Yes. Wouldn’t that simplify things?
Adrian
On 24 Jan 2020, at 09:08, Tamas Ban via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>> wrote:
Do you mean to use the ITS API to read/write a monotonous counter in trusted flash?
Tamas
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> On Behalf Of Adrian Shaw via TF-M
Sent: 23 January 2020 13:10
To: Raef Coles <Raef.Coles(a)arm.com<mailto:Raef.Coles@arm.com>>
Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>; Adrian Shaw via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Subject: Re: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Do you mean the transfer of the Protected Storage service? If that is the case, then you don’t need an NV counter API because you can use the ITS API.
Adrian
On 23 Jan 2020, at 08:19, Raef Coles via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>> wrote:
I believe the reason this is being proposed is the transferal of secure storage (as opposed to protected storage) to an application root of trust partition. Such a partition would still require access to the NV counters, at least as far as I know. We ran into this issue while creating the patch to do the transferal, and Jamie suggested this was the most sensible fix.
Raef
________________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> on behalf of Adrian Shaw via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Sent: 22 January 2020 18:38
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>; Minos Galanakis
Cc: nd
Subject: Re: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi Minos,
What are the use cases for Application Root of Trust services that need NV counters?
The NV counters are used by the PSA Root of Trust for rollback protection of images and secure storage. There are usually very few available. Hence the question above.
Adrian
________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> on behalf of Minos Galanakis via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Sent: 22 January 2020 17:28
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org> <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>
Subject: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi,
The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.
This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.
This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.
All input, question or comments are greatly appreciated.
Minos
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.
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.
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Do you mean to use the ITS API to read/write a monotonous counter in trusted flash?
Tamas
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of Adrian Shaw via TF-M
Sent: 23 January 2020 13:10
To: Raef Coles <Raef.Coles(a)arm.com>
Cc: nd <nd(a)arm.com>; Adrian Shaw via TF-M <tf-m(a)lists.trustedfirmware.org>
Subject: Re: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Do you mean the transfer of the Protected Storage service? If that is the case, then you don’t need an NV counter API because you can use the ITS API.
Adrian
On 23 Jan 2020, at 08:19, Raef Coles via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>> wrote:
I believe the reason this is being proposed is the transferal of secure storage (as opposed to protected storage) to an application root of trust partition. Such a partition would still require access to the NV counters, at least as far as I know. We ran into this issue while creating the patch to do the transferal, and Jamie suggested this was the most sensible fix.
Raef
________________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> on behalf of Adrian Shaw via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Sent: 22 January 2020 18:38
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>; Minos Galanakis
Cc: nd
Subject: Re: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi Minos,
What are the use cases for Application Root of Trust services that need NV counters?
The NV counters are used by the PSA Root of Trust for rollback protection of images and secure storage. There are usually very few available. Hence the question above.
Adrian
________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> on behalf of Minos Galanakis via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Sent: 22 January 2020 17:28
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org> <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>
Subject: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi,
The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.
This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.
This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.
All input, question or comments are greatly appreciated.
Minos
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.
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.
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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. 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.
Do you mean the transfer of the Protected Storage service? If that is the case, then you don’t need an NV counter API because you can use the ITS API.
Adrian
On 23 Jan 2020, at 08:19, Raef Coles via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>> wrote:
I believe the reason this is being proposed is the transferal of secure storage (as opposed to protected storage) to an application root of trust partition. Such a partition would still require access to the NV counters, at least as far as I know. We ran into this issue while creating the patch to do the transferal, and Jamie suggested this was the most sensible fix.
Raef
________________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> on behalf of Adrian Shaw via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Sent: 22 January 2020 18:38
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>; Minos Galanakis
Cc: nd
Subject: Re: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi Minos,
What are the use cases for Application Root of Trust services that need NV counters?
The NV counters are used by the PSA Root of Trust for rollback protection of images and secure storage. There are usually very few available. Hence the question above.
Adrian
________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> on behalf of Minos Galanakis via TF-M <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Sent: 22 January 2020 17:28
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org> <tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>>
Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>
Subject: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi,
The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.
This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.
This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.
All input, question or comments are greatly appreciated.
Minos
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.
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.
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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. 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.
