本文主要是介绍STM32 标准库V3.5启动文件startup_stm32f10xxx.s分析,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
layout: post
tags: [STM32]
comments: true
文章目录
- layout: post tags: [STM32] comments: true
- 前言
- 分析startup_stm32f10x_md.s
- 汇编指令
- EQU
- AREA
- SPACE
- DCD
- PROC
- LDR
- 常见的转移指令
- 源码分析
前言
这里以stm32f103
为硬件平台,搭建了stm32f1
系列的标准库,版本是V3.5
,在路径标准库的源码路径下Libraries\CMSIS\CM3\DeviceSupport\ST\STM32F10x\startup
包含了各个编译器或者说IDE
的启动文件:
这些IDE
分别是arm
,gcc_ride7
,iar
,TrueSTUDIO
,不过这不是关注的重点,本文主要分析startup_stm32f10x_md.s
。
分析startup_stm32f10x_md.s
首先看一下arm
文件夹下的文件,具体如下;
-ar--- 2011/3/10 10:52 15766 startup_stm32f10x_cl.s
-ar--- 2011/3/10 10:52 15503 startup_stm32f10x_hd.s
-ar--- 2011/3/10 10:52 15692 startup_stm32f10x_hd_vl.s
-ar--- 2011/3/10 10:52 12376 startup_stm32f10x_ld.s
-ar--- 2011/3/10 10:52 13656 startup_stm32f10x_ld_vl.s
-ar--- 2011/3/10 10:52 12765 startup_stm32f10x_md.s
-ar--- 2011/3/10 10:51 14073 startup_stm32f10x_md_vl.s
-ar--- 2011/3/10 10:51 15955 startup_stm32f10x_xl.s
这里可以看到文件最终加以区分的是xl
,md_vl
,md
等等,这些需要根据芯片具体的容量不同进行选择;
下面看一下startup_stm32f10x_md.s
的汇编代码另外一般用户的代码都是从main()
函数开始的,但是在此之前,则有启动代码初始化化硬件环境,然后跳转到 c runtime lib
的__main
中,进行运行环境的初始化,包括栈,堆等等,最终跳转到用户的main
函数中。这里没有找到c runtime lib
的源码,着实有点遗憾。
在分析源码之前,有必要对部分汇编指令进行简单的了解,这里参考了《Cortex_M3权威指南》
汇编指令
EQU
将一个变量赋值,例如:Stack_Size EQU 0x00000400
|
AREA
用于定义一个代码段或数据段,具体用法如:AREA 段名称 {,参数1} {,参数2}...
SPACE
用于申请一片内存空间但不赋初值,例如:Stack_Mem SPACE 0x00000400
,分配1024字节的内存控制,感觉相当于malloc
,Stack_Mem
应该会该内存空间的首地址;
DCD
用于分配一片连续的字存储单元并用伪指令中指定的表达式初始化
PROC
该伪指令用于定义子程序,位置在子程序的开始处,它和ENDP
分别表示子程序定义的开始和结束两者必须成对出现;
LDR
从存储器中加载字到一个寄存器中,Load Data to Register
常见的转移指令
B Label
跳转到 Label 处对应的地址BX reg
跳转到由寄存器 reg 给出的地址BL Label
跳转到 Label 对应的地址,并且把跳转前的下条指令地址保存到 LRBLX reg
跳转到由寄存器reg
给出的地址,并根据 REG 的 LSB 切换处理器状态,还要把转移前的下条指令地址保存到 LR
LR(Link Register),连接寄存器的英文缩写,在ARM体系结构中LR的特殊用途有两种:
一是用来保存子程序返回地址;
二是当异常发生时,LR中保存的值等于异常发生时PC的值减4(或者减2),因此在各种异常模式下可以根据LR的值返回到异常发生前的相应位置继续执行。
源码分析
下面参考一下startup_stm32f10x_md.s
的源码,进行分析一下。
;******************** (C) COPYRIGHT 2011 STMicroelectronics ********************
;* File Name : startup_stm32f10x_md.s
;* Author : MCD Application Team
;* Version : V3.5.0
;* Date : 11-March-2011
;* Description : STM32F10x Medium 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
;* - 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>
Stack_Size EQU 0x00000400 ;栈空间 1024 Bytes,1K的空间;分配数据段,命名为`STACK`,数据段未初始化,可以读写AREA STACK, NOINIT, READWRITE, ALIGN=3 ;
Stack_Mem SPACE Stack_Size
__initial_sp; <h> Heap Configuration
; <o> Heap Size (in Bytes) <0x0-0xFFFFFFFF:8>
; </h>Heap_Size EQU 0x00000200 ;堆空间的配置,512 字节的空间AREA HEAP, NOINIT, READWRITE, ALIGN=3
__heap_base
Heap_Mem SPACE Heap_Size ;分配堆空间为 512字节
__heap_limitPRESERVE8THUMB; Vector Table Mapped to Address 0 at Reset
;向量表映射到地址0x00000000AREA RESET, DATA, READONLYEXPORT __Vectors ;导出__Vectors符号,用于外部文件的使用EXPORT __Vectors_End ;导出向量表的结束地址EXPORT __Vectors_Size ;导出向量表的大小;使用DCD为__initial_sp以及异常地址分配内存空间,存到向量表中
__Vectors DCD __initial_sp ; Top of StackDCD Reset_Handler ; Reset HandlerDCD NMI_Handler ; NMI HandlerDCD HardFault_Handler ; Hard Fault HandlerDCD MemManage_Handler ; MPU Fault HandlerDCD BusFault_Handler ; Bus Fault HandlerDCD UsageFault_Handler ; Usage Fault HandlerDCD 0 ; ReservedDCD 0 ; ReservedDCD 0 ; ReservedDCD 0 ; ReservedDCD SVC_Handler ; SVCall HandlerDCD DebugMon_Handler ; Debug Monitor HandlerDCD 0 ; ReservedDCD PendSV_Handler ; PendSV HandlerDCD SysTick_Handler ; SysTick Handler; External Interrupts; 外设的中断地址DCD WWDG_IRQHandler ; Window