xref: /freebsd/sbin/newfs_msdos/newfs_msdos.c (revision 4436b51dff5736e74da464946049ea6899a88938)
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 #define	MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
55 #define	BPN	  4		/* bits per nibble */
56 #define	NPB	  2		/* nibbles per byte */
57 
58 #define	DOSMAGIC  0xaa55	/* DOS magic number */
59 #define	MINBPS	  512		/* minimum bytes per sector */
60 #define	MAXSPC	  128		/* maximum sectors per cluster */
61 #define	MAXNFT	  16		/* maximum number of FATs */
62 #define	DEFBLK	  4096		/* default block size */
63 #define	DEFBLK16  2048		/* default block size FAT16 */
64 #define	DEFRDE	  512		/* default root directory entries */
65 #define	RESFTE	  2		/* reserved FAT entries */
66 #define	MINCLS12  1U		/* minimum FAT12 clusters */
67 #define	MINCLS16  0xff5U	/* minimum FAT16 clusters */
68 #define	MINCLS32  0xfff5U	/* minimum FAT32 clusters */
69 #define	MAXCLS12  0xff4U	/* maximum FAT12 clusters */
70 #define	MAXCLS16  0xfff4U	/* maximum FAT16 clusters */
71 #define	MAXCLS32  0xffffff4U	/* maximum FAT32 clusters */
72 
73 #define	mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
74 		      (fat) == 16 ? MINCLS16 :	\
75 				    MINCLS32)
76 
77 #define	maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
78 		      (fat) == 16 ? MAXCLS16 :	\
79 				    MAXCLS32)
80 
81 #define	mk1(p, x)				\
82     (p) = (u_int8_t)(x)
83 
84 #define	mk2(p, x)				\
85     (p)[0] = (u_int8_t)(x),			\
86     (p)[1] = (u_int8_t)((x) >> 010)
87 
88 #define	mk4(p, x)				\
89     (p)[0] = (u_int8_t)(x),			\
90     (p)[1] = (u_int8_t)((x) >> 010),		\
91     (p)[2] = (u_int8_t)((x) >> 020),		\
92     (p)[3] = (u_int8_t)((x) >> 030)
93 
94 #define	argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
95 #define	argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
96 #define	argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
97 #define	argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
98 
99 struct bs {
100     u_int8_t bsJump[3];			/* bootstrap entry point */
101     u_int8_t bsOemName[8];		/* OEM name and version */
102 } __packed;
103 
104 struct bsbpb {
105     u_int8_t bpbBytesPerSec[2];		/* bytes per sector */
106     u_int8_t bpbSecPerClust;		/* sectors per cluster */
107     u_int8_t bpbResSectors[2];		/* reserved sectors */
108     u_int8_t bpbFATs;			/* number of FATs */
109     u_int8_t bpbRootDirEnts[2];		/* root directory entries */
110     u_int8_t bpbSectors[2];		/* total sectors */
111     u_int8_t bpbMedia;			/* media descriptor */
112     u_int8_t bpbFATsecs[2];		/* sectors per FAT */
113     u_int8_t bpbSecPerTrack[2];		/* sectors per track */
114     u_int8_t bpbHeads[2];		/* drive heads */
115     u_int8_t bpbHiddenSecs[4];		/* hidden sectors */
116     u_int8_t bpbHugeSectors[4];		/* big total sectors */
117 } __packed;
118 
119 struct bsxbpb {
120     u_int8_t bpbBigFATsecs[4];		/* big sectors per FAT */
121     u_int8_t bpbExtFlags[2];		/* FAT control flags */
122     u_int8_t bpbFSVers[2];		/* file system version */
123     u_int8_t bpbRootClust[4];		/* root directory start cluster */
124     u_int8_t bpbFSInfo[2];		/* file system info sector */
125     u_int8_t bpbBackup[2];		/* backup boot sector */
126     u_int8_t bpbReserved[12];		/* reserved */
127 } __packed;
128 
129 struct bsx {
130     u_int8_t exDriveNumber;		/* drive number */
131     u_int8_t exReserved1;		/* reserved */
132     u_int8_t exBootSignature;		/* extended boot signature */
133     u_int8_t exVolumeID[4];		/* volume ID number */
134     u_int8_t exVolumeLabel[11];		/* volume label */
135     u_int8_t exFileSysType[8];		/* file system type */
136 } __packed;
137 
138 struct de {
139     u_int8_t deName[11];		/* name and extension */
140     u_int8_t deAttributes;		/* attributes */
141     u_int8_t rsvd[10];			/* reserved */
142     u_int8_t deMTime[2];		/* last-modified time */
143     u_int8_t deMDate[2];		/* last-modified date */
144     u_int8_t deStartCluster[2];		/* starting cluster */
145     u_int8_t deFileSize[4];		/* size */
146 } __packed;
147 
148 struct bpb {
149     u_int bpbBytesPerSec;		/* bytes per sector */
150     u_int bpbSecPerClust;		/* sectors per cluster */
151     u_int bpbResSectors;		/* reserved sectors */
152     u_int bpbFATs;			/* number of FATs */
153     u_int bpbRootDirEnts;		/* root directory entries */
154     u_int bpbSectors;			/* total sectors */
155     u_int bpbMedia;			/* media descriptor */
156     u_int bpbFATsecs;			/* sectors per FAT */
