xref: /dragonfly/sbin/fdisk/fdisk.c (revision cae2835b)
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 	,{0x70, "DiskSecure Multi-Boot"}
178 	,{0x75, "PCIX"}
179 	,{0x77, "QNX4.x"}
180 	,{0x78, "QNX4.x 2nd part"}
181 	,{0x79, "QNX4.x 3rd part"}
182 	,{0x80, "Minix 1.1 ... 1.4a"}
183 	,{0x81, "Minix 1.4b ... 1.5.10"}
184 	,{0x82, "Linux swap or Solaris x86"}
185 	,{0x83, "Linux filesystem"}
186 	,{0x84, "OS/2 hidden C: drive"}
187 	,{0x85, "Linux extended"}
188 	,{0x86, "NTFS volume set??"}
189 	,{0x87, "NTFS volume set??"}
190 	,{0x93, "Amoeba filesystem"}
191 	,{0x94, "Amoeba bad block table"}
192 	,{0x9F, "BSD/OS"}
193 	,{0xA0, "Suspend to Disk"}
194 	,{0xA5, "DragonFly/FreeBSD/NetBSD/386BSD"}
195 	,{0xA6, "OpenBSD"}
196 	,{0xA7, "NEXTSTEP"}
197 	,{0xA9, "NetBSD"}
198 	,{0xAC, "IBM JFS"}
199 	,{0xB7, "BSDI BSD/386 filesystem"}
200 	,{0xB8, "BSDI BSD/386 swap"}
201 	,{0xBE, "Solaris x86 boot"}
202 	,{0xC1, "DRDOS/sec with 12-bit FAT"}
203 	,{0xC4, "DRDOS/sec with 16-bit FAT (< 32MB)"}
204 	,{0xC6, "DRDOS/sec with 16-bit FAT (>= 32MB)"}
205 	,{0xC7, "Syrinx"}
206 	,{0xDB, "Concurrent CPM or C.DOS or CTOS"}
207 	,{0xE1, "Speed"}
208 	,{0xE3, "Speed"}
209 	,{0xE4, "Speed"}
210 	,{0xEB, "BeOS file system"}
211 	,{0xEE, "EFI GPT"}
212 	,{0xEF, "EFI System Partition"}
213 	,{0xF1, "Speed"}
214 	,{0xF2, "DOS 3.3+ Secondary"}
215 	,{0xF4, "Speed"}
216 	,{0xFE, "SpeedStor >1024 cyl. or LANstep"}
217 	,{0xFF, "BBT (Bad Blocks Table)"}
218 };
219 
220 static void print_s0(int which);
221 static void print_part(int i);
222 static void init_sector0(unsigned long start);
223 static void init_boot(void);
224 static void change_part(int i);
225 static void print_params(void);
226 static void change_active(int which);
227 static void change_code(void);
228 static void get_params_to_use(void);
229 static void dos(struct dos_partition *partp);
230 static int open_disk(void);
231 static void erase_partition(int i);
232 static ssize_t read_disk(off_t sector, void *buf);
233 static ssize_t write_disk(off_t sector, void *buf);
234 static int get_params(void);
235 static int read_s0(void);
236 static int write_s0(void);
237 static int ok(const char *str);
238 static int decimal(const char *str, int *num, int deflt);
239 static const char *get_type(int type);
240 static int read_config(char *config_file);
241 static void reset_boot(void);
242 static int sanitize_partition(struct dos_partition *);
243 static void usage(void);
244 
245 int
246 main(int argc, char *argv[])
247 {
248 	int	c, i;
249 
250 	while ((c = getopt(argc, argv, "BCEIab:f:p:istuv1234")) != -1)
251 		switch (c) {
252 		case 'B':
253 			B_flag = 1;
254 			break;
255 		case 'C':
256 			C_flag = 1;
257 			break;
258 		case 'E':
259 			E_flag = 1;
260 			break;
261 		case 'I':
262 			I_flag = 1;
263 			break;
264 		case 'a':
265 			a_flag = 1;
266 			break;
267 		case 'b':
268 			b_flag = optarg;
269 			break;
270 		case 'f':
271 			f_flag = optarg;
272 			break;
273 		case 'p':
274 			disk = optarg;
275 			p_flag = 1;
276 			break;
277 		case 'i':
278 			i_flag = 1;
279 			break;
280 		case 's':
281 			s_flag = 1;
282 			break;
283 		case 't':
284 			t_flag = 1;
285 			break;
286 		case 'u':
287 			u_flag = 1;
288 			break;
289 		case 'v':
290 			v_flag = 1;
291 			break;
292 		case '1':
293 		case '2':
294 		case '3':
295 		case '4':
296 			partition = c - '0';
297 			break;
298 		default:
299 			usage();
300 		}
301 	if (f_flag || i_flag)
302 		u_flag = 1;
303 	if (t_flag)
304 		v_flag = 1;
305 	argc -= optind;
306 	argv += optind;
307 
308 	if (argc > 0) {
309 		disk = getdevpath(argv[0], 0);
310 		if (open_disk() < 0)
311 			err(1, "cannot open disk %s", disk);
312 	} else if (disk == NULL) {
313 		int rv = 0;
314 
315 		for(i = 0; disks[i]; i++)
316 		{
317 			disk = disks[i];
318 			rv = open_disk();
319 			if (rv != -2) break;
320 		}
321 		if (rv < 0)
322 			err(1, "cannot open any disk");
323 	} else {
324 		if (open_disk() < 0)
325 			err(1, "cannot open disk %s", disk);
326 	}
327 
328 	/* (abu)use mboot.bootinst to probe for the sector size */
329 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
330 		err(1, "cannot allocate buffer to determine disk sector size");
331 	read_disk(0, mboot.bootinst);
