使用單片機STM32執行的第一個程序是startup_stm32f407xx.s
| 指令名稱 | 含義 |
|---|---|
| EQU | 給數字常量取一個符號名，相當於C語言中的define |
| AREA | 彙編一個新的代碼段或者數據段 |
| SPACE | 分配內存空間 |
| PRESERVE8 | 當前文件堆棧需按照8字節對齊 |
| EXPORT | 聲明一個具有全局屬性的標號，可被外部文件使用 |
| IMPORT | 聲明一個來自外部文件的標號 |
| DCD | 以字爲單位分配內存，要求4字節對齊，並要求初始化這些內存 |
| PROC | 定義子程序，與ENDP成對使用 |
| ENDP | 表示子程序結束 |
| WEAK | 弱定義，如果外部文件定義了一個標號，則優先使用外部文件的標號，是ARM僞指令 |
| ALIGN | 編譯器對指令或數據的存放地址進行對齊，缺省表示4字節對齊，是ARM僞指令 |
| IF,ELSE,ENDIF | 彙編條件分支語句，同C語言的類似 |
| LDR | 從存儲器中加載字到一個寄存器中 |
| B | 跳轉到一個標號 |
| BL | 跳轉到由寄存器/標號給出的地址，並保存跳轉前的下條指令至LR中 |
| BX | 跳轉到由寄存器/標號給出的地址，並根據寄存器的LSE確定處理器的狀態 |
| BLX | 跳轉到由寄存器/標號給出的地址，並根據寄存器的LSE確定處理器的狀態，同時保存跳轉前的下條指令至LR中 |
| END | 到達文件的末尾，文件結束 |
Stack_Size EQU 0x00000400 //stack_size = 0x00000400
AREA STACK, NOINIT, READWRITE, ALIGN=3//定義棧區,不初始化，可讀可寫，2^8字節對齊
Stack_Mem SPACE Stack_Size//分配stack_size大小的空間，Stack_mem是分配空間的起始位置，即棧底的地址
__initial_sp //地址標號，表示棧的結束地址，用來指向棧頂地址
Heap_Size EQU 0x00000200//Heap_size = 0x00000200
AREA HEAP, NOINIT, READWRITE, ALIGN=3//定義堆區,不初始化，可讀可寫，2^8字節對齊
__heap_base//地址標號，用來指向堆的起始地址
Heap_Mem SPACE Heap_Size//分配Heap_Size大小的空間，Heap_mem是分配空間的起始地址
__heap_limit//地址標號，用來指向堆的結束地址
PRESERVE8//當前文件的堆棧8字節對齊
THUMB//告訴編譯器下面採用32位Thumb指令
; Vector Table Mapped to Address 0 at Reset
AREA RESET, DATA, READONLY//定義復位區,只讀，
EXPORT __Vectors//定義可在其他文件使用的全局標號，此處表示中斷向量表的地址
EXPORT __Vectors_End//定義可在其他文件使用的全局標號，此處表示中斷向量表的結束地址
EXPORT __Vectors_Size//定義可在其他文件使用的全局標號，此處表示中斷向量表的大小
__Vectors DCD __initial_sp ; Top of Stack//分配四字節空間，存放標號_inital_sp的地址
DCD Reset_Handler ; Reset Handler//分配四字節空間，存放標號Reset_Handler的地址
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//保留，不給任何標號分配
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
DCD WWDG_IRQHandler ; Window WatchDog
DCD PVD_IRQHandler ; PVD through EXTI Line detection
DCD TAMP_STAMP_IRQHandler ; Tamper and TimeStamps through the EXTI line
DCD RTC_WKUP_IRQHandler ; RTC Wakeup through the EXTI line
DCD FLASH_IRQHandler ; FLASH
DCD RCC_IRQHandler ; RCC
DCD EXTI0_IRQHandler ; EXTI Line0
DCD EXTI1_IRQHandler ; EXTI Line1
DCD EXTI2_IRQHandler ; EXTI Line2
DCD EXTI3_IRQHandler ; EXTI Line3
DCD EXTI4_IRQHandler ; EXTI Line4
DCD DMA1_Stream0_IRQHandler ; DMA1 Stream 0
DCD DMA1_Stream1_IRQHandler ; DMA1 Stream 1
DCD DMA1_Stream2_IRQHandler ; DMA1 Stream 2
DCD DMA1_Stream3_IRQHandler ; DMA1 Stream 3
DCD DMA1_Stream4_IRQHandler ; DMA1 Stream 4
DCD DMA1_Stream5_IRQHandler ; DMA1 Stream 5
DCD DMA1_Stream6_IRQHandler ; DMA1 Stream 6
DCD ADC_IRQHandler ; ADC1, ADC2 and ADC3s
DCD CAN1_TX_IRQHandler ; CAN1 TX
DCD CAN1_RX0_IRQHandler ; CAN1 RX0
DCD CAN1_RX1_IRQHandler ; CAN1 RX1
DCD CAN1_SCE_IRQHandler ; CAN1 SCE
