瑞萨单片机学习：RA4M3单片机 BOOTloader升级 跳转到主程序 主程序无法执行问题

?背景：

使用瑞萨的RA4M3单片机编写BOOT引导程序进行测试，在BOOT程序跳转到主程序时，主程序无法执行。本文介绍了问题的定位和解决方法。

运行开发环境介绍

?一开始从BOOT更新了APP FLASH后，然后跳转主程序APP地址，发现程序无法执行，注释掉下面的代码就可以。

SystemInit()

但是这样系统时钟没有经过初始化，延时函数会出问题。

后来 经过挨着注释? 最好发现注释掉函数里的下面这行就能跳转了。

    /* Call Post C runtime initialization hook. */
   // R_BSP_WarmStart(BSP_WARM_START_POST_C);

/*******************************************************************************************************************//**
 * Initialize the MCU and the runtime environment.
 **********************************************************************************************************************/
void SystemInit (void)
{
//    *__Vectors =  (uint32_t * )0x00038000;
#if __FPU_USED

    /* Enable the FPU only when it is used.
     * Code taken from Section 7.1, Cortex-M4 TRM (DDI0439C) */

    /* Set bits 20-23 (CP10 and CP11) to enable FPU. */
    SCB->CPACR = (uint32_t) CP_MASK;
#endif

#if BSP_TZ_SECURE_BUILD

    /* Seal the main stack for secure projects. Reference:
     * https://developer.arm.com/documentation/100720/0300
     * https://developer.arm.com/support/arm-security-updates/armv8-m-stack-sealing */
    uint32_t * p_main_stack_top = (uint32_t *) __Vectors[0];
    *p_main_stack_top = BSP_TZ_STACK_SEAL_VALUE;
#endif

#if !BSP_TZ_NONSECURE_BUILD

    /* VTOR is in undefined state out of RESET:
     * https://developer.arm.com/documentation/100235/0004/the-cortex-m33-peripherals/system-control-block/system-control-block-registers-summary?lang=en.
     * Set the Secure/Non-Secure VTOR to the vector table address based on the build. This is skipped for non-secure
     * projects because SCB_NS->VTOR is set by the secure project before the non-secure project runs. */
//    SCB->VTOR = (uint32_t) &__Vectors;
    SCB->VTOR = (uint32_t)&__Vectors;
#endif

#if !BSP_TZ_CFG_SKIP_INIT
 #if BSP_FEATURE_BSP_VBATT_HAS_VBTCR1_BPWSWSTP

    /* Unlock VBTCR1 register. */
    R_SYSTEM->PRCR = (uint16_t) BSP_PRV_PRCR_PRC1_UNLOCK;

    /* The VBTCR1.BPWSWSTP must be set after reset on MCUs that have VBTCR1.BPWSWSTP. Reference section 11.2.1
     * "VBATT Control Register 1 (VBTCR1)" and Figure 11.2 "Setting flow of the VBTCR1.BPWSWSTP bit" in the RA4M1 manual
     * R01UM0007EU0110. This must be done before bsp_clock_init because LOCOCR, LOCOUTCR, SOSCCR, and SOMCR cannot
     * be accessed until VBTSR.VBTRVLD is set. */
    R_SYSTEM->VBTCR1 = 1U;
    FSP_HARDWARE_REGISTER_WAIT(R_SYSTEM->VBTSR_b.VBTRVLD, 1U);

    /* Lock VBTCR1 register. */
    R_SYSTEM->PRCR = (uint16_t) BSP_PRV_PRCR_LOCK;
 #endif
#endif

#if BSP_FEATURE_TFU_SUPPORTED
    R_BSP_MODULE_START(FSP_IP_TFU, 0U);
#endif

#if BSP_CFG_EARLY_INIT

    /* Initialize uninitialized BSP variables early for use in R_BSP_WarmStart. */
    bsp_init_uninitialized_vars();
#endif

    /* Call pre clock initialization hook. */
    R_BSP_WarmStart(BSP_WARM_START_RESET);

#if BSP_TZ_CFG_SKIP_INIT

    /* Initialize clock variables to be used with R_BSP_SoftwareDelay. */
    bsp_clock_freq_var_init();
#else

    /* Configure system clocks. */
    bsp_clock_init();

 #if BSP_FEATURE_BSP_RESET_TRNG

    /* To prevent an undesired current draw, this MCU requires a reset
     * of the TRNG circuit after the clocks are initialized */

    bsp_reset_trng_circuit();
 #endif
#endif

    /* Call post clock initialization hook. */
    R_BSP_WarmStart(BSP_WARM_START_POST_CLOCK);

#if BSP_FEATURE_BSP_HAS_SP_MON

    /* Disable MSP monitoring  */
    R_MPU_SPMON->SP[0].CTL = 0;

    /* Setup NMI interrupt  */
    R_MPU_SPMON->SP[0].OAD = BSP_STACK_POINTER_MONITOR_NMI_ON_DETECTION;

    /* Setup start address  */
    R_MPU_SPMON->SP[0].SA = BSP_PRV_STACK_LIMIT;

    /* Setup end address  */
    R_MPU_SPMON->SP[0].EA = BSP_PRV_STACK_TOP;

