转载地址:https://blog.csdn.net/dear_Wally/article/details/80317934
平台: DA14580 官方 SDK5.4.0
软件:keil5
工程:\5.0.4\projects\target_apps\ble_examples\ble_app_all_in_one\Keil_5
boot_vectors.s 源文件:
;/**************************************************************************//**
; * @file startup_ARMCM0.s
; * @brief CMSIS Core Device Startup File for
; * ARMCM0 Device Series
; * @version V1.08
; * @date 23. November 2012
; *
; * @note
; *
; ******************************************************************************/
;/* Copyright (c) 2011 - 2012 ARM LIMITED
;
; All rights reserved.
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are met:
; - Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
; - Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the distribution.
; - Neither the name of ARM nor the names of its contributors may be used
; to endorse or promote products derived from this software without
; specific prior written permission.
; *
; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
; IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
; ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
; LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
; CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
; SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
; CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
; ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
; POSSIBILITY OF SUCH DAMAGE.
; ---------------------------------------------------------------------------*/
;/*
;//-------- <<< Use Configuration Wizard in Context Menu >>> ------------------
;*/
;// <h> Stack Configuration
;// <o> Stack Size (in Bytes) <0x0-0xFFFFFFFF:8>
;// </h>
Stack_Size EQU 0x00000600
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 0x00000100
AREA HEAP, NOINIT, READWRITE, ALIGN=3
__heap_base
Heap_Mem SPACE Heap_Size
__heap_limit
PRESERVE8
THUMB
;remap uncomment below expression to have the application remap SYSRAM to 0
;__REMAP_SYSRAM EQU 1
; Vector Table Mapped to Address 0 at Reset
; AREA RESET, DATA, READONLY
AREA RESET,DATA, READONLY
EXPORT __Vectors
EXPORT __Vectors_End
EXPORT __Vectors_Size
;ENTRY
__Vectors DCD __initial_sp ; Top of Stack
IF :DEF:__REMAP_SYSRAM
DCD Reset_Handler+0x20000000 ; Reset Handler
ELSE
DCD Reset_Handler ; Reset Handler
ENDIF
DCD NMI_Handler ; NMI Handler
DCD HardFault_Handler ; Hard Fault Handler
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD SVC_Handler ; SVCall Handler
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD PendSV_Handler ; PendSV Handler
DCD SysTick_Handler ; SysTick Handler
DCD BLE_WAKEUP_LP_Handler
DCD BLE_FINETGTIM_Handler
DCD BLE_GROSSTGTIM_Handler
DCD BLE_CSCNT_Handler
DCD BLE_SLP_Handler
DCD BLE_ERROR_Handler
DCD BLE_RX_Handler
DCD BLE_EVENT_Handler
DCD SWTIM_Handler
