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    In addition to the permissions in the GNU Lesser General Public
  10    License, the Free Software Foundation gives you unlimited
  11    permission to link the compiled version of this file with other
  12    programs, and to distribute those programs without any restriction
  13    coming from the use of this file. (The GNU Lesser General Public
  14    License restrictions do apply in other respects; for example, they
  15    cover modification of the file, and distribution when not linked
  16    into another program.)
  17
  18    Note that people who make modified versions of this file are not
  19    obligated to grant this special exception for their modified
  20    versions; it is their choice whether to do so. The GNU Lesser
  21    General Public License gives permission to release a modified
  22    version without this exception; this exception also makes it
  23    possible to release a modified version which carries forward this
  24    exception.
  25
  26    The GNU C Library is distributed in the hope that it will be useful,
  27    but WITHOUT ANY WARRANTY; without even the implied warranty of
  28    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  29    Lesser General Public License for more details.
  30
  31    You should have received a copy of the GNU Lesser General Public
  32    License along with the GNU C Library; if not, write to the Free
  33    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  34    02111-1307 USA.  */
  35
  36 #include <stddef.h>
  37 #include <stdlib.h>
  38 #include <errno.h>
  39 #include <unistd.h>
  40 #include <sysdep.h>
  41
  42 #ifndef __GNUC__
  43   #error This file uses GNU C extensions; you must compile with GCC.
  44 #endif
  45
  46 /* The first piece of initialized data.  */
  47 int __data_start = 0;
  48
  49 #ifndef _HURD_THREADVAR_H
  50 volatile int errno;
  51 #endif
  52
  53 extern void __mach_init (void);
  54 extern void __libc_init (int argc, char **argv, char **envp);
  55 extern int main (int argc, char **argv, char **envp);
  56
  57 /* These are uninitialized common definitions so they will be zero
  58    by default.  If the user links in C threads, that will provide initialized
  59    definitions that override these.  */
  60 void *(*_cthread_init_routine) (void); /* Returns new SP to use.  */
  61 void (*_cthread_exit_routine) (int status);
  62
  63
  64 /* These are for communication from _start to start1,
  65    where we cannot use the stack for anything.  */
  66 static int start_argc;
  67 static char **start_argv;
  68
  69 /* _start calls this on the new stack.  */
  70 static volatile void
  71 start1 (void)
  72 {
  73   __libc_init (start_argc, start_argv, __environ);
  74
  75   (_cthread_exit_routine != NULL ? *_cthread_exit_routine : exit)
  76     (main (start_argc, start_argv, __environ));
  77
  78   /* Should never get here.  */
  79   LOSE;
  80 }
  81
  82 #ifndef START_ARGS
  83 #define START_ARGS void
  84 #endif
  85 #ifdef START_MACHDEP
  86 START_MACHDEP
  87 #define _start _start0
  88 #endif
  89
  90 void
  91 _start (START_ARGS)
  92 {
  93   SNARF_ARGS (start_argc, start_argv, __environ);
  94
  95   __mach_init ();
  96
  97   if (_cthread_init_routine != NULL)
  98     CALL_WITH_SP (start1, (*_cthread_init_routine) ());
  99   else
 100     start1 ();
 101
 102   /* Should never get here.  */
 103   LOSE;
 104 }