xref: /freebsd/sbin/newfs_msdos/mkfs_msdos.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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     int fd, fd1, rv;
246     struct msdos_options o = *op;
247 
248     img = NULL;
249     rv = -1;
250 
251     if (o.block_size && o.sectors_per_cluster) {
252 	warnx("Cannot specify both block size and sectors per cluster");
253 	goto done;
254     }
255     if (o.OEM_string && strlen(o.OEM_string) > 8) {
256 	warnx("%s: bad OEM string", o.OEM_string);
257 	goto done;
258     }
259     if (o.create_size) {
260 	if (o.no_create) {
261 	    warnx("create (-C) is incompatible with -N");
262 	    goto done;
263 	}
264 	fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
265 	if (fd == -1) {
266 	    warnx("failed to create %s", fname);
267 	    goto done;
268 	}
269 	if (ftruncate(fd, o.create_size)) {
270 	    warnx("failed to initialize %jd bytes", (intmax_t)o.create_size);
271 	    goto done;
272 	}
273     } else if ((fd = open(fname, o.no_create ? O_RDONLY : O_RDWR)) == -1) {
274 	warn("%s", fname);
275 	goto done;
276     }
277     if (fstat(fd, &sb)) {
278 	warn("%s", fname);
279 	goto done;
280     }
281     if (o.create_size) {
282 	if (!S_ISREG(sb.st_mode))
283 	    warnx("warning, %s is not a regular file", fname);
284     } else {
285 	if (!S_ISCHR(sb.st_mode))
286 	    warnx("warning, %s is not a character device", fname);
287     }
288     if (!o.no_create)
289 	if (check_mounted(fname, sb.st_mode) == -1)
290 	    goto done;
291     if (o.offset && o.offset != lseek(fd, o.offset, SEEK_SET)) {
292 	warnx("cannot seek to %jd", (intmax_t)o.offset);
293 	goto done;
294     }
295     memset(&bpb, 0, sizeof(bpb));
296     if (o.floppy) {
297 	if (getstdfmt(o.floppy, &bpb) == -1)
298 	    goto done;
299 	bpb.bpbHugeSectors = bpb.bpbSectors;
300 	bpb.bpbSectors = 0;
301 	bpb.bpbBigFATsecs = bpb.bpbFATsecs;
302 	bpb.bpbFATsecs = 0;
303     }
304     if (o.drive_heads)
305 	bpb.bpbHeads = o.drive_heads;
306     if (o.sectors_per_track)
307 	bpb.bpbSecPerTrack = o.sectors_per_track;
308     if (o.bytes_per_sector)
309 	bpb.bpbBytesPerSec = o.bytes_per_sector;
310     if (o.size)
311 	bpb.bpbHugeSectors = o.size;
312     if (o.hidden_sectors_set)
313 	bpb.bpbHiddenSecs = o.hidden_sectors;
314     if (!(o.floppy || (o.drive_heads && o.sectors_per_track &&
315 	o.bytes_per_sector && o.size && o.hidden_sectors_set))) {
316 	off_t delta;
317 	getdiskinfo(fd, fname, dtype, o.hidden_sectors_set, &bpb);
318 	bpb.bpbHugeSectors -= (o.offset / bpb.bpbBytesPerSec);
319 	delta = bpb.bpbHugeSectors % bpb.bpbSecPerTrack;
320 	if (delta != 0) {
321 	    warnx("trim %d sectors to adjust to a multiple of %d",
322 		(int)delta, bpb.bpbSecPerTrack);
323 	    bpb.bpbHugeSectors -= delta;
324 	}
325 	if (bpb.bpbSecPerClust == 0) {	/* set defaults */
326 	    if (bpb.bpbHugeSectors <= 6000)	/* about 3MB -> 512 bytes */
