xref: /freebsd/sbin/fdisk/fdisk.c (revision 5521ff5a4d1929056e7ffc982fac3341ca54df7c)
1 /*
2  * Mach Operating System
3  * Copyright (c) 1992 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie Mellon
24  * the rights to redistribute these changes.
25  */
26 
27 #ifndef lint
28 static const char rcsid[] =
29   "$FreeBSD$";
30 #endif /* not lint */
31 
32 #include <sys/disklabel.h>
33 #include <sys/stat.h>
34 #include <ctype.h>
35 #include <fcntl.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 int iotest;
44 
45 #define LBUF 100
46 static char lbuf[LBUF];
47 
48 #define MBRSIGOFF	510
49 
50 /*
51  *
52  * Ported to 386bsd by Julian Elischer  Thu Oct 15 20:26:46 PDT 1992
53  *
54  * 14-Dec-89  Robert Baron (rvb) at Carnegie-Mellon University
55  *	Copyright (c) 1989	Robert. V. Baron
56  *	Created.
57  */
58 
59 #define Decimal(str, ans, tmp) if (decimal(str, &tmp, ans)) ans = tmp
60 #define Hex(str, ans, tmp) if (hex(str, &tmp, ans)) ans = tmp
61 #define String(str, ans, len) {char *z = ans; char **dflt = &z; if (string(str, dflt)) strncpy(ans, *dflt, len); }
62 
63 #define RoundCyl(x) ((((x) + cylsecs - 1) / cylsecs) * cylsecs)
64 
65 #define MAX_SEC_SIZE 2048	/* maximum section size that is supported */
66 #define MIN_SEC_SIZE 512	/* the sector size to start sensing at */
67 int secsize = 0;		/* the sensed sector size */
68 
69 const char *disk;
70 const char *disks[] =
71 {
72   "/dev/ad0", "/dev/da0", 0
73 };
74 
75 struct disklabel disklabel;		/* disk parameters */
76 
77 int cyls, sectors, heads, cylsecs, disksecs;
78 
79 struct mboot
80 {
81 	unsigned char padding[2]; /* force the longs to be long aligned */
82   	unsigned char *bootinst;  /* boot code */
83   	off_t bootinst_size;
84 	struct	dos_partition parts[4];
85 };
86 struct mboot mboot = {{0}, NULL, 0};
87 
88 #define ACTIVE 0x80
89 #define BOOT_MAGIC 0xAA55
90 
91 int dos_cyls;
92 int dos_heads;
93 int dos_sectors;
94 int dos_cylsecs;
95 
96 #define DOSSECT(s,c) ((s & 0x3f) | ((c >> 2) & 0xc0))
97 #define DOSCYL(c)	(c & 0xff)
98 static int partition = -1;
99 
100 
101 #define MAX_ARGS	10
102 
103 static int	current_line_number;
104 
105 static int	geom_processed = 0;
106 static int	part_processed = 0;
107 static int	active_processed = 0;
108 
109 
110 typedef struct cmd {
111     char		cmd;
112     int			n_args;
113     struct arg {
114 	char	argtype;
115 	int	arg_val;
116     }			args[MAX_ARGS];
117 } CMD;
118 
119 
120 static int B_flag  = 0;		/* replace boot code */
121 static int I_flag  = 0;		/* use entire disk for FreeBSD */
122 static int a_flag  = 0;		/* set active partition */
123 static char *b_flag = NULL;	/* path to boot code */
124 static int i_flag  = 0;		/* replace partition data */
125 static int u_flag  = 0;		/* update partition data */
126 static int s_flag  = 0;		/* Print a summary and exit */
127 static int t_flag  = 0;		/* test only, if f_flag is given */
128 static char *f_flag = NULL;	/* Read config info from file */
129 static int v_flag  = 0;		/* Be verbose */
130 
131 struct part_type
132 {
133  unsigned char type;
134  char *name;
135 }part_types[] =
136 {
137 	 {0x00, "unused"}
138 	,{0x01, "Primary DOS with 12 bit FAT"}
139 	,{0x02, "XENIX / filesystem"}
140 	,{0x03, "XENIX /usr filesystem"}
141 	,{0x04, "Primary DOS with 16 bit FAT (<= 32MB)"}
142 	,{0x05, "Extended DOS"}
143 	,{0x06, "Primary 'big' DOS (> 32MB)"}
144 	,{0x07, "OS/2 HPFS, NTFS, QNX-2 (16 bit) or Advanced UNIX"}
145 	,{0x08, "AIX filesystem"}
146 	,{0x09, "AIX boot partition or Coherent"}
147 	,{0x0A, "OS/2 Boot Manager or OPUS"}
148 	,{0x0B, "DOS or Windows 95 with 32 bit FAT"}
149 	,{0x0C, "DOS or Windows 95 with 32 bit FAT, LBA"}
150 	,{0x0E, "Primary 'big' DOS (> 32MB, LBA)"}
151 	,{0x0F, "Extended DOS, LBA"}
152 	,{0x10, "OPUS"}
153 	,{0x39, "plan9"}
154 	,{0x40, "VENIX 286"}
155 	,{0x4D, "QNX 4.2 Primary"}
156 	,{0x4E, "QNX 4.2 Secondary"}
157 	,{0x4F, "QNX 4.2 Tertiary"}
158 	,{0x50, "DM"}
159 	,{0x51, "DM"}
160 	,{0x52, "CP/M or Microport SysV/AT"}
161 	,{0x56, "GB"}
162 	,{0x61, "Speed"}
163 	,{0x63, "ISC UNIX, other System V/386, GNU HURD or Mach"}
164 	,{0x64, "Novell Netware 2.xx"}
165 	,{0x65, "Novell Netware 3.xx"}
166 	,{0x75, "PCIX"}
167 	,{0x80, "Minix 1.1 ... 1.4a"}
168 	,{0x81, "Minix 1.4b ... 1.5.10"}
169 	,{0x82, "Linux swap or Solaris x86"}
170 	,{0x83, "Linux filesystem"}
171 	,{0x93, "Amoeba filesystem"}
172 	,{0x94, "Amoeba bad block table"}
173 	,{0x9F, "BSD/OS"}
174 	,{0xA0, "Suspend to Disk"}
175 	,{0xA5, "FreeBSD/NetBSD/386BSD"}
176 	,{0xA6, "OpenBSD"}
177 	,{0xA7, "NEXTSTEP"}
178 	,{0xA9, "NetBSD"}
179 	,{0xB7, "BSDI BSD/386 filesystem"}
180 	,{0xB8, "BSDI BSD/386 swap"}
181 	,{0xDB, "Concurrent CPM or C.DOS or CTOS"}
182 	,{0xE1, "Speed"}
183 	,{0xE3, "Speed"}
184 	,{0xE4, "Speed"}
185 	,{0xF1, "Speed"}
