newfs_msdos.c revision 37759
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
29static const char rcsid[] =
30	"$Id: newfs_msdos.c,v 1.3 1998/07/16 12:24:51 rnordier Exp $";
31#endif /* not lint */
32
33#include <sys/param.h>
34#include <sys/stat.h>
35#include <sys/diskslice.h>
36#include <sys/disklabel.h>
37#include <sys/mount.h>
38
39#include <ctype.h>
40#include <err.h>
41#include <errno.h>
42#include <fcntl.h>
43#include <paths.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48
49#define MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
50#define BPN	  4		/* bits per nibble */
51#define NPB	  2		/* nibbles per byte */
52
53#define DOSMAGIC  0xaa55	/* DOS magic number */
54#define MINBPS	  128		/* minimum bytes per sector */
55#define MAXSPC	  128		/* maximum sectors per cluster */
56#define MAXNFT	  16		/* maximum number of FATs */
57#define DEFBLK	  4096		/* default block size */
58#define DEFBLK16  2048		/* default block size FAT16 */
59#define DEFRDE	  512		/* default root directory entries */
60#define RESFTE	  2		/* reserved FAT entries */
61#define MINCLS12  1		/* minimum FAT12 clusters */
62#define MINCLS16  0x1000	/* minimum FAT16 clusters */
63#define MINCLS32  2		/* minimum FAT32 clusters */
64#define MAXCLS12  0xfed 	/* maximum FAT12 clusters */
65#define MAXCLS16  0xfff5	/* maximum FAT16 clusters */
66#define MAXCLS32  0xffffff5	/* maximum FAT32 clusters */
67
68#define mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
69		      (fat) == 16 ? MINCLS16 :	\
70				    MINCLS32)
71
72#define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
73		      (fat) == 16 ? MAXCLS16 :	\
74				    MAXCLS32)
75
76#define mk1(p, x)				\
77    (p) = (u_int8_t)(x)
78
79#define mk2(p, x)				\
80    (p)[0] = (u_int8_t)(x),			\
81    (p)[1] = (u_int8_t)((x) >> 010)
82
83#define mk4(p, x)				\
84    (p)[0] = (u_int8_t)(x),			\
85    (p)[1] = (u_int8_t)((x) >> 010),		\
86    (p)[2] = (u_int8_t)((x) >> 020),		\
87    (p)[3] = (u_int8_t)((x) >> 030)
88
89#define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
90#define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
91#define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
92#define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
93
94struct bs {
95    u_int8_t jmp[3];		/* bootstrap entry point */
96    u_int8_t oem[8];		/* OEM name and version */
97};
98
99struct 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
114struct 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
124struct 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
133struct 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
143struct 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
162static struct {
163    const char *name;
164    struct bpb bpb;
165} stdfmt[] = {
166    {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1}},
167    {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1}},
168    {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2}},
169    {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2}},
170    {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2}},
171    {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2}},
172    {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2}},
173    {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2}}
174};
175
176static u_int8_t bootcode[] = {
177    0xfa,			/* cli		    */
178    0x31, 0xc0, 		/* xor	   ax,ax    */
179    0x8e, 0xd0, 		/* mov	   ss,ax    */
180    0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
181    0xfb,			/* sti		    */
182    0x8e, 0xd8, 		/* mov	   ds,ax    */
183    0xe8, 0x00, 0x00,		/* call    $ + 3    */
184    0x5e,			/* pop	   si	    */
185    0x83, 0xc6, 0x19,		/* add	   si,+19h  */
186    0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
187    0xfc,			/* cld		    */
188    0xac,			/* lodsb	    */
189    0x84, 0xc0, 		/* test    al,al    */
190    0x74, 0x06, 		/* jz	   $ + 8    */
191    0xb4, 0x0e, 		/* mov	   ah,0eh   */
192    0xcd, 0x10, 		/* int	   10h	    */
193    0xeb, 0xf5, 		/* jmp	   $ - 9    */
194    0x30, 0xe4, 		/* xor	   ah,ah    */
195    0xcd, 0x16, 		/* int	   16h	    */
196    0xcd, 0x19, 		/* int	   19h	    */
197    0x0d, 0x0a,
198    'N', 'o', 'n', '-', 's', 'y', 's', 't',
199    'e', 'm', ' ', 'd', 'i', 's', 'k',
200    0x0d, 0x0a,
201    'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
202    'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
203    ' ', 'r', 'e', 'b', 'o', 'o', 't',
204    0x0d, 0x0a,
205    0
206};
207
208static void check_mounted(const char *, mode_t);
209static void getstdfmt(const char *, struct bpb *);
210static void getdiskinfo(int, const char *, const char *, int,
211			struct bpb *);
212static void print_bpb(struct bpb *);
213static u_int ckgeom(const char *, u_int, const char *);
214static u_int argtou(const char *, u_int, u_int, const char *);
215static int oklabel(const char *);
216static void mklabel(u_int8_t *, const char *);
217static void setstr(u_int8_t *, const char *, size_t);
218static void usage(void);
219
220/*
221 * Construct a FAT12, FAT16, or FAT32 file system.
