sysdeps/mach/start.c

   1 /* Copyright (C) 1992, 1993, 1994, 1995 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, 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 volatile int errno;
  33
  34 extern void __mach_init (void);
  35 extern void __libc_init (int argc, char **argv, char **envp);
  36 extern int main (int argc, char **argv, char **envp);
  37
  38 /* These are uninitialized common definitions so they will be zero
  39    by default.  If the user links in C threads, that will provide initialized
  40    definitions that override these.  */
  41 void *(*_cthread_init_routine) (void); /* Returns new SP to use.  */
  42 void (*_cthread_exit_routine) (int status);
  43
  44
  45 /* These are for communication from _start to start1,
  46    where we cannot use the stack for anything.  */
  47 static int start_argc;
  48 static char **start_argv;
  49
  50 /* _start calls this on the new stack.  */
  51 static volatile void
  52 start1 (void)
  53 {
  54   __libc_init (start_argc, start_argv, __environ);
  55
  56   (_cthread_exit_routine != NULL ? *_cthread_exit_routine : exit)
  57     (main (start_argc, start_argv, __environ));
  58
  59   /* Should never get here.  */
  60   LOSE;
  61 }
  62
  63 #ifndef START_ARGS
  64 #define START_ARGS void
  65 #ifdef START_MACHDEP
  66 START_MACHDEP
  67 #define _start _start0
  68 #endif
  69
  70 void
  71 _start (START_ARGS)
  72 {
  73   SNARF_ARGS (start_argc, start_argv, __environ);
  74
  75   __mach_init ();
  76
  77   if (_cthread_init_routine != NULL)
  78     CALL_WITH_SP (start1, (*_cthread_init_routine) ());
  79   else
  80     start1 ();
  81
  82   /* Should never get here.  */
  83   LOSE;
  84 }