syscall.c

ucLinux is a very good embeded sytem. Most of company use this as their development OS.

/* vi: set sw=4 ts=4: */
/* syscall for arm/uClibc
 *
 * Copyright (C) 2002 by Erik Andersen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <features.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/syscall.h>


long syscall(long sysnum, long a, long b, long c, long d, long e, long f)
{
#if !defined(__thumb__)
	register long _r0 asm("r0")=(long)(sysnum);
	register long _r6 asm("r6")=(long)(f);
	register long _r5 asm("r5")=(long)(e);
	register long _r4 asm("r4")=(long)(d);
	register long _r3 asm("r3")=(long)(c);
	register long _r2 asm("r2")=(long)(b);
	register long _r1 asm("r1")=(long)(a);
	asm volatile(
			"swi %1"
			: "=r"(_r0)
			: "i"(__NR_syscall), "r"(_r0), "r"(_r1),
			"r"(_r2), "r"(_r3), "r"(_r4), "r"(_r5),
			"r"(_r6)
			: "memory");
#else
	register long _r7 asm("r7")=(long)(sysnum);
	register long _r5 asm("r5")=(long)(f);
	register long _r4 asm("r4")=(long)(e);
	register long _r3 asm("r3")=(long)(d);
	register long _r2 asm("r2")=(long)(c);
	register long _r1 asm("r1")=(long)(b);
	register long _r0 asm("r0")=(long)(a);
	asm volatile(
			"swi 0"
			: "=r"(_r0)
			: "r"(_r0), "r"(_r1), "r"(_r2), "r"(_r3),
			"r"(_r4), "r"(_r5), "r"(_r7)
			: "memory");
#endif
	if(_r0 >=(unsigned long) -4095) {
		long err = _r0;
		(*__errno_location())=(-err);
		_r0=(unsigned long) -1;
	}
	return (long) _r0;
}