关于 startup_stm32f10x_hd.s 这个文件的一些说明
startup_stm32f10x_hd.s 是一个启动文件，里面是使用汇编语言写好的基本程序，当STM32 芯片上电启动的时候，受限会执行这里的汇编程序，从而建立起来C 语言的运行环境，所以我们把这个文件称为启动文件。改文件使用的汇编指令是 Cortex-M3 内核支持的指令，可以参考《Cortex-M3 权威指南中文》内指令集章节。
startup_stm32f10x_hd.s 文件是由ST官方提供的，该文件可以从KEIL5 安装目录中找到，也可以从ST库里面找到，找到该文件后吧启动文件添加到工程里面即可。不同型号的芯片以及不同编译环境使用的汇编文件是不一样的，但功能相同。
对于启动文件部分，我们主要总结功能，主要功能如下：
- 初始化堆栈指针 SP
- 初始化程序计数器指针 PC
- 设置堆、栈的大小
- 设置中断向量表的入口地址
- 配置外部 SRAM 作为数据存储器
- 调用 SystemInit() 函数配置 STM32 的系统时钟
- 设置 C 库的分支入口 "__main” (最终用来调用 main 函数)
Reset_Hander
1 ; Reset handler ; 汇编里面注释用的是";"，相当于 C 语言的 “//” 注释符 2 Reset_Handler PROC ;PROC 是子程序定义伪指令。这里相当于 C 语言定义了一个函数为 Reset_Handler 3 EXPORT Reset_Handler [WEAK] ;EXPORT 表示 Reset_Handler 这个子程序可供其他模块调用，相当于C的函数声明;[WEAK]表示弱定义 4 IMPORT __main ;IMPORT 说明 __main 这个标号在其他文件，在链接时候需去其他文件中寻找。相当于c中引入函数声明 5 IMPORT SystemInit 6 LDR R0, =SystemInit ;把 SystemInit 的地址加载到寄存器 R0 中 7 BLX R0 ;程序跳转到 R0 中地址执行程序，即执行 SystemInit 函数内容 8 LDR R0, =__main ;把 __main 的地址加载到寄存器 R0 9 BX R0 ;程序跳转到 R0 中地址执行程序，即执行 __main 函数，执行完毕后即可进入 main 函数 10 ENDP
下面是 startup_stm32f10x_hd.s 源代码
1 ;******************** (C) COPYRIGHT 2011 STMicroelectronics ******************** 2 ;* File Name : startup_stm32f10x_hd.s 3 ;* Author : MCD Application Team 4 ;* Version : V3.5.0 5 ;* Date : 11-March-2011 6 ;* Description : STM32F10x High Density Devices vector table for MDK-ARM 7 ;* toolchain. 8 ;* This module performs: 9 ;* - Set the initial SP 10 ;* - Set the initial PC == Reset_Handler 11 ;* - Set the vector table entries with the exceptions ISR address 12 ;* - Configure the clock system and also configure the external 13 ;* SRAM mounted on STM3210E-EVAL board to be used as data 14 ;* memory (optional, to be enabled by user) 15 ;* - Branches to __main in the C library (which eventually 16 ;* calls main()). 17 ;* After Reset the CortexM3 processor is in Thread mode, 18 ;* priority is Privileged, and the Stack is set to Main. 19 ;* <<< Use Configuration Wizard in Context Menu >>> 20 ;******************************************************************************* 21 ; THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS 22 ; WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME. 23 ; AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY DIRECT, 24 ; INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE 25 ; CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING 26 ; INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS. 27 ;******************************************************************************* 28 29 ; Amount of memory (in bytes) allocated for Stack 30 ; Tailor this value to your application needs 31 ; <h> Stack Configuration 32 ; <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8> 33 ; </h> 34 35 Stack_Size EQU 0x00000400 36 37 AREA STACK, NOINIT, READWRITE, ALIGN=3 38 Stack_Mem SPACE Stack_Size 39 __initial_sp 40 41 ; <h> Heap Configuration 42 ; <o> Heap Size (in Bytes) <0x0-0xFFFFFFFF:8> 43 ; </h> 44 45 Heap_Size EQU 0x00000200 46 47 AREA HEAP, NOINIT, READWRITE, ALIGN=3 