1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
/* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#ifndef NO_SHLIB
#include <sys/exec.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <link.h>
#include <syscall.h>
#endif
#if !defined (__GNUC__) || __GNUC__ < 2
#error This file uses GNU C extensions; you must compile with GCC version 2.
#endif
/* The first piece of initialized data. */
int __data_start = 0;
#ifdef HAVE_WEAK_SYMBOLS
weak_alias (__data_start, data_start)
#endif
VOLATILE int __errno;
strong_alias (__errno, errno)
extern void __libc_init __P ((int argc, char **argv, char **envp));
extern int main __P ((int argc, char **argv, char **envp));
register long int sp asm("%sp"), fp asm("%fp");
#ifndef NO_SHLIB
static void init_shlib __P ((void));
#endif
#ifndef NO_EXPLICIT_START
/* Declare _start with an explicit assembly symbol name of `start'
(note no leading underscore). This is the name Sun's crt0.o uses,
and programs are often linked with `ld -e start'. */
void _start (void) asm ("start");
#endif
void
_start (void)
{
/* It is important that these be declared `register'.
Otherwise, when compiled without optimization, they are put on the
stack, which loses completely after we zero the FP. */
register int argc;
register char **argv, **envp;
/* Unwind the frame built when we entered the function. */
asm("restore");
/* And clear the frame pointer. */
fp = 0;
/* The argument info starts after one register
window (64 bytes) past the SP. */
argc = ((int *) sp)[16];
argv = (char **) &((int *) sp)[17];
envp = &argv[argc + 1];
__environ = envp;
#ifndef NO_SHLIB
init_shlib ();
#endif
/* Allocate 24 bytes of stack space for the register save area. */
sp -= 24;
__libc_init (argc, argv, envp);
exit (main (argc, argv, envp));
}
#ifndef NO_SHLIB
/* System calls for use by the bootstrap routine.
These are defined here since the usual calls may be dynamically linked. */
int syscall (int sysno, ...) asm ("init_syscall");
asm ("init_syscall:\n"
" clr %g1\n"
" ta 0\n"
" bcc 1f\n"
" sethi %hi(_errno), %g1\n"
" st %o0, [%g1 + %lo(_errno)]\n"
" sub %g0, 1, %o0\n"
"1:retl\n"
" nop");
static void
init_shlib ()
{
extern struct link_dynamic _DYNAMIC;
int so, zf;
caddr_t somap;
caddr_t sodmap;
caddr_t sobssmap;
void (*ldstart) (int, int);
struct exec soexec;
struct
{
caddr_t crt_ba;
int crt_dzfd;
int crt_ldfd;
struct link_dynamic *crt_dp;
char **crt_ep;
caddr_t crt_bp;
} soarg;
/* If not dynamically linked, do nothing. */
if (&_DYNAMIC == 0)
return;
/* Map in the dynamic linker. */
so = syscall (SYS_open, "/usr/lib/ld.so", O_RDONLY);
if (syscall (SYS_read, so, &soexec, sizeof (soexec)) != sizeof (soexec)
|| soexec.a_magic != ZMAGIC)
{
static const char emsg[] = "crt0: no /usr/lib/ld.so\n";
syscall (SYS_write, 2, emsg, sizeof (emsg) - 1);
syscall (SYS_exit, 127);
}
somap = (caddr_t) syscall (SYS_mmap, 0,
soexec.a_text + soexec.a_data + soexec.a_bss,
PROT_READ | PROT_EXEC, _MAP_NEW | MAP_PRIVATE,
so, 0);
sodmap = (caddr_t) syscall (SYS_mmap, somap + soexec.a_text, soexec.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
_MAP_NEW | MAP_FIXED | MAP_PRIVATE,
so, soexec.a_text);
zf = syscall (SYS_open, "/dev/zero", O_RDONLY);
if (soexec.a_bss != 0)
sobssmap = (caddr_t) syscall (SYS_mmap,
somap + soexec.a_text + soexec.a_data,
soexec.a_bss,
PROT_READ | PROT_WRITE | PROT_EXEC,
_MAP_NEW | MAP_FIXED | MAP_PRIVATE,
zf, 0);
/* Call the entry point of the dynamic linker. */
soarg.crt_ba = somap;
soarg.crt_dzfd = zf;
soarg.crt_ldfd = so;
soarg.crt_dp = &_DYNAMIC;
soarg.crt_ep = __environ;
soarg.crt_bp = (caddr_t) &&retaddr;
ldstart = (__typeof (ldstart)) (somap + soexec.a_entry);
(*ldstart) (1, (char *) &soarg - (char *) sp);
retaddr:
}
#endif
|
