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/*
* libc/sysdeps/linux/nios2/clone.S -- `clone' syscall for linux/nios2
*
* Copyright (C) 2004 Microtronix Datacom Ltd
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License. See the file COPYING.LIB in the main
* directory of this archive for more details.
*
* Written by Wentao Xu <wentao@microtronix.com>
*/
#define _ERRNO_H
#include <bits/errno.h>
#include <sys/syscall.h>
#ifdef __NR_clone
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
.text
.global clone
.type clone,%function
.align 4
clone:
addi sp,sp,-8
mov r8,r4
stw ra,4(sp)
stw r16,0(sp)
mov r4,r6
movi r2,-EINVAL
/* sanity check */
beq r8,zero,CLONE_ERROR_LABEL
beq r5,zero,CLONE_ERROR_LABEL
/* system call */
movi r2,TRAP_ID_SYSCALL
movi r3,__NR_clone
trap
/* child call the function */
mov r4,r7
bne r2,zero,CLONE_ERROR_LABEL
callr r8
/* exit if it returns */
mov r4,r2
movi r3,__NR_exit
trap
CLONE_ERROR_LABEL:
movi r3,-4096
sub r16,zero,r2
bgeu r3,r2,CLONE_OK
/* store errno */
call __errno_location
stw r16,0(r2)
movi r2,-1
CLONE_OK:
ldw ra,4(sp)
ldw r16,0(sp)
addi sp,sp,8
ret
.size clone,.-clone
#endif
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