lib/csu/common/crt0-common.c

   1 /* $NetBSD: crt0-common.c,v 1.1 2010/08/07 18:01:33 joerg Exp $ */
   2
   3 /*
   4  * Copyright (c) 1998 Christos Zoulas
   5  * Copyright (c) 1995 Christopher G. Demetriou
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *          This product includes software developed for the
  19  *          NetBSD Project.  See http://www.NetBSD.org/ for
  20  *          information about NetBSD.
  21  * 4. The name of the author may not be used to endorse or promote products
  22  *    derived from this software without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
  36  */
  37
  38 #include <sys/cdefs.h>
  39 __RCSID("$NetBSD: crt0-common.c,v 1.1 2010/08/07 18:01:33 joerg Exp $");
  40
  41 #include <sys/types.h>
  42 #ifndef __minix
  43 #include <sys/syscall.h>
  44 #endif
  45 #include <machine/profile.h>
  46 #include <stdlib.h>
  47 #include <unistd.h>
  48
  49 #include "rtld.h"
  50
  51 extern int main(int, char **, char **);
  52
  53 extern void     _init(void);
  54 extern void     _fini(void);
  55
  56 /*
  57  * Arrange for _DYNAMIC to be weak and undefined (and therefore to show up
  58  * as being at address zero, unless something else defines it).  That way,
  59  * if we happen to be compiling without -static but with without any
  60  * shared libs present, things will still work.
  61  */
  62
  63 #if __GNUC_PREREQ__(4,2)
  64 static int rtld_DYNAMIC __attribute__((__weakref__, __alias__("_DYNAMIC")));
  65 #define DYNAMIC_SYM     rtld_DYNAMIC
  66 #else
  67 extern int _DYNAMIC __weak_reference(_DYNAMIC);
  68 #define DYNAMIC_SYM     _DYNAMIC
  69 #endif
  70
  71 #ifdef MCRT0
  72 extern void     monstartup(u_long, u_long);
  73 extern void     _mcleanup(void);
  74 extern unsigned char __etext, __eprol;
  75 #endif /* MCRT0 */
  76
  77 char            **environ;
  78 struct ps_strings *__ps_strings = 0;
  79
  80 static char      empty_string[] = "";
  81 char            *__progname = empty_string;
  82
  83 void            ___start(int, char **, char **, void (*)(void),
  84     const Obj_Entry *, struct ps_strings *);
  85
  86 #ifndef __minix
  87 #define write(fd, s, n) __syscall(SYS_write, (fd), (s), (n))
  88 #else
  89 #define write(fd, s, n) /* NO write() from here on minix */
  90 #endif
  91
  92 #define _FATAL(str)                             \
  93 do {                                            \
  94         write(2, str, sizeof(str)-1);           \
  95         _exit(1);                               \
  96 } while (0)
  97
  98 void
  99 ___start(int argc, char **argv, char **envp,
 100     void (*cleanup)(void),                      /* from shared loader */
 101     const Obj_Entry *obj,                       /* from shared loader */
 102     struct ps_strings *ps_strings)
 103 {
 104         environ = envp;
 105
 106         if (argv[0] != NULL) {
 107                 char *c;
 108                 __progname = argv[0];
 109                 for (c = argv[0]; *c; ++c) {
 110                         if (*c == '/')
 111                                 __progname = c + 1;
 112                 }
 113         } else {
 114                 __progname = empty_string;
 115         }
 116
 117         if (ps_strings != NULL)
 118                 __ps_strings = ps_strings;
 119
 120         if (&DYNAMIC_SYM != NULL) {
 121                 if ((obj == NULL) || (obj->magic != RTLD_MAGIC))
 122                         _FATAL("Corrupt Obj_Entry pointer in GOT\n");
 123                 if (obj->version != RTLD_VERSION)
 124                         _FATAL("Dynamic linker version mismatch\n");
 125                 atexit(cleanup);
 126         }
 127
 128 #ifdef MCRT0
 129         atexit(_mcleanup);
 130         monstartup((u_long)&__eprol, (u_long)&__etext);
 131 #endif
 132
 133         atexit(_fini);
 134         _init();
 135
 136         exit(main(argc, argv, environ));
 137 }