186 	,{0xF2, "DOS 3.3+ Secondary"}
187 	,{0xF4, "Speed"}
188 	,{0xFF, "BBT (Bad Blocks Table)"}
189 };
190 
191 static void print_s0(int which);
192 static void print_part(int i);
193 static void init_sector0(unsigned long start);
194 static void init_boot(void);
195 static void change_part(int i);
196 static void print_params();
197 static void change_active(int which);
198 static void change_code();
199 static void get_params_to_use();
200 static void dos(int sec, int size, unsigned char *c, unsigned char *s,
201 		unsigned char *h);
202 static int open_disk(int u_flag);
203 static ssize_t read_disk(off_t sector, void *buf);
204 static ssize_t write_disk(off_t sector, void *buf);
205 static int get_params();
206 static int read_s0();
207 static int write_s0();
208 static int ok(char *str);
209 static int decimal(char *str, int *num, int deflt);
210 static char *get_type(int type);
211 static int read_config(char *config_file);
212 static void reset_boot(void);
213 static int sanitize_partition(struct dos_partition *);
214 static void usage(void);
215 #if 0
216 static int hex(char *str, int *num, int deflt);
217 static int string(char *str, char **ans);
218 #endif
219 
220 
221 int
222 main(int argc, char *argv[])
223 {
224 	int	c, i;
225 
226 	while ((c = getopt(argc, argv, "BIab:f:istuv1234")) != -1)
227 		switch (c) {
228 		case 'B':
229 			B_flag = 1;
230 			break;
231 		case 'I':
232 			I_flag = 1;
233 			break;
234 		case 'a':
235 			a_flag = 1;
236 			break;
237 		case 'b':
238 			b_flag = optarg;
239 			break;
240 		case 'f':
241 			f_flag = optarg;
242 			break;
243 		case 'i':
244 			i_flag = 1;
245 			break;
246 		case 's':
247 			s_flag = 1;
248 			break;
249 		case 't':
250 			t_flag = 1;
251 			break;
252 		case 'u':
253 			u_flag = 1;
254 			break;
255 		case 'v':
256 			v_flag = 1;
257 			break;
258 		case '1':
259 		case '2':
260 		case '3':
261 		case '4':
262 			partition = c - '0';
263 			break;
264 		default:
265 			usage();
266 		}
267 	if (f_flag || i_flag)
268 		u_flag = 1;
269 	if (t_flag)
270 		v_flag = 1;
271 	argc -= optind;
272 	argv += optind;
273 
274 	if (argc > 0)
275 	{
276 		static char realname[12];
277 
278 		if(strncmp(argv[0], "/dev", 4) == 0)
279 			disk = argv[0];
280 		else
281 		{
282 			snprintf(realname, 12, "/dev/%s", argv[0]);
283 			disk = realname;
284 		}
285 
286 		if (open_disk(u_flag) < 0)
287 			err(1, "cannot open disk %s", disk);
288 	}
289 	else
290 	{
291 		int rv = 0;
292 
293 		for(i = 0; disks[i]; i++)
294 		{
295 			disk = disks[i];
296 			rv = open_disk(u_flag);
297 			if(rv != -2) break;
298 		}
299 		if(rv < 0)
300 			err(1, "cannot open any disk");
301 	}
302 
303 	/* (abu)use mboot.bootinst to probe for the sector size */
304 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
305 		err(1, "cannot allocate buffer to determine disk sector size");
306 	read_disk(0, mboot.bootinst);
307 	free(mboot.bootinst);
308 	mboot.bootinst = NULL;
309 
310 	if (s_flag)
311 	{
312 		int i;
313 		struct dos_partition *partp;
314 
315 		if (read_s0())
316 			err(1, "read_s0");
317 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
318 		    dos_sectors);
319 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
320 		for (i = 0; i < NDOSPART; i++) {
321 			partp = ((struct dos_partition *) &mboot.parts) + i;
322 			if (partp->dp_start == 0 && partp->dp_size == 0)
323 				continue;
324 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", i + 1,
325 			    (u_long) partp->dp_start,
326 			    (u_long) partp->dp_size, partp->dp_typ,
327 			    partp->dp_flag);
328 		}
329 		exit(0);
330 	}
331 
332 	printf("******* Working on device %s *******\n",disk);
333 
334 	if (I_flag)
335 	{
336 		struct dos_partition *partp;
337 
338 		read_s0();
339 		reset_boot();
340 		partp = (struct dos_partition *) (&mboot.parts[0]);
341 		partp->dp_typ = DOSPTYP_386BSD;
342 		partp->dp_flag = ACTIVE;
343 		partp->dp_start = dos_sectors;
344 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs -
345 		    dos_sectors;
346 
347 		dos(partp->dp_start, partp->dp_size,
348 		    &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
349 		dos(partp->dp_start + partp->dp_size - 1, partp->dp_size,
350 		    &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
351 		if (v_flag)
352 			print_s0(-1);
353 		write_s0();
354 		exit(0);
355 	}
356 	if (f_flag)
357 	{
358 	    if (read_s0() || i_flag)
359 	    {
360 		reset_boot();
361 	    }
362 
363 	    if (!read_config(f_flag))
364 	    {
365 		exit(1);
366 	    }
367 	    if (v_flag)
368 	    {
369 		print_s0(-1);
370 	    }
371 	    if (!t_flag)
372 	    {
373 		write_s0();
374 	    }
375 	}
376 	else
377 	{
378 	    if(u_flag)
379 	    {
380 		get_params_to_use();
381 	    }
382 	    else
383 	    {
