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[/] [or1k/] [trunk/] [linux/] [uClibc/] [libc/] [sysdeps/] [linux/] [sh/] [clone.S] - Rev 1765

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/* Copyright (C) 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

/* clone() is even more special than fork() as it mucks with stacks
   and invokes a function in the right context after its all over.  */

#include <features.h>
#include <asm/unistd.h>
#define _ERRNO_H        1
#include <bits/errno.h>


#if defined __HAVE_ELF__ && defined __HAVE_SHARED__ 
#define PLTJMP(_x)      _x##@PLT
#else
#define PLTJMP(_x)      _x
#endif


/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */

        .text

.text
.align 4
.type   __clone,@function
.globl  __clone;
__clone:
        /* sanity check arguments.  */
        tst     r4, r4
        bt      0f
        tst     r5, r5
        bf/s    1f
         mov    #+__NR_clone, r3
0:              
        bra __syscall_error
         mov    #-EINVAL, r4

1:
        /* insert the args onto the new stack */
        mov.l   r7, @-r5
        /* save the function pointer as the 0th element */
        mov.l   r4, @-r5
        
        /* do the system call */
        mov     r6, r4
        trapa   #0x12
        mov     r0, r1
#ifdef __sh2__
// 12 arithmetic shifts for the crappy sh2, because shad doesn't exist! 
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
        shar    r1
#else           
        mov     #-12, r2
        shad    r2, r1
#endif
        not     r1, r1                  // r1=0 means r0 = -1 to -4095
        tst     r1, r1                  // i.e. error in linux
        bf/s    2f
         tst    r0, r0
        bra __syscall_error
         mov    r0, r4

2:
        bt      3f
        rts
         nop
3:
        /* thread starts */
        mov.l   @r15, r1
        jsr     @r1
         mov.l  @(4,r15), r4

        /* we are done, passing the return value through r0  */
        mov.l   .L1, r1
#if defined __HAVE_ELF__ && defined __HAVE_SHARED__ 
        mov.l   r12, @-r15
        sts.l   pr, @-r15
        mov     r0, r4
        mova    .LG, r0  /* .LG from syscall_error.S */
        mov.l   .LG, r12
        add     r0, r12
        mova    .L1, r0
        add     r0, r1
        jsr     @r1
         nop
        lds.l   @r15+, pr
        rts
         mov.l  @r15+, r12
#else
        jmp     @r1
         mov    r0, r4
#endif
        .align  2
.L1:
        .long   PLTJMP(_exit)
.size __clone,.-__clone;

.globl  clone;
    clone = __clone

#include "syscall_error.S"

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