xref: /freebsd/sbin/fdisk/fdisk.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
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 static int iotest;
51 
52 #define NO_DISK_SECTORS ((u_int32_t)-1)
53 #define NO_TRACK_CYLINDERS 1023
54 #define NO_TRACK_HEADS 255
55 #define NO_TRACK_SECTORS 63
56 #define LBUF 100
57 static char lbuf[LBUF];
58 
59 /*
60  *
61  * Ported to 386bsd by Julian Elischer  Thu Oct 15 20:26:46 PDT 1992
62  *
63  * 14-Dec-89  Robert Baron (rvb) at Carnegie-Mellon University
64  *	Copyright (c) 1989	Robert. V. Baron
65  *	Created.
66  */
67 
68 #define Decimal(str, ans, tmp, maxval) if (decimal(str, &tmp, ans, maxval)) ans = tmp
69 
70 #define RoundCyl(x) ((((x) + cylsecs - 1) / cylsecs) * cylsecs)
71 
72 #define MAX_SEC_SIZE 2048	/* maximum section size that is supported */
73 #define MIN_SEC_SIZE 512	/* the sector size to start sensing at */
74 static int secsize = 0;		/* the sensed sector size */
75 
76 static char *disk;
77 
78 static int cyls, sectors, heads, cylsecs, disksecs;
79 
80 struct mboot {
81 	unsigned char *bootinst;  /* boot code */
82 	off_t bootinst_size;
83 	struct	dos_partition parts[NDOSPART];
84 };
85 
86 static struct mboot mboot;
87 static int fd;
88 
89 #define ACTIVE 0x80
90 
91 static uint dos_cyls;
92 static uint dos_heads;
93 static uint dos_sectors;
94 static uint dos_cylsecs;
95 
96 #define DOSSECT(s,c) ((s & 0x3f) | ((c >> 2) & 0xc0))
97 #define DOSCYL(c)	(c & 0xff)
98 
99 #define MAX_ARGS	10
100 
101 static int	current_line_number;
102 
103 static int	geom_processed = 0;
104 static int	part_processed = 0;
105 static int	active_processed = 0;
106 
107 typedef struct cmd {
108     char		cmd;
109     int			n_args;
110     struct arg {
111 	char		argtype;
112 	unsigned long	arg_val;
113 	char *		arg_str;
114     }			args[MAX_ARGS];
115 } CMD;
116 
117 static int B_flag  = 0;		/* replace boot code */
118 static int I_flag  = 0;		/* use entire disk for FreeBSD */
119 static int a_flag  = 0;		/* set active partition */
120 static char *b_flag = NULL;	/* path to boot code */
121 static int i_flag  = 0;		/* replace partition data */
122 static int q_flag  = 0;		/* Be quiet */
123 static int u_flag  = 0;		/* update partition data */
124 static int s_flag  = 0;		/* Print a summary and exit */
125 static int t_flag  = 0;		/* test only */
126 static char *f_flag = NULL;	/* Read config info from file */
127 static int v_flag  = 0;		/* Be verbose */
128 static int print_config_flag = 0;
129 
130 /*
131  * A list of partition types, probably outdated.
132  */
133 static const char *const part_types[256] = {
134 	[0x00] = "unused",
135 	[0x01] = "Primary DOS with 12 bit FAT",
136 	[0x02] = "XENIX / file system",
137 	[0x03] = "XENIX /usr file system",
138 	[0x04] = "Primary DOS with 16 bit FAT (< 32MB)",
139 	[0x05] = "Extended DOS",
140 	[0x06] = "Primary DOS, 16 bit FAT (>= 32MB)",
141 	[0x07] = "NTFS, OS/2 HPFS, QNX-2 (16 bit) or Advanced UNIX",
142 	[0x08] = "AIX file system or SplitDrive",
143 	[0x09] = "AIX boot partition or Coherent",
144 	[0x0A] = "OS/2 Boot Manager, OPUS or Coherent swap",
145 	[0x0B] = "DOS or Windows 95 with 32 bit FAT",
146 	[0x0C] = "DOS or Windows 95 with 32 bit FAT (LBA)",
147 	[0x0E] = "Primary 'big' DOS (>= 32MB, LBA)",
148 	[0x0F] = "Extended DOS (LBA)",
149 	[0x10] = "OPUS",
150 	[0x11] = "OS/2 BM: hidden DOS with 12-bit FAT",
151 	[0x12] = "Compaq diagnostics",
152 	[0x14] = "OS/2 BM: hidden DOS with 16-bit FAT (< 32MB)",
153 	[0x16] = "OS/2 BM: hidden DOS with 16-bit FAT (>= 32MB)",
154 	[0x17] = "OS/2 BM: hidden IFS (e.g. HPFS)",
155 	[0x18] = "AST Windows swapfile",
156 	[0x1b] = "ASUS Recovery partition (NTFS)",
157 	[0x24] = "NEC DOS",
158 	[0x3C] = "PartitionMagic recovery",
159 	[0x39] = "plan9",
160 	[0x40] = "VENIX 286",
161 	[0x41] = "Linux/MINIX (sharing disk with DRDOS)",
162 	[0x42] = "SFS or Linux swap (sharing disk with DRDOS)",
163 	[0x43] = "Linux native (sharing disk with DRDOS)",
164 	[0x4D] = "QNX 4.2 Primary",
165 	[0x4E] = "QNX 4.2 Secondary",
166 	[0x4F] = "QNX 4.2 Tertiary",
167 	[0x50] = "DM (disk manager)",
168 	[0x51] = "DM6 Aux1 (or Novell)",
169 	[0x52] = "CP/M or Microport SysV/AT",
170 	[0x53] = "DM6 Aux3",
171 	[0x54] = "DM6",
172 	[0x55] = "EZ-Drive (disk manager)",
173 	[0x56] = "Golden Bow (disk manager)",
174 	[0x5c] = "Priam Edisk (disk manager)", /* according to S. Widlake */
175 	[0x61] = "SpeedStor",
176 	[0x63] = "System V/386 (such as ISC UNIX), GNU HURD or Mach",
177 	[0x64] = "Novell Netware/286 2.xx",
178 	[0x65] = "Novell Netware/386 3.xx",
179 	[0x70] = "DiskSecure Multi-Boot",
180 	[0x75] = "PCIX",
181 	[0x77] = "QNX4.x",
182 	[0x78] = "QNX4.x 2nd part",
183 	[0x79] = "QNX4.x 3rd part",
184 	[0x80] = "Minix until 1.4a",
185 	[0x81] = "Minix since 1.4b, early Linux partition or Mitac disk manager",
186 	[0x82] = "Linux swap or Solaris x86",
187 	[0x83] = "Linux native",
188 	[0x84] = "OS/2 hidden C: drive",
189 	[0x85] = "Linux extended",
190 	[0x86] = "NTFS volume set??",
191 	[0x87] = "NTFS volume set??",
192 	[0x93] = "Amoeba file system",
193 	[0x94] = "Amoeba bad block table",
194 	[0x9F] = "BSD/OS",
195 	[0xA0] = "Suspend to Disk",
196 	[0xA5] = "FreeBSD/NetBSD/386BSD",
197 	[0xA6] = "OpenBSD",
198 	[0xA7] = "NeXTSTEP",
199 	[0xA9] = "NetBSD",
200 	[0xAC] = "IBM JFS",
201 	[0xAF] = "HFS+",
202 	[0xB7] = "BSDI BSD/386 file system",