384 		print_params();
385 	    }
386 
387 	    if (read_s0())
388 		init_sector0(dos_sectors);
389 
390 	    printf("Media sector size is %d\n", secsize);
391 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
392 	    printf("Information from DOS bootblock is:\n");
393 	    if (partition == -1)
394 		for (i = 1; i <= NDOSPART; i++)
395 		    change_part(i);
396 	    else
397 		change_part(partition);
398 
399 	    if (u_flag || a_flag)
400 		change_active(partition);
401 
402 	    if (B_flag)
403 		change_code();
404 
405 	    if (u_flag || a_flag || B_flag) {
406 		if (!t_flag)
407 		{
408 		    printf("\nWe haven't changed the partition table yet.  ");
409 		    printf("This is your last chance.\n");
410 		}
411 		print_s0(-1);
412 		if (!t_flag)
413 		{
414 		    if (ok("Should we write new partition table?"))
415 			write_s0();
416 		}
417 		else
418 		{
419 		    printf("\n-t flag specified -- partition table not written.\n");
420 		}
421 	    }
422 	}
423 
424 	exit(0);
425 }
426 
427 static void
428 usage()
429 {
430 	fprintf(stderr, "%s%s",
431 		"usage: fdisk [-BIaistu] [-b bootcode] [-1234] [disk]\n",
432  		"       fdisk -f configfile [-itv] [disk]\n");
433         exit(1);
434 }
435 
436 static void
437 print_s0(int which)
438 {
439 int	i;
440 
441 	print_params();
442 	printf("Information from DOS bootblock is:\n");
443 	if (which == -1)
444 		for (i = 1; i <= NDOSPART; i++)
445 			printf("%d: ", i), print_part(i);
446 	else
447 		print_part(which);
448 }
449 
450 static struct dos_partition mtpart = { 0 };
451 
452 static void
453 print_part(int i)
454 {
455 	struct	  dos_partition *partp;
456 	u_int64_t part_mb;
457 
458 	partp = ((struct dos_partition *) &mboot.parts) + i - 1;
459 
460 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
461 		printf("<UNUSED>\n");
462 		return;
463 	}
464 	/*
465 	 * Be careful not to overflow.
466 	 */
467 	part_mb = partp->dp_size;
468 	part_mb *= secsize;
469 	part_mb /= (1024 * 1024);
470 	printf("sysid %d,(%s)\n", partp->dp_typ, get_type(partp->dp_typ));
471 	printf("    start %lu, size %lu (%qd Meg), flag %x%s\n",
472 		(u_long)partp->dp_start,
473 		(u_long)partp->dp_size,
474 		part_mb,
475 		partp->dp_flag,
476 		partp->dp_flag == ACTIVE ? " (active)" : "");
477 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
478 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
479 		,partp->dp_shd
480 		,DPSECT(partp->dp_ssect)
481 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
482 		,partp->dp_ehd
483 		,DPSECT(partp->dp_esect));
484 }
485 
486 
487 static void
488 init_boot(void)
489 {
490 	const char *fname;
491 	int fd, n;
492 	struct stat sb;
493 
494 	fname = b_flag ? b_flag : "/boot/mbr";
495 	if ((fd = open(fname, O_RDONLY)) == -1 ||
496 	    fstat(fd, &sb) == -1)
497 		err(1, "%s", fname);
498 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
499 		errx(1, "%s: length must be a multiple of sector size", fname);
500 	if (mboot.bootinst != NULL)
501 		free(mboot.bootinst);
502 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
503 		errx(1, "%s: unable to allocate read buffer", fname);
504 	if ((n = read(fd, mboot.bootinst, mboot.bootinst_size)) == -1 ||
505 	    close(fd))
506 		err(1, "%s", fname);
507 	if (n != mboot.bootinst_size)
508 		errx(1, "%s: short read", fname);
509 }
510 
511 
512 static void
513 init_sector0(unsigned long start)
514 {
515 struct dos_partition *partp = (struct dos_partition *) (&mboot.parts[3]);
516 
517 	init_boot();
518 
519 	partp->dp_typ = DOSPTYP_386BSD;
520 	partp->dp_flag = ACTIVE;
521 	start = ((start + dos_sectors - 1) / dos_sectors) * dos_sectors;
522 	if(start == 0)
523 		start = dos_sectors;
524 	partp->dp_start = start;
525 	partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
526 
527 	dos(partp->dp_start, partp->dp_size,
528 	    &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
529 	dos(partp->dp_start + partp->dp_size - 1, partp->dp_size,
530 	    &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
531 }
532 
533 static void
534 change_part(int i)
535 {
536 struct dos_partition *partp = ((struct dos_partition *) &mboot.parts) + i - 1;
537 
538     printf("The data for partition %d is:\n", i);
539     print_part(i);
540 
541     if (u_flag && ok("Do you want to change it?")) {
542 	int tmp;
543 
544 	if (i_flag) {
545 		bzero((char *)partp, sizeof (struct dos_partition));
546 		if (i == 4) {
547 			init_sector0(1);
548 			printf("\nThe static data for the DOS partition 4 has been reinitialized to:\n");
549 			print_part(i);
550 		}
551 	}
552 
553 	do {
554 		Decimal("sysid (165=FreeBSD)", partp->dp_typ, tmp);
555 		Decimal("start", partp->dp_start, tmp);
556 		Decimal("size", partp->dp_size, tmp);
557 
558 		if (ok("Explicitly specify beg/end address ?"))
