Tiva C DevBoard - 微控制器无法进入主函数

Question

我正在使用 Tiva C EK-TM4C123GXL 开发板（MCU -> TM4C123GH6P）。对于这个特定的微控制器，我使用 Keil uVision 5、ARM 编译器 6.12 和 CMSIS 包。 我的代码如下：

#include "TM4C123GH6PM.h"  // CMSIS-compatible interface

#include <stdint.h> // C99 standard integers

#define LED_RED   (1U << 1)
#define LED_BLUE  (1U << 2)
#define LED_GREEN (1U << 3)

void delay(int volatile iter);

int main(void) {

    SYSCTL->RCGCGPIO  |= (1U << 5); /* enable AHB for GPIOF */
    SYSCTL->GPIOHBCTL |= (1U << 5); /* enable clock for GPIOF */

    /* configure LEDs (digital output) */
    GPIOF_AHB->DIR |= (LED_RED | LED_BLUE | LED_GREEN);
    GPIOF_AHB->DEN |= (LED_RED | LED_BLUE | LED_GREEN);

    /* turn all LEDs off */
    GPIOF_AHB->DATA_Bits[LED_RED | LED_BLUE | LED_GREEN] = 0U;

    GPIOF_AHB->DATA_Bits[LED_BLUE] = LED_BLUE;
    while (1) {
        GPIOF_AHB->DATA_Bits[LED_RED] = LED_RED;
        delay(500000);

        GPIOF_AHB->DATA_Bits[LED_RED] = 0;

        delay(250000);
    }
    return 0; // unreachable code
}

void delay(int volatile iter) {
    while (iter > 0) {  // delay loop
        --iter;
    }
}

构建后，我收到以下警告，但我能够加载代码：

.\RTE\Device\ARMCM0\ARMCM0_ac6.sct(19): warning: L6314W: No section matches pattern *(.bss.noinit).

调试会话从输入 Reset_Handler（在启动文件内）开始：

Reset_Handler   PROC
                EXPORT  Reset_Handler             [WEAK]
                IMPORT  SystemInit
                IMPORT  __main
                LDR     R0, =SystemInit
                BLX     R0
                LDR     R0, =__main
                BX      R0
                ENDP

函数

SystemInit

执行没有任何问题，但是当执行

__main

时，程序跳转到

HardFault_Handler

并保持永远循环。 到目前为止，我尝试修改堆栈大小，但没有结果。同样，我修改了堆大小，但问题仍然存在。我尝试使用 IAR，但问题变得更严重。

在网上搜索了一下，发现很多人在相同的DevBoard上都遇到了类似的问题，但我仍然找不到解决方案。

Answer 1

很可能您的项目设置不正确，并且您没有针对正确的 MCU 进行编译：

1. .\RTE\Device\ARMCM0\ARMCM0_ac6.sct(19):

   您的 MCU 是

   M4

   ，此消息表明您使用了一些

   M0

   分散文件。

2. 测试

   LDR     R0, =__main

   是否使用已设置LSB的地址加载R0（以指示拇指模式）。如果不是，那么您就不会在拇指模式下编译。

3. 检查 HF 的原因（将

   printf

   替换为任何可用的内容） - 甚至只是放置断点并查看执行了什么

// Base address for System Control Space (SCB)
#define SCB_BASE 0xE000ED00

// Registers for fault status
#define SCB_HFSR   (*(volatile uint32_t *)(SCB_BASE + 0x02C)) // Hard Fault Status Register
#define SCB_CFSR   (*(volatile uint32_t *)(SCB_BASE + 0x028)) // Configurable Fault Status Register
#define SCB_MMAR   (*(volatile uint32_t *)(SCB_BASE + 0x034)) // Memory Management Fault Address Register
#define SCB_BFAR   (*(volatile uint32_t *)(SCB_BASE + 0x038)) // Bus Fault Address Register
#define SCB_AIRCR  (*(volatile uint32_t *)(SCB_BASE + 0x00C)) // Application Interrupt and Reset Control Register

void displayHardwareFaultReason()
{

    // Read the Hard Fault Status Register (HFSR)
    uint32_t hfsr = SCB_HFSR;
    if (hfsr & (1 << 30))
    {
        printf("FORCED: A configurable fault (such as usage, bus, or memory fault) escalated to hard fault.\n");

        // Read the Configurable Fault Status Register (CFSR)
        uint32_t cfsr = SCB_CFSR;

        // Check memory management faults
        if (cfsr & 0xFF) // MMFSR: Bits [7:0]
        {
            printf("Memory Management Fault Detected:\n");
            if (cfsr & (1 << 0)) printf("  IACCVIOL: Instruction access violation.\n");
            if (cfsr & (1 << 1)) printf("  DACCVIOL: Data access violation.\n");
            if (cfsr & (1 << 3)) printf("  MUNSTKERR: Unstacking error during exception return.\n");
            if (cfsr & (1 << 4)) printf("  MSTKERR: Stacking error during exception entry.\n");
            if (cfsr & (1 << 7))
            {
                printf("  MMARVALID: MMAR contains the address of the faulting access: 0x%08X\n", SCB_MMAR);
            }
        }

        // Check bus faults
        if (cfsr & 0xFF00) // BFSR: Bits [15:8]
        {
            printf("Bus Fault Detected:\n");
            if (cfsr & (1 << 8)) printf("  IBUSERR: Instruction bus error.\n");
            if (cfsr & (1 << 9)) printf("  PRECISERR: Precise data bus error.\n");
            if (cfsr & (1 << 10)) printf("  IMPRECISERR: Imprecise data bus error.\n");
            if (cfsr & (1 << 11)) printf("  UNSTKERR: Unstacking error during exception return.\n");
            if (cfsr & (1 << 12)) printf("  STKERR: Stacking error during exception entry.\n");
            if (cfsr & (1 << 15))
            {
                printf("  BFARVALID: BFAR contains the address of the faulting access: 0x%08X\n", SCB_BFAR);
            }
        }

        // Check usage faults
        if (cfsr & 0xFFFF0000) // UFSR: Bits [31:16]
        {
            printf("Usage Fault Detected:\n");
            if (cfsr & (1 << 16)) printf("  UNDEFINSTR: Undefined instruction.\n");
            if (cfsr & (1 << 17)) printf("  INVSTATE: Invalid state.\n");
            if (cfsr & (1 << 18)) printf("  INVPC: Invalid program counter.\n");
            if (cfsr & (1 << 19)) printf("  NOCP: No coprocessor available.\n");
            if (cfsr & (1 << 24)) printf("  UNALIGNED: Unaligned memory access.\n");
            if (cfsr & (1 << 25)) printf("  DIVBYZERO: Division by zero.\n");
        }
    }
    else if (hfsr & (1 << 1))
    {
        printf("VECTBL: Bus fault on vector table read during exception processing.\n");
    }
    else
    {
        printf("No forced faults detected.\n");
    }

}