Cortex-M3 内核HardFault错误调试定位方法.docx

Cortex-M3 内核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
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
while (1);
}
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。

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