xref: /freebsd/sbin/newfs_msdos/mkfs_msdos.c (revision 13ea0450a9c8742119d36f3bf8f47accdce46e54)
1 /*
2  * Copyright (c) 1998 Robert Nordier
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
21  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
23  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
25  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #ifndef lint
29 static const char rcsid[] =
30   "$FreeBSD$";
31 #endif /* not lint */
32 
33 #include <sys/param.h>
34 #include <sys/fdcio.h>
35 #include <sys/disk.h>
36 #include <sys/disklabel.h>
37 #include <sys/mount.h>
38 #include <sys/stat.h>
39 #include <sys/time.h>
40 
41 #include <ctype.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <inttypes.h>
46 #include <paths.h>
47 #include <signal.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <time.h>
52 #include <unistd.h>
53 
54 #include "mkfs_msdos.h"
55 
56 #define	MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
57 #define	BPN	  4		/* bits per nibble */
58 #define	NPB	  2		/* nibbles per byte */
59 
60 #define	DOSMAGIC  0xaa55	/* DOS magic number */
61 #define	MINBPS	  512		/* minimum bytes per sector */
62 #define	MAXSPC	  128		/* maximum sectors per cluster */
63 #define	MAXNFT	  16		/* maximum number of FATs */
64 #define	DEFBLK	  4096		/* default block size */
65 #define	DEFBLK16  2048		/* default block size FAT16 */
66 #define	DEFRDE	  512		/* default root directory entries */
67 #define	RESFTE	  2		/* reserved FAT entries */
68 #define	MINCLS12  1U		/* minimum FAT12 clusters */
69 #define	MINCLS16  0xff5U	/* minimum FAT16 clusters */
70 #define	MINCLS32  0xfff5U	/* minimum FAT32 clusters */
71 #define	MAXCLS12  0xff4U	/* maximum FAT12 clusters */
72 #define	MAXCLS16  0xfff4U	/* maximum FAT16 clusters */
73 #define	MAXCLS32  0xffffff4U	/* maximum FAT32 clusters */
74 
75 #define	mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
76 		      (fat) == 16 ? MINCLS16 :	\
77 				    MINCLS32)
78 
79 #define	maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
80 		      (fat) == 16 ? MAXCLS16 :	\
81 				    MAXCLS32)
82 
83 #define	mk1(p, x)				\
84     (p) = (u_int8_t)(x)
85 
86 #define	mk2(p, x)				\
87     (p)[0] = (u_int8_t)(x),			\
88     (p)[1] = (u_int8_t)((x) >> 010)
89 
90 #define	mk4(p, x)				\
91     (p)[0] = (u_int8_t)(x),			\
92     (p)[1] = (u_int8_t)((x) >> 010),		\
93     (p)[2] = (u_int8_t)((x) >> 020),		\
94     (p)[3] = (u_int8_t)((x) >> 030)
95 
96 struct bs {
97     u_int8_t bsJump[3];			/* bootstrap entry point */
98     u_int8_t bsOemName[8];		/* OEM name and version */
99 } __packed;
100 
101 struct bsbpb {
102     u_int8_t bpbBytesPerSec[2];		/* bytes per sector */
103     u_int8_t bpbSecPerClust;		/* sectors per cluster */
104     u_int8_t bpbResSectors[2];		/* reserved sectors */
105     u_int8_t bpbFATs;			/* number of FATs */
106     u_int8_t bpbRootDirEnts[2];		/* root directory entries */
107     u_int8_t bpbSectors[2];		/* total sectors */
108     u_int8_t bpbMedia;			/* media descriptor */
109     u_int8_t bpbFATsecs[2];		/* sectors per FAT */
110     u_int8_t bpbSecPerTrack[2];		/* sectors per track */
111     u_int8_t bpbHeads[2];		/* drive heads */
112     u_int8_t bpbHiddenSecs[4];		/* hidden sectors */
113     u_int8_t bpbHugeSectors[4];		/* big total sectors */
114 } __packed;
115 
116 struct bsxbpb {
117     u_int8_t bpbBigFATsecs[4];		/* big sectors per FAT */
118     u_int8_t bpbExtFlags[2];		/* FAT control flags */
119     u_int8_t bpbFSVers[2];		/* file system version */
120     u_int8_t bpbRootClust[4];		/* root directory start cluster */
121     u_int8_t bpbFSInfo[2];		/* file system info sector */
122     u_int8_t bpbBackup[2];		/* backup boot sector */
123     u_int8_t bpbReserved[12];		/* reserved */
124 } __packed;
125 
126 struct bsx {
127     u_int8_t exDriveNumber;		/* drive number */
128     u_int8_t exReserved1;		/* reserved */
129     u_int8_t exBootSignature;		/* extended boot signature */
130     u_int8_t exVolumeID[4];		/* volume ID number */
131     u_int8_t exVolumeLabel[11];		/* volume label */
132     u_int8_t exFileSysType[8];		/* file system type */
133 } __packed;
134 
135 struct de {
136     u_int8_t deName[11];		/* name and extension */
137     u_int8_t deAttributes;		/* attributes */
138     u_int8_t rsvd[10];			/* reserved */
139     u_int8_t deMTime[2];		/* last-modified time */
140     u_int8_t deMDate[2];		/* last-modified date */