559 		{
560 			int	tsec,tcyl,thd;
561 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
562 			thd = partp->dp_shd;
563 			tsec = DPSECT(partp->dp_ssect);
564 			Decimal("beginning cylinder", tcyl, tmp);
565 			Decimal("beginning head", thd, tmp);
566 			Decimal("beginning sector", tsec, tmp);
567 			partp->dp_scyl = DOSCYL(tcyl);
568 			partp->dp_ssect = DOSSECT(tsec,tcyl);
569 			partp->dp_shd = thd;
570 
571 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
572 			thd = partp->dp_ehd;
573 			tsec = DPSECT(partp->dp_esect);
574 			Decimal("ending cylinder", tcyl, tmp);
575 			Decimal("ending head", thd, tmp);
576 			Decimal("ending sector", tsec, tmp);
577 			partp->dp_ecyl = DOSCYL(tcyl);
578 			partp->dp_esect = DOSSECT(tsec,tcyl);
579 			partp->dp_ehd = thd;
580 		} else {
581 			if (!sanitize_partition(partp))
582 				partp->dp_typ = 0;
583 			dos(partp->dp_start, partp->dp_size,
584 			    &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
585 			dos(partp->dp_start + partp->dp_size - 1, partp->dp_size,
586 			    &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
587 		}
588 
589 		print_part(i);
590 	} while (!ok("Are we happy with this entry?"));
591     }
592 }
593 
594 static void
595 print_params()
596 {
597 	printf("parameters extracted from in-core disklabel are:\n");
598 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
599 			,cyls,heads,sectors,cylsecs);
600 	if((dos_sectors > 63) || (dos_cyls > 1023) || (dos_heads > 255))
601 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
602 	printf("parameters to be used for BIOS calculations are:\n");
603 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
604 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
605 }
606 
607 static void
608 change_active(int which)
609 {
610 int i;
611 int active = 4, tmp;
612 struct dos_partition *partp = ((struct dos_partition *) &mboot.parts);
613 
614 	if (a_flag && which != -1)
615 		active = which;
616 	if (!ok("Do you want to change the active partition?"))
617 		return;
618 setactive:
619 	active = 4;
620 	do {
621 		Decimal("active partition", active, tmp);
622 		if (active < 1 || 4 < active) {
623 			printf("Active partition number must be in range 1-4."
624 					"  Try again.\n");
625 			goto setactive;
626 		}
627 	} while (!ok("Are you happy with this choice"));
628 	for (i = 0; i < NDOSPART; i++)
629 		partp[i].dp_flag = 0;
630 	if (active > 0 && active <= NDOSPART)
631 		partp[active-1].dp_flag = ACTIVE;
632 }
633 
634 static void
635 change_code()
636 {
637 	if (ok("Do you want to change the boot code?"))
