without proper management of these nonces across keys and devices, but
in a much more subtle manner. I still think the nonce generation would
be better left outside of the scope of this tool.
> BTW, I have already added nonce command line option as part of v3
> patch-set [1]. Please have a look.
>
> [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2496/2..3
>
>>>> Impact on memory footprint and performance
>>>> ------------------------------------------
>>>>
>>>> Do you know what the performance impact is when this feature is enabled
>>>> in TF-A, to decrypt images at boot time? Obviously it depends on the
>>>> platform and whether there is a dedicated cryptographic engine, and I
>>>> suppose you cannot really get any relevant measurements out of QEMU but
>>>> I would be interested if you've got any rough numbers.
>>>
>>> Following are measurements based on qemu for mbedTLS software library
>>> based authenticated decryption:
>>>
>>> BL31 plain:
>>> NOTICE: Load image time: 137us, size: 28KB
>>> BL31 encrypted:
>>> NOTICE: Load image time: 3979us, size: 28KB
>>>
>>> BL32 plain:
>>> NOTICE: Load image time: 1791us, size: 360KB
>>> BL32 encrypted:
>>> NOTICE: Load image time: 36339us, size: 360KB
>>
>> Thanks. So it's a 29% increase for BL31 and 20% for BL32. I would have
>> naively expected similar percentages, any idea why we get such a
>> difference between BL31 and BL32? I am just curious. Maybe it's down to
>> how the crypto algorithm/mode of operation works under the hood?
>
> Yes this additional increase for BL31 seems to be due to one time
> initialization operations carried on first invocation of mbedTLS gcm
> APIs, especially time taken to generate AES tables (see call to
> aes_gen_tables() in mbedtls/library/aes.c +576).
Ah I see, thanks for the explanation.
Regarding the memory impact, given that it's adding quite a bit of code
and data (around 9KB for BL1 and 12KB for BL2 from what you were saying
in a previous email), I think we need to make this feature optional and
wrap it under a build flag. Not everyone will need to encrypt firmware
images, having only authentication is a valid use case as well. If I am
not mistaken, your patches right now unconditionally pull the mbedTLS
primitives into BL1 and BL2 (as long as TBBR is enabled of course).
As a matter of fact, I am not able to build BL1 on FVP platform with
your patches, presumably due to the unconditional size increase. The
following build command:
> make TRUSTED_BOARD_BOOT=1 ARM_ROTPK_LOCATION=devel_rsa
MBEDTLS_DIR=mbedtls bl1
... fails at link time:
aarch64-linux-gnu-ld.bfd: build/fvp/release/bl1/bl1.elf section
`xlat_table' will not fit in region `RAM'
aarch64-linux-gnu-ld.bfd: BL1's RW section has exceeded its limit.
aarch64-linux-gnu-ld.bfd: region `RAM' overflowed by 4096 bytes
Makefile:889: recipe for target 'build/fvp/release/bl1/bl1.elf' failed
Regards,
Sandrine
Hi
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Soby Mathew
> via TF-A
> Sent: 06 January 2020 12:34
> To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf-a(a)lists.trustedfirmware.org;
> Sheetal Tigadoli <sheetal.tigadoli(a)broadcom.com>
> Cc: nd <nd(a)arm.com>
> Subject: Re: [TF-A] [Question] Why are the log related macros defined in
> multiple of 10's
>
> > Hi All,
> >
> > I wanted to understand the reason behind defining LOG_LEVEL_* macros
> > as multiple of 10's, also same goes with LOG_MARKER_* macros.
> > If we set the LOG macros to 1,2,3 and so on, we can avoid the mod and
> > division operation when printing the msgs to console.
> >
> > Please let me your thoughts on this.
> >
> > Link to this question on Phabricator -
> > https://developer.trustedfirmware.org/T624
> >
> > Thanks
> > Sheetal
>
As Sandrine said in Phabricator, the reason was simply to leave space between the levels to allow adding intermediate levels without breaking compatibility. Compatibility was a possible concern if external tools used the log level and you only rebuilt some of the TF-A components (components could end up using different values). However, I suspect the actual level value is never emitted in practice (just the text prefix) so this may not be a real concern.
> Hi Sheetal
> I didn't quite get reason for the optimization from multiples of 10 to
> consecutive numbers. The mod operation you refer to are assertions which will
> be compiled out when DEBUG=0 or when ENABLE_ASSSERTIONS=0. Other than that
> there is a single divide by 10 operation within the default implementation of
> plat_log_get_prefix().
>
>
> If the logging utility is considered performance critical, removing the
> single divide by 10 will not result in any gain. Usually the bottleneck for
> logs are UART baudrates and the CPU spends most of time spinning in a wait
> loop for UART to be free. Hence I don't see any need for change for log
> levels macro if the intent is performance optimization.
>
+1. Unless there's an actual performance gain, this sounds like an unnecessary change.
Dan.
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On 06/01/2020 12:34, Soby Mathew via TF-A wrote:
>> Hi All,
>>
>> I wanted to understand the reason behind defining LOG_LEVEL_* macros as
>> multiple of 10's, also same goes with LOG_MARKER_* macros.
>> If we set the LOG macros to 1,2,3 and so on, we can avoid the mod and
>> division operation when printing the msgs to console.
>>
>> Please let me your thoughts on this.
>>
>> Link to this question on Phabricator -
>> https://developer.trustedfirmware.org/T624
>>
>> Thanks
>> Sheetal
>
> Hi Sheetal
> I didn't quite get reason for the optimization from multiples of 10 to
> consecutive numbers. The mod operation you refer to are assertions which
> will be compiled out when DEBUG=0 or when ENABLE_ASSSERTIONS=0. Other
> than that there is a single divide by 10 operation within the default
> implementation of plat_log_get_prefix().
>
>
> If the logging utility is considered performance critical, removing the
> single divide by 10 will not result in any gain. Usually the bottleneck
> for logs are UART baudrates and the CPU spends most of time spinning in
> a wait loop for UART to be free. Hence I don't see any need for change
> for log levels macro if the intent is performance optimization.
>
> Best Regards
> Soby Mathew
>
Hi Sheetal
There is some discussion related to this here :
https://github.com/ARM-software/tf-issues/issues/462 and see associated
issues and PRs for more details.
Best Regards
Soby Mathew
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>
>
> Hi All,
>
> I wanted to understand the reason behind defining LOG_LEVEL_* macros as
> multiple of 10's, also same goes with LOG_MARKER_* macros.
> If we set the LOG macros to 1,2,3 and so on, we can avoid the mod and
> division operation when printing the msgs to console.
>
> Please let me your thoughts on this.
>
> Link to this question on Phabricator -
> https://developer.trustedfirmware.org/T624
>
> Thanks
> Sheetal
Hi Sheetal
I didn't quite get reason for the optimization from multiples of 10 to
consecutive numbers. The mod operation you refer to are assertions which
will be compiled out when DEBUG=0 or when ENABLE_ASSSERTIONS=0. Other
than that there is a single divide by 10 operation within the default
implementation of plat_log_get_prefix().
If the logging utility is considered performance critical, removing the
single divide by 10 will not result in any gain. Usually the bottleneck
for logs are UART baudrates and the CPU spends most of time spinning in
a wait loop for UART to be free. Hence I don't see any need for change
for log levels macro if the intent is performance optimization.
Best Regards
Soby Mathew
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
Hi Varun
Could you take a look at the Nvidia driver defect reported by the Coverity scan?
Regards.
Alexei.
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of scan-admin--- via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 03 January 2020 08:19
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] New Defects reported by Coverity Scan for ARM-software/arm-trusted-firmware
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 352832: Uninitialized variables (UNINIT)
/plat/nvidia/tegra/soc/t194/drivers/mce/nvg.c: 197 in nvg_update_ccplex_gsc()
________________________________________________________________________________________________________
*** CID 352832: Uninitialized variables (UNINIT)
/plat/nvidia/tegra/soc/t194/drivers/mce/nvg.c: 197 in nvg_update_ccplex_gsc()
191 ret = EINVAL;
192 } else {
193 nvg_set_request_data((uint64_t)TEGRA_NVG_CHANNEL_UPDATE_CCPLEX_GSC,
194 (uint64_t)gsc_idx);
195 }
196
>>> CID 352832: Uninitialized variables (UNINIT)
>>> Using uninitialized value "ret".
197 return ret;
198 }
199
200 /*
201 * Cache clean operation for all CCPLEX caches.
202 */
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/wf/click?upn=08onrYu34A-2BWcWUl-2F-2BfV0V0…
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Hi Sheetal,
Your remark/question makes sense.
The original requirement is described here: https://github.com/ARM-software/tf-issues/issues/232
We may get further update from Dan, but I sense this was to provision for intermediate log levels (as stated by Sandrine on phabricator).
Will you be able to submit a patch for this?
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Sheetal Tigadoli via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 20 December 2019 15:48
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] [Question] Why are the log related macros defined in multiple of 10's
Hi All,
I wanted to understand the reason behind defining LOG_LEVEL_* macros as
multiple of 10's, also same goes with LOG_MARKER_* macros.
If we set the LOG macros to 1,2,3 and so on, we can avoid the mod and
division operation when printing the msgs to console.
Please let me your thoughts on this.
Link to this question on Phabricator -
https://developer.trustedfirmware.org/T624
Thanks
Sheetal
--
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TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi All,
I wanted to understand the reason behind defining LOG_LEVEL_* macros as
multiple of 10's, also same goes with LOG_MARKER_* macros.
If we set the LOG macros to 1,2,3 and so on, we can avoid the mod and
division operation when printing the msgs to console.
Please let me your thoughts on this.
Link to this question on Phabricator -
https://developer.trustedfirmware.org/T624
Thanks
Sheetal
Hi All,
I wanted to understand the reason behind defining LOG_LEVEL_* macros as
multiple of 10's, also same goes with LOG_MARKER_* macros.
If we set the LOG macros to 1,2,3 and so on, we can avoid the mod and
division operation when printing the msgs to console.
Please let me your thoughts on this.
Link to this question on Phabricator -
https://developer.trustedfirmware.org/T624
Thanks
Sheetal
>
> Subject: [PATCH] rpi3/4: Add support for offlining CPUs
> From: Jan Kiszka <jan.kiszka(a)siemens.com>
>
> The hooks were populated but the power down left the CPU in limbo-land.
> What we need to do - until there is a way to actually power off - is to
> turn off the MMU and enter the spinning loop as if we were cold-booted.
> This allows the on-call to pick up the CPU again.
>
> Signed-off-by: Jan Kiszka <jan.kiszka(a)siemens.com>
> ---
> plat/rpi/common/rpi3_pm.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/plat/rpi/common/rpi3_pm.c b/plat/rpi/common/rpi3_pm.c
> index 8c2d070c4..2a6bf076b 100644
> --- a/plat/rpi/common/rpi3_pm.c
> +++ b/plat/rpi/common/rpi3_pm.c
> @@ -123,6 +123,15 @@ static void rpi3_pwr_domain_off(const psci_power_state_t *target_state)
> #endif
> }
>
> +void __dead2 plat_secondary_cold_boot_setup(void);
> +
> +static void __dead2
> +rpi3_pwr_domain_pwr_down_wfi(const psci_power_state_t *target_state)
> +{
> + disable_mmu_el3();
> + plat_secondary_cold_boot_setup();
> +}
> +
> /*******************************************************************************
> * Platform handler called when a power domain is about to be turned on. The
> * mpidr determines the CPU to be turned on.
> @@ -224,6 +233,7 @@ static void __dead2 rpi3_system_off(void)
> static const plat_psci_ops_t plat_rpi3_psci_pm_ops = {
> .cpu_standby = rpi3_cpu_standby,
> .pwr_domain_off = rpi3_pwr_domain_off,
> + .pwr_domain_pwr_down_wfi = rpi3_pwr_domain_pwr_down_wfi,
> .pwr_domain_on = rpi3_pwr_domain_on,
> .pwr_domain_on_finish = rpi3_pwr_domain_on_finish,
> .system_off = rpi3_system_off,
> --
> 2.16.4
>
Hi Jan,
I have put in a suggestion for the change. Basically, if you are able to
do a `reset` before spinning in `plat_secondary_cold_boot_setup()`, that
would be ideal. Also, if `plat_secondary_cold_boot_setup()` can trap the
primary CPU as well if it were to be offlined, then I think your changes
should be good.
Best Regards
Soby Mathew
Hi Jisheng,
This is due to the power management requirement of GICv3. In section 7.1 of GICv3 specification : https://static.docs.arm.com/ihi0069/c/IHI0069C_gic_architecture_specificati…
It says the that " Before powering down the CPU interface and the PE when the Redistributor is powered up, software must put the interface between the CPU interface and the Redistributor into the quiescent state or the system will become UNPREDICTABLE".
In order to put the Redistributor in a quiescent state, all the group enables in CPU interface must be disabled , otherwise "setting GICR_WAKER.ProcessorSleep to 1 when the physical group enables in the CPU interface are set to 1 results in UNPREDICTABLE behavior."
Hope that clarifies.
Best Regards
Soby Mathew
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Jisheng
> Zhang via TF-A
> Sent: 05 December 2019 10:31
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] About disable gic cpuif in psci suspend or off
>
> Hi,
>
> In ATF-A, I usually see below code in psci suspend or off code path:
>
> /* Prevent interrupts from spuriously waking up this cpu */
> plat_arm_gic_cpuif_disable();
>
> But per my understanding, before calling psci_suspend(), the NW, e.g linux
> kernel has disabled all interrupts from cpu level, so here preventing interrupt is
> to prevent the interrupts from secure world?
