xref: /netbsd-src/lib/csu/common/crt0-common.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
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 #include <sys/syscall.h>
43 #include <machine/profile.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46 
47 #include "rtld.h"
48 
49 extern int main(int, char **, char **);
50 
51 extern void	_init(void);
52 extern void	_fini(void);
53 
54 /*
55  * Arrange for _DYNAMIC to be weak and undefined (and therefore to show up
56  * as being at address zero, unless something else defines it).  That way,
57  * if we happen to be compiling without -static but with without any
58  * shared libs present, things will still work.
59  */
60 extern int _DYNAMIC __weak_reference(_DYNAMIC);
61 
62 #ifdef MCRT0
63 extern void	monstartup(u_long, u_long);
64 extern void	_mcleanup(void);
65 extern unsigned char __etext, __eprol;
66 #endif /* MCRT0 */
67 
68 char		**environ;
69 struct ps_strings *__ps_strings = 0;
70 
71 static char	 empty_string[] = "";
72 char		*__progname = empty_string;
73 
74 void		___start(int, char **, char **, void (*)(void),
75     const Obj_Entry *, struct ps_strings *);
76 
77 #define	write(fd, s, n)	__syscall(SYS_write, (fd), (s), (n))
78 
79 #define	_FATAL(str)				\
80 do {						\
81 	write(2, str, sizeof(str)-1);		\
82 	_exit(1);				\
83 } while (0)
84 
85 void
86 ___start(int argc, char **argv, char **envp,
87     void (*cleanup)(void),			/* from shared loader */
88     const Obj_Entry *obj,			/* from shared loader */
89     struct ps_strings *ps_strings)
90 {
91 	environ = envp;
92 
93 	if (argv[0] != NULL) {
94 		char *c;
95 		__progname = argv[0];
96 		for (c = argv[0]; *c; ++c) {
97 			if (*c == '/')
98 				__progname = c + 1;
99 		}
100 	} else {
101 		__progname = empty_string;
102 	}
103 
104 	if (ps_strings != NULL)
105 		__ps_strings = ps_strings;
106 
107 	if (&_DYNAMIC != NULL) {
108 		if ((obj == NULL) || (obj->magic != RTLD_MAGIC))
109 			_FATAL("Corrupt Obj_Entry pointer in GOT\n");
110 		if (obj->version != RTLD_VERSION)
111 			_FATAL("Dynamic linker version mismatch\n");
112 		atexit(cleanup);
113 	}
114 
115 #ifdef MCRT0
116 	atexit(_mcleanup);
117 	monstartup((u_long)&__eprol, (u_long)&__etext);
118 #endif
119 
120 	atexit(_fini);
121 	_init();
122 
123 	exit(main(argc, argv, environ));
124 }
125