638 		init_boot();
639 }
640 
641 void
642 get_params_to_use()
643 {
644 	int	tmp;
645 	print_params();
646 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
647 	{
648 		do
649 		{
650 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp);
651 			Decimal("BIOS's idea of #heads", dos_heads, tmp);
652 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp);
653 			dos_cylsecs = dos_heads * dos_sectors;
654 			print_params();
655 		}
656 		while(!ok("Are you happy with this choice"));
657 	}
658 }
659 
660 
661 /***********************************************\
662 * Change real numbers into strange dos numbers	*
663 \***********************************************/
664 static void
665 dos(sec, size, c, s, h)
666 int sec, size;
667 unsigned char *c, *s, *h;
668 {
669 int cy;
670 int hd;
671 
672 	if (sec == 0 && size == 0) {
673 		*s = *c = *h = 0;
674 		return;
675 	}
676 
677 	cy = sec / ( dos_cylsecs );
678 	sec = sec - cy * ( dos_cylsecs );
679 
680 	hd = sec / dos_sectors;
681 	sec = (sec - hd * dos_sectors) + 1;
682 
683 	*h = hd;
684 	*c = cy & 0xff;
685 	*s = (sec & 0x3f) | ( (cy & 0x300) >> 2);
686 }
687 
688 int fd;
689 
690 	/* Getting device status */
691 
692 static int
693 open_disk(int u_flag)
694 {
695 	struct stat 	st;
696 
697 	if (stat(disk, &st) == -1) {
698 		if (errno == ENOENT)
699 			return -2;
700 		warnx("can't get file status of %s", disk);
701 		return -1;
702 	}
703 	if ( !(st.st_mode & S_IFCHR) )
704 		warnx("device %s is not character special", disk);
705 	if ((fd = open(disk,
706 	    a_flag || I_flag || B_flag || u_flag ? O_RDWR : O_RDONLY)) == -1) {
707 		if(errno == ENXIO)
708 			return -2;
709 		warnx("can't open device %s", disk);
710 		return -1;
711 	}
712 	if (get_params(0) == -1) {
713 		warnx("can't get disk parameters on %s", disk);
714 		return -1;
715 	}
716 	return fd;
717 }
718 
719 static ssize_t
720 read_disk(off_t sector, void *buf)
721 {
722 	lseek(fd,(sector * 512), 0);
723 	if( secsize == 0 )
724 		for( secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE; secsize *= 2 )
725 			{
726 			/* try the read */
727 			int size = read(fd, buf, secsize);
728 			if( size == secsize )
729 				/* it worked so return */
730 				return secsize;
731 			}
732 	else
733 		return read( fd, buf, secsize );
734 
735 	/* we failed to read at any of the sizes */
736 	return -1;
737 }
738 
739 static ssize_t
740 write_disk(off_t sector, void *buf)
741 {
742 	lseek(fd,(sector * 512), 0);
743 	/* write out in the size that the read_disk found worked */
744 	return write(fd, buf, secsize);
745 }
746 
747 static int
748 get_params()
749 {
750 
751     if (ioctl(fd, DIOCGDINFO, &disklabel) == -1) {
752 	warnx("can't get disk parameters on %s; supplying dummy ones", disk);
753 	dos_cyls = cyls = 1;
754 	dos_heads = heads = 1;
755 	dos_sectors = sectors = 1;
756 	dos_cylsecs = cylsecs = heads * sectors;
757 	disksecs = cyls * heads * sectors;
758 	return disksecs;
759     }
760 
761     dos_cyls = cyls = disklabel.d_ncylinders;
762     dos_heads = heads = disklabel.d_ntracks;
763     dos_sectors = sectors = disklabel.d_nsectors;
764     dos_cylsecs = cylsecs = heads * sectors;
765     disksecs = cyls * heads * sectors;
766 
767     return (disksecs);
768 }
769 
770 
771 static int
772 read_s0()
773 {
774 	mboot.bootinst_size = secsize;
775 	if (mboot.bootinst != NULL)
776 		free(mboot.bootinst);
777 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
778 		warnx("unable to allocate buffer to read fdisk "
779 		      "partition table");
780 		return -1;
781 	}
782 	if (read_disk(0, mboot.bootinst) == -1) {
783 		warnx("can't read fdisk partition table");
784 		return -1;
785 	}
786 	if (*(uint16_t *)&mboot.bootinst[MBRSIGOFF] != BOOT_MAGIC) {
787 		warnx("invalid fdisk partition table found");
788 		/* So should we initialize things */
789 		return -1;
790 	}
791 	memcpy(mboot.parts, &mboot.bootinst[DOSPARTOFF], sizeof(mboot.parts));
792 	return 0;
793 }
794 
795 static int
796 write_s0()
797 {
798 #ifdef NOT_NOW
799 	int	flag;
800 #endif
801 	int	sector;
802 
803 	if (iotest) {
804 		print_s0(-1);
805 		return 0;
806 	}
807 	memcpy(&mboot.bootinst[DOSPARTOFF], mboot.parts, sizeof(mboot.parts));
808 	/*
809 	 * write enable label sector before write (if necessary),
810 	 * disable after writing.
811 	 * needed if the disklabel protected area also protects
812 	 * sector 0. (e.g. empty disk)
813 	 */
814 #ifdef NOT_NOW
815 	flag = 1;
816 	if (ioctl(fd, DIOCWLABEL, &flag) < 0)
817 		warn("ioctl DIOCWLABEL");
818 #endif
819 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
820 		if (write_disk(sector,
821 			       &mboot.bootinst[sector * secsize]) == -1) {