DCD WKUP_QUADEC_Handler
DCD BLE_RF_DIAG_Handler
DCD BLE_CRYPT_Handler
DCD UART_Handler
DCD UART2_Handler
DCD I2C_Handler
DCD SPI_Handler
DCD ADC_Handler
DCD KEYBRD_Handler
DCD RFCAL_Handler
DCD GPIO0_Handler
DCD GPIO1_Handler
DCD GPIO2_Handler
DCD GPIO3_Handler
DCD GPIO4_Handler
__Vectors_End
__Vectors_Size EQU __Vectors_End - __Vectors
AREA |.text|, CODE, READONLY
; Reset Handler
Reset_Handler PROC
EXPORT Reset_Handler [WEAK]
IMPORT __main
IMPORT SystemInit
;remap
IF :DEF:__REMAP_SYSRAM
LDR R0, =0x0
LDR R1, [R0]
LDR R0, =0x20000000
LDR R2, [R0]
CMP R2, R1
BEQ remap_done
LDR R0, =0x50000012
LDRH R1, [R0]
LSRS R2, R1, #2
LSLS R1, R2, #2
MOVS R2, #0x2
ADDS R1, R1, R2 ;remap SYSRAM to 0
LSLS R2, R2, #14
ADDS R1, R1, R2 ;SW RESET
STRH R1, [R0]
remap_done
ENDIF
;remap
LDR R0, =SystemInit
BLX R0
LDR R0, =__main
BX R0
ENDP
; Dummy Exception Handlers (infinite loops which can be modified)
IMPORT NMI_HandlerC
NMI_Handler\
PROC
movs r0, #4
mov r1, lr
tst r0, r1
beq NMI_stacking_used_MSP
mrs r0, psp
ldr r1,=NMI_HandlerC
bx r1
NMI_stacking_used_MSP
mrs r0, msp
ldr r1,=NMI_HandlerC
bx r1
ENDP
IMPORT HardFault_HandlerC
HardFault_Handler\
PROC
movs r0, #4
mov r1, lr
tst r0, r1
beq HardFault_stacking_used_MSP
mrs r0, psp
ldr r1,=HardFault_HandlerC
bx r1
HardFault_stacking_used_MSP
mrs r0, msp
ldr r1,=HardFault_HandlerC
bx r1
ENDP
IMPORT SVC_Handler_c
SVC_Handler PROC
movs r0, #4
mov r1, lr
tst r0, r1
beq SVC_stacking_used_MSP
mrs r0, psp
ldr r1,=SVC_Handler_c
bx r1
SVC_stacking_used_MSP
mrs r0, msp
ldr r1,=SVC_Handler_c
bx r1
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler [WEAK]
B .
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler [WEAK]
B .
ENDP
Default_Handler PROC
EXPORT BLE_WAKEUP_LP_Handler [WEAK]
EXPORT BLE_FINETGTIM_Handler [WEAK]
EXPORT BLE_GROSSTGTIM_Handler [WEAK]
EXPORT BLE_CSCNT_Handler [WEAK]
EXPORT BLE_SLP_Handler [WEAK]
EXPORT BLE_ERROR_Handler [WEAK]
EXPORT BLE_RX_Handler [WEAK]
EXPORT BLE_EVENT_Handler [WEAK]
EXPORT SWTIM_Handler [WEAK]
EXPORT WKUP_QUADEC_Handler [WEAK]
EXPORT BLE_RF_DIAG_Handler [WEAK]
EXPORT BLE_CRYPT_Handler [WEAK]
EXPORT UART_Handler [WEAK]
EXPORT UART2_Handler [WEAK]
EXPORT I2C_Handler [WEAK]
EXPORT SPI_Handler [WEAK]
EXPORT ADC_Handler [WEAK]
EXPORT KEYBRD_Handler [WEAK]
EXPORT RFCAL_Handler [WEAK]
EXPORT GPIO0_Handler [WEAK]
EXPORT GPIO1_Handler [WEAK]
EXPORT GPIO2_Handler [WEAK]
EXPORT GPIO3_Handler [WEAK]
EXPORT GPIO4_Handler [WEAK]
BLE_WAKEUP_LP_Handler
BLE_FINETGTIM_Handler
BLE_GROSSTGTIM_Handler
BLE_CSCNT_Handler
BLE_SLP_Handler
BLE_ERROR_Handler
BLE_RX_Handler
BLE_EVENT_Handler
SWTIM_Handler
WKUP_QUADEC_Handler
BLE_RF_DIAG_Handler
BLE_CRYPT_Handler
UART_Handler
UART2_Handler
I2C_Handler
SPI_Handler
ADC_Handler
KEYBRD_Handler
RFCAL_Handler
GPIO0_Handler
GPIO1_Handler
GPIO2_Handler
GPIO3_Handler
GPIO4_Handler
B .
