sysdeps/unix/sysv/linux/init-first.c

   1 /* Initialization code run first thing by the ELF startup code.  Linux version.
   2 Copyright (C) 1995, 1996 Free Software Foundation, Inc.
   3 This file is part of the GNU C Library.
   4
   5 The GNU C Library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 License, or (at your option) any later version.
   9
  10 The GNU C Library is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #include <unistd.h>
  21 #include <sysdep.h>
  22 #include <fpu_control.h>
  23 #include "init-first.h"
  24
  25 extern void __libc_init (int, char **, char **);
  26 extern void __libc_global_ctors (void);
  27
  28 /* The function is called from assembly stubs the compiler can't see.  */
  29 static void init (void *) __attribute__ ((unused));
  30
  31 static void
  32 init (void *data)
  33 {
  34   extern int __personality (int);
  35
  36   int argc = *(long *)data;
  37   char **argv = (char **)data + 1;
  38   char **envp = &argv[argc + 1];
  39
  40   /* The `personality' system call takes one argument that chooses the
  41      "personality", i.e. the set of system calls and such.  Zero is the
  42      native Linux value; we must make this call first thing to disable
  43      emulation of some other system that might have been enabled by default
  44      based on the executable format.  */
  45   __personality (0);
  46
  47   /* Set the FPU control word to the proper default value.  */
  48   __setfpucw (__fpu_control);
  49
  50   __environ = envp;
  51   __libc_init (argc, argv, envp);
  52
  53 #ifdef PIC
  54   __libc_global_ctors ();
  55 #endif
  56 }
  57
  58 #ifdef PIC
  59
  60 SYSDEP_CALL_INIT(_init, init);
  61
  62 void
  63 __libc_init_first (void)
  64 {
  65 }
  66
  67 #else
  68
  69 SYSDEP_CALL_INIT(__libc_init_first, init);
  70
  71 #endif