Mon Jul 1 12:29:50 1996 Roland McGrath <roland@delasyd.gnu.ai.mit.edu>

[glibc.git] / sysdeps / unix / sysv / linux / init-first.c

/* Initialization code run first thing by the ELF startup code.  Linux version.
Copyright (C) 1995, 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <unistd.h>
#include <sysdep.h>
#include "fpu_control.h"

/* This code is mostly the same for all machines.  This version works at
   least for i386 and m68k, and probably any CISCy machine with a normal
   stack arrangement.  */

extern void __libc_init (int, char **, char **);
extern void __libc_global_ctors (void);


static void
init (int *data)
{
  extern int __personality (int);

  int argc = *data;
  char **argv = (void *) (data + 1);
  char **envp = &argv[argc + 1];

  /* The `personality' system call takes one argument that chooses the
     "personality", i.e. the set of system calls and such.  Zero is the
     native Linux value; we must make this call first thing to disable
     emulation of some other system that might have been enabled by default
     based on the executable format.  */
  __personality (0);

  /* Set the FPU control word to the proper default value.  */
  __setfpucw (__fpu_control);

  __environ = envp;
  __libc_init (argc, argv, envp);
}

#ifdef PIC
/* This function is called to initialize the shared C library.
   It is called just before the user _start code from i386/elf/start.S,
   with the stack set up as that code gets it.  */

/* NOTE!  The linker notices the magical name `_init' and sets the DT_INIT
   pointer in the dynamic section based solely on that.  It is convention
   for this function to be in the `.init' section, but the symbol name is
   the only thing that really matters!!  */
/*void _init (int argc, ...) __attribute__ ((unused, section (".init")));*/

void
_init (int argc, ...)
{
  init (&argc);

  __libc_global_ctors ();
}
#endif


void
__libc_init_first (int argc __attribute__ ((unused)), ...)
{
#ifndef PIC
  init (&argc);
#endif
}