157     u_int bpbSecPerTrack;		/* sectors per track */
158     u_int bpbHeads;			/* drive heads */
159     u_int bpbHiddenSecs;		/* hidden sectors */
160     u_int bpbHugeSectors; 		/* big total sectors */
161     u_int bpbBigFATsecs; 		/* big sectors per FAT */
162     u_int bpbRootClust; 		/* root directory start cluster */
163     u_int bpbFSInfo; 			/* file system info sector */
164     u_int bpbBackup; 			/* backup boot sector */
165 };
166 
167 #define	BPBGAP 0, 0, 0, 0, 0, 0
168 
169 static struct {
170     const char *name;
171     struct bpb bpb;
172 } const stdfmt[] = {
173     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
174     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
175     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
176     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
177     {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
178     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
179     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
180     {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
181     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
182     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
183 };
184 
185 static const u_int8_t bootcode[] = {
186     0xfa,			/* cli		    */
187     0x31, 0xc0, 		/* xor	   ax,ax    */
188     0x8e, 0xd0, 		/* mov	   ss,ax    */
189     0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
190     0xfb,			/* sti		    */
191     0x8e, 0xd8, 		/* mov	   ds,ax    */
192     0xe8, 0x00, 0x00,		/* call    $ + 3    */
193     0x5e,			/* pop	   si	    */
194     0x83, 0xc6, 0x19,		/* add	   si,+19h  */
195     0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
196     0xfc,			/* cld		    */
197     0xac,			/* lodsb	    */
198     0x84, 0xc0, 		/* test    al,al    */
199     0x74, 0x06, 		/* jz	   $ + 8    */
200     0xb4, 0x0e, 		/* mov	   ah,0eh   */
201     0xcd, 0x10, 		/* int	   10h	    */
202     0xeb, 0xf5, 		/* jmp	   $ - 9    */
203     0x30, 0xe4, 		/* xor	   ah,ah    */
204     0xcd, 0x16, 		/* int	   16h	    */
205     0xcd, 0x19, 		/* int	   19h	    */
206     0x0d, 0x0a,
207     'N', 'o', 'n', '-', 's', 'y', 's', 't',
208     'e', 'm', ' ', 'd', 'i', 's', 'k',
209     0x0d, 0x0a,
210     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
211     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
212     ' ', 'r', 'e', 'b', 'o', 'o', 't',
213     0x0d, 0x0a,
214     0
215 };
216 
217 static volatile sig_atomic_t got_siginfo;
218 static void infohandler(int);
219 
220 static void check_mounted(const char *, mode_t);
221 static void getstdfmt(const char *, struct bpb *);
222 static void getdiskinfo(int, const char *, const char *, int,
223 			struct bpb *);
224 static void print_bpb(struct bpb *);
225 static u_int ckgeom(const char *, u_int, const char *);
226 static u_int argtou(const char *, u_int, u_int, const char *);
227 static off_t argtooff(const char *, const char *);
228 static int oklabel(const char *);
229 static void mklabel(u_int8_t *, const char *);
230 static void setstr(u_int8_t *, const char *, size_t);
231 static void usage(void);
232 
233 /*
234  * Construct a FAT12, FAT16, or FAT32 file system.
235  */
236 int
237 main(int argc, char *argv[])
238 {
239     static const char opts[] = "@:NB:C:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
240     const char *opt_B = NULL, *opt_L = NULL, *opt_O = NULL, *opt_f = NULL;
241     u_int opt_F = 0, opt_I = 0, opt_S = 0, opt_a = 0, opt_b = 0, opt_c = 0;
242     u_int opt_e = 0, opt_h = 0, opt_i = 0, opt_k = 0, opt_m = 0, opt_n = 0;
243     u_int opt_o = 0, opt_r = 0, opt_s = 0, opt_u = 0;
244     int opt_N = 0;
245     int Iflag = 0, mflag = 0, oflag = 0;
246     char buf[MAXPATHLEN];
247     struct sigaction si_sa;
248     struct stat sb;
249     struct timeval tv;
250     struct bpb bpb;
251     struct tm *tm;
252     struct bs *bs;
253     struct bsbpb *bsbpb;
254     struct bsxbpb *bsxbpb;
255     struct bsx *bsx;
256     struct de *de;
257     u_int8_t *img;
258     const char *fname, *dtype, *bname;
259     ssize_t n;
260     time_t now;
261     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
262     int ch, fd, fd1;
263     off_t opt_create = 0, opt_ofs = 0;
264 
265     while ((ch = getopt(argc, argv, opts)) != -1)
266 	switch (ch) {
267 	case '@':
268 	    opt_ofs = argtooff(optarg, "offset");
269 	    break;
270 	case 'N':
271 	    opt_N = 1;
272 	    break;
273 	case 'B':