I believe the reason this is being proposed is the transferal of secure storage (as opposed to protected storage) to an application root of trust partition. Such a partition would still require access to the NV counters, at least as far as I know. We ran into this issue while creating the patch to do the transferal, and Jamie suggested this was the most sensible fix.
Raef
________________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> on behalf of Adrian Shaw via TF-M <tf-m(a)lists.trustedfirmware.org>
Sent: 22 January 2020 18:38
To: tf-m(a)lists.trustedfirmware.org; Minos Galanakis
Cc: nd
Subject: Re: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi Minos,
What are the use cases for Application Root of Trust services that need NV counters?
The NV counters are used by the PSA Root of Trust for rollback protection of images and secure storage. There are usually very few available. Hence the question above.
Adrian
________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> on behalf of Minos Galanakis via TF-M <tf-m(a)lists.trustedfirmware.org>
Sent: 22 January 2020 17:28
To: tf-m(a)lists.trustedfirmware.org <tf-m(a)lists.trustedfirmware.org>
Cc: nd <nd(a)arm.com>
Subject: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi,
The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.
This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.
This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.
All input, question or comments are greatly appreciated.
Minos
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.
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 Minos,
What are the use cases for Application Root of Trust services that need NV counters?
The NV counters are used by the PSA Root of Trust for rollback protection of images and secure storage. There are usually very few available. Hence the question above.
Adrian
________________________________
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> on behalf of Minos Galanakis via TF-M <tf-m(a)lists.trustedfirmware.org>
Sent: 22 January 2020 17:28
To: tf-m(a)lists.trustedfirmware.org <tf-m(a)lists.trustedfirmware.org>
Cc: nd <nd(a)arm.com>
Subject: [TF-M] [Request For Comments] Expose the NV counters under platform service.
Hi,
The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.
This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.
This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.
All input, question or comments are greatly appreciated.
Minos
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,
The Non-Volatile (NV) counters are a part of the PSA Root of Trust. In order to enable Applications residing in the Root of Trust partition to use the counters, an appropriate interface is needed.
This proposal is to enhance the existing platform service, in order to expose a generic API aimed at providing access to Non-Volatile counters to applications residing in the Application Root of Trust.
This implementation will not modify or affect the existing tfm_plat_nv_counters API or its’ platform specific implementation and will instead introduce a shim layer between a psa_call and the existing logic.
All input, question or comments are greatly appreciated.
Minos
Hi Anton,
I would like to share some details about secure storage in TF-M. I can give an overview of what we have, how to use it and recent/in progress changes, and take questions on more in-depth topics.
Kind regards,
Jamie
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of Anton Komlev via TF-M
Sent: 13 January 2020 11:02
To: TF-M(a)lists.trustedfirmware.org
Cc: nd <nd(a)arm.com>
Subject: Re: [TF-M] TF-M Technical Forum call - January 23
Hello,
Just noted (thanks to David) that January 23 is a day ahead of Lunar New Year so we may expect less interest to the forum from Asia.
This is an opportunity to make the forum time US friendly on the next session.
Preliminary suggest to have it Thursday, January 23rd at 17:00-18:00 UTC. Which a morning time in US.
Again, please send your topics in respond to this mail. Experts and developers could be invited to answer specific questions asked in advance.
Best regards,
Anton Komlev
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> On Behalf Of Anton Komlev via TF-M
Sent: 09 January 2020 11:22
To: TF-M(a)lists.trustedfirmware.org<mailto:TF-M@lists.trustedfirmware.org>
Cc: nd <nd(a)arm.com<mailto:nd@arm.com>>
Subject: [TF-M] TF-M Technical Forum call - January 23
Dear All,
The next session of the Technical Forum is planned in 2 weeks, Thursday, January 23rd at 7:00-8:00 UTC.
Please treat this email and an early invitation for agenda topic collection. Any questions, proposals, concerns are all valid points for our open discussion so do not hesitate to share it.
A big or complicated topics are worth to preliminary discussed over a mailing list.
Best regards,
Anton Komlev
Hi,
As mentioned, we have created the patch here to apply "-fno-builtin":
https://review.trustedfirmware.org/c/trusted-firmware-m/+/3217
Will keep it there for a while for validation purpose. Please help to test this patch if you are run on non-default platforms (those not listed in the platform folder).