48 __heap_base 49 Heap_Mem SPACE Heap_Size 50 __heap_limit 51 52 PRESERVE8 53 THUMB 54 55 56 ; Vector Table Mapped to Address 0 at Reset 57 AREA RESET, DATA, READONLY 58 EXPORT __Vectors 59 EXPORT __Vectors_End 60 EXPORT __Vectors_Size 61 62 __Vectors DCD __initial_sp ; Top of Stack 63 DCD Reset_Handler ; Reset Handler 64 DCD NMI_Handler ; NMI Handler 65 DCD HardFault_Handler ; Hard Fault Handler 66 DCD MemManage_Handler ; MPU Fault Handler 67 DCD BusFault_Handler ; Bus Fault Handler 68 DCD UsageFault_Handler ; Usage Fault Handler 69 DCD 0 ; Reserved 70 DCD 0 ; Reserved 71 DCD 0 ; Reserved 72 DCD 0 ; Reserved 73 DCD SVC_Handler ; SVCall Handler 74 DCD DebugMon_Handler ; Debug Monitor Handler 75 DCD 0 ; Reserved 76 DCD PendSV_Handler ; PendSV Handler 77 DCD SysTick_Handler ; SysTick Handler 78 79 ; External Interrupts 80 DCD WWDG_IRQHandler ; Window Watchdog 81 DCD PVD_IRQHandler ; PVD through EXTI Line detect 82 DCD TAMPER_IRQHandler ; Tamper 83 DCD RTC_IRQHandler ; RTC 84 DCD FLASH_IRQHandler ; Flash 85 DCD RCC_IRQHandler ; RCC 86 DCD EXTI0_IRQHandler ; EXTI Line 0 87 DCD EXTI1_IRQHandler ; EXTI Line 1 88 DCD EXTI2_IRQHandler ; EXTI Line 2 89 DCD EXTI3_IRQHandler ; EXTI Line 3 90 DCD EXTI4_IRQHandler ; EXTI Line 4 91 DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1 92 DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2 93 DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3 94 DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4 95 DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5 96 DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6 97 DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7 98 DCD ADC1_2_IRQHandler ; ADC1 & ADC2 99 DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TX 100 DCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0 101 DCD CAN1_RX1_IRQHandler ; CAN1 RX1 102 DCD CAN1_SCE_IRQHandler ; CAN1 SCE 103 DCD EXTI9_5_IRQHandler ; EXTI Line 9..5 104 DCD TIM1_BRK_IRQHandler ; TIM1 Break 105 DCD TIM1_UP_IRQHandler ; TIM1 Update 106 DCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and Commutation 107 DCD TIM1_CC_IRQHandler ; TIM1 Capture Compare 108 DCD TIM2_IRQHandler ; TIM2 109 DCD TIM3_IRQHandler ; TIM3 110 DCD TIM4_IRQHandler ; TIM4 111 DCD I2C1_EV_IRQHandler ; I2C1 Event 112 DCD I2C1_ER_IRQHandler ; I2C1 Error 113 DCD I2C2_EV_IRQHandler ; I2C2 Event 114 DCD I2C2_ER_IRQHandler ; I2C2 Error 115 DCD SPI1_IRQHandler ; SPI1 116 DCD SPI2_IRQHandler ; SPI2 117 DCD USART1_IRQHandler ; USART1 118 DCD USART2_IRQHandler ; USART2 119 DCD USART3_IRQHandler ; USART3 120 DCD EXTI15_10_IRQHandler ; EXTI Line 15..10 121 DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI Line 122 DCD USBWakeUp_IRQHandler ; USB Wakeup from suspend 123 DCD TIM8_BRK_IRQHandler ; TIM8 Break 124 DCD TIM8_UP_IRQHandler ; TIM8 Update 125 DCD TIM8_TRG_COM_IRQHandler ; TIM8 Trigger and Commutation 126 DCD TIM8_CC_IRQHandler ; TIM8 Capture Compare 127 DCD ADC3_IRQHandler ; ADC3 128 DCD FSMC_IRQHandler ; FSMC 