xref: /freebsd/sbin/fdisk/fdisk.c (revision cacdd70cc751fb68dec4b86c5e5b8c969b6e26ef)
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 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/disk.h>
31 #include <sys/disklabel.h>
32 #include <sys/diskmbr.h>
33 #include <sys/endian.h>
34 #include <sys/param.h>
35 #include <sys/stat.h>
36 #include <sys/mount.h>
37 #include <ctype.h>
38 #include <fcntl.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <libgeom.h>
42 #include <paths.h>
43 #include <regex.h>
44 #include <stdint.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 int iotest;
51 
52 #define LBUF 100
53 static char lbuf[LBUF];
54 
55 /*
56  *
57  * Ported to 386bsd by Julian Elischer  Thu Oct 15 20:26:46 PDT 1992
58  *
59  * 14-Dec-89  Robert Baron (rvb) at Carnegie-Mellon University
60  *	Copyright (c) 1989	Robert. V. Baron
61  *	Created.
62  */
63 
64 #define Decimal(str, ans, tmp) if (decimal(str, &tmp, ans)) ans = tmp
65 
66 #define RoundCyl(x) ((((x) + cylsecs - 1) / cylsecs) * cylsecs)
67 
68 #define MAX_SEC_SIZE 2048	/* maximum section size that is supported */
69 #define MIN_SEC_SIZE 512	/* the sector size to start sensing at */
70 static int secsize = 0;		/* the sensed sector size */
71 
72 static char *disk;
73 
74 static int cyls, sectors, heads, cylsecs, disksecs;
75 
76 struct mboot {
77 	unsigned char padding[2]; /* force the longs to be long aligned */
78 	unsigned char *bootinst;  /* boot code */
79 	off_t bootinst_size;
80 	struct	dos_partition parts[NDOSPART];
81 };
82 
83 static struct mboot mboot;
84 static int fd;
85 
86 #define ACTIVE 0x80
87 
88 static uint dos_cyls;
89 static uint dos_heads;
90 static uint dos_sectors;
91 static uint dos_cylsecs;
92 
93 #define DOSSECT(s,c) ((s & 0x3f) | ((c >> 2) & 0xc0))
94 #define DOSCYL(c)	(c & 0xff)
95 
96 #define MAX_ARGS	10
97 
98 static int	current_line_number;
99 
100 static int	geom_processed = 0;
101 static int	part_processed = 0;
102 static int	active_processed = 0;
103 
104 typedef struct cmd {
105     char		cmd;
106     int			n_args;
107     struct arg {
108 	char	argtype;
109 	int	arg_val;
110     }			args[MAX_ARGS];
111 } CMD;
112 
113 static int B_flag  = 0;		/* replace boot code */
114 static int I_flag  = 0;		/* use entire disk for FreeBSD */
115 static int a_flag  = 0;		/* set active partition */
116 static char *b_flag = NULL;	/* path to boot code */
117 static int i_flag  = 0;		/* replace partition data */
118 static int q_flag  = 0;		/* Be quiet */
119 static int u_flag  = 0;		/* update partition data */
120 static int s_flag  = 0;		/* Print a summary and exit */
121 static int t_flag  = 0;		/* test only */
122 static char *f_flag = NULL;	/* Read config info from file */
123 static int v_flag  = 0;		/* Be verbose */
124 static int print_config_flag = 0;
125 
126 static struct part_type
127 {
128 	unsigned char type;
129 	const char *name;
130 } part_types[] = {
131 	 {0x00, "unused"}
132 	,{0x01, "Primary DOS with 12 bit FAT"}
133 	,{0x02, "XENIX / file system"}
134 	,{0x03, "XENIX /usr file system"}
135 	,{0x04, "Primary DOS with 16 bit FAT (< 32MB)"}
136 	,{0x05, "Extended DOS"}
137 	,{0x06, "Primary 'big' DOS (>= 32MB)"}
138 	,{0x07, "OS/2 HPFS, NTFS, QNX-2 (16 bit) or Advanced UNIX"}
139 	,{0x08, "AIX file system or SplitDrive"}
140 	,{0x09, "AIX boot partition or Coherent"}
141 	,{0x0A, "OS/2 Boot Manager, OPUS or Coherent swap"}
142 	,{0x0B, "DOS or Windows 95 with 32 bit FAT"}
143 	,{0x0C, "DOS or Windows 95 with 32 bit FAT (LBA)"}
144 	,{0x0E, "Primary 'big' DOS (>= 32MB, LBA)"}
145 	,{0x0F, "Extended DOS (LBA)"}
146 	,{0x10, "OPUS"}
147 	,{0x11, "OS/2 BM: hidden DOS with 12-bit FAT"}
148 	,{0x12, "Compaq diagnostics"}
149 	,{0x14, "OS/2 BM: hidden DOS with 16-bit FAT (< 32MB)"}
150 	,{0x16, "OS/2 BM: hidden DOS with 16-bit FAT (>= 32MB)"}
151 	,{0x17, "OS/2 BM: hidden IFS (e.g. HPFS)"}
152 	,{0x18, "AST Windows swapfile"}
153 	,{0x24, "NEC DOS"}
154 	,{0x3C, "PartitionMagic recovery"}
155 	,{0x39, "plan9"}
156 	,{0x40, "VENIX 286"}
157 	,{0x41, "Linux/MINIX (sharing disk with DRDOS)"}
158 	,{0x42, "SFS or Linux swap (sharing disk with DRDOS)"}
159 	,{0x43, "Linux native (sharing disk with DRDOS)"}
160 	,{0x4D, "QNX 4.2 Primary"}
161 	,{0x4E, "QNX 4.2 Secondary"}
162 	,{0x4F, "QNX 4.2 Tertiary"}
163 	,{0x50, "DM (disk manager)"}
164 	,{0x51, "DM6 Aux1 (or Novell)"}
165 	,{0x52, "CP/M or Microport SysV/AT"}