DCD EXTI9_5_IRQHandler ; External Line[9:5]s
DCD TIM1_BRK_TIM9_IRQHandler ; TIM1 Break and TIM9
DCD TIM1_UP_TIM10_IRQHandler ; TIM1 Update and TIM10
DCD TIM1_TRG_COM_TIM11_IRQHandler ; TIM1 Trigger and Commutation and TIM11
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 ; External Line[15:10]s
DCD RTC_Alarm_IRQHandler ; RTC Alarm (A and B) through EXTI Line
DCD OTG_FS_WKUP_IRQHandler ; USB OTG FS Wakeup through EXTI line
DCD TIM8_BRK_TIM12_IRQHandler ; TIM8 Break and TIM12
DCD TIM8_UP_TIM13_IRQHandler ; TIM8 Update and TIM13
DCD TIM8_TRG_COM_TIM14_IRQHandler ; TIM8 Trigger and Commutation and TIM14
DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare
DCD DMA1_Stream7_IRQHandler ; DMA1 Stream7
DCD FMC_IRQHandler ; FMC
DCD SDIO_IRQHandler ; SDIO
DCD TIM5_IRQHandler ; TIM5
DCD SPI3_IRQHandler ; SPI3
DCD UART4_IRQHandler ; UART4
DCD UART5_IRQHandler ; UART5
DCD TIM6_DAC_IRQHandler ; TIM6 and DAC1&2 underrun errors
DCD TIM7_IRQHandler ; TIM7
DCD DMA2_Stream0_IRQHandler ; DMA2 Stream 0
DCD DMA2_Stream1_IRQHandler ; DMA2 Stream 1
DCD DMA2_Stream2_IRQHandler ; DMA2 Stream 2
DCD DMA2_Stream3_IRQHandler ; DMA2 Stream 3
DCD DMA2_Stream4_IRQHandler ; DMA2 Stream 4
DCD ETH_IRQHandler ; Ethernet
DCD ETH_WKUP_IRQHandler ; Ethernet Wakeup through EXTI line
DCD CAN2_TX_IRQHandler ; CAN2 TX
DCD CAN2_RX0_IRQHandler ; CAN2 RX0
DCD CAN2_RX1_IRQHandler ; CAN2 RX1
DCD CAN2_SCE_IRQHandler ; CAN2 SCE
DCD OTG_FS_IRQHandler ; USB OTG FS
DCD DMA2_Stream5_IRQHandler ; DMA2 Stream 5
DCD DMA2_Stream6_IRQHandler ; DMA2 Stream 6
DCD DMA2_Stream7_IRQHandler ; DMA2 Stream 7
DCD USART6_IRQHandler ; USART6
DCD I2C3_EV_IRQHandler ; I2C3 event
DCD I2C3_ER_IRQHandler ; I2C3 error
DCD OTG_HS_EP1_OUT_IRQHandler ; USB OTG HS End Point 1 Out
DCD OTG_HS_EP1_IN_IRQHandler ; USB OTG HS End Point 1 In
DCD OTG_HS_WKUP_IRQHandler ; USB OTG HS Wakeup through EXTI
DCD OTG_HS_IRQHandler ; USB OTG HS
DCD DCMI_IRQHandler ; DCMI
DCD 0 ; Reserved
DCD HASH_RNG_IRQHandler ; Hash and Rng
DCD FPU_IRQHandler ; FPU
__Vectors_End//中斷向量表結束的位置
__Vectors_Size EQU __Vectors_End - __Vectors//計算得出中斷向量表的大小，賦值給__Vectors_Size
AREA |.text|, CODE, READONLY//定義代碼段,只讀
//復位中斷程序
Reset_Handler PROC//函數開始
EXPORT Reset_Handler [WEAK]//本函數外部可以應用，[WAKE]表示弱引用
IMPORT SystemInit//聲明使用外部函數SystemInit
IMPORT __main//聲明使用外部函數__main
LDR R0, =SystemInit//把函數地址賦值給寄存器R0
BLX R0//跳到R0地址處執行該地址上的函數SystemInit
LDR R0, =__main//把函數地址賦值給寄存器R0
BX R0//跳到R0地址處執行該地址上的函數__main
ENDP//函數結束
; Dummy Exception Handlers (infinite loops which can be modified)
/*下面的函數一樣，先聲明可以外部使用，然後B.相當於while(1)*/
NMI_Handler PROC
EXPORT NMI_Handler [WEAK]
B .
