124 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
| /*-
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|  * Copyright (c) 1990 The Regents of the University of California.
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|  * All rights reserved.
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|  *
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|  * Redistribution and use in source and binary forms, with or without
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|  * modification, are permitted provided that the following conditions
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|  * are met:
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|  * 1. Redistributions of source code must retain the above copyright
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|  *    notice, this list of conditions and the following disclaimer.
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|  * 2. Redistributions in binary form must reproduce the above copyright
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|  *    notice, this list of conditions and the following disclaimer in the
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|  *    documentation and/or other materials provided with the distribution.
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|  * 3. Neither the name of the University nor the names of its contributors
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|  *    may be used to endorse or promote products derived from this software
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|  *    without specific prior written permission.
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|  *
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|  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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|  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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|  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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|  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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|  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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|  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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|  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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|  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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|  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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|  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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|  * SUCH DAMAGE.
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|  */
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| 
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| #if defined(LIBC_SCCS) && !defined(lint)
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| static char sccsid[] = "@(#)crt0.c	5.7 (Berkeley) 7/3/91";
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| #endif /* LIBC_SCCS and not lint */
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| 
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| /*
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|  *	C start up routine.
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|  *	Robert Henry, UCB, 20 Oct 81
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|  *
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|  *	We make the following (true) assumption:
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|  *	1) The only register variable that we can trust is ebp,
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|  *	which points to the base of the kernel calling frame.
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|  */
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| 
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| char **environ = (char **)0;
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| static int fd;
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| 
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| /*
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| asm(".text");
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| asm(".long 0xc000c000");
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| */
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| extern	unsigned char	etext;
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| extern	unsigned char	eprol asm ("eprol");
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| /* extern			start() asm("start"); */
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| 
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| _start(int arg)
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| {
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| 	struct kframe {
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| 		int	kargc;
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| 		char	*kargv[1];	/* size depends on kargc */
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| 		char	kargstr[1];	/* size varies */
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| 		char	kenvstr[1];	/* size varies */
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| 	};
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| 	/*
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| 	 *	ALL REGISTER VARIABLES!!!
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| 	 */
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| 	register struct kframe *kfp;	/* r10 */
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| 	register char **targv;
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| 	register char **argv;
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| 	extern int errno;
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| 	extern void _mcleanup();
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| 
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| #ifdef lint
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| 	kfp = 0;
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| 	initcode = initcode = 0;
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| #else not lint
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| # if 0
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| 	asm("lea 4(%ebp),%ebx");	/* catch it quick */
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| # else
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| 	kfp = (struct kframe *)&(((int *)(&arg))[-1]);
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| # endif
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| #endif not lint
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| 	for (argv = targv = &kfp->kargv[0]; *targv++; /* void */)
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| 		/* void */ ;
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| 	if (targv >= (char **)(*argv))
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| 		--targv;
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| 	environ = targv;
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| asm("eprol:");
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| 
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| #ifdef paranoid
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| 	/*
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| 	 * The standard I/O library assumes that file descriptors 0, 1, and 2
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| 	 * are open. If one of these descriptors is closed prior to the start 
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| 	 * of the process, I/O gets very confused. To avoid this problem, we
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| 	 * insure that the first three file descriptors are open before calling
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| 	 * main(). Normally this is undefined, as it adds two unnecessary
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| 	 * system calls.
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| 	 */
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| 	do	{
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| 		fd = open("/dev/null", 2);
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| 	} while (fd >= 0 && fd < 3);
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| 	close(fd);
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| #endif paranoid
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| 
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| #ifdef MCRT0
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| 	atexit(_mcleanup);
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| 	monstartup(&eprol, &etext);
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| #endif MCRT0
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| 	errno = 0;
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| 	exit(main(kfp->kargc, argv, environ));
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| }
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| 
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| #ifdef CRT0
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| /*
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|  * null mcount and moncontrol,
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|  * just in case some routine is compiled for profiling
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|  */
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| moncontrol(val)
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| 	int val;
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| {
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| 
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| }
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| asm(".globl mcount");
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| asm("mcount: ret");
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| #endif CRT0
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