822 			warn("can't write fdisk partition table");
823 			return -1;
824 #ifdef NOT_NOW
825 			flag = 0;
826 			(void) ioctl(fd, DIOCWLABEL, &flag);
827 #endif
828 		}
829 #ifdef NOT_NOW
830 	flag = 0;
831 	(void) ioctl(fd, DIOCWLABEL, &flag);
832 #endif
833 	return(0);
834 }
835 
836 
837 static int
838 ok(str)
839 char *str;
840 {
841 	printf("%s [n] ", str);
842 	fgets(lbuf, LBUF, stdin);
843 	lbuf[strlen(lbuf)-1] = 0;
844 
845 	if (*lbuf &&
846 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
847 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
848 		return 1;
849 	else
850 		return 0;
851 }
852 
853 static int
854 decimal(char *str, int *num, int deflt)
855 {
856 int acc = 0, c;
857 char *cp;
858 
859 	while (1) {
860 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
861 		fgets(lbuf, LBUF, stdin);
862 		lbuf[strlen(lbuf)-1] = 0;
863 
864 		if (!*lbuf)
865 			return 0;
866 
867 		cp = lbuf;
868 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
869 		if (!c)
870 			return 0;
871 		while ((c = *cp++)) {
872 			if (c <= '9' && c >= '0')
873 				acc = acc * 10 + c - '0';
874 			else
875 				break;
876 		}
877 		if (c == ' ' || c == '\t')
878 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
879 		if (!c) {
880 			*num = acc;
881 			return 1;
882 		} else
883 			printf("%s is an invalid decimal number.  Try again.\n",
884 				lbuf);
885 	}
886 
887 }
888 
889 #if 0
890 static int
891 hex(char *str, int *num, int deflt)
892 {
893 int acc = 0, c;
894 char *cp;
895 
896 	while (1) {
897 		printf("Supply a hex value for \"%s\" [%x] ", str, deflt);
898 		fgets(lbuf, LBUF, stdin);
899 		lbuf[strlen(lbuf)-1] = 0;
900 
901 		if (!*lbuf)
902 			return 0;
903 
904 		cp = lbuf;
905 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
906 		if (!c)
907 			return 0;
908 		while ((c = *cp++)) {
909 			if (c <= '9' && c >= '0')
910 				acc = (acc << 4) + c - '0';
911 			else if (c <= 'f' && c >= 'a')
912 				acc = (acc << 4) + c - 'a' + 10;
913 			else if (c <= 'F' && c >= 'A')
914 				acc = (acc << 4) + c - 'A' + 10;
915 			else
916 				break;
917 		}
918 		if (c == ' ' || c == '\t')
919 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
920 		if (!c) {
921 			*num = acc;
922 			return 1;
923 		} else
924 			printf("%s is an invalid hex number.  Try again.\n",
925 				lbuf);
926 	}
927 
928 }
929 
930 static int
931 string(char *str, char **ans)
932 {
933 int c;
934 char *cp = lbuf;
935 
936 	while (1) {
937 		printf("Supply a string value for \"%s\" [%s] ", str, *ans);
938 		fgets(lbuf, LBUF, stdin);
939 		lbuf[strlen(lbuf)-1] = 0;
940 
941 		if (!*lbuf)
942 			return 0;
943 
944 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
945 		if (c == '"') {
946 			c = *++cp;
947 			*ans = cp;
948 			while ((c = *cp) && c != '"') cp++;
949 		} else {
950 			*ans = cp;
951 			while ((c = *cp) && c != ' ' && c != '\t') cp++;
952 		}
953 
954 		if (c)
955 			*cp = 0;
956 		return 1;
957 	}
958 }
959 #endif
960 
961 static char *
962 get_type(int type)
963 {
964 	int	numentries = (sizeof(part_types)/sizeof(struct part_type));
965 	int	counter = 0;
966 	struct	part_type *ptr = part_types;
967 
968 
969 	while(counter < numentries)
970 	{
971 		if(ptr->type == type)
972 		{
973 			return(ptr->name);
974 		}
975 		ptr++;
976 		counter++;
977 	}
978 	return("unknown");
979 }
980 
981 
982 static void
983 parse_config_line(line, command)
984     char	*line;
985     CMD		*command;
986 {
987     char	*cp, *end;
988 
989     cp = line;
990     while (1)	/* dirty trick used to insure one exit point for this
991 		   function */
992     {
993 	memset(command, 0, sizeof(*command));
994 
995 	while (isspace(*cp)) ++cp;
996 	if (*cp == '\0' || *cp == '#')
997 	{
998 	    break;
999 	}
1000 	command->cmd = *cp++;
1001 
1002 	/*
1003 	 * Parse args
1004 	 */
1005 	while (1)
1006 	{
1007 	    while (isspace(*cp)) ++cp;
1008 	    if (*cp == '#')
1009 	    {
1010 		break;		/* found comment */
1011 	    }
1012 	    if (isalpha(*cp))
1013 	    {
1014 		command->args[command->n_args].argtype = *cp++;
1015 	    }
1016 	    if (!isdigit(*cp))
1017 	    {
1018 		break;		/* assume end of line */
1019 	    }
1020 	    end = NULL;
1021 	    command->args[command->n_args].arg_val = strtol(cp, &end, 0);
1022 	    if (cp == end)
1023 	    {
1024 		break;		/* couldn't parse number */
1025 	    }
1026 	    cp = end;
1027 	    command->n_args++;
1028 	}
1029 	break;
1030     }
1031 }
1032 
1033 
1034 static int
1035 process_geometry(command)
1036     CMD		*command;
1037 {
1038     int		status = 1, i;
1039 
1040     while (1)
1041     {
1042 	geom_processed = 1;
1043 	if (part_processed)
1044 	{
1045 	    warnx(