>
> Another question is: for Cortex A55, this is not necessary. Because
> CA55 TRM says when the core_pwrdn_en bit is set, executing WFI
> automatically masks all interrupts and wake-up events in the core. Am I right?
>
> Thanks in advance
> --
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Julius,
On the subject of DebugFS's purpose it was envisages and is today as Sandrine describes as a debug build only capability. Saying that though there has been some early thoughts that it could evolve into a Secure Debug feature where this type of capability or something like it is always on requiring debug certificates for authenticated access. This is something very much for a possible future evolution and is not in the patches available today. We would welcome any thoughts on such an evolution in this space.
Joanna
On 13/12/2019, 13:01, "TF-A on behalf of Sandrine Bailleux via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Julius,
OK, in that case I can see that a solution based on TF-A's DebugFS
interface might not be desirable. Indeed, our original intention was to
make the whole DebugFS system a debug-only feature (hence its name!). As
such, I agree that it is likely not to get the same level of scrutiny
and testing as other features intended for production systems.
One of the main use cases we have in mind for DebugFS is, being able to
peek and poke into the firmware for testing purposes. Today, when doing
functional testing from the normal world (for example, using TF-A
Tests), we are limited to what's exposed through the SMC interface. And
even then, we have limited visibility on what really happened in the
firmware, as we can only deduce so much from the SMC return value(s).
DebugFS could be used to bridge this gap, by providing a side channel
for getting internal firmware state information.
Going back to the SMC-based solution then, I am not quite convinced
SYSTEM_RESET2 is the right interface for intentionally triggering a
panic in TF-A. I think the semantics do not quite match. If anything, a
firmware crash seems more like a shutdown operation to me rather than a
reset (we don't recover from a firmware crash). I am not even sure we
should look into the PSCI SMC range, as it's not a power-management
operation.
Julius, you wrote:
> It's the same problem that the SMC/PSCI spec and the TF repository layout is only designed to deal with generic vs. SoC-vendor-specific differentiation. If the normal world OS needs a feature, we can only make it generic or duplicate it across all vendors running that OS.
So it sounds like it's not the first time that you hit this issue, is
it? Do you have any other example of Normal World OS feature you would
have liked to expose through a generic SMC interface? I am wondering
whether this could help choosing the right SMC range, if we can identify
some common criteria among a set of such features.
Regards,
Sandrine
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Hi Louis,
The term PAL is also used for platform abstraction layer so it "could" be confusing to have this being used for something different.
Not necessarily suggesting to change anything but it might be worth considering this aspect.
Thanks,
Abhishek
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Louis Mayencourt via TF-A
Sent: 19 November 2019 13:40
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Design proposal: Property Access Layer
Hi everyone,
Please let me introduce the `Property Access Layer` prototype:
The Property Access Layer (PAL) is an abstraction layer for platform specific data, allowing a "property" to be queried and a value retrieved without the requesting entity knowing what backing store is being used to hold the data. It is used to bridge new and old ways of providing platform-specific data:
Today, information like the Chain of Trust is held within several, nested platform-defined tables. In the future, it may be provided as part of a device tree blob, along with the information about images to load.
Introducing this abstraction layer will make migration easier and will preserve functionality for platforms that cannot / don't want to use device tree.
Please have a look at the patches: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2559/1
Regards,
Louis
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Hi Julius,
OK, in that case I can see that a solution based on TF-A's DebugFS
interface might not be desirable. Indeed, our original intention was to
make the whole DebugFS system a debug-only feature (hence its name!). As
such, I agree that it is likely not to get the same level of scrutiny
and testing as other features intended for production systems.
One of the main use cases we have in mind for DebugFS is, being able to
peek and poke into the firmware for testing purposes. Today, when doing
functional testing from the normal world (for example, using TF-A
Tests), we are limited to what's exposed through the SMC interface. And
even then, we have limited visibility on what really happened in the
firmware, as we can only deduce so much from the SMC return value(s).
DebugFS could be used to bridge this gap, by providing a side channel
for getting internal firmware state information.
Going back to the SMC-based solution then, I am not quite convinced
SYSTEM_RESET2 is the right interface for intentionally triggering a
panic in TF-A. I think the semantics do not quite match. If anything, a
firmware crash seems more like a shutdown operation to me rather than a
reset (we don't recover from a firmware crash). I am not even sure we
should look into the PSCI SMC range, as it's not a power-management
operation.
Julius, you wrote:
> It's the same problem that the SMC/PSCI spec and the TF repository layout is only designed to deal with generic vs. SoC-vendor-specific differentiation. If the normal world OS needs a feature, we can only make it generic or duplicate it across all vendors running that OS.
So it sounds like it's not the first time that you hit this issue, is
it? Do you have any other example of Normal World OS feature you would
have liked to expose through a generic SMC interface? I am wondering
whether this could help choosing the right SMC range, if we can identify
some common criteria among a set of such features.
Regards,
Sandrine
Hi,
Thanks George and Lionel for your answers.
Following up and closing on this, the approach used in mentioned patch (https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283) looks ok provided it should now build on all platforms.
The original concern was about api breakage in the generic code, and that there might exist inconsistencies among platforms (ones depending on a 32b offset, others on 64 bits).
Changing the generic seek api offset parameter from ssize_t to signed long long everywhere as a default makes it better compliant to using larger density storage chips in the long term. This is fine as long as it also still support older lower density chips.
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Lionel DEBIEVE via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 08 November 2019 18:34
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] [RFC] BL2 MTD frameworks
Hi,
Just to clarify a little bit more.
There is no link here about a 32/64 bit architecture. The content of
this change is to take care about new memory introduce (mtd devices)
that are not based on size * LBA (where LBA=512) but size * LBA where
(LBA=1) and in such case, the size could exceed the 4GB. It is not
platform dependent and not architecture dependent, it's link to the
connected MTD device only. I'm not sure that a new type is useful except
if you want a type is modified regarding a platform flag such as
USE_LARGE_MTD_DEVICE.
Hope it's more clear.
BR,
Lionel
On 11/5/19 3:20 PM, Gyorgy Szing via TF-A wrote:
> Hi,
>
> I did not investigated all the details so what stays below may contain mistakes, but still I would like to add some comments.
>
> "using a type for the offset"
> The type we use for this purpose seems to be a configuration parameter for the IO layer as it depends on the upper layer being used with the IO library. For example libc uses "long int" to specify the file offset (fseek, ftell), using a different type while running below libc does not seem to be a good idea.
> The best option seems to be to define a type like (as Olivier mentioned) lib/zlib does. How we set this configuration parameter during the build is a question. The offset type could be dictated by the platform, the architecture (aarch32 or aarch64) or by the user. Which one is worth to implement needs investigation.
>
> If it is a good idea to use the same name "off_t" as zlib uses (or even the same type) is be questionable. It may give us more flexibility if we use a dedicated name, and the configuration maps the IO type to the one used by the upper layer.
>
> "32 bit backward compatibility"
> Another angle worth to consider is the 32/64 bit compatibility. I.e.: newlib can use 64 bit offsets even on 32 bit architectures, and they use some wrappers to maintain binary compatibility with old builds. When built in a compatible manner, functions using the standardized names use 32 bit wide offsets and call the real 64 bit implementation as a wrapper.
> To solve compatibility issues we could use a similar pattern. Instead of changing the existing function, we could add a new one (i.e. seek64). Then new 64 bit aware code could use the new function if available, and legacy code could call the old one. Longer term it is an option to deprecate the 32 bit version.
>
> "use stdint.h types"
> And a finally: when selecting the type used for off_t (or whatever we are going to call it) please consider using stdint.h types (i.e. int_fast64_t).
>
> /George
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Olivier Deprez via TF-A
> Sent: 25 October 2019 14:42
> To: tf-a(a)lists.trustedfirmware.org; Lionel DEBIEVE <lionel.debieve(a)st.com>
> Subject: Re: [TF-A] [RFC] BL2 MTD frameworks
>
> Hi Lionel,
>
> On https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283
> I'm extending the discussion to the TF-A ML, to get people's opinion.
>
> The idea is to extend the io_seek offset parameter from ssize_t to unsigned long long.
> There are indeed good reasons for that as flash storage density grows over the years.
>
> Now on the change, the struct io_dev_funcs seek function pointer is generic for the whole codebase / drivers.
> So currently the change breaks the builds for at least rcar, stratix10 (did not check others from that point).
>
> An alternative is defining offset as an off_t type which is ssize_t by default, and only unsigned long long based on the platform (using _FILE_OFFSET_BITS=64). This pattern actually already exists in lib/zlib
>
> Other option is to change the generic prototype for all platform drivers (then we ensure all platforms build and supply platform patches).
>
> What do ML people think?
>
> Regards,
> Olivier.
>
>
>
> ________________________________
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Lionel DEBIEVE via TF-A <tf-a(a)lists.trustedfirmware.org>
> Sent: 18 October 2019 17:26
> To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> Subject: [TF-A] [RFC] BL2 MTD frameworks
>
> Hello Maintainers,
>
> I've sent a patch series around MTD framework management into BL2 stage (cf https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283).
>
> This patch series will add following frameworks:
>
> - a raw NAND framework implementation to support SLC NAND devices. Current implementation is limited to read operations without ECC corrections. Overrides are available to use hardware ECC from controller or low-level drivers. It also supports ONFI detection management but this can also be disabled or overridden by platform specific data.
> - a SPI-MEM framework (inspired from kernel/u-boot implementation) that encapsulates all SPI operations to SPI low level drivers.
> - a SPI-NAND framework based on SPI-MEM to support SPI NAND devices. This framework is also limited to the read operation. It uses single command, address and data bus width as legacy but can be overridden by platform.
> - a SPI-NOR framework based on SPI-MEM to manage SPI NOR devices. It is also limited to read operations using single command, address and data bus width as legacy (override still possible by platform). The framework embeds some specific implementations for manufacturers specific behavior in case of quad mode configuration activation.
>
> This patch series also includes:
>
> - a new io_mtd interface to manage a generic access to all these frameworks.
> - a NAND core driver that accesses independently to raw NAND or SPI-NAND framework. This core driver requires a scratch buffer defined by platform to manage unaligned pages (could be defined to 0 in case of aligned page) and limits access to a single NAND instance management.
> - a complete integration is available based on STM32MP1 platform.
>
> Tests have been performed with the following devices:
>
> SLC NAND:
> - Micron MT29F8G08ABACAH4 (ONFI)
> - Micron MT29F8G16ABACAH4 (ONFI)
> - Toshiba TH58NVG3S0HTAI0 (Non ONFI)
> - Toshiba TC58BVG1S3HTAI0 (On die ECC)
>
> SPI NOR:
> - Macronix MX25L51245G
> - Cypress/Spansion S25FL512
> - Micron n25q512ax3
>
> SPI-NAND:
> - Micron MT29F2G01ABAGD
>
> Waiting for your comments.
>
> Best regards, Lionel
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Hi S*deeps,
Am 10.12.19 um 16:08 schrieb Sudeep Holla via TF-A:
> The more we discuss, I think we will get to know all sorts of CENH(as you put)
> are done all over the place and expecting system is work just fine even
> when lots of interface/contracts are broken is just .....(fill your own word :))
>
> I promise not to discuss these CENH any further after this email :)
>
> On Tue, Dec 10, 2019 at 03:59:01PM +0530, Sandeep Tripathy wrote:
>> Hi Sudeep,
>>
>> On Mon, Dec 9, 2019 at 10:40 PM Sudeep Holla <sudeep.holla(a)arm.com> wrote:
>>>
>>> The application has to terminate cleanly when SIGTERM is sent(may be using
>>> appropriate handler. And can intimate the same to the consumers so that they
>>> can consume the data before it's lost.
>> The DDR is not powered off ever in this scenario. So when to/how to consume
>> the log is up to the (consumer) application design.
>
> CENH#1
>
>> Assume its an incrementing log ie. after reboot this (producer) master again
>> will continue to dump more records on to it.
>
> CENH#2
>
> (I see the roles being exchanged, OS was slave + producer and not sure
> what you are referring has master above. Anyways use KDUMP and features
> like that if you need RAM dump for portions of memory given to the kernel.
Sorry to barge in, but it sounds like you're not quite understanding
each other in this ever-growing thread: Sandeep said his use case was a
SmartNIC, so I assume the logging direction is from SoC on the SmartNIC
to host SoC via PCIe? Think dmesg-like logs, from one host for another -
I fail to see how Sudeep's kdump suggestion could help here.
But maybe I'm not understanding properly, in which case I'll just blame
your abstract master/slave discussions. :)
To me and my ignorance however it sounds like this use case has nothing
really to do with shutdown? If the log producer does not flush their
logs after say each line ending, then also without shutdown you have no
guarantee of the logs reaching the consumer in a timely manner through
all the producer's caches, no? Think of watchdogs, power loss or other
irregular resets that PSCI can do nothing about. Especially for logs,
those error conditions would be the most important to receive data of.
Cheers,
Andreas
>> How would you suggest to handle this. In this case both producer and
>> consumer deliberately asked for coherent memory so why it should also
>> consider a possible data loss due to platforms not giving the coherency
>> because it will add some time to flush the core caches.
>
> CENH#3, not sure if such flexibility should be given to applications.
>
>> If they get non-cached(coherent) memory range they don't have to do anything
>> isn't it ?
>
> Applications must not try that, kernel mostly provides cached memory from
> it's memory allocator. I get a sense that this is some magic pre-allocated
> memory that is either reserved or taken out of kernel memory, but the
> application (along with its driver) maps it coherent in some magic way.