166 	,{0x53, "DM6 Aux3"}
167 	,{0x54, "DM6"}
168 	,{0x55, "EZ-Drive (disk manager)"}
169 	,{0x56, "Golden Bow (disk manager)"}
170 	,{0x5c, "Priam Edisk (disk manager)"} /* according to S. Widlake */
171 	,{0x61, "SpeedStor"}
172 	,{0x63, "System V/386 (such as ISC UNIX), GNU HURD or Mach"}
173 	,{0x64, "Novell Netware/286 2.xx"}
174 	,{0x65, "Novell Netware/386 3.xx"}
175 	,{0x70, "DiskSecure Multi-Boot"}
176 	,{0x75, "PCIX"}
177 	,{0x77, "QNX4.x"}
178 	,{0x78, "QNX4.x 2nd part"}
179 	,{0x79, "QNX4.x 3rd part"}
180 	,{0x80, "Minix until 1.4a"}
181 	,{0x81, "Minix since 1.4b, early Linux partition or Mitac disk manager"}
182 	,{0x82, "Linux swap or Solaris x86"}
183 	,{0x83, "Linux native"}
184 	,{0x84, "OS/2 hidden C: drive"}
185 	,{0x85, "Linux extended"}
186 	,{0x86, "NTFS volume set??"}
187 	,{0x87, "NTFS volume set??"}
188 	,{0x93, "Amoeba file system"}
189 	,{0x94, "Amoeba bad block table"}
190 	,{0x9F, "BSD/OS"}
191 	,{0xA0, "Suspend to Disk"}
192 	,{0xA5, "FreeBSD/NetBSD/386BSD"}
193 	,{0xA6, "OpenBSD"}
194 	,{0xA7, "NeXTSTEP"}
195 	,{0xA9, "NetBSD"}
196 	,{0xAC, "IBM JFS"}
197 	,{0xAF, "HFS+"}
198 	,{0xB7, "BSDI BSD/386 file system"}
199 	,{0xB8, "BSDI BSD/386 swap"}
200 	,{0xBE, "Solaris x86 boot"}
201 	,{0xBF, "Solaris x86 (new)"}
202 	,{0xC1, "DRDOS/sec with 12-bit FAT"}
203 	,{0xC4, "DRDOS/sec with 16-bit FAT (< 32MB)"}
204 	,{0xC6, "DRDOS/sec with 16-bit FAT (>= 32MB)"}
205 	,{0xC7, "Syrinx"}
206 	,{0xDB, "CP/M, Concurrent CP/M, Concurrent DOS or CTOS"}
207 	,{0xE1, "DOS access or SpeedStor with 12-bit FAT extended partition"}
208 	,{0xE3, "DOS R/O or SpeedStor"}
209 	,{0xE4, "SpeedStor with 16-bit FAT extended partition < 1024 cyl."}
210 	,{0xEB, "BeOS file system"}
211 	,{0xEE, "EFI GPT"}
212 	,{0xEF, "EFI System Partition"}
213 	,{0xF1, "SpeedStor"}
214 	,{0xF2, "DOS 3.3+ Secondary"}
215 	,{0xF4, "SpeedStor large partition"}
216 	,{0xFE, "SpeedStor >1024 cyl. or LANstep"}
217 	,{0xFF, "Xenix bad blocks table"}
218 };
219 
220 static void print_s0(int which);
221 static void print_part(int i);
222 static void init_sector0(unsigned long start);
223 static void init_boot(void);
224 static void change_part(int i);
225 static void print_params(void);
226 static void change_active(int which);
227 static void change_code(void);
228 static void get_params_to_use(void);
229 static char *get_rootdisk(void);
230 static void dos(struct dos_partition *partp);
231 static int open_disk(int flag);
232 static ssize_t read_disk(off_t sector, void *buf);
233 static int write_disk(off_t sector, void *buf);
234 static int get_params(void);
235 static int read_s0(void);
236 static int write_s0(void);
237 static int ok(const char *str);
238 static int decimal(const char *str, int *num, int deflt);
239 static const char *get_type(int type);
240 static int read_config(char *config_file);
241 static void reset_boot(void);
242 static int sanitize_partition(struct dos_partition *);
243 static void usage(void);
244 
245 int
246 main(int argc, char *argv[])
247 {
248 	struct	stat sb;
249 	int	c, i;
250 	int	partition = -1;
251 	struct	dos_partition *partp;
252 
253 	while ((c = getopt(argc, argv, "BIab:f:ipqstuv1234")) != -1)
254 		switch (c) {
255 		case 'B':
256 			B_flag = 1;
257 			break;
258 		case 'I':
259 			I_flag = 1;
260 			break;
261 		case 'a':
262 			a_flag = 1;
263 			break;
264 		case 'b':
265 			b_flag = optarg;
266 			break;
267 		case 'f':
268 			f_flag = optarg;
269 			break;
270 		case 'i':
271 			i_flag = 1;
272 			break;
273 		case 'p':
274 			print_config_flag = 1;
275 			break;
276 		case 'q':
277 			q_flag = 1;
278 			break;
279 		case 's':
280 			s_flag = 1;
281 			break;
282 		case 't':
283 			t_flag = 1;
284 			break;
285 		case 'u':
286 			u_flag = 1;
287 			break;
288 		case 'v':
289 			v_flag = 1;
290 			break;
291 		case '1':
292 		case '2':
293 		case '3':
294 		case '4':
295 			partition = c - '0';
296 			break;
297 		default:
298 			usage();
299 		}
300 	if (f_flag || i_flag)
301 		u_flag = 1;
302 	if (t_flag)
303 		v_flag = 1;
304 	argc -= optind;
305 	argv += optind;
306 
307 	if (argc == 0) {
308 		disk = get_rootdisk();
309 	} else {
310 		if (stat(argv[0], &sb) == 0) {
311 			/* OK, full pathname given */
312 			disk = argv[0];
313 		} else if (errno == ENOENT && argv[0][0] != '/') {
314 			/* Try prepending "/dev" */
315 			asprintf(&disk, "%s%s", _PATH_DEV, argv[0]);
316 			if (disk == NULL)