332 	free(mboot.bootinst);
333 	mboot.bootinst = NULL;
334 
335 	if (s_flag)
336 	{
337 		int j;
338 		struct dos_partition *partp;
339 
340 		if (read_s0())
341 			err(1, "read_s0");
342 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
343 		    dos_sectors);
344 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
345 		for (j = 0; j < NDOSPART; j++) {
346 			partp = ((struct dos_partition *) &mboot.parts) + j;
347 			if (partp->dp_start == 0 && partp->dp_size == 0)
348 				continue;
349 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", j + 1,
350 			    (u_long) partp->dp_start,
351 			    (u_long) partp->dp_size, partp->dp_typ,
352 			    partp->dp_flag);
353 		}
354 		exit(0);
355 	}
356 
357 	printf("******* Working on device %s *******\n",disk);
358 
359 	if (I_flag)
360 	{
361 		struct dos_partition *partp;
362 
363 		read_s0();
364 		reset_boot();
365 		partp = (struct dos_partition *) (&mboot.parts[0]);
366 		partp->dp_typ = DOSPTYP_386BSD;
367 		partp->dp_flag = ACTIVE;
368 		partp->dp_start = dos_sectors;
369 		if (disksecs - dos_sectors > 0xFFFFFFFFU) {
370 			printf("Warning: Ending logical block > 2TB, using max value\n");
371 			partp->dp_size = 0xFFFFFFFFU;
372 		} else {
373 			partp->dp_size = (disksecs / dos_cylsecs) *
374 					dos_cylsecs - dos_sectors;
375 		}
376 		dos(partp);
377 		if (v_flag)
378 			print_s0(-1);
379 
380 		if (E_flag) {
381 			/* Trim now if we're using the entire device */
382 			erase_partition(0);
383 		}
384 
385 		if (!t_flag)
386 			write_s0();
387 		exit(0);
388 	}
389 	if (f_flag)
390 	{
391 	    if (read_s0() || i_flag)
392 	    {
393 		reset_boot();
394 	    }
395 
396 	    if (!read_config(f_flag))
397 	    {
398 		exit(1);
399 	    }
400 	    if (v_flag)
401 	    {
402 		print_s0(-1);
403 	    }
404 	    if (!t_flag)
405 	    {
406 		write_s0();
407 	    }
408 	}
409 	else
410 	{
411 	    if (u_flag)
412 	    {
413 		get_params_to_use();
414 	    }
415 	    else
416 	    {
417 		print_params();
418 	    }
419 
420 	    if (read_s0())
421 		init_sector0(dos_sectors);
422 
423 	    printf("Media sector size is %d\n", secsize);
424 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
425 	    printf("Information from DOS bootblock is:\n");
426 	    if (partition == -1)
427 		for (i = 1; i <= NDOSPART; i++)
428 		    change_part(i);
429 	    else
430 		change_part(partition);
431 
432 	    if (u_flag || a_flag)
433 		change_active(partition);
434 
435 	    if (B_flag)
436 		change_code();
437 
438 	    if (u_flag || a_flag || B_flag) {
439 		if (!t_flag)	{
440 		    printf("\nWe haven't changed the partition table yet.  ");
441 		    printf("This is your last chance.\n");
442 		}
443 		print_s0(-1);
444 		if (!t_flag)	{
445 		    if (ok("Should we write new partition table?")) {
446 			if (E_flag && u_flag) {
447 			    /*
448 			     * Trim now because we've committed to
449 			     * updating the partition.
450 			     */
451 			    if (partition == -1)
452 			        for (i = 0; i < NDOSPART; i++)
453 			            erase_partition(i);
454 				else
455 			            erase_partition(partition);
456 			}
457 			write_s0();
458 		    }
459 		}
460 		else
461 		{
462 		    printf("\n-t flag specified -- partition table not written.\n");
463 		}
464 	    }
465 	}
466 
467 	exit(0);
468 }
469 
470 static void
471 usage(void)
472 {
473 	fprintf(stderr, "%s%s",
474 		"usage: fdisk [-BCEIaistu] [-b bootcode] [-p diskimage] [-1234] [disk]\n",
475 		"       fdisk -f configfile [-itv] [disk]\n");
476         exit(1);
477 }
478 
479 static void
480 print_s0(int which)
481 {
482 	int	i;
483 
484 	print_params();
485 	printf("Information from DOS bootblock is:\n");
486 	if (which == -1)
487 		for (i = 1; i <= NDOSPART; i++)
488 			printf("%d: ", i), print_part(i);
489 	else
490 		print_part(which);
491 }
492 
493 static struct dos_partition mtpart = { 0 };
494 
495 static void
496 print_part(int i)
497 {
498 	struct	  dos_partition *partp;
499 	uint64_t part_mb;
500 
501 	partp = ((struct dos_partition *) &mboot.parts) + i - 1;
502 
503 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
504 		printf("<UNUSED>\n");
505 		return;
506 	}
507 	/*
508 	 * Be careful not to overflow.