327 		bpb.bpbSecPerClust = 1;
328 	    else if (bpb.bpbHugeSectors <= (1<<17)) /* 64M -> 4k */
329 		bpb.bpbSecPerClust = 8;
330 	    else if (bpb.bpbHugeSectors <= (1<<19)) /* 256M -> 8k */
331 		bpb.bpbSecPerClust = 16;
332 	    else if (bpb.bpbHugeSectors <= (1<<21)) /* 1G -> 16k */
333 		bpb.bpbSecPerClust = 32;
334 	    else
335 		bpb.bpbSecPerClust = 64;		/* otherwise 32k */
336 	}
337     }
338     if (!powerof2(bpb.bpbBytesPerSec)) {
339 	warnx("bytes/sector (%u) is not a power of 2", bpb.bpbBytesPerSec);
340 	goto done;
341     }
342     if (bpb.bpbBytesPerSec < MINBPS) {
343 	warnx("bytes/sector (%u) is too small; minimum is %u",
344 	     bpb.bpbBytesPerSec, MINBPS);
345 	goto done;
346     }
347 
348     if (o.volume_label && !oklabel(o.volume_label)) {
349 	warnx("%s: bad volume label", o.volume_label);
350 	goto done;
351     }
352     if (!(fat = o.fat_type)) {
353 	if (o.floppy)
354 	    fat = 12;
355 	else if (!o.directory_entries && (o.info_sector || o.backup_sector))
356 	    fat = 32;
357     }
358     if ((fat == 32 && o.directory_entries) || (fat != 32 && (o.info_sector || o.backup_sector))) {
359 	warnx("-%c is not a legal FAT%s option",
360 	     fat == 32 ? 'e' : o.info_sector ? 'i' : 'k',
361 	     fat == 32 ? "32" : "12/16");
362 	goto done;
363     }
364     if (o.floppy && fat == 32)
365 	bpb.bpbRootDirEnts = 0;
366     if (fat != 0 && fat != 12 && fat != 16 && fat != 32) {
367 	warnx("%d: bad FAT type", fat);
368 	goto done;
369     }
370 
371     if (o.block_size) {
372 	if (!powerof2(o.block_size)) {
373 	    warnx("block size (%u) is not a power of 2", o.block_size);
374 	    goto done;
375 	}
376 	if (o.block_size < bpb.bpbBytesPerSec) {
377 	    warnx("block size (%u) is too small; minimum is %u",
378 		 o.block_size, bpb.bpbBytesPerSec);
379 	    goto done;
380 	}
381 	if (o.block_size > bpb.bpbBytesPerSec * MAXSPC) {
382 	    warnx("block size (%u) is too large; maximum is %u",
383 		 o.block_size, bpb.bpbBytesPerSec * MAXSPC);
384 	    goto done;
385 	}
386 	bpb.bpbSecPerClust = o.block_size / bpb.bpbBytesPerSec;
387     }
388     if (o.sectors_per_cluster) {
389 	if (!powerof2(o.sectors_per_cluster)) {
390 	    warnx("sectors/cluster (%u) is not a power of 2",
391 		o.sectors_per_cluster);
392 	    goto done;
393 	}
394 	bpb.bpbSecPerClust = o.sectors_per_cluster;
395     }
396     if (o.reserved_sectors)
397 	bpb.bpbResSectors = o.reserved_sectors;
398     if (o.num_FAT) {
399 	if (o.num_FAT > MAXNFT) {
400 	    warnx("number of FATs (%u) is too large; maximum is %u",
401 		 o.num_FAT, MAXNFT);
402 	    goto done;
403 	}
404 	bpb.bpbFATs = o.num_FAT;
405     }
406     if (o.directory_entries)
407 	bpb.bpbRootDirEnts = o.directory_entries;
408     if (o.media_descriptor_set) {
409 	if (o.media_descriptor < 0xf0) {
410 	    warnx("illegal media descriptor (%#x)", o.media_descriptor);
411 	    goto done;
412 	}
