sysdeps/mach/start.c

   1 /* Copyright (C) 1992, 1993, 1994, 1995, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <stddef.h>
  20 #include <stdlib.h>
  21 #include <errno.h>
  22 #include <unistd.h>
  23 #include <sysdep.h>
  24
  25 #ifndef __GNUC__
  26   #error This file uses GNU C extensions; you must compile with GCC.
  27 #endif
  28
  29 /* The first piece of initialized data.  */
  30 int __data_start = 0;
  31
  32 #ifndef _HURD_THREADVAR_H
  33 volatile int errno;
  34 #endif
  35
  36 extern void __mach_init (void);
  37 extern void __libc_init (int argc, char **argv, char **envp);
  38 extern int main (int argc, char **argv, char **envp);
  39
  40 /* These are uninitialized common definitions so they will be zero
  41    by default.  If the user links in C threads, that will provide initialized
  42    definitions that override these.  */
  43 void *(*_cthread_init_routine) (void); /* Returns new SP to use.  */
  44 void (*_cthread_exit_routine) (int status);
  45
  46
  47 /* These are for communication from _start to start1,
  48    where we cannot use the stack for anything.  */
  49 static int start_argc;
  50 static char **start_argv;
  51
  52 /* _start calls this on the new stack.  */
  53 static volatile void
  54 start1 (void)
  55 {
  56   __libc_init (start_argc, start_argv, __environ);
  57
  58   (_cthread_exit_routine != NULL ? *_cthread_exit_routine : exit)
  59     (main (start_argc, start_argv, __environ));
  60
  61   /* Should never get here.  */
  62   LOSE;
  63 }
  64
  65 #ifndef START_ARGS
  66 #define START_ARGS void
  67 #endif
  68 #ifdef START_MACHDEP
  69 START_MACHDEP
  70 #define _start _start0
  71 #endif
  72
  73 void
  74 _start (START_ARGS)
  75 {
  76   SNARF_ARGS (start_argc, start_argv, __environ);
  77
  78   __mach_init ();
  79
  80   if (_cthread_init_routine != NULL)
  81     CALL_WITH_SP (start1, (*_cthread_init_routine) ());
  82   else
  83     start1 ();
  84
  85   /* Should never get here.  */
  86   LOSE;
  87 }