xref: /dragonfly/sbin/fdisk/fdisk.c (revision 5062ee70)
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  * $FreeBSD: /repoman/r/ncvs/src/sbin/i386/fdisk/fdisk.c,v 1.36.2.14 2004/01/30 14:40:47 harti Exp $
27  */
28 
29 #include <sys/param.h>
30 #include <sys/diskslice.h>
31 #include <sys/diskmbr.h>
32 #include <sys/ioctl_compat.h>
33 #include <sys/sysctl.h>
34 #include <sys/stat.h>
35 #include <ctype.h>
36 #include <fcntl.h>
37 #include <err.h>
38 #include <fstab.h>
39 #include <errno.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 #define LBUF 100
46 static char lbuf[LBUF];
47 
48 /*
49  *
50  * Ported to 386bsd by Julian Elischer  Thu Oct 15 20:26:46 PDT 1992
51  *
52  * 14-Dec-89  Robert Baron (rvb) at Carnegie-Mellon University
53  *	Copyright (c) 1989	Robert. V. Baron
54  *	Created.
55  */
56 
57 #define Decimal(str, ans, tmp) if (decimal(str, &tmp, ans)) ans = tmp
58 #define MAX_SEC_SIZE 2048		/* maximum section size that is supported */
59 #define MIN_SEC_SIZE 512		/* the sector size to start sensing at */
60 #define MAX_SECTORS_PER_TRACK 0x3f	/* maximum number of sectors per track */
61 #define MIN_SECTORS_PER_TRACK 0x1	/* minimum number of sectors per track */
62 #define MAX_HEADS 0xff			/* maximum number of head */
63 static int secsize = 0;		/* the sensed sector size */
64 
65 static int fd;				/* file descriptor of the given disk */
66 static const char *disk;
67 static const char *disks[] =
68 {
69   "/dev/ad0", "/dev/da0", "/dev/vkd0", 0
70 };
71 
72 static int cyls, sectors, heads, cylsecs;
73 static int64_t disksecs;
74 
75 struct mboot
76 {
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[4];
81 };
82 static struct mboot mboot;
83 
84 #define ACTIVE 0x80
85 #define BOOT_MAGIC 0xAA55
86 
87 int dos_cyls;
88 int dos_heads;
89 int dos_sectors;
90 int dos_cylsecs;
91 
92 #define DOSSECT(s,c) ((s & MAX_SECTORS_PER_TRACK) | ((c >> 2) & 0xc0))
93 #define DOSCYL(c)	(c & 0xff)
94 #define MAXCYL		1023
95 static int partition = -1;
96 
97 #define MAX_ARGS	10
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 	long long arg_val;
110     }			args[MAX_ARGS];
111 } CMD;
112 
113 static int B_flag  = 0;		/* replace boot code */
114 static int C_flag  = 0;		/* use wrapped values for CHS */
115 static int E_flag  = 0;		/* Erase through TRIM */
116 static int I_flag  = 0;		/* use entire disk for DragonFly */
117 static int a_flag  = 0;		/* set active partition */
118 static char *b_flag = NULL;	/* path to boot code */
119 static int i_flag  = 0;		/* replace partition data */
120 static int u_flag  = 0;		/* update partition data */
121 static int p_flag  = 0;		/* operate on a disk image file */
122 static int s_flag  = 0;		/* Print a summary and exit */
123 static int t_flag  = 0;		/* test only */
124 static char *f_flag = NULL;	/* Read config info from file */
125 static int v_flag  = 0;		/* Be verbose */
126 
127 struct part_type
128 {
129  unsigned char type;
130  const char *name;
131 }part_types[] =
132 {
133 	 {0x00, "unused"}
134 	,{0x01, "Primary DOS with 12 bit FAT"}
135 	,{0x02, "XENIX / filesystem"}
136 	,{0x03, "XENIX /usr filesystem"}
137 	,{0x04, "Primary DOS with 16 bit FAT (<= 32MB)"}
138 	,{0x05, "Extended DOS"}
139 	,{0x06, "Primary 'big' DOS (> 32MB)"}
140 	,{0x07, "OS/2 HPFS, NTFS, QNX-2 (16 bit) or Advanced UNIX"}
141 	,{0x08, "AIX filesystem"}
142 	,{0x09, "AIX boot partition or Coherent"}
143 	,{0x0A, "OS/2 Boot Manager or OPUS"}
144 	,{0x0B, "DOS or Windows 95 with 32 bit FAT"}
145 	,{0x0C, "DOS or Windows 95 with 32 bit FAT, LBA"}
146 	,{0x0E, "Primary 'big' DOS (> 32MB, LBA)"}
147 	,{0x0F, "Extended DOS, LBA"}
148 	,{0x10, "OPUS"}
149 	,{0x11, "OS/2 BM: hidden DOS with 12-bit FAT"}
150 	,{0x12, "Compaq diagnostics"}
151 	,{0x14, "OS/2 BM: hidden DOS with 16-bit FAT (< 32MB)"}
152 	,{0x16, "OS/2 BM: hidden DOS with 16-bit FAT (>= 32MB)"}
153 	,{0x17, "OS/2 BM: hidden IFS (e.g. HPFS)"}
154 	,{0x18, "AST Windows swapfile"}
155 	,{0x24, "NEC DOS"}
156 	,{0x39, "plan9"}
157 	,{0x3C, "PartitionMagic recovery"}
158 	,{0x40, "VENIX 286"}
159 	,{0x41, "Linux/MINIX (sharing disk with DRDOS)"}
160 	,{0x42, "SFS or Linux swap (sharing disk with DRDOS)"}
161 	,{0x43, "Linux native (sharing disk with DRDOS)"}
162 	,{0x4D, "QNX 4.2 Primary"}
163 	,{0x4E, "QNX 4.2 Secondary"}
164 	,{0x4F, "QNX 4.2 Tertiary"}
165 	,{0x50, "DM"}
166 	,{0x51, "DM"}
