xref: /openbsd-src/usr.sbin/makefs/msdos/mkfs_msdos.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /*	$OpenBSD: mkfs_msdos.c,v 1.5 2017/11/02 11:06:54 jca Exp $	*/
2 /*	$NetBSD: mkfs_msdos.c,v 1.10 2016/04/03 11:00:13 mlelstv Exp $	*/
3 
4 /*
5  * Copyright (c) 1998 Robert Nordier
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
24  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
26  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
28  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/time.h>
34 
35 #include <ctype.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <paths.h>
40 #include <stdio.h>
41 #include <stdint.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <time.h>
45 #include <unistd.h>
46 #include <signal.h>
47 
48 #include <util.h>
49 #include <disktab.h>
50 
51 #include "makefs.h"
52 #include "msdos/mkfs_msdos.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  1		/* minimum FAT12 clusters */
67 #define MINCLS16  0xff5		/* minimum FAT16 clusters */
68 #define MINCLS32  0xfff5	/* minimum FAT32 clusters */
69 #define MAXCLS12  0xff4		/* maximum FAT12 clusters */
70 #define MAXCLS16  0xfff4	/* maximum FAT16 clusters */
71 #define MAXCLS32  0xffffff4	/* maximum FAT32 clusters */
72 
73 #define mincls(fat_type)  ((fat_type) == 12 ? MINCLS12 :	\
74 		      (fat_type) == 16 ? MINCLS16 :	\
75 				    MINCLS32)
76 
77 #define maxcls(fat_type)  ((fat_type) == 12 ? MAXCLS12 :	\
78 		      (fat_type) == 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 struct bs {
95     u_int8_t jmp[3];		/* bootstrap entry point */
96     u_int8_t oem[8];		/* OEM name and version */
97 };
98 
99 struct bsbpb {
100     u_int8_t bps[2];		/* bytes per sector */
101     u_int8_t spc;		/* sectors per cluster */
102     u_int8_t res[2];		/* reserved sectors */
103     u_int8_t nft;		/* number of FATs */
104     u_int8_t rde[2];		/* root directory entries */
105     u_int8_t sec[2];		/* total sectors */
106     u_int8_t mid;		/* media descriptor */
107     u_int8_t spf[2];		/* sectors per FAT */
108     u_int8_t spt[2];		/* sectors per track */
109     u_int8_t hds[2];		/* drive heads */
110     u_int8_t hid[4];		/* hidden sectors */
111     u_int8_t bsec[4];		/* big total sectors */
112 };
113 
114 struct bsxbpb {
115     u_int8_t bspf[4];		/* big sectors per FAT */
116     u_int8_t xflg[2];		/* FAT control flags */
117     u_int8_t vers[2];		/* file system version */
118     u_int8_t rdcl[4];		/* root directory start cluster */
119     u_int8_t infs[2];		/* file system info sector */
120     u_int8_t bkbs[2];		/* backup boot sector */
121     u_int8_t rsvd[12];		/* reserved */
122 };
123 
124 struct bsx {
125     u_int8_t drv;		/* drive number */
126     u_int8_t rsvd;		/* reserved */
127     u_int8_t sig;		/* extended boot signature */
128     u_int8_t volid[4];		/* volume ID number */
129     u_int8_t label[11];		/* volume label */
130     u_int8_t type[8];		/* file system type */
131 };
132 
133 struct de {
134     u_int8_t namext[11];	/* name and extension */
135     u_int8_t attr;		/* attributes */
136     u_int8_t rsvd[10];		/* reserved */
137     u_int8_t time[2];		/* creation time */
138     u_int8_t date[2];		/* creation date */
139     u_int8_t clus[2];		/* starting cluster */
140     u_int8_t size[4];		/* size */
141 };
142 
143 struct bpb {
144     u_int bps;			/* bytes per sector */
145     u_int spc;			/* sectors per cluster */
146     u_int res;			/* reserved sectors */
147     u_int nft;			/* number of FATs */
148     u_int rde;			/* root directory entries */
149     u_int sec;			/* total sectors */