413 	bpb.bpbMedia = o.media_descriptor;
414     }
415     if (o.sectors_per_fat)
416 	bpb.bpbBigFATsecs = o.sectors_per_fat;
417     if (o.info_sector)
418 	bpb.bpbFSInfo = o.info_sector;
419     if (o.backup_sector)
420 	bpb.bpbBackup = o.backup_sector;
421     bss = 1;
422     bname = NULL;
423     fd1 = -1;
424     if (o.bootstrap) {
425 	bname = o.bootstrap;
426 	if (!strchr(bname, '/')) {
427 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
428 	    if (!(bname = strdup(buf))) {
429 		warn(NULL);
430 		goto done;
431 	    }
432 	}
433 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb)) {
434 	    warn("%s", bname);
435 	    goto done;
436 	}
437 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bpbBytesPerSec ||
438 	    sb.st_size < bpb.bpbBytesPerSec ||
439 	    sb.st_size > bpb.bpbBytesPerSec * MAXU16) {
440 	    warnx("%s: inappropriate file type or format", bname);
441 	    goto done;
442 	}
443 	bss = sb.st_size / bpb.bpbBytesPerSec;
444     }
445     if (!bpb.bpbFATs)
446 	bpb.bpbFATs = 2;
447     if (!fat) {
448 	if (bpb.bpbHugeSectors < (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
449 	    howmany((RESFTE + (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1)) *
450 		(bpb.bpbSecPerClust ? 16 : 12) / BPN,
451 		bpb.bpbBytesPerSec * NPB) *
452 	    bpb.bpbFATs +
453 	    howmany(bpb.bpbRootDirEnts ? bpb.bpbRootDirEnts : DEFRDE,
454 		    bpb.bpbBytesPerSec / sizeof(struct de)) +
455 	    (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1) *
456 	    (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
457 	     howmany(DEFBLK, bpb.bpbBytesPerSec)))
458 	    fat = 12;
459 	else if (bpb.bpbRootDirEnts || bpb.bpbHugeSectors <
460 		 (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
461 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bpbBytesPerSec) *
462 		 bpb.bpbFATs +
463 		 howmany(DEFRDE, bpb.bpbBytesPerSec / sizeof(struct de)) +
464 		 (MAXCLS16 + 1) *
465 		 (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
466 		  howmany(8192, bpb.bpbBytesPerSec)))
467 	    fat = 16;
468 	else
469 	    fat = 32;
470     }
471     x = bss;
472     if (fat == 32) {
473 	if (!bpb.bpbFSInfo) {
474 	    if (x == MAXU16 || x == bpb.bpbBackup) {
475 		warnx("no room for info sector");
476 		goto done;
477 	    }
478 	    bpb.bpbFSInfo = x;
479 	}
480 	if (bpb.bpbFSInfo != MAXU16 && x <= bpb.bpbFSInfo)
481 	    x = bpb.bpbFSInfo + 1;
482 	if (!bpb.bpbBackup) {
483 	    if (x == MAXU16) {
484 		warnx("no room for backup sector");
485 		goto done;
486 	    }
487 	    bpb.bpbBackup = x;
488 	} else if (bpb.bpbBackup != MAXU16 && bpb.bpbBackup == bpb.bpbFSInfo) {
489 	    warnx("backup sector would overwrite info sector");
490 	    goto done;
491 	}
492 	if (bpb.bpbBackup != MAXU16 && x <= bpb.bpbBackup)
493 	    x = bpb.bpbBackup + 1;
494     }
495     if (!bpb.bpbResSectors)
496 	bpb.bpbResSectors = fat == 32 ?
