STM32 keil mdk 启动代码分析
  1 ;// <h> Stack Configuration  
  2 ;//   <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>  
  3 ;// </h>  
  4 Stack_Size      EQU     0x00000200                           ;//定义堆栈大小  
  5                 AREA    STACK, NOINIT, READWRITE, ALIGN=3    ;//定义一个数据段 按8字节对齐  
  6 Stack_Mem       SPACE   Stack_Size                           ;//保留Stack_Size大小的堆栈空间  
  7 __initial_sp                                                 ;//标号,代表堆栈顶部地址,后面有用  
  8   
  9 ;// <h> Heap Configuration  
 10 ;//   <o>  Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>  
 11 ;// </h>  
 12 Heap_Size       EQU     0x00000020                            ;//定义堆空间大小  
 13                 AREA    HEAP, NOINIT, READWRITE, ALIGN=3      ;//定义一个数据段,8字节对齐  
 14 __heap_base  
 15 Heap_Mem        SPACE   Heap_Size                             ;//保留Heap_Size的堆空间  
 16 __heap_limit                                                  ;//标号,代表堆末尾地址,后面有用  
 17   
 18                 PRESERVE8                                     ;//指示编译器8字节对齐  
 19                 THUMB                                         ;//指示编译器为THUMB指令  
 20   
 21 ; Vector Table Mapped to Address 0 at Reset  
 22                 AREA    RESET, DATA, READONLY                  ;//定义只读数据段,其实放在CODE区,位于0地址  
 23                   
 24                 EXTERN  NMIException  
 25                 EXTERN  HardFaultException  
 26                 EXTERN  MemManageException  
 27                 EXTERN  BusFaultException  
 28                 EXTERN  UsageFaultException  
 29                 EXTERN  SVCHandler  
 30                 EXTERN  DebugMonitor  
 31                 EXTERN  PendSVC  
 32                 EXTERN  SysTickHandler                         ;//声明这些符号在外部定义,同C  
 33                                                                ;//在××it.c中实现这些函数 ,中断就能自动调用了  
 34                 EXPORT  __Vectors  
 35 __Vectors       DCD     __initial_sp              ; Top of Stack         //Cotex-M  要求此处为堆栈顶部地址  
 36                 DCD     Reset_Handler             ; Reset Handler  
 37                 DCD     NMIException              ; NMI Handler  
 38                 DCD     HardFaultException        ; Hard Fault Handler  
 39                 DCD     MemManageException        ; MPU Fault Handler  
 40                 DCD     BusFaultException         ; Bus Fault Handler  
 41                 DCD     UsageFaultException       ; Usage Fault Handler  
 42                 DCD     0                         ; Reserved  
 43                 DCD     0                         ; Reserved  
 44                 DCD     0                         ; Reserved  
 45                 DCD     0                         ; Reserved  
 46                 DCD     SVCHandler                ; SVCall Handler  
 47                 DCD     DebugMonitor              ; Debug Monitor Handler  
 48                 DCD     0                         ; Reserved  
 49                 DCD     PendSVC                   ; PendSV Handler  
 50                 DCD     SysTickHandler            ; SysTick Handler      //一大堆的异常处理函数地址  
 51                 ; External Interrupts  
 52                 EXTERN  WWDG_IRQHandler  
 53                 EXTERN  PVD_IRQHandler  
 54                 EXTERN  TAMPER_IRQHandler  
 55                 EXTERN  RTC_IRQHandler  
 56                 EXTERN  FLASH_IRQHandler  
 57                 EXTERN  RCC_IRQHandler  
 58                 EXTERN  EXTI0_IRQHandler  
 59                 EXTERN  EXTI1_IRQHandler  
 60                 EXTERN  EXTI2_IRQHandler  
 61                 EXTERN  EXTI3_IRQHandler  
 62                 EXTERN  EXTI4_IRQHandler  
 63                 EXTERN  DMAChannel1_IRQHandler  
 64                 EXTERN  DMAChannel2_IRQHandler  
 65                 EXTERN  DMAChannel3_IRQHandler  
 66                 EXTERN  DMAChannel4_IRQHandler  
 67                 EXTERN  DMAChannel5_IRQHandler  
 68                 EXTERN  DMAChannel6_IRQHandler  
 69                 EXTERN  DMAChannel7_IRQHandler  
 70                 EXTERN  ADC_IRQHandler  
 71                 EXTERN  USB_HP_CAN_TX_IRQHandler  
 72                 EXTERN  USB_LP_CAN_RX0_IRQHandler  
 73                 EXTERN  CAN_RX1_IRQHandler  
 74                 EXTERN  CAN_SCE_IRQHandler  
 75                 EXTERN  EXTI9_5_IRQHandler  
 76                 EXTERN  TIM1_BRK_IRQHandler  
 77                 EXTERN  TIM1_UP_IRQHandler  
 78                 EXTERN  TIM1_TRG_COM_IRQHandler  
 79                 EXTERN  TIM1_CC_IRQHandler  
 80                 EXTERN  TIM2_IRQHandler  
 81                 EXTERN  TIM3_IRQHandler  
 82                 EXTERN  TIM4_IRQHandler  
 83                 EXTERN  I2C1_EV_IRQHandler  
 84                 EXTERN  I2C1_ER_IRQHandler  
 85                 EXTERN  I2C2_EV_IRQHandler  
 86                 EXTERN  I2C2_ER_IRQHandler  
 87                 EXTERN  SPI1_IRQHandler  
 88                 EXTERN  SPI2_IRQHandler  
 89                 EXTERN  USART1_IRQHandler  