222 */
223int
224main(int argc, char *argv[])
225{
226    static char opts[] = "NB:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
227    static const char *opt_B, *opt_L, *opt_O, *opt_f;
228    static u_int opt_F, opt_I, opt_S, opt_a, opt_b, opt_c, opt_e;
229    static u_int opt_h, opt_i, opt_k, opt_m, opt_n, opt_o, opt_r;
230    static u_int opt_s, opt_u;
231    static int opt_N;
232    static int Iflag, mflag, oflag;
233    char buf[MAXPATHLEN];
234    struct stat sb;
235    struct timeval tv;
236    struct bpb bpb;
237    struct tm *tm;
238    struct bs *bs;
239    struct bsbpb *bsbpb;
240    struct bsxbpb *bsxbpb;
241    struct bsx *bsx;
242    struct de *de;
243    u_int8_t *img;
244    const char *fname, *dtype, *bname;
245    ssize_t n;
246    u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
247    int ch, fd, fd1;
248
249    while ((ch = getopt(argc, argv, opts)) != -1)
250	switch (ch) {
251	case 'N':
252	    opt_N = 1;
253	    break;
254	case 'B':
255	    opt_B = optarg;
256	    break;
257	case 'F':
258	    if (strcmp(optarg, "12") &&
259		strcmp(optarg, "16") &&
260		strcmp(optarg, "32"))
261		errx(1, "%s: bad FAT type", optarg);
262	    opt_F = atoi(optarg);
263	    break;
264	case 'I':
265	    opt_I = argto4(optarg, 0, "volume ID");
266	    Iflag = 1;
267	    break;
268	case 'L':
269	    if (!oklabel(optarg))
270		errx(1, "%s: bad volume label", optarg);
271	    opt_L = optarg;
272	    break;
273	case 'O':
274	    if (strlen(optarg) > 8)
275		errx(1, "%s: bad OEM string", optarg);
276	    opt_O = optarg;
277	    break;
278	case 'S':
279	    opt_S = argto2(optarg, 1, "bytes/sector");
280	    break;
281	case 'a':
282	    opt_a = argto4(optarg, 1, "sectors/FAT");
283	    break;
284	case 'b':
285	    opt_b = argtox(optarg, 1, "block size");
286	    opt_c = 0;
287	    break;
288	case 'c':
289	    opt_c = argto1(optarg, 1, "sectors/cluster");
290	    opt_b = 0;
291	    break;
292	case 'e':
293	    opt_e = argto2(optarg, 1, "directory entries");
294	    break;
295	case 'f':
296	    opt_f = optarg;
297	    break;
298	case 'h':
299	    opt_h = argto2(optarg, 1, "drive heads");
300	    break;
301	case 'i':
302	    opt_i = argto2(optarg, 1, "info sector");
303	    break;
304	case 'k':
305	    opt_k = argto2(optarg, 1, "backup sector");
306	    break;
307	case 'm':
308	    opt_m = argto1(optarg, 0, "media descriptor");
309	    mflag = 1;
310	    break;
311	case 'n':
312	    opt_n = argto1(optarg, 1, "number of FATs");
313	    break;
314	case 'o':
315	    opt_o = argto4(optarg, 0, "hidden sectors");
316	    oflag = 1;
317	    break;
318	case 'r':
319	    opt_r = argto2(optarg, 1, "reserved sectors");
320	    break;
321	case 's':
322	    opt_s = argto4(optarg, 1, "file system size");
323	    break;
324	case 'u':
325	    opt_u = argto2(optarg, 1, "sectors/track");
326	    break;
327	default:
328	    usage();
329	}
330    argc -= optind;
331    argv += optind;
332    if (argc < 1 || argc > 2)
333	usage();
334    fname = *argv++;
335    if (!strchr(fname, '/')) {
336	snprintf(buf, sizeof(buf), "%sr%s", _PATH_DEV, fname);
337	if (stat(buf, &sb))
338	    snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
339	if (!(fname = strdup(buf)))
340	    err(1, NULL);
341    }
342    dtype = *argv;
343    if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1 ||
344	fstat(fd, &sb))
345	err(1, "%s", fname);
346    if (!opt_N)
347	check_mounted(fname, sb.st_mode);
348    if (!S_ISCHR(sb.st_mode))