    /* Set SPEEN bit to enable NMI on stack monitor exception. NMIER bits cannot be cleared after reset, so no need
     * to read-modify-write. */
    R_ICU->NMIER = R_ICU_NMIER_SPEEN_Msk;

    /* Enable MSP monitoring  */
    R_MPU_SPMON->SP[0].CTL = 1U;
#endif

#if BSP_FEATURE_TZ_HAS_TRUSTZONE

    /* Use CM33 stack monitor. */
    __set_MSPLIM(BSP_PRV_STACK_LIMIT);
//    __set_MSPLIM(0);
#endif

#if BSP_CFG_C_RUNTIME_INIT

    /* Initialize C runtime environment. */
    /* Zero out BSS */
 #if defined(__ARMCC_VERSION)
    memset((uint8_t *) &Image$$BSS$$ZI$$Base, 0U, (uint32_t) &Image$$BSS$$ZI$$Length);
 #elif defined(__GNUC__)
    memset(&__bss_start__, 0U, ((uint32_t) &__bss_end__ - (uint32_t) &__bss_start__));
 #elif defined(__ICCARM__)
    memset((uint32_t *) __section_begin(".bss"), 0U, (uint32_t) __section_size(".bss"));
 #endif

    /* Copy initialized RAM data from ROM to RAM. */
 #if defined(__ARMCC_VERSION)
    memcpy((uint8_t *) &Image$$DATA$$Base, (uint8_t *) &Load$$DATA$$Base, (uint32_t) &Image$$DATA$$Length);
 #elif defined(__GNUC__)
    memcpy(&__data_start__, &__etext, ((uint32_t) &__data_end__ - (uint32_t) &__data_start__));
 #elif defined(__ICCARM__)
    memcpy((uint32_t *) __section_begin(".data"), (uint32_t *) __section_begin(".data_init"),
           (uint32_t) __section_size(".data"));

    /* Copy functions to be executed from RAM. */
  #pragma section=".code_in_ram"
  #pragma section=".code_in_ram_init"
    memcpy((uint32_t *) __section_begin(".code_in_ram"),
           (uint32_t *) __section_begin(".code_in_ram_init"),
           (uint32_t) __section_size(".code_in_ram"));

    /* Copy main thread TLS to RAM. */
  #pragma section="__DLIB_PERTHREAD_init"
  #pragma section="__DLIB_PERTHREAD"
    memcpy((uint32_t *) __section_begin("__DLIB_PERTHREAD"), (uint32_t *) __section_begin("__DLIB_PERTHREAD_init"),
           (uint32_t) __section_size("__DLIB_PERTHREAD_init"));
 #endif

    /* Initialize static constructors */
 #if defined(__ARMCC_VERSION)
    int32_t count = Image$$INIT_ARRAY$$Limit - Image$$INIT_ARRAY$$Base;
    for (int32_t i = 0; i < count; i++)
    {
        void (* p_init_func)(void) =
            (void (*)(void))((uint32_t) &Image$$INIT_ARRAY$$Base + (uint32_t) Image$$INIT_ARRAY$$Base[i]);
        p_init_func();
    }

 #elif defined(__GNUC__)
    int32_t count = __init_array_end - __init_array_start;
    for (int32_t i = 0; i < count; i++)
    {
        __init_array_start[i]();
    }

 #elif defined(__ICCARM__)
    void const * pibase = __section_begin("SHT$$PREINIT_ARRAY");
    void const * ilimit = __section_end("SHT$$INIT_ARRAY");
    __call_ctors(pibase, ilimit);
 #endif
#endif                                 // BSP_CFG_C_RUNTIME_INIT

    /* Initialize SystemCoreClock variable. */
    SystemCoreClockUpdate();

#if !BSP_CFG_PFS_PROTECT
 #if BSP_TZ_SECURE_BUILD
    R_PMISC->PWPRS = 0;                              ///< Clear BOWI bit - writing to PFSWE bit enabled
    R_PMISC->PWPRS = 1U << BSP_IO_PWPR_PFSWE_OFFSET; ///< Set PFSWE bit - writing to PFS register enabled
 #else
    R_PMISC->PWPR = 0;                               ///< Clear BOWI bit - writing to PFSWE bit enabled
    R_PMISC->PWPR = 1U << BSP_IO_PWPR_PFSWE_OFFSET;  ///< Set PFSWE bit - writing to PFS register enabled
 #endif
#endif

#if FSP_PRIV_TZ_USE_SECURE_REGS

    /* Ensure that the PMSAR registers are reset (Soft reset does not reset PMSAR). */
    R_BSP_RegisterProtectDisable(BSP_REG_PROTECT_SAR);

    for (uint32_t i = 0; i < 9; i++)
    {
        R_PMISC->PMSAR[i].PMSAR = UINT16_MAX;
    }
    R_BSP_RegisterProtectEnable(BSP_REG_PROTECT_SAR);
#endif

#if BSP_TZ_SECURE_BUILD

    /* Initialize security features. */
    R_BSP_SecurityInit();
#endif

    /* Call Post C runtime initialization hook. */
   // R_BSP_WarmStart(BSP_WARM_START_POST_C);

    /* Initialize ELC events that will be used to trigger NVIC interrupts. */
    bsp_irq_cfg();

    /* Call any BSP specific code. No arguments are needed so NULL is sent. */
    bsp_init(NULL);
}