/*
 * Copyright (c) 1992 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)boot.c	7.7 (Berkeley) 03/27/93
 */

#include <sys/param.h>
#include <sys/exec.h>

char	line[1024];

/*
 * This gets arguments from the PROM, calls other routines to open
 * and load the program to boot, and then transfers execution to that
 * new program.
 * Argv[0] should be something like "rz(0,0,0)vmunix" on a DECstation 3100.
 * Argv[0,1] should be something like "boot 5/rz0/vmunix" on a DECstation 5000.
 * The argument "-a" means vmunix should do an automatic reboot.
 */
void
main(argc, argv)
	int argc;
	char **argv;
{
	register char *cp;
	int ask, entry;

#ifdef JUSTASK
	ask = 1;
#else
	ask = 0;
#ifdef DS3100
	for (cp = argv[0]; *cp; cp++) {
		if (*cp == ')' && cp[1]) {
			cp = argv[0];
			goto fnd;
		}
	}
#endif
#ifdef DS5000
	if (argc > 1) {
		argc--;
		argv++;
		/* look for second '/' as in '5/rz0/vmunix' */
		for (cp = argv[0]; *cp; cp++) {
			if (*cp == '/') {
				while (*++cp) {
					if (*cp == '/' && cp[1]) {
						cp = argv[0];
						goto fnd;
					}
				}
			}
		}
	}
#endif
	ask = 1;
fnd:
	;
#endif /* JUSTASK */
	for (;;) {
		if (ask) {
			printf("Boot: ");
			gets(line);
			if (line[0] == '\0')
				continue;
			cp = line;
			argv[0] = cp;
			argc = 1;
		} else
			printf("Boot: %s\n", cp);
		entry = loadfile(cp);
		if (entry != -1)
			break;
		ask = 1;
	}
	printf("Starting at 0x%x\n\n", entry);
	((void (*)())entry)(argc, argv);
}

/*
 * Open 'filename', read in program and return the entry point or -1 if error.
 */
loadfile(fname)
	register char *fname;
{
	register struct devices *dp;
	register int fd, i, n;
	struct exec aout;

	if ((fd = open(fname, 0)) < 0) {
		goto err;
	}

	/* read the exec header */
	i = read(fd, (char *)&aout, sizeof(aout));
	if (i != sizeof(aout)) {
		goto cerr;
	} else if (aout.a_magic != OMAGIC) {
		goto cerr;
	}

	/* read the code and initialized data */
	printf("Size: %d+%d", aout.a_text, aout.a_data);
	if (lseek(fd, (off_t)N_TXTOFF(aout), 0) < 0) {
		goto cerr;
	}
	i = aout.a_text + aout.a_data;
	n = read(fd, (char *)aout.a_entry, i);
#ifndef SMALL
	(void) close(fd);
#endif
	if (n < 0) {
		goto err;
	} else if (n != i) {
		goto err;
	}

	/* kernel will zero out its own bss */
	n = aout.a_bss;
	printf("+%d\n", n);

	return ((int)aout.a_entry);

cerr:
#ifndef SMALL
	(void) close(fd);
#endif
err:
	printf("Can't boot '%s'\n", fname);
	return (-1);
}