init_handler.c

来自「在s3c2440开发板裸板上模拟软中断处理程序」· C语言 代码 · 共 20 行

unsigned *svi_vec=(unsigned *)0x08; //异常向量0x8
extern void SWI_Handler(void); //中断处理程序

unsigned Install_Handler(unsigned routine,unsigned *vector)
{	/*在异常向量vector地址处写入B指令，相对寻址，
	routine为中断处理程序入口地址*/
	
	unsigned vec,old_vec;
	
	vec=(routine-(unsigned)vector-8)>>2;
	vec=0xea000000 | vec;  //构造B指令
	old_vec=*vector;
	*vector=vec;
	return (old_vec);
}

int init_handler(void)
{
	return Install_Handler((unsigned)SWI_Handler,svi_vec); //构造中断向量
}