167 	,{0x52, "CP/M or Microport SysV/AT"}
168 	,{0x53, "DM6 Aux3"}
169 	,{0x54, "DM6"}
170 	,{0x55, "EZ-Drive (disk manager)"}
171 	,{0x56, "GB"}
172 	,{0x5C, "Priam Edisk (disk manager)"} /* according to S. Widlake */
173 	,{0x61, "Speed"}
174 	,{0x63, "ISC UNIX, other System V/386, GNU HURD or Mach"}
175 	,{0x64, "Novell Netware 2.xx"}
176 	,{0x65, "Novell Netware 3.xx"}
177 	,{0x6C, "DragonFlyBSD"}
178 	,{0x70, "DiskSecure Multi-Boot"}
179 	,{0x75, "PCIX"}
180 	,{0x77, "QNX4.x"}
181 	,{0x78, "QNX4.x 2nd part"}
182 	,{0x79, "QNX4.x 3rd part"}
183 	,{0x80, "Minix 1.1 ... 1.4a"}
184 	,{0x81, "Minix 1.4b ... 1.5.10"}
185 	,{0x82, "Linux swap or Solaris x86"}
186 	,{0x83, "Linux filesystem"}
187 	,{0x84, "OS/2 hidden C: drive"}
188 	,{0x85, "Linux extended"}
189 	,{0x86, "NTFS volume set??"}
190 	,{0x87, "NTFS volume set??"}
191 	,{0x93, "Amoeba filesystem"}
192 	,{0x94, "Amoeba bad block table"}
193 	,{0x9F, "BSD/OS"}
194 	,{0xA0, "Suspend to Disk"}
195 	,{0xA5, "DragonFly/FreeBSD/NetBSD/386BSD"}
196 	,{0xA6, "OpenBSD"}
197 	,{0xA7, "NEXTSTEP"}
198 	,{0xA9, "NetBSD"}
199 	,{0xAC, "IBM JFS"}
200 	,{0xB7, "BSDI BSD/386 filesystem"}
201 	,{0xB8, "BSDI BSD/386 swap"}
202 	,{0xBE, "Solaris x86 boot"}
203 	,{0xC1, "DRDOS/sec with 12-bit FAT"}
204 	,{0xC4, "DRDOS/sec with 16-bit FAT (< 32MB)"}
205 	,{0xC6, "DRDOS/sec with 16-bit FAT (>= 32MB)"}
206 	,{0xC7, "Syrinx"}
207 	,{0xDB, "Concurrent CPM or C.DOS or CTOS"}
208 	,{0xE1, "Speed"}
209 	,{0xE3, "Speed"}
210 	,{0xE4, "Speed"}
211 	,{0xEB, "BeOS file system"}
212 	,{0xEE, "EFI GPT"}
213 	,{0xEF, "EFI System Partition"}
214 	,{0xF1, "Speed"}
215 	,{0xF2, "DOS 3.3+ Secondary"}
216 	,{0xF4, "Speed"}
217 	,{0xFE, "SpeedStor >1024 cyl. or LANstep"}
218 	,{0xFF, "BBT (Bad Blocks Table)"}
219 };
220 
221 static void print_s0(int which);
222 static void print_part(int i);
223 static void init_sector0(unsigned long start);
224 static void init_boot(void);
225 static void change_part(int i);
226 static void print_params(void);
227 static void change_active(int which);
228 static void change_code(void);
229 static void get_params_to_use(void);
230 static void dos(struct dos_partition *partp);
231 static int open_disk(void);
232 static void erase_partition(int i);
233 static ssize_t read_disk(off_t sector, void *buf);
234 static ssize_t write_disk(off_t sector, void *buf);
235 static int get_params(void);
236 static int read_s0(void);
237 static int write_s0(void);
238 static int ok(const char *str);
239 static int decimal(const char *str, int *num, int deflt);
240 static const char *get_type(int type);
241 static int read_config(char *config_file);
242 static void reset_boot(void);
243 static int sanitize_partition(struct dos_partition *);
244 static void usage(void);
245 
246 int
247 main(int argc, char *argv[])
248 {
249 	int	c, i;
250 
251 	while ((c = getopt(argc, argv, "BCEIab:f:p:istuv1234")) != -1)
252 		switch (c) {
253 		case 'B':
254 			B_flag = 1;
255 			break;
256 		case 'C':
257 			C_flag = 1;
258 			break;
259 		case 'E':
260 			E_flag = 1;
261 			break;
262 		case 'I':
263 			I_flag = 1;
264 			break;
265 		case 'a':
266 			a_flag = 1;
267 			break;
268 		case 'b':
269 			b_flag = optarg;
270 			break;
271 		case 'f':
272 			f_flag = optarg;
273 			break;
274 		case 'p':
275 			disk = optarg;
276 			p_flag = 1;
277 			break;
278 		case 'i':
279 			i_flag = 1;
280 			break;
281 		case 's':
282 			s_flag = 1;
283 			break;
284 		case 't':
285 			t_flag = 1;
286 			break;
287 		case 'u':
288 			u_flag = 1;
289 			break;
290 		case 'v':
291 			v_flag = 1;
292 			break;
293 		case '1':
294 		case '2':
295 		case '3':
296 		case '4':
297 			partition = c - '0';
298 			break;
299 		default:
300 			usage();
301 		}
302 	if (f_flag || i_flag)
303 		u_flag = 1;
304 	if (t_flag)
305 		v_flag = 1;
306 	argc -= optind;
307 	argv += optind;
308 
309 	if (argc > 0) {
310 		disk = getdevpath(argv[0], 0);
311 		if (open_disk() < 0)
312 			err(1, "cannot open disk %s", disk);
313 	} else if (disk == NULL) {
314 		int rv = 0;
315 
316 		for(i = 0; disks[i]; i++)
317 		{
318 			disk = disks[i];
319 			rv = open_disk();
320 			if (rv != -2) break;
321 		}
322 		if (rv < 0)
323 			err(1, "cannot open any disk");
324 	} else {
325 		if (open_disk() < 0)
326 			err(1, "cannot open disk %s", disk);
327 	}
328 
329 	/* (abu)use mboot.bootinst to probe for the sector size */