349	warnx("warning: %s is not a character device", fname);
350    memset(&bpb, 0, sizeof(bpb));
351    if (opt_f) {
352	getstdfmt(opt_f, &bpb);
353	bpb.bsec = bpb.sec;
354	bpb.sec = 0;
355	bpb.bspf = bpb.spf;
356	bpb.spf = 0;
357    }
358    if (opt_h)
359	bpb.hds = opt_h;
360    if (opt_u)
361	bpb.spt = opt_u;
362    if (opt_S)
363	bpb.bps = opt_S;
364    if (opt_s)
365	bpb.bsec = opt_s;
366    if (oflag)
367	bpb.hid = opt_o;
368    if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag)))
369	getdiskinfo(fd, fname, dtype, oflag, &bpb);
370    if (!powerof2(bpb.bps))
371	errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
372    if (bpb.bps < MINBPS)
373	errx(1, "bytes/sector (%u) is too small; minimum is %u",
374	     bpb.bps, MINBPS);
375    if (!(fat = opt_F))
376	if (opt_f)
377	    fat = 12;
378	else if (!opt_e && (opt_i || opt_k))
379	    fat = 32;
380    if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
381	errx(1, "-%c is not a legal FAT%s option",
382	     fat == 32 ? 'e' : opt_i ? 'i' : 'k',
383	     fat == 32 ? "32" : "12/16");
384    if (opt_f && fat == 32)
385	bpb.rde = 0;
386    if (opt_b) {
387	if (!powerof2(opt_b))
388	    errx(1, "block size (%u) is not a power of 2", opt_b);
389	if (opt_b < bpb.bps)
390	    errx(1, "block size (%u) is too small; minimum is %u",
391		 opt_b, bpb.bps);
392	if (opt_b > bpb.bps * MAXSPC)
393	    errx(1, "block size (%u) is too large; maximum is %u",
394		 opt_b, bpb.bps * MAXSPC);
395	bpb.spc = opt_b / bpb.bps;
396    }
397    if (opt_c) {
398	if (!powerof2(opt_c))
399	    errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
400	bpb.spc = opt_c;
401    }
402    if (opt_r)
403	bpb.res = opt_r;
404    if (opt_n) {
405	if (opt_n > MAXNFT)
406	    errx(1, "number of FATs (%u) is too large; maximum is %u",
407		 opt_n, MAXNFT);
408	bpb.nft = opt_n;
409    }
410    if (opt_e)
411	bpb.rde = opt_e;
412    if (mflag) {
413	if (opt_m < 0xf0)
414	    errx(1, "illegal media descriptor (0x%x)", opt_m);
415	bpb.mid = opt_m;
416    }
417    if (opt_a)
418	bpb.bspf = opt_a;
419    if (opt_i)
420	bpb.infs = opt_i;
421    if (opt_k)
422	bpb.bkbs = opt_k;
423    bss = 1;
424    bname = NULL;
425    fd1 = -1;
426    if (opt_B) {
427	bname = opt_B;
428	if (!strchr(bname, '/')) {
429	    snprintf(buf, sizeof(buf), "/usr/mdec/%s", bname);
430	    if (!(bname = strdup(buf)))
431		err(1, NULL);
432	}
433	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
434	    err(1, "%s", bname);
435	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
436	    sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
437	    errx(1, "%s: inappropriate file type or format", bname);
438	bss = sb.st_size / bpb.bps;
439    }
440    if (!bpb.nft)
441	bpb.nft = 2;
442    if (!fat)
443	if (bpb.bsec < (bpb.res ? bpb.res : bss) +
444	    howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
445		    ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
446	    bpb.nft +
447	    howmany(bpb.rde ? bpb.rde : DEFRDE,
448		    bpb.bps / sizeof(struct de)) +
449	    (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
450	    (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
451	    fat = 12;
452	else if (bpb.rde || bpb.bsec <
453		 (bpb.res ? bpb.res : bss) +
454		 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
455		 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
456		 (MAXCLS16 + 1) *
457		 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