274 	    opt_B = optarg;
275 	    break;
276 	case 'C':
277 	    opt_create = argtooff(optarg, "create size");
278 	    break;
279 	case 'F':
280 	    if (strcmp(optarg, "12") &&
281 		strcmp(optarg, "16") &&
282 		strcmp(optarg, "32"))
283 		errx(1, "%s: bad FAT type", optarg);
284 	    opt_F = atoi(optarg);
285 	    break;
286 	case 'I':
287 	    opt_I = argto4(optarg, 0, "volume ID");
288 	    Iflag = 1;
289 	    break;
290 	case 'L':
291 	    if (!oklabel(optarg))
292 		errx(1, "%s: bad volume label", optarg);
293 	    opt_L = optarg;
294 	    break;
295 	case 'O':
296 	    if (strlen(optarg) > 8)
297 		errx(1, "%s: bad OEM string", optarg);
298 	    opt_O = optarg;
299 	    break;
300 	case 'S':
301 	    opt_S = argto2(optarg, 1, "bytes/sector");
302 	    break;
303 	case 'a':
304 	    opt_a = argto4(optarg, 1, "sectors/FAT");
305 	    break;
306 	case 'b':
307 	    opt_b = argtox(optarg, 1, "block size");
308 	    opt_c = 0;
309 	    break;
310 	case 'c':
311 	    opt_c = argto1(optarg, 1, "sectors/cluster");
312 	    opt_b = 0;
313 	    break;
314 	case 'e':
315 	    opt_e = argto2(optarg, 1, "directory entries");
316 	    break;
317 	case 'f':
318 	    opt_f = optarg;
319 	    break;
320 	case 'h':
321 	    opt_h = argto2(optarg, 1, "drive heads");
322 	    break;
323 	case 'i':
324 	    opt_i = argto2(optarg, 1, "info sector");
325 	    break;
326 	case 'k':
327 	    opt_k = argto2(optarg, 1, "backup sector");
328 	    break;
329 	case 'm':
330 	    opt_m = argto1(optarg, 0, "media descriptor");
331 	    mflag = 1;
332 	    break;
333 	case 'n':
334 	    opt_n = argto1(optarg, 1, "number of FATs");
335 	    break;
336 	case 'o':
337 	    opt_o = argto4(optarg, 0, "hidden sectors");
338 	    oflag = 1;
339 	    break;
340 	case 'r':
341 	    opt_r = argto2(optarg, 1, "reserved sectors");
342 	    break;
343 	case 's':
344 	    opt_s = argto4(optarg, 1, "file system size");
345 	    break;
346 	case 'u':
347 	    opt_u = argto2(optarg, 1, "sectors/track");
348 	    break;
349 	default:
350 	    usage();
351 	}
352     argc -= optind;
353     argv += optind;
354     if (argc < 1 || argc > 2)
355 	usage();
356     fname = *argv++;
357     if (!opt_create && !strchr(fname, '/')) {
358 	snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
359 	if (!(fname = strdup(buf)))
360 	    err(1, NULL);
361     }
362     dtype = *argv;
363     if (opt_create) {
364 	if (opt_N)
365 	    errx(1, "create (-C) is incompatible with -N");
366 	fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
367 	if (fd == -1)
368 	    errx(1, "failed to create %s", fname);
369 	if (ftruncate(fd, opt_create))
370 	    errx(1, "failed to initialize %jd bytes", (intmax_t)opt_create);
371     } else if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1)
372 	err(1, "%s", fname);
373     if (fstat(fd, &sb))
374 	err(1, "%s", fname);
375     if (opt_create) {
376 	if (!S_ISREG(sb.st_mode))
377 	    warnx("warning, %s is not a regular file", fname);
378     } else {
379 	if (!S_ISCHR(sb.st_mode))
380 	    warnx("warning, %s is not a character device", fname);
381     }
382     if (!opt_N)
383 	check_mounted(fname, sb.st_mode);
384     if (opt_ofs && opt_ofs != lseek(fd, opt_ofs, SEEK_SET))
385 	errx(1, "cannot seek to %jd", (intmax_t)opt_ofs);
386     memset(&bpb, 0, sizeof(bpb));
387     if (opt_f) {
388 	getstdfmt(opt_f, &bpb);
389 	bpb.bpbHugeSectors = bpb.bpbSectors;
390 	bpb.bpbSectors = 0;
391 	bpb.bpbBigFATsecs = bpb.bpbFATsecs;
392 	bpb.bpbFATsecs = 0;
393     }
394     if (opt_h)
395 	bpb.bpbHeads = opt_h;
396     if (opt_u)
397 	bpb.bpbSecPerTrack = opt_u;
398     if (opt_S)
399 	bpb.bpbBytesPerSec = opt_S;
400     if (opt_s)
401 	bpb.bpbHugeSectors = opt_s;
402     if (oflag)
403 	bpb.bpbHiddenSecs = opt_o;
404     if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag))) {
405 	off_t delta;
406 	getdiskinfo(fd, fname, dtype, oflag, &bpb);
407 	bpb.bpbHugeSectors -= (opt_ofs / bpb.bpbBytesPerSec);
408 	delta = bpb.bpbHugeSectors % bpb.bpbSecPerTrack;
409 	if (delta != 0) {
410 	    warnx("trim %d sectors to adjust to a multiple of %d",
411 		(int)delta, bpb.bpbSecPerTrack);
412 	    bpb.bpbHugeSectors -= delta;
413 	}
414 	if (bpb.bpbSecPerClust == 0) {	/* set defaults */
415 	    if (bpb.bpbHugeSectors <= 6000)	/* about 3MB -> 512 bytes */
416 		bpb.bpbSecPerClust = 1;
417 	    else if (bpb.bpbHugeSectors <= (1<<17)) /* 64M -> 4k */
418 		bpb.bpbSecPerClust = 8;
419 	    else if (bpb.bpbHugeSectors <= (1<<19)) /* 256M -> 8k */
