xref: /freebsd/sbin/fdisk/fdisk.c (revision c74c7b73a005e689b922dfcfe5b94804669b595b)
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 *bootinst;  /* boot code */
78 	off_t bootinst_size;
79 	struct	dos_partition parts[NDOSPART];
80 };
81 
82 static struct mboot mboot;
83 static int fd;
84 
85 #define ACTIVE 0x80
86 
87 static uint dos_cyls;
88 static uint dos_heads;
89 static uint dos_sectors;
90 static uint dos_cylsecs;
91 
92 #define DOSSECT(s,c) ((s & 0x3f) | ((c >> 2) & 0xc0))
93 #define DOSCYL(c)	(c & 0xff)
94 
95 #define MAX_ARGS	10
96 
97 static int	current_line_number;
98 
99 static int	geom_processed = 0;
100 static int	part_processed = 0;
101 static int	active_processed = 0;
102 
103 typedef struct cmd {
104     char		cmd;
105     int			n_args;
106     struct arg {
107 	char	argtype;
108 	int	arg_val;
109     }			args[MAX_ARGS];
110 } CMD;
111 
112 static int B_flag  = 0;		/* replace boot code */
113 static int I_flag  = 0;		/* use entire disk for FreeBSD */
114 static int a_flag  = 0;		/* set active partition */
115 static char *b_flag = NULL;	/* path to boot code */
116 static int i_flag  = 0;		/* replace partition data */
117 static int q_flag  = 0;		/* Be quiet */
118 static int u_flag  = 0;		/* update partition data */
119 static int s_flag  = 0;		/* Print a summary and exit */
120 static int t_flag  = 0;		/* test only */
121 static char *f_flag = NULL;	/* Read config info from file */
122 static int v_flag  = 0;		/* Be verbose */
123 static int print_config_flag = 0;
124 
125 static struct part_type
126 {
127 	unsigned char type;
128 	const char *name;
129 } part_types[] = {
130 	 {0x00, "unused"}
131 	,{0x01, "Primary DOS with 12 bit FAT"}
132 	,{0x02, "XENIX / file system"}
133 	,{0x03, "XENIX /usr file system"}
134 	,{0x04, "Primary DOS with 16 bit FAT (< 32MB)"}
135 	,{0x05, "Extended DOS"}
136 	,{0x06, "Primary 'big' DOS (>= 32MB)"}
137 	,{0x07, "OS/2 HPFS, NTFS, QNX-2 (16 bit) or Advanced UNIX"}
138 	,{0x08, "AIX file system or SplitDrive"}
139 	,{0x09, "AIX boot partition or Coherent"}
140 	,{0x0A, "OS/2 Boot Manager, OPUS or Coherent swap"}
141 	,{0x0B, "DOS or Windows 95 with 32 bit FAT"}
142 	,{0x0C, "DOS or Windows 95 with 32 bit FAT (LBA)"}
143 	,{0x0E, "Primary 'big' DOS (>= 32MB, LBA)"}
144 	,{0x0F, "Extended DOS (LBA)"}
145 	,{0x10, "OPUS"}
146 	,{0x11, "OS/2 BM: hidden DOS with 12-bit FAT"}
147 	,{0x12, "Compaq diagnostics"}
148 	,{0x14, "OS/2 BM: hidden DOS with 16-bit FAT (< 32MB)"}
149 	,{0x16, "OS/2 BM: hidden DOS with 16-bit FAT (>= 32MB)"}
150 	,{0x17, "OS/2 BM: hidden IFS (e.g. HPFS)"}
151 	,{0x18, "AST Windows swapfile"}
152 	,{0x24, "NEC DOS"}
153 	,{0x3C, "PartitionMagic recovery"}
154 	,{0x39, "plan9"}
155 	,{0x40, "VENIX 286"}
156 	,{0x41, "Linux/MINIX (sharing disk with DRDOS)"}
157 	,{0x42, "SFS or Linux swap (sharing disk with DRDOS)"}
158 	,{0x43, "Linux native (sharing disk with DRDOS)"}
159 	,{0x4D, "QNX 4.2 Primary"}
160 	,{0x4E, "QNX 4.2 Secondary"}
161 	,{0x4F, "QNX 4.2 Tertiary"}
162 	,{0x50, "DM (disk manager)"}
163 	,{0x51, "DM6 Aux1 (or Novell)"}
164 	,{0x52, "CP/M or Microport SysV/AT"}
165 	,{0x53, "DM6 Aux3"}
166 	,{0x54, "DM6"}
167 	,{0x55, "EZ-Drive (disk manager)"}
168 	,{0x56, "Golden Bow (disk manager)"}
169 	,{0x5c, "Priam Edisk (disk manager)"} /* according to S. Widlake */
170 	,{0x61, "SpeedStor"}
171 	,{0x63, "System V/386 (such as ISC UNIX), GNU HURD or Mach"}
172 	,{0x64, "Novell Netware/286 2.xx"}
173 	,{0x65, "Novell Netware/386 3.xx"}
174 	,{0x70, "DiskSecure Multi-Boot"}
175 	,{0x75, "PCIX"}
176 	,{0x77, "QNX4.x"}
177 	,{0x78, "QNX4.x 2nd part"}
178 	,{0x79, "QNX4.x 3rd part"}
179 	,{0x80, "Minix until 1.4a"}
180 	,{0x81, "Minix since 1.4b, early Linux partition or Mitac disk manager"}
181 	,{0x82, "Linux swap or Solaris x86"}
182 	,{0x83, "Linux native"}
183 	,{0x84, "OS/2 hidden C: drive"}
184 	,{0x85, "Linux extended"}
185 	,{0x86, "NTFS volume set??"}
186 	,{0x87, "NTFS volume set??"}
187 	,{0x93, "Amoeba file system"}
188 	,{0x94, "Amoeba bad block table"}
189 	,{0x9F, "BSD/OS"}
190 	,{0xA0, "Suspend to Disk"}
191 	,{0xA5, "FreeBSD/NetBSD/386BSD"}
192 	,{0xA6, "OpenBSD"}
193 	,{0xA7, "NeXTSTEP"}
194 	,{0xA9, "NetBSD"}
195 	,{0xAC, "IBM JFS"}
196 	,{0xAF, "HFS+"}
197 	,{0xB7, "BSDI BSD/386 file system"}
198 	,{0xB8, "BSDI BSD/386 swap"}