203 	[0xB8] = "BSDI BSD/386 swap",
204 	[0xBE] = "Solaris x86 boot",
205 	[0xBF] = "Solaris x86 (new)",
206 	[0xC1] = "DRDOS/sec with 12-bit FAT",
207 	[0xC4] = "DRDOS/sec with 16-bit FAT (< 32MB)",
208 	[0xC6] = "DRDOS/sec with 16-bit FAT (>= 32MB)",
209 	[0xC7] = "Syrinx",
210 	[0xDB] = "CP/M, Concurrent CP/M, Concurrent DOS or CTOS",
211 	[0xDE] = "DELL Utilities - FAT filesystem",
212 	[0xE1] = "DOS access or SpeedStor with 12-bit FAT extended partition",
213 	[0xE3] = "DOS R/O or SpeedStor",
214 	[0xE4] = "SpeedStor with 16-bit FAT extended partition < 1024 cyl.",
215 	[0xEB] = "BeOS file system",
216 	[0xEE] = "EFI GPT",
217 	[0xEF] = "EFI System Partition",
218 	[0xF1] = "SpeedStor",
219 	[0xF2] = "DOS 3.3+ Secondary",
220 	[0xF4] = "SpeedStor large partition",
221 	[0xFB] = "VMware VMFS",
222 	[0xFE] = "SpeedStor >1024 cyl. or LANstep",
223 	[0xFF] = "Xenix bad blocks table",
224 };
225 
226 static const char *
227 get_type(int t)
228 {
229 	const char *ret;
230 
231 	ret = (t >= 0 && t <= 255) ? part_types[t] : NULL;
232 	return ret ? ret : "unknown";
233 }
234 
235 
236 static int geom_class_available(const char *);
237 static void print_s0(void);
238 static void print_part(const struct dos_partition *);
239 static void init_sector0(unsigned long start);
240 static void init_boot(void);
241 static void change_part(int i);
242 static void print_params(void);
243 static void change_active(int which);
244 static void change_code(void);
245 static void get_params_to_use(void);
246 static char *get_rootdisk(void);
247 static void dos(struct dos_partition *partp);
248 static int open_disk(int flag);
249 static ssize_t read_disk(off_t sector, void *buf);
250 static int write_disk(off_t sector, void *buf);
251 static int get_params(void);
252 static int read_s0(void);
253 static int write_s0(void);
254 static int ok(const char *str);
255 static int decimal(const char *str, int *num, int deflt, uint32_t maxval);
256 static int read_config(char *config_file);
257 static void reset_boot(void);
258 static int sanitize_partition(struct dos_partition *);
259 static void usage(void);
260 
261 int
262 main(int argc, char *argv[])
263 {
264 	int	c, i;
265 	int	partition = -1;
266 	struct	dos_partition *partp;
267 
268 	while ((c = getopt(argc, argv, "BIab:f:ipqstuv1234")) != -1)
269 		switch (c) {
270 		case 'B':
271 			B_flag = 1;
272 			break;
273 		case 'I':
274 			I_flag = 1;
275 			break;
276 		case 'a':
277 			a_flag = 1;
278 			break;
279 		case 'b':
280 			b_flag = optarg;
281 			break;
282 		case 'f':
283 			f_flag = optarg;
284 			break;
285 		case 'i':
286 			i_flag = 1;
287 			break;
288 		case 'p':
289 			print_config_flag = 1;
290 			break;
291 		case 'q':
292 			q_flag = 1;
293 			break;
294 		case 's':
295 			s_flag = 1;
296 			break;
297 		case 't':
298 			t_flag = 1;
299 			break;
300 		case 'u':
301 			u_flag = 1;
302 			break;
303 		case 'v':
304 			v_flag = 1;
305 			break;
306 		case '1':
307 		case '2':
308 		case '3':
309 		case '4':
310 			partition = c - '0';
311 			break;
312 		default:
313 			usage();
314 		}
315 	if (f_flag || i_flag)
316 		u_flag = 1;
317 	if (t_flag)
318 		v_flag = 1;
319 	argc -= optind;
320 	argv += optind;
321 
322 	if (argc == 0) {
323 		disk = get_rootdisk();
324 	} else {
325 		disk = g_device_path(argv[0]);
326 		if (disk == NULL)
327 			err(1, "unable to get correct path for %s", argv[0]);
328 	}
329 	if (open_disk(u_flag) < 0)
330 		err(1, "cannot open disk %s", disk);
331 
332 	/* (abu)use mboot.bootinst to probe for the sector size */
333 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
334 		err(1, "cannot allocate buffer to determine disk sector size");
335 	if (read_disk(0, mboot.bootinst) == -1)
336 		errx(1, "could not detect sector size");
337 	free(mboot.bootinst);
338 	mboot.bootinst = NULL;
339 
340 	if (print_config_flag) {
341 		if (read_s0())
342 			err(1, "read_s0");
343 
344 		printf("# %s\n", disk);
345 		printf("g c%d h%d s%d\n", dos_cyls, dos_heads, dos_sectors);
346 
347 		for (i = 0; i < NDOSPART; i++) {
348 			partp = &mboot.parts[i];
349 
350 			if (partp->dp_start == 0 && partp->dp_size == 0)
351 				continue;
352 
353 			printf("p %d 0x%02x %lu %lu\n", i + 1, partp->dp_typ,
354 			    (u_long)partp->dp_start, (u_long)partp->dp_size);
355 
356 			/* Fill flags for the partition. */
357 			if (partp->dp_flag & 0x80)
358 				printf("a %d\n", i + 1);
359 		}
360 		exit(0);
361 	}
362 	if (s_flag) {
363 		if (read_s0())
364 			err(1, "read_s0");
365 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
366 		    dos_sectors);
367 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
368 		for (i = 0; i < NDOSPART; i++) {
369 			partp = &mboot.parts[i];
370 			if (partp->dp_start == 0 && partp->dp_size == 0)
371 				continue;
372 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", i + 1,
373 			    (u_long) partp->dp_start,
374 			    (u_long) partp->dp_size, partp->dp_typ,
375 			    partp->dp_flag);
376 		}
377 		exit(0);
378 	}
379 
380 	printf("******* Working on device %s *******\n",disk);
381 
382 	if (I_flag) {
383 		read_s0();
384 		reset_boot();
385 		partp = &mboot.parts[0];
386 		partp->dp_typ = DOSPTYP_386BSD;
387 		partp->dp_flag = ACTIVE;
388 		partp->dp_start = dos_sectors;
389 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs -
390 		    dos_sectors;
391 		dos(partp);
392 		if (v_flag)
