Hi Gyorgy, Ken,

Let me add one statement to Gyorgy’s

> It became a de-facto standard and most compilers support it.

Compilers not yet supported can be easily added, if required.

Cheers,

Jonatan

From: TF-M <tf-m-bounces@lists.trustedfirmware.org> On Behalf Of Gyorgy Szing via TF-M
Sent: 27 May 2020 10:45
To: Ken Liu <Ken.Liu@arm.com>; tf-m@lists.trustedfirmware.org
Cc: nd <nd@arm.com>
Subject: Re: [TF-M] [Compiler related] Unify necessary and minimal set compiler definitions for SPM

Hi Ken,

One of the most well working part of CMSIS is the compiler abstraction layer:

• It does wat is needed.
• Most functionality can not be coded in a different way (i.e. intrinsics).
• It became a de-facto standard and most compilers support it.

What are the benefits driving re-implementation?

/George

From: TF-M <tf-m-bounces@lists.trustedfirmware.org> On Behalf Of Ken Liu via TF-M
Sent: 27 May 2020 02:39
To: tf-m@lists.trustedfirmware.org
Cc: nd <nd@arm.com>
Subject: Re: [TF-M] [Compiler related] Unify necessary and minimal set compiler definitions for SPM

Hi Jamie,

At the current stage:

• The CMSIS headers dependency has been moved into HAL, the SPM native code would not rely on specific system provided definitions.
• These usages are quite TF-M specific and small so there is less significance to upstream back, we can revisit if need to do this after extended the header content - but this extending is out of original design expectation.

BR

/Ken

From: Jamie Fox <Jamie.Fox@arm.com>
Sent: Tuesday, May 26, 2020 10:52 PM
To: Ken Liu <Ken.Liu@arm.com>; tf-m@lists.trustedfirmware.org
Cc: nd <nd@arm.com>
Subject: RE: [Compiler related] Unify necessary and minimal set compiler definitions for SPM

Hi Ken,

Many similar abstractions for compiler C language extensions are provided by cmsis_compiler.h, already copied into the TF-M code base. If it does not meet all of our needs, should we consider proposing improvements to the upstream CMSIS project?

Kind regards,

Jamie

From: TF-M <tf-m-bounces@lists.trustedfirmware.org> On Behalf Of Ken Liu via TF-M
Sent: 25 May 2020 05:02
To: tf-m@lists.trustedfirmware.org
Cc: nd <nd@arm.com>
Subject: [TF-M] [Compiler related] Unify necessary and minimal set compiler definitions for SPM

Hi,

We created a proposal to define a minimal set of compiler specific-definitions for SPM. The reason is to avoid many #ifdef inside SPM code.

Only limited definitions are defined. Platform sources need to use platform defined headers for these definitions, such as CMSIS headers.

Special usage such as ‘weak’  or ‘noreturn’ are forbidden inside SPM.

Please put comments for this change:

https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/4211

Or reply here.

This is just an example patch, the follow up would apply this defined headers to all SPM sources.

Thanks

/Ken