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/* Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ralf Baechle <ralf@gnu.ai.mit.edu>, 1996.

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

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

        .text
.globl   __clone ;
        .align       2;
        .type         __clone,@function;
        .ent        __clone, 0;
        
__clone:
        .frame      sp, 4*SZREG, sp
#ifdef __PIC__
        .set            noreorder
        .cpload         $25
        .set            reorder
        subu            sp,32
        .cprestore      16
#else
        subu            sp,32
#endif
#ifdef PROF
        .set            noat
        move            $1,ra
        jal             _mcount
        .set            at
#endif


        /* Sanity check arguments.  */
        li              v0,EINVAL
        beqz            a0,error        /* No NULL function pointers.  */
        beqz            a1,error        /* No NULL stack pointers.  */

        subu            a1,32           /* Reserve argument save space.  */
        sw              a0,0(a1)        /* Save function pointer.  */
        sw              a3,4(a1)        /* Save argument pointer.  */


        /* Do the system call */
        move            a0,a2
        li              v0,__NR_clone
        syscall

        bnez            a3,error
        beqz            v0,__thread_start

        /* Successful return from the parent */
        addiu           sp,32
        j $31  ; nop

        /* Something bad happened -- no child created */
error:
        addiu           sp,32
#ifdef __PIC__
        la              t9,__syscall_error
        jr              t9
#else
        j               __syscall_error
#endif
        .end  __clone

/* Load up the arguments to the function.  Put this block of code in
   its own function so that we can terminate the stack trace with our
   debug info.  */

.globl  __thread_start;
        .align 2;
        .ent  __thread_start, 0;

__thread_start:
        /* cp is already loaded.  */
        .cprestore      16
        /* The stackframe has been created on entry of clone().  */
        /* Restore the arg for user's function.  */
        lw              t9,0(sp)        /* Function pointer.  */
        lw              a0,4(sp)        /* Argument pointer.  */

        /* Call the user's function.  */
        jalr            t9

        /* Call _exit rather than doing it inline for breakpoint purposes.  */
        move            a0,v0
#ifdef __PIC__
        la              t9,_exit
        jalr            t9
#else
        jal             _exit
#endif
        .end  __thread_start

.weak clone;
        clone = __clone