Hi all,

https://github.com/ARM-software/CMSIS-RTX/releases/tag/v5.9.1 Prebuilt images are in the RTX_Lib.tar.bz2 file.

There were discussions about switching to FreeRTOS, is this still an option?

Dávid

From: Antonio De Angelis via TF-M tf-m@lists.trustedfirmware.org Date: Thursday, 2026. February 26. at 17:22 To: Bohdan.Hunko@infineon.com Bohdan.Hunko@infineon.com, tf-m@lists.trustedfirmware.org tf-m@lists.trustedfirmware.org Cc: nd nd@arm.com Subject: [TF-M] Re: Short enums and short wchar

Hi Bohdan,

Prebuilt RTX libraries were provided by the CMSIS project but I believe that now they have stopped distributing them. Using the prebuilt libraries at the beginning of TF-M was just a practical choice, I’d very much welcome a contribution to build RTX from source as part of the NS code. Do you think you can work towards that? Currently our bandwidth is limited to spend some engineering time on that but would very much appreciate any contributions.

Thanks, Antonio

Sent from Outlook for Mac

From: Bohdan.Hunko--- via TF-M tf-m@lists.trustedfirmware.org Date: Thursday, 26 February 2026 at 15:58 To: tf-m@lists.trustedfirmware.org tf-m@lists.trustedfirmware.org Subject: [TF-M] Short enums and short wchar

Hi all,

Currently TFM specifies -fshort-wchar and -fshort-enums

There previously was a discussion about this in https://lists.trustedfirmware.org/archives/list/tf-m@lists.trustedfirmware.o...

The decision was to remove these flags – which was done in https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/6186 But then fix was reverted in https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/6349 because:

Removing the -fshort-wchar flag will cause link error with RTX library while using armclang and debug mode.

Now we faced same issue when linking some of our prebuilt crypto libraries. Since RTX libraries ware prebuilt by TFM maintainers (prebuilt RTX libs are not part of CMSIS RTX) – I believe it is better to rebuild them without -fshort-wchar and -fshort-enums and remove these flags in TFM. Does TFM team still have a possibility to rebuild these RTX libs? Does this change make sense to TFM community?

Best regards, Bohdan Hunko

Cypress Semiconductor Ukraine LLC Senior Engineer CSS ICW SW INT BFS SFW Mobile: +380995019714 Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com

Let's take this topic to the Tech Forum. Personally, I'd prefer using prebuilt binaries in tf-m-tests and avoiding fetching the CMSIS repo if possible since it's quite heavy. As I recall several RTX binary configurations are needed to cover different compiler options.

Thanks, Anton

From: Nicola Mazzucato via TF-M tf-m@lists.trustedfirmware.org Sent: Thursday, February 26, 2026 5:08 PM To: Antonio De Angelis Antonio.DeAngelis@arm.com; Bohdan.Hunko@infineon.com; tf-m@lists.trustedfirmware.org; David Hazi David.Hazi@arm.com Cc: nd nd@arm.com Subject: [TF-M] Re: Short enums and short wchar

I rebuilt RTX not long ago and was not very difficult. Though I did not change the flags, we my need to look into that.

It's also possible that TF-M could benefit from a more up-to-date version of RTX.

Not sure what others think. Maybe a discussion topic for the next Tech Forum?

Thanks Nick

________________________________ From: David Hazi via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Sent: 26 February 2026 16:24 To: Antonio De Angelis <Antonio.DeAngelis@arm.commailto:Antonio.DeAngelis@arm.com>; Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com <Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com>; tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Cc: nd <nd@arm.commailto:nd@arm.com> Subject: [TF-M] Re: Short enums and short wchar

Hi all,

https://github.com/ARM-software/CMSIS-RTX/releases/tag/v5.9.1 Prebuilt images are in the RTX_Lib.tar.bz2 file.

There were discussions about switching to FreeRTOS, is this still an option?