150     u_int mid;			/* media descriptor */
151     u_int spf;			/* sectors per FAT */
152     u_int spt;			/* sectors per track */
153     u_int hds;			/* drive heads */
154     u_int hid;			/* hidden sectors */
155     u_int bsec;			/* big total sectors */
156     u_int bspf;			/* big sectors per FAT */
157     u_int rdcl;			/* root directory start cluster */
158     u_int infs;			/* file system info sector */
159     u_int bkbs;			/* backup boot sector */
160 };
161 
162 #define INIT(a, b, c, d, e, f, g, h, i, j) \
163     { .bps = a, .spc = b, .res = c, .nft = d, .rde = e, \
164       .sec = f, .mid = g, .spf = h, .spt = i, .hds = j, }
165 static struct {
166     const char *name;
167     struct bpb bpb;
168 } stdfmt[] = {
169     {"160",  INIT(512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1)},
170     {"180",  INIT(512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1)},
171     {"320",  INIT(512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2)},
172     {"360",  INIT(512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2)},
173     {"640",  INIT(512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2)},
174     {"720",  INIT(512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2)},
175     {"1200", INIT(512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2)},
176     {"1232", INIT(1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2)},
177     {"1440", INIT(512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2)},
178     {"2880", INIT(512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2)}
179 };
180 
181 static u_int8_t bootcode[] = {
182     0xfa,			/* cli		    */
183     0x31, 0xc0,			/* xor	   ax,ax    */
184     0x8e, 0xd0,			/* mov	   ss,ax    */
185     0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
186     0xfb,			/* sti		    */
187     0x8e, 0xd8,			/* mov	   ds,ax    */
188     0xe8, 0x00, 0x00,		/* call    $ + 3    */
189     0x5e,			/* pop	   si	    */
190     0x83, 0xc6, 0x19,		/* add	   si,+19h  */
191     0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
192     0xfc,			/* cld		    */
193     0xac,			/* lodsb	    */
194     0x84, 0xc0,			/* test    al,al    */
195     0x74, 0x06,			/* jz	   $ + 8    */
196     0xb4, 0x0e,			/* mov	   ah,0eh   */
197     0xcd, 0x10,			/* int	   10h	    */
198     0xeb, 0xf5,			/* jmp	   $ - 9    */
199     0x30, 0xe4,			/* xor	   ah,ah    */
200     0xcd, 0x16,			/* int	   16h	    */
201     0xcd, 0x19,			/* int	   19h	    */
202     0x0d, 0x0a,
203     'N', 'o', 'n', '-', 's', 'y', 's', 't',
204     'e', 'm', ' ', 'd', 'i', 's', 'k',
205     0x0d, 0x0a,
206     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
207     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
208     ' ', 'r', 'e', 'b', 'o', 'o', 't',
209     0x0d, 0x0a,
210     0
211 };
212 
213 static int got_siginfo = 0; /* received a SIGINFO */
214 
215 static int getstdfmt(const char *, struct bpb *);
216 static int getbpbinfo(int, const char *, const char *, int, struct bpb *, int);
217 static void print_bpb(struct bpb *);
218 static int ckgeom(const char *, u_int, const char *);
219 static int oklabel(const char *);
220 static void mklabel(u_int8_t *, const char *);
221 static void setstr(u_int8_t *, const char *, size_t);
222 static void infohandler(int sig);
223 
224 int
225 mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
226 {
227     char buf[MAXPATHLEN];
228     struct stat sb;
229     struct timeval tv;
230     struct bpb bpb;
231     struct tm *tm;
232     struct bs *bs;
233     struct bsbpb *bsbpb;
234     struct bsxbpb *bsxbpb;
235     struct bsx *bsx;
236     struct de *de;