1046 	"ERROR line %d: the geometry specification line must occur before\n\
1047     all partition specifications",
1048 		    current_line_number);
1049 	    status = 0;
1050 	    break;
1051 	}
1052 	if (command->n_args != 3)
1053 	{
1054 	    warnx("ERROR line %d: incorrect number of geometry args",
1055 		    current_line_number);
1056 	    status = 0;
1057 	    break;
1058 	}
1059 	dos_cyls = -1;
1060 	dos_heads = -1;
1061 	dos_sectors = -1;
1062 	for (i = 0; i < 3; ++i)
1063 	{
1064 	    switch (command->args[i].argtype)
1065 	    {
1066 	    case 'c':
1067 		dos_cyls = command->args[i].arg_val;
1068 		break;
1069 	    case 'h':
1070 		dos_heads = command->args[i].arg_val;
1071 		break;
1072 	    case 's':
1073 		dos_sectors = command->args[i].arg_val;
1074 		break;
1075 	    default:
1076 		warnx(
1077 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1078 			current_line_number, command->args[i].argtype,
1079 			command->args[i].argtype);
1080 		status = 0;
1081 		break;
1082 	    }
1083 	}
1084 	if (status == 0)
1085 	{
1086 	    break;
1087 	}
1088 
1089 	dos_cylsecs = dos_heads * dos_sectors;
1090 
1091 	/*
1092 	 * Do sanity checks on parameter values
1093 	 */
1094 	if (dos_cyls < 0)
1095 	{
1096 	    warnx("ERROR line %d: number of cylinders not specified",
1097 		    current_line_number);
1098 	    status = 0;
1099 	}
1100 	if (dos_cyls == 0 || dos_cyls > 1024)
1101 	{
1102 	    warnx(
1103 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1104     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1105     is dedicated to FreeBSD)",
1106 		    current_line_number, dos_cyls);
1107 	}
1108 
1109 	if (dos_heads < 0)
1110 	{
1111 	    warnx("ERROR line %d: number of heads not specified",
1112 		    current_line_number);
1113 	    status = 0;
1114 	}
1115 	else if (dos_heads < 1 || dos_heads > 256)
1116 	{
1117 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1118 		    current_line_number);
1119 	    status = 0;
1120 	}
1121 
1122 	if (dos_sectors < 0)
1123 	{
1124 	    warnx("ERROR line %d: number of sectors not specified",
1125 		    current_line_number);
1126 	    status = 0;
1127 	}
1128 	else if (dos_sectors < 1 || dos_sectors > 63)
1129 	{
1130 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1131 		    current_line_number);
1132 	    status = 0;
1133 	}
1134 
1135 	break;
1136     }
1137     return (status);
1138 }
1139 
1140 
1141 static int
1142 process_partition(command)
1143     CMD		*command;
1144 {
1145     int				status = 0, partition;
1146     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1147     u_int32_t			adj_size, max_end;
1148     struct dos_partition	*partp;
1149 
1150     while (1)
1151     {
1152 	part_processed = 1;
1153 	if (command->n_args != 4)
1154 	{
1155 	    warnx("ERROR line %d: incorrect number of partition args",
1156 		    current_line_number);
1157 	    break;
1158 	}
1159 	partition = command->args[0].arg_val;
1160 	if (partition < 1 || partition > 4)
1161 	{
1162 	    warnx("ERROR line %d: invalid partition number %d",
1163 		    current_line_number, partition);
1164 	    break;
1165 	}
1166 	partp = ((struct dos_partition *) &mboot.parts) + partition - 1;
1167 	bzero((char *)partp, sizeof (struct dos_partition));
1168 	partp->dp_typ = command->args[1].arg_val;
1169 	partp->dp_start = command->args[2].arg_val;
1170 	partp->dp_size = command->args[3].arg_val;
1171 	max_end = partp->dp_start + partp->dp_size;
1172 
1173 	if (partp->dp_typ == 0)
1174 	{
1175 	    /*
1176 	     * Get out, the partition is marked as unused.
1177 	     */
1178 	    /*
1179 	     * Insure that it's unused.
1180 	     */
1181 	    bzero((char *)partp, sizeof (struct dos_partition));
1182 	    status = 1;
1183 	    break;
1184 	}
1185 
1186 	/*
1187 	 * Adjust start upwards, if necessary, to fall on an head boundary.
1188 	 */
1189 	if (partp->dp_start % dos_sectors != 0)
1190 	{
1191 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1192 	    if (max_end < dos_sectors ||
1193 		prev_head_boundary > max_end - dos_sectors)
1194 	    {
1195 		/*
1196 		 * Can't go past end of partition
1197 		 */
1198 		warnx(
1199 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1200     a head boundary",
1201 			current_line_number, partition);
1202 		break;
1203 	    }
1204 	    warnx(
1205 	"WARNING: adjusting start offset of partition %d\n\
1206     from %u to %u, to fall on a head boundary",
1207 		    partition, (u_int)partp->dp_start,
1208 		    (u_int)(prev_head_boundary + dos_sectors));
1209 	    partp->dp_start = prev_head_boundary + dos_sectors;
1210 	}
1211 
1212 	/*
1213 	 * Adjust size downwards, if necessary, to fall on a cylinder
1214 	 * boundary.