Dávid

From: Antonio De Angelis via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Date: Thursday, 2026. February 26. at 17:22 To: Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com <Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com>, tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Cc: nd <nd@arm.commailto:nd@arm.com> Subject: [TF-M] Re: Short enums and short wchar Hi Bohdan,

Prebuilt RTX libraries were provided by the CMSIS project but I believe that now they have stopped distributing them. Using the prebuilt libraries at the beginning of TF-M was just a practical choice, I'd very much welcome a contribution to build RTX from source as part of the NS code. Do you think you can work towards that? Currently our bandwidth is limited to spend some engineering time on that but would very much appreciate any contributions.

Thanks, Antonio

Sent from Outlook for Mac From: Bohdan.Hunko--- via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Date: Thursday, 26 February 2026 at 15:58 To: tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Subject: [TF-M] Short enums and short wchar

Hi all,

Currently TFM specifies -fshort-wchar and -fshort-enums

There previously was a discussion about this in https://lists.trustedfirmware.org/archives/list/tf-m@lists.trustedfirmware.o...

The decision was to remove these flags - which was done in https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/6186

But then fix was reverted in https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/6349 because:

Removing the -fshort-wchar flag will cause link error with

RTX library while using armclang and debug mode.

Now we faced same issue when linking some of our prebuilt crypto libraries.

Since RTX libraries ware prebuilt by TFM maintainers (prebuilt RTX libs are not part of CMSIS RTX) - I believe it is better to rebuild them without -fshort-wchar and -fshort-enums and remove these flags in TFM.

Does TFM team still have a possibility to rebuild these RTX libs? Does this change make sense to TFM community?

Best regards,

Bohdan Hunko

Cypress Semiconductor Ukraine LLC

Senior Engineer

CSS ICW SW INT BFS SFW

Mobile: +380995019714 Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com

Hi all,

Thank you for the replies and suggestions.

I investigated the short enum and short wchar settings, and here is what I found.

At the moment, enum and wchar width settings are inconsistent across compilers:

Compiler

short enum

short wchar

ARM

YES

YES

GCC

YES

NO

IAR

NO

NO

CLANG

YES

YES

This inconsistency means that we cant choose uniformed flags for our crypto library.

I checked proposed solutions and I can agree that limited bandwith is also huge limitation for our team, thus we also will not be able to implement solutions like moving to freertos or building CMSIS rtos from sources during TFM build are.

As stated by Nicola:

I rebuilt RTX not long ago and was not very difficult.

I believe this is the best solution here – just rebuild RTOS (with versions that are currently used (v5.5.0 for ARMCLANG and GCC compilers and v5.7.0 for IAR compiler)) with -fno-short-wchar and -fno-short-enums. And then remove short enum/wchar from compiler options in respective toolchain.cmake files in TFM.

If this change is acceptable I would gladly make changes in TFM cmake files and maybe @Nicola Mazzucatomailto:Nicola.Mazzucato@arm.com would be generous to provide rebuilt for the libraries?

Best regards, Bohdan Hunko

Cypress Semiconductor Ukraine LLC Senior Engineer CSS ICW SW INT BFS SFW Mobile: +380995019714 Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com

From: Antonio De Angelis Antonio.DeAngelis@arm.com Sent: Friday, 27 February 2026 11:08 To: Anton Komlev Anton.Komlev@arm.com; Nicola Mazzucato Nicola.Mazzucato@arm.com; Hunko Bohdan (CSS ICW SWE INT BFS SFW) Bohdan.Hunko@infineon.com; tf-m@lists.trustedfirmware.org; David Hazi David.Hazi@arm.com Cc: nd nd@arm.com Subject: Re: Short enums and short wchar

Caution: This e-mail originated outside Infineon Technologies. Please be cautious when sharing information or opening attachments especially from unknown senders. Refer to our intranet guidehttps://intranet-content.infineon.com/explore/aboutinfineon/rules/informationsecurity/ug/SocialEngineering/Pages/SocialEngineeringElements_en.aspx to help you identify Phishing email.

There were mentions of using FreeRTOS, I believe it’s a good option as well, being it a widely adopted solution in the ecosystem. But we can discuss further in a tech forum.