199 	,{0xBE, "Solaris x86 boot"}
200 	,{0xBF, "Solaris x86 (new)"}
201 	,{0xC1, "DRDOS/sec with 12-bit FAT"}
202 	,{0xC4, "DRDOS/sec with 16-bit FAT (< 32MB)"}
203 	,{0xC6, "DRDOS/sec with 16-bit FAT (>= 32MB)"}
204 	,{0xC7, "Syrinx"}
205 	,{0xDB, "CP/M, Concurrent CP/M, Concurrent DOS or CTOS"}
206 	,{0xE1, "DOS access or SpeedStor with 12-bit FAT extended partition"}
207 	,{0xE3, "DOS R/O or SpeedStor"}
208 	,{0xE4, "SpeedStor with 16-bit FAT extended partition < 1024 cyl."}
209 	,{0xEB, "BeOS file system"}
210 	,{0xEE, "EFI GPT"}
211 	,{0xEF, "EFI System Partition"}
212 	,{0xF1, "SpeedStor"}
213 	,{0xF2, "DOS 3.3+ Secondary"}
214 	,{0xF4, "SpeedStor large partition"}
215 	,{0xFE, "SpeedStor >1024 cyl. or LANstep"}
216 	,{0xFF, "Xenix bad blocks table"}
217 };
218 
219 static void print_s0(int which);
220 static void print_part(int i);
221 static void init_sector0(unsigned long start);
222 static void init_boot(void);
223 static void change_part(int i);
224 static void print_params(void);
225 static void change_active(int which);
226 static void change_code(void);
227 static void get_params_to_use(void);
228 static char *get_rootdisk(void);
229 static void dos(struct dos_partition *partp);
230 static int open_disk(int flag);
231 static ssize_t read_disk(off_t sector, void *buf);
232 static int write_disk(off_t sector, void *buf);
233 static int get_params(void);
234 static int read_s0(void);
235 static int write_s0(void);
236 static int ok(const char *str);
237 static int decimal(const char *str, int *num, int deflt);
238 static const char *get_type(int type);
239 static int read_config(char *config_file);
240 static void reset_boot(void);
241 static int sanitize_partition(struct dos_partition *);
242 static void usage(void);
243 
244 int
245 main(int argc, char *argv[])
246 {
247 	int	c, i;
248 	int	partition = -1;
249 	struct	dos_partition *partp;
250 
251 	while ((c = getopt(argc, argv, "BIab:f:ipqstuv1234")) != -1)
252 		switch (c) {
253 		case 'B':
254 			B_flag = 1;
255 			break;
256 		case 'I':
257 			I_flag = 1;
258 			break;
259 		case 'a':
260 			a_flag = 1;
261 			break;
262 		case 'b':
263 			b_flag = optarg;
264 			break;
265 		case 'f':
266 			f_flag = optarg;
267 			break;
268 		case 'i':
269 			i_flag = 1;
270 			break;
271 		case 'p':
272 			print_config_flag = 1;
273 			break;
274 		case 'q':
275 			q_flag = 1;
276 			break;
277 		case 's':
278 			s_flag = 1;
279 			break;
280 		case 't':
281 			t_flag = 1;
282 			break;
283 		case 'u':
284 			u_flag = 1;
285 			break;
286 		case 'v':
287 			v_flag = 1;
288 			break;
289 		case '1':
290 		case '2':
291 		case '3':
292 		case '4':
293 			partition = c - '0';
294 			break;
295 		default:
296 			usage();
297 		}
298 	if (f_flag || i_flag)
299 		u_flag = 1;
300 	if (t_flag)
301 		v_flag = 1;
302 	argc -= optind;
303 	argv += optind;
304 
305 	if (argc == 0) {
306 		disk = get_rootdisk();
307 	} else {
308 		disk = g_device_path(argv[0]);
309 		if (disk == NULL)
310 			err(1, "unable to get correct path for %s", argv[0]);
311 	}
312 	if (open_disk(u_flag) < 0)
313 		err(1, "cannot open disk %s", disk);
314 
315 	/* (abu)use mboot.bootinst to probe for the sector size */
316 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
317 		err(1, "cannot allocate buffer to determine disk sector size");
318 	if (read_disk(0, mboot.bootinst) == -1)
319 		errx(1, "could not detect sector size");
320 	free(mboot.bootinst);
321 	mboot.bootinst = NULL;
322 
323 	if (print_config_flag) {
324 		if (read_s0())
325 			err(1, "read_s0");
326 
327 		printf("# %s\n", disk);
328 		printf("g c%d h%d s%d\n", dos_cyls, dos_heads, dos_sectors);
329 
330 		for (i = 0; i < NDOSPART; i++) {
331 			partp = &mboot.parts[i];
332 
333 			if (partp->dp_start == 0 && partp->dp_size == 0)
334 				continue;
335 
336 			printf("p %d 0x%02x %lu %lu\n", i + 1, partp->dp_typ,
337 			    (u_long)partp->dp_start, (u_long)partp->dp_size);
338 
339 			/* Fill flags for the partition. */
340 			if (partp->dp_flag & 0x80)
341 				printf("a %d\n", i + 1);
342 		}
343 		exit(0);
344 	}
345 	if (s_flag) {
346 		if (read_s0())
347 			err(1, "read_s0");
348 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
349 		    dos_sectors);
350 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