Any comment can reply or put comments under the issue:
https://developer.trustedfirmware.org/T653
Thanks.
/Ken
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of Tamas Ban via TF-M
Sent: Thursday, January 9, 2020 4:42 PM
To: tf-m(a)lists.trustedfirmware.org
Subject: Re: [TF-M] [Request For Comments] apply "-fno-builtin" as default compiler flags
Hi Thomas,
Just for my understanding:
* Does IAR provide a C std. lib as part of IAR toolchain package?
* How the std C lib linked to the image? Does user provide an explicit flag which std. C lib to linked to the image?
Tamas
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org<mailto:tf-m-bounces@lists.trustedfirmware.org>> On Behalf Of Thomas Törnblom via TF-M
Sent: 08 January 2020 12:45
To: tf-m(a)lists.trustedfirmware.org<mailto:tf-m@lists.trustedfirmware.org>
Subject: Re: [TF-M] [Request For Comments] apply "-fno-builtin" as default compiler flags
The IAR toolchain does not produce any special "builtin" calls and thus does not have any flag similar to "-fno-builtin".
/Thomas
Den 2020-01-08 kl. 03:53, skrev Ken Liu via TF-M:
Hi,
�
As TF-M needs runtime APIs so we are creating the Secure Partition runtime library, code is ready but we have not forwarded all necessary runtime APIs to the version TF-M implemented, this was caused by the toolchain optimization for built-in APIs, such as:
�
- Forward printf(%s) to puts if there is only one string parameter.
- ARMCLANG would forward memxxx API into an optimized variant.
�
With the '-fno-builtin' flags set in the toolchain, this optimization would be disabled so that user just implement the same name built-in to replace the toolchain version.
�
Please help to check these point before applying '-fno-builtin' and provide your feedback:
�
- Could toolchains out of ARMCLANG and GNUARM have a similar flag?
- Would it affect your project setting and how does it affect?
�
Please help to feedback. I will keep this thread open for ~1 week and let's get a conclusion after this.
�
Thanks!
�
/Ken
--
Thomas T�rnblom, Product Engineer
IAR Systems AB
Box 23051, Strandbodgatan 1
SE-750 23 Uppsala, SWEDEN
Mobile: +46 76 180 17 80 Fax: +46 18 16 78 01
E-mail: thomas.tornblom(a)iar.com<mailto:thomas.tornblom@iar.com> Website: www.iar.com<http://www.iar.com>
Twitter: www.twitter.com/iarsystems<http://www.twitter.com/iarsystems>
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.
> I was referring to the Code Protection between "PSA Root of Trust" and the "Secure Services".
"Secure Services" is not a defined concept in the PSA-FF description of isolation. A "RoT Service" might run in the Application RoT or in the PSA RoT. In the response below I guess that you are referring to a Service that is running in a Secure Partition in the Application RoT?
> From my understanding, in isolation level 2 code of the PSA Root of Trust should be not accessible by Secure Services.
> This creates the practical problem that library code cannot be shared.
>
> Table 5 in PSA-FF describes "Optional Isolation Rules". Is my understanding correct that PSA-FF does not require code execution protection between "PSA Root of Trust" and the "Secure Services".
At level 2 "Application Root of Trust _needs protection from_ PSA Root of Trust" (section 3.1.3)
However, your reading of 3.14 and 3.1.5 is correct:
- Protection of code is not mandatory in an implementation.
- The only mandatory rule when implementing "needs protect from" is in table 4, which in this case requires that PSA RoT "private data" is not accessible to firmware executing in the Application RoT.
So an implementation is permitted to share code (and its RO data) between PSA RoT, Application RoT and even NSPE; or to prevent sharing of code across one or more of those boundaries.
- Andrew
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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Sorry Andrew I was not precise enough. Maybe you can clarify again.
I was referring to the Code Protection between "PSA Root of Trust" and the "Secure Services".
>From my understanding, in isolation level 2 code of the PSA Root of Trust should be not accessible by Secure Services.
This creates the practical problem that library code cannot be shared.
Table 5 in PSA-FF describes "Optional Isolation Rules". Is my understanding correct that PSA-FF does not require code execution protection between "PSA Root of Trust" and the "Secure Services".
Reinhard