Processor stuck if I run code without debugger

[MauFanGilaMedical]

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.

[Andrew Neil · Accepted solution]

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@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.

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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 

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@MauFanGilaMedical wrote:

Why processor run with debugger but it stucks without it ?

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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 

[MauFanGilaMedical]

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

[Andrew Neil]

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@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.

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

Disable the Reset:

Disable the download:

and you don't want it doing a build: