1、先在RAM中分配系統(tǒng)使用的棧，RAM的起始地址為0 x2000_0000 然后在RAM中分配變量使用的堆然后在CODE 區(qū) flash 分配中斷向量表，flash 的起始地址為0 x0800_0000 ，該中斷向量表就從這個起始地址開始分配分配完成后，再定義和實現(xiàn)相應的中斷函數(shù)，所有的中斷函數(shù)全部帶有 weak 特性，即弱定義，如果編譯器發(fā)現(xiàn)在別處文件中定義了同名函數(shù)，在鏈接時用別處的地址進行鏈接。中斷函數(shù)僅僅實現(xiàn)了Reset_Handler 其他要么是死循環(huán)，要么僅僅定義了函數(shù)名稱，當 STM32 遇到復位信號STM32 被設置為從內(nèi)部FLASH啟動時（這也是最常見的一種情況）后，CPU-M

2、3會自動從從 0 x0800_0000 處取出棧頂?shù)刂反娣庞贛SP 寄存器，0 x0800_0004 處取出復位中斷服務入口地址放入PC 寄存器，繼而執(zhí)行復位中斷服務程序Reset_Handler，Reset_Handler 僅僅執(zhí)行了兩個函數(shù)調(diào)用一個是 SystemInit ，另一個 _mainSystemInit 定 義 在system_stm32f10 x.c中主要初始化了STM的 時 鐘系統(tǒng) :HSIHSELSILSEPLLSYSCLKUSBCLKAPECLK等等._main 函數(shù)由編譯器生成，負責初始化棧、堆等，并在最后跳轉(zhuǎn)到用戶自定義的 main 函數(shù)，來到 C 的世界。Stack

3、_Size EQU 0 x00000400 / 定義堆棧大小 AREA STACK NOINIT READWRITE ALIGN3 / 定義一個數(shù)據(jù)段 按 8 字節(jié)對齊 AREA 偽指令用于定義一個代碼段或數(shù)據(jù)段NOINIT ：指定此數(shù)據(jù)段僅僅保留了內(nèi)存單元，而沒有將各初始值寫入內(nèi)存單元，或者將各個內(nèi)存單元值初始化為0Stack_Mem SPACE Stack_Size / 保留Stack_Size 大小的堆?？臻g來分配連續(xù)Stack_Size 字節(jié)的存儲單元并初始化為0_initial_sp /標號，代表堆棧頂部地址，后面有用/此標號有一層隱含的意思那就是在M3 中堆棧是滿遞減堆棧，/因為它

4、指定了堆棧指針位于堆棧的高地址（在/Stack_Mem之后）Heap Configuration Heap Size in BytesHeap_Size EQU0 x00000200 / 定義堆空間大小AREA HEAP NOINITREADWRITE ALIGN3 /定義一個數(shù)據(jù)段，8 字節(jié)對齊_heap_base /標號，代表堆末底部地址， 后面有用 Heap_MemSPACE Heap_Size / 保留 Heap_Size 的堆空間 _heap_limit /標號，代表堆界限地址，后面有用PRESERVE8指令指定當前文件保持堆棧八字節(jié)對齊。它設置PRES8編譯屬性以通知鏈接器。鏈接器

5、檢查要求堆棧八字節(jié)對齊的任何代碼是否僅由保持堆棧八字節(jié)對齊的代碼直接或間接地調(diào)用。PRESERVE8 / 指示編譯器8 字節(jié)對齊THUMB /指示編譯器以后的指令為THUMB指令中斷向量表定義在MDK生成的分散加載文件中，RESET被設置在flash的0地址處，這樣就規(guī)定了向量表的地址。 Vector Table Mapped to Address 0 at Reset AREA RESET DATA READONLY / 定義只讀數(shù)據(jù)段，其實放在CODE 區(qū)，位于0 地址EXPORT_Vectors EXPORT ： 在程序中聲明一個全局的標號_Vectors，該標號可在其他的文件中引用EX