WatchdogDCD PVD_IRQHandler ; PVD through EXTI Line detectDCD TAMPER_IRQHandler ; TamperDCD RTC_IRQHandler ; RTCDCD FLASH_IRQHandler ; FlashDCD RCC_IRQHandler ; RCCDCD EXTI0_IRQHandler ; EXTI Line 0DCD EXTI1_IRQHandler ; EXTI Line 1DCD EXTI2_IRQHandler ; EXTI Line 2DCD EXTI3_IRQHandler ; EXTI Line 3DCD EXTI4_IRQHandler ; EXTI Line 4DCD DMA1_Channel1_IRQHandler ; DMA1 Channel 1DCD DMA1_Channel2_IRQHandler ; DMA1 Channel 2DCD DMA1_Channel3_IRQHandler ; DMA1 Channel 3DCD DMA1_Channel4_IRQHandler ; DMA1 Channel 4DCD DMA1_Channel5_IRQHandler ; DMA1 Channel 5DCD DMA1_Channel6_IRQHandler ; DMA1 Channel 6DCD DMA1_Channel7_IRQHandler ; DMA1 Channel 7DCD ADC1_2_IRQHandler ; ADC1_2DCD USB_HP_CAN1_TX_IRQHandler ; USB High Priority or CAN1 TXDCD USB_LP_CAN1_RX0_IRQHandler ; USB Low Priority or CAN1 RX0DCD CAN1_RX1_IRQHandler ; CAN1 RX1DCD CAN1_SCE_IRQHandler ; CAN1 SCEDCD EXTI9_5_IRQHandler ; EXTI Line 9..5DCD TIM1_BRK_IRQHandler ; TIM1 BreakDCD TIM1_UP_IRQHandler ; TIM1 UpdateDCD TIM1_TRG_COM_IRQHandler ; TIM1 Trigger and CommutationDCD TIM1_CC_IRQHandler ; TIM1 Capture CompareDCD TIM2_IRQHandler ; TIM2DCD TIM3_IRQHandler ; TIM3DCD TIM4_IRQHandler ; TIM4DCD I2C1_EV_IRQHandler ; I2C1 EventDCD I2C1_ER_IRQHandler ; I2C1 ErrorDCD I2C2_EV_IRQHandler ; I2C2 EventDCD I2C2_ER_IRQHandler ; I2C2 ErrorDCD SPI1_IRQHandler ; SPI1DCD SPI2_IRQHandler ; SPI2DCD USART1_IRQHandler ; USART1DCD USART2_IRQHandler ; USART2DCD USART3_IRQHandler ; USART3DCD EXTI15_10_IRQHandler ; EXTI Line 15..10DCD RTCAlarm_IRQHandler ; RTC Alarm through EXTI LineDCD USBWakeUp_IRQHandler ; USB Wakeup from suspend
__Vectors_End__Vectors_Size EQU __Vectors_End - __Vectors ; 计算向量表大小AREA |.text|, CODE, READONLY ; 分配代码段,只读; Reset handler
Reset_Handler PROCEXPORT Reset_Handler [WEAK]IMPORT __mainIMPORT SystemInitLDR R0, =SystemInitBLX R0LDR R0, =__mainBX R0ENDP; Dummy Exception Handlers (infinite loops which can be modified)
; [WEAK]指令会优先使用外部的链接符号,但是没有原型,编译器也不会出现报错
NMI_Handler PROCEXPORT NMI_Handler [WEAK]B .ENDP
HardFault_Handler\PROCEXPORT HardFault_Handler [WEAK]B .ENDP
MemManage_Handler\PROCEXPORT MemManage_Handler [WEAK]B .ENDP
BusFault_Handler\PROCEXPORT BusFault_Handler [WEAK]B .ENDP
UsageFault_Handler\PROCEXPORT UsageFault_Handler [WEAK]B .ENDP
SVC_Handler PROCEXPORT SVC_Handler [WEAK]B .ENDP
DebugMon_Handler\PROCEXPORT DebugMon_Handler [WEAK]B .ENDP
PendSV_Handler PROCEXPORT PendSV_Handler [WEAK]B .ENDP
SysTick_Handler PROCEXPORT SysTick_Handler [WEAK]B .ENDPDefault_Handler PROCEXPORT 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]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_IRQHandlerB .ENDPALIGN;*******************************************************************************
; User Stack and Heap initialization
;*******************************************************************************IF :DEF:__MICROLIB EXPORT __initial_spEXPORT __heap_baseEXPORT __heap_limitELSEIMPORT __use_two_region_memoryEXPORT __user_initial_stackheap__user_initial_stackheapLDR R0, = Heap_MemLDR R1, =(Stack_Mem + Stack_Size)LDR R2, = (Heap_Mem + Heap_Size)LDR R3, = Stack_MemBX LRALIGNENDIFEND;******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE*****
主要做了这几个事情:
- 初始化堆栈内存空间;
- 设置
PC
寄存器的地址指向Reset_Handler
,即上电便运行复位程序; - 设置向量表,中断服务程序入口地址;
- 配置系统时钟,
SystemInit
在main
函数运行前就已经运行了; - 运行外部的函数,
LDR R0, =__main
,将__main
地址装载到R0
寄存器并运行,__main
在C库中,会初始化程序的C运行环境,最终调用用户的main
函数;
这篇关于STM32 标准库V3.5启动文件startup_stm32f10xxx.s分析的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!