[stenslae]

Description

When WOLFSSL_CMSIS_RTOS or WOLFSSL_CMSIS_RTOSv2 is built with GCC and without WOLFSSL_MDK_ARM, types.h falls through to its generic threading branch. That branch defines WOLFSSL_THREAD as the MSVC-only __stdcall, so any file that includes types.h fails to compile. MBED is also affected, because settings.h sets WOLFSSL_CMSIS_RTOS for it.

• added a CMSIS-RTOS branch with the same THREAD_RETURN/THREAD_TYPE as the generic branch, but with an empty WOLFSSL_THREAD. WOLFSSL_MDK_ARM builds still use their existing branch.
• a host-only reproducer that uses stub cmsis_os.h/cmsis_os2.h and compiles with gcc explicitly, since clang accepts __stdcall and would pass without the fix.
• runs the reproducer on ubuntu-24.04.

Testing

• The reproducer passes for v1 and v2 with the fix and fails for both against the old types.h.
• Full library cross-compile with arm-none-eabi-gcc -mcpu=cortex-m4 and the real CMSIS headers from STM32Cube F4 1.28.0, building all 129 sources.

Known limitation (pre-existing, follow-up PR): a GCC build against a pure CMSIS-RTOS v1.x header (osCMSIS < 0x20000) now gets past types.h but then fails in src/internal.c at LowResTimer(). That function calls the v2-only osKernelGetTickCount(). v1-compat headers built on RTOS2, such as Keil RTX5 and STM32Cube FreeRTOS CMSIS_RTOS_V2, are not affected.

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[Copilot]

🟢 Approval recommended

There are no active review issues blocking the CMSIS threading compatibility change.

No open issues 🎉

What changed in this PR

Fixes GCC compilation for CMSIS-RTOS v1/v2 configurations without WOLFSSL_MDK_ARM by avoiding __stdcall in wolfSSL’s thread definitions.

Changes:

• Adds a CMSIS-specific threading branch while preserving existing MDK ARM behavior.
• Adds a host-only GCC regression test with minimal CMSIS header stubs.
• Packages the test files and runs the reproducer in Ubuntu 24.04 CI.

File	Description
wolfssl/​wolfcrypt/​types.h	Defines CMSIS thread types with an empty calling-convention macro.
tests/​include.am	Includes regression test files in source distributions.
tests/​cmsis-rtos-thread-types-repro/​user_settings.h	Provides minimal multithreaded test settings.
tests/​cmsis-rtos-thread-types-repro/​run.sh	Compiles both CMSIS variants explicitly with GCC.
tests/​cmsis-rtos-thread-types-repro/​repro.c	Exercises thread callback declarations and assignment.
tests/​cmsis-rtos-thread-types-repro/​cmsis_os2.h	Supplies minimal CMSIS-RTOS v2 type stubs.
tests/​cmsis-rtos-thread-types-repro/​cmsis_os.h	Supplies minimal CMSIS-RTOS v1 type stubs.
.github/​workflows/​cmsis-rtos-thread-types.yml	Runs the regression test on Ubuntu 24.04.

_{Review effort: Balanced}

[github-actions]

MemBrowse Memory Report · Explore what changed →

zephyr-frdm_rw612

• FLASH: datas +16 B, log_const_area -8 B, rodata +36 B, text +10,544 B (+3.7%, 293,052 B / 67,108,864 B, total: 0% used)
• RAM: bss +49 B, datas +16 B (+0.1%, 58,423 B / 983,040 B, total: 6% used)

No memory changes detected for:

• gcc-arm-cortex-m0plus
• gcc-arm-cortex-m3
• gcc-arm-cortex-m4
• gcc-arm-cortex-m4-baremetal
• gcc-arm-cortex-m4-crypto-only
• gcc-arm-cortex-m4-dtls13
• gcc-arm-cortex-m4-min-ecc
• gcc-arm-cortex-m4-openssl-compat
• gcc-arm-cortex-m4-pkcs7
• gcc-arm-cortex-m4-pq
• gcc-arm-cortex-m4-rsa-only
• gcc-arm-cortex-m4-sp-math
• gcc-arm-cortex-m4-tls12
• gcc-arm-cortex-m4-tls13
• gcc-arm-cortex-m7
• gcc-arm-cortex-m7-pq
• gcc-arm-cortex-m7-tls13
• stm32-sim-stm32h753

---

_{Catch memory regressions in CI with MemBrowse. Free for open source.}

[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #12099

Scan targets checked: wolfcrypt-src, wolfcrypt-bugs, wolfssl-src, wolfssl-bugs
Not reviewed (no scan target covers them): .github/workflows/cmsis-rtos-thread-types.yml, tests/cmsis-rtos-thread-types-repro/cmsis_os.h, tests/cmsis-rtos-thread-types-repro/cmsis_os2.h, tests/cmsis-rtos-thread-types-repro/run.sh, tests/cmsis-rtos-thread-types-repro/user_settings.h, tests/include.am
Coverage: 2 of 2 in-scope changed file(s) opened by the reviewer

Fenrir result: Approved ✅

No new issues found in the changed files.

Advisory only — this automated result does not count as a GitHub approval.

Review tier: Max