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研发客服一个DataAbort异常的触发过程：
///////////////////////////
///xxxx.inc
_STACK_BASEADDRESS EQU 0x33ff8000
_MMUTT_STARTADDRESS EQU 0x33ff8000
_ISR_STARTADDRESS EQU 0x33ffff00
///xxx.s
MACRO
$HandlerLabel HANDLER $HandleLabel
$HandlerLabel
sub sp,sp,#4 ;decrement sp(to store jump address)
stmfd sp!,{r0} ;PUSH the work register to stack(lr does t push because it return to original address)
ldr r0,=$HandleLabel;load the address of HandleXXX to r0
ldr r0,[r0] ;load the contents(service routine start address) of HandleXXX
str r0,[sp,#4] ;store the contents(ISR) of HandleXXX to stack
ldmfd sp!,{r0,pc} ;POP the work register and pc(jump to ISR)
MEND
HandlerPabort HANDLER HandlePabort
HandlerPabort HANDLER HandlePabort 展开:
{
HandlerPabort
sub sp,sp,#4 ;decrement sp(to store jump address)
stmfd sp!,{r0} ;PUSH the work register to stack(lr does''t push because it return to original address)
ldr r0,=$HandlePabort ;load the address of HandleXXX to r0
ldr r0,[r0] ;load the contents(service routine start address) of Handler function
str r0,[sp,#4] ;store the contents(ISR) of HandleXXX to stack
ldmfd sp!,{r0,pc} ;POP the work register and pc(jump to ISR)
}
///xxx.s
/* ^ 其实就是 MAP ，这段程序的意思是，从 _ISR_STARTADDRESS
开始，预留一个变量，每个变量一个标号，预留的空间为 4个字节，也就是 32BIT
，其实这里放的是真正的C写的处理函数的地址，说白了，就是函数指针*/
^ _ISR_STARTADDRESS ; _ISR_STARTADDRESS=0x33FF_FF00
HandleReset # 4
HandleUndef # 4
HandleSWI # 4
HandlePabort # 4
HandleDabort # 4
HandleReserved # 4
HandleIRQ # 4
HandleFIQ # 4
///////////////////////////
xxxx.c
#define _ISR_STARTADDRESS 0x33ffff00
#define pISR_PABORT (*(unsigned *)(_ISR_STARTADDRESS+0xc))
pISR_PABORT=(unsigned)HaltPabort; //给PABORT中断入口函数指针赋值。
【 *PABORTFUNC = HaltPabort 】
/////////////////////
中断触发时：
1 -- ldr r0,=HandlePabort
2 -- (*(unsigned *)HandlePabort） 即是pISR_PABORT
3 -- pISR_PABORT 即是异常处理函数HaltPabort
4 -- POP 出栈时弹出的是HandlePabort 到PC
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