509 	 */
510 	part_mb = partp->dp_size;
511 	part_mb *= secsize;
512 	part_mb /= (1024 * 1024);
513 	printf("sysid %d,(%s)\n", partp->dp_typ, get_type(partp->dp_typ));
514 	printf("    start %lu, size %lu (%jd Meg), flag %x%s\n",
515 		(u_long)partp->dp_start,
516 		(u_long)partp->dp_size,
517 		(intmax_t)part_mb,
518 		partp->dp_flag,
519 		partp->dp_flag == ACTIVE ? " (active)" : "");
520 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
521 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
522 		,partp->dp_shd
523 		,DPSECT(partp->dp_ssect)
524 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
525 		,partp->dp_ehd
526 		,DPSECT(partp->dp_esect));
527 }
528 
529 
530 static void
531 init_boot(void)
532 {
533 	const char *fname;
534 	int boot_fd, n;
535 	struct stat sb;
536 
537 	fname = b_flag ? b_flag : "/boot/mbr";
538 	if ((boot_fd = open(fname, O_RDONLY)) == -1 ||
539 	    fstat(boot_fd, &sb) == -1)
540 		err(1, "%s", fname);
541 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
542 		errx(1, "%s: length must be a multiple of sector size", fname);
543 	if (mboot.bootinst != NULL)
544 		free(mboot.bootinst);
545 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
546 		errx(1, "%s: unable to allocate read buffer", fname);
547 	if ((n = read(boot_fd, mboot.bootinst, mboot.bootinst_size)) == -1 ||
548 	    close(boot_fd))
549 		err(1, "%s", fname);
550 	if (n != mboot.bootinst_size)
551 		errx(1, "%s: short read", fname);
552 }
553 
554 
555 static void
556 init_sector0(unsigned long start)
557 {
558 struct dos_partition *partp = (struct dos_partition *) (&mboot.parts[3]);
559 
560 	init_boot();
561 
562 	partp->dp_typ = DOSPTYP_386BSD;
563 	partp->dp_flag = ACTIVE;
564 	start = roundup(start, dos_sectors);
565 	if (start == 0)
566 		start = dos_sectors;
567 	partp->dp_start = start;
568 	if (disksecs - start > 0xFFFFFFFFU) {
569 		printf("Warning: Ending logical block > 2TB, using max value\n");
570 		partp->dp_size = 0xFFFFFFFFU;
571 	} else {
572 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
573 	}
574 
575 	dos(partp);
576 }
577 
578 static void
579 change_part(int i)
580 {
581 struct dos_partition *partp = ((struct dos_partition *) &mboot.parts) + i - 1;
582 
583     printf("The data for partition %d is:\n", i);
584     print_part(i);
585 
586     if (u_flag && ok("Do you want to change it?")) {
587 	int tmp;
588 
589 	if (i_flag) {
590 		bzero((char *)partp, sizeof (struct dos_partition));
591 		if (i == 4) {
592 			init_sector0(1);
593 			printf("\nThe static data for the DOS partition 4 has been reinitialized to:\n");
594 			print_part(i);
595 		}
596 	}
597 
598 	do {
599 		Decimal("sysid (165=DragonFly)", partp->dp_typ, tmp);
600 		Decimal("start", partp->dp_start, tmp);
601 		Decimal("size", partp->dp_size, tmp);
602 		if (!sanitize_partition(partp)) {
603 			warnx("ERROR: failed to adjust; setting sysid to 0");
604 			partp->dp_typ = 0;
605 		}
606 
607 		if (ok("Explicitly specify beg/end address ?"))
608 		{
609 			int	tsec,tcyl,thd;
610 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
611 			thd = partp->dp_shd;
612 			tsec = DPSECT(partp->dp_ssect);
613 			Decimal("beginning cylinder", tcyl, tmp);
614 			Decimal("beginning head", thd, tmp);
615 			Decimal("beginning sector", tsec, tmp);
616 			if (tcyl > MAXCYL && C_flag == 0) {
617 				printf("Warning: starting cylinder wraps, using all 1's\n");
618 				partp->dp_scyl = -1;
619 				partp->dp_ssect = -1;
620 				partp->dp_shd = -1;
621 			} else {
622 				partp->dp_scyl = DOSCYL(tcyl);
623 				partp->dp_ssect = DOSSECT(tsec,tcyl);
624 				partp->dp_shd = thd;
625 			}
626 
627 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
628 			thd = partp->dp_ehd;
629 			tsec = DPSECT(partp->dp_esect);
630 			Decimal("ending cylinder", tcyl, tmp);
631 			Decimal("ending head", thd, tmp);
632 			Decimal("ending sector", tsec, tmp);
633 			if (tcyl > MAXCYL && C_flag == 0) {
634 				printf("Warning: ending cylinder wraps, using all 1's\n");
635 				partp->dp_ecyl = -1;
636 				partp->dp_esect = -1;
637 				partp->dp_ehd = -1;
638 			} else {
639 				partp->dp_ecyl = DOSCYL(tcyl);
640 				partp->dp_esect = DOSSECT(tsec,tcyl);
641 				partp->dp_ehd = thd;
642 			}
643 		} else
644 			dos(partp);
645 
646 		print_part(i);
647 	} while (!ok("Are we happy with this entry?"));
648     }
649 }
650 
651 static void
652 print_params(void)
653 {
654 	printf("parameters extracted from device are:\n");
655 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
656 			,cyls,heads,sectors,cylsecs);
657 	if ((dos_sectors > MAX_SECTORS_PER_TRACK) || (dos_cyls > MAXCYL) || (dos_heads > MAX_HEADS))
658 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
659 	printf("parameters to be used for BIOS calculations are:\n");
660 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
661 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
662 }
663 
664 static void
665 change_active(int which)
666 {
667 	struct dos_partition *partp = &mboot.parts[0];
668 	int active, i, new, tmp;
669 
670 	active = -1;
671 	for (i = 0; i < NDOSPART; i++) {
672 		if ((partp[i].dp_flag & ACTIVE) == 0)
673 			continue;
674 		printf("Partition %d is marked active\n", i + 1);
675 		if (active == -1)
676 			active = i + 1;
677 	}
678 	if (a_flag && which != -1)
679 		active = which;
680 	else if (active == -1)
681 		active = 1;
682 
683 	if (!ok("Do you want to change the active partition?"))
