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/*
* Mach Operating System
* Copyright (c) 1991,1990,1989 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*/
/*
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement: ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char sccsid[] = "@(#)crt0.c 5.2 (Berkeley) 5/14/90";
#endif /* not lint */
/*
* C start up routine.
* Robert Henry, UCB, 20 Oct 81
*
* We make the following (true) assumptions:
* 1) when the kernel calls start, it does a jump to location 2,
* and thus avoids the register save mask. We are NOT called
* with a calls! see sys1.c:setregs().
* 2) The only register variable that we can trust is sp,
* which points to the base of the kernel calling frame.
* Do NOT believe the documentation in exec(2) regarding the
* values of fp and ap.
* 3) We can allocate as many register variables as we want,
* and don't have to save them for anybody.
* 4) Because of the ways that asm's work, we can't have
* any automatic variables allocated on the stack, because
* we must catch the value of sp before any automatics are
* allocated.
*/
#include <mach/machine/asm.h>
char **environ = (char **)0;
#ifdef paranoid
static int fd;
#endif paranoid
int (*mach_init_routine)();
int (*_cthread_init_routine)();
int (*_cthread_exit_routine)();
int (*_monstartup_routine)();
int (*_StrongBox_init_routine)();
int errno = 0;
int exit();
extern int main();
extern unsigned char etext;
int _start()
{
__label__ eprol;
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; /* r10 */
register char **targv;
register char **argv;
#ifdef lint
kfp = 0;
initcode = initcode = 0;
#else not lint
#define Entry_sp() \
({ int _spl__, _tmp1__; \
asm volatile("leal 4(%%ebp), %0" : "=r" (_spl__) : "r" (_tmp1__)); \
_spl__; })
kfp = (struct kframe *)Entry_sp();
#endif not lint
for (argv = targv = &kfp->kargv[0]; *targv++; /* void */)
/* void */ ;
if (targv >= (char **)(*argv))
--targv;
environ = targv;
if (mach_init_routine)
(void) mach_init_routine();
eprol:
#ifdef paranoid
/*
* The standard I/O library assumes that file descriptors 0, 1, and 2
* are open. If one of these descriptors is closed prior to the start
* of the process, I/O gets very confused. To avoid this problem, we
* insure that the first three file descriptors are open before calling
* main(). Normally this is undefined, as it adds two unnecessary
* system calls.
*/
do {
fd = open("/dev/null", 2);
} while (fd >= 0 && fd < 3);
close(fd);
#endif paranoid
if (_cthread_init_routine) {
int new_sp;
new_sp = (*_cthread_init_routine)();
if (new_sp) {
asm volatile("movl %0, %%esp" : : "g" (new_sp) );
}
}
if (_StrongBox_init_routine) (*_StrongBox_init_routine)();
if (_monstartup_routine) {
_monstartup_routine(&&eprol, &etext);
}
(* (_cthread_exit_routine ? _cthread_exit_routine : exit))
(main(kfp->kargc, argv, targv));
}
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