【经验】实战芯海CS32F031C8T6 MCU使用GCC编译器的startup.s启动文件

芯海推出的32位MCU CS32F031C8T6采用高性能的ARM Cortex®-M0内核，嵌入高达64K Bytes flash和8K Bytes SRAM，最高工作频率48MHz。芯片提供标准的通信接口、ADC，定时器，PWM等丰富的资源。在工业控制、消费类电子等方面有的广泛的应用。

目前CS32F031C8T6官方的Pack包提供的都是基于Keil开发环境的例程，众所周知Keil的费用较高，而GCC是免费的编译器，但一个项目如果移植到GCC的环境工作量最大的主要有以下两个方面：

1、startup.s启动文件的修改，这个部分由于GCC和Keil编译器的汇编格式有所不同，所以需要按照GCC的汇编格式重写startup.s启动文件

2、.ld 文件的编写，.ld文件是GCC编译链接时需要，在此文件中要设置RAM 和ROM 的起始地址和大小，以及堆栈的大小。

本文就以CS32F031C8T6为例，给大家分享一个startup.s文件，希望帮助有需要用GCC开发芯海CS32F031C8T6产品的各位小伙伴。

startup.s启动文件如下：

  .syntax unified

  .cpu cortex-m0

  .fpu softvfp

  .thumb 

.global g_pfnVectors

.global Default_Handler 

.word _sidata

.word _sdata

.word _edata

.word _sbss

.word _ebss 

.equ  BootRAM, 0xF108F85F 

  .section .text.Reset_Handler

  .weak Reset_Handler

  .type Reset_Handler, %function

Reset_Handler:

  ldr   r0, =_estack

  mov   sp, r0

    LDR R0,=0x00000004

    LDR R1, [R0]

    LSRS R1, R1, #24

    LDR R2,=0x1F

    CMP R1, R2

    BNE ApplicationStart

    LDR R0,=0x40021018

    LDR R1,=0x00000001

    STR R1, [R0]

    LDR R0,=0x40010000

    LDR R1,=0x00000000

    STR R1, [R0]

ApplicationStart:

  movs r1, #0

  b LoopCopyDataInit

CopyDataInit:

  ldr r3, =_sidata

  ldr r3, [r3, r1]

  str r3, [r0, r1]

  adds r1, r1, #4

LoopCopyDataInit:

  ldr r0, =_sdata

  ldr r3, =_edata

  adds r2, r0, r1

  cmp r2, r3

  bcc CopyDataInit

  ldr r2, =_sbss

  b LoopFillZerobss

FillZerobss:

  movs r3, #0

  str  r3, [r2]

  adds r2, r2, #4

LoopFillZerobss:

  ldr r3, = _ebss

  cmp r2, r3

  bcc FillZerobss

    bl  SystemInit

  bl main

LoopForever:

    b LoopForever

.size Reset_Handler, .-Reset_Handler

    .section .text.Default_Handler,"ax",%progbits

Default_Handler:

Infinite_Loop:

  b Infinite_Loop

  .size Default_Handler, .-Default_Handler

   .section .isr_vector,"a",%progbits

  .type g_pfnVectors, %object

  .size g_pfnVectors, .-g_pfnVectors

g_pfnVectors:

  .word _estack

  .word Reset_Handler

  .word NMI_Handler

  .word HardFault_Handler

  .word 0

  .word 0

  .word 0

  .word 0

  .word 0

  .word 0

  .word 0

  .word SVC_Handler

  .word 0

  .word 0

  .word PendSV_Handler

  .word SysTick_Handler

  .word WWDT_IRQHandler

  .word PVD_IRQHandler  

  .word RTC_IRQHandler

  .word FLASH_IRQHandler

  .word RCU_IRQHandler

  .word EXTI0_1_IRQHandler

  .word EXTI2_3_IRQHandler

  .word EXTI4_15_IRQHandler

  .word 0  

  .word DMA1_Channel1_IRQHandler

  .word DMA1_Channel2_3_IRQHandler

  .word DMA1_Channel4_5_IRQHandler

  .word ADC1_IRQHandler

  .word TIM1_BRK_UP_TRG_COM_IRQHandler

  .word TIM1_CC_IRQHandler

  .word TIM2_IRQHandler  

  .word TIM3_IRQHandler

  .word 0  

  .word 0  

  .word TIM14_IRQHandler

  .word 0

  .word TIM16_IRQHandler

  .word TIM17_IRQHandler

  .word I2C1_IRQHandler

  .word 0  

  .word SPI1_IRQHandler

  .word 0

  .word USART1_IRQHandler

  .word 0

  .word 0

  .word 0

  .word 0

  .word BootRAM        

  .weak NMI_Handler

  .thumb_set NMI_Handler,Default_Handler

  .weak HardFault_Handler

  .thumb_set HardFault_Handler,Default_Handler

  .weak SVC_Handler

  .thumb_set SVC_Handler,Default_Handler

  .weak PendSV_Handler

  .thumb_set PendSV_Handler,Default_Handler

  .weak SysTick_Handler

  .thumb_set SysTick_Handler,Default_Handler

  .weak WWDT_IRQHandler

  .thumb_set WWDT_IRQHandler,Default_Handler

  .weak PVD_IRQHandler

  .thumb_set PVD_IRQHandler,Default_Handler

  .weak RTC_IRQHandler

  .thumb_set RTC_IRQHandler,Default_Handler

  .weak FLASH_IRQHandler

  .thumb_set FLASH_IRQHandler,Default_Handler

  .weak RCU_IRQHandler

  .thumb_set RCU_IRQHandler,Default_Handler

  .weak EXTI0_1_IRQHandler

  .thumb_set EXTI0_1_IRQHandler,Default_Handler

  .weak EXTI2_3_IRQHandler

  .thumb_set EXTI2_3_IRQHandler,Default_Handler

  .weak EXTI4_15_IRQHandler

  .thumb_set EXTI4_15_IRQHandler,Default_Handler

  .weak DMA1_Channel1_IRQHandler

  .thumb_set DMA1_Channel1_IRQHandler,Default_Handler

  .weak DMA1_Channel2_3_IRQHandler

  .thumb_set DMA1_Channel2_3_IRQHandler,Default_Handler

  .weak DMA1_Channel4_5_IRQHandler

  .thumb_set DMA1_Channel4_5_IRQHandler,Default_Handler

  .weak ADC1_IRQHandler

  .thumb_set ADC1_IRQHandler,Default_Handler

  .weak TIM1_BRK_UP_TRG_COM_IRQHandler

  .thumb_set TIM1_BRK_UP_TRG_COM_IRQHandler,Default_Handler

  .weak TIM1_CC_IRQHandler

  .thumb_set TIM1_CC_IRQHandler,Default_Handler

  .weak TIM2_IRQHandler

  .thumb_set TIM2_IRQHandler,Default_Handler

  .weak TIM3_IRQHandler

  .thumb_set TIM3_IRQHandler,Default_Handler

  .weak TIM14_IRQHandler

  .thumb_set TIM14_IRQHandler,Default_Handler

  .weak TIM16_IRQHandler

  .thumb_set TIM16_IRQHandler,Default_Handler

  .weak TIM17_IRQHandler

  .thumb_set TIM17_IRQHandler,Default_Handler

  .weak I2C1_IRQHandler

  .thumb_set I2C1_IRQHandler,Default_Handler

  .weak SPI1_IRQHandler

  .thumb_set SPI1_IRQHandler,Default_Handler

  .weak USART1_IRQHandler

  .thumb_set USART1_IRQHandler,Default_Handler