6、PORT_Vectors_End EXPORT _Vectors_Size_Vectors DCD_initial_sp Top of Stack 給 _initial_sp 分配 4 字節(jié) 32 位的地址 0 x0 DCD Reset_Handler Reset Handler 給標號ResetHandler 分配地址為0 x00000004 DCD NMI_HandlerNMI Handler給標號NMIHandler分配地址0 x00000008DCD HardFault_Handler Hard Fault Handler DCDMemManage_Handler MPU Fault

7、Handler DCDBusFault_Handler Bus Fault Handler DCD UsageFault_HandlerUsage Fault Handler DCD 0 Reserved 這種形式就是保留地址，不給任何標號分配DCD 0 Reserved DCD 0 ReservedDCD 0 Reserved DCD SVC_Handler SVCall Handler DCDDebugMon_Handler Debug Monitor Handler DCD 0 ReservedDCD PendSV_Handler PendSV Handler DCDSysTick_Ha

8、ndler SysTick Handler External Interrupts DCDWWDG_IRQHandler Window Watchdog DCDPVD_IRQHandler PVD through EXTI Line detect DCDTAMPER_IRQHandler Tamper DCD RTC_IRQHandler RTCDCD FLASH_IRQHandler Flash DCD RCC_IRQHandler RCCDCD EXTI0_IRQHandler EXTI Line 0 DCDEXTI1_IRQHandler EXTI Line 1 DCD EXTI2_IR

9、QHandlerEXTI Line 2 DCD EXTI3_IRQHandler EXTI Line 3DCDEXTI4_IRQHandler EXTI Line 4DCDDMA1_Channel1_IRQHandler DMA1 Channel 1DCDDMA1_Channel2_IRQHandler DMA1 Channel 2DCDDMA1_Channel3_IRQHandler DMA1 Channel 3DCDDMA1_Channel4_IRQHandler DMA1 Channel 4DCDDMA1_Channel5_IRQHandler DMA1 Channel 5DCDDMA1

10、_Channel6_IRQHandler DMA1 Channel 6DCDDMA1_Channel7_IRQHandler DMA1 Channel 7DCDADC1_2_IRQHandler ADC1 ADC2DCDUSB_HP_CAN1_TX_IRQHandler USB High Priority or CAN1TXDCD USB_L P_CAN1_RX0_IRQHandler USB Low Priority or CAN1 RX0DCD CAN1_RX1_IRQHandler CAN1RX1DCD CAN1_SCE_IRQHandler CAN1 SCEDCDEXTI9_5_IRQ

11、Handler EXTI Line 9.5DCDTIM1_BRK_IRQHandler TIM1 BreakDCDTIM1_UP_IRQHandler TIM1 UpdateDCDTIM1_TRG_COM_IRQHandler TIM1 Trigger andCommutationDCD TIM1_CC_IRQHandler TIM1 CaptureCompareDCD TIM2_IRQHandler TIM2DCDTIM3_IRQHandler TIM3DCD TIM4_IRQHandler TIM4DCDI2C1_EV_IRQHandler I2C1 EventDCD I2C1_ER_IR

12、QHandlerI2C1 ErrorDCD I2C2_EV_IRQHandler I2C2 EventDCDI2C2_ER_IRQHandler I2C2 ErrorDCD SPI1_IRQHandlerSPI1DCD SPI2_IRQHandler SPI2DCD USART1_IRQHandlerUSART1DCD USART2_IRQHandler USART2DCDUSART3_IRQHandler USART3DCD EXTI15_10_IRQHandlerEXTI Line 15.10DCD RTCAlarm_IRQHandler RTC Alarmthrough EXTI Lin

13、eDCD USBWakeUp_IRQHandler USBWakeup from suspendDCD TIM8_BRK_IRQHandler TIM8BreakDCD TIM8_UP_IRQHandler TIM8 UpdateDCDTIM8_TRG_COM_IRQHandler TIM8 Trigger andCommutationDCD TIM8_CC_IRQHandler TIM8 CaptureCompareDCD ADC3_IRQHandler ADC3DCDFSMC_IRQHandler FSMCDCD SDIO_IRQHandler SDIODCDTIM5_IRQHandler

