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/* 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; 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
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