 90                 EXTERN  USART2_IRQHandler  
 91                 EXTERN  USART3_IRQHandler  
 92                 EXTERN  EXTI15_10_IRQHandler  
 93                 EXTERN  RTCAlarm_IRQHandler  
 94                 EXTERN  USBWakeUp_IRQHandler                    ;//同上,  
 95                   
 96                 DCD     WWDG_IRQHandler           ; Window Watchdog  
 97                 DCD     PVD_IRQHandler            ; PVD through EXTI Line detect  
 98                 DCD     TAMPER_IRQHandler         ; Tamper  
 99                 DCD     RTC_IRQHandler            ; RTC  
100                 DCD     FLASH_IRQHandler          ; Flash  
101                 DCD     RCC_IRQHandler            ; RCC  
102                 DCD     EXTI0_IRQHandler          ; EXTI Line 0  
103                 DCD     EXTI1_IRQHandler          ; EXTI Line 1  
104                 DCD     EXTI2_IRQHandler          ; EXTI Line 2  
105                 DCD     EXTI3_IRQHandler          ; EXTI Line 3  
106                 DCD     EXTI4_IRQHandler          ; EXTI Line 4  
107                 DCD     DMAChannel1_IRQHandler    ; DMA Channel 1  
108                 DCD     DMAChannel2_IRQHandler    ; DMA Channel 2  
109                 DCD     DMAChannel3_IRQHandler    ; DMA Channel 3  
110                 DCD     DMAChannel4_IRQHandler    ; DMA Channel 4  
111                 DCD     DMAChannel5_IRQHandler    ; DMA Channel 5  
112                 DCD     DMAChannel6_IRQHandler    ; DMA Channel 6  
113                 DCD     DMAChannel7_IRQHandler    ; DMA Channel 7  
114                 DCD     ADC_IRQHandler            ; ADC  
115                 DCD     USB_HP_CAN_TX_IRQHandler  ; USB High Priority or CAN TX  
116                 DCD     USB_LP_CAN_RX0_IRQHandler ; USB Low  Priority or CAN RX0  
117                 DCD     CAN_RX1_IRQHandler        ; CAN RX1  
118                 DCD     CAN_SCE_IRQHandler        ; CAN SCE  
119                 DCD     EXTI9_5_IRQHandler        ; EXTI Line 9..5  
120                 DCD     TIM1_BRK_IRQHandler       ; TIM1 Break  
121                 DCD     TIM1_UP_IRQHandler        ; TIM1 Update  
122                 DCD     TIM1_TRG_COM_IRQHandler   ; TIM1 Trigger and Commutation  
123                 DCD     TIM1_CC_IRQHandler        ; TIM1 Capture Compare  
124                 DCD     TIM2_IRQHandler           ; TIM2  
125                 DCD     TIM3_IRQHandler           ; TIM3  
126                 DCD     TIM4_IRQHandler           ; TIM4  
127                 DCD     I2C1_EV_IRQHandler        ; I2C1 Event  
128                 DCD     I2C1_ER_IRQHandler        ; I2C1 Error  
129                 DCD     I2C2_EV_IRQHandler        ; I2C2 Event  
130                 DCD     I2C2_ER_IRQHandler        ; I2C2 Error  
131                 DCD     SPI1_IRQHandler           ; SPI1  
132                 DCD     SPI2_IRQHandler           ; SPI2  
133                 DCD     USART1_IRQHandler         ; USART1  
134                 DCD     USART2_IRQHandler         ; USART2  
135                 DCD     USART3_IRQHandler         ; USART3  
136                 DCD     EXTI15_10_IRQHandler      ; EXTI Line 15..10  
137                 DCD     RTCAlarm_IRQHandler       ; RTC Alarm through EXTI Line  
138                 DCD     USBWakeUp_IRQHandler      ; USB Wakeup from suspend   ;//同上  
139   
140                 AREA    |.text|, CODE, READONLY        ;//定义代码段  
141   
142 ; Reset Handler  
143 Reset_Handler   PROC                                        ;//Rset_Handler的实现  
144                 EXPORT  Reset_Handler             [WEAK]    ;//在外部没有定义该符号时导出该符号,见HELP中[WEAK]  
145                 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  
146                 LDR     R0, =__main                         ;//等工作,会调用下面定义的__user_initial_stackheap;  
147                 BX      R0                                  ;//跳到__main,进入C的世界  
148                 ENDP  
149   
150                 ALIGN  
151   
152 ; User Initial Stack & Heap  
153                 IF      :DEF:__MICROLIB                     ;//如果使用micro lib,micro lib 描述见armlib.chm  
154                   
155                 EXPORT  __initial_sp  
156                 EXPORT  __heap_base  
157                 EXPORT  __heap_limit                        ;//只导出几个定义  
158                   
159                 ELSE                                        ;//如果使用默认C运行时库  
160                   
161                 IMPORT  __use_two_region_memory  
162                 EXPORT  __user_initial_stackheap  
163 __user_initial_stackheap                                    ;//则进行堆栈和堆的赋值,在__main函数执行过程中调用。  
164                 LDR     R0, =  Heap_Mem  
165                 LDR     R1, =(Stack_Mem + Stack_Size)  
166                 LDR     R2, = (Heap_Mem +  Heap_Size)  
167                 LDR     R3, = Stack_Mem  
168                 BX      LR  
169                 ALIGN  
170                 ENDIF  
171   
172                 END                                         ;//OK ,完了