glibc/sysdeps/unix/start.c

/* Copyright (C) 1991, 93, 1995-1998, 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.

   In addition to the permissions in the GNU Lesser General Public
   License, the Free Software Foundation gives you unlimited
   permission to link the compiled version of this file with other
   programs, and to distribute those programs without any restriction
   coming from the use of this file. (The GNU Lesser General Public
   License restrictions do apply in other respects; for example, they
   cover modification of the file, and distribution when not linked
   into another program.)

   Note that people who make modified versions of this file are not
   obligated to grant this special exception for their modified
   versions; it is their choice whether to do so. The GNU Lesser
   General Public License gives permission to release a modified
   version without this exception; this exception also makes it
   possible to release a modified version which carries forward this
   exception.

   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>
#include <sysdep.h>		/* In case it wants to define anything.  */

/* The first piece of initialized data.  */
int __data_start = 0;
#ifdef HAVE_WEAK_SYMBOLS
weak_alias (__data_start, data_start)
#endif

#ifdef	DUMMIES
#define	ARG_DUMMIES	DUMMIES,
#define	DECL_DUMMIES	int DUMMIES;
#else
#define	ARG_DUMMIES
#define	DECL_DUMMIES
#endif

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


/* Not a prototype because it gets called strangely.  */
static void start1();

#ifndef	HAVE__start

/* N.B.: It is important that this be the first function.
   This file is the first thing in the text section.  */
void
_start ()
{
  start1 ();
}

#ifndef NO_UNDERSCORES
/* Make an alias called `start' (no leading underscore, so it can't
   conflict with C symbols) for `_start'.  This is the name vendor crt0.o's
   tend to use, and thus the name most linkers expect.  */
asm (".set start, __start");
#endif

#endif

/* ARGSUSED */
static void
start1 (ARG_DUMMIES argc, argp)
     DECL_DUMMIES
     int argc;
     char *argp;
{
  char **argv = &argp;

  /* The environment starts just after ARGV.  */
  __environ = &argv[argc + 1];

  /* If the first thing after ARGV is the arguments
     themselves, there is no environment.  */
  if ((char *) __environ == *argv)
    /* The environment is empty.  Make __environ
       point at ARGV[ARGC], which is NULL.  */
    --__environ;

  /* Do C library initializations.  */
  __libc_init (argc, argv, __environ);

  /* Call the user program.  */
  exit (main (argc, argv, __environ));
}