237     u_int8_t *img;
238     const char *bname;
239     ssize_t n;
240     time_t now;
241     u_int bss, rds, cls, dir, lsn, x, x1, x2;
242     int ch, fd, fd1;
243     struct msdos_options o = *op;
244     int oflags = O_RDWR | O_CREAT;
245 
246     if (o.block_size && o.sectors_per_cluster) {
247 	warnx("Cannot specify both block size and sectors per cluster");
248 	return -1;
249     }
250     if (o.OEM_string && strlen(o.OEM_string) > 8) {
251 	warnx("%s: bad OEM string", o.OEM_string);
252 	return -1;
253     }
254     if (o.create_size) {
255 	if (o.offset == 0)
256 		oflags |= O_TRUNC;
257 	fd = open(fname, oflags, 0644);
258 	if (fd == -1) {
259 	    warnx("failed to create %s", fname);
260 	    return -1;
261 	}
262 	(void)lseek(fd, o.create_size - 1, SEEK_SET);
263 	if (write(fd, "\0", 1) != 1) {
264 	    warn("failed to set file size");
265 	    return -1;
266 	}
267 	(void)lseek(fd, 0, SEEK_SET);
268     } else if ((fd = open(fname, O_RDWR)) == -1 ||
269 	fstat(fd, &sb)) {
270 	warn("%s", fname);
271 	return -1;
272     }
273     if (!S_ISCHR(sb.st_mode) && !o.create_size) {
274 	warnx("warning, %s is not a character device", fname);
275 	return -1;
276     }
277     if (o.offset && o.offset != lseek(fd, o.offset, SEEK_SET)) {
278 	warnx("cannot seek to %jd", (intmax_t)o.offset);
279 	return -1;
280     }
281     memset(&bpb, 0, sizeof(bpb));
282     if (o.floppy) {
283 	if (getstdfmt(o.floppy, &bpb) == -1)
284 	    return -1;
285 	bpb.bsec = bpb.sec;
286 	bpb.sec = 0;
287 	bpb.bspf = bpb.spf;
288 	bpb.spf = 0;
289     }
290     if (o.drive_heads)
291 	bpb.hds = o.drive_heads;
292     if (o.sectors_per_track)
293 	bpb.spt = o.sectors_per_track;
294     if (o.bytes_per_sector)
295 	bpb.bps = o.bytes_per_sector;
296     if (o.size)
297 	bpb.bsec = o.size;
298     if (o.hidden_sectors_set)
299 	bpb.hid = o.hidden_sectors;
300     if (!(o.floppy || (o.drive_heads && o.sectors_per_track &&
301 	o.bytes_per_sector && o.size && o.hidden_sectors_set))) {
302 	if (getbpbinfo(fd, fname, dtype, o.hidden_sectors_set, &bpb,
303 	    o.create_size != 0) == -1)
304 	    return -1;
305 	bpb.bsec -= (o.offset / bpb.bps);
306 	if (bpb.spc == 0) {     /* set defaults */
307 	    /* minimum cluster size */
308 	    switch (o.fat_type) {
309 	    case 12:
310 		bpb.spc = 1;            /* use 512 bytes */
311 		x = 2;                  /* up to 2MB */
312 		break;
313 	    case 16:
314 		bpb.spc = 1;            /* use 512 bytes */
315 		x = 32;                 /* up to 32MB */
316 		break;
317 	    default:
318 		bpb.spc = 8;            /* use 4k */
319 		x = 8192;               /* up to 8GB */
320 		break;
321 	    }
322 	    x1 = howmany(bpb.bsec, (1048576 / 512)); /* -> MB */
323 	    while (bpb.spc < 128 && x < x1) {
324 		x *= 2;
325 		bpb.spc *= 2;
326 	    }
327 	}
328     }
329 
330     if (o.volume_label && !oklabel(o.volume_label)) {
331 	warnx("%s: bad volume label", o.volume_label);
332 	return -1;
333     }
334 
335     switch (o.fat_type) {
336     case 0:
337 	if (o.floppy)
338 	    o.fat_type = 12;
339 	else if (!o.directory_entries && (o.info_sector || o.backup_sector))
340 	    o.fat_type = 32;
341 	break;
342     case 12:
343     case 16:
344 	if (o.info_sector) {
345 	    warnx("Cannot specify info sector with FAT%u", o.fat_type);
346 	    return -1;
347 	}
348 	if (o.backup_sector) {
349 	    warnx("Cannot specify backup sector with FAT%u", o.fat_type);
350 	    return -1;
351 	}
352 	break;
353     case 32:
354 	if (o.directory_entries) {
355 	    warnx("Cannot specify directory entries with FAT32");
356 	    return -1;
357 	}
358 	break;