141     u_int8_t deStartCluster[2];		/* starting cluster */
142     u_int8_t deFileSize[4];		/* size */
143 } __packed;
144 
145 struct bpb {
146     u_int bpbBytesPerSec;		/* bytes per sector */
147     u_int bpbSecPerClust;		/* sectors per cluster */
148     u_int bpbResSectors;		/* reserved sectors */
149     u_int bpbFATs;			/* number of FATs */
150     u_int bpbRootDirEnts;		/* root directory entries */
151     u_int bpbSectors;			/* total sectors */
152     u_int bpbMedia;			/* media descriptor */
153     u_int bpbFATsecs;			/* sectors per FAT */
154     u_int bpbSecPerTrack;		/* sectors per track */
155     u_int bpbHeads;			/* drive heads */
156     u_int bpbHiddenSecs;		/* hidden sectors */
157     u_int bpbHugeSectors; 		/* big total sectors */
158     u_int bpbBigFATsecs; 		/* big sectors per FAT */
159     u_int bpbRootClust; 		/* root directory start cluster */
160     u_int bpbFSInfo; 			/* file system info sector */
161     u_int bpbBackup; 			/* backup boot sector */
162 };
163 
164 #define	BPBGAP 0, 0, 0, 0, 0, 0
165 
166 static struct {
167     const char *name;
168     struct bpb bpb;
169 } const stdfmt[] = {
170     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
171     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
172     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
173     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
174     {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
175     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
176     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
177     {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
178     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
179     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
180 };
181 
182 static const u_int8_t bootcode[] = {
183     0xfa,			/* cli		    */
184     0x31, 0xc0, 		/* xor	   ax,ax    */
185     0x8e, 0xd0, 		/* mov	   ss,ax    */
186     0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
187     0xfb,			/* sti		    */
188     0x8e, 0xd8, 		/* mov	   ds,ax    */
189     0xe8, 0x00, 0x00,		/* call    $ + 3    */
190     0x5e,			/* pop	   si	    */
191     0x83, 0xc6, 0x19,		/* add	   si,+19h  */
192     0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
193     0xfc,			/* cld		    */
194     0xac,			/* lodsb	    */
195     0x84, 0xc0, 		/* test    al,al    */
196     0x74, 0x06, 		/* jz	   $ + 8    */
197     0xb4, 0x0e, 		/* mov	   ah,0eh   */
198     0xcd, 0x10, 		/* int	   10h	    */
199     0xeb, 0xf5, 		/* jmp	   $ - 9    */
200     0x30, 0xe4, 		/* xor	   ah,ah    */
201     0xcd, 0x16, 		/* int	   16h	    */
202     0xcd, 0x19, 		/* int	   19h	    */
203     0x0d, 0x0a,
204     'N', 'o', 'n', '-', 's', 'y', 's', 't',
205     'e', 'm', ' ', 'd', 'i', 's', 'k',
206     0x0d, 0x0a,
207     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
208     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
209     ' ', 'r', 'e', 'b', 'o', 'o', 't',
210     0x0d, 0x0a,
211     0
212 };
213 
214 static volatile sig_atomic_t got_siginfo;
215 static void infohandler(int);
216 
217 static int check_mounted(const char *, mode_t);
218 static int getstdfmt(const char *, struct bpb *);
219 static int getdiskinfo(int, const char *, const char *, int, struct bpb *);
220 static void print_bpb(struct bpb *);
221 static int ckgeom(const char *, u_int, const char *);
222 static void mklabel(u_int8_t *, const char *);
223 static int oklabel(const char *);
224 static void setstr(u_int8_t *, const char *, size_t);
225 
226 int
227 mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
228 {
229     char buf[MAXPATHLEN];
230     struct sigaction si_sa;
231     struct stat sb;
232     struct timeval tv;
233     struct bpb bpb;
234     struct tm *tm;
235     struct bs *bs;
236     struct bsbpb *bsbpb;
237     struct bsxbpb *bsxbpb;
238     struct bsx *bsx;
239     struct de *de;
240     u_int8_t *img;
241     const char *bname;
242     ssize_t n;
243     time_t now;
244     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
245     u_int extra_res, alignment, saved_x, attempts=0;
246     bool set_res, set_spf, set_spc;
247     int fd, fd1, rv;
248     struct msdos_options o = *op;
249 
250     img = NULL;
251     rv = -1;
252     fd = fd1 = -1;
253 
254     if (o.block_size && o.sectors_per_cluster) {
255 	warnx("Cannot specify both block size and sectors per cluster");
256 	goto done;