420 		bpb.bpbSecPerClust = 16;
421 	    else if (bpb.bpbHugeSectors <= (1<<21)) /* 1G -> 16k */
422 		bpb.bpbSecPerClust = 32;
423 	    else
424 		bpb.bpbSecPerClust = 64;		/* otherwise 32k */
425 	}
426     }
427     if (!powerof2(bpb.bpbBytesPerSec))
428 	errx(1, "bytes/sector (%u) is not a power of 2", bpb.bpbBytesPerSec);
429     if (bpb.bpbBytesPerSec < MINBPS)
430 	errx(1, "bytes/sector (%u) is too small; minimum is %u",
431 	     bpb.bpbBytesPerSec, MINBPS);
432     if (!(fat = opt_F)) {
433 	if (opt_f)
434 	    fat = 12;
435 	else if (!opt_e && (opt_i || opt_k))
436 	    fat = 32;
437     }
438     if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
439 	errx(1, "-%c is not a legal FAT%s option",
440 	     fat == 32 ? 'e' : opt_i ? 'i' : 'k',
441 	     fat == 32 ? "32" : "12/16");
442     if (opt_f && fat == 32)
443 	bpb.bpbRootDirEnts = 0;
444     if (opt_b) {
445 	if (!powerof2(opt_b))
446 	    errx(1, "block size (%u) is not a power of 2", opt_b);
447 	if (opt_b < bpb.bpbBytesPerSec)
448 	    errx(1, "block size (%u) is too small; minimum is %u",
449 		 opt_b, bpb.bpbBytesPerSec);
450 	if (opt_b > bpb.bpbBytesPerSec * MAXSPC)
451 	    errx(1, "block size (%u) is too large; maximum is %u",
452 		 opt_b, bpb.bpbBytesPerSec * MAXSPC);
453 	bpb.bpbSecPerClust = opt_b / bpb.bpbBytesPerSec;
454     }
455     if (opt_c) {
456 	if (!powerof2(opt_c))
457 	    errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
458 	bpb.bpbSecPerClust = opt_c;
459     }
460     if (opt_r)
461 	bpb.bpbResSectors = opt_r;
462     if (opt_n) {
463 	if (opt_n > MAXNFT)
464 	    errx(1, "number of FATs (%u) is too large; maximum is %u",
465 		 opt_n, MAXNFT);
466 	bpb.bpbFATs = opt_n;
467     }
468     if (opt_e)
469 	bpb.bpbRootDirEnts = opt_e;
470     if (mflag) {
471 	if (opt_m < 0xf0)
472 	    errx(1, "illegal media descriptor (%#x)", opt_m);
473 	bpb.bpbMedia = opt_m;
474     }
475     if (opt_a)
476 	bpb.bpbBigFATsecs = opt_a;
477     if (opt_i)
478 	bpb.bpbFSInfo = opt_i;
479     if (opt_k)
480 	bpb.bpbBackup = opt_k;
481     bss = 1;
482     bname = NULL;
483     fd1 = -1;
484     if (opt_B) {
485 	bname = opt_B;
486 	if (!strchr(bname, '/')) {
487 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
488 	    if (!(bname = strdup(buf)))
489 		err(1, NULL);
490 	}
491 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
492 	    err(1, "%s", bname);
493 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bpbBytesPerSec ||
494 	    sb.st_size < bpb.bpbBytesPerSec ||
495 	    sb.st_size > bpb.bpbBytesPerSec * MAXU16)
496 	    errx(1, "%s: inappropriate file type or format", bname);
497 	bss = sb.st_size / bpb.bpbBytesPerSec;
498     }
499     if (!bpb.bpbFATs)
500 	bpb.bpbFATs = 2;
501     if (!fat) {
502 	if (bpb.bpbHugeSectors < (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
503 	    howmany((RESFTE + (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1)) *
504 		(bpb.bpbSecPerClust ? 16 : 12) / BPN,
505 		bpb.bpbBytesPerSec * NPB) *
506 	    bpb.bpbFATs +
507 	    howmany(bpb.bpbRootDirEnts ? bpb.bpbRootDirEnts : DEFRDE,
508 		    bpb.bpbBytesPerSec / sizeof(struct de)) +
509 	    (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1) *
510 	    (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
511 	     howmany(DEFBLK, bpb.bpbBytesPerSec)))
512 	    fat = 12;
513 	else if (bpb.bpbRootDirEnts || bpb.bpbHugeSectors <
514 		 (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
515 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bpbBytesPerSec) *
516 		 bpb.bpbFATs +
517 		 howmany(DEFRDE, bpb.bpbBytesPerSec / sizeof(struct de)) +
518 		 (MAXCLS16 + 1) *
519 		 (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
520 		  howmany(8192, bpb.bpbBytesPerSec)))
521 	    fat = 16;
522 	else
523 	    fat = 32;
524     }
525     x = bss;
526     if (fat == 32) {
527 	if (!bpb.bpbFSInfo) {
528 	    if (x == MAXU16 || x == bpb.bpbBackup)
529 		errx(1, "no room for info sector");
530 	    bpb.bpbFSInfo = x;
531 	}
532 	if (bpb.bpbFSInfo != MAXU16 && x <= bpb.bpbFSInfo)
533 	    x = bpb.bpbFSInfo + 1;
534 	if (!bpb.bpbBackup) {
535 	    if (x == MAXU16)
536 		errx(1, "no room for backup sector");
537 	    bpb.bpbBackup = x;
538 	} else if (bpb.bpbBackup != MAXU16 && bpb.bpbBackup == bpb.bpbFSInfo)
539 	    errx(1, "backup sector would overwrite info sector");
540 	if (bpb.bpbBackup != MAXU16 && x <= bpb.bpbBackup)
541 	    x = bpb.bpbBackup + 1;
542     }
543     if (!bpb.bpbResSectors)
544 	bpb.bpbResSectors = fat == 32 ?