351 		for (i = 0; i < NDOSPART; i++) {
352 			partp = &mboot.parts[i];
353 			if (partp->dp_start == 0 && partp->dp_size == 0)
354 				continue;
355 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", i + 1,
356 			    (u_long) partp->dp_start,
357 			    (u_long) partp->dp_size, partp->dp_typ,
358 			    partp->dp_flag);
359 		}
360 		exit(0);
361 	}
362 
363 	printf("******* Working on device %s *******\n",disk);
364 
365 	if (I_flag) {
366 		read_s0();
367 		reset_boot();
368 		partp = &mboot.parts[0];
369 		partp->dp_typ = DOSPTYP_386BSD;
370 		partp->dp_flag = ACTIVE;
371 		partp->dp_start = dos_sectors;
372 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs -
373 		    dos_sectors;
374 		dos(partp);
375 		if (v_flag)
376 			print_s0(-1);
377 		if (!t_flag)
378 			write_s0();
379 		exit(0);
380 	}
381 	if (f_flag) {
382 	    if (read_s0() || i_flag)
383 		reset_boot();
384 	    if (!read_config(f_flag))
385 		exit(1);
386 	    if (v_flag)
387 		print_s0(-1);
388 	    if (!t_flag)
389 		write_s0();
390 	} else {
391 	    if(u_flag)
392 		get_params_to_use();
393 	    else
394 		print_params();
395 
396 	    if (read_s0())
397 		init_sector0(dos_sectors);
398 
399 	    printf("Media sector size is %d\n", secsize);
400 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
401 	    printf("Information from DOS bootblock is:\n");
402 	    if (partition == -1)
403 		for (i = 1; i <= NDOSPART; i++)
404 		    change_part(i);
405 	    else
406 		change_part(partition);
407 
408 	    if (u_flag || a_flag)
409 		change_active(partition);
410 
411 	    if (B_flag)
412 		change_code();
413 
414 	    if (u_flag || a_flag || B_flag) {
415 		if (!t_flag) {
416 		    printf("\nWe haven't changed the partition table yet.  ");
417 		    printf("This is your last chance.\n");
418 		}
419 		print_s0(-1);
420 		if (!t_flag) {
421 		    if (ok("Should we write new partition table?"))
422 			write_s0();
423 		} else {
424 		    printf("\n-t flag specified -- partition table not written.\n");
425 		}
426 	    }
427 	}
428 
429 	exit(0);
430 }
431 
432 static void
433 usage()
434 {
435 	fprintf(stderr, "%s%s",
436 		"usage: fdisk [-BIaipqstu] [-b bootcode] [-1234] [disk]\n",
437  		"       fdisk -f configfile [-itv] [disk]\n");
438         exit(1);
439 }
440 
441 static void
442 print_s0(int which)
443 {
444 	int	i;
445 
446 	print_params();
447 	printf("Information from DOS bootblock is:\n");
448 	if (which == -1)
449 		for (i = 1; i <= NDOSPART; i++)
450 			printf("%d: ", i), print_part(i);
451 	else
452 		print_part(which);
453 }
454 
455 static struct dos_partition mtpart;
456 
457 static void
458 print_part(int i)
459 {
460 	struct	  dos_partition *partp;
461 	u_int64_t part_mb;
462 
463 	partp = &mboot.parts[i - 1];
464 
465 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
466 		printf("<UNUSED>\n");
467 		return;
468 	}
469 	/*
470 	 * Be careful not to overflow.
471 	 */
472 	part_mb = partp->dp_size;
473 	part_mb *= secsize;
474 	part_mb /= (1024 * 1024);
475 	printf("sysid %d (%#04x),(%s)\n", partp->dp_typ, partp->dp_typ,
476 	    get_type(partp->dp_typ));
477 	printf("    start %lu, size %lu (%ju Meg), flag %x%s\n",
478 		(u_long)partp->dp_start,
479 		(u_long)partp->dp_size,
480 		(uintmax_t)part_mb,
481 		partp->dp_flag,
482 		partp->dp_flag == ACTIVE ? " (active)" : "");
483 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
484 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
485 		,partp->dp_shd
486 		,DPSECT(partp->dp_ssect)
487 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
488 		,partp->dp_ehd
489 		,DPSECT(partp->dp_esect));
490 }
491 
492 
493 static void
494 init_boot(void)
495 {
496 #ifndef __ia64__
497 	const char *fname;
498 	int fdesc, n;
499 	struct stat sb;
500 
501 	fname = b_flag ? b_flag : "/boot/mbr";
502 	if ((fdesc = open(fname, O_RDONLY)) == -1 ||
503 	    fstat(fdesc, &sb) == -1)
504 		err(1, "%s", fname);
505 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
506 		errx(1, "%s: length must be a multiple of sector size", fname);
507 	if (mboot.bootinst != NULL)
508 		free(mboot.bootinst);
509 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
510 		errx(1, "%s: unable to allocate read buffer", fname);
511 	if ((n = read(fdesc, mboot.bootinst, mboot.bootinst_size)) == -1 ||
512 	    close(fdesc))