257     }
258     if (o.OEM_string && strlen(o.OEM_string) > 8) {
259 	warnx("%s: bad OEM string", o.OEM_string);
260 	goto done;
261     }
262     if (o.create_size) {
263 	if (o.no_create) {
264 	    warnx("create (-C) is incompatible with -N");
265 	    goto done;
266 	}
267 	fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
268 	if (fd == -1) {
269 	    warnx("failed to create %s", fname);
270 	    goto done;
271 	}
272 	if (ftruncate(fd, o.create_size)) {
273 	    warnx("failed to initialize %jd bytes", (intmax_t)o.create_size);
274 	    goto done;
275 	}
276     } else if ((fd = open(fname, o.no_create ? O_RDONLY : O_RDWR)) == -1) {
277 	warn("%s", fname);
278 	goto done;
279     }
280     if (fstat(fd, &sb)) {
281 	warn("%s", fname);
282 	goto done;
283     }
284     if (o.create_size) {
285 	if (!S_ISREG(sb.st_mode))
286 	    warnx("warning, %s is not a regular file", fname);
287     } else {
288 	if (!S_ISCHR(sb.st_mode))
289 	    warnx("warning, %s is not a character device", fname);
290     }
291     if (!o.no_create)
292 	if (check_mounted(fname, sb.st_mode) == -1)
293 	    goto done;
294     if (o.offset && o.offset != lseek(fd, o.offset, SEEK_SET)) {
295 	warnx("cannot seek to %jd", (intmax_t)o.offset);
296 	goto done;
297     }
298     memset(&bpb, 0, sizeof(bpb));
299     if (o.floppy) {
300 	if (getstdfmt(o.floppy, &bpb) == -1)
301 	    goto done;
302 	bpb.bpbHugeSectors = bpb.bpbSectors;
303 	bpb.bpbSectors = 0;
304 	bpb.bpbBigFATsecs = bpb.bpbFATsecs;
305 	bpb.bpbFATsecs = 0;
306     }
307     if (o.drive_heads)
308 	bpb.bpbHeads = o.drive_heads;
309     if (o.sectors_per_track)
310 	bpb.bpbSecPerTrack = o.sectors_per_track;
311     if (o.bytes_per_sector)
312 	bpb.bpbBytesPerSec = o.bytes_per_sector;
313     if (o.size)
314 	bpb.bpbHugeSectors = o.size;
315     if (o.hidden_sectors_set)
316 	bpb.bpbHiddenSecs = o.hidden_sectors;
317     if (!(o.floppy || (o.drive_heads && o.sectors_per_track &&
318 	o.bytes_per_sector && o.size && o.hidden_sectors_set))) {
319 	getdiskinfo(fd, fname, dtype, o.hidden_sectors_set, &bpb);
320 	bpb.bpbHugeSectors -= (o.offset / bpb.bpbBytesPerSec);
321 	if (bpb.bpbSecPerClust == 0) {	/* set defaults */
322 	    if (bpb.bpbHugeSectors <= 6000)	/* about 3MB -> 512 bytes */
323 		bpb.bpbSecPerClust = 1;
324 	    else if (bpb.bpbHugeSectors <= (1<<17)) /* 64M -> 4k */
325 		bpb.bpbSecPerClust = 8;
326 	    else if (bpb.bpbHugeSectors <= (1<<19)) /* 256M -> 8k */
327 		bpb.bpbSecPerClust = 16;
328 	    else if (bpb.bpbHugeSectors <= (1<<21)) /* 1G -> 16k */
329 		bpb.bpbSecPerClust = 32;
330 	    else
331 		bpb.bpbSecPerClust = 64;		/* otherwise 32k */
332 	}
333     }
334     if (!powerof2(bpb.bpbBytesPerSec)) {
335 	warnx("bytes/sector (%u) is not a power of 2", bpb.bpbBytesPerSec);
336 	goto done;
337     }
338     if (bpb.bpbBytesPerSec < MINBPS) {
339 	warnx("bytes/sector (%u) is too small; minimum is %u",
340 	     bpb.bpbBytesPerSec, MINBPS);
341 	goto done;
342     }
343 
344     if (o.volume_label && !oklabel(o.volume_label)) {
345 	warnx("%s: bad volume label", o.volume_label);
346 	goto done;
347     }
348     if (!(fat = o.fat_type)) {
349 	if (o.floppy)
350 	    fat = 12;
351 	else if (!o.directory_entries && (o.info_sector || o.backup_sector))
352 	    fat = 32;
353     }
354     if ((fat == 32 && o.directory_entries) || (fat != 32 && (o.info_sector || o.backup_sector))) {
355 	warnx("-%c is not a legal FAT%s option",
356 	     fat == 32 ? 'e' : o.info_sector ? 'i' : 'k',
357 	     fat == 32 ? "32" : "12/16");
358 	goto done;
359     }
360     if (o.floppy && fat == 32)
361 	bpb.bpbRootDirEnts = 0;
362     if (fat != 0 && fat != 12 && fat != 16 && fat != 32) {
363 	warnx("%d: bad FAT type", fat);
364 	goto done;
365     }
366 
367     if (o.block_size) {
368 	if (!powerof2(o.block_size)) {
369 	    warnx("block size (%u) is not a power of 2", o.block_size);
370 	    goto done;
371 	}
372 	if (o.block_size < bpb.bpbBytesPerSec) {
373 	    warnx("block size (%u) is too small; minimum is %u",
374 		 o.block_size, bpb.bpbBytesPerSec);
375 	    goto done;
376 	}
377 	if (o.block_size > bpb.bpbBytesPerSec * MAXSPC) {
378 	    warnx("block size (%u) is too large; maximum is %u",
379 		 o.block_size, bpb.bpbBytesPerSec * MAXSPC);
380 	    goto done;
381 	}
382 	bpb.bpbSecPerClust = o.block_size / bpb.bpbBytesPerSec;
383     }
384     if (o.sectors_per_cluster) {
385 	if (!powerof2(o.sectors_per_cluster)) {