ENDP
HardFault_Handler\
PROC
EXPORT HardFault_Handler [WEAK]
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//函數開始
/*下面是中斷的函數，先把符號聲明爲外部可以用，[WEAK] 代表弱應用。表示如果外部有該標號有定義則使用外部的函數來表示真正的中斷處理函數*/
EXPORT WWDG_IRQHandler [WEAK]
EXPORT PVD_IRQHandler [WEAK]
EXPORT TAMP_STAMP_IRQHandler [WEAK]
EXPORT RTC_WKUP_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_Stream0_IRQHandler [WEAK]
EXPORT DMA1_Stream1_IRQHandler [WEAK]
EXPORT DMA1_Stream2_IRQHandler [WEAK]
EXPORT DMA1_Stream3_IRQHandler [WEAK]
EXPORT DMA1_Stream4_IRQHandler [WEAK]
EXPORT DMA1_Stream5_IRQHandler [WEAK]
EXPORT DMA1_Stream6_IRQHandler [WEAK]
EXPORT ADC_IRQHandler [WEAK]
EXPORT CAN1_TX_IRQHandler [WEAK]
EXPORT CAN1_RX0_IRQHandler [WEAK]
EXPORT CAN1_RX1_IRQHandler [WEAK]
EXPORT CAN1_SCE_IRQHandler [WEAK]
EXPORT EXTI9_5_IRQHandler [WEAK]
EXPORT TIM1_BRK_TIM9_IRQHandler [WEAK]
EXPORT TIM1_UP_TIM10_IRQHandler [WEAK]
EXPORT TIM1_TRG_COM_TIM11_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 RTC_Alarm_IRQHandler [WEAK]
EXPORT OTG_FS_WKUP_IRQHandler [WEAK]
EXPORT TIM8_BRK_TIM12_IRQHandler [WEAK]
EXPORT TIM8_UP_TIM13_IRQHandler [WEAK]
EXPORT TIM8_TRG_COM_TIM14_IRQHandler [WEAK]
EXPORT TIM8_CC_IRQHandler [WEAK]
EXPORT DMA1_Stream7_IRQHandler [WEAK]
EXPORT FMC_IRQHandler [WEAK]
EXPORT SDIO_IRQHandler [WEAK]
EXPORT TIM5_IRQHandler [WEAK]
EXPORT SPI3_IRQHandler [WEAK]
EXPORT UART4_IRQHandler [WEAK]
EXPORT UART5_IRQHandler [WEAK]
EXPORT TIM6_DAC_IRQHandler [WEAK]
EXPORT TIM7_IRQHandler [WEAK]
EXPORT DMA2_Stream0_IRQHandler [WEAK]
EXPORT DMA2_Stream1_IRQHandler [WEAK]
EXPORT DMA2_Stream2_IRQHandler [WEAK]
EXPORT DMA2_Stream3_IRQHandler [WEAK]
EXPORT DMA2_Stream4_IRQHandler [WEAK]
EXPORT ETH_IRQHandler [WEAK]
EXPORT ETH_WKUP_IRQHandler [WEAK]
EXPORT CAN2_TX_IRQHandler [WEAK]
EXPORT CAN2_RX0_IRQHandler [WEAK]
EXPORT CAN2_RX1_IRQHandler [WEAK]
EXPORT CAN2_SCE_IRQHandler [WEAK]
EXPORT OTG_FS_IRQHandler [WEAK]
EXPORT DMA2_Stream5_IRQHandler [WEAK]
EXPORT DMA2_Stream6_IRQHandler [WEAK]
EXPORT DMA2_Stream7_IRQHandler [WEAK]
EXPORT USART6_IRQHandler [WEAK]
EXPORT I2C3_EV_IRQHandler [WEAK]
EXPORT I2C3_ER_IRQHandler [WEAK]
EXPORT OTG_HS_EP1_OUT_IRQHandler [WEAK]
EXPORT OTG_HS_EP1_IN_IRQHandler [WEAK]
EXPORT OTG_HS_WKUP_IRQHandler [WEAK]
EXPORT OTG_HS_IRQHandler [WEAK]
EXPORT DCMI_IRQHandler [WEAK]
EXPORT HASH_RNG_IRQHandler [WEAK]
EXPORT FPU_IRQHandler [WEAK]
/*否則就使用下面的函數，來表示中斷處理函數，下面的函數都是空的，沒有任何有意義的執行指令，只會執行到B. 進入死循環中*/
WWDG_IRQHandler
PVD_IRQHandler
TAMP_STAMP_IRQHandler
RTC_WKUP_IRQHandler
FLASH_IRQHandler
RCC_IRQHandler
EXTI0_IRQHandler
EXTI1_IRQHandler
EXTI2_IRQHandler
EXTI3_IRQHandler
EXTI4_IRQHandler
DMA1_Stream0_IRQHandler