458	    fat = 16;
459	else
460	    fat = 32;
461    x = bss;
462    if (fat == 32) {
463	if (!bpb.infs) {
464	    if (x == MAXU16 || x == bpb.bkbs)
465		errx(1, "no room for info sector");
466	    bpb.infs = x;
467	}
468	if (bpb.infs != MAXU16 && x <= bpb.infs)
469	    x = bpb.infs + 1;
470	if (!bpb.bkbs) {
471	    if (x == MAXU16)
472		errx(1, "no room for backup sector");
473	    bpb.bkbs = x;
474	} else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
475	    errx(1, "backup sector would overwrite info sector");
476	if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
477	    x = bpb.bkbs + 1;
478    }
479    if (!bpb.res)
480	bpb.res = fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x;
481    else if (bpb.res < x)
482	errx(1, "too few reserved sectors");
483    if (fat != 32 && !bpb.rde)
484	bpb.rde = DEFRDE;
485    rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
486    if (!bpb.spc)
487	for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
488	     bpb.spc < MAXSPC &&
489	     bpb.res +
490	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
491		     bpb.bps * NPB) * bpb.nft +
492	     rds +
493	     (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
494	     bpb.spc <<= 1);
495    if (fat != 32 && bpb.bspf > MAXU16)
496	errx(1, "too many sectors/FAT for FAT12/16");
497    x1 = bpb.res + rds;
498    x = bpb.bspf ? bpb.bspf : 1;
499    if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
500	errx(1, "meta data exceeds file system size");
501    x1 += x * bpb.nft;
502    x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
503	(bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
504    x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
505		 bpb.bps * NPB);
506    if (!bpb.bspf) {
507	bpb.bspf = x2;
508	x1 += (bpb.bspf - 1) * bpb.nft;
509    }
510    cls = (bpb.bsec - x1) / bpb.spc;
511    x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
512    if (cls > x)
513	cls = x;
514    if (bpb.bspf < x2)
515	warnx("warning: sectors/FAT limits file system to %u clusters",
516	      cls);
517    if (cls < mincls(fat))
518	errx(1, "too few clusters for FAT%u", fat);
519    if (cls > maxcls(fat)) {
520	cls = maxcls(fat);
521	bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
522	warnx("warning: FAT type limits file system to %u sectors",
523	      bpb.bsec);
524    }
525    printf("%s: %u sector%s in %u FAT%u cluster%s "
526	   "(%u bytes/cluster)\n", fname, cls * bpb.spc,
527	   cls * bpb.spc == 1 ? "" : "s", cls, fat,
528	   cls == 1 ? "" : "s", bpb.bps * bpb.spc);
529    if (!bpb.mid)
530	bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
531    if (fat == 32)
532	bpb.rdcl = RESFTE;
533    if (bpb.hid + bpb.bsec <= MAXU16) {
534	bpb.sec = bpb.bsec;
535	bpb.bsec = 0;
536    }
537    if (fat != 32) {
538	bpb.spf = bpb.bspf;
539	bpb.bspf = 0;
540    }
541    print_bpb(&bpb);
542    if (!opt_N) {
543	gettimeofday(&tv, NULL);
544	tm = localtime(&tv.tv_sec);
545	if (!(img = malloc(bpb.bps)))
546	    err(1, NULL);
547	dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
548	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
549	    x = lsn;
550	    if (opt_B &&
551		fat == 32 && bpb.bkbs != MAXU16 &&
552		bss <= bpb.bkbs && x >= bpb.bkbs) {
553		x -= bpb.bkbs;
554		if (!x && lseek(fd1, 0, SEEK_SET))
555		    err(1, "%s", bname);
556	    }
557	    if (opt_B && x < bss) {
558		if ((n = read(fd1, img, bpb.bps)) == -1)