ENDP
ALIGN
; User Initial Stack & Heap
IF :DEF:__MICROLIB
EXPORT __initial_sp
EXPORT __heap_base
EXPORT __heap_limit
ELSE
IMPORT __use_two_region_memory
EXPORT __user_initial_stackheap
__user_initial_stackheap
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
下面为转载,针对每条语句的详细讲解:
1 、启动文件简介
DA14580的启动文件为boot_vectors.s,启动文件由汇编编写,是系统上电复位后第一个执行的程序。主要做了以下工作:
1.1、初始化堆栈指针 SP =__initial_sp
1.2、初始化PC指针 =Reset_Handler
1.3、初始化中断向量表
1.4、配置系统时钟
1.5、调用C库函数_main初始化用户堆栈,从而最终调用main函数去到C的世界
3、启动文件代码讲解
3.1、Stack栈配置
Stack_Size EQU 0x00000600
AREA STACK, NOINIT, READWRITE, ALIGN=3
Stack_Mem SPACE Stack_Size
__initial_sp
开辟栈的大小为0X00000600(1.5KB),名字为STACK,NOINIT即不初始化,可读可写,8(2^3)字节对齐。
栈的作用是用于局部变量,函数调用,函数形参等的开销,栈的大小不能超过内部SRAM的大小。如果编写的程序比较大,定义的局部变量很多,那么就需要修改栈的大小。如果某一天,你写的程序出现了莫名奇怪的错误,并进入了硬fault的时候,这时你就要考虑下是不是栈不够大,溢出了。
EQU:宏定义的伪指令,相当于等于,类似与C中的define。
AREA:告诉汇编器汇编一个新的代码段或者数据段。STACK表示段名,这个可以任意命名;NOINIT表示不初始化;READWRITE表示可读可写,ALIGN=3,表示按照2^3对齐,即8字节对齐。
SPACE:用于分配一定大小的内存空间,单位为字节。这里指定大小等于Stack_Size。
标号__initial_sp紧挨着SPACE语句放置,表示栈的结束地址,即栈顶地址,栈是由高向低生长的。
3.2、Heap堆配置
Heap_Size EQU 0x00000100
AREA HEAP, NOINIT, READWRITE, ALIGN=3
__heap_base
Heap_Mem SPACE Heap_Size
__heap_limit
开辟堆的大小为0X00000100(256字节),名字为HEAP,NOINIT即不初始化,可读可写,8(2^3)字节对齐。__heap_base表示堆的起始地址,__heap_limit表示堆的结束地址。堆是由低向高生长的,跟栈的生长方向相反。
堆主要用来动态内存的分配,像malloc()函数申请的内存就在堆上面。
PRESERVE8
THUMB
PRESERVE8:指定当前文件的堆栈按照8字节对齐。
THUMB:表示后面指令兼容THUMB指令。THUBM是ARM以前的指令集,16bit,现在Cortex-M系列的都使用THUMB-2指令集,THUMB-2是32位的,兼容16位和32位的指令,是THUMB的超级。
3.3、向量表
AREA RESET,DATA, READONLY
EXPORT __Vectors
EXPORT __Vectors_End
EXPORT __Vectors_Size
定义一个数据段,名字为RESET,可读。并声明__Vectors、__Vectors_End和__Vectors_Size这三个标号具有全局属性,可供外部的文件调用。
EXPORT:声明一个标号可被外部的文件使用,使标号具有全局属性。如果是IAR编译器,则使用的是GLOBAL这个指令。
当内核响应了一个发生的异常后,对应的异常服务例程(ESR)就会执行。为了决定ESR 的入口地址,内核使用了"向量表查表机制"。这里使用一张向量表。向量表其实是一个WORD(32 位整数)数组,每个下标对应一种异常,该下标元素的值则是该ESR 的入口地址。向量表在地址空间中的位置是可以设置的,通过NVIC 中的一个重定位寄存器来指出向量表的地址。在复位后,该寄存器的值为0。因此,在地址0 (即FLASH 地址0)处必须包含一张向量表,用于初始时的异常分配。要注意的是这里有个另类:0 号类型并不是什么入口地址,而是给出了复位后MSP 的初值。
; Vector Table Mapped to Address 0 at Reset
; AREA RESET, DATA, READONLY
AREA RESET,DATA, READONLY
EXPORT __Vectors
EXPORT __Vectors_End
EXPORT __Vectors_Size
;ENTRY
__Vectors DCD __initial_sp ; Top of Stack
IF :DEF:__REMAP_SYSRAM
DCD Reset_Handler+0x20000000 ; Reset Handler
ELSE
DCD Reset_Handler ; Reset Handler
ENDIF
DCD NMI_Handler ; NMI Handler
DCD HardFault_Handler ; Hard Fault Handler
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD SVC_Handler ; SVCall Handler
DCD 0 ; Reserved
DCD 0 ; Reserved
DCD PendSV_Handler ; PendSV Handler
DCD SysTick_Handler ; SysTick Handler
DCD BLE_WAKEUP_LP_Handler