14、 TIM5DCD SPI3_IRQHandler SPI3DCDUART4_IRQHandler UART4DCD UART5_IRQHandlerUART5 DCD TIM6_IRQHandler TIM6 DCDTIM7_IRQHandler TIM7 DCD DMA2_Channel1_IRQHandlerDMA2 Channel1 DCD DMA2_Channel2_IRQHandler DMA2Channel2 DCD DMA2_Channel3_IRQHandler DMA2Channel3 DCD DMA2_Channel4_5_IRQHandler DMA2Channel4 C

15、hannel5_Vectors_End_Vectors_Size EQU_Vectors_End - _Vectors AREA .text CODE READONLY代碼段定義Reset Handler 利用PROC、 ENDP 這一對偽指令把程序段分為若干個過程，使程序的結(jié)構(gòu)加清晰Reset_Handler PROC 過程的開始EXPORT Reset_HandlerWEAKWEAK弱定義，意思是如果在別處也定義該標號函數(shù)，在鏈接時用別處的地址。如果沒有其它定方定義，編譯器也不報錯，以此處地址進行鏈接。EXPORT提示編譯器該標號可以為外部文件引用。IMPORT _main通知編譯器要使用

16、的標號在其他文件IMPORT SystemInit LDR R0SystemInit BLX R0 BX是ARM指令集和THUMB指令集之間程序的跳轉(zhuǎn)LDR R0 _main使用 “”表示LDR目前是偽指令不是標準指令。這里是把_main 的地址賦給RO 。BX R0 BX是 ARM指令集和THUMB指令集之間程序的跳轉(zhuǎn)ENDP 過程的結(jié)束Dummy Exception Handlers infiniteloops which can be modifiedNMI_Handler PROC EXPORTNMI_Handler WEAK B .原地跳轉(zhuǎn)即無限循環(huán)，ENDPHardFault_Ha

17、ndler PROC EXPORT HardFault_HandlerWEAK B . ENDPMemManage_Handler PROC EXPORTMemManage_Handler WEAK B . ENDPBusFault_HandlerPROC EXPORT BusFault_Handler WEAK B .ENDPUsageFault_Handler PROC EXPORTUsageFault_Handler WEAK B . ENDPSVC_Handler PROCEXPORT SVC_Handler WEAK B . ENDPDebugMon_HandlerPROC EXPO

18、RT DebugMon_Handler WEAK B .ENDPPendSV_Handler PROC EXPORT PendSV_HandlerWEAK B . ENDPSysTick_Handler PROC EXPORTSysTick_Handler WEAK B . ENDPDefault_Handler PROCEXPORT WWDG_IRQHandler WEAK EXPORTPVD_IRQHandler WEAK EXPORT TAMPER_IRQHandlerWEAK EXPORT RTC_IRQHandler WEAK EXPORTFLASH_IRQHandler WEAK

19、EXPORT RCC_IRQHandlerWEAK EXPORT EXTI0_IRQHandler WEAK EXPORTEXTI1_IRQHandler WEAK EXPORT EXTI2_IRQHandlerWEAK EXPORT EXTI3_IRQHandler WEAK EXPORTEXTI4_IRQHandler WEAK EXPORTDMA1_Channel1_IRQHandler WEAK EXPORTDMA1_Channel2_IRQHandler WEAK EXPORTDMA1_Channel3_IRQHandler WEAK EXPORTDMA1_Channel4_IRQH

20、andler WEAK EXPORTDMA1_Channel5_IRQHandler WEAK EXPORTDMA1_Channel6_IRQHandler WEAK EXPORTDMA1_Channel7_IRQHandler WEAK EXPORTADC1_2_IRQHandler WEAK EXPORTUSB_HP_CAN1_TX_IRQHandler WEAK EXPORTUSB_LP_CAN1_RX0_IRQHandler WEAK EXPORTCAN1_RX1_IRQHandler WEAK EXPORTCAN1_SCE_IRQHandler WEAK EXPORTEXTI9_5_