359     default:
360 	warnx("%d: bad FAT type", o.fat_type);
361 	return -1;
362     }
363     if (!powerof2(bpb.bps)) {
364 	warnx("bytes/sector (%u) is not a power of 2", bpb.bps);
365 	return -1;
366     }
367     if (bpb.bps < MINBPS) {
368 	warnx("bytes/sector (%u) is too small; minimum is %u",
369 	     bpb.bps, MINBPS);
370 	return -1;
371     }
372 
373     if (o.floppy && o.fat_type == 32)
374 	bpb.rde = 0;
375     if (o.block_size) {
376 	if (!powerof2(o.block_size)) {
377 	    warnx("block size (%u) is not a power of 2", o.block_size);
378 	    return -1;
379 	}
380 	if (o.block_size < bpb.bps) {
381 	    warnx("block size (%u) is too small; minimum is %u",
382 		o.block_size, bpb.bps);
383 	    return -1;
384 	}
385 	if (o.block_size > bpb.bps * MAXSPC) {
386 	    warnx("block size (%u) is too large; maximum is %u",
387 		o.block_size, bpb.bps * MAXSPC);
388 	    return -1;
389 	}
390 	bpb.spc = o.block_size / bpb.bps;
391     }
392     if (o.sectors_per_cluster) {
393 	if (!powerof2(o.sectors_per_cluster)) {
394 	    warnx("sectors/cluster (%u) is not a power of 2",
395 		o.sectors_per_cluster);
396 	    return -1;
397 	}
398 	bpb.spc = o.sectors_per_cluster;
399     }
400     if (o.reserved_sectors)
401 	bpb.res = o.reserved_sectors;
402     if (o.num_FAT) {
403 	if (o.num_FAT > MAXNFT) {
404 	    warnx("number of FATs (%u) is too large; maximum is %u",
405 		 o.num_FAT, MAXNFT);
406 	    return -1;
407 	}
408 	bpb.nft = o.num_FAT;
409     }
410     if (o.directory_entries)
411 	bpb.rde = o.directory_entries;
412     if (o.media_descriptor_set) {
413 	if (o.media_descriptor < 0xf0) {
414 	    warnx("illegal media descriptor (%#x)", o.media_descriptor);
415 	    return -1;
416 	}
417 	bpb.mid = o.media_descriptor;
418     }
419     if (o.sectors_per_fat)
420 	bpb.bspf = o.sectors_per_fat;
421     if (o.info_sector)
422 	bpb.infs = o.info_sector;
423     if (o.backup_sector)
424 	bpb.bkbs = o.backup_sector;
425     bss = 1;
426     bname = NULL;
427     fd1 = -1;
428     if (o.bootstrap) {
429 	bname = o.bootstrap;
430 	if (!strchr(bname, '/')) {
431 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
432 	    if (!(bname = strdup(buf))) {
433 		warn(NULL);
434 		return -1;
435 	    }
436 	}
437 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb)) {
438 	    warn("%s", bname);
439 	    return -1;
440 	}
441 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
442 	    sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16) {
443 	    warnx("%s: inappropriate file type or format", bname);
444 	    return -1;
445 	}
446 	bss = sb.st_size / bpb.bps;
447     }
448     if (!bpb.nft)
449 	bpb.nft = 2;
450     if (!o.fat_type) {
451 	if (bpb.bsec < (bpb.res ? bpb.res : bss) +
452 	    howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
453 		    ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
454 	    bpb.nft +
455 	    howmany(bpb.rde ? bpb.rde : DEFRDE,
456 		    bpb.bps / sizeof(struct de)) +
457 	    (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
458 	    (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
459 	    o.fat_type = 12;
460 	else if (bpb.rde || bpb.bsec <
461 		 (bpb.res ? bpb.res : bss) +
462 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
463 		 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
464 		 (MAXCLS16 + 1) *
465 		 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
466 	    o.fat_type = 16;
467 	else
468 	    o.fat_type = 32;
469     }
470     x = bss;
471     if (o.fat_type == 32) {
472 	if (!bpb.infs) {
473 	    if (x == MAXU16 || x == bpb.bkbs) {
474 		warnx("no room for info sector");