545 	    MAX(x, MAX(16384 / bpb.bpbBytesPerSec, 4)) : x;
546     else if (bpb.bpbResSectors < x)
547 	errx(1, "too few reserved sectors (need %d have %d)", x,
548 	     bpb.bpbResSectors);
549     if (fat != 32 && !bpb.bpbRootDirEnts)
550 	bpb.bpbRootDirEnts = DEFRDE;
551     rds = howmany(bpb.bpbRootDirEnts, bpb.bpbBytesPerSec / sizeof(struct de));
552     if (!bpb.bpbSecPerClust)
553 	for (bpb.bpbSecPerClust = howmany(fat == 16 ? DEFBLK16 :
554 					  DEFBLK, bpb.bpbBytesPerSec);
555 	     bpb.bpbSecPerClust < MAXSPC &&
556 	     bpb.bpbResSectors +
557 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
558 		     bpb.bpbBytesPerSec * NPB) *
559 	     bpb.bpbFATs +
560 	     rds +
561 	     (u_int64_t) (maxcls(fat) + 1) *
562 	     bpb.bpbSecPerClust <= bpb.bpbHugeSectors;
563 	     bpb.bpbSecPerClust <<= 1)
564 	    continue;
565     if (fat != 32 && bpb.bpbBigFATsecs > MAXU16)
566 	errx(1, "too many sectors/FAT for FAT12/16");
567     x1 = bpb.bpbResSectors + rds;
568     x = bpb.bpbBigFATsecs ? bpb.bpbBigFATsecs : 1;
569     if (x1 + (u_int64_t)x * bpb.bpbFATs > bpb.bpbHugeSectors)
570 	errx(1, "meta data exceeds file system size");
571     x1 += x * bpb.bpbFATs;
572     x = (u_int64_t)(bpb.bpbHugeSectors - x1) * bpb.bpbBytesPerSec * NPB /
573 	(bpb.bpbSecPerClust * bpb.bpbBytesPerSec * NPB + fat /
574 	 BPN * bpb.bpbFATs);
575     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
576 		 bpb.bpbBytesPerSec * NPB);
577     if (!bpb.bpbBigFATsecs) {
578 	bpb.bpbBigFATsecs = x2;
579 	x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
580     }
581     cls = (bpb.bpbHugeSectors - x1) / bpb.bpbSecPerClust;
582     x = (u_int64_t)bpb.bpbBigFATsecs * bpb.bpbBytesPerSec * NPB / (fat / BPN) -
583 	RESFTE;
584     if (cls > x)
585 	cls = x;
586     if (bpb.bpbBigFATsecs < x2)
587 	warnx("warning: sectors/FAT limits file system to %u clusters",
588 	      cls);
589     if (cls < mincls(fat))
590 	errx(1, "%u clusters too few clusters for FAT%u, need %u", cls, fat,
591 	    mincls(fat));
592     if (cls > maxcls(fat)) {
593 	cls = maxcls(fat);
594 	bpb.bpbHugeSectors = x1 + (cls + 1) * bpb.bpbSecPerClust - 1;
595 	warnx("warning: FAT type limits file system to %u sectors",
596 	      bpb.bpbHugeSectors);
597     }
598     printf("%s: %u sector%s in %u FAT%u cluster%s "
599 	   "(%u bytes/cluster)\n", fname, cls * bpb.bpbSecPerClust,
600 	   cls * bpb.bpbSecPerClust == 1 ? "" : "s", cls, fat,
601 	   cls == 1 ? "" : "s", bpb.bpbBytesPerSec * bpb.bpbSecPerClust);
602     if (!bpb.bpbMedia)
603 	bpb.bpbMedia = !bpb.bpbHiddenSecs ? 0xf0 : 0xf8;
604     if (fat == 32)
605 	bpb.bpbRootClust = RESFTE;
606     if (bpb.bpbHiddenSecs + bpb.bpbHugeSectors <= MAXU16) {
607 	bpb.bpbSectors = bpb.bpbHugeSectors;
608 	bpb.bpbHugeSectors = 0;
609     }
610     if (fat != 32) {
611 	bpb.bpbFATsecs = bpb.bpbBigFATsecs;
612 	bpb.bpbBigFATsecs = 0;
613     }
614     print_bpb(&bpb);
615     if (!opt_N) {
616 	gettimeofday(&tv, NULL);
617 	now = tv.tv_sec;
618 	tm = localtime(&now);
619 	if (!(img = malloc(bpb.bpbBytesPerSec)))
620 	    err(1, NULL);
621 	dir = bpb.bpbResSectors + (bpb.bpbFATsecs ? bpb.bpbFATsecs :
622 				   bpb.bpbBigFATsecs) * bpb.bpbFATs;
623 	memset(&si_sa, 0, sizeof(si_sa));
624 	si_sa.sa_handler = infohandler;
625 	if (sigaction(SIGINFO, &si_sa, NULL) == -1)
626 		err(1, "sigaction SIGINFO");
627 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.bpbSecPerClust : rds); lsn++) {
628 	    if (got_siginfo) {
629 		    fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
630 			fname, lsn,
631 			(dir + (fat == 32 ? bpb.bpbSecPerClust: rds)),
632 			(lsn * 100) / (dir +
633 			    (fat == 32 ? bpb.bpbSecPerClust: rds)));
634 		    got_siginfo = 0;
635 	    }
636 	    x = lsn;
637 	    if (opt_B &&
638 		fat == 32 && bpb.bpbBackup != MAXU16 &&
639 		bss <= bpb.bpbBackup && x >= bpb.bpbBackup) {
640 		x -= bpb.bpbBackup;
641 		if (!x && lseek(fd1, opt_ofs, SEEK_SET))