>
> --
> Regards,
> Sudeep
>
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HRB 36809 (AG Nürnberg)
Hi Andre,
Am 09.12.19 um 11:08 schrieb Andre Przywara via TF-A:
> On Mon, 9 Dec 2019 08:41:47 +0100
> Jan Kiszka <jan.kiszka(a)web.de> wrote:
>> How should we continue with the patch below?
>
> If you want to go into the lion's den that is gerrit, please feel free to submit this. Shouldn't be too hard for a single patch. Otherwise I need to look into some RPi4 TF-A stuff this week anyway, so could pick up your patch as well.
[...]
>> Subject: [PATCH] rpi3/4: Add support for offlining CPUs
Seeing the "rpi3/4" here again:
It's been some time since I pitched TF-A to the Foundation for RPi4 in
vein, and my 2.1 based RPi3 test setup broke with some firmware update.
Not seeing any message from Matthias here yet, are you aware that U-Boot
has combined rpi3 and rpi4 targets into one? Are you looking into
combining the PLAT=rpi{3,4} TF-A targets, too? We're targeting to use a
single Linux image for both, so needing two different TF-A binaries
would make TF-A adoption more difficult for us.
Regards,
Andreas
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Hi Sandeep
(I accidentally dropped the TF-A list in my last reply - now re-adding).
> -----Original Message-----
> From: Sandeep Tripathy <sandeep.tripathy(a)broadcom.com>
> Sent: 05 December 2019 17:17
>
> On Thu, Dec 5, 2019 at 9:54 PM Dan Handley <Dan.Handley(a)arm.com> wrote:
> >
> > Hi Sandeep
> >
> > > -----Original Message-----
> > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> > > Sandeep Tripathy via TF-A
> > > Sent: 05 December 2019 12:00
> > >
> > > My query is more on the spec.
> > > The OS (eg: linux) and atf and psci spec seem to have assumed that
> > > it is managing an independent system or managing 'all' the masters
> > > in a coherent domain.
> > > What other
> > > reason could possibly encourage to not to follow a shutdown sequence.
> > >
> > Do you mean "to not follow a *graceful* shutdown sequence"?
> Yes, exactly. Thanks!
> > If so I can think of 3 reasons:
> > 1. It's much slower than a non-graceful shutdown.
> But this is certainly not a concern for smaller embedded systems.
True, but TF-A tries to be a reference for all systems.
> > 2. There is no observable difference between a graceful and non-graceful
> > shutdown from the calling OS's point of view. The OS presumably has no
> > knowledge of other masters it does not manage.
>
> Can CCN state machine go bad because one participating entity just goes off
> without marking its exit ?
> Please note I have not seen the issue and it is my assumption.
>
It depends on the interconnect. Arm interconnects designed for pre-v8.2 systems required explicit programming to take the master our of the coherency domain. Arm interconnects for v8.2+ systems do this automatically via hardware system coherency signals. The TF-A off/reset platform interfaces have provision to do this programming if necessary, but only for the running cluster, which is another reason not to use these PSCI functions in this scenario.
> > 3. It's hard for firmware to implement in the multicore situation.
> Agree. It is complex to initiate and ensure 'other cores' power down in
> firmware.
> >
> > I haven't yet seen a reason why SYSTEM_SUSPEND won't work instead.
> >
> I think you are suggesting to use psci system suspend hook in reboot /power
> off path Or use system suspend from the OS itself ? Should work.
>
I'm suggesting to just do a normal SYSTEM_SUSPEND (suspend to RAM) from the OS.
> @Sudeep, I agree alternate approaches to solve data loss problem works and
> may be those are the best suited.
> The past thread[1] is somewhat related but diverged in multiple directions.
> I wanted to know and focus the above 3 points especially point 2.
Regards
Dan.
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Hi Andre,
I'm trying to get CPU offlining work for Linux on the RPi4. In fact,
this is working already with current ATF master and the Raspberry kernel
4.19.85. Not it would be "nice" if onlining worked as well:
[ 94.959294] CPU1: shutdown
[ 94.959311] psci: CPU1 killed.
[ 106.750960] CPU1: failed to come online
[ 106.755425] CPU1: failed in unknown state : 0x0
Is this a known limitation? Or am I using the wrong kernel (obviously,
it's a downstream one ;) )?
Thanks,
Jan
PS: Current RPi firmware requires an explicit "armstub=armstub8.bin" in
config.txt, no automatic pickup.
Hi Sumit,
Thanks for your answer.
On 12/2/19 2:22 PM, Sumit Garg via TF-A wrote:
> First of all, the authenticated encryption framework for FIP payloads
> allows for algorithm parameter to be passed in the header (see struct
> fip_toc_dec_data here [1]). So it should be easy to add support for
> CCM algorithm too.
>
> Now coming on to additional reason to choose AES-GCM only (apart from
> reasons that you have already mentioned) being:
> - Currently mbedTLS only exposes partial decryption APIs for GCM
> (mbedtls_gcm_starts(), mbedtls_gcm_update() and mbedtls_gcm_finish())
> but not CCM. And we need to rely on stack based partial decryption
> approach (see gcm_decrypt() here [2]) as I think we can't afford large
> buffers for both encrypted and plain firmware image.
>
> [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/2/inclu…
> [2] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2494/2/drive…
I see, that makes sense to me.
>> Also, I am still trying to get my head around how this would integrate
>> with a cryptographic engine where the key does not leave the chip. I can
>> imagine that we could get the address of the encrypted firmware image
>> from the FIP, pass that to a cryptographic engine, request it to decrypt
>> it and store the result somewhere in Trusted RAM. In this case, we
>> wouldn't call plat_get_fip_encryption_key(). Do you have any idea how we
>> would pull this off? Like how the different modules (IO layer, crypto
>> module, image parser module, ...) would integrate together?
>
> In this case, I would expect platform to provide key identifier rather
> than actual key as part of plat_get_fip_encryption_key() which is then
> passed onto auth_decrypt() that is implementation specific to
> cryptographic engine in similar terms as currently done for mbedTLS
> backend.
Ah I see, so plat_get_fip_encryption_key() could return either the key
itself or a key identifier. Just like plat_get_rotpk_info() can return
either the key or a hash of it today. However, in the case of
plat_get_rotpk_info(), it also returns some flags indicating which one
it is. Don't we need something similar for
plat_get_fip_encryption_key()? How will the crypto module be able to
tell the difference between a key and a key ID otherwise? Or would you
expect a given crypto module backend to always use either keys or key
IDs, but not both?
>> I have some concerns around the generation of the initialization vectors
>> in the encrypt_fw tool. Right now, IVs are simply a random sequence of
>> bytes (obtained through a call to OpenSSL's RAND_bytes() API). Now, I
>> would imagine that RAND_bytes() is typically based on a good random
>> number generator and thus will generate different sequences every time
>> it is called. At least, as long as it is called from the same machine
>> every time. But what if we encrypt a new FIP bundle from a different
>> machine, say in the context of a firmware update? Is it not possible
>> that it might choose the same IV out of bad luck?
>>
>> Perhaps that's an issue left to provisioning/manufacturing time and is
>> out of the scope here. But it worries me because AFAIU, the security of
>> AES-GCM is critically undermined if the same nonce is used multiple
>> times with the same key (see section 5.1.1. "Nonce reuse" in RFC 5116).
>> If the encryption key is the SSK (rather than the BSSK) then I guess the
>> probability is even higher, as it is shared amongst a class of devices.
>>
>
> Agree that "nonce" should be unique and using a random number
> generator available on build machine was an effort towards that. But
> thinking about the case that you have mentioned, I think we could have
> an optional user provided "nonce" as an input to "encrypt_fw" tool, so
> that the user is aware to randomly generate and provide a unique
> nonce.
Yes, I like your suggestion of specifying the nonce to the tool. But I
think it should be the default behaviour then. You mention an *optional*
user-provided nonce, I would like to suggest we make this mandatory
instead. We could provide an option to request the tool to generate the
nonce, intended for development purposes.
>> Impact on memory footprint and performance
>> ------------------------------------------
>>
>> Do you know what the performance impact is when this feature is enabled
>> in TF-A, to decrypt images at boot time? Obviously it depends on the
>> platform and whether there is a dedicated cryptographic engine, and I
>> suppose you cannot really get any relevant measurements out of QEMU but
>> I would be interested if you've got any rough numbers.
>
> Following are measurements based on qemu for mbedTLS software library
> based authenticated decryption:
>
> BL31 plain:
> NOTICE: Load image time: 137us, size: 28KB
> BL31 encrypted:
> NOTICE: Load image time: 3979us, size: 28KB
>
> BL32 plain:
> NOTICE: Load image time: 1791us, size: 360KB
> BL32 encrypted:
> NOTICE: Load image time: 36339us, size: 360KB
Thanks. So it's a 29% increase for BL31 and 20% for BL32. I would have
naively expected similar percentages, any idea why we get such a
difference between BL31 and BL32? I am just curious. Maybe it's down to
how the crypto algorithm/mode of operation works under the hood?
> Following is the patch I used to take measurements in case someone is
> interested to try it out on actual platform:
>
> diff --git a/common/bl_common.c b/common/bl_common.c
> index e6f9802..d7303d2 100644
> --- a/common/bl_common.c
> +++ b/common/bl_common.c
> @@ -148,6 +148,7 @@ static int load_auth_image_internal(unsigned int image_id,
> int is_parent_image)
> {
> int rc;
> + unsigned long int ticks;
>
> #if TRUSTED_BOARD_BOOT
> if (dyn_is_auth_disabled() == 0) {
> @@ -164,11 +165,16 @@ static int load_auth_image_internal(unsigned int image_id,
> }
> #endif /* TRUSTED_BOARD_BOOT */
>
> + ticks = read_cntpct_el0();
> /* Load the image */
> rc = load_image(image_id, image_data);
> if (rc != 0) {
> return rc;
> }
> +#define SYS_COUNTER_FREQ_IN_TICKS ((1000 * 1000 * 1000) / 16)
> + NOTICE("Load image time: %ldus, size: %dKB\n",
> + (read_cntpct_el0() - ticks) * 1000000 /
> SYS_COUNTER_FREQ_IN_TICKS,
> + image_data->image_size / 1024);
>
> #if TRUSTED_BOARD_BOOT
> if (dyn_is_auth_disabled() == 0) {
>
>>
>> And what's the memory footprint impact? IIUC, AES-GCM almost does not
>> inflate the size of the data it encrypts. The size of the ciphertext
>> seems to be the same as the plaintext + the size of the authentication
>> tag. So I guess there's no real impact on flash storage and Trusted RAM
>> usage to hold decrypted firmware. But what about the mbedTLS primitives
>> to decrypt the images? How much code and data does this add?
>
> Following is my analysis on code and data increase due to mbedTLS primitives:
>
> Binary size:
> =========
>
> $ ls -lh build/qemu/release/*.bin
> -rwxrwxr-x 1 sumit sumit 58K Dec 2 12:53 build/qemu/release/bl1.bin
> -rwxrwxr-x 1 sumit sumit 66K Dec 2 12:53 build/qemu/release/bl2.bin
> -rwxrwxr-x 1 sumit sumit 29K Dec 2 12:53 build/qemu/release/bl31.bin
> -rw-rw-r-- 1 sumit sumit 2.5M Dec 2 12:53 build/qemu/release/fip.bin
> -rw-rw-r-- 1 sumit sumit 32 Dec 2 12:53 build/qemu/release/rotpk_sha256.bin
>
> After importing mbedTLS primitives to support AES-GCM algo:
>
> $ ls -lh build/qemu/release/*.bin
> -rwxrwxr-x 1 sumit sumit 67K Dec 2 12:56 build/qemu/release/bl1.bin
> -rwxrwxr-x 1 sumit sumit 78K Dec 2 12:56 build/qemu/release/bl2.bin
> -rwxrwxr-x 1 sumit sumit 29K Dec 2 12:56 build/qemu/release/bl31.bin
> -rw-rw-r-- 1 sumit sumit 2.5M Dec 2 12:56 build/qemu/release/fip.bin
> -rw-rw-r-- 1 sumit sumit 32 Dec 2 12:53 build/qemu/release/rotpk_sha256.bin
>
> Stack and heap: Works fine with default allocations on qemu.
> ============
OK thanks.
>> encrypt_fw tool
>> ---------------
>>
>> We have some floating ideas around re-implementing the tools (fiptool,
>> certtool) in a scripting language (possibly python) in the future and
>> also doing a better job at sharing a common description of the list of
>> images to boot/authenticate between the firmware and the host tools. But
>> we're not there yet, so I agree that implementing this new tool in C
>> from the same "mold" as fiptool and certtool is what makes the most
>> sense today. It's just another tool we will have to rework if and when
>> we get there.
>
> Sounds like a good idea to have these tools being python based.
BTW, we noticed some copyright headers attributed to both Arm and Linaro
and pre-dating year 2019, e.g. in
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2496/3/tools…
:
* Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
* Copyright (c) 2019, Linaro Limited
I am guessing this is because this tool was derived from the existing
cert_create tool code, is that right?
>> I did not understand why this new tool needs to know what image it is
>> encrypting. For example, one possible invocation could be:
>>
>> tools/encrypt_fw/encrypt_fw \
>> -k 1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef \
>> --soc-fw bl31.bin \
>> --soc-fw-enc bl31_enc.bin \
>> --tos-fw bl32.bin \
>> --tos-fw-enc bl32_enc.bin
>>
>> Why not invoking the tool once per image instead? As in:
>>
>> encrypt_fw -k key -in ifile -out ofile
>>
>> for BL31, then for BL32? Does the tool do anything different based on
>> the type of image it receives?
