定位Fault方法

定位ARM Hard Fault 的方法

1，用Keil的话，可以做如下操作：

先将fault中断函数的内容改为:

HardFault_Handler\

PROC

;EXPORT HardFault_Handler [WEAK]

;B .

IMPORT hard_fault_handler_c

TST LR, #4

ITE EQ

MRSEQ R0, MSP

MRSNE R0, PSP

B hard_fault_handler_c

ENDP

然后在源程序里添加下面的函数代码:

// hard fault handler in C,

// with stack frame location as input parameter

void hard_fault_handler_c(unsigned int * hardfault_args)

{

unsigned int stacked_r0;

unsigned int stacked_r1;

unsigned int stacked_r2;

unsigned int stacked_r3;

unsigned int stacked_r12;

unsigned int stacked_lr;

unsigned int stacked_pc;

unsigned int stacked_psr;

stacked_r0 = ((unsigned long) hardfault_args[0]);

stacked_r1 = ((unsigned long) hardfault_args[1]);

stacked_r2 = ((unsigned long) hardfault_args[2]);

stacked_r3 = ((unsigned long) hardfault_args[3]);

stacked_r12 = ((unsigned long) hardfault_args[4]);

stacked_lr = ((unsigned long) hardfault_args[5]);

stacked_pc = ((unsigned long) hardfault_args[6]);

stacked_psr = ((unsigned long) hardfault_args[7]);

printf ("[Hard fault handler]\n");

printf ("R0 = %x\n", stacked_r0);

printf ("R1 = %x\n", stacked_r1);

printf ("R2 = %x\n", stacked_r2);

printf ("R3 = %x\n", stacked_r3);

printf ("R12 = %x\n", stacked_r12);

printf ("LR = %x\n", stacked_lr);

printf ("PC = %x\n", stacked_pc);

printf ("PSR = %x\n", stacked_psr);

printf ("BFAR = %x\n", (*((volatile unsigned long *)(0xE000ED38))));

printf ("CFSR = %x\n", (*((volatile unsigned long *)(0xE000ED28))));

printf ("HFSR = %x\n", (*((volatile unsigned long *)(0xE000ED2C))));

printf ("DFSR = %x\n", (*((volatile unsigned long *)(0xE000ED30))));

printf ("AFSR = %x\n", (*((volatile unsigned long *)(0xE000ED3C))));

while(1)

{

;;

}

如果使用调试器,则可以在第一个printf处设置断点.没有的话看串口打印结果

通过查看stacked_lr的内容可以知道程序运行到哪个位置出现fault

然后查看编译后汇编代码,可以知道源程序是哪个函数哪一步出现问题,

配合其它寄存器的内容来分析找出原因

2．用IAR的话，把startup_ewarm.c文件中的FaultISR（）函数的内容改为：

volatile unsigned int stacked_r0;

volatile unsigned int stacked_r1;

volatile unsigned int stacked_r2;

volatile unsigned int stacked_r3;

volatile unsigned int stacked_r12;

volatile unsigned int stacked_lr;

volatile unsigned int stacked_pc;

volatile unsigned int stacked_psr;

//unsigned long cc;