一、STM32啓動文件詳細解析
STM32啓動文件詳細解析（V3.5.0） 以:startup_stm32f10x_hd.s爲例
;******************** (C) COPYRIGHT 2011 STMicroelectronics ********************
;* File Name : startup_stm32f10x_hd.s
;* Author : MCD Application Team
;* Version : V3.5.0
;* Date : 11-March-2011
;* Description : STM32F10x High Density Devices vector table for MDK-ARM
;* toolchain.
;* This module performs:
;* - Set the initial SP
;* - Set the initial PC == Reset_Handler
;* - Set the vector table entries with the exceptions ISR address
;* - Configure the clock system and also configure the external
;* SRAM mounted on STM3210E-EVAL board to be used as data
;* memory (optional, to be enabled by user)
;* - Branches to __main in the C library (which eventually
;* calls main()).
;* After Reset the CortexM3 processor is in Thread mode,
;* priority is Privileged, and the Stack is set to Main.
;* <<< Use Configuration Wizard in Context Menu >>>
;*******************************************************************************
; THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
; WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME.
; AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT,
; INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE
; CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING
; INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
;*******************************************************************************
; Amount of memory (in bytes) allocated for Stack
; Tailor this value to your application needs
; <h> Stack Configuration ;棧定義
; <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>
Stack_Size EQU 0x00000400 ;EQU僞指令，作用是左邊的符號名代表右邊的表達式</span>
AREA STACK, NOINIT, READWRITE, ALIGN=3 ;定義棧段：名稱爲STACK，未初始化，可讀寫，ELF 的棧段按2^3=8對齊
Stack_Mem SPACE Stack_Size ;分配一片連續的存儲區域並初始化爲 0，棧空間：0x400個字節
__initial_sp ;棧空間頂地址
; <h> Heap Configuration ;堆定義
; <o> Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>
Heap_Size EQU 0x00000200
AREA HEAP, NOINIT, READWRITE, ALIGN=3
__heap_base ;堆空間起始地址
Heap_Mem SPACE Heap_Size ;堆空間:0x200個字節
__heap_limit ;堆空間結束地址
PRESERVE8 ;PRESERVE8 指令指定當前文件保持堆棧八字節對齊
THUMB ;告訴彙編器下面是32位的Thumb指令，如果需要彙編器將插入位以保證對齊
; Vector Table Mapped to Address 0 at Reset ;中斷向量表定義
;實際上是在CODE區（假設STM32從FLASH啓動，則此中斷向量表起始地址即爲0x8000000）
AREA RESET, DATA, READONLY ;定義一塊數據段<DATA>，只可讀<READONLY，默認READWRITE>，段名字是RESET
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
EXPORT __Vectors_End ;在程序中聲明一個全局的標號__Vectors_End
EXPORT __Vectors_Size ;在程序中聲明一個全局的標號__Vectors_Size
;DCD(DCDU)用於分配一片連續的字存儲單元並用指定的數據初始化。
__Vectors DCD __initial_sp ; Top of Stack ;該處物理地址值存儲__initial_sp所表示的地址值,即爲 __Vetors 標號所表示的值
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
; External Interrupts ;以下爲外部中斷向量表
DCD WWDG_IRQHandler ; Window Watchdog
DCD PVD_IRQHandler ; PVD through EXTI Line detect
DCD TAMPER_IRQHandler ; Tamper
DCD RTC_IRQHandler ; RTC
DCD FLASH_IRQHandler ; Flash
DCD RCC_IRQHandler ; RCC
DCD EXTI0_IRQHandler ; EXTI Line 0
DCD EXTI1_IRQHandler ; EXTI Line 1
DCD EXTI2_IRQHandler ; EXTI Line 2
DCD EXTI3_IRQHandler ; EXTI Line 3
DCD EXTI4_IRQHandler ; EXTI Line 4
DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1
DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2
DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3
DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4
DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5
DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6
DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7
DCD ADC1_2_IRQHandler ; ADC1 & ADC2
DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TX
DCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0
DCD CAN1_RX1_IRQHandler ; CAN1 RX1
DCD CAN1_SCE_IRQHandler ; CAN1 SCE
DCD EXTI9_5_IRQHandler ; EXTI Line 9..5
DCD TIM1_BRK_IRQHandler ; TIM1 Break
DCD TIM1_UP_IRQHandler ; TIM1 Update
DCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and Commutation
DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare
DCD TIM2_IRQHandler ; TIM2
DCD TIM3_IRQHandler ; TIM3
DCD TIM4_IRQHandler ; TIM4
DCD I2C1_EV_IRQHandler ; I2C1 Event
DCD I2C1_ER_IRQHandler ; I2C1 Error
DCD I2C2_EV_IRQHandler ; I2C2 Event
DCD I2C2_ER_IRQHandler ; I2C2 Error
DCD SPI1_IRQHandler ; SPI1
DCD SPI2_IRQHandler ; SPI2
DCD USART1_IRQHandler ; USART1
DCD USART2_IRQHandler ; USART2
DCD USART3_IRQHandler ; USART3
DCD EXTI15_10_IRQHandler ; EXTI Line 15..10
DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI Line
DCD USBWakeUp_IRQHandler ; USB Wakeup from suspend
DCD TIM8_BRK_IRQHandler ; TIM8 Break
DCD TIM8_UP_IRQHandler ; TIM8 Update
DCD TIM8_TRG_COM_IRQHandler ; TIM8 Trigger and Commutation
DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare
DCD ADC3_IRQHandler ; ADC3
DCD FSMC_IRQHandler ; FSMC
DCD SDIO_IRQHandler ; SDIO
DCD TIM5_IRQHandler ; TIM5
DCD SPI3_IRQHandler ; SPI3
DCD UART4_IRQHandler ; UART4
DCD UART5_IRQHandler ; UART5
DCD TIM6_IRQHandler ; TIM6
DCD TIM7_IRQHandler ; TIM7
DCD DMA2_Channel1_IRQHandler ; DMA2 Channel1
DCD DMA2_Channel2_IRQHandler ; DMA2 Channel2
DCD DMA2_Channel3_IRQHandler ; DMA2 Channel3
DCD DMA2_Channel4_5_IRQHandler ; DMA2 Channel4 & Channel5
__Vectors_End ;Vectors結束
__Vectors_Size EQU __Vectors_End - __Vectors ;得到向量表的大小,304個字節也就是0x130個字節
AREA |.text|, CODE, READONLY ;定義一個代碼段，可讀，段名字是.text
;|.text| 用於表示由 C 編譯程序產生的代碼段，或用於以某種方式與 C 庫關聯的代碼段
; Reset handler ;利用PROC、ENDP這一對僞指令標記程序開始、結束，把程序段分爲若干個過程，使程序的結構加清晰
Reset_Handler PROC
EXPORT Reset_Handler [WEAK];WEAK聲明其他的同名標號優先於該標號被引用,就是說如果外面聲明瞭的話，調用外面的對應函數
IMPORT __main ;IMPORT:僞指令用於通知編譯器要使用的標號在其他的源文件中定義
IMPORT SystemInit
LDR R0, =SystemInit ;系統初始化
BLX R0 ;帶鏈接的跳轉，切換指令集,跳到SystemInit
LDR R0, =__main ;__main爲運行時庫提供的函數；完成堆棧，堆的初始化等工作，會調用下面定義的__user_initial_stackheap
BX R0 ;切換指令集,main函數不返回跳到__main,進入C的世界
ENDP
; Dummy Exception Handlers (infinite loops which can be modified)
NMI_Handler PROC
EXPORT NMI_Handler [WEAK];不可屏蔽中斷處理函數
B .
ENDP
HardFault_Handler\ ;\意爲換行
PROC
EXPORT HardFault_Handler [WEAK];硬件錯誤處理函數
B .
ENDP
MemManage_Handler\
PROC
EXPORT MemManage_Handler [WEAK]
B .
ENDP
BusFault_Handler\
PROC
EXPORT BusFault_Handler [WEAK]
B .
ENDP
UsageFault_Handler\
PROC
EXPORT UsageFault_Handler [WEAK]
B .
ENDP
SVC_Handler PROC
EXPORT SVC_Handler [WEAK]
B .
ENDP
DebugMon_Handler\
PROC
EXPORT DebugMon_Handler [WEAK]
B .
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler [WEAK]
B .
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler [WEAK]
B .