386 	    warnx("sectors/cluster (%u) is not a power of 2",
387 		o.sectors_per_cluster);
388 	    goto done;
389 	}
390 	bpb.bpbSecPerClust = o.sectors_per_cluster;
391     }
392     if (o.reserved_sectors)
393 	bpb.bpbResSectors = o.reserved_sectors;
394     if (o.num_FAT) {
395 	if (o.num_FAT > MAXNFT) {
396 	    warnx("number of FATs (%u) is too large; maximum is %u",
397 		 o.num_FAT, MAXNFT);
398 	    goto done;
399 	}
400 	bpb.bpbFATs = o.num_FAT;
401     }
402     if (o.directory_entries)
403 	bpb.bpbRootDirEnts = o.directory_entries;
404     if (o.media_descriptor_set) {
405 	if (o.media_descriptor < 0xf0) {
406 	    warnx("illegal media descriptor (%#x)", o.media_descriptor);
407 	    goto done;
408 	}
409 	bpb.bpbMedia = o.media_descriptor;
410     }
411     if (o.sectors_per_fat)
412 	bpb.bpbBigFATsecs = o.sectors_per_fat;
413     if (o.info_sector)
414 	bpb.bpbFSInfo = o.info_sector;
415     if (o.backup_sector)
416 	bpb.bpbBackup = o.backup_sector;
417     bss = 1;
418     bname = NULL;
419     fd1 = -1;
420     if (o.bootstrap) {
421 	bname = o.bootstrap;
422 	if (!strchr(bname, '/')) {
423 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
424 	    if (!(bname = strdup(buf))) {
425 		warn(NULL);
426 		goto done;
427 	    }
428 	}
429 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb)) {
430 	    warn("%s", bname);
431 	    goto done;
432 	}
433 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bpbBytesPerSec ||
434 	    sb.st_size < bpb.bpbBytesPerSec ||
435 	    sb.st_size > bpb.bpbBytesPerSec * MAXU16) {
436 	    warnx("%s: inappropriate file type or format", bname);
437 	    goto done;
438 	}
439 	bss = sb.st_size / bpb.bpbBytesPerSec;
440     }
441     if (!bpb.bpbFATs)
442 	bpb.bpbFATs = 2;
443     if (!fat) {
444 	if (bpb.bpbHugeSectors < (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
445 	    howmany((RESFTE + (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1)) *
446 		(bpb.bpbSecPerClust ? 16 : 12) / BPN,
447 		bpb.bpbBytesPerSec * NPB) *
448 	    bpb.bpbFATs +
449 	    howmany(bpb.bpbRootDirEnts ? bpb.bpbRootDirEnts : DEFRDE,
450 		    bpb.bpbBytesPerSec / sizeof(struct de)) +
451 	    (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1) *
452 	    (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
453 	     howmany(DEFBLK, bpb.bpbBytesPerSec)))
454 	    fat = 12;
455 	else if (bpb.bpbRootDirEnts || bpb.bpbHugeSectors <
456 		 (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
457 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bpbBytesPerSec) *
458 		 bpb.bpbFATs +
459 		 howmany(DEFRDE, bpb.bpbBytesPerSec / sizeof(struct de)) +
460 		 (MAXCLS16 + 1) *
461 		 (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
462 		  howmany(8192, bpb.bpbBytesPerSec)))
463 	    fat = 16;
464 	else
465 	    fat = 32;
466     }
467     x = bss;
468     if (fat == 32) {
469 	if (!bpb.bpbFSInfo) {
470 	    if (x == MAXU16 || x == bpb.bpbBackup) {
471 		warnx("no room for info sector");
472 		goto done;
473 	    }
474 	    bpb.bpbFSInfo = x;
475 	}
476 	if (bpb.bpbFSInfo != MAXU16 && x <= bpb.bpbFSInfo)
477 	    x = bpb.bpbFSInfo + 1;
478 	if (!bpb.bpbBackup) {
479 	    if (x == MAXU16) {
480 		warnx("no room for backup sector");
481 		goto done;
482 	    }
483 	    bpb.bpbBackup = x;
484 	} else if (bpb.bpbBackup != MAXU16 && bpb.bpbBackup == bpb.bpbFSInfo) {
485 	    warnx("backup sector would overwrite info sector");
486 	    goto done;
487 	}
488 	if (bpb.bpbBackup != MAXU16 && x <= bpb.bpbBackup)
489 	    x = bpb.bpbBackup + 1;
490     }
491 
492     extra_res = 0;
493     alignment = 0;
494     set_res = (bpb.bpbResSectors == 0);
495     set_spf = (bpb.bpbBigFATsecs == 0);
496     set_spc = (bpb.bpbSecPerClust == 0);
497     saved_x = x;
498 
499     /*
500      * Attempt to align the root directory to cluster if o.align is set.
501      * This is done by padding with reserved blocks. Note that this can
502      * cause other factors to change, which can in turn change the alignment.
503      * This should take at most 2 iterations, as increasing the reserved
504      * amount may cause the FAT size to decrease by 1, requiring another
505      * bpbFATs reserved blocks. If bpbSecPerClust changes, it will
506      * be half of its previous size, and thus will not throw off alignment.
507      */
508     do {
509 	x = saved_x;
510 	if (set_res)
511 	    bpb.bpbResSectors = ((fat == 32) ?