>
> "encrypt_fw" tool doesn't infer anything based on image type but image
> types were added for more user visibility and ease of use as follows:
> - Provides the capability to encrypt multiple firmwares on single invocation.
I am not really convinced that this is a useful feature. I would rather
have an external script (or the build system) invoking the tool multiple
times, once per firmware image. Putting that complexity in the tool
itself seems unnecessary to me.
Also, it makes the tool TBBR specific, as it has to know the list of
images it's allowed to encrypt. Unfortunately, we already have this TBBR
knowledge embedded into the fiptool/cert_create tool today but we would
like to change that in the future. It does not scale well with new
images or alternative chains of trust.
> - Restricts usage of tool for FIP payloads only.
Why would we want that?
> - Better align with Makefile framework to build command line args
> while building different images and finally invoke tool at once before
> creating FIP payload.
Could we not invoke the tool for each image as we go along? As in, we
build BL31 and just after we generate the encrypted version of it. Then
we build BL32 and its encrypted version. And so on. While we do that, we
build the fiptool command line that will indeed put all the encrypted
images in the final FIP image. How does that sound?
Regards,
Sandrine
On Thu, Dec 05, 2019 at 10:47:14PM +0530, Sandeep Tripathy wrote:
> On Thu, Dec 5, 2019 at 9:54 PM Dan Handley <Dan.Handley(a)arm.com> wrote:
> >
> > Hi Sandeep
> >
> > > -----Original Message-----
> > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep
> > > Tripathy via TF-A
> > > Sent: 05 December 2019 12:00
> > >
> > > My query is more on the spec.
> > > The OS (eg: linux) and atf and psci spec seem to have assumed that it is
> > > managing an independent system or managing 'all' the masters in a coherent
> > > domain.
> > > What other
> > > reason could possibly encourage to not to follow a shutdown sequence.
> > >
> > Do you mean "to not follow a *graceful* shutdown sequence"?
> Yes, exactly. Thanks!
> If so I can think of 3 reasons:
> > 1. It's much slower than a non-graceful shutdown.
> But this is certainly not a concern for smaller embedded systems.
But we are talking about generic solution here, aren't we ? If so, it
remains concern.
[..]
> I think you are suggesting to use psci system suspend hook in reboot
> /power off path Or use system suspend from the OS itself ? Should work.
>
Just suspend, don't try to use PSCI SYSTEM_SUSPEND in reboot/poweroff
path, not at-least in the generic code. If you think it works fine
to address your issue, you can use it in your custom solution :)
> @Sudeep, I agree alternate approaches to solve data loss problem works
> and may be those are the best suited.
No, the data loss issue had more open questions and I haven't understood
the solution you have there.
> The past thread[1] is somewhat related but diverged in multiple directions.
OK, details again ?
--
Regards,
Sudeep
Hi Julius,
As you were mentioning that the Linux kernel uses /proc/sysrq-trigger
for a similar purpose, I was wondering whether you'd be open to a
solution based on a "DebugFS" entry. As you may have seen on the mailing
list, Olivier posted a proposal for introducing a firmware debug
interface, which has many similarities to how /proc or /sys works in the
kernel world:
https://lists.trustedfirmware.org/pipermail/tf-a/2019-October/000120.html
TF-A patches for this feature are up for review right now and Olivier
has also posted some TF-A Tests patches that demonstrate how this can be
used from normal world. In addition, we are also working on a Linux
driver for this.
As you can imagine, DebugFS uses an SMC interface under the hood
(currently allocated in the SiP range). But being an abstraction over
the SMC layer, which specific SMC function ID is used does not matter so
much and it does not need to be standardized by any Arm specification.
You'd need to mandate all Chrome OS devices to have this DebugFS entry
in the firmware but the backend could vary from platform to platform.
Would that suit your use case?
Regards,
Sandrine
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Hi All,
In TF-A we have a large set of build options (over 90). Dependency and incompatibility checks for these are currently done in the Makefile system. This can be hard to follow and difficult to maintain.
We are investigating if there is a better way to describe the build options in a structured way, handle the dependencies/relations between them, and provide a more user-friendly configuration interface.
A possible good solution for this is Kconfig, more specifically a Python implementation called Kconfiglib [1]. We plan to do more prototyping work in this area.
Any feedback or comments on this topic are welcome.
Regards,
Balint
[1] https://github.com/ulfalizer/Kconfiglib
On Tue, Dec 3, 2019 at 4:58 PM Sandeep Tripathy via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi,
> system shutdown or system reset PSCI calls are invoked by the last
> core in the system. PSCI lib does not do cache flush for the last core
> /cluster and does not follow the core / cluster power down sequence.
> This may cause issue in a system if the system is not standalone one
> ie if the system is a slave or node in a bigger system with other
> coherent masters/PEs.
>
I am not sure if system off/reset is the right API to call in such a setup.
> Please suggest if the PSCI spec expected 'shutdown/reset/reset2' to
> deliberately skip the core/cluster shutdown sequence.
>
Yes and IIRC this has been discussed in the past[1]. I expect to get some
closure on open question on that thread. Quite a few questions were raised
by few people and I am not sure if all were answered. I need to dig but but
AFAIK it wasn't all answered.
--
Regards,
Sudeep
[1] https://lkml.org/lkml/2019/1/18/16
Hi,
In ATF-A, I usually see below code in psci suspend or off code path:
/* Prevent interrupts from spuriously waking up this cpu */
plat_arm_gic_cpuif_disable();
But per my understanding, before calling psci_suspend(), the NW, e.g linux kernel
has disabled all interrupts from cpu level, so here preventing interrupt is
to prevent the interrupts from secure world?
Another question is: for Cortex A55, this is not necessary. Because
CA55 TRM says when the core_pwrdn_en bit is set, executing WFI automatically
masks all interrupts and wake-up events in the core. Am I right?
Thanks in advance
Hi Soby,
Thanks for your response.
>>it is needed to ensure the ordering of the succeeding sev().
Agree. Thanks for the clarification.
>>Was this an issue that actually manifested on a hardware or is this
something that you caught while reviewing the code?
Noticed it while reviewing code and I have not observed it on hardware.
Thanks
-Raghu
On November 26, 2019 at 8:55 AM, Soby Mathew <Soby.Mathew(a)arm.com> wrote:
On 26/11/2019 16:30, Raghupathy Krishnamurthy via TF-A wrote:
Hello!
Reposting this from (https://developer.trustedfirmware.org/T589).
bakery_lock_get() uses a dmbld() after lock acquisition which is insufficient in a lock acquire situation. With just dmbld(), stores in a critical section can be reordered before the dmbld() and indeed before the lock acquisition has taken place. similarly, bakery_lock_release() only uses dmbst(). A load in the critical section could be reordered after the dmbst() and write to the lock data structure releasing the lock. This is likely less of a problem but lock release needs to provide release semantics, and dmbst() is insufficient. For ex: A load in the critical section of CPU1 can be reordered after the store for the lock release, and it could read from a store that is executed on CPU2 in the same critical section, since CPU2 saw the store for the lock release first, and raced into the critical section.
Hi Raghu,
You are right on this. The dmbld() and dmbst() does not provide
sufficient guarantees in the cases you mention.
Was this an issue that actually manifested on a hardware or is this
something that you caught while reviewing the code ?
Also the dsb() after the write to the lock seems unnecessary. Am I missing something here ? It looks like the same issue is present even in bakery_lock_normal.
If you are referring to the dsb() at this line :
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/lib/locks/…
it is needed to ensure the ordering of the succeeding sev().
Best Regards
Soby Mathew
Thanks
Raghu
Hi Sandeep
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep
> Tripathy via TF-A
> Sent: 03 December 2019 16:59
>
> Hi,
> system shutdown or system reset PSCI calls are invoked by the last core in
> the system.
That may be the case in practice but these functions can be called by any core in the system at any time, not just the last core.
> PSCI lib does not do cache flush for the last core /cluster and
> does not follow the core / cluster power down sequence.
Correct. Not only that, it doesn't do anything with the other cores in the system that may be running at that time.
> This may cause issue in a system if the system is not standalone one ie if
> the system is a slave or node in a bigger system with other coherent
> masters/PEs.
>
What issue specifically? Are the other coherent masters expecting to have the same view of the node's memory that the node had prior to calling system off/suspend? If so, then the node is not really independent to the wider system and system off/reset are probably not the right calls to use. Perhaps SYSTEM_SUSPEND is what you're looking for? That function requires all other cores to be off before the call and will perform cache maintenance on the last core.
> Please suggest if the PSCI spec expected 'shutdown/reset/reset2' to
> deliberately skip the core/cluster shutdown sequence.
>
Yes, the spec was deliberately relaxed between version 0.2 and 1.0 to allow implementations to just "pull the plug" since there would be no observable difference to the normal world caller between this behaviour and attempting to shutdown cleanly, which would be difficult and inherently racy anyway.
> Otherwise in case it makes sense following is a patch to take care of this.
> https://review.trustedfirmware.org/#/c/TF-A/trusted-firmware-a/+/2364/
> issue: https://developer.trustedfirmware.org/T566
Thanks but I don't think we want this.
Regards
Dan.
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Hi,
system shutdown or system reset PSCI calls are invoked by the last
core in the system. PSCI lib does not do cache flush for the last core
/cluster and does not follow the core / cluster power down sequence.
This may cause issue in a system if the system is not standalone one
ie if the system is a slave or node in a bigger system with other
coherent masters/PEs.
Please suggest if the PSCI spec expected 'shutdown/reset/reset2' to
deliberately skip the core/cluster shutdown sequence.
Otherwise in case it makes sense following is a patch to take care of this.
https://review.trustedfirmware.org/#/c/TF-A/trusted-firmware-a/+/2364/
issue: https://developer.trustedfirmware.org/T566
Thanks
Sandeep
Hello Sumit,
Sorry for not getting back to you earlier on this. I started looking at
your patches and although I've not completely got my head around them
yet, I've got some early comments and questions. I've tried to classify
them by themes below.
First of all, let me say that I'm no security expert and I did not know
about the concept of authenticated encryption/decryption before looking
at your patches. I spent a couple of hours reading about such algorithms
in general and AES-GCM in particular. Most of what I've learned so far
is based on my understanding of RFC 5116 [1].
What's the motivation for choosing GCM to start with? I've seen that it
is free of patent [2], which I am guessing was a strong argument for it.
I've also read that it is supposed to be quite lightweight and can take
full advantage of parallel processing, although I've not looked into the
details. Were these the reasons? Any other reasons?
Key management
--------------
fip_file_read() retrieves the key from the platform and stores it in a
buffer on the stack. I don't see any code wiping it out of memory once
we're done with it. Did I miss it? Unlike the root of trust public key,
this is a (symmetric) secret key so it is sensitive data that we must
not leave for grabs, even if the stack is in Trusted RAM and that it's
likely to be overwritten by subsequent stack usage.
Also, I am still trying to get my head around how this would integrate
with a cryptographic engine where the key does not leave the chip. I can
imagine that we could get the address of the encrypted firmware image
from the FIP, pass that to a cryptographic engine, request it to decrypt
it and store the result somewhere in Trusted RAM. In this case, we
wouldn't call plat_get_fip_encryption_key(). Do you have any idea how we
would pull this off? Like how the different modules (IO layer, crypto
module, image parser module, ...) would integrate together?
I have some concerns around the generation of the initialization vectors
in the encrypt_fw tool. Right now, IVs are simply a random sequence of
bytes (obtained through a call to OpenSSL's RAND_bytes() API). Now, I
would imagine that RAND_bytes() is typically based on a good random
number generator and thus will generate different sequences every time
it is called. At least, as long as it is called from the same machine
every time. But what if we encrypt a new FIP bundle from a different
machine, say in the context of a firmware update? Is it not possible
that it might choose the same IV out of bad luck?
Perhaps that's an issue left to provisioning/manufacturing time and is
out of the scope here. But it worries me because AFAIU, the security of
AES-GCM is critically undermined if the same nonce is used multiple
times with the same key (see section 5.1.1. "Nonce reuse" in RFC 5116).
If the encryption key is the SSK (rather than the BSSK) then I guess the
probability is even higher, as it is shared amongst a class of devices.
Impact on memory footprint and performance
------------------------------------------
Do you know what the performance impact is when this feature is enabled
in TF-A, to decrypt images at boot time? Obviously it depends on the
platform and whether there is a dedicated cryptographic engine, and I
suppose you cannot really get any relevant measurements out of QEMU but
I would be interested if you've got any rough numbers.
And what's the memory footprint impact? IIUC, AES-GCM almost does not
inflate the size of the data it encrypts. The size of the ciphertext
seems to be the same as the plaintext + the size of the authentication
tag. So I guess there's no real impact on flash storage and Trusted RAM
usage to hold decrypted firmware. But what about the mbedTLS primitives
to decrypt the images? How much code and data does this add?
encrypt_fw tool
---------------
We have some floating ideas around re-implementing the tools (fiptool,
certtool) in a scripting language (possibly python) in the future and
also doing a better job at sharing a common description of the list of
images to boot/authenticate between the firmware and the host tools. But
we're not there yet, so I agree that implementing this new tool in C
from the same "mold" as fiptool and certtool is what makes the most
sense today. It's just another tool we will have to rework if and when
we get there.
I did not understand why this new tool needs to know what image it is
encrypting. For example, one possible invocation could be:
tools/encrypt_fw/encrypt_fw \
-k 1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef \
--soc-fw bl31.bin \
--soc-fw-enc bl31_enc.bin \
--tos-fw bl32.bin \
--tos-fw-enc bl32_enc.bin
Why not invoking the tool once per image instead? As in:
encrypt_fw -k key -in ifile -out ofile
for BL31, then for BL32? Does the tool do anything different based on
the type of image it receives?
