176 lines
4.8 KiB
C
176 lines
4.8 KiB
C
/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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., 675 Mass Ave,
|
||
Cambridge, MA 02139, USA. */
|
||
|
||
#include <ansidecl.h>
|
||
#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;
|
||
|
||
extern void EXFUN(__libc_init, (int argc, char **argv, char **envp));
|
||
extern int EXFUN(main, (int argc, char **argv, char **envp));
|
||
|
||
register long int sp asm("%sp"), fp asm("%fp");
|
||
|
||
#ifndef NO_SHLIB
|
||
static void EXFUN(init_shlib, (NOARGS));
|
||
#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
|
||
DEFUN_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
|