129 DCD SDIO_IRQHandler ; SDIO 130 DCD TIM5_IRQHandler ; TIM5 131 DCD SPI3_IRQHandler ; SPI3 132 DCD UART4_IRQHandler ; UART4 133 DCD UART5_IRQHandler ; UART5 134 DCD TIM6_IRQHandler ; TIM6 135 DCD TIM7_IRQHandler ; TIM7 136 DCD DMA2_Channel1_IRQHandler ; DMA2 Channel1 137 DCD DMA2_Channel2_IRQHandler ; DMA2 Channel2 138 DCD DMA2_Channel3_IRQHandler ; DMA2 Channel3 139 DCD DMA2_Channel4_5_IRQHandler ; DMA2 Channel4 & Channel5 140 __Vectors_End 141 142 __Vectors_Size EQU __Vectors_End - __Vectors 143 144 AREA |.text|, CODE, READONLY 145 146 ; Reset handler 147 Reset_Handler PROC 148 EXPORT Reset_Handler [WEAK] 149 IMPORT __main 150 IMPORT SystemInit 151 LDR R0, =SystemInit 152 BLX R0 153 LDR R0, =__main 154 BX R0 155 ENDP 156 157 ; Dummy Exception Handlers (infinite loops which can be modified) 158 159 NMI_Handler PROC 160 EXPORT NMI_Handler [WEAK] 161 B . 162 ENDP 163 HardFault_Handler 164 PROC 165 EXPORT HardFault_Handler [WEAK] 166 B . 167 ENDP 168 MemManage_Handler 169 PROC 170 EXPORT MemManage_Handler [WEAK] 171 B . 172 ENDP 173 BusFault_Handler 174 PROC 175 EXPORT BusFault_Handler [WEAK] 176 B . 177 ENDP 178 UsageFault_Handler 179 PROC 180 EXPORT UsageFault_Handler [WEAK] 181 B . 182 ENDP 183 SVC_Handler PROC 184 EXPORT SVC_Handler [WEAK] 185 B . 186 ENDP 187 DebugMon_Handler 188 PROC 189 EXPORT DebugMon_Handler [WEAK] 190 B . 191 ENDP 192 PendSV_Handler PROC 193 EXPORT PendSV_Handler [WEAK] 194 B . 195 ENDP 196 SysTick_Handler PROC 197 EXPORT SysTick_Handler [WEAK] 198 B . 199 ENDP 200 201 Default_Handler PROC 202 203 EXPORT WWDG_IRQHandler [WEAK] 204 EXPORT PVD_IRQHandler [WEAK] 205 EXPORT TAMPER_IRQHandler [WEAK] 206 EXPORT RTC_IRQHandler [WEAK] 207 EXPORT FLASH_IRQHandler [WEAK] 208 EXPORT RCC_IRQHandler [WEAK] 209 EXPORT EXTI0_IRQHandler [WEAK] 210 EXPORT EXTI1_IRQHandler [WEAK] 211 EXPORT EXTI2_IRQHandler [WEAK] 212 EXPORT EXTI3_IRQHandler [WEAK] 213 EXPORT EXTI4_IRQHandler [WEAK] 214 EXPORT DMA1_Channel1_IRQHandler [WEAK] 215 EXPORT DMA1_Channel2_IRQHandler [WEAK] 216 EXPORT DMA1_Channel3_IRQHandler [WEAK] 217 EXPORT DMA1_Channel4_IRQHandler [WEAK] 218 EXPORT DMA1_Channel5_IRQHandler [WEAK] 219 EXPORT DMA1_Channel6_IRQHandler [WEAK] 220 EXPORT DMA1_Channel7_IRQHandler [WEAK] 221 EXPORT ADC1_2_IRQHandler [WEAK] 222 EXPORT USB_HP_CAN1_TX_IRQHandler [WEAK] 223 EXPORT USB_LP_CAN1_RX0_IRQHandler [WEAK] 224 EXPORT CAN1_RX1_IRQHandler [WEAK] 225 EXPORT CAN1_SCE_IRQHandler [WEAK] 226 EXPORT EXTI9_5_IRQHandler [WEAK] 227 EXPORT TIM1_BRK_IRQHandler [WEAK] 228 EXPORT TIM1_UP_IRQHandler [WEAK] 229 EXPORT TIM1_TRG_COM_IRQHandler [WEAK] 230 EXPORT TIM1_CC_IRQHandler [WEAK] 231 EXPORT TIM2_IRQHandler [WEAK] 232 EXPORT TIM3_IRQHandler [WEAK] 233 EXPORT TIM4_IRQHandler [WEAK] 234 EXPORT I2C1_EV_IRQHandler [WEAK] 235 EXPORT I2C1_ER_IRQHandler [WEAK] 236 EXPORT I2C2_EV_IRQHandler [WEAK] 237 EXPORT I2C2_ER_IRQHandler [WEAK] 238 EXPORT SPI1_IRQHandler [WEAK] 239 EXPORT SPI2_IRQHandler [WEAK] 240 EXPORT USART1_IRQHandler [WEAK] 241 EXPORT