ARM Cortex-M3 crashed with --use_frame_pointer

Kernel
1

bettermanlu wrote on Friday, December 11, 2015:

Our current project includes FreeRTOS, and I added --use_frame_pointer to Keil uVision’s ARMGCC compiler option. But after loading firmware into STM32F104 chip, then runs it, it crashed. Without --use_frame_pointer, everything is OK. The hard fault handler shows that faultStackAddress is 0x40FFFFDC, which points to a reserved area. Does anyone has any idea of this error? Thanks a lot.


__asm void HardFault_Handler(void)
{
   TST lr, #4
   ITE EQ
   MRSEQ r0, MSP
   MRSNE r0, PSP
   B __cpp(Hard_Fault_Handler)
}
void Hard_Fault_Handler(uint32_t *faultStackAddress)
{

}

I stepped into each line of code, and the crash happened in below function in FreeRTOS’s port.c after I called vTaskDelete(NULL);

void vPortYieldFromISR( void )
{
    /* Set a PendSV to request a context switch. */
    portNVIC_INT_CTRL_REG = portNVIC_PENDSVSET_BIT;
}

But seems like this is not the root cause, because when I deleted vTaskDelete(NULL), crash still happened.

2

rtel wrote on Friday, December 11, 2015:

I’m afraid without reading the compiler documentation, or inspecting the changes to the generated assembler code, I don’t know why this would be. The code assumes the compiler generates ARM EABI compliant code, maybe using the frame pointer changes that? Why do you need that compiler option?

3

bettermanlu wrote on Monday, December 14, 2015:

We’d like to unwind ARM Cortex M3 stack when crash happened, so we need to save FP(Frame Pointer) to the stack. That’s why we add --use_frame_pointer to Keil uVision’s ARMGCC compiler option.

4

bettermanlu wrote on Wednesday, January 13, 2016:

I found that if I comment out the xTimerCreateTimerTask() in vTaskStartScheduler() function, the crash does not happen. Any thoughts? Thanks.

5

bettermanlu wrote on Wednesday, January 13, 2016:

My test code for your reference:


#include "FreeRTOSConfig.h"
#include "FreeRTOS.h"
#include "task.h"
#include <stm32f10x.h>


void crashTask(void *param)
{

    unsigned int i = 0;
    /* halt the hardware. */
    while(1)
    {
         i += 1;
    }
    vTaskDelete(NULL);
}
void testCrashTask()
{
    xTaskCreate(crashTask, (const signed char *)"crashTask",  configMINIMAL_STACK_SIZE,  NULL,  1,  NULL);    
}

void Hard_Fault_Handler(unsigned int *faultStackAddress);

/* The fault handler implementation calls a function called Hard_Fault_Handler(). */
#if defined(__CC_ARM)
__asm void HardFault_Handler(void)
{
   TST lr, #4
   ITE EQ
   MRSEQ r0, MSP
   MRSNE r0, PSP
   B __cpp(Hard_Fault_Handler)
}
#else
void HardFault_Handler(void)
{
   __asm("TST lr, #4");
   __asm("ITE EQ");
   __asm("MRSEQ r0, MSP");
   __asm("MRSNE r0, PSP");
   __asm("B Hard_Fault_Handler");
}
#endif

void Hard_Fault_Handler(unsigned int *faultStackAddress)
{
    int i = 0;
    while(1)
    {
        i += 1;
    }
}

void nvicInit(void)
{

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);
	#ifdef  VECT_TAB_RAM  							
	NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);  	
	#else
	NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);  
	#endif
}



int main()
{
    nvicInit();

    testCrashTask();
    vTaskStartScheduler();
    
}

/* For now, the stack depth of IDLE has 88 left. if want add func to here, 
   you should increase it. */
void vApplicationIdleHook(void)
{	/* ATTENTION: all funcs called within here, must not be blocked */
	//workerProbe();
}

void debugSendTraceInfo(unsigned int taskNbr)
{
}
6

rtel wrote on Wednesday, January 13, 2016:

The timer task is a standard task, written in C, so there is nothing special about it that I am aware of. It does however give a big clue as to where you could focus your debugging. See how far you get through the function - it is actually quite small.

7

bettermanlu wrote on Thursday, January 14, 2016:

Seems like SP is corrupted.

Another odd thing is that if I debug it and step into the TimerTask’s portYIELD_WITHIN_API() function call, then resume the application. It does not crash. So my guess is that this might due to certain time sequence. But I could not find the root cause of it.

Any thoughts? Thanks.