513 		err(1, "%s", fname);
514 	if (n != mboot.bootinst_size)
515 		errx(1, "%s: short read", fname);
516 #else
517 	if (mboot.bootinst != NULL)
518 		free(mboot.bootinst);
519 	mboot.bootinst_size = secsize;
520 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL)
521 		errx(1, "unable to allocate boot block buffer");
522 	memset(mboot.bootinst, 0, mboot.bootinst_size);
523 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
524 #endif
525 }
526 
527 
528 static void
529 init_sector0(unsigned long start)
530 {
531 	struct dos_partition *partp = &mboot.parts[0];
532 
533 	init_boot();
534 
535 	partp->dp_typ = DOSPTYP_386BSD;
536 	partp->dp_flag = ACTIVE;
537 	start = ((start + dos_sectors - 1) / dos_sectors) * dos_sectors;
538 	if(start == 0)
539 		start = dos_sectors;
540 	partp->dp_start = start;
541 	partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
542 
543 	dos(partp);
544 }
545 
546 static void
547 change_part(int i)
548 {
549     struct dos_partition *partp = &mboot.parts[i - 1];
550 
551     printf("The data for partition %d is:\n", i);
552     print_part(i);
553 
554     if (u_flag && ok("Do you want to change it?")) {
555 	int tmp;
556 
557 	if (i_flag) {
558 		bzero(partp, sizeof (*partp));
559 		if (i == 1) {
560 			init_sector0(1);
561 			printf("\nThe static data for the slice 1 has been reinitialized to:\n");
562 			print_part(i);
563 		}
564 	}
565 
566 	do {
567 		Decimal("sysid (165=FreeBSD)", partp->dp_typ, tmp);
568 		Decimal("start", partp->dp_start, tmp);
569 		Decimal("size", partp->dp_size, tmp);
570 		if (!sanitize_partition(partp)) {
571 			warnx("ERROR: failed to adjust; setting sysid to 0");
572 			partp->dp_typ = 0;
573 		}
574 
575 		if (ok("Explicitly specify beg/end address ?"))
576 		{
577 			int	tsec,tcyl,thd;
578 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
579 			thd = partp->dp_shd;
580 			tsec = DPSECT(partp->dp_ssect);
581 			Decimal("beginning cylinder", tcyl, tmp);
582 			Decimal("beginning head", thd, tmp);
583 			Decimal("beginning sector", tsec, tmp);
584 			partp->dp_scyl = DOSCYL(tcyl);
585 			partp->dp_ssect = DOSSECT(tsec,tcyl);
586 			partp->dp_shd = thd;
587 
588 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
589 			thd = partp->dp_ehd;
590 			tsec = DPSECT(partp->dp_esect);
591 			Decimal("ending cylinder", tcyl, tmp);
592 			Decimal("ending head", thd, tmp);
593 			Decimal("ending sector", tsec, tmp);
594 			partp->dp_ecyl = DOSCYL(tcyl);
595 			partp->dp_esect = DOSSECT(tsec,tcyl);
596 			partp->dp_ehd = thd;
597 		} else
598 			dos(partp);
599 
600 		print_part(i);
601 	} while (!ok("Are we happy with this entry?"));
602     }
603 }
604 
605 static void
606 print_params()
607 {
608 	printf("parameters extracted from in-core disklabel are:\n");
609 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
610 			,cyls,heads,sectors,cylsecs);
611 	if (dos_cyls > 1023 || dos_heads > 255 || dos_sectors > 63)
612 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
613 	printf("parameters to be used for BIOS calculations are:\n");
614 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
615 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
616 }
617 
618 static void
619 change_active(int which)
620 {
621 	struct dos_partition *partp = &mboot.parts[0];
622 	int active, i, new, tmp;
623 
624 	active = -1;
625 	for (i = 0; i < NDOSPART; i++) {
626 		if ((partp[i].dp_flag & ACTIVE) == 0)
627 			continue;
628 		printf("Partition %d is marked active\n", i + 1);
629 		if (active == -1)
630 			active = i + 1;
631 	}
632 	if (a_flag && which != -1)
633 		active = which;
634 	else if (active == -1)
635 		active = 1;
636 
637 	if (!ok("Do you want to change the active partition?"))
638 		return;
639 setactive:
640 	do {
641 		new = active;
642 		Decimal("active partition", new, tmp);
643 		if (new < 1 || new > 4) {
644 			printf("Active partition number must be in range 1-4."
645 					"  Try again.\n");
646 			goto setactive;
647 		}
648 		active = new;
649 	} while (!ok("Are you happy with this choice"));
650 	for (i = 0; i < NDOSPART; i++)
651 		partp[i].dp_flag = 0;
652 	if (active > 0 && active <= NDOSPART)
653 		partp[active-1].dp_flag = ACTIVE;
654 }
655 
656 static void
657 change_code()
658 {
659 	if (ok("Do you want to change the boot code?"))