393 			print_s0();
394 		if (!t_flag)
395 			write_s0();
396 		exit(0);
397 	}
398 	if (f_flag) {
399 	    if (read_s0() || i_flag)
400 		reset_boot();
401 	    if (!read_config(f_flag))
402 		exit(1);
403 	    if (v_flag)
404 		print_s0();
405 	    if (!t_flag)
406 		write_s0();
407 	} else {
408 	    if(u_flag)
409 		get_params_to_use();
410 	    else
411 		print_params();
412 
413 	    if (read_s0())
414 		init_sector0(dos_sectors);
415 
416 	    printf("Media sector size is %d\n", secsize);
417 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
418 	    printf("Information from DOS bootblock is:\n");
419 	    if (partition == -1)
420 		for (i = 1; i <= NDOSPART; i++)
421 		    change_part(i);
422 	    else
423 		change_part(partition);
424 
425 	    if (u_flag || a_flag)
426 		change_active(partition);
427 
428 	    if (B_flag)
429 		change_code();
430 
431 	    if (u_flag || a_flag || B_flag) {
432 		if (!t_flag) {
433 		    printf("\nWe haven't changed the partition table yet.  ");
434 		    printf("This is your last chance.\n");
435 		}
436 		print_s0();
437 		if (!t_flag) {
438 		    if (ok("Should we write new partition table?"))
439 			write_s0();
440 		} else {
441 		    printf("\n-t flag specified -- partition table not written.\n");
442 		}
443 	    }
444 	}
445 
446 	exit(0);
447 }
448 
449 static void
450 usage()
451 {
452 	fprintf(stderr, "%s%s",
453 		"usage: fdisk [-BIaipqstu] [-b bootcode] [-1234] [disk]\n",
454  		"       fdisk -f configfile [-itv] [disk]\n");
455         exit(1);
456 }
457 
458 static void
459 print_s0(void)
460 {
461 	int	i;
462 
463 	print_params();
464 	printf("Information from DOS bootblock is:\n");
465 	for (i = 1; i <= NDOSPART; i++) {
466 		printf("%d: ", i);
467 		print_part(&mboot.parts[i - 1]);
468 	}
469 }
470 
471 static struct dos_partition mtpart;
472 
473 static void
474 print_part(const struct dos_partition *partp)
475 {
476 	u_int64_t part_mb;
477 
478 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
479 		printf("<UNUSED>\n");
480 		return;
481 	}
482 	/*
483 	 * Be careful not to overflow.
484 	 */
485 	part_mb = partp->dp_size;
486 	part_mb *= secsize;
487 	part_mb /= (1024 * 1024);
488 	printf("sysid %d (%#04x),(%s)\n", partp->dp_typ, partp->dp_typ,
489 	    get_type(partp->dp_typ));
490 	printf("    start %lu, size %lu (%ju Meg), flag %x%s\n",
491 		(u_long)partp->dp_start,
492 		(u_long)partp->dp_size,
493 		(uintmax_t)part_mb,
494 		partp->dp_flag,
495 		partp->dp_flag == ACTIVE ? " (active)" : "");
496 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
497 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
498 		,partp->dp_shd
499 		,DPSECT(partp->dp_ssect)
500 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
501 		,partp->dp_ehd
502 		,DPSECT(partp->dp_esect));
503 }
504 
505 
506 static void
507 init_boot(void)
508 {
509 #ifndef __ia64__
510 	const char *fname;
511 	int fdesc, n;
512 	struct stat sb;
513 
514 	fname = b_flag ? b_flag : "/boot/mbr";
515 	if ((fdesc = open(fname, O_RDONLY)) == -1 ||
516 	    fstat(fdesc, &sb) == -1)
517 		err(1, "%s", fname);
518 	if (sb.st_size == 0)
519 		errx(1, "%s is empty, must not be.", fname);
520 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
521 		errx(1, "%s: length must be a multiple of sector size", fname);
522 	if (mboot.bootinst != NULL)
523 		free(mboot.bootinst);
524 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
525 		errx(1, "%s: unable to allocate read buffer", fname);
526 	if ((n = read(fdesc, mboot.bootinst, mboot.bootinst_size)) == -1 ||
527 	    close(fdesc))
528 		err(1, "%s", fname);
529 	if (n != mboot.bootinst_size)
530 		errx(1, "%s: short read", fname);
531 #else
532 	if (mboot.bootinst != NULL)
533 		free(mboot.bootinst);
534 	mboot.bootinst_size = secsize;
535 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL)
536 		errx(1, "unable to allocate boot block buffer");
537 	memset(mboot.bootinst, 0, mboot.bootinst_size);
538 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
539 #endif
540 }
541 
542 
543 static void
544 init_sector0(unsigned long start)
545 {
546 	struct dos_partition *partp = &mboot.parts[0];
547 
548 	init_boot();
549 
550 	partp->dp_typ = DOSPTYP_386BSD;
551 	partp->dp_flag = ACTIVE;
552 	start = ((start + dos_sectors - 1) / dos_sectors) * dos_sectors;
553 	if(start == 0)
554 		start = dos_sectors;
555 	partp->dp_start = start;
556 	partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
557 
558 	dos(partp);
559 }
560 
561 static void
562 change_part(int i)
563 {
564     struct dos_partition *partp = &mboot.parts[i - 1];
565 
566     printf("The data for partition %d is:\n", i);
567     print_part(partp);
568 
569     if (u_flag && ok("Do you want to change it?")) {
570 	int tmp;
571 
572 	if (i_flag) {
573 	    bzero(partp, sizeof (*partp));
574 	    if (i == 1) {
575 		init_sector0(1);
576 		printf("\nThe static data for the slice 1 has been reinitialized to:\n");
577 		print_part(partp);
578 	    }
579 	}
580 
581 	do {
582 		Decimal("sysid (165=FreeBSD)", partp->dp_typ, tmp, 255);
583 		Decimal("start", partp->dp_start, tmp, NO_DISK_SECTORS);
584 		Decimal("size", partp->dp_size, tmp, NO_DISK_SECTORS);
585 		if (!sanitize_partition(partp)) {
586 			warnx("ERROR: failed to adjust; setting sysid to 0");
587 			partp->dp_typ = 0;
588 		}
589 
590 		if (ok("Explicitly specify beg/end address ?"))
