前言：

针对RISC-V芯片进入HardFault_Handler函数的问题排查提供讲解。

一、HardFault函数添加PC指针打印

在公共文件的sys.c函数中找到函数并修改如下：

__INTERRUPT
__HIGH_CODE
__attribute__((weak))
void HardFault_Handler(void)
{
    uint32_t v_mepc,v_mcause,v_mtval;
    printf("hardfault\n");

    v_mepc=__get_MEPC();
    v_mcause=__get_MCAUSE();
    v_mtval=__get_MTVAL();

    printf("mepc:%08x\n",v_mepc);
    printf("mcause:%08x\n",v_mcause);
    printf("mtval:%08x\n",v_mtval);

#if 0
    FLASH_ROM_SW_RESET();
    sys_safe_access_enable();
    R16_INT32K_TUNE = 0xFFFF;
	sys_safe_access_disable();
    sys_safe_access_enable();
    R8_RST_WDOG_CTRL |= RB_SOFTWARE_RESET;
    sys_safe_access_disable();
#endif
    while(1);
}

二、使用蓝牙工程时可以进一步添加监控函数

__INTERRUPT
__HIGH_CODE
__attribute__((weak))
void HardFault_Handler(void)
{
    struct __MEMORY_CTL
    {
      struct __MEMORY_CTL *  pNext;
      uint16_t len;
      uint16_t used;
    };
    typedef struct __MEMORY_CTL    MemoryCtl;

    extern  MemoryCtl * MemCtlStart;
    extern  MemoryCtl * MemCtlEnd;
    MemoryCtl * MemHead;
    MemHead = MemCtlStart;
    while( MemHead != MemCtlEnd  ){
      printf("|%8x,%8x,%8d.....\n",MemHead->used,(uint32_t)MemHead,\
              (uint32_t)(MemHead->pNext) -(uint32_t)MemHead - sizeof(struct __MEMORY_CTL));
      MemHead = MemHead->pNext;
    }printf("\n");

    uint32_t v_mepc,v_mcause,v_mtval;
    printf("hardfault\n");

    v_mepc=__get_MEPC();
    v_mcause=__get_MCAUSE();
    v_mtval=__get_MTVAL();

    printf("mepc:%08x\n",v_mepc);
    printf("mcause:%08x\n",v_mcause);
    printf("mtval:%08x\n",v_mtval);

#if 0
    FLASH_ROM_SW_RESET();
    sys_safe_access_enable();
    R16_INT32K_TUNE = 0xFFFF;
	sys_safe_access_disable();
    sys_safe_access_enable();
    R8_RST_WDOG_CTRL |= RB_SOFTWARE_RESET;
    sys_safe_access_disable();
#endif
    while(1);
}

注意：监控函数和PC指针可以同时使用。监控函数需要在蓝牙工程中使用才有意义，如果打印值为空，检查是否使用蓝牙。

附录：

PC指针打印信息排查可以参考青稞V4手册：QingKeV4_Processor_Manual.PDF - 南京沁恒微电子股份有限公司 (wch.cn)