Issue with srand() causing exit in STM32H747 Project with FreeRTOS and lwIP

[OskarP]

Hello everyone,

I’m encountering an issue with the srand() function in my STM32H747 project, and I would appreciate your insights on what might be causing this problem.

Hardware:

• MCU: STM32H747IIT6
• Custom board

Software setup:

• CubeMX-generated project
• Cube CLT version: 1.17
• Firmware version: 1.12.1

Problem Description

Whenever I call the srand() function, my code immediately ends up in the exit handler.

To troubleshoot, I created a minimal project with no additional middleware (bare minimum setup), and in that setup, the srand() function works without any issues.

However, in my main project where I need both lwIP and FreeRTOS, calling srand() causes an exit. The project was created following this guide:
How to Create a Project for STM32H7 with Ethernet and lwIP Stack.

I made one modification to the guide: instead of using the default OS wrapper, I selected CMSIS_V2.

Currently, I am only using the M7 core.

What I’ve Tried So Far

• Minimal project without lwIP and FreeRTOS -> srand(12345) works fine.
• Project with lwIP and FreeRTOS -> srand(12345) causes an exit.

I’ve attached an image showing the callstack where the issue occurs. I hope this helps in diagnosing the problem.

Here’s a link to my code: GitHub Repository

Does anyone have any ideas on what might be causing this issue? Could it be related to the use of CMSIS_V2, a conflict with FreeRTOS, or possibly a memory issue?

Thank you in advance for your help!

Best regards,
Oskar

[OskarP]

Do you think it’s possible that this could be a hardware issue since I’m using a custom board? Also, I want to thank you — your input has already been very helpful!

[SofLit]

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@OskarP wrote:

Do you think it’s possible that this could be a hardware issue since I’m using a custom board? 

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I don't think so.. Hardfault is caused by something in the code and not by the hardware.

[OskarP]

I’m currently using CubeIDE 1.17.0. I’ll try it on another PC with a fresh, clean installation of CubeIDE and will get back to you with the results.

[SofLit]

Do you have a ST board: NUCLEO or DISCO so you can have a try?

[OskarP]

So, I tried running the code compiled with a different new installation of CubeIDE 1.17.0, but I’m still encountering the same error.

Unfortunately, I don’t have an official ST board or a second custom board, as this is the first prototype. I will order a Nucleo or Discovery board and give it a try once it arrives.

In the meantime, I’ve added the code from my CubeIDE project. Maybe you can check if it works on your board.

[OskarP]

Off-topic: Do you think the STM32H747I-DISCO is the right option for me, or is there another board that uses the STM32H747 microcontroller you would recommend?

[SofLit]

That depends on what you will do with it. STM32H747I-DISCO is OK but for this test I can recommend NUCLEO-H755  (cheaper than STM32H747I-DISCO).

[SofLit]

But there is no srand() call in the attached project. 

Put srand() in one of USER CODE START/ USER CODE END block, so when you generate the code it will not be removed.

[OskarP]

I ordered the suggested Nucleo board for further testing. I will try to debug the hard fault using the tips provided in this thread: https://community.st.com/t5/stm32-mcus/how-to-debug-a-hardfault-on-an-arm-cortex-m-stm32/ta-p/672235

I have attached the latest code, where I moved the srand() call to USER CODE 2.

Best regards,
OskarP