330 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
331 		err(1, "cannot allocate buffer to determine disk sector size");
332 	read_disk(0, mboot.bootinst);
333 	free(mboot.bootinst);
334 	mboot.bootinst = NULL;
335 
336 	if (s_flag)
337 	{
338 		int j;
339 		struct dos_partition *partp;
340 
341 		if (read_s0())
342 			err(1, "read_s0");
343 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
344 		    dos_sectors);
345 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
346 		for (j = 0; j < NDOSPART; j++) {
347 			partp = ((struct dos_partition *) &mboot.parts) + j;
348 			if (partp->dp_start == 0 && partp->dp_size == 0)
349 				continue;
350 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", j + 1,
351 			    (u_long) partp->dp_start,
352 			    (u_long) partp->dp_size, partp->dp_typ,
353 			    partp->dp_flag);
354 		}
355 		exit(0);
356 	}
357 
358 	printf("******* Working on device %s *******\n",disk);
359 
360 	if (I_flag)
361 	{
362 		struct dos_partition *partp;
363 
364 		read_s0();
365 		reset_boot();
366 		partp = (struct dos_partition *) (&mboot.parts[0]);
367 		partp->dp_typ = DOSPTYP_DFLYBSD;
368 		partp->dp_flag = ACTIVE;
369 		partp->dp_start = dos_sectors;
370 		if (disksecs - dos_sectors > 0xFFFFFFFFU) {
371 			printf("Warning: Ending logical block > 2TB, using max value\n");
372 			partp->dp_size = 0xFFFFFFFFU;
373 		} else {
374 			partp->dp_size = (disksecs / dos_cylsecs) *
375 					dos_cylsecs - dos_sectors;
376 		}
377 		dos(partp);
378 		if (v_flag)
379 			print_s0(-1);
380 
381 		if (E_flag) {
382 			/* Trim now if we're using the entire device */
383 			erase_partition(0);
384 		}
385 
386 		if (!t_flag)
387 			write_s0();
388 		exit(0);
389 	}
390 	if (f_flag)
391 	{
392 	    if (read_s0() || i_flag)
393 	    {
394 		reset_boot();
395 	    }
396 
397 	    if (!read_config(f_flag))
398 	    {
399 		exit(1);
400 	    }
401 	    if (v_flag)
402 	    {
403 		print_s0(-1);
404 	    }
405 	    if (!t_flag)
406 	    {
407 		write_s0();
408 	    }
409 	}
410 	else
411 	{
412 	    if (u_flag)
413 	    {
414 		get_params_to_use();
415 	    }
416 	    else
417 	    {
418 		print_params();
419 	    }
420 
421 	    if (read_s0())
422 		init_sector0(dos_sectors);
423 
424 	    printf("Media sector size is %d\n", secsize);
425 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
426 	    printf("Information from DOS bootblock is:\n");
427 	    if (partition == -1)
428 		for (i = 1; i <= NDOSPART; i++)
429 		    change_part(i);
430 	    else
431 		change_part(partition);
432 
433 	    if (u_flag || a_flag)
434 		change_active(partition);
435 
436 	    if (B_flag)
437 		change_code();
438 
439 	    if (u_flag || a_flag || B_flag) {
440 		if (!t_flag)	{
441 		    printf("\nWe haven't changed the partition table yet.  ");
442 		    printf("This is your last chance.\n");
443 		}
444 		print_s0(-1);
445 		if (!t_flag)	{
446 		    if (ok("Should we write new partition table?")) {
447 			if (E_flag && u_flag) {
448 			    /*
449 			     * Trim now because we've committed to
450 			     * updating the partition.
451 			     */
452 			    if (partition == -1)
453 			        for (i = 0; i < NDOSPART; i++)
454 			            erase_partition(i);
455 				else
456 			            erase_partition(partition);
457 			}
458 			write_s0();
459 		    }
460 		}
461 		else
462 		{
463 		    printf("\n-t flag specified -- partition table not written.\n");
464 		}
465 	    }
466 	}
467 
468 	exit(0);
469 }
470 
471 static void
472 usage(void)
473 {
474 	fprintf(stderr, "%s%s",
475 		"usage: fdisk [-BCEIaistu] [-b bootcode] [-p diskimage] [-1234] [disk]\n",
476 		"       fdisk -f configfile [-itv] [disk]\n");
477         exit(1);
478 }
479 
480 static void
481 print_s0(int which)
482 {
483 	int	i;
484 
485 	print_params();
486 	printf("Information from DOS bootblock is:\n");
487 	if (which == -1)
488 		for (i = 1; i <= NDOSPART; i++)
489 			printf("%d: ", i), print_part(i);
490 	else
491 		print_part(which);
492 }
493 
494 static struct dos_partition mtpart = { 0 };
495 
496 static void
497 print_part(int i)
498 {
499 	struct	  dos_partition *partp;
500 	uint64_t part_mb;
501 
502 	partp = ((struct dos_partition *) &mboot.parts) + i - 1;
503 
504 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
505 		printf("<UNUSED>\n");
506 		return;
507 	}
508 	/*
509 	 * Be careful not to overflow.