684 		return;
685 setactive:
686 	do {
687 		new = active;
688 		Decimal("active partition", new, tmp);
689 		if (new < 1 || new > 4) {
690 			printf("Active partition number must be in range 1-4."
691 					"  Try again.\n");
692 			goto setactive;
693 		}
694 		active = new;
695 	} while (!ok("Are you happy with this choice"));
696 	for (i = 0; i < NDOSPART; i++)
697 		partp[i].dp_flag = 0;
698 	if (active > 0 && active <= NDOSPART)
699 		partp[active-1].dp_flag = ACTIVE;
700 }
701 
702 static void
703 change_code(void)
704 {
705 	if (ok("Do you want to change the boot code?"))
706 		init_boot();
707 }
708 
709 void
710 get_params_to_use(void)
711 {
712 	int	tmp;
713 	print_params();
714 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
715 	{
716 		do
717 		{
718 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp);
719 			Decimal("BIOS's idea of #heads", dos_heads, tmp);
720 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp);
721 			dos_cylsecs = dos_heads * dos_sectors;
722 			print_params();
723 		}
724 		while(!ok("Are you happy with this choice"));
725 	}
726 }
727 
728 
729 /***********************************************\
730 * Change real numbers into strange dos numbers	*
731 \***********************************************/
732 static void
733 dos(struct dos_partition *partp)
734 {
735 	int cy, sec;
736 	uint32_t end;
737 
738 	if (partp->dp_typ == 0 && partp->dp_start == 0 && partp->dp_size == 0) {
739 		memcpy(partp, &mtpart, sizeof(*partp));
740 		return;
741 	}
742 
743 	/* Start c/h/s. */
744 	cy = partp->dp_start / dos_cylsecs;
745 	sec = partp->dp_start % dos_sectors + 1;
746 	if (cy > MAXCYL && C_flag == 0) {
747 	    printf("Warning: starting cylinder wraps, using all 1's\n");
748 	    partp->dp_shd = -1;
749 	    partp->dp_scyl = -1;
750 	    partp->dp_ssect = -1;
751 	} else {
752 	    partp->dp_shd = partp->dp_start % dos_cylsecs / dos_sectors;
753 	    partp->dp_scyl = DOSCYL(cy);
754 	    partp->dp_ssect = DOSSECT(sec, cy);
755 	}
756 
757 	/* End c/h/s. */
758 	end = partp->dp_start + partp->dp_size - 1;
759 	cy = end / dos_cylsecs;
760 	sec = end % dos_sectors + 1;
761 	if (cy > MAXCYL && C_flag == 0) {
762 	    printf("Warning: ending cylinder wraps, using all 1's\n");
763 	    partp->dp_ehd = -1;
764 	    partp->dp_ecyl = -1;
765 	    partp->dp_esect = -1;
766 	} else {
767 	    partp->dp_ehd = end % dos_cylsecs / dos_sectors;
768 	    partp->dp_ecyl = DOSCYL(cy);
769 	    partp->dp_esect = DOSSECT(sec, cy);
770 	}
771 }
772 
773 static void
774 erase_partition(int i)
775 {
776 	struct	  dos_partition *partp;
777 	off_t ioarg[2];
778 
779 	char sysctl_name[64];
780 	int trim_enabled = 0;
781 	size_t olen = sizeof(trim_enabled);
782 	char *dev_name = strdup(disk);
783 
784 	dev_name = strtok(dev_name + strlen("/dev/da"),"s");
785 	sprintf(sysctl_name, "kern.cam.da.%s.trim_enabled", dev_name);
786 	if (sysctlbyname(sysctl_name, &trim_enabled, &olen, NULL, 0) < 0) {
787 		printf("Device:%s does not support the TRIM command\n", disk);
788 		usage();
789 	}
790 	if (!trim_enabled) {
791 		printf("Erase device option selected, but sysctl (%s) "
792 		    "is not enabled\n",sysctl_name);
793 		usage();
794 	}
795 	partp = ((struct dos_partition *) &mboot.parts) + i;
796 	printf("erase sectors:%u %u\n",
797 	    partp->dp_start,
798 	    partp->dp_size);
799 
800 	/* Trim the Device */
801 	ioarg[0] = partp->dp_start;
802 	ioarg[0] *=secsize;
803 	ioarg[1] = partp->dp_size;
804 	ioarg[1] *=secsize;
805 
806 	if (ioctl(fd, IOCTLTRIM, ioarg) < 0) {
807 		printf("Device trim failed\n");
808 		usage ();
809 	}
810 }
811 
812 	/* Getting device status */
813 
814 static int
815 open_disk(void)
816 {