512 		MAX(x, MAX(16384 / bpb.bpbBytesPerSec, 4)) : x) + extra_res;
513 	else if (bpb.bpbResSectors < x) {
514 	    warnx("too few reserved sectors (need %d have %d)", x,
515 		bpb.bpbResSectors);
516 	    goto done;
517 	}
518 	if (fat != 32 && !bpb.bpbRootDirEnts)
519 	    bpb.bpbRootDirEnts = DEFRDE;
520 	rds = howmany(bpb.bpbRootDirEnts,
521 	    bpb.bpbBytesPerSec / sizeof(struct de));
522 	if (set_spc) {
523 	    for (bpb.bpbSecPerClust = howmany(fat == 16 ? DEFBLK16 :
524 		    DEFBLK, bpb.bpbBytesPerSec);
525 		bpb.bpbSecPerClust < MAXSPC && (bpb.bpbResSectors +
526 		    howmany((RESFTE + maxcls(fat)) * (fat / BPN),
527 			bpb.bpbBytesPerSec * NPB) * bpb.bpbFATs +
528 		    rds +
529 		    (u_int64_t) (maxcls(fat) + 1) * bpb.bpbSecPerClust) <=
530 		    bpb.bpbHugeSectors;
531 		bpb.bpbSecPerClust <<= 1)
532 		    continue;
533 
534 	}
535 	if (fat != 32 && bpb.bpbBigFATsecs > MAXU16) {
536 	    warnx("too many sectors/FAT for FAT12/16");
537 	    goto done;
538 	}
539 	x1 = bpb.bpbResSectors + rds;
540 	x = bpb.bpbBigFATsecs ? bpb.bpbBigFATsecs : 1;
541 	if (x1 + (u_int64_t)x * bpb.bpbFATs > bpb.bpbHugeSectors) {
542 	    warnx("meta data exceeds file system size");
543 	    goto done;
544 	}
545 	x1 += x * bpb.bpbFATs;
546 	x = (u_int64_t)(bpb.bpbHugeSectors - x1) * bpb.bpbBytesPerSec * NPB /
547 	    (bpb.bpbSecPerClust * bpb.bpbBytesPerSec * NPB +
548 	    fat / BPN * bpb.bpbFATs);
549 	x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
550 	    bpb.bpbBytesPerSec * NPB);
551 	if (set_spf) {
552 	    if (bpb.bpbBigFATsecs == 0)
553 		bpb.bpbBigFATsecs = x2;
554 	    x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
555 	}
556 	if (set_res) {
557 	    /* attempt to align root directory */
558 	    alignment = (bpb.bpbResSectors + bpb.bpbBigFATsecs * bpb.bpbFATs) %
559 		bpb.bpbSecPerClust;
560 	    if (o.align)
561 		extra_res += bpb.bpbSecPerClust - alignment;
562 	}
563 	attempts++;
564     } while (o.align && alignment != 0 && attempts < 2);
565     if (o.align && alignment != 0)
566 	warnx("warning: Alignment failed.");
567 
568     cls = (bpb.bpbHugeSectors - x1) / bpb.bpbSecPerClust;
569     x = (u_int64_t)bpb.bpbBigFATsecs * bpb.bpbBytesPerSec * NPB / (fat / BPN) -
570 	RESFTE;
571     if (cls > x)
572 	cls = x;
573     if (bpb.bpbBigFATsecs < x2)
574 	warnx("warning: sectors/FAT limits file system to %u clusters",
575 	      cls);
576     if (cls < mincls(fat)) {
577 	warnx("%u clusters too few clusters for FAT%u, need %u", cls, fat,
578 	    mincls(fat));
579 	goto done;
580     }
581     if (cls > maxcls(fat)) {
582 	cls = maxcls(fat);
583 	bpb.bpbHugeSectors = x1 + (cls + 1) * bpb.bpbSecPerClust - 1;
584 	warnx("warning: FAT type limits file system to %u sectors",
585 	      bpb.bpbHugeSectors);
586     }
587     printf("%s: %u sector%s in %u FAT%u cluster%s "
588 	   "(%u bytes/cluster)\n", fname, cls * bpb.bpbSecPerClust,
589 	   cls * bpb.bpbSecPerClust == 1 ? "" : "s", cls, fat,
590 	   cls == 1 ? "" : "s", bpb.bpbBytesPerSec * bpb.bpbSecPerClust);
591     if (!bpb.bpbMedia)
592 	bpb.bpbMedia = !bpb.bpbHiddenSecs ? 0xf0 : 0xf8;
593     if (fat == 32)
594 	bpb.bpbRootClust = RESFTE;
595     if (bpb.bpbHugeSectors <= MAXU16) {
596 	bpb.bpbSectors = bpb.bpbHugeSectors;
597 	bpb.bpbHugeSectors = 0;
598     }
599     if (fat != 32) {
600 	bpb.bpbFATsecs = bpb.bpbBigFATsecs;
601 	bpb.bpbBigFATsecs = 0;
602     }