510 	 */
511 	part_mb = partp->dp_size;
512 	part_mb *= secsize;
513 	part_mb /= (1024 * 1024);
514 	printf("sysid %d,(%s)\n", partp->dp_typ, get_type(partp->dp_typ));
515 	printf("    start %lu, size %lu (%jd Meg), flag %x%s\n",
516 		(u_long)partp->dp_start,
517 		(u_long)partp->dp_size,
518 		(intmax_t)part_mb,
519 		partp->dp_flag,
520 		partp->dp_flag == ACTIVE ? " (active)" : "");
521 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
522 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
523 		,partp->dp_shd
524 		,DPSECT(partp->dp_ssect)
525 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
526 		,partp->dp_ehd
527 		,DPSECT(partp->dp_esect));
528 }
529 
530 
531 static void
532 init_boot(void)
533 {
534 	const char *fname;
535 	int boot_fd, n;
536 	struct stat sb;
537 
538 	fname = b_flag ? b_flag : "/boot/mbr";
539 	if ((boot_fd = open(fname, O_RDONLY)) == -1 ||
540 	    fstat(boot_fd, &sb) == -1)
541 		err(1, "%s", fname);
542 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
543 		errx(1, "%s: length must be a multiple of sector size", fname);
544 	if (mboot.bootinst != NULL)
545 		free(mboot.bootinst);
546 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
547 		errx(1, "%s: unable to allocate read buffer", fname);
548 	if ((n = read(boot_fd, mboot.bootinst, mboot.bootinst_size)) == -1 ||
549 	    close(boot_fd))
550 		err(1, "%s", fname);
551 	if (n != mboot.bootinst_size)
552 		errx(1, "%s: short read", fname);
553 }
554 
555 
556 static void
557 init_sector0(unsigned long start)
558 {
559 struct dos_partition *partp = (struct dos_partition *) (&mboot.parts[3]);
560 
561 	init_boot();
562 
563 	partp->dp_typ = DOSPTYP_DFLYBSD;
564 	partp->dp_flag = ACTIVE;
565 	start = roundup(start, dos_sectors);
566 	if (start == 0)
567 		start = dos_sectors;
568 	partp->dp_start = start;
569 	if (disksecs - start > 0xFFFFFFFFU) {
570 		printf("Warning: Ending logical block > 2TB, using max value\n");
571 		partp->dp_size = 0xFFFFFFFFU;
572 	} else {
573 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
574 	}
575 
576 	dos(partp);
577 }
578 
579 static void
580 change_part(int i)
581 {
582 struct dos_partition *partp = ((struct dos_partition *) &mboot.parts) + i - 1;
583 
584     printf("The data for partition %d is:\n", i);
585     print_part(i);
586 
587     if (u_flag && ok("Do you want to change it?")) {
588 	int tmp;
589 
590 	if (i_flag) {
591 		bzero((char *)partp, sizeof (struct dos_partition));
592 		if (i == 4) {
593 			init_sector0(1);
594 			printf("\nThe static data for the DOS partition 4 has been reinitialized to:\n");
595 			print_part(i);
596 		}
597 	}
598 
599 	do {
600 		Decimal("sysid (165=DragonFly)", partp->dp_typ, tmp);
601 		Decimal("start", partp->dp_start, tmp);
602 		Decimal("size", partp->dp_size, tmp);
603 		if (!sanitize_partition(partp)) {
604 			warnx("ERROR: failed to adjust; setting sysid to 0");
605 			partp->dp_typ = 0;
606 		}
607 
608 		if (ok("Explicitly specify beg/end address ?"))
609 		{
610 			int	tsec,tcyl,thd;
611 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
612 			thd = partp->dp_shd;
613 			tsec = DPSECT(partp->dp_ssect);
614 			Decimal("beginning cylinder", tcyl, tmp);
615 			Decimal("beginning head", thd, tmp);
616 			Decimal("beginning sector", tsec, tmp);
617 			if (tcyl > MAXCYL && C_flag == 0) {
618 				printf("Warning: starting cylinder wraps, using all 1's\n");
619 				partp->dp_scyl = -1;
620 				partp->dp_ssect = -1;
621 				partp->dp_shd = -1;
622 			} else {
623 				partp->dp_scyl = DOSCYL(tcyl);
624 				partp->dp_ssect = DOSSECT(tsec,tcyl);
625 				partp->dp_shd = thd;
626 			}
627 
628 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
629 			thd = partp->dp_ehd;
630 			tsec = DPSECT(partp->dp_esect);
631 			Decimal("ending cylinder", tcyl, tmp);
632 			Decimal("ending head", thd, tmp);
633 			Decimal("ending sector", tsec, tmp);
634 			if (tcyl > MAXCYL && C_flag == 0) {
635 				printf("Warning: ending cylinder wraps, using all 1's\n");
636 				partp->dp_ecyl = -1;
637 				partp->dp_esect = -1;
638 				partp->dp_ehd = -1;
639 			} else {
640 				partp->dp_ecyl = DOSCYL(tcyl);
641 				partp->dp_esect = DOSSECT(tsec,tcyl);
642 				partp->dp_ehd = thd;
643 			}
644 		} else
645 			dos(partp);
646 
647 		print_part(i);
648 	} while (!ok("Are we happy with this entry?"));
649     }
650 }
651 
652 static void
653 print_params(void)
654 {
655 	printf("parameters extracted from device are:\n");
656 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
657 			,cyls,heads,sectors,cylsecs);
658 	if ((dos_sectors > MAX_SECTORS_PER_TRACK) || (dos_cyls > MAXCYL) || (dos_heads > MAX_HEADS))
659 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
660 	printf("parameters to be used for BIOS calculations are:\n");
661 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
662 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
663 }
664 
665 static void
666 change_active(int which)
667 {
668 	struct dos_partition *partp = &mboot.parts[0];
669 	int active, i, new, tmp;
670 
671 	active = -1;
672 	for (i = 0; i < NDOSPART; i++) {
673 		if ((partp[i].dp_flag & ACTIVE) == 0)
674 			continue;
675 		printf("Partition %d is marked active\n", i + 1);
676 		if (active == -1)
677 			active = i + 1;
678 	}
679 	if (a_flag && which != -1)
680 		active = which;
681 	else if (active == -1)
682 		active = 1;
683 
684 	if (!ok("Do you want to change the active partition?"))
685 		return;
686 setactive:
687 	do {
688 		new = active;
689 		Decimal("active partition", new, tmp);
690 		if (new < 1 || new > 4) {
691 			printf("Active partition number must be in range 1-4."
692 					"  Try again.\n");
693 			goto setactive;
694 		}
695 		active = new;
696 	} while (!ok("Are you happy with this choice"));
697 	for (i = 0; i < NDOSPART; i++)
698 		partp[i].dp_flag = 0;
699 	if (active > 0 && active <= NDOSPART)
700 		partp[active-1].dp_flag = ACTIVE;
701 }
702 
703 static void
704 change_code(void)
705 {
706 	if (ok("Do you want to change the boot code?"))