642 		    err(1, "%s", bname);
643 	    }
644 	    if (opt_B && x < bss) {
645 		if ((n = read(fd1, img, bpb.bpbBytesPerSec)) == -1)
646 		    err(1, "%s", bname);
647 		if ((unsigned)n != bpb.bpbBytesPerSec)
648 		    errx(1, "%s: can't read sector %u", bname, x);
649 	    } else
650 		memset(img, 0, bpb.bpbBytesPerSec);
651 	    if (!lsn ||
652 		(fat == 32 && bpb.bpbBackup != MAXU16 &&
653 		 lsn == bpb.bpbBackup)) {
654 		x1 = sizeof(struct bs);
655 		bsbpb = (struct bsbpb *)(img + x1);
656 		mk2(bsbpb->bpbBytesPerSec, bpb.bpbBytesPerSec);
657 		mk1(bsbpb->bpbSecPerClust, bpb.bpbSecPerClust);
658 		mk2(bsbpb->bpbResSectors, bpb.bpbResSectors);
659 		mk1(bsbpb->bpbFATs, bpb.bpbFATs);
660 		mk2(bsbpb->bpbRootDirEnts, bpb.bpbRootDirEnts);
661 		mk2(bsbpb->bpbSectors, bpb.bpbSectors);
662 		mk1(bsbpb->bpbMedia, bpb.bpbMedia);
663 		mk2(bsbpb->bpbFATsecs, bpb.bpbFATsecs);
664 		mk2(bsbpb->bpbSecPerTrack, bpb.bpbSecPerTrack);
665 		mk2(bsbpb->bpbHeads, bpb.bpbHeads);
666 		mk4(bsbpb->bpbHiddenSecs, bpb.bpbHiddenSecs);
667 		mk4(bsbpb->bpbHugeSectors, bpb.bpbHugeSectors);
668 		x1 += sizeof(struct bsbpb);
669 		if (fat == 32) {
670 		    bsxbpb = (struct bsxbpb *)(img + x1);
671 		    mk4(bsxbpb->bpbBigFATsecs, bpb.bpbBigFATsecs);
672 		    mk2(bsxbpb->bpbExtFlags, 0);
673 		    mk2(bsxbpb->bpbFSVers, 0);
674 		    mk4(bsxbpb->bpbRootClust, bpb.bpbRootClust);
675 		    mk2(bsxbpb->bpbFSInfo, bpb.bpbFSInfo);
676 		    mk2(bsxbpb->bpbBackup, bpb.bpbBackup);
677 		    x1 += sizeof(struct bsxbpb);
678 		}
679 		bsx = (struct bsx *)(img + x1);
680 		mk1(bsx->exBootSignature, 0x29);
681 		if (Iflag)
682 		    x = opt_I;
683 		else
684 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
685 			  (u_int)tm->tm_mday) +
686 			 ((u_int)tm->tm_sec << 8 |
687 			  (u_int)(tv.tv_usec / 10))) << 16 |
688 			((u_int)(1900 + tm->tm_year) +
689 			 ((u_int)tm->tm_hour << 8 |
690 			  (u_int)tm->tm_min));
691 		mk4(bsx->exVolumeID, x);
692 		mklabel(bsx->exVolumeLabel, opt_L ? opt_L : "NO NAME");
693 		sprintf(buf, "FAT%u", fat);
694 		setstr(bsx->exFileSysType, buf, sizeof(bsx->exFileSysType));
695 		if (!opt_B) {
696 		    x1 += sizeof(struct bsx);
697 		    bs = (struct bs *)img;
698 		    mk1(bs->bsJump[0], 0xeb);
699 		    mk1(bs->bsJump[1], x1 - 2);
700 		    mk1(bs->bsJump[2], 0x90);
701 		    setstr(bs->bsOemName, opt_O ? opt_O : "BSD4.4  ",
702 			   sizeof(bs->bsOemName));
703 		    memcpy(img + x1, bootcode, sizeof(bootcode));
704 		    mk2(img + MINBPS - 2, DOSMAGIC);
705 		}
706 	    } else if (fat == 32 && bpb.bpbFSInfo != MAXU16 &&
707 		       (lsn == bpb.bpbFSInfo ||
708 			(bpb.bpbBackup != MAXU16 &&
709 			 lsn == bpb.bpbBackup + bpb.bpbFSInfo))) {
710 		mk4(img, 0x41615252);
711 		mk4(img + MINBPS - 28, 0x61417272);
712 		mk4(img + MINBPS - 24, 0xffffffff);
713 		mk4(img + MINBPS - 20, bpb.bpbRootClust);
714 		mk2(img + MINBPS - 2, DOSMAGIC);
715 	    } else if (lsn >= bpb.bpbResSectors && lsn < dir &&
716 		       !((lsn - bpb.bpbResSectors) %
717 			 (bpb.bpbFATsecs ? bpb.bpbFATsecs :
718 			  bpb.bpbBigFATsecs))) {
719 		mk1(img[0], bpb.bpbMedia);
720 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
721 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
722 	    } else if (lsn == dir && opt_L) {
723 		de = (struct de *)img;
724 		mklabel(de->deName, opt_L);
725 		mk1(de->deAttributes, 050);
726 		x = (u_int)tm->tm_hour << 11 |
727 		    (u_int)tm->tm_min << 5 |
728 		    (u_int)tm->tm_sec >> 1;
729 		mk2(de->deMTime, x);
730 		x = (u_int)(tm->tm_year - 80) << 9 |
731 		    (u_int)(tm->tm_mon + 1) << 5 |
732 		    (u_int)tm->tm_mday;
733 		mk2(de->deMDate, x);
734 	    }
735 	    if ((n = write(fd, img, bpb.bpbBytesPerSec)) == -1)
736 		err(1, "%s", fname);
737 	    if ((unsigned)n != bpb.bpbBytesPerSec)
738 		errx(1, "%s: can't write sector %u", fname, lsn);
739 	}
740     }
741     return 0;
742 }
743 
744 /*
745  * Exit with error if file system is mounted.