603     print_bpb(&bpb);
604     if (!o.no_create) {
605 	if (o.timestamp_set) {
606 	    tv.tv_sec = now = o.timestamp;
607 	    tv.tv_usec = 0;
608 	    tm = gmtime(&now);
609 	} else {
610 	    gettimeofday(&tv, NULL);
611 	    now = tv.tv_sec;
612 	    tm = localtime(&now);
613 	}
614 
615 
616 	if (!(img = malloc(bpb.bpbBytesPerSec))) {
617 	    warn(NULL);
618 	    goto done;
619 	}
620 	dir = bpb.bpbResSectors + (bpb.bpbFATsecs ? bpb.bpbFATsecs :
621 				   bpb.bpbBigFATsecs) * bpb.bpbFATs;
622 	memset(&si_sa, 0, sizeof(si_sa));
623 	si_sa.sa_handler = infohandler;
624 	if (sigaction(SIGINFO, &si_sa, NULL) == -1) {
625 	    warn("sigaction SIGINFO");
626 	    goto done;
627 	}
628 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.bpbSecPerClust : rds); lsn++) {
629 	    if (got_siginfo) {
630 		    fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
631 			fname, lsn,
632 			(dir + (fat == 32 ? bpb.bpbSecPerClust: rds)),
633 			(lsn * 100) / (dir +
634 			    (fat == 32 ? bpb.bpbSecPerClust: rds)));
635 		    got_siginfo = 0;
636 	    }
637 	    x = lsn;
638 	    if (o.bootstrap &&
639 		fat == 32 && bpb.bpbBackup != MAXU16 &&
640 		bss <= bpb.bpbBackup && x >= bpb.bpbBackup) {
641 		x -= bpb.bpbBackup;
642 		if (!x && lseek(fd1, o.offset, SEEK_SET)) {
643 		    warn("%s", bname);
644 		    goto done;
645 		}
646 	    }
647 	    if (o.bootstrap && x < bss) {
648 		if ((n = read(fd1, img, bpb.bpbBytesPerSec)) == -1) {
649 		    warn("%s", bname);
650 		    goto done;
651 		}
652 		if ((unsigned)n != bpb.bpbBytesPerSec) {
653 		    warnx("%s: can't read sector %u", bname, x);
654 		    goto done;
655 		}
656 	    } else
657 		memset(img, 0, bpb.bpbBytesPerSec);
658 	    if (!lsn ||
659 		(fat == 32 && bpb.bpbBackup != MAXU16 &&
660 		 lsn == bpb.bpbBackup)) {
661 		x1 = sizeof(struct bs);
662 		bsbpb = (struct bsbpb *)(img + x1);
663 		mk2(bsbpb->bpbBytesPerSec, bpb.bpbBytesPerSec);
664 		mk1(bsbpb->bpbSecPerClust, bpb.bpbSecPerClust);
665 		mk2(bsbpb->bpbResSectors, bpb.bpbResSectors);
666 		mk1(bsbpb->bpbFATs, bpb.bpbFATs);
667 		mk2(bsbpb->bpbRootDirEnts, bpb.bpbRootDirEnts);
668 		mk2(bsbpb->bpbSectors, bpb.bpbSectors);
669 		mk1(bsbpb->bpbMedia, bpb.bpbMedia);
670 		mk2(bsbpb->bpbFATsecs, bpb.bpbFATsecs);
671 		mk2(bsbpb->bpbSecPerTrack, bpb.bpbSecPerTrack);
672 		mk2(bsbpb->bpbHeads, bpb.bpbHeads);
673 		mk4(bsbpb->bpbHiddenSecs, bpb.bpbHiddenSecs);
674 		mk4(bsbpb->bpbHugeSectors, bpb.bpbHugeSectors);
675 		x1 += sizeof(struct bsbpb);
676 		if (fat == 32) {
677 		    bsxbpb = (struct bsxbpb *)(img + x1);
678 		    mk4(bsxbpb->bpbBigFATsecs, bpb.bpbBigFATsecs);
679 		    mk2(bsxbpb->bpbExtFlags, 0);
680 		    mk2(bsxbpb->bpbFSVers, 0);
681 		    mk4(bsxbpb->bpbRootClust, bpb.bpbRootClust);
682 		    mk2(bsxbpb->bpbFSInfo, bpb.bpbFSInfo);
683 		    mk2(bsxbpb->bpbBackup, bpb.bpbBackup);
684 		    x1 += sizeof(struct bsxbpb);
685 		}
686 		bsx = (struct bsx *)(img + x1);
687 		mk1(bsx->exBootSignature, 0x29);
688 		if (o.volume_id_set)
689 		    x = o.volume_id;
690 		else
691 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
692 			  (u_int)tm->tm_mday) +
693 			 ((u_int)tm->tm_sec << 8 |
694 			  (u_int)(tv.tv_usec / 10))) << 16 |
695 			((u_int)(1900 + tm->tm_year) +
696 			 ((u_int)tm->tm_hour << 8 |
697 			  (u_int)tm->tm_min));
698 		mk4(bsx->exVolumeID, x);
699 		mklabel(bsx->exVolumeLabel, o.volume_label ? o.volume_label : "NO NAME");
