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Put in proper address information for Poul-Henning Kamp.
[unix-history] / lib / csu.i386 / crt0.c
/*
* Copyright (c) 1993 Paul Kranenburg
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Paul Kranenburg.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software withough specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id: crt0.c,v 1.6 1993/11/09 04:26:11 paul Exp $
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "%W% (Erasmus) %G%";
#endif /* LIBC_SCCS and not lint */
extern void exit();
int _callmain();
#include <sys/param.h>
#ifdef DYNAMIC
#include <sys/types.h>
#include <sys/syscall.h>
#include <a.out.h>
#ifndef N_GETMAGIC
#define N_GETMAGIC(x) ((x).a_magic)
#endif
#ifndef N_BSSADDR
#define N_BSSADDR(x) (N_DATADDR(x)+(x).a_data)
#endif
#include <sys/mman.h>
#ifdef sun
#define MAP_COPY MAP_PRIVATE
#define MAP_FILE 0
#define MAP_ANON 0
#endif
#include <link.h>
extern struct link_dynamic _DYNAMIC;
static void __do_dynamic_link ();
static char *_getenv();
static int _strncmp();
#ifdef sparc
static __call();
#endif
#ifdef sun
#define LDSO "/usr/lib/ld.so"
#endif
#ifdef BSD
#define LDSO "/usr/libexec/ld.so"
#endif
#endif /* DYNAMIC */
static char *_strrchr();
char **environ;
#ifdef BSD
extern unsigned char etext;
extern unsigned char eprol asm ("eprol");
extern start() asm("start");
extern mcount() asm ("mcount");
int errno;
static char empty[1];
char *__progname = empty;
#endif
/*
* We need these system calls, but can't use library stubs
*/
#define _exit(v) __syscall(SYS_exit, (v))
#define open(name, f, m) __syscall(SYS_open, (name), (f), (m))
#define close(fd) __syscall(SYS_close, (fd))
#define read(fd, s, n) __syscall(SYS_read, (fd), (s), (n))
#define write(fd, s, n) __syscall(SYS_write, (fd), (s), (n))
#define dup(fd) __syscall(SYS_dup, (fd))
#define dup2(fd, fdnew) __syscall(SYS_dup2, (fd), (fdnew))
#ifdef sun
#define mmap(addr, len, prot, flags, fd, off) \
__syscall(SYS_mmap, (addr), (len), (prot), _MAP_NEW|(flags), (fd), (off))
#else
#define mmap(addr, len, prot, flags, fd, off) \
__syscall(SYS_mmap, (addr), (len), (prot), (flags), (fd), (off))
#endif
#define _FATAL(str) \
write(2, str, sizeof(str)), \
_exit(1);
#ifdef sparc
asm (" .global start");
asm (" .text");
asm (" start:");
/* Set up `argc', `argv', and `envp' into local registers (from GNU Emacs). */
asm (" mov 0, %fp");
asm (" ld [%sp + 64], %l0"); /* argc */
asm (" add %sp, 68, %l1"); /* argv */
asm (" sll %l0, 2, %l2"); /**/
asm (" add %l2, 4, %l2"); /* envp = argv + (argc << 2) + 4 */
asm (" add %l1, %l2, %l2"); /**/
asm (" sethi %hi(_environ), %l3");
asm (" st %l2, [%l3+%lo(_environ)]"); /* *environ = l2 */
/* Finish diddling with stack. */
asm (" andn %sp, 7, %sp");
asm (" sub %sp, 24, %sp");
#ifdef DYNAMIC
/* Resolve symbols in dynamic libraries */
asm (" call ___do_dynamic_link");
asm (" nop");
#endif
/* From here, all symbols should have been resolved, so we can use libc */
#ifdef MCRT0
asm (" call ___do_mcrt");
asm (" nop");
#endif
/* Stay Sun compatible (currently (SunOS 4.1.2) does nothing on sun4) */
asm (" call start_float");
asm (" nop");
/* Move `argc', `argv', and `envp' from locals to parameters for `main'. */
asm (" mov %l0,%o0");
asm (" mov %l1,%o1");
asm ("__callmain:"); /* Defined for the benefit of debuggers */
asm (" call _main");
asm (" mov %l2,%o2");
asm (" call _exit");
asm (" nop");
#ifdef MCRT0
static void
__do_mcrt ()
{
extern unsigned char eprol, etext;
extern void _mcleanup();
on_exit(_mcleanup, 0);
monstartup(&eprol, &etext);
return;
}
#endif
#endif /* sparc */
#ifdef i386
start()
{
struct kframe {
int kargc;
char *kargv[1]; /* size depends on kargc */
char kargstr[1]; /* size varies */
char kenvstr[1]; /* size varies */
};
/*
* ALL REGISTER VARIABLES!!!