707 		init_boot();
708 }
709 
710 void
711 get_params_to_use(void)
712 {
713 	int	tmp;
714 	print_params();
715 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
716 	{
717 		do
718 		{
719 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp);
720 			Decimal("BIOS's idea of #heads", dos_heads, tmp);
721 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp);
722 			dos_cylsecs = dos_heads * dos_sectors;
723 			print_params();
724 		}
725 		while(!ok("Are you happy with this choice"));
726 	}
727 }
728 
729 
730 /***********************************************\
731 * Change real numbers into strange dos numbers	*
732 \***********************************************/
733 static void
734 dos(struct dos_partition *partp)
735 {
736 	int cy, sec;
737 	uint32_t end;
738 
739 	if (partp->dp_typ == 0 && partp->dp_start == 0 && partp->dp_size == 0) {
740 		memcpy(partp, &mtpart, sizeof(*partp));
741 		return;
742 	}
743 
744 	/* Start c/h/s. */
745 	cy = partp->dp_start / dos_cylsecs;
746 	sec = partp->dp_start % dos_sectors + 1;
747 	if (cy > MAXCYL && C_flag == 0) {
748 	    printf("Warning: starting cylinder wraps, using all 1's\n");
749 	    partp->dp_shd = -1;
750 	    partp->dp_scyl = -1;
751 	    partp->dp_ssect = -1;
752 	} else {
753 	    partp->dp_shd = partp->dp_start % dos_cylsecs / dos_sectors;
754 	    partp->dp_scyl = DOSCYL(cy);
755 	    partp->dp_ssect = DOSSECT(sec, cy);
756 	}
757 
758 	/* End c/h/s. */
759 	end = partp->dp_start + partp->dp_size - 1;
760 	cy = end / dos_cylsecs;
761 	sec = end % dos_sectors + 1;
762 	if (cy > MAXCYL && C_flag == 0) {
763 	    printf("Warning: ending cylinder wraps, using all 1's\n");
764 	    partp->dp_ehd = -1;
765 	    partp->dp_ecyl = -1;
766 	    partp->dp_esect = -1;
767 	} else {
768 	    partp->dp_ehd = end % dos_cylsecs / dos_sectors;
769 	    partp->dp_ecyl = DOSCYL(cy);
770 	    partp->dp_esect = DOSSECT(sec, cy);
771 	}
772 }
773 
774 static void
775 erase_partition(int i)
776 {
777 	struct	  dos_partition *partp;
778 	off_t ioarg[2];
779 
780 	char sysctl_name[64];
781 	int trim_enabled = 0;
782 	size_t olen = sizeof(trim_enabled);
783 	char *dev_name = strdup(disk);
784 
785 	dev_name = strtok(dev_name + strlen("/dev/da"),"s");
786 	sprintf(sysctl_name, "kern.cam.da.%s.trim_enabled", dev_name);
787 	if (sysctlbyname(sysctl_name, &trim_enabled, &olen, NULL, 0) < 0) {
788 		printf("Device:%s does not support the TRIM command\n", disk);
789 		usage();
790 	}
791 	if (!trim_enabled) {
792 		printf("Erase device option selected, but sysctl (%s) "
793 		    "is not enabled\n",sysctl_name);
794 		usage();
795 	}
796 	partp = ((struct dos_partition *) &mboot.parts) + i;
797 	printf("erase sectors:%u %u\n",
798 	    partp->dp_start,
799 	    partp->dp_size);
800 
801 	/* Trim the Device */
802 	ioarg[0] = partp->dp_start;
803 	ioarg[0] *=secsize;
804 	ioarg[1] = partp->dp_size;
805 	ioarg[1] *=secsize;
806 
807 	if (ioctl(fd, IOCTLTRIM, ioarg) < 0) {
808 		printf("Device trim failed\n");
809 		usage ();
810 	}
811 }
812 
813 	/* Getting device status */
814 
815 static int
816 open_disk(void)
817 {
818 	struct stat 	st;
819 
820 	if (stat(disk, &st) == -1) {
821 		if (errno == ENOENT)
822 			return -2;
823 		warnx("can't get file status of %s", disk);
824 		return -1;
825 	}
826 	if (!(st.st_mode & S_IFCHR) && p_flag == 0)
827 		warnx("device %s is not character special", disk);
828 	if ((fd = open(disk,
829 	    a_flag || I_flag || B_flag || u_flag ? O_RDWR : O_RDONLY)) == -1) {
830 		if (errno == ENXIO)
831 			return -2;
832 		warnx("can't open device %s", disk);
833 		return -1;
834 	}
835 	if (get_params() == -1) {
836 		warnx("can't get disk parameters on %s", disk);
837 		return -1;
838 	}
839 	return fd;
840 }
841 
842 static ssize_t
843 read_disk(off_t sector, void *buf)
844 {
845 	lseek(fd,(sector * 512), 0);
846 	if (secsize == 0)
847 		for(secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE; secsize *= 2)
848 			{
849 			/* try the read */
850 			int size = read(fd, buf, secsize);
851 			if (size == secsize)
852 				/* it worked so return */
853 				return secsize;
854 			}
855 	else
856 		return read(fd, buf, secsize);
857 
858 	/* we failed to read at any of the sizes */
859 	return -1;
860 }
861 
862 static ssize_t
863 write_disk(off_t sector, void *buf)
864 {
865 	lseek(fd,(sector * 512), 0);
866 	/* write out in the size that the read_disk found worked */
867 	return write(fd, buf, secsize);
868 }
869 
870 static int
871 get_params(void)
872 {
873     struct partinfo partinfo;	/* disk parameters */
874     struct stat st;
875 
876     /*
877      * NOTE: When faking up the CHS for a file image (e.g. for USB),
878      *	     we must use max values.  If we do not then an overflowed
879      *       cylinder count will, by convention, set the CHS fields to
880      *       all 1's.  The heads and sectors in the CHS fields will then
881      *       exceed the basic geometry which can cause BIOSes to brick.