317 				errx(1, "out of memory");
318 		} else {
319 			/* other stat error, let it fail below */
320 			disk = argv[0];
321 		}
322 	}
323 	if (open_disk(u_flag) < 0)
324 		err(1, "cannot open disk %s", disk);
325 
326 	/* (abu)use mboot.bootinst to probe for the sector size */
327 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
328 		err(1, "cannot allocate buffer to determine disk sector size");
329 	if (read_disk(0, mboot.bootinst) == -1)
330 		errx(1, "could not detect sector size");
331 	free(mboot.bootinst);
332 	mboot.bootinst = NULL;
333 
334 	if (print_config_flag) {
335 		if (read_s0())
336 			err(1, "read_s0");
337 
338 		printf("# %s\n", disk);
339 		printf("g c%d h%d s%d\n", dos_cyls, dos_heads, dos_sectors);
340 
341 		for (i = 0; i < NDOSPART; i++) {
342 			partp = ((struct dos_partition *)&mboot.parts) + i;
343 
344 			if (partp->dp_start == 0 && partp->dp_size == 0)
345 				continue;
346 
347 			printf("p %d 0x%02x %lu %lu\n", i + 1, partp->dp_typ,
348 			    (u_long)partp->dp_start, (u_long)partp->dp_size);
349 
350 			/* Fill flags for the partition. */
351 			if (partp->dp_flag & 0x80)
352 				printf("a %d\n", i + 1);
353 		}
354 		exit(0);
355 	}
356 	if (s_flag) {
357 		if (read_s0())
358 			err(1, "read_s0");
359 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
360 		    dos_sectors);
361 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
362 		for (i = 0; i < NDOSPART; i++) {
363 			partp = ((struct dos_partition *) &mboot.parts) + i;
364 			if (partp->dp_start == 0 && partp->dp_size == 0)
365 				continue;
366 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", i + 1,
367 			    (u_long) partp->dp_start,
368 			    (u_long) partp->dp_size, partp->dp_typ,
369 			    partp->dp_flag);
370 		}
371 		exit(0);
372 	}
373 
374 	printf("******* Working on device %s *******\n",disk);
375 
376 	if (I_flag) {
377 		read_s0();
378 		reset_boot();
379 		partp = (struct dos_partition *) (&mboot.parts[0]);
380 		partp->dp_typ = DOSPTYP_386BSD;
381 		partp->dp_flag = ACTIVE;
382 		partp->dp_start = dos_sectors;
383 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs -
384 		    dos_sectors;
385 		dos(partp);
386 		if (v_flag)
387 			print_s0(-1);
388 		if (!t_flag)
389 			write_s0();
390 		exit(0);
391 	}
392 	if (f_flag) {
393 	    if (read_s0() || i_flag)
394 		reset_boot();
395 	    if (!read_config(f_flag))
396 		exit(1);
397 	    if (v_flag)
398 		print_s0(-1);
399 	    if (!t_flag)
400 		write_s0();
401 	} else {
402 	    if(u_flag)
403 		get_params_to_use();
404 	    else
405 		print_params();
406 
407 	    if (read_s0())
408 		init_sector0(dos_sectors);
409 
410 	    printf("Media sector size is %d\n", secsize);
411 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
412 	    printf("Information from DOS bootblock is:\n");
413 	    if (partition == -1)
414 		for (i = 1; i <= NDOSPART; i++)
415 		    change_part(i);
416 	    else
417 		change_part(partition);
418 
419 	    if (u_flag || a_flag)
420 		change_active(partition);
421 
422 	    if (B_flag)
423 		change_code();
424 
425 	    if (u_flag || a_flag || B_flag) {
426 		if (!t_flag) {
427 		    printf("\nWe haven't changed the partition table yet.  ");
428 		    printf("This is your last chance.\n");
429 		}
430 		print_s0(-1);
431 		if (!t_flag) {
432 		    if (ok("Should we write new partition table?"))
433 			write_s0();
434 		} else {
435 		    printf("\n-t flag specified -- partition table not written.\n");
436 		}
437 	    }
438 	}
439 
440 	exit(0);
441 }
442 
443 static void
444 usage()
445 {
446 	fprintf(stderr, "%s%s",
447 		"usage: fdisk [-BIaipqstu] [-b bootcode] [-1234] [disk]\n",
448  		"       fdisk -f configfile [-itv] [disk]\n");
449         exit(1);
450 }
451 
452 static void
453 print_s0(int which)
454 {
455 	int	i;
456 
457 	print_params();
458 	printf("Information from DOS bootblock is:\n");
459 	if (which == -1)
460 		for (i = 1; i <= NDOSPART; i++)
461 			printf("%d: ", i), print_part(i);
462 	else
463 		print_part(which);
464 }
465 
466 static struct dos_partition mtpart;
467 
468 static void
469 print_part(int i)
470 {
471 	struct	  dos_partition *partp;
472 	u_int64_t part_mb;
473 
474 	partp = ((struct dos_partition *) &mboot.parts) + i - 1;
475 
476 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
477 		printf("<UNUSED>\n");
478 		return;
479 	}
480 	/*
481 	 * Be careful not to overflow.