21、IRQHandler WEAK EXPORTTIM1_BRK_IRQHandler WEAK EXPORTTIM1_UP_IRQHandler WEAK EXPORTTIM1_TRG_COM_IRQHandler WEAK EXPORTTIM1_CC_IRQHandler WEAK EXPORT TIM2_IRQHandlerWEAK EXPORT TIM3_IRQHandler WEAK EXPORTTIM4_IRQHandler WEAK EXPORT I2C1_EV_IRQHandlerWEAK EXPORT I2C1_ER_IRQHandler WEAK EXPORTI2C2_EV_I

22、RQHandler WEAK EXPORTI2C2_ER_IRQHandler WEAK EXPORT SPI1_IRQHandlerWEAK EXPORT SPI2_IRQHandler WEAK EXPORTUSART1_IRQHandler WEAK EXPORTUSART2_IRQHandler WEAK EXPORTUSART3_IRQHandler WEAK EXPORTEXTI15_10_IRQHandler WEAK EXPORTRTCAlarm_IRQHandler WEAK EXPORTUSBWakeUp_IRQHandler WEAK EXPORTTIM8_BRK_IRQ

23、Handler WEAK EXPORTTIM8_UP_IRQHandler WEAK EXPORTTIM8_TRG_COM_IRQHandler WEAK EXPORTTIM8_CC_IRQHandler WEAK EXPORT ADC3_IRQHandlerWEAK EXPORT FSMC_IRQHandler WEAK EXPORTSDIO_IRQHandler WEAK EXPORT TIM5_IRQHandlerWEAK EXPORT SPI3_IRQHandler WEAK EXPORTUART4_IRQHandler WEAK EXPORT UART5_IRQHandlerWEAK

24、 EXPORT TIM6_IRQHandler WEAK EXPORTTIM7_IRQHandler WEAK EXPORTDMA2_Channel1_IRQHandler WEAK EXPORTDMA2_Channel2_IRQHandler WEAK EXPORTDMA2_Channel3_IRQHandler WEAK EXPORTDMA2_Channel4_5_IRQHandlerWEAKWWDG_IRQHandlerPVD_IRQHandlerTAMPER_IRQHandlerRTC_IRQHandlerFLASH_IRQHandlerRCC_IRQHandlerEXTI0_IRQH

25、andlerEXTI1_IRQHandlerEXTI2_IRQHandlerEXTI3_IRQHandlerEXTI4_IRQHandlerDMA1_Channel1_IRQHandlerDMA1_Channel2_IRQHandlerDMA1_Channel3_IRQHandlerDMA1_Channel4_IRQHandlerDMA1_Channel5_IRQHandlerDMA1_Channel6_IRQHandlerDMA1_Channel7_IRQHandlerADC1_2_IRQHandlerUSB_HP_CAN1_TX_IRQHandlerUSB_LP_CAN1_RX0_IRQH

26、andlerCAN1_RX1_IRQHandlerCAN1_SCE_IRQHandlerEXTI9_5_IRQHandlerTIM1_BRK_IRQHandlerTIM1_UP_IRQHandlerTIM1_TRG_COM_IRQHandlerTIM1_CC_IRQHandlerTIM2_IRQHandlerTIM3_IRQHandlerT IM4_IRQHandlerI2C1_EV_IRQHandlerI2C1_ER_IRQHandler I2C2_EV_IRQHandlerI2C2_ER_IRQHandlerSPI1_IRQHandler SPI2_IRQHandlerUSART1_IRQHandlerUSART2_IRQHandler USART3_IRQHandlerEXTI15_10_IRQHandlerRTCAlarm_IR QHandlerUSBWakeUp_IRQHandlerTIM8_BRK_IRQHandlerT IM8_UP_IRQHandlerTIM8_TRG_COM_IRQHandlerTIM8_C C_IRQHandlerADC3_IRQHandlerFSMC_IRQHandlerSDIO_I RQHandlerTIM5_I