tx_port.h inline assembly "operand syntax error" on IAR include

[karlyt]

Describe the bug
line 585 of txport.h raises an error message 'operand syntax error' while building the code in IAR.

• target device: cortex-m33
• Which version of Eclipse ThreadX? commit b91b03b
• What toolchain and environment? IAR for arm 9.50.3
• What have you tried to diagnose or workaround this issue? use __DSB() and __ISB() to replace the code

[fdesbiens]

Hi @karlyt.

Thank you for this report. I will look into it.

[Corderbollie]

Same problem here
Commit: 44d7c95
Target: Cortex-M7
Toolchain: IAR EWARM 9.70.4
Error in tx_port.h line 590

I fixed it temporarily from
_asm__ volatile ("dsb 0xF \n isb 0xF " : : : "memory");
to
_asm__ volatile ("dsb sy \n isb sy " : : : "memory");

[edalab-xrg]

I fixed it temporarily from
asm_ volatile ("dsb 0xF \n isb 0xF " : : : "memory");
to
asm_ volatile ("dsb #0xF \n isb #0xF" : : : "memory"); or asm_ volatile ("dsb sy \n isb sy " : : : "memory");

[rsherrywork]

Also confirming this on:
Commit: 44d7c95
Target: Cortex-M33
Toolchain: IAR EWARM 9.70.4
Error in ports/cortex_m33/tx_port.h line 585

The _asm__ volatile ("dsb sy \n isb sy " : : : "memory"); works 👍

Alternatively, if you can tolerate the function call overhead around critical sections, or need MISRA compliance anyway, simply add TX_DISABLE_INLINE to your commandline args or #define TX_DISABLE_INLINE in your tx_user.h if you use the TX_INCLUDE_USER_DEFINE_FILE mechanism.

[fdesbiens]

Hi @karlyt, @Corderbollie, @edalab-xrg and @rsherrywork.

Thank you all for the reports and for converging on the same workaround — that made this easy to confirm.

The bug is real. _tx_thread_system_return_inline() in the Cortex-M tx_port.h headers issues its barriers as dsb 0xF and isb 0xF. A bare hexadecimal barrier operand is a GNU assembler extension. IAR's inline assembler accepts only the architectural option names, so it rejects the line outright and the header cannot be included at all. The block is guarded for GCC, armclang and IAR together, so every IAR user of an affected port hits this the moment inlining is left enabled.

I have opened #729, which replaces both operands with sy. That is the Arm UAL name for the full system domain and the exact value 0xF encodes, so the generated instruction is unchanged and only the spelling differs. It is the canonical form in the Arm Architecture Reference Manual and is accepted by GNU as, armclang and IAR alike, which is exactly why your workarounds all work.

The fix covers the two ports_arch master headers and all thirty-two generated or hand-maintained copies under ports, spanning the Cortex-M0, M23, M3, M33, M4, M52, M55, M7 and M85 families across the ac5, ac6, gnu, iar and keil toolchains. I also updated the probe in scripts/check_ports.sh that looked for the old spelling.

@rsherrywork, your TX_DISABLE_INLINE suggestion is a good stopgap for anyone who cannot patch locally, and it is worth noting it costs a function call per critical section, so I would not leave it in place once the fix lands.

I will close this once the pull request is merged.