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/* crt1.s for Solaris 2, x86

   Copyright (C) 1993, 1998, 2008, 2009, 2011 Free Software Foundation, Inc.

   Written By Fred Fish, Nov 1992

This file is free software; you can redistribute it and/or modify it

under the terms of the GNU General Public License as published by the

Free Software Foundation; either version 3, or (at your option) any

later version.

This file 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

General Public License for more details.

Under Section 7 of GPL version 3, you are granted additional

permissions described in the GCC Runtime Library Exception, version

3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and

a copy of the GCC Runtime Library Exception along with this program;

see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

.  */

/* This file takes control of the process from the kernel, as specified

   in section 3 of the System V Application Binary Interface, Intel386

   Processor Supplement.  It has been constructed from information obtained

   from the ABI, information obtained from single stepping existing

   Solaris executables through their startup code with gdb, and from

   information obtained by single stepping executables on other i386 SVR4

   implementations.  This file is the first thing linked into any

   executable.  */

#ifndef GCRT1

        .ident  "GNU C crt1.s"

#define CLEANUP _cleanup

#else

/* This is a modified crt1.s by J.W.Hawtin  15/8/96,

   to allow program profiling, by calling monstartup on entry and _mcleanup

   on exit.  */

        .ident  "GNU C gcrt1.s"

#define CLEANUP _mcleanup

#endif

        .weak   _cleanup

        .weak   _DYNAMIC

        .text

/* Start creating the initial frame by pushing a NULL value for the return

   address of the initial frame, and mark the end of the stack frame chain

   (the innermost stack frame) with a NULL value, per page 3-32 of the ABI.

   Initialize the first stack frame pointer in %ebp (the contents of which

   are unspecified at process initialization).  */

        .globl  _start

_start:

        pushl   $0x0

        pushl   $0x0

        movl    %esp,%ebp

/* As specified per page 3-32 of the ABI, %edx contains a function

   pointer that should be registered with atexit(), for proper

   shared object termination.  Just push it onto the stack for now

   to preserve it.  We want to register _cleanup() first.  */

        pushl   %edx

/* Check to see if there is an _cleanup() function linked in, and if

   so, register it with atexit() as the last thing to be run by

   atexit().  */

        movl    $CLEANUP,%eax

        testl   %eax,%eax

        je      .L1

        pushl   $CLEANUP

        call    atexit

        addl    $0x4,%esp

.L1:

/* Now check to see if we have an _DYNAMIC table, and if so then

   we need to register the function pointer previously in %edx, but

   now conveniently saved on the stack as the argument to pass to

   atexit().  */

        movl    $_DYNAMIC,%eax

        testl   %eax,%eax

        je      .L2

        call    atexit

.L2:

/* Register _fini() with atexit().  We will take care of calling _init()

   directly.  */

        pushl   $_fini

        call    atexit

#ifdef GCRT1

/* Start profiling.  */

        pushl %ebp

        movl %esp,%ebp

        pushl $_etext

        pushl $_start

        call monstartup

        addl $8,%esp

        popl %ebp

#endif

/* Compute the address of the environment vector on the stack and load

   it into the global variable _environ.  Currently argc is at 8 off

   the frame pointer.  Fetch the argument count into %eax, scale by the

   size of each arg (4 bytes) and compute the address of the environment

   vector which is 16 bytes (the two zero words we pushed, plus argc,

   plus the null word terminating the arg vector) further up the stack,

   off the frame pointer (whew!).  */

        movl    8(%ebp),%eax

        leal    16(%ebp,%eax,4),%edx

        movl    %edx,_environ

/* Push the environment vector pointer, the argument vector pointer,

   and the argument count on to the stack to set up the arguments

   for _init(), _fpstart(), and main().  Note that the environment

   vector pointer and the arg count were previously loaded into

   %edx and %eax respectively.  The only new value we need to compute

   is the argument vector pointer, which is at a fixed address off

   the initial frame pointer.  */

/* Make sure the stack is properly aligned.  */

        andl $0xfffffff0,%esp

        subl $4,%esp

        pushl   %edx

        leal    12(%ebp),%edx

        pushl   %edx

        pushl   %eax

/* Call _init(argc, argv, environ), _fpstart(argc, argv, environ), and

   main(argc, argv, environ).  */

        call    _init

        call    __fpstart

        call    main

/* Pop the argc, argv, and environ arguments off the stack, push the

   value returned from main(), and call exit().  */

        addl    $12,%esp

        pushl   %eax

        call    exit

/* An inline equivalent of _exit, as specified in Figure 3-26 of the ABI.  */

        pushl   $0x0

        movl    $0x1,%eax

        lcall   $7,$0

/* If all else fails, just try a halt!  */

        hlt

        .type   _start,@function

        .size   _start,.-_start

#ifndef GCRT1

/* A dummy profiling support routine for non-profiling executables,

   in case we link in some objects that have been compiled for profiling.  */

        .weak   _mcount

_mcount:

        ret

        .type   _mcount,@function

        .size   _mcount,.-_mcount

#endif