497 	    MAX(x, MAX(16384 / bpb.bpbBytesPerSec, 4)) : x;
498     else if (bpb.bpbResSectors < x) {
499 	warnx("too few reserved sectors (need %d have %d)", x,
500 	     bpb.bpbResSectors);
501 	goto done;
502     }
503     if (fat != 32 && !bpb.bpbRootDirEnts)
504 	bpb.bpbRootDirEnts = DEFRDE;
505     rds = howmany(bpb.bpbRootDirEnts, bpb.bpbBytesPerSec / sizeof(struct de));
506     if (!bpb.bpbSecPerClust)
507 	for (bpb.bpbSecPerClust = howmany(fat == 16 ? DEFBLK16 :
508 					  DEFBLK, bpb.bpbBytesPerSec);
509 	     bpb.bpbSecPerClust < MAXSPC &&
510 	     bpb.bpbResSectors +
511 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
512 		     bpb.bpbBytesPerSec * NPB) *
513 	     bpb.bpbFATs +
514 	     rds +
515 	     (u_int64_t) (maxcls(fat) + 1) *
516 	     bpb.bpbSecPerClust <= bpb.bpbHugeSectors;
517 	     bpb.bpbSecPerClust <<= 1)
518 	    continue;
519     if (fat != 32 && bpb.bpbBigFATsecs > MAXU16) {
520 	warnx("too many sectors/FAT for FAT12/16");
521 	goto done;
522     }
523     x1 = bpb.bpbResSectors + rds;
524     x = bpb.bpbBigFATsecs ? bpb.bpbBigFATsecs : 1;
525     if (x1 + (u_int64_t)x * bpb.bpbFATs > bpb.bpbHugeSectors) {
526 	warnx("meta data exceeds file system size");
527 	goto done;
528     }
529     x1 += x * bpb.bpbFATs;
530     x = (u_int64_t)(bpb.bpbHugeSectors - x1) * bpb.bpbBytesPerSec * NPB /
531 	(bpb.bpbSecPerClust * bpb.bpbBytesPerSec * NPB + fat /
532 	 BPN * bpb.bpbFATs);
533     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
534 		 bpb.bpbBytesPerSec * NPB);
535     if (!bpb.bpbBigFATsecs) {
536 	bpb.bpbBigFATsecs = x2;
537 	x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
538     }
539     cls = (bpb.bpbHugeSectors - x1) / bpb.bpbSecPerClust;
540     x = (u_int64_t)bpb.bpbBigFATsecs * bpb.bpbBytesPerSec * NPB / (fat / BPN) -
541 	RESFTE;
542     if (cls > x)
543 	cls = x;
544     if (bpb.bpbBigFATsecs < x2)
545 	warnx("warning: sectors/FAT limits file system to %u clusters",
546 	      cls);
547     if (cls < mincls(fat)) {
548 	warnx("%u clusters too few clusters for FAT%u, need %u", cls, fat,
549 	    mincls(fat));
550 	goto done;
551     }
552     if (cls > maxcls(fat)) {
553 	cls = maxcls(fat);
554 	bpb.bpbHugeSectors = x1 + (cls + 1) * bpb.bpbSecPerClust - 1;
555 	warnx("warning: FAT type limits file system to %u sectors",
556 	      bpb.bpbHugeSectors);
557     }
558     printf("%s: %u sector%s in %u FAT%u cluster%s "
559 	   "(%u bytes/cluster)\n", fname, cls * bpb.bpbSecPerClust,
560 	   cls * bpb.bpbSecPerClust == 1 ? "" : "s", cls, fat,
561 	   cls == 1 ? "" : "s", bpb.bpbBytesPerSec * bpb.bpbSecPerClust);
562     if (!bpb.bpbMedia)
563 	bpb.bpbMedia = !bpb.bpbHiddenSecs ? 0xf0 : 0xf8;
564     if (fat == 32)
565 	bpb.bpbRootClust = RESFTE;
566     if (bpb.bpbHiddenSecs + bpb.bpbHugeSectors <= MAXU16) {