660 		init_boot();
661 }
662 
663 void
664 get_params_to_use()
665 {
666 	int	tmp;
667 	print_params();
668 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
669 	{
670 		do
671 		{
672 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp);
673 			Decimal("BIOS's idea of #heads", dos_heads, tmp);
674 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp);
675 			dos_cylsecs = dos_heads * dos_sectors;
676 			print_params();
677 		}
678 		while(!ok("Are you happy with this choice"));
679 	}
680 }
681 
682 
683 /***********************************************\
684 * Change real numbers into strange dos numbers	*
685 \***********************************************/
686 static void
687 dos(struct dos_partition *partp)
688 {
689 	int cy, sec;
690 	u_int32_t end;
691 
692 	if (partp->dp_typ == 0 && partp->dp_start == 0 && partp->dp_size == 0) {
693 		memcpy(partp, &mtpart, sizeof(*partp));
694 		return;
695 	}
696 
697 	/* Start c/h/s. */
698 	partp->dp_shd = partp->dp_start % dos_cylsecs / dos_sectors;
699 	cy = partp->dp_start / dos_cylsecs;
700 	sec = partp->dp_start % dos_sectors + 1;
701 	partp->dp_scyl = DOSCYL(cy);
702 	partp->dp_ssect = DOSSECT(sec, cy);
703 
704 	/* End c/h/s. */
705 	end = partp->dp_start + partp->dp_size - 1;
706 	partp->dp_ehd = end % dos_cylsecs / dos_sectors;
707 	cy = end / dos_cylsecs;
708 	sec = end % dos_sectors + 1;
709 	partp->dp_ecyl = DOSCYL(cy);
710 	partp->dp_esect = DOSSECT(sec, cy);
711 }
712 
713 static int
714 open_disk(int flag)
715 {
716 	int rwmode;
717 
718 	/* Write mode if one of these flags are set. */
719 	rwmode = (a_flag || I_flag || B_flag || flag);
720 	fd = g_open(disk, rwmode);
721 	/* If the mode fails, try read-only if we didn't. */
722 	if (fd == -1 && errno == EPERM && rwmode)
723 		fd = g_open(disk, 0);
724 	if (fd == -1 && errno == ENXIO)
725 		return -2;
726 	if (fd == -1) {
727 		warnx("can't open device %s", disk);
728 		return -1;
729 	}
730 	if (get_params() == -1) {
731 		warnx("can't get disk parameters on %s", disk);
732 		return -1;
733 	}
734 	return fd;
735 }
736 
737 static ssize_t
738 read_disk(off_t sector, void *buf)
739 {
740 
741 	lseek(fd, (sector * 512), 0);
742 	if (secsize == 0)
743 		for (secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE;
744 		     secsize *= 2) {
745 			/* try the read */
746 			int size = read(fd, buf, secsize);
747 			if (size == secsize)
748 				/* it worked so return */
749 				return secsize;
750 		}
751 	else
752 		return read(fd, buf, secsize);
753 
754 	/* we failed to read at any of the sizes */
755 	return -1;
756 }
757 
758 static int
759 write_disk(off_t sector, void *buf)
760 {
761 	int error;
762 	struct gctl_req *grq;
763 	const char *errmsg;
764 	char fbuf[BUFSIZ], *pname;
765 	int i, fdw;
766 
767 	grq = gctl_get_handle();
768 	gctl_ro_param(grq, "verb", -1, "write MBR");
769 	gctl_ro_param(grq, "class", -1, "MBR");
770 	pname = g_providername(fd);
771 	if (pname == NULL) {
772 		warn("Error getting providername for %s", disk);
773 		return (-1);
774 	}
775 	gctl_ro_param(grq, "geom", -1, pname);
776 	gctl_ro_param(grq, "data", secsize, buf);
777 	errmsg = gctl_issue(grq);
778 	free(pname);
779 	if (errmsg == NULL) {
780 		gctl_free(grq);
781 		return(0);
782 	}
783 	if (!q_flag)	/* GEOM errors are benign, not all devices supported */
784 		warnx("%s", errmsg);
785 	gctl_free(grq);
786 
787 	error = pwrite(fd, buf, secsize, (sector * 512));
788 	if (error == secsize)
789 		return (0);
790 
791 	for (i = 1; i < 5; i++) {
792 		sprintf(fbuf, "%ss%d", disk, i);
793 		fdw = open(fbuf, O_RDWR, 0);
794 		if (fdw < 0)
795 			continue;
796 		error = ioctl(fdw, DIOCSMBR, buf);
797 		close(fdw);
798 		if (error == 0)
799 			return (0);
800 	}
801 	warnx("Failed to write sector zero");
802 	return(EINVAL);
803 }
804 
805 static int
806 get_params()
807 {
808 	int error;
809 	u_int u;
810 	off_t o;
811 
812 	error = ioctl(fd, DIOCGFWSECTORS, &u);
813 	if (error == 0)
814 		sectors = dos_sectors = u;
815 	else
816 		sectors = dos_sectors = 63;
817 
818 	error = ioctl(fd, DIOCGFWHEADS, &u);
819 	if (error == 0)
820 		heads = dos_heads = u;
821 	else
822 		heads = dos_heads = 255;
823 
824 	dos_cylsecs = cylsecs = heads * sectors;
825 	disksecs = cyls * heads * sectors;
826 
827 	u = g_sectorsize(fd);
828 	if (u <= 0)
829 		return (-1);
830 
831 	o = g_mediasize(fd);
832 	if (o < 0)
833 		return (-1);
834 	disksecs = o / u;
835 	cyls = dos_cyls = o / (u * dos_heads * dos_sectors);
836 
837 	return (disksecs);
838 }
839 
840 static int
841 read_s0()
842 {
843 	int i;
844 
845 	mboot.bootinst_size = secsize;
846 	if (mboot.bootinst != NULL)
847 		free(mboot.bootinst);
848 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
849 		warnx("unable to allocate buffer to read fdisk "
850 		      "partition table");
851 		return -1;
852 	}
853 	if (read_disk(0, mboot.bootinst) == -1) {
854 		warnx("can't read fdisk partition table");
855 		return -1;
856 	}
857 	if (le16dec(&mboot.bootinst[DOSMAGICOFFSET]) != DOSMAGIC) {
858 		warnx("invalid fdisk partition table found");
859 		/* So should we initialize things */
860 		return -1;
861 	}
862 	for (i = 0; i < NDOSPART; i++)
863 		dos_partition_dec(
864 		    &mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
865 		    &mboot.parts[i]);
866 	return 0;
867 }
868 
869 static int
870 write_s0()
871 {
872 	int	sector, i;
873 
874 	if (iotest) {
875 		print_s0(-1);
876 		return 0;
877 	}
878 	for(i = 0; i < NDOSPART; i++)
879 		dos_partition_enc(&mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
880 		    &mboot.parts[i]);
881 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
882 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
883 		if (write_disk(sector,
884 			       &mboot.bootinst[sector * secsize]) == -1) {
885 			warn("can't write fdisk partition table");
886 			return -1;
887 		}
888 	return(0);
889 }
890 
891 
892 static int
893 ok(const char *str)
894 {
