单片机硬错误排查方法

1万 · 2021-6-3 16:07

HardFault 错误调试定位方法
1、首先更改 startup.s 的启动文件，把里面的 HardFault_Handler 代码段换成下
面的代码：
HardFault_Handler\
PROC
IMPORT hard_fault_handler_c
TST LR, #4
ITE EQ
MRSEQ R0, MSP
MRSNE R0, PSP
B hard_fault_handler_c
ENDP

1万 · 2021-6-3 16:08

2、然后把 hard_fault_handler_c 函数放在 c 文件的代码中。代码如下：
void hard_fault_handler_c(unsigned int * hardfault_args)
{
      static unsigned int stacked_r0;
      static unsigned int stacked_r1;
      static unsigned int stacked_r2;
      static unsigned int stacked_r3;
      static unsigned int stacked_r12;
      static unsigned int stacked_lr;
      static unsigned int stacked_pc;
      static unsigned int stacked_psr;
      static unsigned int SHCSR;
      static unsigned char MFSR;
      static unsigned char BFSR;
      static unsigned short int UFSR;
      static unsigned int HFSR;
      static unsigned int DFSR;
      static unsigned int MMAR;
      static unsigned int BFAR;
      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]);
      /*异常中断发生时，这个异常模式特定的物理 R14,即 lr 被设置成该异常模式将要返回的
      地址*/
      stacked_lr = ((unsigned long) hardfault_args[5]);
      stacked_pc = ((unsigned long) hardfault_args[6]);
      stacked_psr = ((unsigned long) hardfault_args[7]);
      SHCSR = (*((volatile unsigned long *)(0xE000ED24))); //系统 Handler 控制及状态寄存器
      MFSR = (*((volatile unsigned char *)(0xE000ED28))); //存储器管理 fault 状态寄存器
      BFSR = (*((volatile unsigned char *)(0xE000ED29))); //总线 fault 状态寄存器
      UFSR = (*((volatile unsigned short int *)(0xE000ED2A)));//用法 fault 状态寄存器
      HFSR = (*((volatile unsigned long *)(0xE000ED2C))); //硬 fault 状态寄存器
      DFSR = (*((volatile unsigned long *)(0xE000ED30))); //调试 fault 状态寄存器
      MMAR = (*((volatile unsigned long *)(0xE000ED34))); //存储管理地址寄存器
      BFAR = (*((volatile unsigned long *)(0xE000ED38))); //总线 fault 地址寄存器
      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("SHCSR: %X\n",SHCSR);
      printf("MFSR: %X\n",MFSR);
      printf("DFSR: %X\n",DFSR);
      printf("MMAR: %X\n",MMAR);
      printf("BFAR: %X\n",BFAR);
      printf("UFSR: %X\n",UFSR);
      printf("HFSR: %X\n",HFSR);
      printf("BFSR: %X\n",BFSR);
      while (1);
}

1万 · 2021-6-3 16:08

3、执行程序后，若发生内核错误，则程序会运行到最后的 while(1)处。此时观察相应的堆
栈和故障寄存器值， stacked_lr 即为故障发生时进入故障中断前 pc 的值，在 MDK 软件调试
状态下，假如 stacked_lr 的值为 0x1A002D08，在左下方的命令窗口输入“pc = 0x1A002D08”，
回车，即可定位发生错误的代码位置。

1万 · 2021-6-3 16:08

4、根据内核错误状态寄存器的值，对应下面的说明，也可以看出是发生了何种内核错误。
附录：Cortex-M3 内核错误寄存器说明

单片机硬错误排查方法

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