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STM32 keil mdk启动代码发分析

2014-02-20 16:56 302 查看

学习STM32,看了一堆乱七八糟的文档,准备写程序了,先分析了下STM32的启动代码,看着这堆鬼鬼的汇编代码,挺吓人的,看看帮助,查查网路,还是不那么难懂。

[c-sharp]
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;// <h> Stack Configuration  
;//   <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>  
;// </h>  
Stack_Size      EQU     0x00000200                           ;//定义堆栈大小  
                AREA    STACK, NOINIT, READWRITE, ALIGN=3    ;//定义一个数据段 按8字节对齐  
Stack_Mem       SPACE   Stack_Size                           ;//保留Stack_Size大小的堆栈空间  
__initial_sp                                                 ;//标号,代表堆栈顶部地址,后面有用  
  
;// <h> Heap Configuration  
;//   <o>  Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>  
;// </h>  
Heap_Size       EQU     0x00000020                            ;//定义堆空间大小  
                AREA    HEAP, NOINIT, READWRITE, ALIGN=3      ;//定义一个数据段,8字节对齐  
__heap_base  
Heap_Mem        SPACE   Heap_Size                             ;//保留Heap_Size的堆空间  
__heap_limit                                                  ;//标号,代表堆末尾地址,后面有用  
  
                PRESERVE8                                     ;//指示编译器8字节对齐  
                THUMB                                         ;//指示编译器为THUMB指令  
  
; Vector Table Mapped to Address 0 at Reset  
                AREA    RESET, DATA, READONLY                  ;//定义只读数据段,其实放在CODE区,位于0地址  
                  
                EXTERN  NMIException  
                EXTERN  HardFaultException  
                EXTERN  MemManageException  
                EXTERN  BusFaultException  
                EXTERN  UsageFaultException  
                EXTERN  SVCHandler  
                EXTERN  DebugMonitor  
                EXTERN  PendSVC  
                EXTERN  SysTickHandler                         ;//声明这些符号在外部定义,同C  
                                                               ;//在××it.c中实现这些函数 ,中断就能自动调用了  
                EXPORT  __Vectors  
__Vectors       DCD     __initial_sp              ; Top of Stack         //Cotex-M  要求此处为堆栈顶部地址  
                DCD     Reset_Handler             ; Reset Handler  
                DCD     NMIException              ; NMI Handler  
                DCD     HardFaultException        ; Hard Fault Handler  
                DCD     MemManageException        ; MPU Fault Handler  
                DCD     BusFaultException         ; Bus Fault Handler  
                DCD     UsageFaultException       ; Usage Fault Handler  
                DCD     0                         ; Reserved  
                DCD     0                         ; Reserved  
                DCD     0                         ; Reserved  
                DCD     0                         ; Reserved  
                DCD     SVCHandler                ; SVCall Handler  
                DCD     DebugMonitor              ; Debug Monitor Handler  
                DCD     0                         ; Reserved  
                DCD     PendSVC                   ; PendSV Handler  
                DCD     SysTickHandler            ; SysTick Handler      //一大堆的异常处理函数地址  
                ; External Interrupts  
                EXTERN  WWDG_IRQHandler  
                EXTERN  PVD_IRQHandler  
                EXTERN  TAMPER_IRQHandler  
                EXTERN  RTC_IRQHandler  
                EXTERN  FLASH_IRQHandler  
                EXTERN  RCC_IRQHandler  
                EXTERN  EXTI0_IRQHandler  
                EXTERN  EXTI1_IRQHandler  
                EXTERN  EXTI2_IRQHandler  
                EXTERN  EXTI3_IRQHandler  
                EXTERN  EXTI4_IRQHandler  
                EXTERN  DMAChannel1_IRQHandler  
                EXTERN  DMAChannel2_IRQHandler  
                EXTERN  DMAChannel3_IRQHandler  
                EXTERN  DMAChannel4_IRQHandler  
                EXTERN  DMAChannel5_IRQHandler  
                EXTERN  DMAChannel6_IRQHandler  
                EXTERN  DMAChannel7_IRQHandler  
                EXTERN  ADC_IRQHandler  
                EXTERN  USB_HP_CAN_TX_IRQHandler  
                EXTERN  USB_LP_CAN_RX0_IRQHandler  
                EXTERN  CAN_RX1_IRQHandler  
                EXTERN  CAN_SCE_IRQHandler  
                EXTERN  EXTI9_5_IRQHandler  
                EXTERN  TIM1_BRK_IRQHandler  
                EXTERN  TIM1_UP_IRQHandler  
                EXTERN  TIM1_TRG_COM_IRQHandler  
                EXTERN  TIM1_CC_IRQHandler  
                EXTERN  TIM2_IRQHandler  
                EXTERN  TIM3_IRQHandler  
                EXTERN  TIM4_IRQHandler  
                EXTERN  I2C1_EV_IRQHandler  
                EXTERN  I2C1_ER_IRQHandler  
                EXTERN  I2C2_EV_IRQHandler  
                EXTERN  I2C2_ER_IRQHandler  
                EXTERN  SPI1_IRQHandler  
                EXTERN  SPI2_IRQHandler  
                EXTERN  USART1_IRQHandler  
                EXTERN  USART2_IRQHandler  
                EXTERN  USART3_IRQHandler  
                EXTERN  EXTI15_10_IRQHandler  
                EXTERN  RTCAlarm_IRQHandler  
                EXTERN  USBWakeUp_IRQHandler                    ;//同上,  
                  