817 	struct stat 	st;
818 
819 	if (stat(disk, &st) == -1) {
820 		if (errno == ENOENT)
821 			return -2;
822 		warnx("can't get file status of %s", disk);
823 		return -1;
824 	}
825 	if (!(st.st_mode & S_IFCHR) && p_flag == 0)
826 		warnx("device %s is not character special", disk);
827 	if ((fd = open(disk,
828 	    a_flag || I_flag || B_flag || u_flag ? O_RDWR : O_RDONLY)) == -1) {
829 		if (errno == ENXIO)
830 			return -2;
831 		warnx("can't open device %s", disk);
832 		return -1;
833 	}
834 	if (get_params() == -1) {
835 		warnx("can't get disk parameters on %s", disk);
836 		return -1;
837 	}
838 	return fd;
839 }
840 
841 static ssize_t
842 read_disk(off_t sector, void *buf)
843 {
844 	lseek(fd,(sector * 512), 0);
845 	if (secsize == 0)
846 		for(secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE; secsize *= 2)
847 			{
848 			/* try the read */
849 			int size = read(fd, buf, secsize);
850 			if (size == secsize)
851 				/* it worked so return */
852 				return secsize;
853 			}
854 	else
855 		return read(fd, buf, secsize);
856 
857 	/* we failed to read at any of the sizes */
858 	return -1;
859 }
860 
861 static ssize_t
862 write_disk(off_t sector, void *buf)
863 {
864 	lseek(fd,(sector * 512), 0);
865 	/* write out in the size that the read_disk found worked */
866 	return write(fd, buf, secsize);
867 }
868 
869 static int
870 get_params(void)
871 {
872     struct partinfo partinfo;	/* disk parameters */
873     struct stat st;
874 
875     /*
876      * NOTE: When faking up the CHS for a file image (e.g. for USB),
877      *	     we must use max values.  If we do not then an overflowed
878      *       cylinder count will, by convention, set the CHS fields to
879      *       all 1's.  The heads and sectors in the CHS fields will then
880      *       exceed the basic geometry which can cause BIOSes to brick.
881      */
882     if (ioctl(fd, DIOCGPART, &partinfo) == -1) {
883 	if (p_flag && fstat(fd, &st) == 0 && st.st_size) {
884 	    sectors = MAX_SECTORS_PER_TRACK;
885 	    heads = MAX_HEADS;
886 	    cylsecs = heads * sectors;
887 	    cyls = st.st_size / 512 / cylsecs;
888 	} else {
889 	    warnx("can't get disk parameters on %s; supplying dummy ones",
890 		  disk);
891 	    heads = 1;
892 	    cylsecs = heads * sectors;
893 	}
894     } else {
895 	cyls = partinfo.d_ncylinders;
896 	heads = partinfo.d_nheads;
897 	sectors = partinfo.d_secpertrack;
898 	cylsecs = heads * sectors;
899 	secsize = partinfo.media_blksize;
900     }
901     dos_cyls = cyls;
902     dos_heads = heads;
903     dos_sectors = sectors;
904     dos_cylsecs = cylsecs;
905     disksecs = (int64_t)cyls * heads * sectors;
906     return (disksecs);
907 }
908 
909 
910 static int
911 read_s0(void)
912 {
913 	mboot.bootinst_size = secsize;
914 	if (mboot.bootinst != NULL)
915 		free(mboot.bootinst);
916 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
917 		warnx("unable to allocate buffer to read fdisk "
918 		      "partition table");
919 		return -1;
920 	}
921 	if (read_disk(0, mboot.bootinst) == -1) {
922 		warnx("can't read fdisk partition table");
923 		return -1;
924 	}
925 	if (*(uint16_t *)&mboot.bootinst[DOSMAGICOFFSET] != BOOT_MAGIC) {
926 		warnx("invalid fdisk partition table found");
927 		/* So should we initialize things */
928 		return -1;
929 	}
930 	memcpy(mboot.parts, &mboot.bootinst[DOSPARTOFF], sizeof(mboot.parts));
931 	return 0;
932 }
933 
934 static int
935 write_s0(void)
936 {
937 #ifdef NOT_NOW
938 	int	flag = 1;
939 #endif
940 	int	sector;
941 
942 	memcpy(&mboot.bootinst[DOSPARTOFF], mboot.parts, sizeof(mboot.parts));
943 	/*
944 	 * write enable label sector before write (if necessary),
945 	 * disable after writing.
