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Bastien LS
Graduate
January 19, 2022
Solved

Thread suspension generates a Hard_Fault on STM32U5 with ThreadX

  • January 19, 2022
  • 2 replies
  • 3640 views

I am working on NUCLEO-U575ZI-Q. The code is generated with STM32CubeMX (using STM32CubeIDE) and the application uses ThreadX, which was added to the project using CubeMX.

When a thread call any function that would lead to a suspension of the thread, the function _get_ipsr() (file Middlewares\ST\threadx\ports\cortex_m33\gnu\inc\tx_port.h) is called and it directly triggers a Hard_Fault.

The error would trigger 100% of the time with some source code, and never with some other source code.

I am having this error for a while. I thought I found the solution before, but I was wrong and it was all just luck.

According to this link:

How to debug a HardFault on an ARM Cortex-M MCU | Interrupt (memfault.com)

There is a usage fault with the flag "UNALIGNED" raised. However please note that last time I had trouble with _get_ipsr(), the only flag set to 1 was in the "reserved" field of the usage fault register.

I still working on the issue but I am having trouble finding a solution. Do you have an idea on what could go wrong or how to solve this issue?

    This topic has been closed for replies.
    Best answer by Bastien LS

    So I simplified the threads again and again to make them as close as possible as the examples, until I realized :

    Although the execution of the function _get_ipsr() generates a crash, it is NOT responsible for the crash ; I was being very naive with the debugger.

    The crash actually happens in an other thread, _get_ipsr() is just the last function called from a thread yielding, and leads to an other thread being run.

    I found the source of the crash, could understand and solve the issue.

    Thank you for the help.

    Regards

    2 replies

    H
    Haithem Rahmani
    ST Employee
    January 20, 2022

    Hi @Bastien LS​,

    Are you using the Trust Zone feature or not?

    Did you try the ThreadX application provided within the STM32Cube_FW U5, does the issue appear with any of them?

    regards

    Haithem.

    B
    Bastien LSAuthor
    Graduate
    January 20, 2022

    Hi @Haithem Rahmani​ 

    I am not using the Trust Zone feature.

    I just tried 3 example applications "TX_Thread_Creation", "TX_Thread_MsgQueue", "TX_Thread_Sync" and all of them worked well.

    H
    Haithem Rahmani
    ST Employee
    January 20, 2022

    @Bastien LS​ 

    then could you check what is the difference between your project and the working ones?

    regards

    Haithem.

    T
    TDJ
    Graduate II
    October 19, 2023

    @Bastien LS Did you find the solution? I may be having exactly the same problem on STM32U5A9, no trust - hard faults with UFSR=16 (unaligned), HFSR=0x400000000 (bit 30 set - forced). I cannot find any clear pattern to that. It is not a large code, plenty of SRAM, crash happens inside tx_* functions, e.g. tx_mutex_put(). When I step through it usually does not crash. I start to pull my hair out. MS has a newer version than than the one distributed by CubeMX. It seems it has some fixes.

    TDJ_0-1697756892330.png

     

    T
    TDJ
    Graduate II
    October 19, 2023

    I just found the problem. TX_APP_STACK_SIZE was simply too small.

     
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