591 		{
592 			int	tsec,tcyl,thd;
593 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
594 			thd = partp->dp_shd;
595 			tsec = DPSECT(partp->dp_ssect);
596 			Decimal("beginning cylinder", tcyl, tmp, NO_TRACK_CYLINDERS);
597 			Decimal("beginning head", thd, tmp, NO_TRACK_HEADS);
598 			Decimal("beginning sector", tsec, tmp, NO_TRACK_SECTORS);
599 			partp->dp_scyl = DOSCYL(tcyl);
600 			partp->dp_ssect = DOSSECT(tsec,tcyl);
601 			partp->dp_shd = thd;
602 
603 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
604 			thd = partp->dp_ehd;
605 			tsec = DPSECT(partp->dp_esect);
606 			Decimal("ending cylinder", tcyl, tmp, NO_TRACK_CYLINDERS);
607 			Decimal("ending head", thd, tmp, NO_TRACK_HEADS);
608 			Decimal("ending sector", tsec, tmp, NO_TRACK_SECTORS);
609 			partp->dp_ecyl = DOSCYL(tcyl);
610 			partp->dp_esect = DOSSECT(tsec,tcyl);
611 			partp->dp_ehd = thd;
612 		} else
613 			dos(partp);
614 
615 		print_part(partp);
616 	} while (!ok("Are we happy with this entry?"));
617     }
618 }
619 
620 static void
621 print_params()
622 {
623 	printf("parameters extracted from in-core disklabel are:\n");
624 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
625 			,cyls,heads,sectors,cylsecs);
626 	if (dos_cyls > 1023 || dos_heads > 255 || dos_sectors > 63)
627 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
628 	printf("parameters to be used for BIOS calculations are:\n");
629 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
630 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
631 }
632 
633 static void
634 change_active(int which)
635 {
636 	struct dos_partition *partp = &mboot.parts[0];
637 	int active, i, new, tmp;
638 
639 	active = -1;
640 	for (i = 0; i < NDOSPART; i++) {
641 		if ((partp[i].dp_flag & ACTIVE) == 0)
642 			continue;
643 		printf("Partition %d is marked active\n", i + 1);
644 		if (active == -1)
645 			active = i + 1;
646 	}
647 	if (a_flag && which != -1)
648 		active = which;
649 	else if (active == -1)
650 		active = 1;
651 
652 	if (!ok("Do you want to change the active partition?"))
653 		return;
654 setactive:
655 	do {
656 		new = active;
657 		Decimal("active partition", new, tmp, 0);
658 		if (new < 1 || new > 4) {
659 			printf("Active partition number must be in range 1-4."
660 					"  Try again.\n");
661 			goto setactive;
662 		}
663 		active = new;
664 	} while (!ok("Are you happy with this choice"));
665 	for (i = 0; i < NDOSPART; i++)
666 		partp[i].dp_flag = 0;
667 	if (active > 0 && active <= NDOSPART)
668 		partp[active-1].dp_flag = ACTIVE;
669 }
670 
671 static void
672 change_code()
673 {
674 	if (ok("Do you want to change the boot code?"))
675 		init_boot();
676 }
677 
678 void
679 get_params_to_use()
680 {
681 	int	tmp;
682 	print_params();
683 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
684 	{
685 		do
686 		{
687 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp, 0);
688 			Decimal("BIOS's idea of #heads", dos_heads, tmp, 0);
689 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp, 0);
690 			dos_cylsecs = dos_heads * dos_sectors;
691 			print_params();
692 		}
693 		while(!ok("Are you happy with this choice"));
694 	}
695 }
696 
697 
698 /***********************************************\
699 * Change real numbers into strange dos numbers	*
700 \***********************************************/
701 static void
702 dos(struct dos_partition *partp)
703 {
704 	int cy, sec;
705 	u_int32_t end;
706 
707 	if (partp->dp_typ == 0 && partp->dp_start == 0 && partp->dp_size == 0) {
708 		memcpy(partp, &mtpart, sizeof(*partp));
709 		return;
710 	}
711 
712 	/* Start c/h/s. */
713 	partp->dp_shd = partp->dp_start % dos_cylsecs / dos_sectors;
714 	cy = partp->dp_start / dos_cylsecs;
715 	sec = partp->dp_start % dos_sectors + 1;
716 	partp->dp_scyl = DOSCYL(cy);
717 	partp->dp_ssect = DOSSECT(sec, cy);
718 
719 	/* End c/h/s. */
720 	end = partp->dp_start + partp->dp_size - 1;
721 	partp->dp_ehd = end % dos_cylsecs / dos_sectors;
722 	cy = end / dos_cylsecs;
723 	sec = end % dos_sectors + 1;
724 	partp->dp_ecyl = DOSCYL(cy);
725 	partp->dp_esect = DOSSECT(sec, cy);
726 }
727 
728 static int
729 open_disk(int flag)
730 {
731 	int rwmode;
732 
733 	/* Write mode if one of these flags are set. */
734 	rwmode = (a_flag || I_flag || B_flag || flag);
735 	fd = g_open(disk, rwmode);
736 	/* If the mode fails, try read-only if we didn't. */
737 	if (fd == -1 && errno == EPERM && rwmode)
738 		fd = g_open(disk, 0);
739 	if (fd == -1 && errno == ENXIO)
740 		return -2;
741 	if (fd == -1) {
742 		warnx("can't open device %s", disk);
743 		return -1;
744 	}
745 	if (get_params() == -1) {
746 		warnx("can't get disk parameters on %s", disk);
747 		return -1;
748 	}
749 	return fd;
750 }
751 
752 static ssize_t
753 read_disk(off_t sector, void *buf)
754 {
755 
756 	lseek(fd, (sector * 512), 0);
757 	if (secsize == 0)
758 		for (secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE;
759 		     secsize *= 2) {
760 			/* try the read */
761 			int size = read(fd, buf, secsize);
762 			if (size == secsize)
763 				/* it worked so return */
764 				return secsize;
765 		}
766 	else
767 		return read(fd, buf, secsize);
768 
769 	/* we failed to read at any of the sizes */
770 	return -1;
771 }
772 
773 static int