567 	bpb.bpbSectors = bpb.bpbHugeSectors;
568 	bpb.bpbHugeSectors = 0;
569     }
570     if (fat != 32) {
571 	bpb.bpbFATsecs = bpb.bpbBigFATsecs;
572 	bpb.bpbBigFATsecs = 0;
573     }
574     print_bpb(&bpb);
575     if (!o.no_create) {
576 	gettimeofday(&tv, NULL);
577 	now = tv.tv_sec;
578 	tm = localtime(&now);
579 	if (!(img = malloc(bpb.bpbBytesPerSec))) {
580 	    warn(NULL);
581 	    goto done;
582 	}
583 	dir = bpb.bpbResSectors + (bpb.bpbFATsecs ? bpb.bpbFATsecs :
584 				   bpb.bpbBigFATsecs) * bpb.bpbFATs;
585 	memset(&si_sa, 0, sizeof(si_sa));
586 	si_sa.sa_handler = infohandler;
587 	if (sigaction(SIGINFO, &si_sa, NULL) == -1) {
588 	    warn("sigaction SIGINFO");
589 	    goto done;
590 	}
591 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.bpbSecPerClust : rds); lsn++) {
592 	    if (got_siginfo) {
593 		    fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
594 			fname, lsn,
595 			(dir + (fat == 32 ? bpb.bpbSecPerClust: rds)),
596 			(lsn * 100) / (dir +
597 			    (fat == 32 ? bpb.bpbSecPerClust: rds)));
598 		    got_siginfo = 0;
599 	    }
600 	    x = lsn;
601 	    if (o.bootstrap &&
602 		fat == 32 && bpb.bpbBackup != MAXU16 &&
603 		bss <= bpb.bpbBackup && x >= bpb.bpbBackup) {
604 		x -= bpb.bpbBackup;
605 		if (!x && lseek(fd1, o.offset, SEEK_SET)) {
606 		    warn("%s", bname);
607 		    goto done;
608 		}
609 	    }
610 	    if (o.bootstrap && x < bss) {
611 		if ((n = read(fd1, img, bpb.bpbBytesPerSec)) == -1) {
612 		    warn("%s", bname);
613 		    goto done;
614 		}
615 		if ((unsigned)n != bpb.bpbBytesPerSec) {
616 		    warnx("%s: can't read sector %u", bname, x);
617 		    goto done;
618 		}
619 	    } else
620 		memset(img, 0, bpb.bpbBytesPerSec);
621 	    if (!lsn ||
622 		(fat == 32 && bpb.bpbBackup != MAXU16 &&
623 		 lsn == bpb.bpbBackup)) {
624 		x1 = sizeof(struct bs);
625 		bsbpb = (struct bsbpb *)(img + x1);
626 		mk2(bsbpb->bpbBytesPerSec, bpb.bpbBytesPerSec);
627 		mk1(bsbpb->bpbSecPerClust, bpb.bpbSecPerClust);
628 		mk2(bsbpb->bpbResSectors, bpb.bpbResSectors);
629 		mk1(bsbpb->bpbFATs, bpb.bpbFATs);
630 		mk2(bsbpb->bpbRootDirEnts, bpb.bpbRootDirEnts);
631 		mk2(bsbpb->bpbSectors, bpb.bpbSectors);
632 		mk1(bsbpb->bpbMedia, bpb.bpbMedia);
633 		mk2(bsbpb->bpbFATsecs, bpb.bpbFATsecs);
634 		mk2(bsbpb->bpbSecPerTrack, bpb.bpbSecPerTrack);
635 		mk2(bsbpb->bpbHeads, bpb.bpbHeads);
636 		mk4(bsbpb->bpbHiddenSecs, bpb.bpbHiddenSecs);
637 		mk4(bsbpb->bpbHugeSectors, bpb.bpbHugeSectors);
638 		x1 += sizeof(struct bsbpb);
639 		if (fat == 32) {
640 		    bsxbpb = (struct bsxbpb *)(img + x1);
641 		    mk4(bsxbpb->bpbBigFATsecs, bpb.bpbBigFATsecs);
642 		    mk2(bsxbpb->bpbExtFlags, 0);
643 		    mk2(bsxbpb->bpbFSVers, 0);
644 		    mk4(bsxbpb->bpbRootClust, bpb.bpbRootClust);