882      */
883     if (ioctl(fd, DIOCGPART, &partinfo) == -1) {
884 	if (p_flag && fstat(fd, &st) == 0 && st.st_size) {
885 	    sectors = MAX_SECTORS_PER_TRACK;
886 	    heads = MAX_HEADS;
887 	    cylsecs = heads * sectors;
888 	    cyls = st.st_size / 512 / cylsecs;
889 	} else {
890 	    warnx("can't get disk parameters on %s; supplying dummy ones",
891 		  disk);
892 	    heads = 1;
893 	    cylsecs = heads * sectors;
894 	}
895     } else {
896 	cyls = partinfo.d_ncylinders;
897 	heads = partinfo.d_nheads;
898 	sectors = partinfo.d_secpertrack;
899 	cylsecs = heads * sectors;
900 	secsize = partinfo.media_blksize;
901     }
902     dos_cyls = cyls;
903     dos_heads = heads;
904     dos_sectors = sectors;
905     dos_cylsecs = cylsecs;
906     disksecs = (int64_t)cyls * heads * sectors;
907     return (disksecs);
908 }
909 
910 
911 static int
912 read_s0(void)
913 {
914 	mboot.bootinst_size = secsize;
915 	if (mboot.bootinst != NULL)
916 		free(mboot.bootinst);
917 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
918 		warnx("unable to allocate buffer to read fdisk "
919 		      "partition table");
920 		return -1;
921 	}
922 	if (read_disk(0, mboot.bootinst) == -1) {
923 		warnx("can't read fdisk partition table");
924 		return -1;
925 	}
926 	if (*(uint16_t *)&mboot.bootinst[DOSMAGICOFFSET] != BOOT_MAGIC) {
927 		warnx("invalid fdisk partition table found");
928 		/* So should we initialize things */
929 		return -1;
930 	}
931 	memcpy(mboot.parts, &mboot.bootinst[DOSPARTOFF], sizeof(mboot.parts));
932 	return 0;
933 }
934 
935 static int
936 write_s0(void)
937 {
938 #ifdef NOT_NOW
939 	int	flag = 1;
940 #endif
941 	int	sector;
942 
943 	memcpy(&mboot.bootinst[DOSPARTOFF], mboot.parts, sizeof(mboot.parts));
944 	/*
945 	 * write enable label sector before write (if necessary),
946 	 * disable after writing.
947 	 * needed if the disklabel protected area also protects
948 	 * sector 0. (e.g. empty disk)
949 	 */
950 #ifdef NOT_NOW
951 	if (ioctl(fd, DIOCWLABEL, &flag) < 0)
952 		warn("ioctl DIOCWLABEL");
953 #endif
954 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
955 		if (write_disk(sector,
956 			       &mboot.bootinst[sector * secsize]) == -1) {
957 			warn("can't write fdisk partition table");
958 #ifdef NOT_NOW
959 			flag = 0;
960 			ioctl(fd, DIOCWLABEL, &flag);
961 #endif
962 			return -1;
963 		}
964 #ifdef NOT_NOW
965 	flag = 0;
966 	ioctl(fd, DIOCWLABEL, &flag);
967 #endif
968 	return(0);
969 }
970 
971 
972 static int
973 ok(const char *str)
974 {
975 	printf("%s [n] ", str);
976 	fflush(stdout);
977 	if (fgets(lbuf, LBUF, stdin) == NULL)
978 		exit(1);
979 	lbuf[strlen(lbuf)-1] = 0;
980 
981 	if (*lbuf &&
982 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
983 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
984 		return 1;
985 	else
986 		return 0;
987 }
988 
989 static int
990 decimal(const char *str, int *num, int deflt)
991 {
992 	int acc = 0, c;
993 	char *cp;
994 
995 	while (1) {
996 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
997 		fflush(stdout);
998 		if (fgets(lbuf, LBUF, stdin) == NULL)
999 			exit(1);
1000 		lbuf[strlen(lbuf)-1] = 0;
1001 
1002 		if (!*lbuf)
1003 			return 0;
1004 
1005 		cp = lbuf;
1006 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
1007 		if (!c)
1008 			return 0;
1009 		while ((c = *cp++)) {
1010 			if (c <= '9' && c >= '0')
1011 				acc = acc * 10 + c - '0';
1012 			else
1013 				break;
1014 		}
1015 		if (c == ' ' || c == '\t')
1016 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
1017 		if (!c) {
1018 			*num = acc;
1019 			return 1;
1020 		} else
1021 			printf("%s is an invalid decimal number.  Try again.\n",
1022 				lbuf);
1023 	}
1024 
1025 }
1026 
1027 static const char *
1028 get_type(int type)
1029 {
1030 	int	numentries = NELEM(part_types);
1031 	int	counter = 0;
1032 	struct	part_type *ptr = part_types;
1033 
1034 
1035 	while(counter < numentries)
1036 	{
1037 		if (ptr->type == type)
1038 		{
1039 			return(ptr->name);
1040 		}
1041 		ptr++;
1042 		counter++;
1043 	}
1044 	return("unknown");
1045 }
1046 
1047 
1048 static void
1049 parse_config_line(char *line, CMD *command)
1050 {
1051     char	*cp, *end;
1052 
1053     cp = line;
1054     while (1)	/* dirty trick used to insure one exit point for this
1055 		   function */
1056     {
1057 	memset(command, 0, sizeof(*command));
1058 
1059 	while (isspace(*cp)) ++cp;
1060 	if (*cp == '\0' || *cp == '#')
1061 	{
1062 	    break;
1063 	}
1064 	command->cmd = *cp++;
1065 
1066 	/*
1067 	 * Parse args
1068 	 */
1069 	while (1)
1070 	{
1071 	    while (isspace(*cp)) ++cp;
1072 	    if (*cp == '#')
1073 	    {
1074 		break;		/* found comment */
1075 	    }
1076 	    if (isalpha(*cp))
1077 	    {
1078 		command->args[command->n_args].argtype = *cp++;
1079 	    }
1080 	    if (!isdigit(*cp))
1081 	    {
1082 		break;		/* assume end of line */
1083 	    }
1084 	    end = NULL;
1085 	    command->args[command->n_args].arg_val = strtoll(cp, &end, 0);
1086 	    if (cp == end)
1087 	    {