1215 	 */
1216 	prev_cyl_boundary =
1217 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1218 	if (prev_cyl_boundary > partp->dp_start)
1219 	    adj_size = prev_cyl_boundary - partp->dp_start;
1220 	else
1221 	{
1222 	    warnx(
1223 	"ERROR: could not adjust partition to start on a head boundary\n\
1224     and end on a cylinder boundary.");
1225 	    return (0);
1226 	}
1227 	if (adj_size != partp->dp_size)
1228 	{
1229 	    warnx(
1230 	"WARNING: adjusting size of partition %d from %u to %u\n\
1231     to end on a cylinder boundary",
1232 		    partition, (u_int)partp->dp_size, (u_int)adj_size);
1233 	    partp->dp_size = adj_size;
1234 	}
1235 	if (partp->dp_size == 0)
1236 	{
1237 	    warnx("ERROR line %d: size for partition %d is zero",
1238 		    current_line_number, partition);
1239 	    break;
1240 	}
1241 
1242 	dos(partp->dp_start, partp->dp_size,
1243 	    &partp->dp_scyl, &partp->dp_ssect, &partp->dp_shd);
1244 	dos(partp->dp_start+partp->dp_size - 1, partp->dp_size,
1245 	    &partp->dp_ecyl, &partp->dp_esect, &partp->dp_ehd);
1246 	status = 1;
1247 	break;
1248     }
1249     return (status);
1250 }
1251 
1252 
1253 static int
1254 process_active(command)
1255     CMD		*command;
1256 {
1257     int				status = 0, partition, i;
1258     struct dos_partition	*partp;
1259 
1260     while (1)
1261     {
1262 	active_processed = 1;
1263 	if (command->n_args != 1)
1264 	{
1265 	    warnx("ERROR line %d: incorrect number of active args",
1266 		    current_line_number);
1267 	    status = 0;
1268 	    break;
1269 	}
1270 	partition = command->args[0].arg_val;
1271 	if (partition < 1 || partition > 4)
1272 	{
1273 	    warnx("ERROR line %d: invalid partition number %d",
1274 		    current_line_number, partition);
1275 	    break;
1276 	}
1277 	/*
1278 	 * Reset active partition
1279 	 */
1280 	partp = ((struct dos_partition *) &mboot.parts);
1281 	for (i = 0; i < NDOSPART; i++)
1282 	    partp[i].dp_flag = 0;
1283 	partp[partition-1].dp_flag = ACTIVE;
1284 
1285 	status = 1;
1286 	break;
1287     }
1288     return (status);
1289 }
1290 
1291 
1292 static int
1293 process_line(line)
1294     char	*line;
1295 {
1296     CMD		command;
1297     int		status = 1;
1298 
1299     while (1)
1300     {
1301 	parse_config_line(line, &command);
1302 	switch (command.cmd)
1303 	{
1304 	case 0:
1305 	    /*
1306 	     * Comment or blank line
1307 	     */
1308 	    break;
1309 	case 'g':
1310 	    /*
1311 	     * Set geometry
1312 	     */
1313 	    status = process_geometry(&command);
1314 	    break;
1315 	case 'p':
1316 	    status = process_partition(&command);
1317 	    break;
1318 	case 'a':
1319 	    status = process_active(&command);
1320 	    break;
1321 	default:
1322 	    status = 0;
1323 	    break;
1324 	}
1325 	break;
1326     }
1327     return (status);
1328 }
1329 
1330 
1331 static int
1332 read_config(config_file)
1333     char *config_file;
1334 {
1335     FILE	*fp = NULL;
1336     int		status = 1;
1337     char	buf[1010];
1338 
1339     while (1)	/* dirty trick used to insure one exit point for this
1340 		   function */
1341     {
1342 	if (strcmp(config_file, "-") != 0)
1343 	{
1344 	    /*
1345 	     * We're not reading from stdin
1346 	     */
1347 	    if ((fp = fopen(config_file, "r")) == NULL)
1348 	    {
1349 		status = 0;
1350 		break;
1351 	    }
1352 	}
1353 	else
1354 	{
1355 	    fp = stdin;
1356 	}
1357 	current_line_number = 0;
1358 	while (!feof(fp))
1359 	{
1360 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1361 	    {
1362 		break;
1363 	    }
1364 	    ++current_line_number;
1365 	    status = process_line(buf);
1366 	    if (status == 0)
1367 	    {
1368 		break;
1369 	    }
1370 	}
1371 	break;
1372     }
1373     if (fp)
1374     {
1375 	/*
1376 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1377 	 */
1378 	fclose(fp);
1379     }
1380     return (status);
1381 }
1382 
1383 
1384 static void
1385 reset_boot(void)
1386 {
1387     int				i;
1388     struct dos_partition	*partp;
1389 
1390     init_boot();
1391     for (i = 0; i < 4; ++i)
1392     {
1393 	partp = ((struct dos_partition *) &mboot.parts) + i;
1394 	bzero((char *)partp, sizeof (struct dos_partition));
1395     }
1396 }
1397 
1398 static int
1399 sanitize_partition(partp)
1400     struct dos_partition	*partp;
1401 {
1402     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1403     u_int32_t			adj_size, max_end;
1404 
1405     max_end = partp->dp_start + partp->dp_size;
1406 
1407     /*
1408      * Adjust start upwards, if necessary, to fall on an head boundary.
1409      */
1410     if (partp->dp_start % dos_sectors != 0) {
1411 	prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1412 	if (max_end < dos_sectors ||
1413 	    prev_head_boundary > max_end - dos_sectors) {
1414 	    /*
1415 	     * Can't go past end of partition
1416 	     */
1417 	    warnx(
1418     "ERROR: unable to adjust start of partition to fall on a head boundary");
1419 	    return (0);
1420         }
1421 	warnx(
1422     "WARNING: adjusting start offset of partition\n\
1423     to %u to fall on a head boundary",
1424 	    (u_int)(prev_head_boundary + dos_sectors));
1425 	partp->dp_start = prev_head_boundary + dos_sectors;
1426     }
1427 
1428     /*
1429      * Adjust size downwards, if necessary, to fall on a cylinder
1430      * boundary.
1431      */
1432     prev_cyl_boundary = ((partp->dp_start + partp->dp_size) / dos_cylsecs) *
1433 	dos_cylsecs;
1434     if (prev_cyl_boundary > partp->dp_start)
1435 	adj_size = prev_cyl_boundary - partp->dp_start;
1436     else
1437     {
1438 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1439     and end on a cylinder boundary.");
1440 	return (0);
1441     }
1442     if (adj_size != partp->dp_size) {
1443 	warnx(
1444     "WARNING: adjusting size of partition to %u to end on a\n\
1445     cylinder boundary",
1446 	    (u_int)adj_size);
1447 	partp->dp_size = adj_size;
1448     }
1449     if (partp->dp_size == 0) {
1450 	warnx("ERROR: size for partition is zero");
1451 	return (0);
1452     }
1453 
1454     return (1);
1455 }
1456