645 		    mk2(bsxbpb->bpbFSInfo, bpb.bpbFSInfo);
646 		    mk2(bsxbpb->bpbBackup, bpb.bpbBackup);
647 		    x1 += sizeof(struct bsxbpb);
648 		}
649 		bsx = (struct bsx *)(img + x1);
650 		mk1(bsx->exBootSignature, 0x29);
651 		if (o.volume_id_set)
652 		    x = o.volume_id;
653 		else
654 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
655 			  (u_int)tm->tm_mday) +
656 			 ((u_int)tm->tm_sec << 8 |
657 			  (u_int)(tv.tv_usec / 10))) << 16 |
658 			((u_int)(1900 + tm->tm_year) +
659 			 ((u_int)tm->tm_hour << 8 |
660 			  (u_int)tm->tm_min));
661 		mk4(bsx->exVolumeID, x);
662 		mklabel(bsx->exVolumeLabel, o.volume_label ? o.volume_label : "NO NAME");
663 		snprintf(buf, sizeof(buf), "FAT%u", fat);
664 		setstr(bsx->exFileSysType, buf, sizeof(bsx->exFileSysType));
665 		if (!o.bootstrap) {
666 		    x1 += sizeof(struct bsx);
667 		    bs = (struct bs *)img;
668 		    mk1(bs->bsJump[0], 0xeb);
669 		    mk1(bs->bsJump[1], x1 - 2);
670 		    mk1(bs->bsJump[2], 0x90);
671 		    setstr(bs->bsOemName, o.OEM_string ? o.OEM_string : "BSD4.4  ",
672 			   sizeof(bs->bsOemName));
673 		    memcpy(img + x1, bootcode, sizeof(bootcode));
674 		    mk2(img + MINBPS - 2, DOSMAGIC);
675 		}
676 	    } else if (fat == 32 && bpb.bpbFSInfo != MAXU16 &&
677 		       (lsn == bpb.bpbFSInfo ||
678 			(bpb.bpbBackup != MAXU16 &&
679 			 lsn == bpb.bpbBackup + bpb.bpbFSInfo))) {
680 		mk4(img, 0x41615252);
681 		mk4(img + MINBPS - 28, 0x61417272);
682 		mk4(img + MINBPS - 24, 0xffffffff);
683 		mk4(img + MINBPS - 20, bpb.bpbRootClust);
684 		mk2(img + MINBPS - 2, DOSMAGIC);
685 	    } else if (lsn >= bpb.bpbResSectors && lsn < dir &&
686 		       !((lsn - bpb.bpbResSectors) %
687 			 (bpb.bpbFATsecs ? bpb.bpbFATsecs :
688 			  bpb.bpbBigFATsecs))) {
689 		mk1(img[0], bpb.bpbMedia);
690 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
691 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
692 	    } else if (lsn == dir && o.volume_label) {
693 		de = (struct de *)img;
694 		mklabel(de->deName, o.volume_label);
695 		mk1(de->deAttributes, 050);
696 		x = (u_int)tm->tm_hour << 11 |
697 		    (u_int)tm->tm_min << 5 |
698 		    (u_int)tm->tm_sec >> 1;
699 		mk2(de->deMTime, x);
700 		x = (u_int)(tm->tm_year - 80) << 9 |
701 		    (u_int)(tm->tm_mon + 1) << 5 |
702 		    (u_int)tm->tm_mday;
703 		mk2(de->deMDate, x);
704 	    }
705 	    if ((n = write(fd, img, bpb.bpbBytesPerSec)) == -1) {
706 		warn("%s", fname);
707 		goto done;
708 	    }
709 	    if ((unsigned)n != bpb.bpbBytesPerSec) {
710 		warnx("%s: can't write sector %u", fname, lsn);
711 		goto done;
712 	    }
713 	}
714     }
715     rv = 0;
716 done:
717     free(img);
718 
719     return rv;
720 }
721 
722 /*
723  * return -1 with error if file system is mounted.