Regards,
Sandrine
[1] https://tools.ietf.org/html/rfc5116
[2]
https://csrc.nist.gov/csrc/media/projects/block-cipher-techniques/documents…
Hi All,
The buildsystem of TF-A became complex and loaded with technical debt during the years, and it's time to do something about this.
We made some plans and prototyping work to move to a CMake based solution and we would like to get feedback on the idea.
Why CMake?
In summary CMake is a mature tool having a wide acceptance in C and C++ projects.
Also it has benefits of decreasing fragmentation in the developer community if we sync up with TF-M.
How will it happen?
This will be a slow process where the old build system will co-exist for a period with the new one. How long that period will be is an open question.
For a more detailed summary please see https://developer.trustedfirmware.org/w/tf_a/cmake-buildsystem-proposal/
The design discussion will follow the design review proposal process of TF.org, as described on this page:
https://ci.trustedfirmware.org/job/tf-m-build-test-nightly/lastSuccessfulBu…
You can find the patch for capturing the design decisions and discussion here: https://review.trustedfirmware.org/#/c/TF-A/trusted-firmware-a/+/2662/
If you would like to contribute or have an opinion or any ideas please reply to this email or add a comment on Gerrit (link above).
Regards,
Balint
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On 26/11/2019 16:30, Raghupathy Krishnamurthy via TF-A wrote:
> Hello!
>
> Reposting this from (https://developer.trustedfirmware.org/T589).
>
> bakery_lock_get() uses a dmbld() after lock acquisition which is insufficient in a lock acquire situation. With just dmbld(), stores in a critical section can be reordered before the dmbld() and indeed before the lock acquisition has taken place. similarly, bakery_lock_release() only uses dmbst(). A load in the critical section could be reordered after the dmbst() and write to the lock data structure releasing the lock. This is likely less of a problem but lock release needs to provide release semantics, and dmbst() is insufficient. For ex: A load in the critical section of CPU1 can be reordered after the store for the lock release, and it could read from a store that is executed on CPU2 in the same critical section, since CPU2 saw the store for the lock release first, and raced into the critical section.
Hi Raghu,
You are right on this. The dmbld() and dmbst() does not provide
sufficient guarantees in the cases you mention.
Was this an issue that actually manifested on a hardware or is this
something that you caught while reviewing the code ?
> Also the dsb() after the write to the lock seems unnecessary. Am I missing something here ? It looks like the same issue is present even in bakery_lock_normal.
>
If you are referring to the dsb() at this line :
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/lib/locks/…
it is needed to ensure the ordering of the succeeding sev().
Best Regards
Soby Mathew
> Thanks
> Raghu
>
Hello!
Reposting this from (https://developer.trustedfirmware.org/T589).
bakery_lock_get() uses a dmbld() after lock acquisition which is insufficient in a lock acquire situation. With just dmbld(), stores in a critical section can be reordered before the dmbld() and indeed before the lock acquisition has taken place. similarly, bakery_lock_release() only uses dmbst(). A load in the critical section could be reordered after the dmbst() and write to the lock data structure releasing the lock. This is likely less of a problem but lock release needs to provide release semantics, and dmbst() is insufficient. For ex: A load in the critical section of CPU1 can be reordered after the store for the lock release, and it could read from a store that is executed on CPU2 in the same critical section, since CPU2 saw the store for the lock release first, and raced into the critical section. Also the dsb() after the write to the lock seems unnecessary. Am I missing something here ? It looks like the same issue is present even in bakery_lock_normal.
Thanks
Raghu
Hi all,
I finally got round to collating links to all TF-A public presentations done over the years in our wiki page here
https://developer.trustedfirmware.org/w/tf_a/
I intend to keep the list updated with all future appearances as well.
Let me know if you spot any error or inconsistency.
Thanks
Matteo
Hi everyone,
Please let me introduce the `Property Access Layer` prototype:
The Property Access Layer (PAL) is an abstraction layer for platform specific data, allowing a "property" to be queried and a value retrieved without the requesting entity knowing what backing store is being used to hold the data. It is used to bridge new and old ways of providing platform-specific data:
Today, information like the Chain of Trust is held within several, nested platform-defined tables. In the future, it may be provided as part of a device tree blob, along with the information about images to load.
Introducing this abstraction layer will make migration easier and will preserve functionality for platforms that cannot / don't want to use device tree.
Please have a look at the patches: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2559/1
Regards,
Louis
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Hello,
This message is to provide advance notice that the experimental Secure Partition Manager (SPM) component - based around the SPCI Alpha 1 specification - will be removed from the codebase within the next few weeks. This component was deprecated for the v2.2 release. Normally a component stays in the codebase for one full release cycle after being deprecated but that does not apply to experimental and/or prototype features such as this one.
The intention is not to replace this component directly with a similar SPM component but to instead implement an EL3 SPCI dispatcher component that enables the use of secure partitions with an SPM at either S-EL1 or at S-EL2 (v8.4 or later). This dispatcher would be compliant with the latest public draft of the Secure Partition Client Interface (SPCI) specification at the time.
Please note that the SPM-MM (Management Mode) component is *not* going to be removed as part of this work.
If you have any questions or concerns about this change then please get in touch either via this mailing list or via your Arm partner manager (where applicable).
Thanks,
Paul
Hi,
Just to clarify a little bit more.
There is no link here about a 32/64 bit architecture. The content of
this change is to take care about new memory introduce (mtd devices)
that are not based on size * LBA (where LBA=512) but size * LBA where
(LBA=1) and in such case, the size could exceed the 4GB. It is not
platform dependent and not architecture dependent, it's link to the
connected MTD device only. I'm not sure that a new type is useful except
if you want a type is modified regarding a platform flag such as
USE_LARGE_MTD_DEVICE.
Hope it's more clear.
BR,
Lionel
On 11/5/19 3:20 PM, Gyorgy Szing via TF-A wrote:
> Hi,
>
> I did not investigated all the details so what stays below may contain mistakes, but still I would like to add some comments.
>
> "using a type for the offset"
> The type we use for this purpose seems to be a configuration parameter for the IO layer as it depends on the upper layer being used with the IO library. For example libc uses "long int" to specify the file offset (fseek, ftell), using a different type while running below libc does not seem to be a good idea.
> The best option seems to be to define a type like (as Olivier mentioned) lib/zlib does. How we set this configuration parameter during the build is a question. The offset type could be dictated by the platform, the architecture (aarch32 or aarch64) or by the user. Which one is worth to implement needs investigation.
>
> If it is a good idea to use the same name "off_t" as zlib uses (or even the same type) is be questionable. It may give us more flexibility if we use a dedicated name, and the configuration maps the IO type to the one used by the upper layer.
>
> "32 bit backward compatibility"
> Another angle worth to consider is the 32/64 bit compatibility. I.e.: newlib can use 64 bit offsets even on 32 bit architectures, and they use some wrappers to maintain binary compatibility with old builds. When built in a compatible manner, functions using the standardized names use 32 bit wide offsets and call the real 64 bit implementation as a wrapper.
> To solve compatibility issues we could use a similar pattern. Instead of changing the existing function, we could add a new one (i.e. seek64). Then new 64 bit aware code could use the new function if available, and legacy code could call the old one. Longer term it is an option to deprecate the 32 bit version.
>
> "use stdint.h types"
> And a finally: when selecting the type used for off_t (or whatever we are going to call it) please consider using stdint.h types (i.e. int_fast64_t).
>
> /George
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Olivier Deprez via TF-A
> Sent: 25 October 2019 14:42
> To: tf-a(a)lists.trustedfirmware.org; Lionel DEBIEVE <lionel.debieve(a)st.com>
> Subject: Re: [TF-A] [RFC] BL2 MTD frameworks
>
> Hi Lionel,
>
> On https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283
> I'm extending the discussion to the TF-A ML, to get people's opinion.
>
> The idea is to extend the io_seek offset parameter from ssize_t to unsigned long long.
> There are indeed good reasons for that as flash storage density grows over the years.
>
> Now on the change, the struct io_dev_funcs seek function pointer is generic for the whole codebase / drivers.
> So currently the change breaks the builds for at least rcar, stratix10 (did not check others from that point).
>
> An alternative is defining offset as an off_t type which is ssize_t by default, and only unsigned long long based on the platform (using _FILE_OFFSET_BITS=64). This pattern actually already exists in lib/zlib
>
> Other option is to change the generic prototype for all platform drivers (then we ensure all platforms build and supply platform patches).
>
> What do ML people think?
>
> Regards,
> Olivier.
>
>
>
> ________________________________
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Lionel DEBIEVE via TF-A <tf-a(a)lists.trustedfirmware.org>
> Sent: 18 October 2019 17:26
> To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> Subject: [TF-A] [RFC] BL2 MTD frameworks
>
> Hello Maintainers,
>
> I've sent a patch series around MTD framework management into BL2 stage (cf https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283).
>
> This patch series will add following frameworks:
>
> - a raw NAND framework implementation to support SLC NAND devices. Current implementation is limited to read operations without ECC corrections. Overrides are available to use hardware ECC from controller or low-level drivers. It also supports ONFI detection management but this can also be disabled or overridden by platform specific data.
> - a SPI-MEM framework (inspired from kernel/u-boot implementation) that encapsulates all SPI operations to SPI low level drivers.
> - a SPI-NAND framework based on SPI-MEM to support SPI NAND devices. This framework is also limited to the read operation. It uses single command, address and data bus width as legacy but can be overridden by platform.
> - a SPI-NOR framework based on SPI-MEM to manage SPI NOR devices. It is also limited to read operations using single command, address and data bus width as legacy (override still possible by platform). The framework embeds some specific implementations for manufacturers specific behavior in case of quad mode configuration activation.
>
> This patch series also includes:
>
> - a new io_mtd interface to manage a generic access to all these frameworks.
> - a NAND core driver that accesses independently to raw NAND or SPI-NAND framework. This core driver requires a scratch buffer defined by platform to manage unaligned pages (could be defined to 0 in case of aligned page) and limits access to a single NAND instance management.
> - a complete integration is available based on STM32MP1 platform.
>
> Tests have been performed with the following devices:
>
> SLC NAND:
> - Micron MT29F8G08ABACAH4 (ONFI)
> - Micron MT29F8G16ABACAH4 (ONFI)
> - Toshiba TH58NVG3S0HTAI0 (Non ONFI)
> - Toshiba TC58BVG1S3HTAI0 (On die ECC)
>
> SPI NOR:
> - Macronix MX25L51245G
> - Cypress/Spansion S25FL512
> - Micron n25q512ax3
>
> SPI-NAND:
> - Micron MT29F2G01ABAGD
>
> Waiting for your comments.
>
> Best regards, Lionel
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hello all,
As you may know, the Trusted Board Boot (TBB) code relies on the
platform to define a chain of trust (CoT). Today, the only example of
CoT present in the code base is the one used on Arm platforms, which is
described:
- in the TBBR specification [1].
- in the TF-A documentation [2] [3].
The entire TBBR CoT is built upon the root-of-trust public key (ROTPK),
which is used to authenticate all subsequent firmware binaries and
certificates, either directly or indirectly through some intermediate
certificates.
The TBBR CoT is only one example of a possible certificate chain and key
ownership model. It might not suit all platforms and market segments but
the TBBR implementation in TF-A leaves some freedom for other CoTs.
Today, we are publishing some proof-of-concept code that shows one way
the existing TBBR CoT may be modified in order to detach the BL33 image
from the rest of the CoT. This effectively splits it into 2 CoTs:
- 1 CoT for all secure world images (BL2, BL31, BL32).
- 1 CoT for the normal world bootloader (BL33).
If you are interested, please have a look at the related patch as well
as the companion documentation:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2443https://developer.trustedfirmware.org/w/tf_a/poc-multiple-signing-domains/
Note that at this stage, this is only prototype code and we do not plan
to integrate it in the code base as is, because it does not implement
what we would consider as a clean solution and uses a number of
workarounds. We are considering cleaning this patch up and providing it
as an alternate CoT on FVP platform in the future.
For now, the intent is to provide some material, which we can base a
discussion on. We're hoping to gather feedback from interested parties
on the suitability of this approach.
Regards,
Sandrine
[1]
https://developer.arm.com/docs/den0006/d/trusted-board-boot-requirements-cl…
(see page 21)
[2]
https://trustedfirmware-a.readthedocs.io/en/latest/design/trusted-board-boo…
[3]
https://trustedfirmware-a.readthedocs.io/en/latest/design/auth-framework.ht…
Hi,
I did not investigated all the details so what stays below may contain mistakes, but still I would like to add some comments.
"using a type for the offset"
The type we use for this purpose seems to be a configuration parameter for the IO layer as it depends on the upper layer being used with the IO library. For example libc uses "long int" to specify the file offset (fseek, ftell), using a different type while running below libc does not seem to be a good idea.
The best option seems to be to define a type like (as Olivier mentioned) lib/zlib does. How we set this configuration parameter during the build is a question. The offset type could be dictated by the platform, the architecture (aarch32 or aarch64) or by the user. Which one is worth to implement needs investigation.
If it is a good idea to use the same name "off_t" as zlib uses (or even the same type) is be questionable. It may give us more flexibility if we use a dedicated name, and the configuration maps the IO type to the one used by the upper layer.
"32 bit backward compatibility"
Another angle worth to consider is the 32/64 bit compatibility. I.e.: newlib can use 64 bit offsets even on 32 bit architectures, and they use some wrappers to maintain binary compatibility with old builds. When built in a compatible manner, functions using the standardized names use 32 bit wide offsets and call the real 64 bit implementation as a wrapper.
