C中调用汇编,要把汇编定义为全局的,加.global
C内嵌汇编
__asm__(
:汇编语句部分
:输出部分
:输入部分
:破坏描述部分
);
用C内嵌汇编的方式:实现LED的点亮
//#define GPBCON (volatile unsigned long*)0x56000010
//#define GPBDAT (volatile unsigned long*)0x56000014 #define GPBCON 0x56000010
#define GPBDAT 0x56000014 int gboot_main()
{
//*(GPBCON) = 0x400
//*(GPBDAT) = 0x0; __asm__(
"ldr r1, =0x15400\n"
"str r1,[%0]\n" "ldr r1, =0x6bf\n"
"str r1, [%1]\n"
:
:"r"(GPBCON),"r"(GPBDAT)
:"r1"
);