724  */
725 static int
726 check_mounted(const char *fname, mode_t mode)
727 {
728     struct statfs *mp;
729     const char *s1, *s2;
730     size_t len;
731     int n, r;
732 
733     if (!(n = getmntinfo(&mp, MNT_NOWAIT))) {
734 	warn("getmntinfo");
735 	return -1;
736     }
737     len = strlen(_PATH_DEV);
738     s1 = fname;
739     if (!strncmp(s1, _PATH_DEV, len))
740 	s1 += len;
741     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
742     for (; n--; mp++) {
743 	s2 = mp->f_mntfromname;
744 	if (!strncmp(s2, _PATH_DEV, len))
745 	    s2 += len;
746 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
747 	    !strcmp(s1, s2)) {
748 	    warnx("%s is mounted on %s", fname, mp->f_mntonname);
749 	    return -1;
750 	}
751     }
752     return 0;
753 }
754 
755 /*
756  * Get a standard format.
757  */
758 static int
759 getstdfmt(const char *fmt, struct bpb *bpb)
760 {
761     u_int x, i;
762 
763     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
764     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
765     if (i == x) {
766 	warnx("%s: unknown standard format", fmt);
767 	return -1;
768     }
769     *bpb = stdfmt[i].bpb;
770     return 0;
771 }
772 
773 /*
774  * Get disk slice, partition, and geometry information.
775  */
776 static int
777 getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
778 	    struct bpb *bpb)
779 {
780     struct disklabel *lp, dlp;
781     struct fd_type type;
782     off_t ms, hs = 0;
783 
784     lp = NULL;
785 
786     /* If the user specified a disk type, try to use that */
787     if (dtype != NULL) {
788 	lp = getdiskbyname(dtype);
789     }
790 
791     /* Maybe it's a floppy drive */
792     if (lp == NULL) {
793 	if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
794 	    struct stat st;
795 
796 	    if (fstat(fd, &st))
797 		err(1, "cannot get disk size");
798 	    /* create a fake geometry for a file image */
799 	    ms = st.st_size;
800 	    dlp.d_secsize = 512;
801 	    dlp.d_nsectors = 63;
802 	    dlp.d_ntracks = 255;
803 	    dlp.d_secperunit = ms / dlp.d_secsize;
804 	    lp = &dlp;
805 	} else if (ioctl(fd, FD_GTYPE, &type) != -1) {
806 	    dlp.d_secsize = 128 << type.secsize;
807 	    dlp.d_nsectors = type.sectrac;
808 	    dlp.d_ntracks = type.heads;
809 	    dlp.d_secperunit = ms / dlp.d_secsize;
810 	    lp = &dlp;
811 	}
812     }
813 
814     /* Maybe it's a fixed drive */
815     if (lp == NULL) {
816 	if (bpb->bpbBytesPerSec)
817 	    dlp.d_secsize = bpb->bpbBytesPerSec;
818 	if (bpb->bpbBytesPerSec == 0 && ioctl(fd, DIOCGSECTORSIZE,
819 					      &dlp.d_secsize) == -1)
820 	    err(1, "cannot get sector size");
821 
822 	dlp.d_secperunit = ms / dlp.d_secsize;
823 
824 	if (bpb->bpbSecPerTrack == 0 && ioctl(fd, DIOCGFWSECTORS,
825 					      &dlp.d_nsectors) == -1) {
826 	    warn("cannot get number of sectors per track");
827 	    dlp.d_nsectors = 63;
828 	}
829 	if (bpb->bpbHeads == 0 &&
830 	    ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
831 	    warn("cannot get number of heads");
832 	    if (dlp.d_secperunit <= 63*1*1024)
833 		dlp.d_ntracks = 1;
834 	    else if (dlp.d_secperunit <= 63*16*1024)
835 		dlp.d_ntracks = 16;
836 	    else
837 		dlp.d_ntracks = 255;
838 	}
839 
840 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
841 	lp = &dlp;
842     }
843 
844     if (bpb->bpbBytesPerSec == 0) {
845 	if (ckgeom(fname, lp->d_secsize, "bytes/sector") == -1)
846 	    return -1;
847 	bpb->bpbBytesPerSec = lp->d_secsize;
848     }
849     if (bpb->bpbSecPerTrack == 0) {
850 	if (ckgeom(fname, lp->d_nsectors, "sectors/track") == -1)
851 	    return -1;
852 	bpb->bpbSecPerTrack = lp->d_nsectors;
853     }
854     if (bpb->bpbHeads == 0) {
855 	if (ckgeom(fname, lp->d_ntracks, "drive heads") == -1)
856 	    return -1;
857 	bpb->bpbHeads = lp->d_ntracks;
858     }
859     if (bpb->bpbHugeSectors == 0)
860 	bpb->bpbHugeSectors = lp->d_secperunit;
861     if (bpb->bpbHiddenSecs == 0)
862 	bpb->bpbHiddenSecs = hs;
863     return 0;
864 }
865 
866 /*
867  * Print out BPB values.