To solve compatibility issues we could use a similar pattern. Instead of changing the existing function, we could add a new one (i.e. seek64). Then new 64 bit aware code could use the new function if available, and legacy code could call the old one. Longer term it is an option to deprecate the 32 bit version.
"use stdint.h types"
And a finally: when selecting the type used for off_t (or whatever we are going to call it) please consider using stdint.h types (i.e. int_fast64_t).
/George
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Olivier Deprez via TF-A
Sent: 25 October 2019 14:42
To: tf-a(a)lists.trustedfirmware.org; Lionel DEBIEVE <lionel.debieve(a)st.com>
Subject: Re: [TF-A] [RFC] BL2 MTD frameworks
Hi Lionel,
On https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283
I'm extending the discussion to the TF-A ML, to get people's opinion.
The idea is to extend the io_seek offset parameter from ssize_t to unsigned long long.
There are indeed good reasons for that as flash storage density grows over the years.
Now on the change, the struct io_dev_funcs seek function pointer is generic for the whole codebase / drivers.
So currently the change breaks the builds for at least rcar, stratix10 (did not check others from that point).
An alternative is defining offset as an off_t type which is ssize_t by default, and only unsigned long long based on the platform (using _FILE_OFFSET_BITS=64). This pattern actually already exists in lib/zlib
Other option is to change the generic prototype for all platform drivers (then we ensure all platforms build and supply platform patches).
What do ML people think?
Regards,
Olivier.
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Lionel DEBIEVE via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 18 October 2019 17:26
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] [RFC] BL2 MTD frameworks
Hello Maintainers,
I've sent a patch series around MTD framework management into BL2 stage (cf https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283).
This patch series will add following frameworks:
- a raw NAND framework implementation to support SLC NAND devices. Current implementation is limited to read operations without ECC corrections. Overrides are available to use hardware ECC from controller or low-level drivers. It also supports ONFI detection management but this can also be disabled or overridden by platform specific data.
- a SPI-MEM framework (inspired from kernel/u-boot implementation) that encapsulates all SPI operations to SPI low level drivers.
- a SPI-NAND framework based on SPI-MEM to support SPI NAND devices. This framework is also limited to the read operation. It uses single command, address and data bus width as legacy but can be overridden by platform.
- a SPI-NOR framework based on SPI-MEM to manage SPI NOR devices. It is also limited to read operations using single command, address and data bus width as legacy (override still possible by platform). The framework embeds some specific implementations for manufacturers specific behavior in case of quad mode configuration activation.
This patch series also includes:
- a new io_mtd interface to manage a generic access to all these frameworks.
- a NAND core driver that accesses independently to raw NAND or SPI-NAND framework. This core driver requires a scratch buffer defined by platform to manage unaligned pages (could be defined to 0 in case of aligned page) and limits access to a single NAND instance management.
- a complete integration is available based on STM32MP1 platform.
Tests have been performed with the following devices:
SLC NAND:
- Micron MT29F8G08ABACAH4 (ONFI)
- Micron MT29F8G16ABACAH4 (ONFI)
- Toshiba TH58NVG3S0HTAI0 (Non ONFI)
- Toshiba TC58BVG1S3HTAI0 (On die ECC)
SPI NOR:
- Macronix MX25L51245G
- Cypress/Spansion S25FL512
- Micron n25q512ax3
SPI-NAND:
- Micron MT29F2G01ABAGD
Waiting for your comments.
Best regards, Lionel
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Hi all,
We are introducing a new "memory map" tool part of the build system.
The tool parse the blx.map files and print a representation of the memory layout for the latest build.
It can be invoked by adding "memmap" in the make build command.
If you are interested, please have a look at the related patch:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2413/1
Regards,
Louis
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi All,
We are proposing a new firmware debug interface in the form of a "debug filesystem".
The intent is to expose live firmware data or firmware driver HAL to the upper layers, in debug builds.
For people interested, please review and comment the design proposal:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2381
The design is not closed, the intent is to collect opinions, and have a discussion on options and implications.
Thanks & Regards,
Olivier.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Lionel,
On https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283
I'm extending the discussion to the TF-A ML, to get people's opinion.
The idea is to extend the io_seek offset parameter from ssize_t to unsigned long long.
There are indeed good reasons for that as flash storage density grows over the years.
Now on the change, the struct io_dev_funcs seek function pointer is generic for the whole codebase / drivers.
So currently the change breaks the builds for at least rcar, stratix10 (did not check others from that point).
An alternative is defining offset as an off_t type which is ssize_t by default, and only unsigned long long based on the platform (using _FILE_OFFSET_BITS=64). This pattern actually already exists in lib/zlib
Other option is to change the generic prototype for all platform drivers (then we ensure all platforms build and supply platform patches).
What do ML people think?
Regards,
Olivier.
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Lionel DEBIEVE via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 18 October 2019 17:26
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] [RFC] BL2 MTD frameworks
Hello Maintainers,
I've sent a patch series around MTD framework management into BL2 stage (cf https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283).
This patch series will add following frameworks:
- a raw NAND framework implementation to support SLC NAND devices. Current implementation is limited to read operations without ECC corrections. Overrides are available to use hardware ECC from controller or low-level drivers. It also supports ONFI detection management but this can also be disabled or overridden by platform specific data.
- a SPI-MEM framework (inspired from kernel/u-boot implementation) that encapsulates all SPI operations to SPI low level drivers.
- a SPI-NAND framework based on SPI-MEM to support SPI NAND devices. This framework is also limited to the read operation. It uses single command, address and data bus width as legacy but can be overridden by platform.
- a SPI-NOR framework based on SPI-MEM to manage SPI NOR devices. It is also limited to read operations using single command, address and data bus width as legacy (override still possible by platform). The framework embeds some specific implementations for manufacturers specific behavior in case of quad mode configuration activation.
This patch series also includes:
- a new io_mtd interface to manage a generic access to all these frameworks.
- a NAND core driver that accesses independently to raw NAND or SPI-NAND framework. This core driver requires a scratch buffer defined by platform to manage unaligned pages (could be defined to 0 in case of aligned page) and limits access to a single NAND instance management.
- a complete integration is available based on STM32MP1 platform.
Tests have been performed with the following devices:
SLC NAND:
- Micron MT29F8G08ABACAH4 (ONFI)
- Micron MT29F8G16ABACAH4 (ONFI)
- Toshiba TH58NVG3S0HTAI0 (Non ONFI)
- Toshiba TC58BVG1S3HTAI0 (On die ECC)
SPI NOR:
- Macronix MX25L51245G
- Cypress/Spansion S25FL512
- Micron n25q512ax3
SPI-NAND:
- Micron MT29F2G01ABAGD
Waiting for your comments.
Best regards, Lionel
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Hi Feng,
user-guide.rst references GCC 9.1 and later versions. The code was also tested with GCC 10.0.0.
Regards.
Alexei
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Chen Feng via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 24 October 2019 14:32
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] compile toolchain
hi expects,
from the atf2.2 release notes,I can see the tf-a already supported pac bti and mte feature. I want to enable and test it on fvp platform.
I want to know which tool chain to use for compiling code for theses.
Cheers
Feng
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hi expects,
from the atf2.2 release notes,I can see the tf-a already supported pac bti and mte feature. I want to enable and test it on fvp platform.
I want to know which tool chain to use for compiling code for theses.
Cheers
Feng
Hi all,
Trusted Firmware version 2.2 is now available and can be found here:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tag/?h=v2.2
Please refer to the readme and change log for further information.
Thanks & best regards,
[cid:image001.jpg@01D588EA.577B7090]
Bipin Ravi | Principal Design Engineer
Bipin.Ravi(a)arm.com<mailto:Joshua.Sunil@arm.com> | Skype: Bipin.Ravi.ARM
Direct: +1-512-225 -1071 | Mobile: +1-214-212-0794
5707 Southwest Parkway, Suite 100, Austin, TX 78735
Hello Maintainers,
I've sent a patch series around MTD framework management into BL2 stage (cf https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2283).
This patch series will add following frameworks:
- a raw NAND framework implementation to support SLC NAND devices. Current implementation is limited to read operations without ECC corrections. Overrides are available to use hardware ECC from controller or low-level drivers. It also supports ONFI detection management but this can also be disabled or overridden by platform specific data.
- a SPI-MEM framework (inspired from kernel/u-boot implementation) that encapsulates all SPI operations to SPI low level drivers.
- a SPI-NAND framework based on SPI-MEM to support SPI NAND devices. This framework is also limited to the read operation. It uses single command, address and data bus width as legacy but can be overridden by platform.
- a SPI-NOR framework based on SPI-MEM to manage SPI NOR devices. It is also limited to read operations using single command, address and data bus width as legacy (override still possible by platform). The framework embeds some specific implementations for manufacturers specific behavior in case of quad mode configuration activation.
This patch series also includes:
- a new io_mtd interface to manage a generic access to all these frameworks.
- a NAND core driver that accesses independently to raw NAND or SPI-NAND framework. This core driver requires a scratch buffer defined by platform to manage unaligned pages (could be defined to 0 in case of aligned page) and limits access to a single NAND instance management.
- a complete integration is available based on STM32MP1 platform.
Tests have been performed with the following devices:
SLC NAND:
- Micron MT29F8G08ABACAH4 (ONFI)
- Micron MT29F8G16ABACAH4 (ONFI)
- Toshiba TH58NVG3S0HTAI0 (Non ONFI)
- Toshiba TC58BVG1S3HTAI0 (On die ECC)
SPI NOR:
- Macronix MX25L51245G
- Cypress/Spansion S25FL512
- Micron n25q512ax3
SPI-NAND:
- Micron MT29F2G01ABAGD
Waiting for your comments.
Best regards, Lionel
Hi Hugh,
Ccing the Rockchip maintainers from https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tree/docs/maint… as neither appear to be subscribed to this mailing list.
Joanna
On 08/10/2019, 21:45, "TF-A on behalf of Hugh Cole-Baker via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi folks,
I've been using TF-A with mainline U-Boot recently as firmware & boot
loader for a RK3399 Rockpro64 board. I'm compiling TF-A and U-boot based
on this guide [1], using gcc 8.3.0 from Debian.
TF-A v2.1 works fine for this, but I recently tried to switch to TF-A
latest master and found U-Boot gets stuck with this version.
The symptoms are: U-Boot TPL and SPL print starting messages like this:
U-Boot TPL 2019.10-rc4-00037-gdac51e9aaf (Oct 06 2019 - 21:42:50)
Trying to boot from BOOTROM
Returning to boot ROM...
U-Boot SPL 2019.10-rc4-00037-gdac51e9aaf (Oct 06 2019 - 21:42:50 +0000)
Trying to boot from MMC2
...and then there is no more output when normally U-Boot proper would
start, and go on to load the Linux kernel, etc.
Starting from v2.1, with git bisect I found the first 'bad' commit is:
0aad563c7480 rockchip: Update BL31_BASE to 0x40000
and that commit does change some RK3399-related files so seems likely.
I'm not sure how to debug further, any ideas on why boot is hanging
after that change or how to get more debugging information?
Best regards,
Hugh Cole-Baker
[1] https://github.com/u-boot/u-boot/blob/master/doc/README.rockchip
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Hi Varun,
TF-A v1.4 is rather old codebase, can you provide the exact patchset you cherry-picked on top of it?
e.g. you need the Hercules CPU support patch (a4668c36f1fca75b), but possibly also all which is related to HW_ASSISTED_COHERENCY option?
Also, can you pls provide your build cmd line?
Thanks & Regards,
Olivier.
________________________________
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: 11 October 2019 11:21
To: Varun Wadekar <vwadekar(a)nvidia.com>; Joanna Farley <Joanna.Farley(a)arm.com>; Matteo Carlini <Matteo.Carlini(a)arm.com>
Cc: Julius Werner via TF-A <tf-a(a)lists.trustedfirmware.org>; nd <nd(a)arm.com>
Subject: Re: [TF-A] Hercules-AE I$ problems
On 10/10/2019 20:46, Varun Wadekar wrote:
> Hello,
>
> First of all, thanks a lot for posting the Hercules-AE patches.
>
> We picked them up and used them internally. Unfortunately, the CPU sees
> garbage in it's I$ when we enable the I cache for the processor. If we
> keep I$ disabled, TF-A boots properly. We are using TF-A v1.4 for
> verification.
>
> We booted Linux kernel v4.14 on the processor and don't see this problem
> there. So, we suspect something going wrong inside TF-A. Have you seen
> this problem internally? Any hints or clues to solve it would be helpful.
>
> Thanks.
Hi Varun,
As indicated in the commit message of the patch, we have not tested the
CPU support internally due to non-availability of FVP for the CPU.
TF-A assumes that I$ will be invalidated when CPU is reset. Perhaps this
is not true for your setup. Could you try adding a `IC IALLU` in the CPU
reset handler prior to I$ enable and see if that improves anything ?
Best Regards
Soby Mathew
>
>
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Hello,
First of all, thanks a lot for posting the Hercules-AE patches.
We picked them up and used them internally. Unfortunately, the CPU sees garbage in it's I$ when we enable the I cache for the processor. If we keep I$ disabled, TF-A boots properly. We are using TF-A v1.4 for verification.
We booted Linux kernel v4.14 on the processor and don't see this problem there. So, we suspect something going wrong inside TF-A. Have you seen this problem internally? Any hints or clues to solve it would be helpful.
Thanks.