946 	 * needed if the disklabel protected area also protects
947 	 * sector 0. (e.g. empty disk)
948 	 */
949 #ifdef NOT_NOW
950 	if (ioctl(fd, DIOCWLABEL, &flag) < 0)
951 		warn("ioctl DIOCWLABEL");
952 #endif
953 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
954 		if (write_disk(sector,
955 			       &mboot.bootinst[sector * secsize]) == -1) {
956 			warn("can't write fdisk partition table");
957 #ifdef NOT_NOW
958 			flag = 0;
959 			ioctl(fd, DIOCWLABEL, &flag);
960 #endif
961 			return -1;
962 		}
963 #ifdef NOT_NOW
964 	flag = 0;
965 	ioctl(fd, DIOCWLABEL, &flag);
966 #endif
967 	return(0);
968 }
969 
970 
971 static int
972 ok(const char *str)
973 {
974 	printf("%s [n] ", str);
975 	fflush(stdout);
976 	if (fgets(lbuf, LBUF, stdin) == NULL)
977 		exit(1);
978 	lbuf[strlen(lbuf)-1] = 0;
979 
980 	if (*lbuf &&
981 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
982 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
983 		return 1;
984 	else
985 		return 0;
986 }
987 
988 static int
989 decimal(const char *str, int *num, int deflt)
990 {
991 	int acc = 0, c;
992 	char *cp;
993 
994 	while (1) {
995 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
996 		fflush(stdout);
997 		if (fgets(lbuf, LBUF, stdin) == NULL)
998 			exit(1);
999 		lbuf[strlen(lbuf)-1] = 0;
1000 
1001 		if (!*lbuf)
1002 			return 0;
1003 
1004 		cp = lbuf;
1005 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
1006 		if (!c)
1007 			return 0;
1008 		while ((c = *cp++)) {
1009 			if (c <= '9' && c >= '0')
1010 				acc = acc * 10 + c - '0';
1011 			else
1012 				break;
1013 		}
1014 		if (c == ' ' || c == '\t')
1015 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
1016 		if (!c) {
1017 			*num = acc;
1018 			return 1;
1019 		} else
1020 			printf("%s is an invalid decimal number.  Try again.\n",
1021 				lbuf);
1022 	}
1023 
1024 }
1025 
1026 static const char *
1027 get_type(int type)
1028 {
1029 	int	numentries = (sizeof(part_types)/sizeof(struct part_type));
1030 	int	counter = 0;
1031 	struct	part_type *ptr = part_types;
1032 
1033 
1034 	while(counter < numentries)
1035 	{
1036 		if (ptr->type == type)
1037 		{
1038 			return(ptr->name);
1039 		}
1040 		ptr++;
1041 		counter++;
1042 	}
1043 	return("unknown");
1044 }
1045 
1046 
1047 static void
1048 parse_config_line(char *line, CMD *command)
1049 {
1050     char	*cp, *end;
1051 
1052     cp = line;
1053     while (1)	/* dirty trick used to insure one exit point for this
1054 		   function */
1055     {
1056 	memset(command, 0, sizeof(*command));
1057 
1058 	while (isspace(*cp)) ++cp;
1059 	if (*cp == '\0' || *cp == '#')
1060 	{
1061 	    break;
1062 	}
1063 	command->cmd = *cp++;
1064 
1065 	/*
1066 	 * Parse args
1067 	 */
1068 	while (1)
1069 	{
1070 	    while (isspace(*cp)) ++cp;
1071 	    if (*cp == '#')
1072 	    {
1073 		break;		/* found comment */
1074 	    }
1075 	    if (isalpha(*cp))
1076 	    {
1077 		command->args[command->n_args].argtype = *cp++;
1078 	    }
1079 	    if (!isdigit(*cp))
1080 	    {
1081 		break;		/* assume end of line */
1082 	    }
1083 	    end = NULL;
1084 	    command->args[command->n_args].arg_val = strtoll(cp, &end, 0);
1085 	    if (cp == end)
1086 	    {
1087 		break;		/* couldn't parse number */
1088 	    }
1089 	    cp = end;
1090 	    command->n_args++;
1091 	}
1092 	break;
1093     }
1094 }
1095 
1096 
1097 static int
1098 process_geometry(CMD *command)
1099 {
1100     int		status = 1, i;
1101 
1102     while (1)
1103     {
1104 	geom_processed = 1;
1105 	if (part_processed)
1106 	{
1107 	    warnx(
1108 	"ERROR line %d: the geometry specification line must occur before\n\
1109     all partition specifications",
1110 		    current_line_number);
1111 	    status = 0;
1112 	    break;
1113 	}
1114 	if (command->n_args != 3)
1115 	{
1116 	    warnx("ERROR line %d: incorrect number of geometry args",
1117 		    current_line_number);
1118 	    status = 0;
1119 	    break;
1120 	}
1121 	dos_cyls = -1;
1122 	dos_heads = -1;
1123 	dos_sectors = -1;
1124 	for (i = 0; i < 3; ++i)
1125 	{
1126 	    switch (command->args[i].argtype)
1127 	    {
1128 	    case 'c':
1129 		dos_cyls = command->args[i].arg_val;
1130 		break;
1131 	    case 'h':
1132 		dos_heads = command->args[i].arg_val;
1133 		break;
1134 	    case 's':
1135 		dos_sectors = command->args[i].arg_val;
1136 		break;
1137 	    default:
1138 		warnx(
1139 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1140 			current_line_number, command->args[i].argtype,
1141 			command->args[i].argtype);
1142 		status = 0;
1143 		break;
1144 	    }
1145 	}
1146 	if (status == 0)
1147 	{
1148 	    break;
1149 	}
1150 
1151 	dos_cylsecs = dos_heads * dos_sectors;
1152 
1153 	/*
1154 	 * Do sanity checks on parameter values
1155 	 */
1156 	if (dos_cyls < 0)
1157 	{
1158 	    warnx("ERROR line %d: number of cylinders not specified",
1159 		    current_line_number);
1160 	    status = 0;
1161 	}
1162 	if (dos_cyls == 0 || dos_cyls > 1024)