868  */
869 static void
870 print_bpb(struct bpb *bpb)
871 {
872     printf("BytesPerSec=%u SecPerClust=%u ResSectors=%u FATs=%u",
873 	   bpb->bpbBytesPerSec, bpb->bpbSecPerClust, bpb->bpbResSectors,
874 	   bpb->bpbFATs);
875     if (bpb->bpbRootDirEnts)
876 	printf(" RootDirEnts=%u", bpb->bpbRootDirEnts);
877     if (bpb->bpbSectors)
878 	printf(" Sectors=%u", bpb->bpbSectors);
879     printf(" Media=%#x", bpb->bpbMedia);
880     if (bpb->bpbFATsecs)
881 	printf(" FATsecs=%u", bpb->bpbFATsecs);
882     printf(" SecPerTrack=%u Heads=%u HiddenSecs=%u", bpb->bpbSecPerTrack,
883 	   bpb->bpbHeads, bpb->bpbHiddenSecs);
884     if (bpb->bpbHugeSectors)
885 	printf(" HugeSectors=%u", bpb->bpbHugeSectors);
886     if (!bpb->bpbFATsecs) {
887 	printf(" FATsecs=%u RootCluster=%u", bpb->bpbBigFATsecs,
888 	       bpb->bpbRootClust);
889 	printf(" FSInfo=");
890 	printf(bpb->bpbFSInfo == MAXU16 ? "%#x" : "%u", bpb->bpbFSInfo);
891 	printf(" Backup=");
892 	printf(bpb->bpbBackup == MAXU16 ? "%#x" : "%u", bpb->bpbBackup);
893     }
894     printf("\n");
895 }
896 
897 /*
898  * Check a disk geometry value.
899  */
900 static int
901 ckgeom(const char *fname, u_int val, const char *msg)
902 {
903     if (!val) {
904 	warnx("%s: no default %s", fname, msg);
905 	return -1;
906     }
907     if (val > MAXU16) {
908 	warnx("%s: illegal %s %d", fname, msg, val);
909 	return -1;
910     }
911     return 0;
912 }
913 
914 /*
915  * Check a volume label.
916  */
917 static int
918 oklabel(const char *src)
919 {
920     int c, i;
921 
922     for (i = 0; i <= 11; i++) {
923 	c = (u_char)*src++;
924 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
925 	    break;
926     }
927     return i && !c;
928 }
929 
930 /*
931  * Make a volume label.
932  */
933 static void
934 mklabel(u_int8_t *dest, const char *src)
935 {
936     int c, i;
937 
938     for (i = 0; i < 11; i++) {
939 	c = *src ? toupper(*src++) : ' ';
940 	*dest++ = !i && c == '\xe5' ? 5 : c;
941     }
942 }
943 
944 /*
945  * Copy string, padding with spaces.
946  */
947 static void
948 setstr(u_int8_t *dest, const char *src, size_t len)
949 {
950     while (len--)
951 	*dest++ = *src ? *src++ : ' ';
952 }
953 
954 static void
955 infohandler(int sig __unused)
956 {
957 
958 	got_siginfo = 1;
959 }
960