2018年09月05日 | STM8S:Debug调试正常，烧录程序运行不正常

最近有一个项目需要用到STM8S103F3单片机。在开始之前以为会很容易，可是实际操作起来，却遇到不少问题 。其中最令我感到困惑的一个问题是：我在调试程序的时候程序可以运行正常，但当我把程序烧录进去断电重启后却运行不正常。

试了很多方法，都没有找到问题所在。最后，我把Start-up file 选择默认的就可以。之前不知道在哪里看到过可以不使用系统的默认启动文件，可以直接在stm8_interrupt_vector.c中将_stext()改为main()；现在看来真的是害死个让人。

关于STM8S的启动过程：

1）首先bootloader（ROM中）从0x6000地址启动。

2）从bootloader跳转到0x8000（内部FLASH起始地址），0x8000后面才是软件设计可以控制的。很多人不明白的是stm8库里面提供的相关代码，具体流程如下：

a）中断向量表：大家都知道0x8000地址放的是中断函数的地址，而‘0x82’则是stm8内部的中断指令。程序执行到这会自动跳转到中断向量地址所在函数。

b）mian函数到底从哪开始？

这也许是大家最纳闷的了，起始原来很简单：关键是stm8有个复位中断，定义在

stm8_interrupt_vector.c中：

"(void @near (*)())0x8200,"

"_stext, /* RESET */”"

extern void @near _stext(); /* startup routine */

void @near (* const _vectab[])() =

{

"(void @near (*)())0x8200,"

"_stext, /* RESET */"

"(void @near (*)())0x8200,"

"TRAP_IRQHandler, /* TRAP - Software interrupt */"

"(void @near (*)())0x8200,"

"TLI_IRQHandler, /* irq0 - External Top Level interrupt (TLI) */"

"(void @near (*)())0x8200,"

"AWU_IRQHandler, /* irq1 - Auto Wake Up from Halt interrupt */"

"(void @near (*)())0x8200,"

"CLK_IRQHandler, /* irq2 - Clock Controller interrupt */"

"(void @near (*)())0x8200,"

"EXTI_PORTA_IRQHandler, /* irq3 - External interrupt 0 (GPIOA) */"

"(void @near (*)())0x8200,"

"EXTI_PORTB_IRQHandler, /* irq4 - External interrupt 1 (GPIOB) */"

"(void @near (*)())0x8200,"

"EXTI_PORTC_IRQHandler, /* irq5 - External interrupt 2 (GPIOC) */"

"(void @near (*)())0x8200,"

"EXTI_PORTD_IRQHandler, /* irq6 - External interrupt 3 (GPIOD) */"

"(void @near (*)())0x8200,"

"EXTI_PORTE_IRQHandler, /* irq7 - External interrupt 4 (GPIOE) */"

#ifdef STM8S208

"(void @near (*)())0x8200,"

"CAN_RX_IRQHandler, /* irq8 - CAN Rx interrupt */"

"(void @near (*)())0x8200,"

"CAN_TX_IRQHandler, /* irq9 - CAN Tx/ER/SC interrupt */"

#elif defined (STM8S903)

"(void @near (*)())0x8200,"

"EXTI_PORTF_IRQHandler, /* irq8 - External interrupt 5 (GPIOF) */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq9 - Reserved */"

"#else /*STM8S207, STM8S105 or STM8S103*/"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq8 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq9 - Reserved */"

#endif /*STM8S208*/

"(void @near (*)())0x8200,"

"SPI_IRQHandler, /* irq10 - SPI End of transfer interrupt */"

"(void @near (*)())0x8200,"

"TIM1_UPD_OVF_TRG_BRK_IRQHandler, /* irq11 - TIM1 Update/Overflow/Trigger/Break interrupt */"

"(void @near (*)())0x8200,"

"TIM1_CAP_COM_IRQHandler, /* irq12 - TIM1 Capture/Compare interrupt */"

#ifdef STM8S903

"(void @near (*)())0x8200,"

"TIM5_UPD_OVF_BRK_TRG_IRQHandler, /* irq13 - TIM5 Update/Overflow/Break/Trigger interrupt */"

"(void @near (*)())0x8200,"

"TIM5_CAP_COM_IRQHandler, /* irq14 - TIM5 Capture/Compare interrupt */"

"#else /*STM8S208, STM8S207, STM8S105 or STM8S103*/"

"(void @near (*)())0x8200,"

"TIM2_UPD_OVF_BRK_IRQHandler, /* irq13 - TIM2 Update/Overflow/Break interrupt */"

"(void @near (*)())0x8200,"

"TIM2_CAP_COM_IRQHandler, /* irq14 - TIM2 Capture/Compare interrupt */"

#endif /*STM8S903*/

#if defined (STM8S208) || defined(STM8S207) || defined(STM8S105)

"(void @near (*)())0x8200,"

"TIM3_UPD_OVF_BRK_IRQHandler, /* irq15 - TIM3 Update/Overflow/Break interrupt */"

"(void @near (*)())0x8200,"

"TIM3_CAP_COM_IRQHandler, /* irq16 - TIM3 Capture/Compare interrupt */"

#else

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq15 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq16 - Reserved */"

"#endif /*STM8S208, STM8S207 or STM8S105*/"

#ifdef STM8S105

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq17 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq18 - Reserved */"

#else

"(void @near (*)())0x8200,"