475 		return -1;
476 	    }
477 	    bpb.infs = x;
478 	}
479 	if (bpb.infs != MAXU16 && x <= bpb.infs)
480 	    x = bpb.infs + 1;
481 	if (!bpb.bkbs) {
482 	    if (x == MAXU16) {
483 		warnx("no room for backup sector");
484 		return -1;
485 	    }
486 	    bpb.bkbs = x;
487 	} else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs) {
488 	    warnx("backup sector would overwrite info sector");
489 	    return -1;
490 	}
491 	if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
492 	    x = bpb.bkbs + 1;
493     }
494     if (!bpb.res)
495 	bpb.res = o.fat_type == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x;
496     else if (bpb.res < x) {
497 	warnx("too few reserved sectors (need %d have %d)", x, bpb.res);
498 	return -1;
499     }
500     if (o.fat_type != 32 && !bpb.rde)
501 	bpb.rde = DEFRDE;
502     rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
503     if (!bpb.spc)
504 	for (bpb.spc = howmany(o.fat_type == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
505 	     bpb.spc < MAXSPC &&
506 	     bpb.res +
507 	     howmany((RESFTE + maxcls(o.fat_type)) * (o.fat_type / BPN),
508 		     bpb.bps * NPB) * bpb.nft +
509 	     rds +
510 	     (u_int64_t)(maxcls(o.fat_type) + 1) * bpb.spc <= bpb.bsec;
511 	     bpb.spc <<= 1);
512     if (o.fat_type != 32 && bpb.bspf > MAXU16) {
513 	warnx("too many sectors/FAT for FAT12/16");
514 	return -1;
515     }
516     x1 = bpb.res + rds;
517     x = bpb.bspf ? bpb.bspf : 1;
518     if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec) {
519 	warnx("meta data exceeds file system size");
520 	return -1;
521     }
522     x1 += x * bpb.nft;
523     x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
524 	(bpb.spc * bpb.bps * NPB + o.fat_type / BPN * bpb.nft);
525     x2 = howmany((RESFTE + MIN(x, maxcls(o.fat_type))) * (o.fat_type / BPN),
526 		 bpb.bps * NPB);
527     if (!bpb.bspf) {
528 	bpb.bspf = x2;
529 	x1 += (bpb.bspf - 1) * bpb.nft;
530     }
531     cls = (bpb.bsec - x1) / bpb.spc;
532     x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (o.fat_type / BPN) - RESFTE;
533     if (cls > x)
534 	cls = x;
535     if (bpb.bspf < x2) {
536 	warnx("warning: sectors/FAT limits file system to %u clusters",
537 	      cls);
538 	return -1;
539     }
540     if (cls < mincls(o.fat_type)) {
541 	warnx("%u clusters too few clusters for FAT%u, need %u", cls,
542 	    o.fat_type, mincls(o.fat_type));
543 	return -1;
544     }
545     if (cls > maxcls(o.fat_type)) {
546 	cls = maxcls(o.fat_type);
547 	bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
548 	warnx("warning: FAT type limits file system to %u sectors",
549 	      bpb.bsec);
550 	return -1;
551     }
552     printf("%s: %u sector%s in %u FAT%u cluster%s "
553 	   "(%u bytes/cluster)\n", fname, cls * bpb.spc,
554 	   cls * bpb.spc == 1 ? "" : "s", cls, o.fat_type,
555 	   cls == 1 ? "" : "s", bpb.bps * bpb.spc);
556     if (!bpb.mid)
557 	bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
558     if (o.fat_type == 32)
559 	bpb.rdcl = RESFTE;
560     if (bpb.hid + bpb.bsec <= MAXU16) {
561 	bpb.sec = bpb.bsec;
562 	bpb.bsec = 0;
563     }
564     if (o.fat_type != 32) {
565 	bpb.spf = bpb.bspf;
566 	bpb.bspf = 0;
567     }
568     ch = 0;
569     if (o.fat_type == 12)
570 	ch = 1;			/* 001 Primary DOS with 12 bit FAT */
571     else if (o.fat_type == 16) {
572 	if (bpb.bsec == 0)
573 	    ch = 4;		/* 004 Primary DOS with 16 bit FAT <32M */
574 	else
575 	    ch = 6;		/* 006 Primary 'big' DOS, 16-bit FAT (> 32MB) */
576 				/*
577 				 * XXX: what about:
578 				 * 014 DOS (16-bit FAT) - LBA
579 				 *  ?