482 	 */
483 	part_mb = partp->dp_size;
484 	part_mb *= secsize;
485 	part_mb /= (1024 * 1024);
486 	printf("sysid %d (%#04x),(%s)\n", partp->dp_typ, partp->dp_typ,
487 	    get_type(partp->dp_typ));
488 	printf("    start %lu, size %lu (%ju Meg), flag %x%s\n",
489 		(u_long)partp->dp_start,
490 		(u_long)partp->dp_size,
491 		(uintmax_t)part_mb,
492 		partp->dp_flag,
493 		partp->dp_flag == ACTIVE ? " (active)" : "");
494 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
495 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
496 		,partp->dp_shd
497 		,DPSECT(partp->dp_ssect)
498 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
499 		,partp->dp_ehd
500 		,DPSECT(partp->dp_esect));
501 }
502 
503 
504 static void
505 init_boot(void)
506 {
507 #ifndef __ia64__
508 	const char *fname;
509 	int fdesc, n;
510 	struct stat sb;
511 
512 	fname = b_flag ? b_flag : "/boot/mbr";
513 	if ((fdesc = open(fname, O_RDONLY)) == -1 ||
514 	    fstat(fdesc, &sb) == -1)
515 		err(1, "%s", fname);
516 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
517 		errx(1, "%s: length must be a multiple of sector size", fname);
518 	if (mboot.bootinst != NULL)
519 		free(mboot.bootinst);
520 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
521 		errx(1, "%s: unable to allocate read buffer", fname);
522 	if ((n = read(fdesc, mboot.bootinst, mboot.bootinst_size)) == -1 ||
523 	    close(fdesc))
524 		err(1, "%s", fname);
525 	if (n != mboot.bootinst_size)
526 		errx(1, "%s: short read", fname);
527 #else
528 	if (mboot.bootinst != NULL)
529 		free(mboot.bootinst);
530 	mboot.bootinst_size = secsize;
531 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL)
532 		errx(1, "unable to allocate boot block buffer");
533 	memset(mboot.bootinst, 0, mboot.bootinst_size);
534 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
535 #endif
536 }
537 
538 
539 static void
540 init_sector0(unsigned long start)
541 {
542 	struct dos_partition *partp = (struct dos_partition *) (&mboot.parts[0]);
543 
544 	init_boot();
545 
546 	partp->dp_typ = DOSPTYP_386BSD;
547 	partp->dp_flag = ACTIVE;
548 	start = ((start + dos_sectors - 1) / dos_sectors) * dos_sectors;
549 	if(start == 0)
550 		start = dos_sectors;
551 	partp->dp_start = start;
552 	partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
553 
554 	dos(partp);
555 }
556 
557 static void
558 change_part(int i)
559 {
560 	struct dos_partition *partp = ((struct dos_partition *) &mboot.parts) + i - 1;
561 
562     printf("The data for partition %d is:\n", i);
563     print_part(i);
564 
565     if (u_flag && ok("Do you want to change it?")) {
566 	int tmp;
567 
568 	if (i_flag) {
569 		bzero((char *)partp, sizeof (struct dos_partition));
570 		if (i == 1) {
571 			init_sector0(1);
572 			printf("\nThe static data for the slice 1 has been reinitialized to:\n");
573 			print_part(i);
574 		}
575 	}
576 
577 	do {
578 		Decimal("sysid (165=FreeBSD)", partp->dp_typ, tmp);
579 		Decimal("start", partp->dp_start, tmp);
580 		Decimal("size", partp->dp_size, tmp);
581 		if (!sanitize_partition(partp)) {
582 			warnx("ERROR: failed to adjust; setting sysid to 0");
583 			partp->dp_typ = 0;
584 		}
585 
586 		if (ok("Explicitly specify beg/end address ?"))
587 		{
588 			int	tsec,tcyl,thd;
589 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
590 			thd = partp->dp_shd;
591 			tsec = DPSECT(partp->dp_ssect);
592 			Decimal("beginning cylinder", tcyl, tmp);
593 			Decimal("beginning head", thd, tmp);
594 			Decimal("beginning sector", tsec, tmp);
595 			partp->dp_scyl = DOSCYL(tcyl);
596 			partp->dp_ssect = DOSSECT(tsec,tcyl);
597 			partp->dp_shd = thd;
598 
599 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
600 			thd = partp->dp_ehd;
601 			tsec = DPSECT(partp->dp_esect);
602 			Decimal("ending cylinder", tcyl, tmp);
603 			Decimal("ending head", thd, tmp);
604 			Decimal("ending sector", tsec, tmp);
605 			partp->dp_ecyl = DOSCYL(tcyl);
606 			partp->dp_esect = DOSSECT(tsec,tcyl);
607 			partp->dp_ehd = thd;
608 		} else
609 			dos(partp);
610 
611 		print_part(i);
612 	} while (!ok("Are we happy with this entry?"));
613     }
614 }
615 
616 static void
617 print_params()
618 {
619 	printf("parameters extracted from in-core disklabel are:\n");
620 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
621 			,cyls,heads,sectors,cylsecs);
622 	if (dos_cyls > 1023 || dos_heads > 255 || dos_sectors > 63)
623 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
624 	printf("parameters to be used for BIOS calculations are:\n");
625 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
626 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
627 }
628 
629 static void
630 change_active(int which)
631 {
632 	struct dos_partition *partp = &mboot.parts[0];
633 	int active, i, new, tmp;
634 
635 	active = -1;
636 	for (i = 0; i < NDOSPART; i++) {
637 		if ((partp[i].dp_flag & ACTIVE) == 0)
638 			continue;
639 		printf("Partition %d is marked active\n", i + 1);
640 		if (active == -1)
641 			active = i + 1;
642 	}
643 	if (a_flag && which != -1)
644 		active = which;
645 	else if (active == -1)
646 		active = 1;
647 
648 	if (!ok("Do you want to change the active partition?"))
649 		return;
650 setactive:
651 	do {
652 		new = active;
653 		Decimal("active partition", new, tmp);
654 		if (new < 1 || new > 4) {
655 			printf("Active partition number must be in range 1-4."
656 					"  Try again.\n");
657 			goto setactive;
658 		}
659 		active = new;
660 	} while (!ok("Are you happy with this choice"));
661 	for (i = 0; i < NDOSPART; i++)
662 		partp[i].dp_flag = 0;
663 	if (active > 0 && active <= NDOSPART)
664 		partp[active-1].dp_flag = ACTIVE;
665 }
666 
667 static void
668 change_code()
669 {
670 	if (ok("Do you want to change the boot code?"))