ENDP
Default_Handler PROC
;輸出異常向量表標號,方便外部實現異常的具體功能,[WEAK]是弱定義的意思,如果外部定義了,優先執行外部定義,否則下面的函數定義
EXPORT WWDG_IRQHandler [WEAK]
EXPORT PVD_IRQHandler [WEAK]
EXPORT TAMPER_IRQHandler [WEAK]
EXPORT RTC_IRQHandler [WEAK]
EXPORT FLASH_IRQHandler [WEAK]
EXPORT RCC_IRQHandler [WEAK]
EXPORT EXTI0_IRQHandler [WEAK]
EXPORT EXTI1_IRQHandler [WEAK]
EXPORT EXTI2_IRQHandler [WEAK]
EXPORT EXTI3_IRQHandler [WEAK]
EXPORT EXTI4_IRQHandler [WEAK]
EXPORT DMA1_Channel1_IRQHandler [WEAK]
EXPORT DMA1_Channel2_IRQHandler [WEAK]
EXPORT DMA1_Channel3_IRQHandler [WEAK]
EXPORT DMA1_Channel4_IRQHandler [WEAK]
EXPORT DMA1_Channel5_IRQHandler [WEAK]
EXPORT DMA1_Channel6_IRQHandler [WEAK]
EXPORT DMA1_Channel7_IRQHandler [WEAK]
EXPORT ADC1_2_IRQHandler [WEAK]
EXPORT USB_HP_CAN1_TX_IRQHandler [WEAK]
EXPORT USB_LP_CAN1_RX0_IRQHandler [WEAK]
EXPORT CAN1_RX1_IRQHandler [WEAK]
EXPORT CAN1_SCE_IRQHandler [WEAK]
EXPORT EXTI9_5_IRQHandler [WEAK]
EXPORT TIM1_BRK_IRQHandler [WEAK]
EXPORT TIM1_UP_IRQHandler [WEAK]
EXPORT TIM1_TRG_COM_IRQHandler [WEAK]
EXPORT TIM1_CC_IRQHandler [WEAK]
EXPORT TIM2_IRQHandler [WEAK]
EXPORT TIM3_IRQHandler [WEAK]
EXPORT TIM4_IRQHandler [WEAK]
EXPORT I2C1_EV_IRQHandler [WEAK]
EXPORT I2C1_ER_IRQHandler [WEAK]
EXPORT I2C2_EV_IRQHandler [WEAK]
EXPORT I2C2_ER_IRQHandler [WEAK]
EXPORT SPI1_IRQHandler [WEAK]
EXPORT SPI2_IRQHandler [WEAK]
EXPORT USART1_IRQHandler [WEAK]
EXPORT USART2_IRQHandler [WEAK]
EXPORT USART3_IRQHandler [WEAK]
EXPORT EXTI15_10_IRQHandler [WEAK]
EXPORT RTCAlarm_IRQHandler [WEAK]
EXPORT USBWakeUp_IRQHandler [WEAK]
EXPORT TIM8_BRK_IRQHandler [WEAK]
EXPORT TIM8_UP_IRQHandler [WEAK]
EXPORT TIM8_TRG_COM_IRQHandler [WEAK]
EXPORT TIM8_CC_IRQHandler [WEAK]
EXPORT ADC3_IRQHandler [WEAK]
EXPORT FSMC_IRQHandler [WEAK]
EXPORT SDIO_IRQHandler [WEAK]
EXPORT TIM5_IRQHandler [WEAK]
EXPORT SPI3_IRQHandler [WEAK]
EXPORT UART4_IRQHandler [WEAK]
EXPORT UART5_IRQHandler [WEAK]
EXPORT TIM6_IRQHandler [WEAK]
EXPORT TIM7_IRQHandler [WEAK]
EXPORT DMA2_Channel1_IRQHandler [WEAK]
EXPORT DMA2_Channel2_IRQHandler [WEAK]
EXPORT DMA2_Channel3_IRQHandler [WEAK]
EXPORT DMA2_Channel4_5_IRQHandler [WEAK]
;如下只是定義一些空函數
WWDG_IRQHandler
PVD_IRQHandler
TAMPER_IRQHandler
RTC_IRQHandler
FLASH_IRQHandler
RCC_IRQHandler
EXTI0_IRQHandler
EXTI1_IRQHandler
EXTI2_IRQHandler
EXTI3_IRQHandler
EXTI4_IRQHandler
DMA1_Channel1_IRQHandler
DMA1_Channel2_IRQHandler
DMA1_Channel3_IRQHandler
DMA1_Channel4_IRQHandler
DMA1_Channel5_IRQHandler
DMA1_Channel6_IRQHandler
DMA1_Channel7_IRQHandler
ADC1_2_IRQHandler
USB_HP_CAN1_TX_IRQHandler
USB_LP_CAN1_RX0_IRQHandler
CAN1_RX1_IRQHandler
CAN1_SCE_IRQHandler
EXTI9_5_IRQHandler
TIM1_BRK_IRQHandler
TIM1_UP_IRQHandler
TIM1_TRG_COM_IRQHandler
TIM1_CC_IRQHandler
TIM2_IRQHandler
TIM3_IRQHandler
TIM4_IRQHandler
I2C1_EV_IRQHandler
I2C1_ER_IRQHandler
I2C2_EV_IRQHandler
I2C2_ER_IRQHandler
SPI1_IRQHandler
SPI2_IRQHandler
USART1_IRQHandler
USART2_IRQHandler
USART3_IRQHandler
EXTI15_10_IRQHandler
RTCAlarm_IRQHandler
USBWakeUp_IRQHandler
TIM8_BRK_IRQHandler
TIM8_UP_IRQHandler
TIM8_TRG_COM_IRQHandler
TIM8_CC_IRQHandler
ADC3_IRQHandler
FSMC_IRQHandler
SDIO_IRQHandler
TIM5_IRQHandler
SPI3_IRQHandler
UART4_IRQHandler
UART5_IRQHandler
TIM6_IRQHandler
TIM7_IRQHandler
DMA2_Channel1_IRQHandler
DMA2_Channel2_IRQHandler
DMA2_Channel3_IRQHandler
DMA2_Channel4_5_IRQHandler
B .