DCD BLE_FINETGTIM_Handler
DCD BLE_GROSSTGTIM_Handler
DCD BLE_CSCNT_Handler
DCD BLE_SLP_Handler
DCD BLE_ERROR_Handler
DCD BLE_RX_Handler
DCD BLE_EVENT_Handler
DCD SWTIM_Handler
DCD WKUP_QUADEC_Handler
DCD BLE_RF_DIAG_Handler
DCD BLE_CRYPT_Handler
DCD UART_Handler
DCD UART2_Handler
DCD I2C_Handler
DCD SPI_Handler
DCD ADC_Handler
DCD KEYBRD_Handler
DCD RFCAL_Handler
DCD GPIO0_Handler
DCD GPIO1_Handler
DCD GPIO2_Handler
DCD GPIO3_Handler
DCD GPIO4_Handler
__Vectors_End
__Vectors_Size EQU __Vectors_End - __Vectors
__Vectors为向量表起始地址,__Vectors_End 为向量表结束地址,两个相减即可算出向量表大小。
向量表从FLASH的0地址开始放置,以4个字节为一个单位,地址0存放的是栈顶地址,0X04存放的是复位程序的地址,以此类推。从代码上看,向量表中存放的都是中断服务函数的函数名,可我们知道C语言中的函数名就是一个地址。
DCD:分配一个或者多个以字为单位的内存,以四字节对齐,并要求初始化这些内存。在向量表中,DCD分配了一堆内存,并且以ESR的入口地址初始化它们。
3.4、复位程序
AREA |.text|, CODE, READONLY
定义一个名称为.text的代码段,可读。
; Reset Handler
Reset_Handler PROC
EXPORT Reset_Handler [WEAK]
IMPORT __main
IMPORT SystemInit
;remap
IF :DEF:__REMAP_SYSRAM
LDR R0, =0x0
LDR R1, [R0]
LDR R0, =0x20000000
LDR R2, [R0]
CMP R2, R1
BEQ remap_done
LDR R0, =0x50000012
LDRH R1, [R0]
LSRS R2, R1, #2
LSLS R1, R2, #2
MOVS R2, #0x2
ADDS R1, R1, R2 ;remap SYSRAM to 0
LSLS R2, R2, #14
ADDS R1, R1, R2 ;SW RESET
STRH R1, [R0]
remap_done
ENDIF
;remap
LDR R0, =SystemInit
BLX R0
LDR R0, =__main
BX R0
ENDP
复位子程序是系统上电后第一个执行的程序,调用SystemInit函数初始化系统时钟,然后调用C库函数_mian,最终调用main函数去到C的世界。
WEAK:表示弱定义,如果外部文件优先定义了该标号则首先引用该标号,如果外部文件没有声明也不会出错。这里表示复位子程序可以由用户在其他文件重新实现,这里并不是唯一的。
IMPORT:表示该标号来自外部文件,跟C语言中的EXTERN关键字类似。这里表示SystemInit和__main这两个函数均来自外部的文件。
SystemInit()是一个标准的库函数,在system_ARMCM0.c这个文件中定义。主要作用是配置系统时钟。
__main是一个标准的C库函数,主要作用是初始化用户堆栈,最终调用main_func函数去到C的世界。
3.5、中断服务程序
在启动文件里面已经帮我们写好所有中断的中断服务函数,跟我们平时写的中断服务函数不一样的就是这些函数都是空的,真正的中断复服务程序需要我们在外部的C文件里面重新实现,这里只是提前占了一个位置而已。
如果我们在使用某个外设的时候,开启了某个中断,但是又忘记编写配套的中断服务程序或者函数名写错,那当中断来临的时,程序就会跳转到启动文件预先写好的空的中断服务程序中,并且在这个空函数中无限循环,即程序就死在这里。
; Dummy Exception Handlers (infinite loops which can be modified)
IMPORT NMI_HandlerC
NMI_Handler\
PROC
movs r0, #4
mov r1, lr
tst r0, r1
beq NMI_stacking_used_MSP
mrs r0, psp
ldr r1,=NMI_HandlerC
bx r1
NMI_stacking_used_MSP
mrs r0, msp
ldr r1,=NMI_HandlerC
bx r1
ENDP
IMPORT HardFault_HandlerC
HardFault_Handler\
PROC
movs r0, #4
mov r1, lr
tst r0, r1
beq HardFault_stacking_used_MSP
mrs r0, psp
ldr r1,=HardFault_HandlerC
bx r1
HardFault_stacking_used_MSP
mrs r0, msp
ldr r1,=HardFault_HandlerC
bx r1
ENDP
IMPORT SVC_Handler_c
SVC_Handler PROC
movs r0, #4
mov r1, lr
tst r0, r1
beq SVC_stacking_used_MSP
mrs r0, psp
ldr r1,=SVC_Handler_c
bx r1
SVC_stacking_used_MSP
mrs r0, msp
ldr r1,=SVC_Handler_c
bx r1
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler [WEAK]
B .