671 		init_boot();
672 }
673 
674 void
675 get_params_to_use()
676 {
677 	int	tmp;
678 	print_params();
679 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
680 	{
681 		do
682 		{
683 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp);
684 			Decimal("BIOS's idea of #heads", dos_heads, tmp);
685 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp);
686 			dos_cylsecs = dos_heads * dos_sectors;
687 			print_params();
688 		}
689 		while(!ok("Are you happy with this choice"));
690 	}
691 }
692 
693 
694 /***********************************************\
695 * Change real numbers into strange dos numbers	*
696 \***********************************************/
697 static void
698 dos(struct dos_partition *partp)
699 {
700 	int cy, sec;
701 	u_int32_t end;
702 
703 	if (partp->dp_typ == 0 && partp->dp_start == 0 && partp->dp_size == 0) {
704 		memcpy(partp, &mtpart, sizeof(*partp));
705 		return;
706 	}
707 
708 	/* Start c/h/s. */
709 	partp->dp_shd = partp->dp_start % dos_cylsecs / dos_sectors;
710 	cy = partp->dp_start / dos_cylsecs;
711 	sec = partp->dp_start % dos_sectors + 1;
712 	partp->dp_scyl = DOSCYL(cy);
713 	partp->dp_ssect = DOSSECT(sec, cy);
714 
715 	/* End c/h/s. */
716 	end = partp->dp_start + partp->dp_size - 1;
717 	partp->dp_ehd = end % dos_cylsecs / dos_sectors;
718 	cy = end / dos_cylsecs;
719 	sec = end % dos_sectors + 1;
720 	partp->dp_ecyl = DOSCYL(cy);
721 	partp->dp_esect = DOSSECT(sec, cy);
722 }
723 
724 static int
725 open_disk(int flag)
726 {
727 	struct stat 	st;
728 	int rwmode;
729 
730 	if (stat(disk, &st) == -1) {
731 		if (errno == ENOENT)
732 			return -2;
733 		warnx("can't get file status of %s", disk);
734 		return -1;
735 	}
736 	if ( !(st.st_mode & S_IFCHR) )
737 		warnx("device %s is not character special", disk);
738 	rwmode = a_flag || I_flag || B_flag || flag ? O_RDWR : O_RDONLY;
739 	fd = open(disk, rwmode);
740 	if (fd == -1 && errno == EPERM && rwmode == O_RDWR)
741 		fd = open(disk, O_RDONLY);
742 	if (fd == -1 && errno == ENXIO)
743 		return -2;
744 	if (fd == -1) {
745 		warnx("can't open device %s", disk);
746 		return -1;
747 	}
748 	if (get_params() == -1) {
749 		warnx("can't get disk parameters on %s", disk);
750 		return -1;
751 	}
752 	return fd;
753 }
754 
755 static ssize_t
756 read_disk(off_t sector, void *buf)
757 {
758 
759 	lseek(fd, (sector * 512), 0);
760 	if (secsize == 0)
761 		for (secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE;
762 		     secsize *= 2) {
763 			/* try the read */
764 			int size = read(fd, buf, secsize);
765 			if (size == secsize)
766 				/* it worked so return */
767 				return secsize;
768 		}
769 	else
770 		return read(fd, buf, secsize);
771 
772 	/* we failed to read at any of the sizes */
773 	return -1;
774 }
775 
776 static int
777 write_disk(off_t sector, void *buf)
778 {
779 	int error;
780 	struct gctl_req *grq;
781 	const char *q;
782 	char fbuf[BUFSIZ];
783 	int i, fdw;
784 
785 	grq = gctl_get_handle();
786 	gctl_ro_param(grq, "verb", -1, "write MBR");
787 	gctl_ro_param(grq, "class", -1, "MBR");
788 	q = strrchr(disk, '/');
789 	if (q == NULL)
790 		q = disk;
791 	else
792 		q++;
793 	gctl_ro_param(grq, "geom", -1, q);
794 	gctl_ro_param(grq, "data", secsize, buf);
795 	q = gctl_issue(grq);
796 	if (q == NULL) {
797 		gctl_free(grq);
798 		return(0);
799 	}
800 	if (!q_flag)	/* GEOM errors are benign, not all devices supported */
801 		warnx("%s", q);
802 	gctl_free(grq);
803 
804 	error = pwrite(fd, buf, secsize, (sector * 512));
805 	if (error == secsize)
806 		return (0);
807 
808 	for (i = 1; i < 5; i++) {
809 		sprintf(fbuf, "%ss%d", disk, i);
810 		fdw = open(fbuf, O_RDWR, 0);
811 		if (fdw < 0)
812 			continue;
813 		error = ioctl(fdw, DIOCSMBR, buf);
814 		close(fdw);
815 		if (error == 0)
816 			return (0);
817 	}
818 	warnx("Failed to write sector zero");
819 	return(EINVAL);
820 }
821 
822 static int
823 get_params()
824 {
825 	int error;
826 	u_int u;
827 	off_t o;
828 
829 	error = ioctl(fd, DIOCGFWSECTORS, &u);
830 	if (error == 0)
831 		sectors = dos_sectors = u;
832 	else
833 		sectors = dos_sectors = 63;
834 
835 	error = ioctl(fd, DIOCGFWHEADS, &u);
836 	if (error == 0)
837 		heads = dos_heads = u;
838 	else
839 		heads = dos_heads = 255;
840 
841 	dos_cylsecs = cylsecs = heads * sectors;
842 	disksecs = cyls * heads * sectors;
843 
844 	error = ioctl(fd, DIOCGSECTORSIZE, &u);
845 	if (error != 0 || u == 0)
846 		u = 512;
847 	else
848 		secsize = u;
849 
850 	error = ioctl(fd, DIOCGMEDIASIZE, &o);
851 	if (error == 0) {
852 		disksecs = o / u;
853 		cyls = dos_cyls = o / (u * dos_heads * dos_sectors);
854 	}
855 
856 	return (disksecs);
857 }
858 
859 
860 static int
861 read_s0()
862 {
863 	int i;
864 
865 	mboot.bootinst_size = secsize;
866 	if (mboot.bootinst != NULL)
867 		free(mboot.bootinst);
868 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
869 		warnx("unable to allocate buffer to read fdisk "
870 		      "partition table");
871 		return -1;
872 	}
873 	if (read_disk(0, mboot.bootinst) == -1) {
874 		warnx("can't read fdisk partition table");
875 		return -1;
876 	}
877 	if (le16dec(&mboot.bootinst[DOSMAGICOFFSET]) != DOSMAGIC) {