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Hi everyone,
This post is to let you know about some changes to the TrustedFirmware.org website and to the TF-A documentation. It briefly covers what's new, what has moved, and what happens to any existing resources you may be using.
First of all, we are making it more obvious where to access the documentation and the Gerrit review system. The front page of trustedfirmware.org has grown new "Documentation" and "Review" menus with links to this content. Dashboard and Wiki items have moved under the Documentation menu.
Secondly, the online version of the documentation has moved to www.trustedfirmware.org/docs/tf-a<http://www.trustedfirmware.org/docs/tf-a>. This is a pre-rendered, HTML copy of the content that is found under the "docs" directory of the TF-A repository. The content here will remain synchronised with the master branch of the repository. Following the v2.2 release, you will also be able to access a static version of the documentation that corresponds to that tag, via a version selection drop-down menu on the site.
The intention behind this change is to make it easier to find the docs, to improve the output quality and to make the content more modular and readable. The new setup has a persistent table of contents (displayed to the left of the page content) and a search feature, making it easier to find what you're looking for and easier to move between documents and topics.
You may be used to viewing the docs through either the git viewer (https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/about/) or through the Github mirror (https://github.com/ARM-software/arm-trusted-firmware/). The landing pages of these sites now contain links to the new content. While you can still use these sites to access other documentation content, you may find that there are some formatting warnings displayed if you do so.
Finally, if you prefer to read a local copy of the documentation on your machine then you can build the same HTML output following the instructions at https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/docs-bui… (or docs/getting_started/docs-build.rst, for the equivalent file in the repository).
As always, let us know if you have any comments or if there are other changes you would like to see.
Thanks,
Paul
Hi folks,
I've been using TF-A with mainline U-Boot recently as firmware & boot
loader for a RK3399 Rockpro64 board. I'm compiling TF-A and U-boot based
on this guide [1], using gcc 8.3.0 from Debian.
TF-A v2.1 works fine for this, but I recently tried to switch to TF-A
latest master and found U-Boot gets stuck with this version.
The symptoms are: U-Boot TPL and SPL print starting messages like this:
U-Boot TPL 2019.10-rc4-00037-gdac51e9aaf (Oct 06 2019 - 21:42:50)
Trying to boot from BOOTROM
Returning to boot ROM...
U-Boot SPL 2019.10-rc4-00037-gdac51e9aaf (Oct 06 2019 - 21:42:50 +0000)
Trying to boot from MMC2
...and then there is no more output when normally U-Boot proper would
start, and go on to load the Linux kernel, etc.
Starting from v2.1, with git bisect I found the first 'bad' commit is:
0aad563c7480 rockchip: Update BL31_BASE to 0x40000
and that commit does change some RK3399-related files so seems likely.
I'm not sure how to debug further, any ideas on why boot is hanging
after that change or how to get more debugging information?
Best regards,
Hugh Cole-Baker
[1] https://github.com/u-boot/u-boot/blob/master/doc/README.rockchip
Hi,
This is to notify that we are planning to target the Trusted Firmware-A 2.2 release during the third week of October as part of the regular 6 month cadence. The aim is to consolidate all TF-A work since the 2.1 release. As part of this, a release candidate tag will be created and release activities will commence from Monday October 7th. Essentially we will not merge any major enhancements from this date until the release is made. Please ensure any Pull Requests (PR's) desired to make the 2.2 release are submitted in good time to be complete by Friday October 4th. Any major enhancement PR's still open after that date will not be merged until after the release.
Thanks & best regards,
[cid:image001.jpg@01D57244.98C07530]
Bipin Ravi | Principal Design Engineer
Bipin.Ravi(a)arm.com<mailto:Joshua.Sunil@arm.com> | Skype: Bipin.Ravi.ARM
Direct: +1-512-225 -1071 | Mobile: +1-214-212-0794
5707 Southwest Parkway, Suite 100, Austin, TX 78735
Hi,
We are going to configure Coverity Scan Online to make it send
notifications to this mailing list. This way, everyone subscribed on
this mailing list will be aware of newly detected/eliminated defects
found by the tool.
The report will provide a summary of the findings (their nature,
location in the source code). In order to look up the details or to
triage them, you will still need to access the database through the web
portal on
https://scan.coverity.com/projects/arm-software-arm-trusted-firmware .
As a reminder, you will need to create an account to view the defects
there (it's possible to use your Github account).
This is expected to generate a low volume of emails, as we typically do
1 analysis per week day.
As a heads up, the web interface mentions that "an authorization
confirmation will be sent to each newly provided email address and must
be acknowledged before notifications will be sent". In which case,
please ignore these emails.
Regards,
Sandrine
Hi Tristan,
Can you please clarify what your exact concern is? Which files and what text exactly? That will help us answer your concern.
Thanks
Joanna
On 16/09/2019, 23:48, "TF-A on behalf of Tristan Muntsinger via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hello all,
It looks like the copyright guidance on this project changed about a year
ago (Nov 13, 2018) to a placeholder and hasn't been corrected yet. Can
this be fixed to make the license valid so the project can be legally
redistributed per BSD-3 as intended?
Thanks,
Tristan Muntsinger
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Hi Dan,
Whoops, sorry, this fell through the cracks for me since I wasn't on
the to: line. Thanks for your response!
> OK I can see the use of that, although I'd be a bit concerned about such a thing being available as a general service in case it gets used as an attack vector. For example, a test program could aggressively use this service to try to get the firmware to leak secure world information or something about its behaviour.
Yes, of course, we can gate this with a build option so it would only
be available where desired.
> However, I think there might already be support for what you need. PSCI is part of the standard service and the function SYSTEM_RESET2 allows for both architectural and vendor-specific resets. The latter allows for vendor-specific semantics, which could include crashing the firmware as you suggest.
>
> Chrome OS could specify what such a vendor-specific reset looks like and each Chromebook's platform PSCI hooks could be implemented accordingly.
Right, but defining a separate vendor-specific reset type for each
platform is roughly the same as defining a separate SiP SMC for each
of them. It's the same problem that the SMC/PSCI spec and the TF
repository layout is only designed to deal with generic vs.
SoC-vendor-specific differentiation. If the normal world OS needs a
feature, we can only make it generic or duplicate it across all
vendors running that OS.
> Alternatively, this could potentially be defined as an additional architectural reset. This would enable a generic implementation but would require approval/definition by Arm's Architecture team. Like me they might have concerns about this being defined at a generic architectural level.
Yes, I think that would be the best option. Could you kick off that
process with the Architecture team? Or tell me who I should talk to
about this?
Thanks,
Julius
Hello all,
It looks like the copyright guidance on this project changed about a year
ago (Nov 13, 2018) to a placeholder and hasn't been corrected yet. Can
this be fixed to make the license valid so the project can be legally
redistributed per BSD-3 as intended?
Thanks,
Tristan Muntsinger
Hi Yann,
You are quite correct. We will be looking to create a v2.2 tag release sometime early to mid October. You can expect a more formal notification and a request to get any patches submitted in the next week or so. As in previous releases master will be generally locked for a week or so while closedown testing is performed although we will assess incoming patches to see if they can be taken with low risk.
Joanna
On 16/09/2019, 13:19, "TF-A on behalf of Yann GAUTIER via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi,
From the wiki page https://developer.trustedfirmware.org/w/tf_a/tf-a_release_information/, the next v2.2 tag may be released soon.
But the exact timeframe is not yet published.
The wiki page might be updated if you have more information.
When do you expect to release tag v2.2?
What will be the deadline to send patches upstream?
Thanks,
Yann
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Hi,
>From the wiki page https://developer.trustedfirmware.org/w/tf_a/tf-a_release_information/, the next v2.2 tag may be released soon.
But the exact timeframe is not yet published.
The wiki page might be updated if you have more information.
When do you expect to release tag v2.2?
What will be the deadline to send patches upstream?
Thanks,
Yann
Hi Soby,
> Hi Julius,
> Apologize for the radio silence as I was on sabbatical. Yes, I agree the
> project needs to have a clear policy around platforms. We will get this
> started on our end and send a policy proposal for review.
No problem, thanks to Sandrine for taking care of it so quickly.
Unfortunately we now discovered that we're still stuck on the same
issue with MT8173. Could one of you please help getting
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/990/31
landed to fix that too?
Thanks,
Julius
Hello Soby/Joanna,
We would like to upstream support for a new Tegra platform along with some other changes. The last time I checked, there were more than 400 changes waiting to be upstreamed.
Can someone help me with the best/fastest approach to start upstreaming? Previously, we would upstream changes in big chunks (as branches) but I don't know if that approach still works.
Thanks.
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Hi Soby,
> Hmm, if we merge a non-trivial patch and ensure the build works, then we
> do not know whether it runs correctly, whether there are any runtime
> effects that would affect stability/robustness of the platform that even
> might have security implications. Hence, in my view, it is better to
> have a broken build for the platform, rather than have runtime problems.
>
> The project could form a policy that if a platform remains broken for
> more than 2 releases (1 year by current release intervals), then it will
> get removed from the tree after giving enough notifications.
Thanks, yes, I think it would be good to have a clear policy on this,
whatever it is.
I would still like to make a case for keeping these platforms in the
tree on a best-effort basis. You're right that there's a chance for
untested patches to cause all sorts of runtime errors, but I think
that may still be better than a platform that doesn't build at all. A
platform that doesn't build doesn't benefit anyone. A platform that
may have errors still has a chance of working, and even if it doesn't
it gives a third-party contributor or hobby developer who wants to
start using it a chance to fix it up again. This is something we
occasionally see happening with some of our older, less maintained
platforms in coreboot. But if it doesn't even build, the chance of
someone coming along to fix it seem very slim, because then more and
more build issues will keep piling up over time. (In fact, I doubt
there's even any point in keeping broken stuff in the tree for another
year as you proposed... likely all that would do is confuse people who
are trying to refactor project-wide APIs. Code that's never
build-tested just bit rots very quickly. I think at that point you
might as well remove it from the repo immediately.)
It's true that there may also be security issues (which is more
serious), but I'm skeptical that this really makes a lot of
difference. After all, this may happen even while the platform is
still actively maintained. Just testing whether it boots doesn't make
sure you have no security issues anyway. Maybe a way to make this more
visible instead could be to introduce a new
ALLOW_UNMAINTAINED_PLATFORM=1 make variable that the user has to
explicitly set to build a platform without active maintainer? That
could serve as a warning that the code may not be safe to use for
critical applications anymore while still giving developers access to
something if they're willing to deal with possible issues.
Anyway, whatever the policy may be, a more defined process would help.
I think the initial messaging around the console deprecation plan was
fine, but it would have been good to have another explicit
announcement when the CI actually gets turned off for a platform.
Hi Julius,
On 8/27/19 9:55 PM, Julius Werner via TF-A wrote:
> Could either of you please help get the Tegra fix in
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1192
> landed (and subsequently CI for Tegra re-enabled)? It has been
> reviewed and approved for two weeks but nobody is merging it. This is
> blocking more and more work across all coreboot-based platforms so I
> would appreciate if we could get it resolved quickly.
Apologies for the delay. As you may have seen, the patch has now been
merged, and we've also re-enabled the Tegra builds in the CI.
Regards,
Sandrine
Hi Soby, Joanna,
Could either of you please help get the Tegra fix in
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1192
landed (and subsequently CI for Tegra re-enabled)? It has been
reviewed and approved for two weeks but nobody is merging it. This is
blocking more and more work across all coreboot-based platforms so I
would appreciate if we could get it resolved quickly.
Thanks,
Julius
Hi Julius
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Julius
> Werner via TF-A
> Sent: 20 August 2019 02:15
>
> Hi Soby et. al.,
>
> I'd like to implement a small new feature and ask some guidance for how to go
> about it: Chrome OS has the ability to automatically collect crash reports
> from runtime crashes in Trusted Firmware, and we would like to set up
> automated tests to ensure this feature stays working.
> In order to do this we need a way for the non-secure OS to intentionally
> trigger a panic in EL3. The obvious solution would be to implement a new SMC
> for that. (It's common for operating systems to have similar facilities, e.g.
> Linux can force a kernel panic by writing 'c' into /proc/sysrq-trigger.)
>
OK I can see the use of that, although I'd be a bit concerned about such a thing being available as a general service in case it gets used as an attack vector. For example, a test program could aggressively use this service to try to get the firmware to leak secure world information or something about its behaviour.
> My main question is: where should I get an SMC function ID for this?
> This is not a silicon or OEM specific feature, so the SiP Service Calls and
> OEM Service Calls ID ranges seem inappropriate (or do you think it would make
> sense to treat Google or Chrome OS as the "OEM"
> here, even though that's not quite accurate?).
I guess in theory you could mandate that all Chrome OS SiPs provide a specific function ID in their own specific SiP service, but I don't think that's the right solution here...
> There are ranges for Trusted
> Applications and the Trusted OS but unfortunately none for the normal world
> OS.
I don't think the TOS range is right either.
> Is this something that would make sense to allocate under Standard
> Service Calls? Could you just find an ID for me to use there or does
> everything in that range need a big specification document written by Arm?
>
For sure everything in the standard or architectural ranges require specification by Arm, although this does not necessarily need to be big.
However, I think there might already be support for what you need. PSCI is part of the standard service and the function SYSTEM_RESET2 allows for both architectural and vendor-specific resets. The latter allows for vendor-specific semantics, which could include crashing the firmware as you suggest.
Chrome OS could specify what such a vendor-specific reset looks like and each Chromebook's platform PSCI hooks could be implemented accordingly.
Alternatively, this could potentially be defined as an additional architectural reset. This would enable a generic implementation but would require approval/definition by Arm's Architecture team. Like me they might have concerns about this being defined at a generic architectural level.