                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     DMAChannel1_IRQHandler    ; DMA Channel 1  
                DCD     DMAChannel2_IRQHandler    ; DMA Channel 2  
                DCD     DMAChannel3_IRQHandler    ; DMA Channel 3  
                DCD     DMAChannel4_IRQHandler    ; DMA Channel 4  
                DCD     DMAChannel5_IRQHandler    ; DMA Channel 5  
                DCD     DMAChannel6_IRQHandler    ; DMA Channel 6  
                DCD     DMAChannel7_IRQHandler    ; DMA Channel 7  
                DCD     ADC_IRQHandler            ; ADC  
                DCD     USB_HP_CAN_TX_IRQHandler  ; USB High Priority or CAN TX  
                DCD     USB_LP_CAN_RX0_IRQHandler ; USB Low  Priority or CAN RX0  
                DCD     CAN_RX1_IRQHandler        ; CAN RX1  
                DCD     CAN_SCE_IRQHandler        ; CAN 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   ;//同上  
  
                AREA    |.text|, CODE, READONLY        ;//定义代码段  
  
; Reset Handler  
Reset_Handler   PROC                                        ;//Rset_Handler的实现  
                EXPORT  Reset_Handler             [WEAK]    ;//在外部没有定义该符号时导出该符号,见HELP中[WEAK]  
                IMPORT  __main                              ;//导入符号,__main为 运行时库提供的函数;完成堆栈,堆的初始话  
                LDR     R0, =__main                         ;//等工作,会调用下面定义的__user_initial_stackheap;  
                BX      R0                                  ;//跳到__main,进入C的世界  
                ENDP  
  
                ALIGN  
  
; User Initial Stack & Heap  
                IF      :DEF:__MICROLIB                     ;//如果使用micro lib,micro lib 描述见armlib.chm  
                  
                EXPORT  __initial_sp  
                EXPORT  __heap_base  
                EXPORT  __heap_limit                        ;//只导出几个定义  
                  
                ELSE                                        ;//如果使用默认C运行时库  
                  
                IMPORT  __use_two_region_memory  
                EXPORT  __user_initial_stackheap  
__user_initial_stackheap                                    ;//则进行堆栈和堆的赋值,在__main函数执行过程中调用。  
                LDR     R0, =  Heap_Mem  
                LDR     R1, =(Stack_Mem + Stack_Size)  
                LDR     R2, = (Heap_Mem +  Heap_Size)  
                LDR     R3, = Stack_Mem  
                BX      LR  
                ALIGN  
                ENDIF  
  
                END                                         ;//OK ,完了 
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