USART2_IRQHandler [WEAK] 242 EXPORT USART3_IRQHandler [WEAK] 243 EXPORT EXTI15_10_IRQHandler [WEAK] 244 EXPORT RTCAlarm_IRQHandler [WEAK] 245 EXPORT USBWakeUp_IRQHandler [WEAK] 246 EXPORT TIM8_BRK_IRQHandler [WEAK] 247 EXPORT TIM8_UP_IRQHandler [WEAK] 248 EXPORT TIM8_TRG_COM_IRQHandler [WEAK] 249 EXPORT TIM8_CC_IRQHandler [WEAK] 250 EXPORT ADC3_IRQHandler [WEAK] 251 EXPORT FSMC_IRQHandler [WEAK] 252 EXPORT SDIO_IRQHandler [WEAK] 253 EXPORT TIM5_IRQHandler [WEAK] 254 EXPORT SPI3_IRQHandler [WEAK] 255 EXPORT UART4_IRQHandler [WEAK] 256 EXPORT UART5_IRQHandler [WEAK] 257 EXPORT TIM6_IRQHandler [WEAK] 258 EXPORT TIM7_IRQHandler [WEAK] 259 EXPORT DMA2_Channel1_IRQHandler [WEAK] 260 EXPORT DMA2_Channel2_IRQHandler [WEAK] 261 EXPORT DMA2_Channel3_IRQHandler [WEAK] 262 EXPORT DMA2_Channel4_5_IRQHandler [WEAK] 263 264 WWDG_IRQHandler 265 PVD_IRQHandler 266 TAMPER_IRQHandler 267 RTC_IRQHandler 268 FLASH_IRQHandler 269 RCC_IRQHandler 270 EXTI0_IRQHandler 271 EXTI1_IRQHandler 272 EXTI2_IRQHandler 273 EXTI3_IRQHandler 274 EXTI4_IRQHandler 275 DMA1_Channel1_IRQHandler 276 DMA1_Channel2_IRQHandler 277 DMA1_Channel3_IRQHandler 278 DMA1_Channel4_IRQHandler 279 DMA1_Channel5_IRQHandler 280 DMA1_Channel6_IRQHandler 281 DMA1_Channel7_IRQHandler 282 ADC1_2_IRQHandler 283 USB_HP_CAN1_TX_IRQHandler 284 USB_LP_CAN1_RX0_IRQHandler 285 CAN1_RX1_IRQHandler 286 CAN1_SCE_IRQHandler 287 EXTI9_5_IRQHandler 288 TIM1_BRK_IRQHandler 289 TIM1_UP_IRQHandler 290 TIM1_TRG_COM_IRQHandler 291 TIM1_CC_IRQHandler 292 TIM2_IRQHandler 293 TIM3_IRQHandler 294 TIM4_IRQHandler 295 I2C1_EV_IRQHandler 296 I2C1_ER_IRQHandler 297 I2C2_EV_IRQHandler 298 I2C2_ER_IRQHandler 299 SPI1_IRQHandler 300 SPI2_IRQHandler 301 USART1_IRQHandler 302 USART2_IRQHandler 303 USART3_IRQHandler 304 EXTI15_10_IRQHandler 305 RTCAlarm_IRQHandler 306 USBWakeUp_IRQHandler 307 TIM8_BRK_IRQHandler 308 TIM8_UP_IRQHandler 309 TIM8_TRG_COM_IRQHandler 310 TIM8_CC_IRQHandler 311 ADC3_IRQHandler 312 FSMC_IRQHandler 313 SDIO_IRQHandler 314 TIM5_IRQHandler 315 SPI3_IRQHandler 316 UART4_IRQHandler 317 UART5_IRQHandler 318 TIM6_IRQHandler 319 TIM7_IRQHandler 320 DMA2_Channel1_IRQHandler 321 DMA2_Channel2_IRQHandler 322 DMA2_Channel3_IRQHandler 323 DMA2_Channel4_5_IRQHandler 324 B . 325 326 ENDP 327 328 ALIGN 329 330 ;******************************************************************************* 331 ; User Stack and Heap initialization 332 ;******************************************************************************* 333 IF :DEF:__MICROLIB 334 335 EXPORT __initial_sp 336 EXPORT __heap_base 337 EXPORT __heap_limit 338 339 ELSE 340 341 IMPORT __use_two_region_memory 342 EXPORT __user_initial_stackheap 343 344 __user_initial_stackheap 345 346 LDR R0, = Heap_Mem 347 LDR R1, =(Stack_Mem + Stack_Size) 348 LDR R2, = (Heap_Mem + Heap_Size) 349 LDR R3, = Stack_Mem 350 BX LR 351 352 ALIGN 353 354 ENDIF 355 356 END 357 358 ;******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE*****
要操作STM32寄存器，我们就需要使用C 语言对其封装，这部分程序代码都放在 stm32f10x.h