Regards
Dan.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Soby et. al.,
I'd like to implement a small new feature and ask some guidance for
how to go about it: Chrome OS has the ability to automatically collect
crash reports from runtime crashes in Trusted Firmware, and we would
like to set up automated tests to ensure this feature stays working.
In order to do this we need a way for the non-secure OS to
intentionally trigger a panic in EL3. The obvious solution would be to
implement a new SMC for that. (It's common for operating systems to
have similar facilities, e.g. Linux can force a kernel panic by
writing 'c' into /proc/sysrq-trigger.)
My main question is: where should I get an SMC function ID for this?
This is not a silicon or OEM specific feature, so the SiP Service
Calls and OEM Service Calls ID ranges seem inappropriate (or do you
think it would make sense to treat Google or Chrome OS as the "OEM"
here, even though that's not quite accurate?). There are ranges for
Trusted Applications and the Trusted OS but unfortunately none for the
normal world OS. Is this something that would make sense to allocate
under Standard Service Calls? Could you just find an ID for me to use
there or does everything in that range need a big specification
document written by Arm?
Thanks,
Julius
Hi Marek
The patch is available at
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/1789
Regards.
Alexei
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Joanna Farley via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 19 August 2019 11:41
To: Marek <marek.bykowski(a)gmail.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Advisory TFV 5 to CVE-2017-15031 only saves/stores the PMCR_EL0 across world switching
Hi Marek,
Changes are in review so hopefully soon.
Joanna
On 19/08/2019, 10:56, "TF-A on behalf of Marek via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Dan,
Are there any time estimates when the fix should be in?
Thanks,
Marek
On Sat, 10 Aug 2019 at 22:46, Marek via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Thank you Dan for checking this out. Looking forward into the fix.
>
> Marek
>
> On Thu, 8 Aug 2019 at 17:52, Dan Handley via TF-A
> <tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi Marek
> >
> > Thanks for pointing this out. Typically we expect any timing sensitive secure operations to be implemented at Secure-EL1 or lower, which the current code does protect. However, you are correct that all secure world code including EL3 should not expose timing information. A fix is in progress to address this.
> >
> > Regards
> >
> > Dan.
> >
> > > -----Original Message-----
> > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Marek
> > > Bykowski via TF-A
> > > Sent: 03 August 2019 07:37
> > > To: tf-a(a)lists.trustedfirmware.org; David Cunado <David.Cunado(a)arm.com>
> > > Subject: [TF-A] Advisory TFV 5 to CVE-2017-15031 only saves/stores the
> > > PMCR_EL0 across world switching
> > >
> > > Hi David/ATF Support,
> > >
> > > An excerpt from the commit message to CVE-2017-15031 is "Additionally,
> > > PMCR_EL0 is added to the list of registers that are saved and restored during
> > > a world switch."
> > >
> > > My question is why it is only being saved/restored across the world switch
> > > and not during a "normal" SMC call? When I do modify the
> > > PMCR_EL0 in EL2 or NonSecure-EL1 and run the smc call the PMCCNTR counter
> > > counts during the smc call and does expose secure world timing information to
> > > NonSecure in that matter.
> > >
> > > Thanks,
> > > Marek
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
>
>
> --
> Slán,
> Marek
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
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Marek
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Hi Marek,
Changes are in review so hopefully soon.
Joanna
On 19/08/2019, 10:56, "TF-A on behalf of Marek via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Dan,
Are there any time estimates when the fix should be in?
Thanks,
Marek
On Sat, 10 Aug 2019 at 22:46, Marek via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Thank you Dan for checking this out. Looking forward into the fix.
>
> Marek
>
> On Thu, 8 Aug 2019 at 17:52, Dan Handley via TF-A
> <tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi Marek
> >
> > Thanks for pointing this out. Typically we expect any timing sensitive secure operations to be implemented at Secure-EL1 or lower, which the current code does protect. However, you are correct that all secure world code including EL3 should not expose timing information. A fix is in progress to address this.
> >
> > Regards
> >
> > Dan.
> >
> > > -----Original Message-----
> > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Marek
> > > Bykowski via TF-A
> > > Sent: 03 August 2019 07:37
> > > To: tf-a(a)lists.trustedfirmware.org; David Cunado <David.Cunado(a)arm.com>
> > > Subject: [TF-A] Advisory TFV 5 to CVE-2017-15031 only saves/stores the
> > > PMCR_EL0 across world switching
> > >
> > > Hi David/ATF Support,
> > >
> > > An excerpt from the commit message to CVE-2017-15031 is "Additionally,
> > > PMCR_EL0 is added to the list of registers that are saved and restored during
> > > a world switch."
> > >
> > > My question is why it is only being saved/restored across the world switch
> > > and not during a "normal" SMC call? When I do modify the
> > > PMCR_EL0 in EL2 or NonSecure-EL1 and run the smc call the PMCCNTR counter
> > > counts during the smc call and does expose secure world timing information to
> > > NonSecure in that matter.
> > >
> > > Thanks,
> > > Marek
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
>
>
> --
> Slán,
> Marek
> --
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> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
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Slán,
Marek
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Hi Dan,
Are there any time estimates when the fix should be in?
Thanks,
Marek
On Sat, 10 Aug 2019 at 22:46, Marek via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Thank you Dan for checking this out. Looking forward into the fix.
>
> Marek
>
> On Thu, 8 Aug 2019 at 17:52, Dan Handley via TF-A
> <tf-a(a)lists.trustedfirmware.org> wrote:
> >
> > Hi Marek
> >
> > Thanks for pointing this out. Typically we expect any timing sensitive secure operations to be implemented at Secure-EL1 or lower, which the current code does protect. However, you are correct that all secure world code including EL3 should not expose timing information. A fix is in progress to address this.
> >
> > Regards
> >
> > Dan.
> >
> > > -----Original Message-----
> > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Marek
> > > Bykowski via TF-A
> > > Sent: 03 August 2019 07:37
> > > To: tf-a(a)lists.trustedfirmware.org; David Cunado <David.Cunado(a)arm.com>
> > > Subject: [TF-A] Advisory TFV 5 to CVE-2017-15031 only saves/stores the
> > > PMCR_EL0 across world switching
> > >
> > > Hi David/ATF Support,
> > >
> > > An excerpt from the commit message to CVE-2017-15031 is "Additionally,
> > > PMCR_EL0 is added to the list of registers that are saved and restored during
> > > a world switch."
> > >
> > > My question is why it is only being saved/restored across the world switch
> > > and not during a "normal" SMC call? When I do modify the
> > > PMCR_EL0 in EL2 or NonSecure-EL1 and run the smc call the PMCCNTR counter
> > > counts during the smc call and does expose secure world timing information to
> > > NonSecure in that matter.
> > >
> > > Thanks,
> > > Marek
> > > --
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> > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
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>
>
>
> --
> Slán,
> Marek
> --
> TF-A mailing list
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--
Slán,
Marek
Thank you Dan for checking this out. Looking forward into the fix.
Marek
On Thu, 8 Aug 2019 at 17:52, Dan Handley via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Marek
>
> Thanks for pointing this out. Typically we expect any timing sensitive secure operations to be implemented at Secure-EL1 or lower, which the current code does protect. However, you are correct that all secure world code including EL3 should not expose timing information. A fix is in progress to address this.
>
> Regards
>
> Dan.
>
> > -----Original Message-----
> > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Marek
> > Bykowski via TF-A
> > Sent: 03 August 2019 07:37
> > To: tf-a(a)lists.trustedfirmware.org; David Cunado <David.Cunado(a)arm.com>
> > Subject: [TF-A] Advisory TFV 5 to CVE-2017-15031 only saves/stores the
> > PMCR_EL0 across world switching
> >
> > Hi David/ATF Support,
> >
> > An excerpt from the commit message to CVE-2017-15031 is "Additionally,
> > PMCR_EL0 is added to the list of registers that are saved and restored during
> > a world switch."
> >
> > My question is why it is only being saved/restored across the world switch
> > and not during a "normal" SMC call? When I do modify the
> > PMCR_EL0 in EL2 or NonSecure-EL1 and run the smc call the PMCCNTR counter
> > counts during the smc call and does expose secure world timing information to
> > NonSecure in that matter.
> >
> > Thanks,
> > Marek
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
Slán,
Marek
Hi Marek
Thanks for pointing this out. Typically we expect any timing sensitive secure operations to be implemented at Secure-EL1 or lower, which the current code does protect. However, you are correct that all secure world code including EL3 should not expose timing information. A fix is in progress to address this.
Regards
Dan.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Marek
> Bykowski via TF-A
> Sent: 03 August 2019 07:37
> To: tf-a(a)lists.trustedfirmware.org; David Cunado <David.Cunado(a)arm.com>
> Subject: [TF-A] Advisory TFV 5 to CVE-2017-15031 only saves/stores the
> PMCR_EL0 across world switching
>
> Hi David/ATF Support,
>
> An excerpt from the commit message to CVE-2017-15031 is "Additionally,
> PMCR_EL0 is added to the list of registers that are saved and restored during
> a world switch."
>
> My question is why it is only being saved/restored across the world switch
> and not during a "normal" SMC call? When I do modify the
> PMCR_EL0 in EL2 or NonSecure-EL1 and run the smc call the PMCCNTR counter
> counts during the smc call and does expose secure world timing information to
> NonSecure in that matter.
>
> Thanks,
> Marek
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Soby et. al.,
I wanna kick off a little discussion about how TF-A intends to deal
with in-tree platform ports as they get older and the interest in
maintaining them drops off. Concretely, I noticed that the
plat/nvidia/tegra platforms no longer build since the removal of the
deprecated console API in https://review.trustedfirmware.org/842 last
month. There has been a patch suggestion to fix it uploaded at
https://review.trustedfirmware.org/1192 for two months, but it hasn't
moved forward because it seems that Arm thinks it's on the platform
maintainer (Nvidia) to finish up and test the patch, and they don't
seem to be responding.
This creates a problem for downstream projects like coreboot and
Chrome OS that use Trusted Firmware on Tegra chips and build-test them
in their CI systems. My assumption when setting up the Trusted
Firmware integration for them was that the Trusted Firmware CI would
build test all in-tree platforms for every commit anyway, so we could
always assume that all platforms build on the current master... but
clearly, that assumption broke in this case. (I guess because you
manually overrode the CI in https://review.trustedfirmware.org/842? Or
does it not test all platforms anyway?) So now, coreboot is stuck on
an old TF-A version and cannot move forward for any platform until we
either kick out the Tegra SoCs or get the problem fixed in TF-A (which
is a problem with the testing because I don't have a Tegra board on
hand either).
How do you think we should solve issues like this? Is keeping
platforms that don't build in the tree an intended state? Is there
some deadline after which you intend to remove the platform
completely? Or would it be better to just merge "best effort" commits
like https://review.trustedfirmware.org/1192 that we think should do
the right thing for the platform (and at least makes it build again),
even if nobody is around to test it on real hardware?
To give some experience from the coreboot project, I think it's an
unfortunate truth that SoC vendors just tend to lose interest in
maintaining hardware once it's more than 2-3 years old. At that point
the open-source community has to jump in to continue maintenance, and
they can only do it on a best effort basis. It's not possible to
always find someone with the right hardware and time to test it for
all these old platforms whenever you're trying to do some large,
project wide API change, so eventually you'll just have to accept
patches that haven't been tested for them. Most of the times (if
reviewers pay attention) it works well, sometimes they break. If they
do, eventually someone will notice and then they'll have to bisect and
fix it. I believe Linux is essentially doing the same thing for
lesser-used hardware. It's either that, or you have to constantly kick
out old platforms after a few years. (From the coreboot point of view,
kicking the Tegra platforms out of TF-A would mean we're forced to
remove them from coreboot as well, which would be unfortunate.)
Let me know what you think!
Julius
Hi Julius,
It’s a valid issue you have raised. In general we rely on the platform maintainer to work with us to keep their platform port fresh and in this case we proposed some changes and was looking for feedback from the maintainer. We try in our internal standups at least once a week to look for patch reviews that have had no work on them for 21 days and if we do identify any we start chasing to progress these. Eventually if after several attempts we cannot get the patch to progress we would generally look to abandon if it’s the patch originator we cannot contact. In this case it was the platform maintainer who we needed a review from and you managed to get Varun to notice the patches. If we had not managed to contact them then we would have had to make a call on if to submit the changes or not to at least get the build working even though we would not be able to test them. I would like to think in the case of a broken build we would take that option rather than abandon.
I think this issue is made a little worse in that the CI results are not yet open so not obvious to everybody although hopefully that will be eventually addressed with the proposed Open CI system on trustedfirmware.org where build results will be available. On top of that if partners want to engage in providing a board available that could be integrated into the LAVA farm that’s part of the CI system and would also be tested.
Joanna
On 03/08/2019, 01:10, "TF-A on behalf of Julius Werner via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
> Thanks for the email, Julius. To be clear, we very well intend to be part of the TF-A project. Having said that, I was not aware of the two commits you mentioned in the email and di not know that Tegra builds are broken in the master branch.
Thanks. You were CCed on the patch so I assumed you would've seen it.
If not, maybe your email address isn't set correctly in your Gerrit
account or something? I've already pushed an update to
https://review.trustedfirmware.org/1192 which I think should fix the
issue for Tegra, but I need someone to test it.
Nevertheless, I think it's a good idea to answer these questions in a
general case (e.g. whether we can make sure that we won't break the
build on master even if there are temporary issues with certain
platforms), because it's probably going to become relevant again
sooner or later even if the Tegra issue gets fixed now.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.