774 geom_class_available(const char *name)
775 {
776 	struct gclass *class;
777 	struct gmesh mesh;
778 	int error;
779 
780 	error = geom_gettree(&mesh);
781 	if (error != 0)
782 		errc(1, error, "Cannot get GEOM tree");
783 
784 	LIST_FOREACH(class, &mesh.lg_class, lg_class) {
785 		if (strcmp(class->lg_name, name) == 0) {
786 			geom_deletetree(&mesh);
787 			return (1);
788 		}
789 	}
790 
791 	geom_deletetree(&mesh);
792 
793 	return (0);
794 }
795 
796 static int
797 write_disk(off_t sector, void *buf)
798 {
799 	struct gctl_req *grq;
800 	const char *errmsg;
801 	char *pname;
802 	int error;
803 
804 	/* Check that GEOM_MBR is available */
805 	if (geom_class_available("MBR") != 0) {
806 		grq = gctl_get_handle();
807 		gctl_ro_param(grq, "verb", -1, "write MBR");
808 		gctl_ro_param(grq, "class", -1, "MBR");
809 		pname = g_providername(fd);
810 		if (pname == NULL) {
811 			warn("Error getting providername for %s", disk);
812 			return (-1);
813 		}
814 		gctl_ro_param(grq, "geom", -1, pname);
815 		gctl_ro_param(grq, "data", secsize, buf);
816 		errmsg = gctl_issue(grq);
817 		free(pname);
818 		if (errmsg == NULL) {
819 			gctl_free(grq);
820 			return(0);
821 		}
822 		if (!q_flag)
823 			warnx("GEOM_MBR: %s", errmsg);
824 		gctl_free(grq);
825 	} else {
826 		/*
827 		 * Try to write MBR directly. This may help when disk
828 		 * is not in use.
829 		 * XXX: hardcoded sectorsize
830 		 */
831 		error = pwrite(fd, buf, secsize, (sector * 512));
832 		if (error == secsize)
833 			return (0);
834 	}
835 
836 	/*
837 	 * GEOM_MBR is not available or failed to write MBR.
838 	 * Now check that we have GEOM_PART and recommend to use gpart (8).
839 	 */
840 	if (geom_class_available("PART") != 0)
841 		warnx("Failed to write MBR. Try to use gpart(8).");
842 	else
843 		warnx("Failed to write sector zero");
844 	return(EINVAL);
845 }
846 
847 static int
848 get_params()
849 {
850 	int error;
851 	u_int u;
852 	off_t o;
853 
854 	error = ioctl(fd, DIOCGFWSECTORS, &u);
855 	if (error == 0)
856 		sectors = dos_sectors = u;
857 	else
858 		sectors = dos_sectors = 63;
859 
860 	error = ioctl(fd, DIOCGFWHEADS, &u);
861 	if (error == 0)
862 		heads = dos_heads = u;
863 	else
864 		heads = dos_heads = 255;
865 
866 	dos_cylsecs = cylsecs = heads * sectors;
867 	disksecs = cyls * heads * sectors;
868 
869 	u = g_sectorsize(fd);
870 	if (u <= 0)
871 		return (-1);
872 
873 	o = g_mediasize(fd);
874 	if (o < 0)
875 		return (-1);
876 	disksecs = o / u;
877 	cyls = dos_cyls = o / (u * dos_heads * dos_sectors);
878 
879 	return (disksecs);
880 }
881 
882 static int
883 read_s0()
884 {
885 	int i;
886 
887 	mboot.bootinst_size = secsize;
888 	if (mboot.bootinst != NULL)
889 		free(mboot.bootinst);
890 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
891 		warnx("unable to allocate buffer to read fdisk "
892 		      "partition table");
893 		return -1;
894 	}
895 	if (read_disk(0, mboot.bootinst) == -1) {
896 		warnx("can't read fdisk partition table");
897 		return -1;
898 	}
899 	if (le16dec(&mboot.bootinst[DOSMAGICOFFSET]) != DOSMAGIC) {
900 		warnx("invalid fdisk partition table found");
901 		/* So should we initialize things */
902 		return -1;
903 	}
904 	for (i = 0; i < NDOSPART; i++)
905 		dos_partition_dec(
906 		    &mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
907 		    &mboot.parts[i]);
908 	return 0;
909 }
910 
911 static int
912 write_s0()
913 {
914 	int	sector, i;
915 
916 	if (iotest) {
917 		print_s0();
918 		return 0;
919 	}
920 	for(i = 0; i < NDOSPART; i++)
921 		dos_partition_enc(&mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
922 		    &mboot.parts[i]);
923 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
924 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
925 		if (write_disk(sector,
926 			       &mboot.bootinst[sector * secsize]) == -1) {
927 			warn("can't write fdisk partition table");
928 			return -1;
929 		}
930 	return(0);
931 }
932 
933 
934 static int
935 ok(const char *str)
936 {
937 	printf("%s [n] ", str);
938 	fflush(stdout);
939 	if (fgets(lbuf, LBUF, stdin) == NULL)
940 		exit(1);
941 	lbuf[strlen(lbuf)-1] = 0;
942 
943 	if (*lbuf &&
944 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
945 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
946 		return 1;
947 	else
948 		return 0;
949 }
950 
951 static int
952 decimal(const char *str, int *num, int deflt, uint32_t maxval)
953 {
954 	long long acc;
955 	int c;
956 	char *cp;
957 
958 	while (1) {
959 		acc = 0;
960 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
961 		fflush(stdout);
962 		if (fgets(lbuf, LBUF, stdin) == NULL)
963 			exit(1);
964 		lbuf[strlen(lbuf)-1] = 0;
965 
966 		if (!*lbuf)
967 			return 0;
968 
969 		cp = lbuf;
970 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
971 		if (!c)
972 			return 0;
973 		while ((c = *cp++)) {
974 			if (c <= '9' && c >= '0') {
975 				if (acc <= maxval || maxval == 0)
976 					acc = acc * 10 + c - '0';
977 			} else
978 				break;
979 		}
980 		if (c == ' ' || c == '\t')
981 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
982 		if (!c) {
983 			if (maxval > 0 && acc > maxval) {
984 				acc = maxval;
985 				printf("%s exceeds maximum value allowed for "
986 				  "this field. The value has been reduced "