700 		snprintf(buf, sizeof(buf), "FAT%u", fat);
701 		setstr(bsx->exFileSysType, buf, sizeof(bsx->exFileSysType));
702 		if (!o.bootstrap) {
703 		    x1 += sizeof(struct bsx);
704 		    bs = (struct bs *)img;
705 		    mk1(bs->bsJump[0], 0xeb);
706 		    mk1(bs->bsJump[1], x1 - 2);
707 		    mk1(bs->bsJump[2], 0x90);
708 		    setstr(bs->bsOemName, o.OEM_string ? o.OEM_string : "BSD4.4  ",
709 			   sizeof(bs->bsOemName));
710 		    memcpy(img + x1, bootcode, sizeof(bootcode));
711 		    mk2(img + MINBPS - 2, DOSMAGIC);
712 		}
713 	    } else if (fat == 32 && bpb.bpbFSInfo != MAXU16 &&
714 		       (lsn == bpb.bpbFSInfo ||
715 			(bpb.bpbBackup != MAXU16 &&
716 			 lsn == bpb.bpbBackup + bpb.bpbFSInfo))) {
717 		mk4(img, 0x41615252);
718 		mk4(img + MINBPS - 28, 0x61417272);
719 		mk4(img + MINBPS - 24, 0xffffffff);
720 		mk4(img + MINBPS - 20, bpb.bpbRootClust);
721 		mk2(img + MINBPS - 2, DOSMAGIC);
722 	    } else if (lsn >= bpb.bpbResSectors && lsn < dir &&
723 		       !((lsn - bpb.bpbResSectors) %
724 			 (bpb.bpbFATsecs ? bpb.bpbFATsecs :
725 			  bpb.bpbBigFATsecs))) {
726 		mk1(img[0], bpb.bpbMedia);
727 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
728 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
729 	    } else if (lsn == dir && o.volume_label) {
730 		de = (struct de *)img;
731 		mklabel(de->deName, o.volume_label);
732 		mk1(de->deAttributes, 050);
733 		x = (u_int)tm->tm_hour << 11 |
734 		    (u_int)tm->tm_min << 5 |
735 		    (u_int)tm->tm_sec >> 1;
736 		mk2(de->deMTime, x);
737 		x = (u_int)(tm->tm_year - 80) << 9 |
738 		    (u_int)(tm->tm_mon + 1) << 5 |
739 		    (u_int)tm->tm_mday;
740 		mk2(de->deMDate, x);
741 	    }
742 	    if ((n = write(fd, img, bpb.bpbBytesPerSec)) == -1) {
743 		warn("%s", fname);
744 		goto done;
745 	    }
746 	    if ((unsigned)n != bpb.bpbBytesPerSec) {
747 		warnx("%s: can't write sector %u", fname, lsn);
748 		goto done;
749 	    }
750 	}
751     }
752     rv = 0;
753 done:
754     free(img);
755     if (fd != -1)
756 	    close(fd);
757     if (fd1 != -1)
758 	    close(fd1);
759 
760     return rv;
761 }
762 
763 /*
764  * return -1 with error if file system is mounted.
765  */
766 static int
767 check_mounted(const char *fname, mode_t mode)
768 {
769     struct statfs *mp;
770     const char *s1, *s2;
771     size_t len;
772     int n, r;
773 
774     if (!(n = getmntinfo(&mp, MNT_NOWAIT))) {
775 	warn("getmntinfo");
776 	return -1;
777     }
778     len = strlen(_PATH_DEV);
779     s1 = fname;
780     if (!strncmp(s1, _PATH_DEV, len))
781 	s1 += len;
782     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
783     for (; n--; mp++) {
784 	s2 = mp->f_mntfromname;
785 	if (!strncmp(s2, _PATH_DEV, len))
786 	    s2 += len;
787 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
788 	    !strcmp(s1, s2)) {
789 	    warnx("%s is mounted on %s", fname, mp->f_mntonname);
790 	    return -1;
791 	}
792     }
793     return 0;
794 }
795 
796 /*
797  * Get a standard format.
798  */
799 static int
800 getstdfmt(const char *fmt, struct bpb *bpb)
801 {
802     u_int x, i;
803 
804     x = nitems(stdfmt);
805     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
806     if (i == x) {
807 	warnx("%s: unknown standard format", fmt);
808 	return -1;
809     }
810     *bpb = stdfmt[i].bpb;
811     return 0;
812 }
813 
814 /*
815  * Get disk slice, partition, and geometry information.