580 				 */
581     } else if (o.fat_type == 32) {
582 	ch = 11;		/* 011 Primary DOS with 32 bit FAT */
583 				/*
584 				 * XXX: what about:
585 				 * 012 Primary DOS with 32 bit FAT - LBA
586 				 *  ?
587 				 */
588     }
589     if (ch != 0)
590 	printf("MBR type: %d\n", ch);
591     print_bpb(&bpb);
592 
593     gettimeofday(&tv, NULL);
594     now = tv.tv_sec;
595     tm = localtime(&now);
596     img = emalloc(bpb.bps);
597     dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
598     signal(SIGINFO, infohandler);
599     for (lsn = 0; lsn < dir + (o.fat_type == 32 ? bpb.spc : rds); lsn++) {
600         if (got_siginfo) {
601             fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
602                 fname,lsn,(dir + (o.fat_type == 32 ? bpb.spc : rds)),
603                 (lsn*100)/(dir + (o.fat_type == 32 ? bpb.spc : rds)));
604             got_siginfo = 0;
605         }
606         x = lsn;
607         if (o.bootstrap &&
608             o.fat_type == 32 && bpb.bkbs != MAXU16 &&
609             bss <= bpb.bkbs && x >= bpb.bkbs) {
610             x -= bpb.bkbs;
611             if (!x && lseek(fd1, o.offset, SEEK_SET)) {
612                 warn("%s", bname);
613                 return -1;
614             }
615         }
616         if (o.bootstrap && x < bss) {
617             if ((n = read(fd1, img, bpb.bps)) == -1) {
618                 warn("%s", bname);
619                 return -1;
620             }
621             if ((size_t)n != bpb.bps) {
622                 warnx("%s: can't read sector %u", bname, x);
623                 return -1;
624             }
625         } else
626             memset(img, 0, bpb.bps);
627         if (!lsn ||
628           (o.fat_type == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
629             x1 = sizeof(struct bs);
630             bsbpb = (struct bsbpb *)(img + x1);
631             mk2(bsbpb->bps, bpb.bps);
632             mk1(bsbpb->spc, bpb.spc);
633             mk2(bsbpb->res, bpb.res);
634             mk1(bsbpb->nft, bpb.nft);
635             mk2(bsbpb->rde, bpb.rde);
636             mk2(bsbpb->sec, bpb.sec);
637             mk1(bsbpb->mid, bpb.mid);
638             mk2(bsbpb->spf, bpb.spf);
639             mk2(bsbpb->spt, bpb.spt);
640             mk2(bsbpb->hds, bpb.hds);
641             mk4(bsbpb->hid, bpb.hid);
642             mk4(bsbpb->bsec, bpb.bsec);
643             x1 += sizeof(struct bsbpb);
644             if (o.fat_type == 32) {
645                 bsxbpb = (struct bsxbpb *)(img + x1);
646                 mk4(bsxbpb->bspf, bpb.bspf);
647                 mk2(bsxbpb->xflg, 0);
648                 mk2(bsxbpb->vers, 0);
649                 mk4(bsxbpb->rdcl, bpb.rdcl);
650                 mk2(bsxbpb->infs, bpb.infs);
651                 mk2(bsxbpb->bkbs, bpb.bkbs);
652                 x1 += sizeof(struct bsxbpb);
653             }
654             bsx = (struct bsx *)(img + x1);
655             mk1(bsx->sig, 0x29);
656             if (o.volume_id_set)
657                 x = o.volume_id;
658             else
659                 x = (((u_int)(1 + tm->tm_mon) << 8 |
660                       (u_int)tm->tm_mday) +