987 				  "to %lld\n", lbuf, acc);
988 			}
989 			*num = acc;
990 			return 1;
991 		} else
992 			printf("%s is an invalid decimal number.  Try again.\n",
993 				lbuf);
994 	}
995 }
996 
997 
998 static void
999 parse_config_line(char *line, CMD *command)
1000 {
1001     char	*cp, *end;
1002 
1003     cp = line;
1004     while (1) {
1005 	memset(command, 0, sizeof(*command));
1006 
1007 	while (isspace(*cp)) ++cp;
1008 	if (*cp == '\0' || *cp == '#')
1009 	    break;
1010 	command->cmd = *cp++;
1011 
1012 	/*
1013 	 * Parse args
1014 	 */
1015 	    while (1) {
1016 	    while (isspace(*cp)) ++cp;
1017 	    if (*cp == '\0')
1018 		break;		/* eol */
1019 	    if (*cp == '#')
1020 		break;		/* found comment */
1021 	    if (isalpha(*cp))
1022 		command->args[command->n_args].argtype = *cp++;
1023 	    end = NULL;
1024 	    command->args[command->n_args].arg_val = strtoul(cp, &end, 0);
1025  	    if (cp == end || (!isspace(*end) && *end != '\0')) {
1026  		char ch;
1027  		end = cp;
1028  		while (!isspace(*end) && *end != '\0') ++end;
1029  		ch = *end; *end = '\0';
1030  		command->args[command->n_args].arg_str = strdup(cp);
1031  		*end = ch;
1032  	    } else
1033  		command->args[command->n_args].arg_str = NULL;
1034 	    cp = end;
1035 	    command->n_args++;
1036 	}
1037 	break;
1038     }
1039 }
1040 
1041 
1042 static int
1043 process_geometry(CMD *command)
1044 {
1045     int		status = 1, i;
1046 
1047     while (1) {
1048 	geom_processed = 1;
1049 	    if (part_processed) {
1050 	    warnx(
1051 	"ERROR line %d: the geometry specification line must occur before\n\
1052     all partition specifications",
1053 		    current_line_number);
1054 	    status = 0;
1055 	    break;
1056 	}
1057 	    if (command->n_args != 3) {
1058 	    warnx("ERROR line %d: incorrect number of geometry args",
1059 		    current_line_number);
1060 	    status = 0;
1061 	    break;
1062 	}
1063 	    dos_cyls = 0;
1064 	    dos_heads = 0;
1065 	    dos_sectors = 0;
1066 	    for (i = 0; i < 3; ++i) {
1067 		    switch (command->args[i].argtype) {
1068 	    case 'c':
1069 		dos_cyls = command->args[i].arg_val;
1070 		break;
1071 	    case 'h':
1072 		dos_heads = command->args[i].arg_val;
1073 		break;
1074 	    case 's':
1075 		dos_sectors = command->args[i].arg_val;
1076 		break;
1077 	    default:
1078 		warnx(
1079 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1080 			current_line_number, command->args[i].argtype,
1081 			command->args[i].argtype);
1082 		status = 0;
1083 		break;
1084 	    }
1085 	}
1086 	if (status == 0)
1087 	    break;
1088 
1089 	dos_cylsecs = dos_heads * dos_sectors;
1090 
1091 	/*
1092 	 * Do sanity checks on parameter values
1093 	 */
1094 	    if (dos_cyls == 0) {
1095 	    warnx("ERROR line %d: number of cylinders not specified",
1096 		    current_line_number);
1097 	    status = 0;
1098 	}
1099 	    if (dos_cyls > 1024) {
1100 	    warnx(
1101 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1102     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1103     is dedicated to FreeBSD)",
1104 		    current_line_number, dos_cyls);
1105 	}
1106 
1107 	    if (dos_heads == 0) {
1108 	    warnx("ERROR line %d: number of heads not specified",
1109 		    current_line_number);
1110 	    status = 0;
1111 	    } else if (dos_heads > 256) {
1112 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1113 		    current_line_number);
1114 	    status = 0;
1115 	}
1116 
1117 	    if (dos_sectors == 0) {
1118 	    warnx("ERROR line %d: number of sectors not specified",
1119 		    current_line_number);
1120 	    status = 0;
1121 	    } else if (dos_sectors > 63) {
1122 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1123 		    current_line_number);
1124 	    status = 0;
1125 	}
1126 
1127 	break;
1128     }
1129     return (status);
1130 }
1131 
1132 static u_int32_t
1133 str2sectors(const char *str)
1134 {
1135 	char *end;
1136 	unsigned long val;
1137 
1138 	val = strtoul(str, &end, 0);
1139 	if (str == end || *end == '\0') {
1140 		warnx("ERROR line %d: unexpected size: \'%s\'",
1141 		    current_line_number, str);
1142 		return NO_DISK_SECTORS;
1143 	}
1144 
1145 	if (*end == 'K')
1146 		val *= 1024UL / secsize;
1147 	else if (*end == 'M')
1148 		val *= 1024UL * 1024UL / secsize;
1149 	else if (*end == 'G')
1150 		val *= 1024UL * 1024UL * 1024UL / secsize;
1151 	else {
1152 		warnx("ERROR line %d: unexpected modifier: %c "
1153 		    "(not K/M/G)", current_line_number, *end);
1154 		return NO_DISK_SECTORS;
1155 	}
1156 
1157 	return val;
1158 }
1159 
1160 static int
1161 process_partition(CMD *command)
1162 {
1163     int				status = 0, partition;
1164     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1165     u_int32_t			adj_size, max_end;
1166     struct dos_partition	*partp;
1167 
1168 	while (1) {
1169 	part_processed = 1;
1170 		if (command->n_args != 4) {
1171 	    warnx("ERROR line %d: incorrect number of partition args",
1172 		    current_line_number);
1173 	    break;
1174 	}
1175 	partition = command->args[0].arg_val;
1176 		if (partition < 1 || partition > 4) {
1177 	    warnx("ERROR line %d: invalid partition number %d",
1178 		    current_line_number, partition);
1179 	    break;
1180 	}
1181 	partp = &mboot.parts[partition - 1];
1182 	bzero(partp, sizeof (*partp));