878 		warnx("invalid fdisk partition table found");
879 		/* So should we initialize things */
880 		return -1;
881 	}
882 	for (i = 0; i < NDOSPART; i++)
883 		dos_partition_dec(
884 		    &mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
885 		    &mboot.parts[i]);
886 	return 0;
887 }
888 
889 static int
890 write_s0()
891 {
892 	int	sector, i;
893 
894 	if (iotest) {
895 		print_s0(-1);
896 		return 0;
897 	}
898 	for(i = 0; i < NDOSPART; i++)
899 		dos_partition_enc(&mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
900 		    &mboot.parts[i]);
901 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
902 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
903 		if (write_disk(sector,
904 			       &mboot.bootinst[sector * secsize]) == -1) {
905 			warn("can't write fdisk partition table");
906 			return -1;
907 		}
908 	return(0);
909 }
910 
911 
912 static int
913 ok(const char *str)
914 {
915 	printf("%s [n] ", str);
916 	fflush(stdout);
917 	if (fgets(lbuf, LBUF, stdin) == NULL)
918 		exit(1);
919 	lbuf[strlen(lbuf)-1] = 0;
920 
921 	if (*lbuf &&
922 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
923 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
924 		return 1;
925 	else
926 		return 0;
927 }
928 
929 static int
930 decimal(const char *str, int *num, int deflt)
931 {
932 	int acc = 0, c;
933 	char *cp;
934 
935 	while (1) {
936 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
937 		fflush(stdout);
938 		if (fgets(lbuf, LBUF, stdin) == NULL)
939 			exit(1);
940 		lbuf[strlen(lbuf)-1] = 0;
941 
942 		if (!*lbuf)
943 			return 0;
944 
945 		cp = lbuf;
946 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
947 		if (!c)
948 			return 0;
949 		while ((c = *cp++)) {
950 			if (c <= '9' && c >= '0')
951 				acc = acc * 10 + c - '0';
952 			else
953 				break;
954 		}
955 		if (c == ' ' || c == '\t')
956 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
957 		if (!c) {
958 			*num = acc;
959 			return 1;
960 		} else
961 			printf("%s is an invalid decimal number.  Try again.\n",
962 				lbuf);
963 	}
964 
965 }
966 
967 static const char *
968 get_type(int type)
969 {
970 	int	numentries = (sizeof(part_types)/sizeof(struct part_type));
971 	int	counter = 0;
972 	struct	part_type *ptr = part_types;
973 
974 
975 	while(counter < numentries) {
976 		if(ptr->type == type)
977 			return(ptr->name);
978 		ptr++;
979 		counter++;
980 	}
981 	return("unknown");
982 }
983 
984 
985 static void
986 parse_config_line(char *line, CMD *command)
987 {
988     char	*cp, *end;
989 
990     cp = line;
991     while (1) {
992 	memset(command, 0, sizeof(*command));
993 
994 	while (isspace(*cp)) ++cp;
995 	if (*cp == '\0' || *cp == '#')
996 	    break;
997 	command->cmd = *cp++;
998 
999 	/*
1000 	 * Parse args
1001 	 */
1002 	    while (1) {
1003 	    while (isspace(*cp)) ++cp;
1004 	    if (*cp == '#')
1005 		break;		/* found comment */
1006 	    if (isalpha(*cp))
1007 		command->args[command->n_args].argtype = *cp++;
1008 	    if (!isdigit(*cp))
1009 		break;		/* assume end of line */
1010 	    end = NULL;
1011 	    command->args[command->n_args].arg_val = strtol(cp, &end, 0);
1012 	    if (cp == end)
1013 		break;		/* couldn't parse number */
1014 	    cp = end;
1015 	    command->n_args++;
1016 	}
1017 	break;
1018     }
1019 }
1020 
1021 
1022 static int
1023 process_geometry(CMD *command)
1024 {
1025     int		status = 1, i;
1026 
1027     while (1) {
1028 	geom_processed = 1;
1029 	    if (part_processed) {
1030 	    warnx(
1031 	"ERROR line %d: the geometry specification line must occur before\n\
1032     all partition specifications",
1033 		    current_line_number);
1034 	    status = 0;
1035 	    break;
1036 	}
1037 	    if (command->n_args != 3) {
1038 	    warnx("ERROR line %d: incorrect number of geometry args",
1039 		    current_line_number);
1040 	    status = 0;
1041 	    break;
1042 	}
1043 	    dos_cyls = 0;
1044 	    dos_heads = 0;
1045 	    dos_sectors = 0;
1046 	    for (i = 0; i < 3; ++i) {
1047 		    switch (command->args[i].argtype) {
1048 	    case 'c':
1049 		dos_cyls = command->args[i].arg_val;
1050 		break;
1051 	    case 'h':
1052 		dos_heads = command->args[i].arg_val;
1053 		break;
1054 	    case 's':
1055 		dos_sectors = command->args[i].arg_val;
1056 		break;
1057 	    default:
1058 		warnx(
1059 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1060 			current_line_number, command->args[i].argtype,
1061 			command->args[i].argtype);
1062 		status = 0;
1063 		break;
1064 	    }
1065 	}
1066 	if (status == 0)
1067 	    break;
1068 
1069 	dos_cylsecs = dos_heads * dos_sectors;
1070 
1071 	/*
1072 	 * Do sanity checks on parameter values
1073 	 */
1074 	    if (dos_cyls == 0) {
1075 	    warnx("ERROR line %d: number of cylinders not specified",
1076 		    current_line_number);
1077 	    status = 0;
1078 	}
1079 	    if (dos_cyls > 1024) {
1080 	    warnx(
1081 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1082     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1083     is dedicated to FreeBSD)",
1084 		    current_line_number, dos_cyls);
1085 	}
1086 
1087 	    if (dos_heads == 0) {
1088 	    warnx("ERROR line %d: number of heads not specified",