1088 		break;		/* couldn't parse number */
1089 	    }
1090 	    cp = end;
1091 	    command->n_args++;
1092 	}
1093 	break;
1094     }
1095 }
1096 
1097 
1098 static int
1099 process_geometry(CMD *command)
1100 {
1101     int		status = 1, i;
1102 
1103     while (1)
1104     {
1105 	geom_processed = 1;
1106 	if (part_processed)
1107 	{
1108 	    warnx(
1109 	"ERROR line %d: the geometry specification line must occur before\n\
1110     all partition specifications",
1111 		    current_line_number);
1112 	    status = 0;
1113 	    break;
1114 	}
1115 	if (command->n_args != 3)
1116 	{
1117 	    warnx("ERROR line %d: incorrect number of geometry args",
1118 		    current_line_number);
1119 	    status = 0;
1120 	    break;
1121 	}
1122 	dos_cyls = -1;
1123 	dos_heads = -1;
1124 	dos_sectors = -1;
1125 	for (i = 0; i < 3; ++i)
1126 	{
1127 	    switch (command->args[i].argtype)
1128 	    {
1129 	    case 'c':
1130 		dos_cyls = command->args[i].arg_val;
1131 		break;
1132 	    case 'h':
1133 		dos_heads = command->args[i].arg_val;
1134 		break;
1135 	    case 's':
1136 		dos_sectors = command->args[i].arg_val;
1137 		break;
1138 	    default:
1139 		warnx(
1140 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1141 			current_line_number, command->args[i].argtype,
1142 			command->args[i].argtype);
1143 		status = 0;
1144 		break;
1145 	    }
1146 	}
1147 	if (status == 0)
1148 	{
1149 	    break;
1150 	}
1151 
1152 	dos_cylsecs = dos_heads * dos_sectors;
1153 
1154 	/*
1155 	 * Do sanity checks on parameter values
1156 	 */
1157 	if (dos_cyls < 0)
1158 	{
1159 	    warnx("ERROR line %d: number of cylinders not specified",
1160 		    current_line_number);
1161 	    status = 0;
1162 	}
1163 	if (dos_cyls == 0 || dos_cyls > 1024)
1164 	{
1165 	    warnx(
1166 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1167     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1168     is dedicated to DragonFly)",
1169 		    current_line_number, dos_cyls);
1170 	}
1171 
1172 	if (dos_heads < 0)
1173 	{
1174 	    warnx("ERROR line %d: number of heads not specified",
1175 		    current_line_number);
1176 	    status = 0;
1177 	}
1178 	else if (dos_heads < 1 || dos_heads > 256)
1179 	{
1180 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1181 		    current_line_number);
1182 	    status = 0;
1183 	}
1184 
1185 	if (dos_sectors < 0)
1186 	{
1187 	    warnx("ERROR line %d: number of sectors not specified",
1188 		    current_line_number);
1189 	    status = 0;
1190 	}
1191 	else if (dos_sectors < MIN_SECTORS_PER_TRACK || dos_sectors > MAX_SECTORS_PER_TRACK)
1192 	{
1193 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1194 		    current_line_number);
1195 	    status = 0;
1196 	}
1197 
1198 	break;
1199     }
1200     return (status);
1201 }
1202 
1203 
1204 static int
1205 process_partition(CMD *command)
1206 {
1207     int				status = 0, part;
1208     uint32_t			prev_head_boundary, prev_cyl_boundary;
1209     uint32_t			adj_size, max_end;
1210     struct dos_partition	*partp;
1211 
1212     while (1)
1213     {
1214 	part_processed = 1;
1215 	if (command->n_args != 4)
1216 	{
1217 	    warnx("ERROR line %d: incorrect number of partition args",
1218 		    current_line_number);
1219 	    break;
1220 	}
1221 	part = command->args[0].arg_val;
1222 	if (part < 1 || part > 4)
1223 	{
1224 	    warnx("ERROR line %d: invalid partition number %d",
1225 		    current_line_number, part);
1226 	    break;
1227 	}
1228 	partp = ((struct dos_partition *) &mboot.parts) + part - 1;
1229 	bzero((char *)partp, sizeof (struct dos_partition));
1230 	partp->dp_typ = command->args[1].arg_val;
1231 	partp->dp_start = command->args[2].arg_val;
1232 	partp->dp_size = command->args[3].arg_val;
1233 	max_end = partp->dp_start + partp->dp_size;
1234 
1235 	if (partp->dp_typ == 0)
1236 	{
1237 	    /*
1238 	     * Get out, the partition is marked as unused.
1239 	     */
1240 	    /*
1241 	     * Insure that it's unused.
1242 	     */
1243 	    bzero((char *)partp, sizeof (struct dos_partition));
1244 	    status = 1;
1245 	    break;
1246 	}
1247 
1248 	/*
1249 	 * Adjust start upwards, if necessary, to fall on an head boundary.
1250 	 */
1251 	if (partp->dp_start % dos_sectors != 0)
1252 	{
1253 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1254 	    if (max_end < (uint32_t)dos_sectors ||
1255 		prev_head_boundary > max_end - dos_sectors)
1256 	    {
1257 		/*
1258 		 * Can't go past end of partition
1259 		 */
1260 		warnx(
1261 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1262     a head boundary",
1263 			current_line_number, part);
1264 		break;
1265 	    }
1266 	    warnx(
1267 	"WARNING: adjusting start offset of partition %d\n\
1268     from %u to %u, to fall on a head boundary",
1269 		    part, (u_int)partp->dp_start,
1270 		    (u_int)(prev_head_boundary + dos_sectors));
1271 	    partp->dp_start = prev_head_boundary + dos_sectors;
1272 	}
1273 
1274 	/*
1275 	 * Adjust size downwards, if necessary, to fall on a cylinder
1276 	 * boundary.