"UART1_TX_IRQHandler, /* irq17 - UART1 Tx complete interrupt */"

"(void @near (*)())0x8200,"

"UART1_RX_IRQHandler, /* irq18 - UART1 Rx interrupt */"

#endif /*STM8S105*/

"(void @near (*)())0x8200,"

"I2C_IRQHandler, /* irq19 - I2C interrupt */"

#if defined(STM8S208) || defined(STM8S207)

"(void @near (*)())0x8200,"

"UART3_TX_IRQHandler, /* irq20 - UART3 Tx interrupt */"

"(void @near (*)())0x8200,"

"UART3_RX_IRQHandler, /* irq21 - UART3 Rx interrupt */"

#elif defined (STM8S105)

"(void @near (*)())0x8200,"

"UART2_TX_IRQHandler, /* irq20 - UART2 Tx interrupt */"

"(void @near (*)())0x8200,"

"UART2_RX_IRQHandler, /* irq21 - UART2 Rx interrupt */"

"#else /* STM8S103, STM8S903 */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq20 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq21 - Reserved */"

"#endif /* STM8S208, STM8S207 */"

#if defined(STM8S208) || defined(STM8S207)

"(void @near (*)())0x8200,"

"ADC2_IRQHandler, /* irq22 - ADC2 end of conversion interrupt */"

"#else /* STM8S105, STM8S103, STM8S903 */"

"(void @near (*)())0x8200,"

"ADC1_IRQHandler, /* irq22 - ADC1 end of conversion/Analog watchdog interrupts */"

"#endif /* STM8S208, STM8S207 */"

#ifdef STM8S903

"(void @near (*)())0x8200,"

"TIM6_UPD_OVF_TRG_IRQHandler, /* irq23 - TIM6 Update/Overflow/Trigger interrupt */"

#else

"(void @near (*)())0x8200,"

"TIM4_UPD_OVF_IRQHandler, /* irq23 - TIM4 Update/Overflow interrupt */"

#endif /*STM8S903*/

"(void @near (*)())0x8200,"

"EEPROM_EEC_IRQHandler, /* irq24 - FLASH interrupt */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq25 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq26 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq27 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq28 - Reserved */"

"(void @near (*)())0x8200,"

"NonHandledInterrupt, /* irq29 - Reserved */"

};

复位中断的地址就是0x8000后面的第一个跳转地址，复位后程序自然会跳转到‘_stext’所在地址。‘_stext’在哪里？从‘extern void @near _stext(); /* startup routine */’可以知道它定义在别的文件中，这个文件就是stm8的启动文件，用汇编写的crtsi0.sm8，在cosmic安装目录下可以找到：

; C STARTUP FOR STM8

; WITH AUTOMATIC DATA INITIALISATION

; Copyright (c) 2006 by COSMIC Software

;

"xref _main, __memory, __idesc__, __stack"

"xref.b c_x, c_y, __endzp"

"xdef _exit, __stext"

;

; start address of zpage

;

switch .ubsct

__suzp:

;

; start address of bss

;

switch .bss

__sbss:

;

; startup routine from reset vector

;

switch .text

__stext:

;

; initialize stack pointer

;

"ldw x,#__stack ; stack pointer"

"ldw sp,x ; in place"

;

; setup initialized data

;

"ldw y,__idesc__ ; data start address"

"ldw x,#__idesc__+2 ; descriptor address"

ibcl:

"ld a,(x) ; test flag byte"

jreq zero ; no more segment

"bcp a,#$60 ; test for moveable code segment"

"jreq qbcl ; yes, skip it"

"ldw c_x,x ; save pointer"

"ldw x,(3,x) ; move end address"

"ldw c_y,x ; in memory"

"ldw x,c_x ; reload pointer"

"ldw x,(1,x) ; start address"

dbcl:

"ld a,(y) ; transfer"

"ld (x),a ; byte"

incw x ; increment

incw y ; pointers

"cpw y,c_y ; last byte ?"

"jrne dbcl ; no, loop again"

"ldw x,c_x ; reload pointer"

qbcl:

"addw x,#5 ; next descriptor"

jra ibcl ; and loop

;

; reset uninitialized data in zero page

; 将zero page中未初始化的变量区域清0

zero:

"ldw x,#__suzp ; start of uninitialized zpage ;__suzp为未初始化区域的首地址，也就是.ubsct的起始地址"

jra loop ; test segment end first

zbcl:

"ld (x),a ; clear byte ;清0"

incw x ; next byte;地址加1

loop:

"cpw x,#__endzp ; end of zpage ;__endzp为zeropage内未初始化变量的结束地址，也就是.ubsct的结束地址，"

;_endzp定义在.lkf(链接文件里)，这句的意思是比较现地址是否为.ubsct的结束地址。

"jrne zbcl ; no, continue ;如果.ubsct未初始化完成跳转到abcl继续进行，jrne:不等于则跳转"

;

; reset uninitialized data in bss

"; 将ram中的未初始化变量区域清0,也就是清零.bss段所在区域"

"ldw x,#__sbss ; start address"

jra ok ; test segment end first

bbcl:

"ld (x),a ; clear byte"

incw x ; next byte

ok:

"cpw x,#__memory ; compare end"

"jrne bbcl ; not equal, continue"

; execute main() function

; may be called by a 'jp' instruction if no return expected

;

call _main ; execute main

_exit:

jra _exit ; and stay here

;

end

从启动代码中自然会找到call _main入口。