1089 		    current_line_number);
1090 	    status = 0;
1091 	    } else if (dos_heads > 256) {
1092 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1093 		    current_line_number);
1094 	    status = 0;
1095 	}
1096 
1097 	    if (dos_sectors == 0) {
1098 	    warnx("ERROR line %d: number of sectors not specified",
1099 		    current_line_number);
1100 	    status = 0;
1101 	    } else if (dos_sectors > 63) {
1102 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1103 		    current_line_number);
1104 	    status = 0;
1105 	}
1106 
1107 	break;
1108     }
1109     return (status);
1110 }
1111 
1112 
1113 static int
1114 process_partition(CMD *command)
1115 {
1116     int				status = 0, partition;
1117     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1118     u_int32_t			adj_size, max_end;
1119     struct dos_partition	*partp;
1120 
1121 	while (1) {
1122 	part_processed = 1;
1123 		if (command->n_args != 4) {
1124 	    warnx("ERROR line %d: incorrect number of partition args",
1125 		    current_line_number);
1126 	    break;
1127 	}
1128 	partition = command->args[0].arg_val;
1129 		if (partition < 1 || partition > 4) {
1130 	    warnx("ERROR line %d: invalid partition number %d",
1131 		    current_line_number, partition);
1132 	    break;
1133 	}
1134 	partp = ((struct dos_partition *) &mboot.parts) + partition - 1;
1135 	bzero((char *)partp, sizeof (struct dos_partition));
1136 	partp->dp_typ = command->args[1].arg_val;
1137 	partp->dp_start = command->args[2].arg_val;
1138 	partp->dp_size = command->args[3].arg_val;
1139 	max_end = partp->dp_start + partp->dp_size;
1140 
1141 		if (partp->dp_typ == 0) {
1142 	    /*
1143 	     * Get out, the partition is marked as unused.
1144 	     */
1145 	    /*
1146 	     * Insure that it's unused.
1147 	     */
1148 	    bzero((char *)partp, sizeof (struct dos_partition));
1149 	    status = 1;
1150 	    break;
1151 	}
1152 
1153 	/*
1154 	 * Adjust start upwards, if necessary, to fall on a head boundary.
1155 	 */
1156 		if (partp->dp_start % dos_sectors != 0) {
1157 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1158 	    if (max_end < dos_sectors ||
1159 			    prev_head_boundary > max_end - dos_sectors) {
1160 		/*
1161 		 * Can't go past end of partition
1162 		 */
1163 		warnx(
1164 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1165     a head boundary",
1166 			current_line_number, partition);
1167 		break;
1168 	    }
1169 	    warnx(
1170 	"WARNING: adjusting start offset of partition %d\n\
1171     from %u to %u, to fall on a head boundary",
1172 		    partition, (u_int)partp->dp_start,
1173 		    (u_int)(prev_head_boundary + dos_sectors));
1174 	    partp->dp_start = prev_head_boundary + dos_sectors;
1175 	}
1176 
1177 	/*
1178 	 * Adjust size downwards, if necessary, to fall on a cylinder
1179 	 * boundary.
1180 	 */
1181 	prev_cyl_boundary =
1182 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1183 	if (prev_cyl_boundary > partp->dp_start)
1184 	    adj_size = prev_cyl_boundary - partp->dp_start;
1185 		else {
1186 	    warnx(
1187 	"ERROR: could not adjust partition to start on a head boundary\n\
1188     and end on a cylinder boundary.");
1189 	    return (0);
1190 	}
1191 		if (adj_size != partp->dp_size) {
1192 	    warnx(
1193 	"WARNING: adjusting size of partition %d from %u to %u\n\
1194     to end on a cylinder boundary",
1195 		    partition, (u_int)partp->dp_size, (u_int)adj_size);
1196 	    partp->dp_size = adj_size;
1197 	}
1198 		if (partp->dp_size == 0) {
1199 	    warnx("ERROR line %d: size of partition %d is zero",
1200 		    current_line_number, partition);
1201 	    break;
1202 	}
1203 
1204 	dos(partp);
1205 	status = 1;
1206 	break;
1207     }
1208     return (status);
1209 }
1210 
1211 
1212 static int
1213 process_active(CMD *command)
1214 {
1215     int				status = 0, partition, i;
1216     struct dos_partition	*partp;
1217 
1218 	while (1) {
1219 	active_processed = 1;
1220 		if (command->n_args != 1) {
1221 	    warnx("ERROR line %d: incorrect number of active args",
1222 		    current_line_number);
1223 	    status = 0;
1224 	    break;
1225 	}
1226 	partition = command->args[0].arg_val;
1227 		if (partition < 1 || partition > 4) {
1228 	    warnx("ERROR line %d: invalid partition number %d",
1229 		    current_line_number, partition);
1230 	    break;
1231 	}
1232 	/*
1233 	 * Reset active partition
1234 	 */
1235 	partp = ((struct dos_partition *) &mboot.parts);
1236 	for (i = 0; i < NDOSPART; i++)
1237 	    partp[i].dp_flag = 0;
1238 	partp[partition-1].dp_flag = ACTIVE;
1239 
1240 	status = 1;
1241 	break;
1242     }
1243     return (status);
1244 }
1245 
1246 
1247 static int
1248 process_line(char *line)
1249 {
1250     CMD		command;
1251     int		status = 1;
1252 
1253 	while (1) {
1254 	parse_config_line(line, &command);
1255 		switch (command.cmd) {
1256 	case 0:
1257 	    /*
1258 	     * Comment or blank line
1259 	     */
1260 	    break;
1261 	case 'g':
1262 	    /*
1263 	     * Set geometry
1264 	     */
1265 	    status = process_geometry(&command);
1266 	    break;
1267 	case 'p':
1268 	    status = process_partition(&command);