1183 	partp->dp_typ = command->args[1].arg_val;
1184 	if (command->args[2].arg_str != NULL) {
1185 		if (strcmp(command->args[2].arg_str, "*") == 0) {
1186 			int i;
1187 			partp->dp_start = dos_sectors;
1188 			for (i = 1; i < partition; i++) {
1189     				struct dos_partition *prev_partp;
1190 				prev_partp = ((struct dos_partition *)
1191 				    &mboot.parts) + i - 1;
1192 				if (prev_partp->dp_typ != 0)
1193 					partp->dp_start = prev_partp->dp_start +
1194 					    prev_partp->dp_size;
1195 			}
1196 			if (partp->dp_start % dos_sectors != 0) {
1197 		    		prev_head_boundary = partp->dp_start /
1198 				    dos_sectors * dos_sectors;
1199 		    		partp->dp_start = prev_head_boundary +
1200 				    dos_sectors;
1201 			}
1202 		} else {
1203 			partp->dp_start = str2sectors(command->args[2].arg_str);
1204 			if (partp->dp_start == NO_DISK_SECTORS)
1205 				break;
1206 		}
1207 	} else
1208 		partp->dp_start = command->args[2].arg_val;
1209 
1210 	if (command->args[3].arg_str != NULL) {
1211 		if (strcmp(command->args[3].arg_str, "*") == 0)
1212 			partp->dp_size = ((disksecs / dos_cylsecs) *
1213 			    dos_cylsecs) - partp->dp_start;
1214 		else {
1215 			partp->dp_size = str2sectors(command->args[3].arg_str);
1216 			if (partp->dp_size == NO_DISK_SECTORS)
1217 				break;
1218 		}
1219 		prev_cyl_boundary = ((partp->dp_start + partp->dp_size) /
1220 		    dos_cylsecs) * dos_cylsecs;
1221 		if (prev_cyl_boundary > partp->dp_start)
1222 			partp->dp_size = prev_cyl_boundary - partp->dp_start;
1223 	} else
1224 		partp->dp_size = command->args[3].arg_val;
1225 
1226 	max_end = partp->dp_start + partp->dp_size;
1227 
1228 	if (partp->dp_typ == 0) {
1229 	    /*
1230 	     * Get out, the partition is marked as unused.
1231 	     */
1232 	    /*
1233 	     * Insure that it's unused.
1234 	     */
1235 	    bzero(partp, sizeof(*partp));
1236 	    status = 1;
1237 	    break;
1238 	}
1239 
1240 	/*
1241 	 * Adjust start upwards, if necessary, to fall on a head boundary.
1242 	 */
1243 		if (partp->dp_start % dos_sectors != 0) {
1244 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1245 	    if (max_end < dos_sectors ||
1246 			    prev_head_boundary > max_end - dos_sectors) {
1247 		/*
1248 		 * Can't go past end of partition
1249 		 */
1250 		warnx(
1251 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1252     a head boundary",
1253 			current_line_number, partition);
1254 		break;
1255 	    }
1256 	    warnx(
1257 	"WARNING: adjusting start offset of partition %d\n\
1258     from %u to %u, to fall on a head boundary",
1259 		    partition, (u_int)partp->dp_start,
1260 		    (u_int)(prev_head_boundary + dos_sectors));
1261 	    partp->dp_start = prev_head_boundary + dos_sectors;
1262 	}
1263 
1264 	/*
1265 	 * Adjust size downwards, if necessary, to fall on a cylinder
1266 	 * boundary.
1267 	 */
1268 	prev_cyl_boundary =
1269 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1270 	if (prev_cyl_boundary > partp->dp_start)
1271 	    adj_size = prev_cyl_boundary - partp->dp_start;
1272 		else {
1273 	    warnx(
1274 	"ERROR: could not adjust partition to start on a head boundary\n\
1275     and end on a cylinder boundary.");
1276 	    return (0);
1277 	}
1278 		if (adj_size != partp->dp_size) {
1279 	    warnx(
1280 	"WARNING: adjusting size of partition %d from %u to %u\n\
1281     to end on a cylinder boundary",
1282 		    partition, (u_int)partp->dp_size, (u_int)adj_size);
1283 	    partp->dp_size = adj_size;
1284 	}
1285 		if (partp->dp_size == 0) {
1286 	    warnx("ERROR line %d: size of partition %d is zero",
1287 		    current_line_number, partition);
1288 	    break;
1289 	}
1290 
1291 	dos(partp);
1292 	status = 1;
1293 	break;
1294     }
1295     return (status);
1296 }
1297 
1298 
1299 static int
1300 process_active(CMD *command)
1301 {
1302     int				status = 0, partition, i;
1303     struct dos_partition	*partp;
1304 
1305 	while (1) {
1306 	active_processed = 1;
1307 		if (command->n_args != 1) {
1308 	    warnx("ERROR line %d: incorrect number of active args",
1309 		    current_line_number);
1310 	    status = 0;
1311 	    break;
1312 	}
1313 	partition = command->args[0].arg_val;
1314 		if (partition < 1 || partition > 4) {
1315 	    warnx("ERROR line %d: invalid partition number %d",
1316 		    current_line_number, partition);
1317 	    break;
1318 	}
1319 	/*
1320 	 * Reset active partition
1321 	 */
1322 	partp = mboot.parts;
1323 	for (i = 0; i < NDOSPART; i++)
1324 	    partp[i].dp_flag = 0;
1325 	partp[partition-1].dp_flag = ACTIVE;
1326 
1327 	status = 1;
1328 	break;
1329     }
1330     return (status);
1331 }
1332 
1333 
1334 static int
1335 process_line(char *line)
1336 {
1337     CMD		command;
1338     int		status = 1;
1339 
1340 	while (1) {
1341 	parse_config_line(line, &command);
1342 		switch (command.cmd) {
1343 	case 0:
1344 	    /*
1345 	     * Comment or blank line
1346 	     */
1347 	    break;
1348 	case 'g':
1349 	    /*
1350 	     * Set geometry
1351 	     */
1352 	    status = process_geometry(&command);
1353 	    break;
1354 	case 'p':
1355 	    status = process_partition(&command);
1356 	    break;
1357 	case 'a':
1358 	    status = process_active(&command);
1359 	    break;
1360 	default:
1361 	    status = 0;
1362 	    break;
