Limitation of freeRTOS's stack size from main to maximum ~1480 bytes ?

[ranran]

Hello,

I am trying to overcome some strange issue using IAR when starting freeRTOS thread from main.

I have used the following example for usb

\en.stm32cubeh7\STM32Cube_FW_H7_V1.3.0\Projects\STM32H743I_EVAL\Applications\USB_Host\HID_RTOS

It detects a HID automatically when inserting into board, and display information about it on LCD.

But when I started adding some threads, it suddeny stopped detecting the inserted device.

After some debugging, I've came to conculsion that it is a matter of stack size.

Even if I have only one thread (the usbtest thread) and I give it a large size then it fails:

- osThreadDef(USER_Thread, StartThread, osPriorityNormal, 0,

        128);

+ osThreadDef(USER_Thread, StartThread, osPriorityNormal, 0,

        1480);

I thought that stack size from main is a matter of changing in icf and rebuild :

-define symbol __ICFEDIT_size_cstack__ = 0x400;

+define symbol __ICFEDIT_size_cstack__ = 0x4400;

But surprisingly, it did not help !

Does anyone have any idea ?

Thanks,

ran

[Tesla DeLorean · Accepted solution]

Doesn't it allocate these dynamically from its own heap?​

[Piranha]

Clive is right, it does. Each thread has it's own stack and those are not related to main stack.

[ranran]

Hello,

I am not sure I understand the suggestion how to solve this issue.

Do you mean that I should increase configMINIMAL_STACK_SIZE ? I've tried that.

Please see main here:

int main(void)
{
  MPU_Config();
 
  CPU_CACHE_Enable();
 
  HAL_Init();  
 
  osThreadDef(EthThread, StartEthThread, osPriorityNormal, 0,  configMINIMAL_STACK_SIZE*2 );
  osThreadCreate (osThread(EthThread), NULL);
 
  osThreadDef(rxUART, UART_RxThread, osPriorityNormal, 0, configMINIMAL_STACK_SIZE);
  osThreadCreate (osThread(rxUART), NULL);
 
  osThreadDef(LOGGER, Logger_Thread, osPriorityNormal, 0, configMINIMAL_STACK_SIZE*3 );
  LoggerThreadHandle = osThreadCreate(osThread(LOGGER), NULL);
 
  osKernelStart();
  /* We should never get here as control is now taken by the scheduler */
  for( ;; );
}

Thank you!

ranran

[Piranha]

https://electronics.stackexchange.com/questions/302991/must-freertos-task-stack-size-account-for-interrupt-stack-size

And read the FreeRTOS FAQ link provided there.