软件到底是如何控制硬件的？一步步分析单片机程序如何编译、运行

GPIO_SetBits(GPIOG, GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2| GPIO_Pin_3);

void GPIO_SetBits(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin){ /* Check the parameters */ assert_param(IS_GPIO_ALL_PERIPH(GPIOx)); assert_param(IS_GPIO_PIN(GPIO_Pin));
 GPIOx->BSRRL = GPIO_Pin;}

#define GPIOG               ((GPIO_TypeDef *) GPIOG_BASE)

#define GPIOG_BASE           (AHB1PERIPH_BASE + 0x1800)

/*!< Peripheral memory map */#define APB1PERIPH_BASE       PERIPH_BASE#define APB2PERIPH_BASE       (PERIPH_BASE + 0x00010000)#define AHB1PERIPH_BASE       (PERIPH_BASE + 0x00020000)#define AHB2PERIPH_BASE       (PERIPH_BASE + 0x10000000)

#define PERIPH_BASE           ((uint32_t)0x40000000)

u32 i;i = 0x55aa55aa;

; Vector Table Mapped to Address 0 at Reset                AREA    RESET, DATA, READONLY                EXPORT  __Vectors                EXPORT  __Vectors_End                EXPORT  __Vectors_Size
__Vectors       DCD     __initial_sp               ; Top of Stack                DCD     Reset_Handler              ; Reset Handler                DCD     NMI_Handler                ; NMI Handler                DCD     HardFault_Handler          ; Hard Fault Handler                DCD     MemManage_Handler          ; MPU Fault Handler                DCD     BusFault_Handler           ; Bus Fault Handler                DCD     UsageFault_Handler         ; Usage Fault Handler

int main(void){  GPIO_InitTypeDef GPIO_InitStructure;
 /*!< At this stage the microcontroller clock setting is already configured,       this is done through SystemInit() function which is called from startup       files before to branch to application main.       To reconfigure the default setting of SystemInit() function,       refer to system_stm32f4xx.c file */
  /* SysTick end of count event each 10ms */  RCC_GetClocksFreq(&RCC_Clocks);  SysTick_Config(RCC_Clocks.HCLK_Frequency / 100);
  /* Add your application code here */  /* Insert 50 ms delay */  Delay(5);

/*初始化LED IO口*/RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOG, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2| GPIO_Pin_3;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;GPIO_Init(GPIOG, &GPIO_InitStructure);    
/* Infinite loop */mcu_uart_open(3);while (1){  GPIO_ResetBits(GPIOG, GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3);  Delay(100);  GPIO_SetBits(GPIOG, GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3);  Delay(100);  mcu_uart_test();
  TestFun(TestTmp2);}

/* Private functions ---------------------------------------------------------*/u32 TestTmp1 = 5;//全局变量，初始化为5u32 TestTmp2;//全局变量，未初始化
const u32 TestTmp3[10] = {6,7,8,9,10,11,12,13,12,13};
u8 TestFun(u32 x)//函数，带一个参数，并返回一个u8值{ u8 test_tmp1 = 4;//局部变量，初始化 u8 test_tmp2;//局部变量，未初始化
 static u8 test_tmp3 = 0;//静态局部变量
 test_tmp3++;
 test_tmp2 = x;
 if(test_tmp2> TestTmp1)  test_tmp1 = 10; else  test_tmp1 = 5;
 TestTmp2 +=TestTmp3[test_tmp1];
 return test_tmp1;}

/**  * @brief  Inserts a delay time.  * @param  nTime: specifies the delay time length, in milliseconds.  * @retval None  */void Delay(__IO uint32_t nTime){  uwTimingDelay = nTime;
  while(uwTimingDelay != 0);}

/**  * @brief  Decrements the TimingDelay variable.  * @param  None  * @retval None  */void TimingDelay_Decrement(void){  if (uwTimingDelay != 0x00)  {    uwTimingDelay--;  }}

/**  * @brief  This function handles SysTick Handler.  * @param  None  * @retval None  */void SysTick_Handler(void){  TimingDelay_Decrement();}

__Vectors       DCD     __initial_sp               ; Top of Stack                DCD     Reset_Handler              ; Reset Handler                DCD     NMI_Handler                ; NMI Handler                DCD     HardFault_Handler          ; Hard Fault Handler                DCD     MemManage_Handler          ; MPU Fault Handler                DCD     BusFault_Handler           ; Bus Fault Handler                DCD     UsageFault_Handler         ; Usage Fault Handler                DCD     0                          ; Reserved                DCD     0                          ; Reserved                DCD     0                          ; Reserved                DCD     0                          ; Reserved                DCD     SVC_Handler                ; SVCall Handler                DCD     DebugMon_Handler           ; Debug Monitor Handler                DCD     0                          ; Reserved                DCD     PendSV_Handler             ; PendSV Handler                DCD     SysTick_Handler            ; SysTick Handler

*** Using Compiler 'V5.06 update 5 (build 528)', folder: 'C:\Keil_v5\ARM\ARMCC\Bin'Build target 'wujique'compiling stm32f4xx_it.c......assembling startup_stm32f40_41xxx.s...compiling misc.c......compiling mcu_uart.c...linking...Program Size: Code=9038 RO-data=990 RW-data=40 ZI-data=6000  FromELF: creating hex file...".\Objects\wujique.axf" - 0 Error(s), 0 Warning(s).Build Time Elapsed:  00:00:32

#include #include #include 

u8 TestFun(u32 x)//函数，带一个参数，并返回一个u8值{ u8 test_tmp1 = 4;//局部变量，初始化 u8 test_tmp2;//局部变量，未初始化
 static u8 test_tmp3 = 0;//静态局部变量

*(InRoot$$Sections)