661                      ((u_int)tm->tm_sec << 8 |
662                       (u_int)(tv.tv_usec / 10))) << 16 |
663                     ((u_int)(1900 + tm->tm_year) +
664                      ((u_int)tm->tm_hour << 8 |
665                       (u_int)tm->tm_min));
666             mk4(bsx->volid, x);
667             mklabel(bsx->label, o.volume_label ? o.volume_label : "NO NAME");
668             snprintf(buf, sizeof(buf), "FAT%u", o.fat_type);
669             setstr(bsx->type, buf, sizeof(bsx->type));
670             if (!o.bootstrap) {
671                 x1 += sizeof(struct bsx);
672                 bs = (struct bs *)img;
673                 mk1(bs->jmp[0], 0xeb);
674                 mk1(bs->jmp[1], x1 - 2);
675                 mk1(bs->jmp[2], 0x90);
676                 setstr(bs->oem, o.OEM_string ? o.OEM_string : "NetBSD",
677                        sizeof(bs->oem));
678                 memcpy(img + x1, bootcode, sizeof(bootcode));
679                 mk2(img + MINBPS - 2, DOSMAGIC);
680             }
681         } else if (o.fat_type == 32 && bpb.infs != MAXU16 &&
682                    (lsn == bpb.infs ||
683                     (bpb.bkbs != MAXU16 &&
684                      lsn == bpb.bkbs + bpb.infs))) {
685             mk4(img, 0x41615252);
686             mk4(img + MINBPS - 28, 0x61417272);
687             mk4(img + MINBPS - 24, 0xffffffff);
688             mk4(img + MINBPS - 20, 0xffffffff);
689             mk2(img + MINBPS - 2, DOSMAGIC);
690         } else if (lsn >= bpb.res && lsn < dir &&
691                    !((lsn - bpb.res) %
692                      (bpb.spf ? bpb.spf : bpb.bspf))) {
693             mk1(img[0], bpb.mid);
694             for (x = 1; x < o.fat_type * (o.fat_type == 32 ? 3U : 2U) / 8U; x++)
695                 mk1(img[x], o.fat_type == 32 && x % 4 == 3 ? 0x0f : 0xff);
696         } else if (lsn == dir && o.volume_label) {
697             de = (struct de *)img;
698             mklabel(de->namext, o.volume_label);
699             mk1(de->attr, 050);
700             x = (u_int)tm->tm_hour << 11 |
701                 (u_int)tm->tm_min << 5 |
702                 (u_int)tm->tm_sec >> 1;
703             mk2(de->time, x);
704             x = (u_int)(tm->tm_year - 80) << 9 |
705                 (u_int)(tm->tm_mon + 1) << 5 |
706                 (u_int)tm->tm_mday;
707             mk2(de->date, x);
708         }
709         if ((n = write(fd, img, bpb.bps)) == -1) {
710             warn("%s", fname);
711             return -1;
712         }
713         if ((size_t)n != bpb.bps) {
714             warnx("%s: can't write sector %u", fname, lsn);
715             return -1;
716         }
717     }
718     return 0;
719 }
720 
721 
722 /*
723  * Get a standard format.
724  */
725 static int
726 getstdfmt(const char *fmt, struct bpb *bpb)
727 {
728     u_int x, i;
729 
730     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
731     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
732     if (i == x) {
733 	warnx("%s: unknown standard format", fmt);
734 	return -1;
735     }
736     *bpb = stdfmt[i].bpb;
737     return 0;
738 }
739 
740 /*
741  * Get disk slice, partition, and geometry information.