895 	printf("%s [n] ", str);
896 	fflush(stdout);
897 	if (fgets(lbuf, LBUF, stdin) == NULL)
898 		exit(1);
899 	lbuf[strlen(lbuf)-1] = 0;
900 
901 	if (*lbuf &&
902 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
903 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
904 		return 1;
905 	else
906 		return 0;
907 }
908 
909 static int
910 decimal(const char *str, int *num, int deflt)
911 {
912 	int acc = 0, c;
913 	char *cp;
914 
915 	while (1) {
916 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
917 		fflush(stdout);
918 		if (fgets(lbuf, LBUF, stdin) == NULL)
919 			exit(1);
920 		lbuf[strlen(lbuf)-1] = 0;
921 
922 		if (!*lbuf)
923 			return 0;
924 
925 		cp = lbuf;
926 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
927 		if (!c)
928 			return 0;
929 		while ((c = *cp++)) {
930 			if (c <= '9' && c >= '0')
931 				acc = acc * 10 + c - '0';
932 			else
933 				break;
934 		}
935 		if (c == ' ' || c == '\t')
936 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
937 		if (!c) {
938 			*num = acc;
939 			return 1;
940 		} else
941 			printf("%s is an invalid decimal number.  Try again.\n",
942 				lbuf);
943 	}
944 
945 }
946 
947 static const char *
948 get_type(int type)
949 {
950 	int	numentries = (sizeof(part_types)/sizeof(struct part_type));
951 	int	counter = 0;
952 	struct	part_type *ptr = part_types;
953 
954 
955 	while(counter < numentries) {
956 		if(ptr->type == type)
957 			return(ptr->name);
958 		ptr++;
959 		counter++;
960 	}
961 	return("unknown");
962 }
963 
964 
965 static void
966 parse_config_line(char *line, CMD *command)
967 {
968     char	*cp, *end;
969 
970     cp = line;
971     while (1) {
972 	memset(command, 0, sizeof(*command));
973 
974 	while (isspace(*cp)) ++cp;
975 	if (*cp == '\0' || *cp == '#')
976 	    break;
977 	command->cmd = *cp++;
978 
979 	/*
980 	 * Parse args
981 	 */
982 	    while (1) {
983 	    while (isspace(*cp)) ++cp;
984 	    if (*cp == '#')
985 		break;		/* found comment */
986 	    if (isalpha(*cp))
987 		command->args[command->n_args].argtype = *cp++;
988 	    if (!isdigit(*cp))
989 		break;		/* assume end of line */
990 	    end = NULL;
991 	    command->args[command->n_args].arg_val = strtol(cp, &end, 0);
992 	    if (cp == end)
993 		break;		/* couldn't parse number */
994 	    cp = end;
995 	    command->n_args++;
996 	}
997 	break;
998     }
999 }
1000 
1001 
1002 static int
1003 process_geometry(CMD *command)
1004 {
1005     int		status = 1, i;
1006 
1007     while (1) {
1008 	geom_processed = 1;
1009 	    if (part_processed) {
1010 	    warnx(
1011 	"ERROR line %d: the geometry specification line must occur before\n\
1012     all partition specifications",
1013 		    current_line_number);
1014 	    status = 0;
1015 	    break;
1016 	}
1017 	    if (command->n_args != 3) {
1018 	    warnx("ERROR line %d: incorrect number of geometry args",
1019 		    current_line_number);
1020 	    status = 0;
1021 	    break;
1022 	}
1023 	    dos_cyls = 0;
1024 	    dos_heads = 0;
1025 	    dos_sectors = 0;
1026 	    for (i = 0; i < 3; ++i) {
1027 		    switch (command->args[i].argtype) {
1028 	    case 'c':
1029 		dos_cyls = command->args[i].arg_val;
1030 		break;
1031 	    case 'h':
1032 		dos_heads = command->args[i].arg_val;
1033 		break;
1034 	    case 's':
1035 		dos_sectors = command->args[i].arg_val;
1036 		break;
1037 	    default:
1038 		warnx(
1039 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1040 			current_line_number, command->args[i].argtype,
1041 			command->args[i].argtype);
1042 		status = 0;
1043 		break;
1044 	    }
1045 	}
1046 	if (status == 0)
1047 	    break;
1048 
1049 	dos_cylsecs = dos_heads * dos_sectors;
1050 
1051 	/*
1052 	 * Do sanity checks on parameter values
1053 	 */
1054 	    if (dos_cyls == 0) {
1055 	    warnx("ERROR line %d: number of cylinders not specified",
1056 		    current_line_number);
1057 	    status = 0;
1058 	}
1059 	    if (dos_cyls > 1024) {
1060 	    warnx(
1061 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1062     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1063     is dedicated to FreeBSD)",
1064 		    current_line_number, dos_cyls);
1065 	}
1066 
1067 	    if (dos_heads == 0) {
1068 	    warnx("ERROR line %d: number of heads not specified",
1069 		    current_line_number);
1070 	    status = 0;
1071 	    } else if (dos_heads > 256) {
1072 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1073 		    current_line_number);
1074 	    status = 0;
1075 	}
1076 
1077 	    if (dos_sectors == 0) {
1078 	    warnx("ERROR line %d: number of sectors not specified",
1079 		    current_line_number);
1080 	    status = 0;
1081 	    } else if (dos_sectors > 63) {
1082 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1083 		    current_line_number);
1084 	    status = 0;
1085 	}
1086 
1087 	break;
1088     }
1089     return (status);
1090 }
1091 
1092 
1093 static int
1094 process_partition(CMD *command)
1095 {
1096     int				status = 0, partition;
1097     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1098     u_int32_t			adj_size, max_end;
1099     struct dos_partition	*partp;
1100 
1101 	while (1) {
1102 	part_processed = 1;
1103 		if (command->n_args != 4) {
1104 	    warnx("ERROR line %d: incorrect number of partition args",
1105 		    current_line_number);
1106 	    break;
1107 	}
1108 	partition = command->args[0].arg_val;
1109 		if (partition < 1 || partition > 4) {
1110 	    warnx("ERROR line %d: invalid partition number %d",
1111 		    current_line_number, partition);
1112 	    break;
1113 	}
1114 	partp = &mboot.parts[partition - 1];
1115 	bzero(partp, sizeof (*partp));
1116 	partp->dp_typ = command->args[1].arg_val;
1117 	partp->dp_start = command->args[2].arg_val;
1118 	partp->dp_size = command->args[3].arg_val;
1119 	max_end = partp->dp_start + partp->dp_size;
1120 
1121 	if (partp->dp_typ == 0) {
1122 	    /*
1123 	     * Get out, the partition is marked as unused.
