启动代码是一段和硬件相关的汇编代码,是必不可少的!这代码主要作用如下:
- 堆栈(SP)的初始化
- 初始化程序计数器(PC)
- 设置向量表异常事件的入口地址
- 调用 main 函数
1、.s启动文件
ST提供的3个启动文件,分别适用于不同容量的STM32芯片。
这三个文件为:
startup_stm32f10x_ld.s
startup_stm32f10x_md.s
startup_stm32f10x_hd.s
其中,ld.s适用于小容量 产品;md.s适用于中等容量产品;hd适用于大容量产品;
这里的容量是指FLASH的大小.判断方法如下:
小容量:FLASH≤32K
中容量:64K≤FLASH≤128K
大容量:256K≤FLASH
.s文件注释:
;******************** (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
; <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>
;
//1、堆栈初始化----------------------------------------------------------/
//堆栈大小设置,如果局部变量过多,这里应该相应改大.默认是1024字节.
Stack_Size EQU 0x00000800 // Stack_Size EQU 定义栈的大小
//AREA伪操作,定义一个段,该段从此开始,到下一个AREA结束。
//栈段,未初始化,允许读写,8字节对齐
AREA STACK, NOINIT, READWRITE, ALIGN=3
//SPACE 伪指令用于分配一片连续的存储区并初始化为0
Stack_Mem SPACE Stack_Size
__initial_sp //代表堆栈顶部地址,也是栈的结束地址
//注意:
// (1) 系统自动分配释放:栈的地址都有专门的寄存器提供存放,也有专门的指令实现进栈、出栈操作,这就决定了栈的效率比较高。
// (2) 所分配的内存是连续的,由高到低分配。栈的最大容量是系统预先规定好的
// (3) 有函数就有栈:断点地址(返回地址)、函数参数、函数内部动态局部变量、函数返回的数据。
; <h> Heap Configuration
; <o> Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>
;未用到编译器自带的内存管理(malloc,free等),设置Heap_Szie为0
Heap_Size EQU 0x00000000 //定义堆的大小
//堆段,未初始化,允许读写,8字节边对齐
AREA HEAP, NOINIT, READWRITE, ALIGN=3
__heap_base //堆的开始地址
Heap_Mem SPACE Heap_Size
__heap_limit //堆的结束地址
PRESERVE8 //伪操作, 用于指定当前文件保存数据至堆栈按八字节对齐
THUMB //表示后面的指令兼容THUMB指令集
//注意:
// (1) 由程序员malloc分配,free释放:效率没有栈高。如果程序员没有free,则分配的内存一直存在直到程序结束后被os回收
// (2) 所提供的内存不连续,从低地址向高地址分配,需要用链表串起来。堆的大小受限于系统中有效的虚拟内存。
// (3) 堆区存放的数据内容由用户决定:数据、数组、结构体、字符串。
//2、定位中断向量表----------------------------------------------------------/
STM32有三个特殊的寄存器:SP、PC、LR。
;SP:栈顶指针。压栈入栈,指向是随时变化的。
;PC:程序计数器。指向下一条将要执行的指令地址。
;LR:保存函数调用的返回地址。
;芯片在上电的时候,在内部时序逻辑的控制下,将0x0000 0000地址的内容保存到SP栈顶;将0x0000 0004地址的内容保存到PC。
;中断向量表首地址存储在0x0000 0000空间上,所以SP将保存栈顶地址__initial_sp,PC将保存复位处理函数地址Reset_Handler。
;所以芯片上电以后,首先执行的便是Reset_Handler函数
; Vector Table Mapped to Address 0 at Reset
//定义一个名为RESET的数据段,权限为只读。
AREA RESET, DATA, READONLY
EXPORT __Vectors //声明的三个symbol可供外部文件调用
EXPORT __Vectors_End
EXPORT __Vectors_Size
//标号__Vectors,表示中断向量表入口地址。
//向量表
/*********************** 建立中断向量表 begin ****************************/
//以字为单位分配一片连续的字存储单元,并用指定的表达式初始化,分配的字存储单元是以字对齐。
// DCD相当于C语言当中的&,定义地址
__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
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
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
/*********************** 建立中断向量表 end ****************************/
__Vectors_Size EQU __Vectors_End - __Vectors
//定义名为.text的代码段,只读
AREA |.text|, CODE, READONLY
//3、调用Reset Handler----------------------------------------------------------/
; Reset handler
//复位中断服务程序,PROC,ENDP结构表示程序的开始和结束。
Reset_Handler PROC
//EXPORT 声明复位中断向量Reset_Handler为全局属性,这样外部文件就可以调用此复位中断服务。
//[WEAK] 汇编编写的虚函数,在其他文件里可以使用或重定义
EXPORT Reset_Handler [WEAK]
//调用main初始化用户堆栈,引导程序进入__main
IMPORT __main
;寄存器版本代码,因为没有用到SystemInit函数,所以注释掉以下代码为防止报错!
;库函数版本代码,建议加上这里(外部必须实现SystemInit函数),以初始化stm32时钟等。
IMPORT SystemInit //导入SystemInit,SystemInit 是在外部c 文件中定义的函数
LDR R0, =SystemInit //将 函数的地址加载到R0寄存器
BLX R0 //BLX表示跳转到对应地址执行
LDR R0, =__main
BX R0
ENDP
; Dummy Exception Handlers (infinite loops which can be modified)
//接下来有很多中断服务函数。但是这些函数在这里是空的,只是占了个位置。真正的中断服务函数程序需要我们在外部c文件里面重新实现。
//如果我们在使用某个外设的时候开启了某个中断,却忘记写中断服务程序,那么当中断被触发,程序就会跳到这里的启动文件里空的中断并无限循环,程序就死了。
NMI_Handler PROC
EXPORT NMI_Handler [WEAK]
B . //跳转到. 表示无限循环
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
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]
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对指令或者数据存放的地址进行对齐,后面会跟立即数,若缺省则表示4字节对齐。
ALIGN
//用户堆栈初始化
;*******************************************************************************
; User Stack and Heap initialization
;*******************************************************************************
//IF…ELSE…ENDIF结构,判断是否使用DEF:__MICROLIB(此处为不使用)。
IF :DEF:__MICROLIB
//若使用DEF:__MICROLIB,则将__initial_sp,__heap_base,__heap_limit亦即栈顶地址,
//堆始末地址赋予全局属性,使外部程序可以使用。
EXPORT __initial_sp
EXPORT __heap_base
EXPORT __heap_limit
ELSE
//定义全局标号__use_two_region_memory。
IMPORT __use_two_region_memory
//声明全局标号__user_initial_stackheap,这样外程序也可调用此标号。
EXPORT __user_initial_stackheap
__user_initial_stackheap // 标号__user_initial_stackheap,表示用户堆栈初始化程序入口。
//分别保存栈顶指针和栈大小,堆始地址和堆大小至R0,R1,R2,R3寄存器。
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
;******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE*****