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Graduate
May 14, 2025
Question

Processor stuck if I run code without debugger

  • May 14, 2025
  • 5 replies
  • 647 views

Hello.

I have developed an application with touchgfx, lwip, freertos.

I had some problems with lwip (see processor goes to HardFault at __ISB - STMicroelectronics Community, HardFault_Handler when enable LWIP and touchgfx - STMicroelectronics Community).

I understand some causes of HardFault and this morning code seems to work properly.

 

I tried to run the code without debugger but my processor stuck in some point that I can't see because I have no debugger connected.

 

I reconnect debugger, reflash and rerun. After this operations I obtain the problem described in processor goes to HardFault at __ISB - STMicroelectronics Community

 

Why processor run with debugger but it stucks without it ?

 

Thankyou in advance.

 

 

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    5 replies

    Super User
    May 14, 2025

    @MauFanGilaMedical wrote:

    I tried to run the code without debugger but my processor stuck in some point that I can't see because I have no debugger connected.


    Add instrumentation so that you can see where it's hanging; eg,

    • UART output;
    • LEDs; 
    • Pins observable on scope/logic analyser;
    • etc, ...

    LwIP debug output: https://community.st.com/t5/stm32-mcus/using-the-itm-console-for-printf-redirects-and-lwip-debug/ta-p/723472 

     


    @MauFanGilaMedical wrote:

    Why processor run with debugger but it stucks without it ?


    Suggests a timing issue:

    • Debugger adds some start-up delays - so code works;
    • Without debugger, no delays, so something(s) is/are not ready - so doesn't work.

    See: https://community.st.com/t5/stm32-mcus-embedded-software/basic-udp-echo-server-works-in-debug-but-not-run-mode-nucleo/m-p/787083/highlight/true#M61552 

     

    #Instrumentation #CodeInstrumentation #DebugVisibility

    Graduate
    May 14, 2025

    yes, you are right... I'm doing now..thankyou

    Super User
    May 14, 2025

    @MauFanGilaMedical wrote:

    I tried to run the code without debugger but my processor stuck in some point that I can't see because I have no debugger connected.


    Note that you can attach the debugger to an already-running system - so you can see where it is "stuck":

    Disable the Reset:

    AndrewNeil_1-1747229331738.png

    Disable the download:

    AndrewNeil_2-1747229387268.png

    and you don't want it doing a build:

    AndrewNeil_3-1747229428452.png

     

     

    #ConnectToRunningTarget #ConnectToCrashedTarget #ConnectToHungTarget

    Super User
    May 15, 2025

    @MauFanGilaMedical  - I think you're a bit premature in marking my post as the solution: that post just contains some suggestions for how  to debug the issue - it's not actually a solution to the problem.

    See this for how to un-mark a solution.

     

    Take a look at the two posts by @Guillaume K in this thread:

    https://community.st.com/t5/stm32-mcus-embedded-software/stm32f767-lwip-tcp-client/m-p/778561

    do they address your issue?

    In particular, are you getting the mentioned ERR_RTE error?

    Graduate
    May 21, 2025

    No, I don't have RTE error, I commented SCB_InvalidateDCache_by_Addr because it is exceuted even if I have disabled DCache.

     

    Now it works