746  */
747 static void
748 check_mounted(const char *fname, mode_t mode)
749 {
750     struct statfs *mp;
751     const char *s1, *s2;
752     size_t len;
753     int n, r;
754 
755     if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
756 	err(1, "getmntinfo");
757     len = strlen(_PATH_DEV);
758     s1 = fname;
759     if (!strncmp(s1, _PATH_DEV, len))
760 	s1 += len;
761     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
762     for (; n--; mp++) {
763 	s2 = mp->f_mntfromname;
764 	if (!strncmp(s2, _PATH_DEV, len))
765 	    s2 += len;
766 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
767 	    !strcmp(s1, s2))
768 	    errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
769     }
770 }
771 
772 /*
773  * Get a standard format.
774  */
775 static void
776 getstdfmt(const char *fmt, struct bpb *bpb)
777 {
778     u_int x, i;
779 
780     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
781     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
782     if (i == x)
783 	errx(1, "%s: unknown standard format", fmt);
784     *bpb = stdfmt[i].bpb;
785 }
786 
787 /*
788  * Get disk slice, partition, and geometry information.
789  */
790 static void
791 getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
792 	    struct bpb *bpb)
793 {
794     struct disklabel *lp, dlp;
795     struct fd_type type;
796     off_t ms, hs = 0;
797 
798     lp = NULL;
799 
800     /* If the user specified a disk type, try to use that */
801     if (dtype != NULL) {
802 	lp = getdiskbyname(dtype);
803     }
804 
805     /* Maybe it's a floppy drive */
806     if (lp == NULL) {
807 	if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
808 	    struct stat st;
809 
810 	    if (fstat(fd, &st))
811 		err(1, "cannot get disk size");
812 	    /* create a fake geometry for a file image */
813 	    ms = st.st_size;
814 	    dlp.d_secsize = 512;
815 	    dlp.d_nsectors = 63;
816 	    dlp.d_ntracks = 255;
817 	    dlp.d_secperunit = ms / dlp.d_secsize;
818 	    lp = &dlp;
819 	} else if (ioctl(fd, FD_GTYPE, &type) != -1) {
820 	    dlp.d_secsize = 128 << type.secsize;
821 	    dlp.d_nsectors = type.sectrac;
822 	    dlp.d_ntracks = type.heads;
823 	    dlp.d_secperunit = ms / dlp.d_secsize;
824 	    lp = &dlp;
825 	}
826     }
827 
828     /* Maybe it's a fixed drive */
829     if (lp == NULL) {
830 	if (bpb->bpbBytesPerSec)
831 	    dlp.d_secsize = bpb->bpbBytesPerSec;
832 	if (bpb->bpbBytesPerSec == 0 && ioctl(fd, DIOCGSECTORSIZE,
833 					      &dlp.d_secsize) == -1)
834 	    err(1, "cannot get sector size");
835 
836 	dlp.d_secperunit = ms / dlp.d_secsize;
837 
838 	if (bpb->bpbSecPerTrack == 0 && ioctl(fd, DIOCGFWSECTORS,
839 					      &dlp.d_nsectors) == -1) {
840 	    warn("cannot get number of sectors per track");
841 	    dlp.d_nsectors = 63;
842 	}
843 	if (bpb->bpbHeads == 0 &&
844 	    ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
845 	    warn("cannot get number of heads");
846 	    if (dlp.d_secperunit <= 63*1*1024)
847 		dlp.d_ntracks = 1;
848 	    else if (dlp.d_secperunit <= 63*16*1024)
849 		dlp.d_ntracks = 16;
850 	    else
851 		dlp.d_ntracks = 255;
852 	}
853 
854 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
855 	lp = &dlp;
856     }
857 
858     if (bpb->bpbBytesPerSec == 0)
859 	bpb->bpbBytesPerSec = ckgeom(fname, lp->d_secsize, "bytes/sector");
860     if (bpb->bpbSecPerTrack == 0)
861 	bpb->bpbSecPerTrack = ckgeom(fname, lp->d_nsectors, "sectors/track");
862     if (bpb->bpbHeads == 0)
863 	bpb->bpbHeads = ckgeom(fname, lp->d_ntracks, "drive heads");
864     if (bpb->bpbHugeSectors == 0)
865 	bpb->bpbHugeSectors = lp->d_secperunit;
866     if (bpb->bpbHiddenSecs == 0)
867 	bpb->bpbHiddenSecs = hs;
868 }
869 
870 /*
871  * Print out BPB values.
872  */
873 static void
874 print_bpb(struct bpb *bpb)
875 {
876     printf("BytesPerSec=%u SecPerClust=%u ResSectors=%u FATs=%u",
877 	   bpb->bpbBytesPerSec, bpb->bpbSecPerClust, bpb->bpbResSectors,
878 	   bpb->bpbFATs);
879     if (bpb->bpbRootDirEnts)
880 	printf(" RootDirEnts=%u", bpb->bpbRootDirEnts);
881     if (bpb->bpbSectors)
882 	printf(" Sectors=%u", bpb->bpbSectors);
883     printf(" Media=%#x", bpb->bpbMedia);
884     if (bpb->bpbFATsecs)
885 	printf(" FATsecs=%u", bpb->bpbFATsecs);
886     printf(" SecPerTrack=%u Heads=%u HiddenSecs=%u", bpb->bpbSecPerTrack,
887 	   bpb->bpbHeads, bpb->bpbHiddenSecs);
888     if (bpb->bpbHugeSectors)
889 	printf(" HugeSectors=%u", bpb->bpbHugeSectors);
890     if (!bpb->bpbFATsecs) {
891 	printf(" FATsecs=%u RootCluster=%u", bpb->bpbBigFATsecs,
892 	       bpb->bpbRootClust);
893 	printf(" FSInfo=");
894 	printf(bpb->bpbFSInfo == MAXU16 ? "%#x" : "%u", bpb->bpbFSInfo);
895 	printf(" Backup=");
896 	printf(bpb->bpbBackup == MAXU16 ? "%#x" : "%u", bpb->bpbBackup);
897     }
898     printf("\n");
899 }
900 
901 /*
902  * Check a disk geometry value.