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler [WEAK]
B .
ENDP
Default_Handler PROC
EXPORT BLE_WAKEUP_LP_Handler [WEAK]
EXPORT BLE_FINETGTIM_Handler [WEAK]
EXPORT BLE_GROSSTGTIM_Handler [WEAK]
EXPORT BLE_CSCNT_Handler [WEAK]
EXPORT BLE_SLP_Handler [WEAK]
EXPORT BLE_ERROR_Handler [WEAK]
EXPORT BLE_RX_Handler [WEAK]
EXPORT BLE_EVENT_Handler [WEAK]
EXPORT SWTIM_Handler [WEAK]
EXPORT WKUP_QUADEC_Handler [WEAK]
EXPORT BLE_RF_DIAG_Handler [WEAK]
EXPORT BLE_CRYPT_Handler [WEAK]
EXPORT UART_Handler [WEAK]
EXPORT UART2_Handler [WEAK]
EXPORT I2C_Handler [WEAK]
EXPORT SPI_Handler [WEAK]
EXPORT ADC_Handler [WEAK]
EXPORT KEYBRD_Handler [WEAK]
EXPORT RFCAL_Handler [WEAK]
EXPORT GPIO0_Handler [WEAK]
EXPORT GPIO1_Handler [WEAK]
EXPORT GPIO2_Handler [WEAK]
EXPORT GPIO3_Handler [WEAK]
EXPORT GPIO4_Handler [WEAK]
BLE_WAKEUP_LP_Handler
BLE_FINETGTIM_Handler
BLE_GROSSTGTIM_Handler
BLE_CSCNT_Handler
BLE_SLP_Handler
BLE_ERROR_Handler
BLE_RX_Handler
BLE_EVENT_Handler
SWTIM_Handler
WKUP_QUADEC_Handler
BLE_RF_DIAG_Handler
BLE_CRYPT_Handler
UART_Handler
UART2_Handler
I2C_Handler
SPI_Handler
ADC_Handler
KEYBRD_Handler
RFCAL_Handler
GPIO0_Handler
GPIO1_Handler
GPIO2_Handler
GPIO3_Handler
GPIO4_Handler
B .
ENDP
3.6、用户堆栈初始化
ALIGN
ALIGN:对指令或者数据存放的地址进行对齐,后面会跟一个立即数。缺省表示4字节对齐。
; User Initial Stack & Heap
IF :DEF:__MICROLIB
EXPORT __initial_sp
EXPORT __heap_base
EXPORT __heap_limit
ELSE
IMPORT __use_two_region_memory
EXPORT __user_initial_stackheap
__user_initial_stackheap
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
判断是否定义了__MICROLIB ,如果定义了则赋予标号__initial_sp(栈顶地址)、__heap_base(堆起始地址)、__heap_limit(堆结束地址)全局属性,可供外部文件调用。如果没有定义(实际的情况就是我们没定义__MICROLIB)则使用默认的C库,然后初始化用户堆栈大小,这部分有C库函数__main来完成,当初始化完堆栈之后,就调用main_func函数去到C的世界。
IF,ELSE,ENDIF:汇编的条件分支语句,跟C语言的if ,else类似
END:文件结束
转自:https://blog.csdn.net/dear_Wally/article/details/80317934