1363 	}
1364 	break;
1365     }
1366     return (status);
1367 }
1368 
1369 
1370 static int
1371 read_config(char *config_file)
1372 {
1373     FILE	*fp = NULL;
1374     int		status = 1;
1375     char	buf[1010];
1376 
1377 	while (1) {
1378 		if (strcmp(config_file, "-") != 0) {
1379 	    /*
1380 	     * We're not reading from stdin
1381 	     */
1382 			if ((fp = fopen(config_file, "r")) == NULL) {
1383 		status = 0;
1384 		break;
1385 	    }
1386 		} else {
1387 	    fp = stdin;
1388 	}
1389 	current_line_number = 0;
1390 		while (!feof(fp)) {
1391 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1392 		break;
1393 	    ++current_line_number;
1394 	    status = process_line(buf);
1395 	    if (status == 0)
1396 		break;
1397 	    }
1398 	break;
1399     }
1400 	if (fp) {
1401 	/*
1402 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1403 	 */
1404 	fclose(fp);
1405     }
1406     return (status);
1407 }
1408 
1409 
1410 static void
1411 reset_boot(void)
1412 {
1413     int				i;
1414     struct dos_partition	*partp;
1415 
1416     init_boot();
1417     for (i = 0; i < 4; ++i) {
1418 	partp = &mboot.parts[i];
1419 	bzero(partp, sizeof(*partp));
1420     }
1421 }
1422 
1423 static int
1424 sanitize_partition(struct dos_partition *partp)
1425 {
1426     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1427     u_int32_t			max_end, size, start;
1428 
1429     start = partp->dp_start;
1430     size = partp->dp_size;
1431     max_end = start + size;
1432     /* Only allow a zero size if the partition is being marked unused. */
1433     if (size == 0) {
1434 	if (start == 0 && partp->dp_typ == 0)
1435 	    return (1);
1436 	warnx("ERROR: size of partition is zero");
1437 	return (0);
1438     }
1439     /* Return if no adjustment is necessary. */
1440     if (start % dos_sectors == 0 && (start + size) % dos_sectors == 0)
1441 	return (1);
1442 
1443     if (start == 0) {
1444 	    warnx("WARNING: partition overlaps with partition table");
1445 	    if (ok("Correct this automatically?"))
1446 		    start = dos_sectors;
1447     }
1448     if (start % dos_sectors != 0)
1449 	warnx("WARNING: partition does not start on a head boundary");
1450     if ((start  +size) % dos_sectors != 0)
1451 	warnx("WARNING: partition does not end on a cylinder boundary");
1452     warnx("WARNING: this may confuse the BIOS or some operating systems");
1453     if (!ok("Correct this automatically?"))
1454 	return (1);
1455 
1456     /*
1457      * Adjust start upwards, if necessary, to fall on a head boundary.
1458      */
1459     if (start % dos_sectors != 0) {
1460 	prev_head_boundary = start / dos_sectors * dos_sectors;
1461 	if (max_end < dos_sectors ||
1462 	    prev_head_boundary >= max_end - dos_sectors) {
1463 	    /*
1464 	     * Can't go past end of partition
1465 	     */
1466 	    warnx(
1467     "ERROR: unable to adjust start of partition to fall on a head boundary");
1468 	    return (0);
1469         }
1470 	start = prev_head_boundary + dos_sectors;
1471     }
1472 
1473     /*
1474      * Adjust size downwards, if necessary, to fall on a cylinder
1475      * boundary.
1476      */
1477     prev_cyl_boundary = ((start + size) / dos_cylsecs) * dos_cylsecs;
1478     if (prev_cyl_boundary > start)
1479 	size = prev_cyl_boundary - start;
1480     else {
1481 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1482     and end on a cylinder boundary.");
1483 	return (0);
1484     }
1485 
1486     /* Finally, commit any changes to partp and return. */
1487     if (start != partp->dp_start) {
1488 	warnx("WARNING: adjusting start offset of partition to %u",
1489 	    (u_int)start);
1490 	partp->dp_start = start;
1491     }
1492     if (size != partp->dp_size) {
1493 	warnx("WARNING: adjusting size of partition to %u", (u_int)size);
1494 	partp->dp_size = size;
1495     }
1496 
1497     return (1);
1498 }
1499 
1500 /*
1501  * Try figuring out the root device's canonical disk name.
1502  * The following choices are considered:
1503  *   /dev/ad0s1a     => /dev/ad0
1504  *   /dev/da0a       => /dev/da0
1505  *   /dev/vinum/root => /dev/vinum/root
1506  * A ".eli" part is removed if it exists (see geli(8)).
1507  * A ".journal" ending is removed if it exists (see gjournal(8)).
1508  */
1509 static char *
1510 get_rootdisk(void)
1511 {
1512 	struct statfs rootfs;
1513 	regex_t re;
1514 #define NMATCHES 2
1515 	regmatch_t rm[NMATCHES];
1516 	char dev[PATH_MAX], *s;
1517 	int rv;
1518 
1519 	if (statfs("/", &rootfs) == -1)
1520 		err(1, "statfs(\"/\")");
1521 
1522 	if ((rv = regcomp(&re, "^(/dev/[a-z/]+[0-9]*)([sp][0-9]+)?[a-h]?(\\.journal)?$",
1523 		    REG_EXTENDED)) != 0)
1524 		errx(1, "regcomp() failed (%d)", rv);
1525 	strlcpy(dev, rootfs.f_mntfromname, sizeof (dev));
1526 	if ((s = strstr(dev, ".eli")) != NULL)
1527 	    memmove(s, s+4, strlen(s + 4) + 1);
1528 
1529 	if ((rv = regexec(&re, dev, NMATCHES, rm, 0)) != 0)
1530 		errx(1,
1531 "mounted root fs resource doesn't match expectations (regexec returned %d)",
1532 		    rv);
1533 	if ((s = malloc(rm[1].rm_eo - rm[1].rm_so + 1)) == NULL)
1534 		errx(1, "out of memory");
1535 	memcpy(s, rootfs.f_mntfromname + rm[1].rm_so,
1536 	    rm[1].rm_eo - rm[1].rm_so);
1537 	s[rm[1].rm_eo - rm[1].rm_so] = 0;
1538 
1539 	return s;
1540 }
1541