1269 	    break;
1270 	case 'a':
1271 	    status = process_active(&command);
1272 	    break;
1273 	default:
1274 	    status = 0;
1275 	    break;
1276 	}
1277 	break;
1278     }
1279     return (status);
1280 }
1281 
1282 
1283 static int
1284 read_config(char *config_file)
1285 {
1286     FILE	*fp = NULL;
1287     int		status = 1;
1288     char	buf[1010];
1289 
1290 	while (1) {
1291 		if (strcmp(config_file, "-") != 0) {
1292 	    /*
1293 	     * We're not reading from stdin
1294 	     */
1295 			if ((fp = fopen(config_file, "r")) == NULL) {
1296 		status = 0;
1297 		break;
1298 	    }
1299 		} else {
1300 	    fp = stdin;
1301 	}
1302 	current_line_number = 0;
1303 		while (!feof(fp)) {
1304 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1305 		break;
1306 	    ++current_line_number;
1307 	    status = process_line(buf);
1308 	    if (status == 0)
1309 		break;
1310 	    }
1311 	break;
1312     }
1313 	if (fp) {
1314 	/*
1315 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1316 	 */
1317 	fclose(fp);
1318     }
1319     return (status);
1320 }
1321 
1322 
1323 static void
1324 reset_boot(void)
1325 {
1326     int				i;
1327     struct dos_partition	*partp;
1328 
1329     init_boot();
1330 	for (i = 0; i < 4; ++i) {
1331 	partp = ((struct dos_partition *) &mboot.parts) + i;
1332 	bzero((char *)partp, sizeof (struct dos_partition));
1333     }
1334 }
1335 
1336 static int
1337 sanitize_partition(struct dos_partition *partp)
1338 {
1339     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1340     u_int32_t			max_end, size, start;
1341 
1342     start = partp->dp_start;
1343     size = partp->dp_size;
1344     max_end = start + size;
1345     /* Only allow a zero size if the partition is being marked unused. */
1346     if (size == 0) {
1347 	if (start == 0 && partp->dp_typ == 0)
1348 	    return (1);
1349 	warnx("ERROR: size of partition is zero");
1350 	return (0);
1351     }
1352     /* Return if no adjustment is necessary. */
1353     if (start % dos_sectors == 0 && (start + size) % dos_sectors == 0)
1354 	return (1);
1355 
1356     if (start == 0) {
1357 	    warnx("WARNING: partition overlaps with partition table");
1358 	    if (ok("Correct this automatically?"))
1359 		    start = dos_sectors;
1360     }
1361     if (start % dos_sectors != 0)
1362 	warnx("WARNING: partition does not start on a head boundary");
1363     if ((start  +size) % dos_sectors != 0)
1364 	warnx("WARNING: partition does not end on a cylinder boundary");
1365     warnx("WARNING: this may confuse the BIOS or some operating systems");
1366     if (!ok("Correct this automatically?"))
1367 	return (1);
1368 
1369     /*
1370      * Adjust start upwards, if necessary, to fall on a head boundary.
1371      */
1372     if (start % dos_sectors != 0) {
1373 	prev_head_boundary = start / dos_sectors * dos_sectors;
1374 	if (max_end < dos_sectors ||
1375 	    prev_head_boundary >= max_end - dos_sectors) {
1376 	    /*
1377 	     * Can't go past end of partition
1378 	     */
1379 	    warnx(
1380     "ERROR: unable to adjust start of partition to fall on a head boundary");
1381 	    return (0);
1382         }
1383 	start = prev_head_boundary + dos_sectors;
1384     }
1385 
1386     /*
1387      * Adjust size downwards, if necessary, to fall on a cylinder
1388      * boundary.
1389      */
1390     prev_cyl_boundary = ((start + size) / dos_cylsecs) * dos_cylsecs;
1391     if (prev_cyl_boundary > start)
1392 	size = prev_cyl_boundary - start;
1393     else {
1394 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1395     and end on a cylinder boundary.");
1396 	return (0);
1397     }
1398 
1399     /* Finally, commit any changes to partp and return. */
1400     if (start != partp->dp_start) {
1401 	warnx("WARNING: adjusting start offset of partition to %u",
1402 	    (u_int)start);
1403 	partp->dp_start = start;
1404     }
1405     if (size != partp->dp_size) {
1406 	warnx("WARNING: adjusting size of partition to %u", (u_int)size);
1407 	partp->dp_size = size;
1408     }
1409 
1410     return (1);
1411 }
1412 
1413 /*
1414  * Try figuring out the root device's canonical disk name.
1415  * The following choices are considered:
1416  *   /dev/ad0s1a     => /dev/ad0
1417  *   /dev/da0a       => /dev/da0
1418  *   /dev/vinum/root => /dev/vinum/root
1419  */
1420 static char *
1421 get_rootdisk(void)
1422 {
1423 	struct statfs rootfs;
1424 	regex_t re;
1425 #define NMATCHES 2
1426 	regmatch_t rm[NMATCHES];
1427 	char *s;
1428 	int rv;
1429 
1430 	if (statfs("/", &rootfs) == -1)
1431 		err(1, "statfs(\"/\")");
1432 
1433 	if ((rv = regcomp(&re, "^(/dev/[a-z/]+[0-9]+)([sp][0-9]+)?[a-h]?$",
1434 		    REG_EXTENDED)) != 0)
1435 		errx(1, "regcomp() failed (%d)", rv);
1436 	if ((rv = regexec(&re, rootfs.f_mntfromname, NMATCHES, rm, 0)) != 0)
1437 		errx(1,
1438 "mounted root fs resource doesn't match expectations (regexec returned %d)",
1439 		    rv);
1440 	if ((s = malloc(rm[1].rm_eo - rm[1].rm_so + 1)) == NULL)
1441 		errx(1, "out of memory");
1442 	memcpy(s, rootfs.f_mntfromname + rm[1].rm_so,
1443 	    rm[1].rm_eo - rm[1].rm_so);
1444 	s[rm[1].rm_eo - rm[1].rm_so] = 0;
1445 
1446 	return s;
1447 }
1448