1277 	 */
1278 	prev_cyl_boundary =
1279 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1280 	if (prev_cyl_boundary > partp->dp_start)
1281 	    adj_size = prev_cyl_boundary - partp->dp_start;
1282 	else
1283 	{
1284 	    warnx(
1285 	"ERROR: could not adjust partition to start on a head boundary\n\
1286     and end on a cylinder boundary.");
1287 	    return (0);
1288 	}
1289 	if (adj_size != partp->dp_size)
1290 	{
1291 	    warnx(
1292 	"WARNING: adjusting size of partition %d from %u to %u\n\
1293     to end on a cylinder boundary",
1294 		    part, (u_int)partp->dp_size, (u_int)adj_size);
1295 	    partp->dp_size = adj_size;
1296 	}
1297 	if (partp->dp_size == 0)
1298 	{
1299 	    warnx("ERROR line %d: size of partition %d is zero",
1300 		    current_line_number, part);
1301 	    break;
1302 	}
1303 
1304 	dos(partp);
1305 	status = 1;
1306 	break;
1307     }
1308     return (status);
1309 }
1310 
1311 
1312 static int
1313 process_active(CMD *command)
1314 {
1315     int				status = 0, part, i;
1316     struct dos_partition	*partp;
1317 
1318     while (1)
1319     {
1320 	active_processed = 1;
1321 	if (command->n_args != 1)
1322 	{
1323 	    warnx("ERROR line %d: incorrect number of active args",
1324 		    current_line_number);
1325 	    status = 0;
1326 	    break;
1327 	}
1328 	part = command->args[0].arg_val;
1329 	if (part < 1 || part > 4)
1330 	{
1331 	    warnx("ERROR line %d: invalid partition number %d",
1332 		    current_line_number, part);
1333 	    break;
1334 	}
1335 	/*
1336 	 * Reset active partition
1337 	 */
1338 	partp = ((struct dos_partition *) &mboot.parts);
1339 	for (i = 0; i < NDOSPART; i++)
1340 	    partp[i].dp_flag = 0;
1341 	partp[part-1].dp_flag = ACTIVE;
1342 
1343 	status = 1;
1344 	break;
1345     }
1346     return (status);
1347 }
1348 
1349 
1350 static int
1351 process_line(char *line)
1352 {
1353     CMD		command;
1354     int		status = 1;
1355 
1356     while (1)
1357     {
1358 	parse_config_line(line, &command);
1359 	switch (command.cmd)
1360 	{
1361 	case 0:
1362 	    /*
1363 	     * Comment or blank line
1364 	     */
1365 	    break;
1366 	case 'g':
1367 	    /*
1368 	     * Set geometry
1369 	     */
1370 	    status = process_geometry(&command);
1371 	    break;
1372 	case 'p':
1373 	    status = process_partition(&command);
1374 	    break;
1375 	case 'a':
1376 	    status = process_active(&command);
1377 	    break;
1378 	default:
1379 	    status = 0;
1380 	    break;
1381 	}
1382 	break;
1383     }
1384     return (status);
1385 }
1386 
1387 
1388 static int
1389 read_config(char *config_file)
1390 {
1391     FILE	*fp = NULL;
1392     int		status = 1;
1393     char	buf[1010];
1394 
1395     while (1)	/* dirty trick used to insure one exit point for this
1396 		   function */
1397     {
1398 	if (strcmp(config_file, "-") != 0)
1399 	{
1400 	    /*
1401 	     * We're not reading from stdin
1402 	     */
1403 	    if ((fp = fopen(config_file, "r")) == NULL)
1404 	    {
1405 		status = 0;
1406 		break;
1407 	    }
1408 	}
1409 	else
1410 	{
1411 	    fp = stdin;
1412 	}
1413 	current_line_number = 0;
1414 	while (!feof(fp))
1415 	{
1416 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1417 	    {
1418 		break;
1419 	    }
1420 	    ++current_line_number;
1421 	    status = process_line(buf);
1422 	    if (status == 0)
1423 	    {
1424 		break;
1425 	    }
1426 	}
1427 	break;
1428     }
1429     if (fp)
1430     {
1431 	/*
1432 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1433 	 */
1434 	fclose(fp);
1435     }
1436     return (status);
1437 }
1438 
1439 
1440 static void
1441 reset_boot(void)
1442 {
1443     int				i;
1444     struct dos_partition	*partp;
1445 
1446     init_boot();
1447     for (i = 0; i < 4; ++i)
1448     {
1449 	partp = ((struct dos_partition *) &mboot.parts) + i;
1450 	bzero((char *)partp, sizeof (struct dos_partition));
1451     }
1452 }
1453 
1454 static int
1455 sanitize_partition(struct dos_partition *partp)
1456 {
1457     uint32_t			prev_head_boundary, prev_cyl_boundary;
1458     uint32_t			max_end, size, start;
1459 
1460     start = partp->dp_start;
1461     size = partp->dp_size;
1462     max_end = start + size;
1463     /* Only allow a zero size if the partition is being marked unused. */
1464     if (size == 0) {
1465 	if (start == 0 && partp->dp_typ == 0)
1466 	    return (1);
1467 	warnx("ERROR: size of partition is zero");
1468 	return (0);
1469     }
1470     /* Return if no adjustment is necessary. */
1471     if (start % dos_sectors == 0 && (start + size) % dos_sectors == 0)
1472 	return (1);
1473 
1474     if (start == 0) {
1475 	    warnx("WARNING: partition overlaps with partition table");
1476 	    if (ok("Correct this automatically?"))
1477 		    start = dos_sectors;
1478     }
1479     if (start % dos_sectors != 0)
1480 	warnx("WARNING: partition does not start on a head boundary");
1481     if ((start  +size) % dos_sectors != 0)
1482 	warnx("WARNING: partition does not end on a cylinder boundary");
1483     warnx("WARNING: this may confuse the BIOS or some operating systems");
1484     if (!ok("Correct this automatically?"))
1485 	return (1);
1486 
1487     /*
1488      * Adjust start upwards, if necessary, to fall on an head boundary.
1489      */
1490     if (start % dos_sectors != 0) {
1491 	prev_head_boundary = start / dos_sectors * dos_sectors;
1492 	if (max_end < (uint32_t)dos_sectors ||
1493 	    prev_head_boundary >= max_end - dos_sectors) {
1494 	    /*
1495 	     * Can't go past end of partition
1496 	     */
1497 	    warnx(
1498     "ERROR: unable to adjust start of partition to fall on a head boundary");
1499 	    return (0);
1500         }
1501 	start = prev_head_boundary + dos_sectors;
1502     }
1503 
1504     /*
1505      * Adjust size downwards, if necessary, to fall on a cylinder
1506      * boundary.
1507      */
1508     prev_cyl_boundary = ((start + size) / dos_cylsecs) * dos_cylsecs;
1509     if (prev_cyl_boundary > start)
1510 	size = prev_cyl_boundary - start;
1511     else {
1512 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1513     and end on a cylinder boundary.");
1514 	return (0);
1515     }
1516 
1517     /* Finally, commit any changes to partp and return. */
1518     if (start != partp->dp_start) {
1519 	warnx("WARNING: adjusting start offset of partition to %u",
1520 	    (u_int)start);
1521 	partp->dp_start = start;
1522     }
1523     if (size != partp->dp_size) {
1524 	warnx("WARNING: adjusting size of partition to %u", (u_int)size);
1525 	partp->dp_size = size;
1526     }
1527 
1528     return (1);
1529 }
1530