*/
register struct kframe *kfp;
register char **targv;
register char **argv;
extern void _mcleanup();
#ifdef DYNAMIC
volatile caddr_t x;
#endif
#ifdef lint
kfp = 0;
initcode = initcode = 0;
#else /* not lint */
/* just above the saved frame pointer */
asm ("lea 4(%%ebp), %0" : "=r" (kfp) );
#endif /* not lint */
for (argv = targv = &kfp->kargv[0]; *targv++; /* void */)
/* void */ ;
if (targv >= (char **)(*argv))
--targv;
environ = targv;
#ifdef DYNAMIC
/* ld(1) convention: if DYNAMIC = 0 then statically linked */
#ifdef stupid_gcc
if (&_DYNAMIC)
__do_dynamic_link();
#else
x = (caddr_t)&_DYNAMIC;
if (x)
__do_dynamic_link();
#endif
#endif /* DYNAMIC */
asm("eprol:");
#ifdef MCRT0
atexit(_mcleanup);
monstartup(&eprol, &etext);
#endif MCRT0
#if 0
errno = 0;
#endif
if (argv[0])
if ((__progname = _strrchr(argv[0], '/')) == NULL)
__progname = argv[0];
else
++__progname;
asm ("__callmain:"); /* Defined for the benefit of debuggers */
exit(main(kfp->kargc, argv, environ));
}
#endif /* i386 */
#ifdef DYNAMIC
static void
__do_dynamic_link ()
{
struct crt_ldso crt;
struct exec hdr;
char *ldso;
int dupzfd;
void (*entry)();
#ifdef DEBUG
/* Provision for alternate ld.so - security risk! */
if (!(ldso = _getenv("LDSO")))
#endif
ldso = LDSO;
crt.crt_ldfd = open(ldso, 0, 0);
if (crt.crt_ldfd == -1) {
_FATAL("No ld.so\n");
}
/* Read LDSO exec header */
if (read(crt.crt_ldfd, &hdr, sizeof hdr) < sizeof hdr) {
_FATAL("Failure reading ld.so\n");
}
if ((N_GETMAGIC_NET(hdr) != ZMAGIC) && (N_GETMAGIC(hdr) != QMAGIC)) {
_FATAL("Bad magic: ld.so\n");
}
#ifdef sun
/* Get bucket of zeroes */
crt.crt_dzfd = open("/dev/zero", 0, 0);
if (crt.crt_dzfd == -1) {
_FATAL("No /dev/zero\n");
}
#endif
#ifdef BSD
/* We use MAP_ANON */
crt.crt_dzfd = -1;
#endif
#if defined(sun) && defined(DUPZFD)
if ((dupzfd = dup(crt.crt_dzfd)) < 0) {
_FATAL("Cannot dup /dev/zero\n");
}
#endif
/* Map in ld.so */
crt.crt_ba = mmap(0, hdr.a_text,
PROT_READ|PROT_EXEC,
MAP_FILE|MAP_COPY,
crt.crt_ldfd, N_TXTOFF(hdr));
if (crt.crt_ba == -1) {
_FATAL("Cannot map ld.so\n");
}
#ifdef BSD
/* !!!
* This is gross, ld.so is a ZMAGIC a.out, but has `sizeof(hdr)' for
* an entry point and not at PAGSIZ as the N_*ADDR macros assume.