Thanks, Antonio

Sent from Outlook for Mac From: Anton Komlev <Anton.Komlev@arm.commailto:Anton.Komlev@arm.com> Date: Thursday, 26 February 2026 at 20:37 To: Nicola Mazzucato <Nicola.Mazzucato@arm.commailto:Nicola.Mazzucato@arm.com>, Antonio De Angelis <Antonio.DeAngelis@arm.commailto:Antonio.DeAngelis@arm.com>, Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com <Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com>, tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org>, David Hazi <David.Hazi@arm.commailto:David.Hazi@arm.com> Cc: nd <nd@arm.commailto:nd@arm.com> Subject: RE: Short enums and short wchar Let’s take this topic to the Tech Forum. Personally, I’d prefer using prebuilt binaries in tf-m-tests and avoiding fetching the CMSIS repo if possible since it’s quite heavy. As I recall several RTX binary configurations are needed to cover different compiler options.

Thanks, Anton

From: Nicola Mazzucato via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Sent: Thursday, February 26, 2026 5:08 PM To: Antonio De Angelis <Antonio.DeAngelis@arm.commailto:Antonio.DeAngelis@arm.com>; Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com; tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org; David Hazi <David.Hazi@arm.commailto:David.Hazi@arm.com> Cc: nd <nd@arm.commailto:nd@arm.com> Subject: [TF-M] Re: Short enums and short wchar

I rebuilt RTX not long ago and was not very difficult. Though I did not change the flags, we my need to look into that.

It's also possible that TF-M could benefit from a more up-to-date version of RTX.

Not sure what others think. Maybe a discussion topic for the next Tech Forum?

Thanks Nick

________________________________ From: David Hazi via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Sent: 26 February 2026 16:24 To: Antonio De Angelis <Antonio.DeAngelis@arm.commailto:Antonio.DeAngelis@arm.com>; Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com <Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com>; tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Cc: nd <nd@arm.commailto:nd@arm.com> Subject: [TF-M] Re: Short enums and short wchar

Hi all,

https://github.com/ARM-software/CMSIS-RTX/releases/tag/v5.9.1 Prebuilt images are in the RTX_Lib.tar.bz2 file.

There were discussions about switching to FreeRTOS, is this still an option?

Dávid

From: Antonio De Angelis via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Date: Thursday, 2026. February 26. at 17:22 To: Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com <Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com>, tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Cc: nd <nd@arm.commailto:nd@arm.com> Subject: [TF-M] Re: Short enums and short wchar Hi Bohdan,

Prebuilt RTX libraries were provided by the CMSIS project but I believe that now they have stopped distributing them. Using the prebuilt libraries at the beginning of TF-M was just a practical choice, I’d very much welcome a contribution to build RTX from source as part of the NS code. Do you think you can work towards that? Currently our bandwidth is limited to spend some engineering time on that but would very much appreciate any contributions.

Thanks, Antonio

Sent from Outlook for Mac From: Bohdan.Hunko--- via TF-M <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Date: Thursday, 26 February 2026 at 15:58 To: tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org <tf-m@lists.trustedfirmware.orgmailto:tf-m@lists.trustedfirmware.org> Subject: [TF-M] Short enums and short wchar

Hi all,

Currently TFM specifies -fshort-wchar and -fshort-enums

There previously was a discussion about this in https://lists.trustedfirmware.org/archives/list/tf-m@lists.trustedfirmware.o...

The decision was to remove these flags – which was done in https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/6186

But then fix was reverted in https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/6349 because:

Removing the -fshort-wchar flag will cause link error with

RTX library while using armclang and debug mode.

Now we faced same issue when linking some of our prebuilt crypto libraries.

Since RTX libraries ware prebuilt by TFM maintainers (prebuilt RTX libs are not part of CMSIS RTX) – I believe it is better to rebuild them without -fshort-wchar and -fshort-enums and remove these flags in TFM.

Does TFM team still have a possibility to rebuild these RTX libs? Does this change make sense to TFM community?

Best regards,

Bohdan Hunko

Cypress Semiconductor Ukraine LLC

Senior Engineer

CSS ICW SW INT BFS SFW

Mobile: +380995019714 Bohdan.Hunko@infineon.commailto:Bohdan.Hunko@infineon.com