glibc/sysdeps/unix/sysv/irix4/start.c

/* Copyright (C) 1991, 1992, 1995, 1996, 1997 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.  */

#include <errno.h>
#include <stdlib.h>
#include <unistd.h>

#ifndef	__GNUC__
  #error This file uses GNU C extensions; you must compile with GCC.
#endif

/* The first piece of initialized data.  */
int __data_start = 0;

extern void __libc_init __P ((int argc, char **argv, char **envp));
extern int main __P ((int argc, char **argv, char **envp));

/* Use the stack pointer to access the arguments.  This assumes that
   we can guess how big the frame will be.  */
register long int sp asm("sp");
#ifdef __OPTIMIZE__
#define STACKSIZE 8
#else
#define STACKSIZE 10
#endif

void
__start ()
{
  int argc;
  char **argv, **envp;

  /* Set up the global pointer.  */
  asm volatile ("la $28,_gp");
  argc = ((int *) sp)[STACKSIZE];
  argv = (char **) &((int *) sp)[STACKSIZE + 1];
  envp = &argv[argc + 1];
  __environ = envp;

  __libc_init (argc, argv, envp);
  errno = 0;
  exit (main (argc, argv, envp));
}