|
本帖最后由 meiko 于 2017-3-25 18:21 编辑
如题。
IDE是CCS,其中有个boot.c,负责启动后进入main()之前的工作,其中有段关于复位向量的,完全不明白,哪位大神能帮我解释下呀?
文件很短,全部贴出来,其中红色的部分。
那个t 是个啥变量?找不到哪里定义的
#include <stdlib.h>
extern void main_boot(void);
extern void __interrupt _c_int00();
void (*_cleanup_ptr)(void);
void _DATA_ACCESS (*_dtors_ptr)(int);
/*---------------------------------------------------------------------------*/
/* Allocate the memory for the system stack. This section will be sized */
/* by the linker. */
/*---------------------------------------------------------------------------*/
__asm("\t.global __STACK_END");
#pragma DATA_SECTION (_stack, ".stack");
#if defined(__LARGE_DATA_MODEL__)
long _stack;
#else
int _stack;
#endif
/*---------------------------------------------------------------------------*/
/* Initialize reset vector to point at _c_int00 */
/* _c_int00 must always be located in low-memory on MSP430X devices. */
/*---------------------------------------------------------------------------*/
#if defined(__LARGE_CODE_MODEL__)
_Pragma("CODE_SECTION(_c_int00, \".text:_isr\")")
#endif
__asm("\t.global _reset_vector");
__asm("\t.sect \".reset\"");
__asm("\t.align 2");
__asm("_reset_vector:\n\t.field _c_int00, 16");
/*---------------------------------------------------------------------------*/
/* Macro to initialize stack pointer. Stack grows towards lower memory. */
/*---------------------------------------------------------------------------*/
#if defined(__LARGE_DATA_MODEL__)
#define STACK_INIT() __asm("\t MOVX.A\t #__STACK_END,SP")
#else
#define STACK_INIT() __asm("\t MOV.W\t #__STACK_END,SP")
#endif
/*---------------------------------------------------------------------------*/
/* Macros to initialize required global variables. */
/*---------------------------------------------------------------------------*/
#if defined(__TI_EABI__)
#define INIT_EXIT_PTRS() do { } while(0)
#define INIT_LOCKS() do { } while(0)
#else
#define INIT_EXIT_PTRS() do { _cleanup_ptr = NULL; _dtors_ptr = NULL; } while(0)
#define INIT_LOCKS() do { _lock = _nop; _unlock = _nop; } while(0)
#endif
/*****************************************************************************/
/* C_INT00() - C ENVIRONMENT ENTRY POINT */
/*****************************************************************************/
#pragma CLINK(_c_int00)
extern void __interrupt _c_int00()
{
STACK_INIT();
// INIT_EXIT_PTRS();
// INIT_LOCKS();
/*------------------------------------------------------------------------*/
/* Allow for any application-specific low level initialization prior to */
/* initializing the C/C++ environment (global variable initialization, */
/* constructers). If _system_pre_init() returns 0, then bypass C/C++ */
/* initialization. NOTE: BYPASSING THE CALL TO THE C/C++ INITIALIZATION */
/* ROUTINE MAY RESULT IN PROGRAM FAILURE. */
/*------------------------------------------------------------------------*/
// if(_system_pre_init() != 0) _auto_init();
/*------------------------------------------------------------------------*/
/* Handle any argc/argv arguments if supported by an MSP430 loader. */
/*------------------------------------------------------------------------*/
main_boot();
}
|
阿莫论坛20周年了!感谢大家的支持与爱护!!
该献的血还是要献的。你不献他不献。难道让我去献? --- 出自坛友:lovejp1981
|