1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2016, Richard Lowe.
14 * Copyright 2020 OmniOS Community Edition (OmniOSce) Association.
15 */
16
17 /*
18 * That of the CRT startup routine which itself may be implemented in C.
19 */
20
21 #include <sys/feature_tests.h>
22 #include <sys/types.h>
23
24 #include <stdlib.h>
25 #include <synch.h>
26 #include <unistd.h>
27
28 #pragma weak _DYNAMIC
29 extern uintptr_t _DYNAMIC;
30
31 #pragma weak environ = _environ
32 char **_environ = NULL;
33 char **___Argv = NULL;
34
35 extern int main(int argc, char **argv, char **envp);
36 extern void _init(void);
37 extern void _fini(void);
38
39 #pragma weak __start_crt_compiler
40 extern int __start_crt_compiler(int argc, char **argv);
41
42 #if defined(__x86)
43 int __longdouble_used = 0;
44 extern void __fpstart(void);
45 #endif
46
47 #if defined(__i386) /* Not amd64 */
48 #pragma weak __fsr_init_value
49 extern long __fsr_init_value;
50 extern void __fsr(uintptr_t);
51 #endif
52
53
54 /*
55 * Defined here for ABI reasons, must match the definition in libc.
56 * If it cannot, a new symbol must be created.
57 */
58 mutex_t __environ_lock = DEFAULTMUTEX;
59
60 void
_start_crt(int argc,char ** argv,void (* exit_handler)(void))61 _start_crt(int argc, char **argv, void (*exit_handler)(void))
62 {
63 int ret = 0;
64
65 /*
66 * On x86, we check whether we're a dynamic executable to see whether
67 * we'll receive an exit_handler.
68 *
69 * On SPARC, we just need to check whether the handler was NULL.
70 */
71 #if defined(__x86)
72 if (&_DYNAMIC != NULL)
73 (void) atexit(exit_handler);
74 #elif defined(__sparc)
75 if (exit_handler != NULL)
76 (void) atexit(exit_handler);
77 #endif
78
79 (void) atexit(_fini);
80
81 _environ = argv + (argc + 1);
82 ___Argv = argv;
83
84 /*
85 * __start_crt_compiler() provides a hook for compilers to perform
86 * extra initialisation before main() is called. For example, gcc uses
87 * this to initialise profiling code for objects built with its -pg
88 * option by linking in an extra object that provides this function.
89 *
90 * This mechanism replaces the earlier separate gcrt1.o.
91 *
92 * If __start_crt_compiler() returns a non-zero value, then the
93 * process will exit with that value, without main() being called.
94 */
95 if (&__start_crt_compiler != NULL)
96 ret = __start_crt_compiler(argc, argv);
97
98 if (ret == 0) {
99 #if defined(__x86)
100 __fpstart();
101 #endif
102 #if defined(__i386) /* Not amd64 */
103 /*
104 * Note that Studio cc(1) sets the _value of the symbol_, that
105 * is, its address. Not the value _at_ that address.
106 */
107 __fsr((uintptr_t)&__fsr_init_value);
108 #endif
109 _init();
110 ret = main(argc, argv, _environ);
111 }
112 exit(ret);
113 _exit(ret);
114 }
115