742  */
743 static int
744 getbpbinfo(int fd, const char *fname, const char *dtype, int iflag,
745     struct bpb *bpb, int create)
746 {
747     const char *s1, *s2;
748     int part;
749 
750     part = -1;
751     s1 = fname;
752     if ((s2 = strrchr(s1, '/')))
753 	s1 = s2 + 1;
754     for (s2 = s1; *s2 && !isdigit((unsigned char)*s2); s2++);
755     if (!*s2 || s2 == s1)
756 	s2 = NULL;
757     else
758 	while (isdigit((unsigned char)*++s2));
759     s1 = s2;
760 
761     if (((part != -1) && ((!iflag && part != -1) || !bpb->bsec)) ||
762 	!bpb->bps || !bpb->spt || !bpb->hds) {
763 	u_int sector_size;
764 	u_int nsectors;
765 	u_int ntracks;
766 	u_int size;
767 	{
768 	    struct stat st;
769 
770 	    if (fstat(fd, &st) == -1) {
771 		warnx("Can't get disk size for `%s'", fname);
772 		return -1;
773 	    }
774 	    /* create a fake geometry for a file image */
775 	    sector_size = 512;
776 	    nsectors = 63;
777 	    ntracks = 255;
778 	    size = st.st_size / sector_size;
779 	}
780 	if (!bpb->bps) {
781 	    if (ckgeom(fname, sector_size, "bytes/sector") == -1)
782 		return -1;
783 	    bpb->bps = sector_size;
784 	}
785 
786 	if (nsectors > 63) {
787 		/*
788 		 * The kernel doesn't accept BPB with spt > 63.
789 		 * (see sys/fs/msdosfs/msdosfs_vfsops.c:msdosfs_mountfs())
790 		 * If values taken from disklabel don't match these
791 		 * restrictions, use popular BIOS default values instead.
792 		 */
793 		nsectors = 63;
794 	}
795 	if (!bpb->spt) {
796 	    if (ckgeom(fname, nsectors, "sectors/track") == -1)
797 		return -1;
798 	    bpb->spt = nsectors;
799 	}
800 	if (!bpb->hds) {
801 	    if (ckgeom(fname, ntracks, "drive heads") == -1)
802 		return -1;
803 	    bpb->hds = ntracks;
804 	}
805 	if (!bpb->bsec)
806 	    bpb->bsec = size;
807     }
808     return 0;
809 }
810 
811 /*
812  * Print out BPB values.
813  */
814 static void
815 print_bpb(struct bpb *bpb)
816 {
817     printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
818 	   bpb->nft);
819     if (bpb->rde)
820 	printf(" rde=%u", bpb->rde);
821     if (bpb->sec)
822 	printf(" sec=%u", bpb->sec);
823     printf(" mid=%#x", bpb->mid);
824     if (bpb->spf)
825 	printf(" spf=%u", bpb->spf);
826     printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
827     if (bpb->bsec)
828 	printf(" bsec=%u", bpb->bsec);
829     if (!bpb->spf) {
830 	printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
831 	printf(" infs=");
832 	printf(bpb->infs == MAXU16 ? "%#x" : "%u", bpb->infs);
833 	printf(" bkbs=");
834 	printf(bpb->bkbs == MAXU16 ? "%#x" : "%u", bpb->bkbs);
835     }
836     printf("\n");
837 }
838 
839 /*
840  * Check a disk geometry value.
841  */
842 static int
843 ckgeom(const char *fname, u_int val, const char *msg)
844 {
845     if (!val) {
846 	warnx("%s: no default %s", fname, msg);
847 	return -1;
848     }
849     if (val > MAXU16) {
850 	warnx("%s: illegal %s", fname, msg);
851 	return -1;
852     }
853     return 0;
854 }
855 /*
856  * Check a volume label.
857  */
858 static int
859 oklabel(const char *src)
860 {
861     int c, i;
862 
863     for (i = 0; i <= 11; i++) {
864 	c = (u_char)*src++;
865 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
866 	    break;
867     }
868     return i && !c;
869 }
870 
871 /*
872  * Make a volume label.
873  */
874 static void
875 mklabel(u_int8_t *dest, const char *src)
876 {
877     int c, i;
878 
879     for (i = 0; i < 11; i++) {
880 	c = *src ? toupper((unsigned char)*src++) : ' ';
881 	*dest++ = !i && c == '\xe5' ? 5 : c;
882     }
883 }
884 
885 /*
886  * Copy string, padding with spaces.
887  */
888 static void
889 setstr(u_int8_t *dest, const char *src, size_t len)
890 {
891     while (len--)
892 	*dest++ = *src ? *src++ : ' ';
893 }
894 
895 static void
896 infohandler(int sig)
897 {
898     got_siginfo = 1;
899 }
900