ENDP
ALIGN ;默認是字對齊方式，也說明了代碼是4字節對齊的
;*******************************************************************************
; User Stack and Heap initialization 用戶堆棧初始化
;*******************************************************************************
IF :DEF:__MICROLIB ;判斷是否使用DEF:__MICROLIB（micro lib），如果勾選了micro lib
EXPORT __initial_sp ;將棧頂地址、堆起始地址、堆結束地址賦予全局屬性，使外部程序可用
EXPORT __heap_base
EXPORT __heap_limit
ELSE ;如果沒有勾選micro lib
IMPORT __use_two_region_memory ;兩區堆棧空間，堆和棧有各自的空間地址
EXPORT __user_initial_stackheap
__user_initial_stackheap ;標號__user_initial_stackheap，表示用戶堆棧初始化程序入口
;此處是初始化兩區的堆棧空間，堆是從由低到高的增長，棧是由高向低生長的，兩個是互相獨立的數據段，並不能交叉使用。
LDR R0, = Heap_Mem ;保存堆起始地址
LDR R1, =(Stack_Mem + Stack_Size) ;保存棧結束地址
LDR R2, = (Heap_Mem + Heap_Size) ;保存堆結束地址
LDR R3, = Stack_Mem ;保存棧起始地址
BX LR
ALIGN
ENDIF
END ;END命令指示彙編器,已到達一個源文件的末尾
;******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE*****
二、STM32 中斷向量表的位置 、重定向
知道怎麼跳到main函數了，那麼，中斷髮生後，又是怎麼跑到中斷入口地址的呢？
從stm32f10x.s可以看到，已經定義好了一大堆的中斷響應函數，這就是中斷向量表，標號__Vectors，表示中斷向量表入口地址，例如：
AREA RESET, DATA, READONLY ; 定義只讀數據段，實際上是在CODE區（假設STM32從FLASH啓動，則此中斷向量表起始地址即爲0x8000000）
EXPORT __Vectors
IMPORT OS_CPU_SysTickHandler
IMPORT OS_CPU_PendSVHandler
__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這個向量表的編寫是有講究的，跟硬件一一對應不能亂寫的，CPU找入口地址就靠它了，bin文件開頭就是他們的地址，參考手冊RM0008的10.1.2節可以看到排列。
我們再結合CORTEX-M3的特性，他上電後根據boot引腳來決定PC位置，比如boot設置爲flash啓動，則啓動後PC跳到0x08000000。此時CPU會先取2個地址，第一個是棧頂地址，第二個是復位異常地址，故有了上面的寫法，這樣就跳到reset_handler。
那麼這個reset_handler的實際地址是多少.？下面的一堆例如Nmi_handler地址又是多少呢？發生中斷是怎麼跑到這個地址的呢？下面挨個講解。
1、我們可以通過反向來得知這些入口地址，查看工程下的map文件就可以看到了，這個地址跟keil裏面設置的target->flash起始地址息息相關，實際上我們不太需要關心，讓編譯器分配，中斷向量表放的就是他們的地址。
2、對比ARM7/ARM9內核，Cortex-M3內核則是固定了中斷向量表的位置而起始地址是可變化的。
3、進到C語言後會先配置NVIC，NVIC_SetVectorTable()裏面可以配置中斷向量表的起始地址和偏移，主要是告訴CPU該向量表是位於Flash還是Ram，偏移是多少。例如設置爲位於Flash內，偏移就是燒入的程序地址，可在Keil target中設置。這樣CPU就知道入口地址了。
4、發生中斷後，CPU找到中斷向量表地址，然後根據偏移（對號入座）再找到中斷地址，這樣就跳過去了。
我們截一個圖說明一下，map文件：
對應的bin文件，看是不是放的上面地址：
顯然，200039c0就是棧頂地址，而08006F21就是reset_handler地址！
如何定位？以放到0x20000000爲例
1、keil設置ram起始爲0x20000100，我們在0x20000000~0x20000100放中斷向量表，其他給程序用
2、設置NVIC_SetVectorTable(NVIC_VectTab_FLASH,0);
3、跳到C時把中斷向量表拷貝到0x20000000