#define __NR_SYSCALL_BASE 0x900000
#define __NR_exit1 (__NR_SYSCALL_BASE+ 1)
#define __NR_write (__NR_SYSCALL_BASE+ 4)
#define __sys2(x) #x
#define __sys1(x) __sys2(x)
#ifndef __syscall
#define __syscall(name) "swi\t" __sys1(__NR_##name) "\n\t"
#endif
#define __syscall_return(type, res) \
do { \
return (type) (res); \
} while (0)
#define _syscall0(type,name) \
type name(void) { \
long __res; \
__asm__ __volatile__ ( \
__syscall(name) \
"mov %0,r0" \
:"=r" (__res) : : "r0","lr"); \
__syscall_return(type,__res); \
}
#define _syscall1(type,name,type1,arg1) \
type name(type1 arg1) { \
"mov\tr0,%1\n\t" \
: "=r" (__res) \
: "r" ((long)(arg1)) \
: "r0","lr"); \
#define _syscall2(type,name,type1,arg1,type2,arg2) \
type name(type1 arg1,type2 arg2) { \
"mov\tr1,%2\n\t" \
"mov\t%0,r0" \
: "r" ((long)(arg1)),"r" ((long)(arg2)) \
: "r0","r1","lr"); \
#define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3) \
type name(type1 arg1,type2 arg2,type3 arg3) { \
"mov\tr2,%3\n\t" \
: "r" ((long)(arg1)),"r" ((long)(arg2)),"r" ((long)(arg3)) \
: "r0","r1","r2","lr"); \
#define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4) \
type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
"mov\tr3,%4\n\t" \
: "r" ((long)(arg1)),"r" ((long)(arg2)),"r" ((long)(arg3)),"r" ((long)(arg4)) \
: "r0","r1","r2","r3","lr"); \
#define _syscall5(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4,type5,arg5) \
type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5) { \
"mov\tr4,%5\n\t" \
: "r" ((long)(arg1)),"r" ((long)(arg2)),"r" ((long)(arg3)),"r" ((long)(arg4)), \
"r" ((long)(arg5)) \
: "r0","r1","r2","r3","r4","lr"); \
_syscall1(int,exit1,int,status);
_syscall3(int,write,int,fd,const char *,buf, int, len);
void _start(void)
{
write(1, "Hello World\n", 12);
exit1(0);