xref: /openbsd/lib/csu/crt0.c (revision 8529ddd3)
1 /*	$OpenBSD: crt0.c,v 1.4 2014/12/27 16:04:22 kettenis Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Christopher G. Demetriou
18  *	for the NetBSD Project.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <stdlib.h>
35 #include <limits.h>
36 
37 #include "md_init.h"
38 #ifdef MD_RCRT0_START
39 #include "boot.h"
40 #endif
41 
42 /* some defaults */
43 #ifndef	MD_START_ARGS
44 #define	MD_START_ARGS	\
45 	int argc, char **argv, char **envp, void (*cleanup)(void)
46 #endif
47 #ifndef MD_START
48 #define	MD_START	___start
49 static void		___start(MD_START_ARGS) __used;
50 #endif
51 #ifndef	MD_EPROL_LABEL
52 #define	MD_EPROL_LABEL	__asm("  .text\n_eprol:")
53 #endif
54 
55 void	__init_tcb(char **_envp);
56 #pragma weak __init_tcb
57 
58 static char	*_strrchr(char *, char);
59 
60 char	**environ;
61 char	*__progname = "";
62 char	__progname_storage[NAME_MAX+1];
63 
64 #ifdef MCRT0
65 extern void	monstartup(u_long, u_long);
66 extern void	_mcleanup(void);
67 extern unsigned char _etext, _eprol;
68 #endif /* MCRT0 */
69 
70 #ifdef RCRT0
71 #ifdef MD_RCRT0_START
72 MD_RCRT0_START;
73 #endif
74 #else
75 #ifdef MD_CRT0_START
76 MD_CRT0_START;
77 #endif
78 #endif
79 
80 void
81 MD_START(MD_START_ARGS)
82 {
83 	char *namep, *s;
84 #ifdef MD_START_SETUP
85 	MD_START_SETUP
86 #endif
87 
88 	environ = envp;
89 
90 	if ((namep = argv[0]) != NULL) {	/* NULL ptr if argc = 0 */
91 		if ((__progname = _strrchr(namep, '/')) == NULL)
92 			__progname = namep;
93 		else
94 			__progname++;
95 		for (s = __progname_storage; *__progname &&
96 		    s < &__progname_storage[sizeof __progname_storage - 1]; )
97 			*s++ = *__progname++;
98 		*s = '\0';
99 		__progname = __progname_storage;
100 	}
101 
102 #ifndef MD_NO_CLEANUP
103 	if (cleanup != NULL)
104 		atexit(cleanup);
105 	else
106 #endif
107 	if (__init_tcb != NULL)
108 		__init_tcb(envp);
109 
110 #ifdef MCRT0
111 	atexit(_mcleanup);
112 	monstartup((u_long)&_eprol, (u_long)&_etext);
113 #endif
114 
115 	__init();
116 
117 	exit(main(argc, argv, envp));
118 }
119 
120 static char *
121 _strrchr(char *p, char ch)
122 {
123 	char *save;
124 
125 	for (save = NULL;; ++p) {
126 		if (*p == ch)
127 			save = p;
128 		if (*p == '\0')
129 			return (save);
130 	}
131 }
132 
133 #ifdef MCRT0
134 MD_EPROL_LABEL;
135 #endif
136