1124 	     */
1125 	    /*
1126 	     * Insure that it's unused.
1127 	     */
1128 	    bzero(partp, sizeof(*partp));
1129 	    status = 1;
1130 	    break;
1131 	}
1132 
1133 	/*
1134 	 * Adjust start upwards, if necessary, to fall on a head boundary.
1135 	 */
1136 		if (partp->dp_start % dos_sectors != 0) {
1137 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1138 	    if (max_end < dos_sectors ||
1139 			    prev_head_boundary > max_end - dos_sectors) {
1140 		/*
1141 		 * Can't go past end of partition
1142 		 */
1143 		warnx(
1144 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1145     a head boundary",
1146 			current_line_number, partition);
1147 		break;
1148 	    }
1149 	    warnx(
1150 	"WARNING: adjusting start offset of partition %d\n\
1151     from %u to %u, to fall on a head boundary",
1152 		    partition, (u_int)partp->dp_start,
1153 		    (u_int)(prev_head_boundary + dos_sectors));
1154 	    partp->dp_start = prev_head_boundary + dos_sectors;
1155 	}
1156 
1157 	/*
1158 	 * Adjust size downwards, if necessary, to fall on a cylinder
1159 	 * boundary.
1160 	 */
1161 	prev_cyl_boundary =
1162 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1163 	if (prev_cyl_boundary > partp->dp_start)
1164 	    adj_size = prev_cyl_boundary - partp->dp_start;
1165 		else {
1166 	    warnx(
1167 	"ERROR: could not adjust partition to start on a head boundary\n\
1168     and end on a cylinder boundary.");
1169 	    return (0);
1170 	}
1171 		if (adj_size != partp->dp_size) {
1172 	    warnx(
1173 	"WARNING: adjusting size of partition %d from %u to %u\n\
1174     to end on a cylinder boundary",
1175 		    partition, (u_int)partp->dp_size, (u_int)adj_size);
1176 	    partp->dp_size = adj_size;
1177 	}
1178 		if (partp->dp_size == 0) {
1179 	    warnx("ERROR line %d: size of partition %d is zero",
1180 		    current_line_number, partition);
1181 	    break;
1182 	}
1183 
1184 	dos(partp);
1185 	status = 1;
1186 	break;
1187     }
1188     return (status);
1189 }
1190 
1191 
1192 static int
1193 process_active(CMD *command)
1194 {
1195     int				status = 0, partition, i;
1196     struct dos_partition	*partp;
1197 
1198 	while (1) {
1199 	active_processed = 1;
1200 		if (command->n_args != 1) {
1201 	    warnx("ERROR line %d: incorrect number of active args",
1202 		    current_line_number);
1203 	    status = 0;
1204 	    break;
1205 	}
1206 	partition = command->args[0].arg_val;
1207 		if (partition < 1 || partition > 4) {
1208 	    warnx("ERROR line %d: invalid partition number %d",
1209 		    current_line_number, partition);
1210 	    break;
1211 	}
1212 	/*
1213 	 * Reset active partition
1214 	 */
1215 	partp = mboot.parts;
1216 	for (i = 0; i < NDOSPART; i++)
1217 	    partp[i].dp_flag = 0;
1218 	partp[partition-1].dp_flag = ACTIVE;
1219 
1220 	status = 1;
1221 	break;
1222     }
1223     return (status);
1224 }
1225 
1226 
1227 static int
1228 process_line(char *line)
1229 {
1230     CMD		command;
1231     int		status = 1;
1232 
1233 	while (1) {
1234 	parse_config_line(line, &command);
1235 		switch (command.cmd) {
1236 	case 0:
1237 	    /*
1238 	     * Comment or blank line
1239 	     */
1240 	    break;
1241 	case 'g':
1242 	    /*
1243 	     * Set geometry
1244 	     */
1245 	    status = process_geometry(&command);
1246 	    break;
1247 	case 'p':
1248 	    status = process_partition(&command);
1249 	    break;
1250 	case 'a':
1251 	    status = process_active(&command);
1252 	    break;
1253 	default:
1254 	    status = 0;
1255 	    break;
1256 	}
1257 	break;
1258     }
1259     return (status);
1260 }
1261 
1262 
1263 static int
1264 read_config(char *config_file)
1265 {
1266     FILE	*fp = NULL;
1267     int		status = 1;
1268     char	buf[1010];
1269 
1270 	while (1) {
1271 		if (strcmp(config_file, "-") != 0) {
1272 	    /*
1273 	     * We're not reading from stdin
1274 	     */
1275 			if ((fp = fopen(config_file, "r")) == NULL) {
1276 		status = 0;
1277 		break;
1278 	    }
1279 		} else {
1280 	    fp = stdin;
1281 	}
1282 	current_line_number = 0;
1283 		while (!feof(fp)) {
1284 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1285 		break;
1286 	    ++current_line_number;
1287 	    status = process_line(buf);
1288 	    if (status == 0)