1163 	{
1164 	    warnx(
1165 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1166     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1167     is dedicated to DragonFly)",
1168 		    current_line_number, dos_cyls);
1169 	}
1170 
1171 	if (dos_heads < 0)
1172 	{
1173 	    warnx("ERROR line %d: number of heads not specified",
1174 		    current_line_number);
1175 	    status = 0;
1176 	}
1177 	else if (dos_heads < 1 || dos_heads > 256)
1178 	{
1179 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1180 		    current_line_number);
1181 	    status = 0;
1182 	}
1183 
1184 	if (dos_sectors < 0)
1185 	{
1186 	    warnx("ERROR line %d: number of sectors not specified",
1187 		    current_line_number);
1188 	    status = 0;
1189 	}
1190 	else if (dos_sectors < MIN_SECTORS_PER_TRACK || dos_sectors > MAX_SECTORS_PER_TRACK)
1191 	{
1192 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1193 		    current_line_number);
1194 	    status = 0;
1195 	}
1196 
1197 	break;
1198     }
1199     return (status);
1200 }
1201 
1202 
1203 static int
1204 process_partition(CMD *command)
1205 {
1206     int				status = 0, part;
1207     uint32_t			prev_head_boundary, prev_cyl_boundary;
1208     uint32_t			adj_size, max_end;
1209     struct dos_partition	*partp;
1210 
1211     while (1)
1212     {
1213 	part_processed = 1;
1214 	if (command->n_args != 4)
1215 	{
1216 	    warnx("ERROR line %d: incorrect number of partition args",
1217 		    current_line_number);
1218 	    break;
1219 	}
1220 	part = command->args[0].arg_val;
1221 	if (part < 1 || part > 4)
1222 	{
1223 	    warnx("ERROR line %d: invalid partition number %d",
1224 		    current_line_number, part);
1225 	    break;
1226 	}
1227 	partp = ((struct dos_partition *) &mboot.parts) + part - 1;
1228 	bzero((char *)partp, sizeof (struct dos_partition));
1229 	partp->dp_typ = command->args[1].arg_val;
1230 	partp->dp_start = command->args[2].arg_val;
1231 	partp->dp_size = command->args[3].arg_val;
1232 	max_end = partp->dp_start + partp->dp_size;
1233 
1234 	if (partp->dp_typ == 0)
1235 	{
1236 	    /*
1237 	     * Get out, the partition is marked as unused.
1238 	     */
1239 	    /*
1240 	     * Insure that it's unused.
1241 	     */
1242 	    bzero((char *)partp, sizeof (struct dos_partition));
1243 	    status = 1;
1244 	    break;
1245 	}
1246 
1247 	/*
1248 	 * Adjust start upwards, if necessary, to fall on an head boundary.
1249 	 */
1250 	if (partp->dp_start % dos_sectors != 0)
1251 	{
1252 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1253 	    if (max_end < (uint32_t)dos_sectors ||
1254 		prev_head_boundary > max_end - dos_sectors)
1255 	    {
1256 		/*
1257 		 * Can't go past end of partition
1258 		 */
1259 		warnx(
1260 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1261     a head boundary",
1262 			current_line_number, part);
1263 		break;
1264 	    }
1265 	    warnx(
1266 	"WARNING: adjusting start offset of partition %d\n\
1267     from %u to %u, to fall on a head boundary",
1268 		    part, (u_int)partp->dp_start,
1269 		    (u_int)(prev_head_boundary + dos_sectors));
1270 	    partp->dp_start = prev_head_boundary + dos_sectors;
1271 	}
1272 
1273 	/*
1274 	 * Adjust size downwards, if necessary, to fall on a cylinder
1275 	 * boundary.
1276 	 */
1277 	prev_cyl_boundary =
1278 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1279 	if (prev_cyl_boundary > partp->dp_start)
1280 	    adj_size = prev_cyl_boundary - partp->dp_start;
1281 	else
1282 	{
1283 	    warnx(
1284 	"ERROR: could not adjust partition to start on a head boundary\n\
1285     and end on a cylinder boundary.");
1286 	    return (0);
1287 	}
1288 	if (adj_size != partp->dp_size)
1289 	{
1290 	    warnx(
1291 	"WARNING: adjusting size of partition %d from %u to %u\n\
1292     to end on a cylinder boundary",
1293 		    part, (u_int)partp->dp_size, (u_int)adj_size);
1294 	    partp->dp_size = adj_size;
1295 	}
1296 	if (partp->dp_size == 0)
1297 	{
1298 	    warnx("ERROR line %d: size of partition %d is zero",
1299 		    current_line_number, part);
1300 	    break;
1301 	}
1302 
1303 	dos(partp);
1304 	status = 1;
1305 	break;
1306     }
1307     return (status);
1308 }
1309 
1310 
1311 static int
1312 process_active(CMD *command)
1313 {
1314     int				status = 0, part, i;
1315     struct dos_partition	*partp;
1316 
1317     while (1)
1318     {
1319 	active_processed = 1;
1320 	if (command->n_args != 1)
1321 	{
1322 	    warnx("ERROR line %d: incorrect number of active args",
1323 		    current_line_number);
1324 	    status = 0;
1325 	    break;
1326 	}
1327 	part = command->args[0].arg_val;
1328 	if (part < 1 || part > 4)
1329 	{
1330 	    warnx("ERROR line %d: invalid partition number %d",
1331 		    current_line_number, part);
1332 	    break;
1333 	}
1334 	/*
1335 	 * Reset active partition
1336 	 */
1337 	partp = ((struct dos_partition *) &mboot.parts);
1338 	for (i = 0; i < NDOSPART; i++)