*/
#undef N_DATADDR
#undef N_BSSADDR
#define N_DATADDR(x) ((x).a_text)
#define N_BSSADDR(x) ((x).a_text + (x).a_data)
#endif
/* Map in data segment of ld.so writable */
if (mmap(crt.crt_ba+N_DATADDR(hdr), hdr.a_data,
PROT_READ|PROT_WRITE,
MAP_FIXED|MAP_FILE|MAP_COPY,
crt.crt_ldfd, N_DATOFF(hdr)) == -1) {
_FATAL("Cannot map ld.so\n");
}
/* Map bss segment of ld.so zero */
if (hdr.a_bss && mmap(crt.crt_ba+N_BSSADDR(hdr), hdr.a_bss,
PROT_READ|PROT_WRITE,
MAP_FIXED|MAP_ANON|MAP_COPY,
crt.crt_dzfd, 0) == -1) {
_FATAL("Cannot map ld.so\n");
}
crt.crt_dp = &_DYNAMIC;
crt.crt_ep = environ;
crt.crt_bp = (caddr_t)_callmain;
#if defined(sparc) && defined(SUN_COMPAT)
/* Call Sun's ld.so entry point: version 1, offset crt */
__call(CRT_VERSION_SUN, &crt, crt.crt_ba + sizeof hdr);
#else
entry = (void (*)())(crt.crt_ba + sizeof hdr);
#ifdef SUN_COMPAT
(*entry)(CRT_VERSION_SUN, &crt);
#else
(*entry)(CRT_VERSION_BSD, &crt);
#endif
#endif
#if defined(sun) && defined(DUPZFD)
if (dup2(dupzfd, crt.crt_dzfd) < 0) {
_FATAL("Cannot dup2 /dev/zero\n");
}
(void)close(dupzfd);
#endif
return;
}
#ifdef sparc
static
__call()
{
/*
* adjust the C generated pointer to the crt struct to the
* likings of ld.so, which is an offset relative to its %fp
*/
#if 0
asm("___call:");
asm("call %o2");
asm("sub %o1, %sp, %o1"); /* adjust parameter */
#else Hmmm...
asm("mov %i0, %o0");
asm("mov %i1, %o1");
asm("call %i2");
asm("sub %o1, %sp, %o1");
/*NOTREACHED, control is transferred directly to our caller */
#endif
}
#endif
/*
* Support routines
*/
static int
_strncmp(s1, s2, n)
register char *s1, *s2;
register n;
{
if (n == 0)
return (0);
do {
if (*s1 != *s2++)
return (*(unsigned char *)s1 - *(unsigned char *)--s2);
if (*s1++ == 0)
break;
} while (--n != 0);
return (0);
}
static char *
_getenv(name)
register char *name;
{
extern char **environ;
register int len;
register char **P, *C;
for (C = name, len = 0; *C && *C != '='; ++C, ++len);
for (P = environ; *P; ++P)
if (!_strncmp(*P, name, len))
if (*(C = *P + len) == '=') {
return(++C);
}
return (char *)0;
}
#ifdef sparc
/* System call entry */
asm("___syscall:");
asm("clr %g1");
asm("ta %g0");
asm("bgeu Lsyscallx"); /* good result ? */
asm("nop");
asm("mov -0x1, %o0"); /* Note: no `errno' */
asm("Lsyscallx:");
asm("jmp %o7 + 0x8");
asm("nop");
#endif /* sparc */
#ifdef i386
asm(" ___syscall:");
asm(" popl %ecx");
asm(" popl %eax");
asm(" pushl %ecx");
asm(" .byte 0x9a");
asm(" .long 0");
asm(" .word 7");
asm(" pushl %ecx");
asm(" jc 1f");
asm(" ret");
asm(" 1:");
asm(" movl $-1,%eax");
asm(" ret");
#endif /* i386 */
#endif /* DYNAMIC */
static char *
_strrchr(p, ch)
register char *p, ch;
{
register char *save;
for (save = NULL;; ++p) {
if (*p == ch)
save = (char *)p;
if (!*p)
return(save);
}
/* NOTREACHED */
}
#ifdef MCRT0
asm (" .text");
asm ("_eprol:");
#endif
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.