903  */
904 static u_int
905 ckgeom(const char *fname, u_int val, const char *msg)
906 {
907     if (!val)
908 	errx(1, "%s: no default %s", fname, msg);
909     if (val > MAXU16)
910 	errx(1, "%s: illegal %s %d", fname, msg, val);
911     return val;
912 }
913 
914 /*
915  * Convert and check a numeric option argument.
916  */
917 static u_int
918 argtou(const char *arg, u_int lo, u_int hi, const char *msg)
919 {
920     char *s;
921     u_long x;
922 
923     errno = 0;
924     x = strtoul(arg, &s, 0);
925     if (errno || !*arg || *s || x < lo || x > hi)
926 	errx(1, "%s: bad %s", arg, msg);
927     return x;
928 }
929 
930 /*
931  * Same for off_t, with optional skmgpP suffix
932  */
933 static off_t
934 argtooff(const char *arg, const char *msg)
935 {
936     char *s;
937     off_t x;
938 
939     errno = 0;
940     x = strtoll(arg, &s, 0);
941     /* allow at most one extra char */
942     if (errno || x < 0 || (s[0] && s[1]) )
943 	errx(1, "%s: bad %s", arg, msg);
944     if (*s) {	/* the extra char is the multiplier */
945 	switch (*s) {
946 	default:
947 	    errx(1, "%s: bad %s", arg, msg);
948 	    /* notreached */
949 
950 	case 's':		/* sector */
951 	case 'S':
952 	    x <<= 9;		/* times 512 */
953 	    break;
954 
955 	case 'k':		/* kilobyte */
956 	case 'K':
957 	    x <<= 10;		/* times 1024 */
958 	    break;
959 
960 	case 'm':		/* megabyte */
961 	case 'M':
962 	    x <<= 20;		/* times 1024*1024 */
963 	    break;
964 
965 	case 'g':		/* gigabyte */
966 	case 'G':
967 	    x <<= 30;		/* times 1024*1024*1024 */
968 	    break;
969 
970 	case 'p':		/* partition start */
971 	case 'P':
972 	case 'l':		/* partition length */
973 	case 'L':
974 	    errx(1, "%s: not supported yet %s", arg, msg);
975 	    /* notreached */
976 	}
977     }
978     return x;
979 }
980 
981 /*
982  * Check a volume label.
983  */
984 static int
985 oklabel(const char *src)
986 {
987     int c, i;
988 
989     for (i = 0; i <= 11; i++) {
990 	c = (u_char)*src++;
991 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
992 	    break;
993     }
994     return i && !c;
995 }
996 
997 /*
998  * Make a volume label.
999  */
1000 static void
1001 mklabel(u_int8_t *dest, const char *src)
1002 {
1003     int c, i;
1004 
1005     for (i = 0; i < 11; i++) {
1006 	c = *src ? toupper(*src++) : ' ';
1007 	*dest++ = !i && c == '\xe5' ? 5 : c;
1008     }
1009 }
1010 
1011 /*
1012  * Copy string, padding with spaces.
1013  */
1014 static void
1015 setstr(u_int8_t *dest, const char *src, size_t len)
1016 {
1017     while (len--)
1018 	*dest++ = *src ? *src++ : ' ';
1019 }
1020 
1021 /*
1022  * Print usage message.
1023  */
1024 static void
1025 usage(void)
1026 {
1027 	fprintf(stderr,
1028 	    "usage: newfs_msdos [ -options ] special [disktype]\n"
1029 	    "where the options are:\n"
1030 	    "\t-@ create file system at specified offset\n"
1031 	    "\t-B get bootstrap from file\n"
1032 	    "\t-C create image file with specified size\n"
1033 	    "\t-F FAT type (12, 16, or 32)\n"
1034 	    "\t-I volume ID\n"
1035 	    "\t-L volume label\n"
1036 	    "\t-N don't create file system: just print out parameters\n"
1037 	    "\t-O OEM string\n"
1038 	    "\t-S bytes/sector\n"
1039 	    "\t-a sectors/FAT\n"
1040 	    "\t-b block size\n"
1041 	    "\t-c sectors/cluster\n"
1042 	    "\t-e root directory entries\n"
1043 	    "\t-f standard format\n"
1044 	    "\t-h drive heads\n"
1045 	    "\t-i file system info sector\n"
1046 	    "\t-k backup boot sector\n"
1047 	    "\t-m media descriptor\n"
1048 	    "\t-n number of FATs\n"
1049 	    "\t-o hidden sectors\n"
1050 	    "\t-r reserved sectors\n"
1051 	    "\t-s file system size (sectors)\n"
1052 	    "\t-u sectors/track\n");
1053 	exit(1);
1054 }
1055 
1056 static void
1057 infohandler(int sig __unused)
1058 {
1059 
1060 	got_siginfo = 1;
1061 }
1062