1289 		break;
1290 	    }
1291 	break;
1292     }
1293 	if (fp) {
1294 	/*
1295 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1296 	 */
1297 	fclose(fp);
1298     }
1299     return (status);
1300 }
1301 
1302 
1303 static void
1304 reset_boot(void)
1305 {
1306     int				i;
1307     struct dos_partition	*partp;
1308 
1309     init_boot();
1310     for (i = 0; i < 4; ++i) {
1311 	partp = &mboot.parts[i];
1312 	bzero(partp, sizeof(*partp));
1313     }
1314 }
1315 
1316 static int
1317 sanitize_partition(struct dos_partition *partp)
1318 {
1319     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1320     u_int32_t			max_end, size, start;
1321 
1322     start = partp->dp_start;
1323     size = partp->dp_size;
1324     max_end = start + size;
1325     /* Only allow a zero size if the partition is being marked unused. */
1326     if (size == 0) {
1327 	if (start == 0 && partp->dp_typ == 0)
1328 	    return (1);
1329 	warnx("ERROR: size of partition is zero");
1330 	return (0);
1331     }
1332     /* Return if no adjustment is necessary. */
1333     if (start % dos_sectors == 0 && (start + size) % dos_sectors == 0)
1334 	return (1);
1335 
1336     if (start == 0) {
1337 	    warnx("WARNING: partition overlaps with partition table");
1338 	    if (ok("Correct this automatically?"))
1339 		    start = dos_sectors;
1340     }
1341     if (start % dos_sectors != 0)
1342 	warnx("WARNING: partition does not start on a head boundary");
1343     if ((start  +size) % dos_sectors != 0)
1344 	warnx("WARNING: partition does not end on a cylinder boundary");
1345     warnx("WARNING: this may confuse the BIOS or some operating systems");
1346     if (!ok("Correct this automatically?"))
1347 	return (1);
1348 
1349     /*
1350      * Adjust start upwards, if necessary, to fall on a head boundary.
1351      */
1352     if (start % dos_sectors != 0) {
1353 	prev_head_boundary = start / dos_sectors * dos_sectors;
1354 	if (max_end < dos_sectors ||
1355 	    prev_head_boundary >= max_end - dos_sectors) {
1356 	    /*
1357 	     * Can't go past end of partition
1358 	     */
1359 	    warnx(
1360     "ERROR: unable to adjust start of partition to fall on a head boundary");
1361 	    return (0);
1362         }
1363 	start = prev_head_boundary + dos_sectors;
1364     }
1365 
1366     /*
1367      * Adjust size downwards, if necessary, to fall on a cylinder
1368      * boundary.
1369      */
1370     prev_cyl_boundary = ((start + size) / dos_cylsecs) * dos_cylsecs;
1371     if (prev_cyl_boundary > start)
1372 	size = prev_cyl_boundary - start;
1373     else {
1374 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1375     and end on a cylinder boundary.");
1376 	return (0);
1377     }
1378 
1379     /* Finally, commit any changes to partp and return. */
1380     if (start != partp->dp_start) {
1381 	warnx("WARNING: adjusting start offset of partition to %u",
1382 	    (u_int)start);
1383 	partp->dp_start = start;
1384     }
1385     if (size != partp->dp_size) {
1386 	warnx("WARNING: adjusting size of partition to %u", (u_int)size);
1387 	partp->dp_size = size;
1388     }
1389 
1390     return (1);
1391 }
1392 
1393 /*
1394  * Try figuring out the root device's canonical disk name.
1395  * The following choices are considered:
1396  *   /dev/ad0s1a     => /dev/ad0
1397  *   /dev/da0a       => /dev/da0
1398  *   /dev/vinum/root => /dev/vinum/root
1399  */
1400 static char *
1401 get_rootdisk(void)
1402 {
1403 	struct statfs rootfs;
1404 	regex_t re;
1405 #define NMATCHES 2
1406 	regmatch_t rm[NMATCHES];
1407 	char *s;
1408 	int rv;
1409 
1410 	if (statfs("/", &rootfs) == -1)
1411 		err(1, "statfs(\"/\")");
1412 
1413 	if ((rv = regcomp(&re, "^(/dev/[a-z/]+[0-9]+)([sp][0-9]+)?[a-h]?$",
1414 		    REG_EXTENDED)) != 0)
1415 		errx(1, "regcomp() failed (%d)", rv);
1416 	if ((rv = regexec(&re, rootfs.f_mntfromname, NMATCHES, rm, 0)) != 0)
1417 		errx(1,
1418 "mounted root fs resource doesn't match expectations (regexec returned %d)",
1419 		    rv);
1420 	if ((s = malloc(rm[1].rm_eo - rm[1].rm_so + 1)) == NULL)
1421 		errx(1, "out of memory");
1422 	memcpy(s, rootfs.f_mntfromname + rm[1].rm_so,
1423 	    rm[1].rm_eo - rm[1].rm_so);
1424 	s[rm[1].rm_eo - rm[1].rm_so] = 0;
1425 
1426 	return s;
1427 }
1428