DMA1_Stream1_IRQHandler
DMA1_Stream2_IRQHandler
DMA1_Stream3_IRQHandler
DMA1_Stream4_IRQHandler
DMA1_Stream5_IRQHandler
DMA1_Stream6_IRQHandler
ADC_IRQHandler
CAN1_TX_IRQHandler
CAN1_RX0_IRQHandler
CAN1_RX1_IRQHandler
CAN1_SCE_IRQHandler
EXTI9_5_IRQHandler
TIM1_BRK_TIM9_IRQHandler
TIM1_UP_TIM10_IRQHandler
TIM1_TRG_COM_TIM11_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
RTC_Alarm_IRQHandler
OTG_FS_WKUP_IRQHandler
TIM8_BRK_TIM12_IRQHandler
TIM8_UP_TIM13_IRQHandler
TIM8_TRG_COM_TIM14_IRQHandler
TIM8_CC_IRQHandler
DMA1_Stream7_IRQHandler
FMC_IRQHandler
SDIO_IRQHandler
TIM5_IRQHandler
SPI3_IRQHandler
UART4_IRQHandler
UART5_IRQHandler
TIM6_DAC_IRQHandler
TIM7_IRQHandler
DMA2_Stream0_IRQHandler
DMA2_Stream1_IRQHandler
DMA2_Stream2_IRQHandler
DMA2_Stream3_IRQHandler
DMA2_Stream4_IRQHandler
ETH_IRQHandler
ETH_WKUP_IRQHandler
CAN2_TX_IRQHandler
CAN2_RX0_IRQHandler
CAN2_RX1_IRQHandler
CAN2_SCE_IRQHandler
OTG_FS_IRQHandler
DMA2_Stream5_IRQHandler
DMA2_Stream6_IRQHandler
DMA2_Stream7_IRQHandler
USART6_IRQHandler
I2C3_EV_IRQHandler
I2C3_ER_IRQHandler
OTG_HS_EP1_OUT_IRQHandler
OTG_HS_EP1_IN_IRQHandler
OTG_HS_WKUP_IRQHandler
OTG_HS_IRQHandler
DCMI_IRQHandler
HASH_RNG_IRQHandler
FPU_IRQHandler
B. //while(1)
ENDP//函數結束
ALIGN
;*******************************************************************************
; User Stack and Heap initialization
;*******************************************************************************
IF :DEF:__MICROLIB//如果定義了__MICROLIB，則爲真，否則爲假，目前未定義
//如果定義了，那麼下面棧定指針，堆起始地址，堆結束地址，可以由外部程序來使用，定義
EXPORT __initial_sp
EXPORT __heap_base
EXPORT __heap_limit
ELSE
IMPORT __use_two_region_memory//使用外部函數
EXPORT __user_initial_stackheap//聲明全局符號
__user_initial_stackheap
LDR R0, = Heap_Mem//堆的起始地址
LDR R1, =(Stack_Mem + Stack_Size)//棧的起始地址+棧的大小=棧的結束地址
LDR R2, = (Heap_Mem + Heap_Size)//堆的起始地址+堆的帶下=堆的結束地址
LDR R3, = Stack_Mem//棧起始的地址
BX LR//跳到返回地址執行
ALIGN
ENDIF
END
;************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE*****
stm32f407的有片內flash和ram， 那麼上面利用AREA 分配的區域，讀寫的一般位於RAM上，只讀一般位於flash上
STACK 段和HEAP段是讀寫，位於RAM上，RAM的起始是0x20000000
RSET段和 .text段是隻讀，位於flash上 lash的起始地址是0x08000000
通過這兩個圖可以看出，0x8000000放的是RESET
通過這個圖可以看出STACK 段和HEAP位於0x2000000的位置
總結：STM32啓動文件，首先定義了棧和堆的大小，並在代碼區定義中斷向量表，表中第一個是棧頂地址，第二個是復位中段的程序的入口，Reset_Handler是系統上電後自動跳轉至該處，然後開始執行其後的相關代碼，其中_main並非C中的main函數，而是C庫函數，其會初始化棧、堆，配置系統環境，在函數的最後調用用戶編寫的main函數，進入C的世界。
用戶堆棧初始化由C庫函數__main完成，__MICROLIB由KEIL裏面開啓，__use_two_region_memory由用戶自己實現。
一般而言，系統上電後第一個執行的是由彙編所編寫的啓動文件，其主要工作爲一下五部分：
（1）、初始化堆棧指針SP=_initial_sp
（2）、初始化PC指針，令其=Reset_Handler
（3）、初始化中斷向量表
（4）、配置系統時鐘 //位於system_stm32f4xx.c中的SystemInit（）
（5）、調用C庫函數_main初始化用戶堆棧，從而最終調用main函數進入C的世界