1339 	    partp[i].dp_flag = 0;
1340 	partp[part-1].dp_flag = ACTIVE;
1341 
1342 	status = 1;
1343 	break;
1344     }
1345     return (status);
1346 }
1347 
1348 
1349 static int
1350 process_line(char *line)
1351 {
1352     CMD		command;
1353     int		status = 1;
1354 
1355     while (1)
1356     {
1357 	parse_config_line(line, &command);
1358 	switch (command.cmd)
1359 	{
1360 	case 0:
1361 	    /*
1362 	     * Comment or blank line
1363 	     */
1364 	    break;
1365 	case 'g':
1366 	    /*
1367 	     * Set geometry
1368 	     */
1369 	    status = process_geometry(&command);
1370 	    break;
1371 	case 'p':
1372 	    status = process_partition(&command);
1373 	    break;
1374 	case 'a':
1375 	    status = process_active(&command);
1376 	    break;
1377 	default:
1378 	    status = 0;
1379 	    break;
1380 	}
1381 	break;
1382     }
1383     return (status);
1384 }
1385 
1386 
1387 static int
1388 read_config(char *config_file)
1389 {
1390     FILE	*fp = NULL;
1391     int		status = 1;
1392     char	buf[1010];
1393 
1394     while (1)	/* dirty trick used to insure one exit point for this
1395 		   function */
1396     {
1397 	if (strcmp(config_file, "-") != 0)
1398 	{
1399 	    /*
1400 	     * We're not reading from stdin
1401 	     */
1402 	    if ((fp = fopen(config_file, "r")) == NULL)
1403 	    {
1404 		status = 0;
1405 		break;
1406 	    }
1407 	}
1408 	else
1409 	{
1410 	    fp = stdin;
1411 	}
1412 	current_line_number = 0;
1413 	while (!feof(fp))
1414 	{
1415 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1416 	    {
1417 		break;
1418 	    }
1419 	    ++current_line_number;
1420 	    status = process_line(buf);
1421 	    if (status == 0)
1422 	    {
1423 		break;
1424 	    }
1425 	}
1426 	break;
1427     }
1428     if (fp)
1429     {
1430 	/*
1431 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1432 	 */
1433 	fclose(fp);
1434     }
1435     return (status);
1436 }
1437 
1438 
1439 static void
1440 reset_boot(void)
1441 {
1442     int				i;
1443     struct dos_partition	*partp;
1444 
1445     init_boot();
1446     for (i = 0; i < 4; ++i)
1447     {
1448 	partp = ((struct dos_partition *) &mboot.parts) + i;
1449 	bzero((char *)partp, sizeof (struct dos_partition));
1450     }
1451 }
1452 
1453 static int
1454 sanitize_partition(struct dos_partition *partp)
1455 {
1456     uint32_t			prev_head_boundary, prev_cyl_boundary;
1457     uint32_t			max_end, size, start;
1458 
1459     start = partp->dp_start;
1460     size = partp->dp_size;
1461     max_end = start + size;
1462     /* Only allow a zero size if the partition is being marked unused. */
1463     if (size == 0) {
1464 	if (start == 0 && partp->dp_typ == 0)
1465 	    return (1);
1466 	warnx("ERROR: size of partition is zero");
1467 	return (0);
1468     }
1469     /* Return if no adjustment is necessary. */
1470     if (start % dos_sectors == 0 && (start + size) % dos_sectors == 0)
1471 	return (1);
1472 
1473     if (start == 0) {
1474 	    warnx("WARNING: partition overlaps with partition table");
1475 	    if (ok("Correct this automatically?"))
1476 		    start = dos_sectors;
1477     }
1478     if (start % dos_sectors != 0)
1479 	warnx("WARNING: partition does not start on a head boundary");
1480     if ((start  +size) % dos_sectors != 0)
1481 	warnx("WARNING: partition does not end on a cylinder boundary");
1482     warnx("WARNING: this may confuse the BIOS or some operating systems");
1483     if (!ok("Correct this automatically?"))
1484 	return (1);
1485 
1486     /*
1487      * Adjust start upwards, if necessary, to fall on an head boundary.
1488      */
1489     if (start % dos_sectors != 0) {
1490 	prev_head_boundary = start / dos_sectors * dos_sectors;
1491 	if (max_end < (uint32_t)dos_sectors ||
1492 	    prev_head_boundary >= max_end - dos_sectors) {
1493 	    /*
1494 	     * Can't go past end of partition
1495 	     */
1496 	    warnx(
1497     "ERROR: unable to adjust start of partition to fall on a head boundary");
1498 	    return (0);
1499         }
1500 	start = prev_head_boundary + dos_sectors;
1501     }
1502 
1503     /*
1504      * Adjust size downwards, if necessary, to fall on a cylinder
1505      * boundary.
1506      */
1507     prev_cyl_boundary = ((start + size) / dos_cylsecs) * dos_cylsecs;
1508     if (prev_cyl_boundary > start)
1509 	size = prev_cyl_boundary - start;
1510     else {
1511 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1512     and end on a cylinder boundary.");
1513 	return (0);
1514     }
1515 
1516     /* Finally, commit any changes to partp and return. */
1517     if (start != partp->dp_start) {
1518 	warnx("WARNING: adjusting start offset of partition to %u",
1519 	    (u_int)start);
1520 	partp->dp_start = start;
1521     }
1522     if (size != partp->dp_size) {
1523 	warnx("WARNING: adjusting size of partition to %u", (u_int)size);
1524 	partp->dp_size = size;
1525     }
1526 
1527     return (1);
1528 }
1529