uclibc-ng/ldso/ldso/i386/dl-syscalls.h

#include <linux/types.h>
#include <asm/unistd.h>

/* Here are the macros which define how this platform makes
 * system calls.  This particular variant does _not_ set 
 * errno (note how it is disabled in __syscall_return) since
 * these will get called before the errno symbol is dynamicly 
 * linked.
   by the dynamic linker.  The idea is that we want to be able
   to call these before the errno symbol is dynamicly linked, so
   we use our own version here.  Note that we cannot assume any
   dynamic linking at all, so we cannot return any error codes.
   We just punt if there is an error. */


#undef __syscall_return
#define __syscall_return(type, res) \
do { \
	if ((unsigned long)(res) >= (unsigned long)(-125)) { \
		/*errno = -(res); */ \
		res = -1; \
	} \
	return (type) (res); \
} while (0)


#if defined(__PIC__)

/*
 * PIC uses %ebx, so we need to save it during system calls
 */

#undef _syscall1
#define _syscall1(type,name,type1,arg1) \
type name(type1 arg1) \
{ \
long __res; \
__asm__ volatile ("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
	: "=a" (__res) \
	: "0" (__NR_##name),"r" ((long)(arg1))); \
__syscall_return(type,__res); \
}

#undef _syscall2
#define _syscall2(type,name,type1,arg1,type2,arg2) \
type name(type1 arg1,type2 arg2) \
{ \
long __res; \
__asm__ volatile ("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
	: "=a" (__res) \
	: "0" (__NR_##name),"r" ((long)(arg1)),"c" ((long)(arg2))); \
__syscall_return(type,__res); \
}

#undef _syscall3
#define _syscall3(type,name,type1,arg1,type2,arg2,type3,arg3) \
type name(type1 arg1,type2 arg2,type3 arg3) \
{ \
long __res; \
__asm__ volatile ("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
	: "=a" (__res) \
	: "0" (__NR_##name),"r" ((long)(arg1)),"c" ((long)(arg2)), \
		"d" ((long)(arg3))); \
__syscall_return(type,__res); \
}

#undef _syscall4
#define _syscall4(type,name,type1,arg1,type2,arg2,type3,arg3,type4,arg4) \
type name (type1 arg1, type2 arg2, type3 arg3, type4 arg4) \
{ \
long __res; \
__asm__ volatile ("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
	: "=a" (__res) \
	: "0" (__NR_##name),"r" ((long)(arg1)),"c" ((long)(arg2)), \
	  "d" ((long)(arg3)),"S" ((long)(arg4))); \
__syscall_return(type,__res); \
}

#undef _syscall5
#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) \
{ \
long __res; \
__asm__ volatile ("push %%ebx; movl %2,%%ebx; int $0x80; pop %%ebx" \
	: "=a" (__res) \
	: "0" (__NR_##name),"m" ((long)(arg1)),"c" ((long)(arg2)), \
	  "d" ((long)(arg3)),"S" ((long)(arg4)),"D" ((long)(arg5))); \
__syscall_return(type,__res); \
}

#endif /* __PIC__ */