816  */
817 static int
818 getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
819 	    struct bpb *bpb)
820 {
821     struct disklabel *lp, dlp;
822     struct fd_type type;
823     off_t ms, hs = 0;
824 
825     lp = NULL;
826 
827     /* If the user specified a disk type, try to use that */
828     if (dtype != NULL) {
829 	lp = getdiskbyname(dtype);
830     }
831 
832     /* Maybe it's a floppy drive */
833     if (lp == NULL) {
834 	if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
835 	    struct stat st;
836 
837 	    if (fstat(fd, &st))
838 		err(1, "cannot get disk size");
839 	    /* create a fake geometry for a file image */
840 	    ms = st.st_size;
841 	    dlp.d_secsize = 512;
842 	    dlp.d_nsectors = 63;
843 	    dlp.d_ntracks = 255;
844 	    dlp.d_secperunit = ms / dlp.d_secsize;
845 	    lp = &dlp;
846 	} else if (ioctl(fd, FD_GTYPE, &type) != -1) {
847 	    dlp.d_secsize = 128 << type.secsize;
848 	    dlp.d_nsectors = type.sectrac;
849 	    dlp.d_ntracks = type.heads;
850 	    dlp.d_secperunit = ms / dlp.d_secsize;
851 	    lp = &dlp;
852 	}
853     }
854 
855     /* Maybe it's a fixed drive */
856     if (lp == NULL) {
857 	if (bpb->bpbBytesPerSec)
858 	    dlp.d_secsize = bpb->bpbBytesPerSec;
859 	if (bpb->bpbBytesPerSec == 0 && ioctl(fd, DIOCGSECTORSIZE,
860 					      &dlp.d_secsize) == -1)
861 	    err(1, "cannot get sector size");
862 
863 	dlp.d_secperunit = ms / dlp.d_secsize;
864 
865 	if (bpb->bpbSecPerTrack == 0 && ioctl(fd, DIOCGFWSECTORS,
866 					      &dlp.d_nsectors) == -1) {
867 	    warn("cannot get number of sectors per track");
868 	    dlp.d_nsectors = 63;
869 	}
870 	if (bpb->bpbHeads == 0 &&
871 	    ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
872 	    warn("cannot get number of heads");
873 	    if (dlp.d_secperunit <= 63*1*1024)
874 		dlp.d_ntracks = 1;
875 	    else if (dlp.d_secperunit <= 63*16*1024)
876 		dlp.d_ntracks = 16;
877 	    else
878 		dlp.d_ntracks = 255;
879 	}
880 
881 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
882 	lp = &dlp;
883     }
884 
885     if (bpb->bpbBytesPerSec == 0) {
886 	if (ckgeom(fname, lp->d_secsize, "bytes/sector") == -1)
887 	    return -1;
888 	bpb->bpbBytesPerSec = lp->d_secsize;
889     }
890     if (bpb->bpbSecPerTrack == 0) {
891 	if (ckgeom(fname, lp->d_nsectors, "sectors/track") == -1)
892 	    return -1;
893 	bpb->bpbSecPerTrack = lp->d_nsectors;
894     }
895     if (bpb->bpbHeads == 0) {
896 	if (ckgeom(fname, lp->d_ntracks, "drive heads") == -1)
897 	    return -1;
898 	bpb->bpbHeads = lp->d_ntracks;
899     }
900     if (bpb->bpbHugeSectors == 0)
901 	bpb->bpbHugeSectors = lp->d_secperunit;
902     if (bpb->bpbHiddenSecs == 0)
903 	bpb->bpbHiddenSecs = hs;
904     return 0;
905 }
906 
907 /*
908  * Print out BPB values.
909  */
910 static void
911 print_bpb(struct bpb *bpb)
912 {
913     printf("BytesPerSec=%u SecPerClust=%u ResSectors=%u FATs=%u",
914 	   bpb->bpbBytesPerSec, bpb->bpbSecPerClust, bpb->bpbResSectors,
915 	   bpb->bpbFATs);
916     if (bpb->bpbRootDirEnts)
917 	printf(" RootDirEnts=%u", bpb->bpbRootDirEnts);
918     if (bpb->bpbSectors)
919 	printf(" Sectors=%u", bpb->bpbSectors);
920     printf(" Media=%#x", bpb->bpbMedia);
921     if (bpb->bpbFATsecs)
922 	printf(" FATsecs=%u", bpb->bpbFATsecs);
923     printf(" SecPerTrack=%u Heads=%u HiddenSecs=%u", bpb->bpbSecPerTrack,
924 	   bpb->bpbHeads, bpb->bpbHiddenSecs);
925     if (bpb->bpbHugeSectors)
926 	printf(" HugeSectors=%u", bpb->bpbHugeSectors);
927     if (!bpb->bpbFATsecs) {
928 	printf(" FATsecs=%u RootCluster=%u", bpb->bpbBigFATsecs,
929 	       bpb->bpbRootClust);
930 	printf(" FSInfo=");
931 	printf(bpb->bpbFSInfo == MAXU16 ? "%#x" : "%u", bpb->bpbFSInfo);
932 	printf(" Backup=");
933 	printf(bpb->bpbBackup == MAXU16 ? "%#x" : "%u", bpb->bpbBackup);
934     }
935     printf("\n");
936 }
937 
938 /*
939  * Check a disk geometry value.
940  */
941 static int
942 ckgeom(const char *fname, u_int val, const char *msg)
943 {
944     if (!val) {
945 	warnx("%s: no default %s", fname, msg);
946 	return -1;
947     }
948     if (val > MAXU16) {
949 	warnx("%s: illegal %s %d", fname, msg, val);
950 	return -1;
951     }
952     return 0;
953 }
954 
955 /*
956  * Check a volume label.
957  */
958 static int
959 oklabel(const char *src)
960 {
961     int c, i;
962 
963     for (i = 0; i <= 11; i++) {
964 	c = (u_char)*src++;
965 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
966 	    break;
967     }
968     return i && !c;
969 }
970 
971 /*
972  * Make a volume label.
973  */
974 static void
975 mklabel(u_int8_t *dest, const char *src)
976 {
977     int c, i;
978 
979     for (i = 0; i < 11; i++) {
980 	c = *src ? toupper(*src++) : ' ';
981 	*dest++ = !i && c == '\xe5' ? 5 : c;
982     }
983 }
984 
985 /*
986  * Copy string, padding with spaces.
987  */
988 static void
989 setstr(u_int8_t *dest, const char *src, size_t len)
990 {
991     while (len--)
992 	*dest++ = *src ? *src++ : ' ';
993 }
994 
995 static void
996 infohandler(int sig __unused)
997 {
998 
999 	got_siginfo = 1;
1000 }
1001