559		    err(1, "%s", bname);
560		if (n != bpb.bps)
561		    errx(1, "%s: can't read sector %u", bname, x);
562	    } else
563		memset(img, 0, bpb.bps);
564	    if (!lsn ||
565	      (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
566		x1 = sizeof(struct bs);
567		bsbpb = (struct bsbpb *)(img + x1);
568		mk2(bsbpb->bps, bpb.bps);
569		mk1(bsbpb->spc, bpb.spc);
570		mk2(bsbpb->res, bpb.res);
571		mk1(bsbpb->nft, bpb.nft);
572		mk2(bsbpb->rde, bpb.rde);
573		mk2(bsbpb->sec, bpb.sec);
574		mk1(bsbpb->mid, bpb.mid);
575		mk2(bsbpb->spf, bpb.spf);
576		mk2(bsbpb->spt, bpb.spt);
577		mk2(bsbpb->hds, bpb.hds);
578		mk4(bsbpb->hid, bpb.hid);
579		mk4(bsbpb->bsec, bpb.bsec);
580		x1 += sizeof(struct bsbpb);
581		if (fat == 32) {
582		    bsxbpb = (struct bsxbpb *)(img + x1);
583		    mk4(bsxbpb->bspf, bpb.bspf);
584		    mk2(bsxbpb->xflg, 0);
585		    mk2(bsxbpb->vers, 0);
586		    mk4(bsxbpb->rdcl, bpb.rdcl);
587		    mk2(bsxbpb->infs, bpb.infs);
588		    mk2(bsxbpb->bkbs, bpb.bkbs);
589		    x1 += sizeof(struct bsxbpb);
590		}
591		bsx = (struct bsx *)(img + x1);
592		mk1(bsx->sig, 0x29);
593		if (Iflag)
594		    x = opt_I;
595		else
596		    x = (((u_int)(1 + tm->tm_mon) << 8 |
597			  (u_int)tm->tm_mday) +
598			 ((u_int)tm->tm_sec << 8 |
599			  (u_int)(tv.tv_usec / 10))) << 16 |
600			((u_int)(1900 + tm->tm_year) +
601			 ((u_int)tm->tm_hour << 8 |
602			  (u_int)tm->tm_min));
603		mk4(bsx->volid, x);
604		mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
605		sprintf(buf, "FAT%u", fat);
606		setstr(bsx->type, buf, sizeof(bsx->type));
607		if (!opt_B) {
608		    x1 += sizeof(struct bsx);
609		    bs = (struct bs *)img;
610		    mk1(bs->jmp[0], 0xeb);
611		    mk1(bs->jmp[1], x1 - 2);
612		    mk1(bs->jmp[2], 0x90);
613		    setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
614			   sizeof(bs->oem));
615		    memcpy(img + x1, bootcode, sizeof(bootcode));
616		    mk2(img + bpb.bps - 2, DOSMAGIC);
617		}
618	    } else if (fat == 32 && bpb.infs != MAXU16 &&
619		       (lsn == bpb.infs ||
620			(bpb.bkbs != MAXU16 &&
621			 lsn == bpb.bkbs + bpb.infs))) {
622		mk4(img, 0x41615252);
623		mk4(img + bpb.bps - 28, 0x61417272);
624		mk4(img + bpb.bps - 24, 0xffffffff);
625		mk4(img + bpb.bps - 20, bpb.rdcl);
626		mk2(img + bpb.bps - 2, DOSMAGIC);
627	    } else if (lsn >= bpb.res && lsn < dir &&
628		       !((lsn - bpb.res) %
629			 (bpb.spf ? bpb.spf : bpb.bspf))) {
630		mk1(img[0], bpb.mid);
631		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
632		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
633	    } else if (lsn == dir && opt_L) {
634		de = (struct de *)img;
635		mklabel(de->namext, opt_L);
636		mk1(de->attr, 050);
637		x = (u_int)tm->tm_hour << 11 |
638		    (u_int)tm->tm_min << 5 |
639		    (u_int)tm->tm_sec >> 1;
640		mk2(de->time, x);
641		x = (u_int)(tm->tm_year - 80) << 9 |
642		    (u_int)(tm->tm_mon + 1) << 5 |
643		    (u_int)tm->tm_mday;
644		mk2(de->date, x);
645	    }
646	    if ((n = write(fd, img, bpb.bps)) == -1)
647		err(1, "%s", fname);
648	    if (n != bpb.bps)
649		errx(1, "%s: can't write sector %u", fname, lsn);
650	}
651    }
652    return 0;
653}
654
655/*
656 * Exit with error if file system is mounted.
657 */
658static void
659check_mounted(const char *fname, mode_t mode)
660{
661    struct statfs *mp;
662    const char *s1, *s2;
663    size_t len;
664    int n, r;
665
666    if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
667	err(1, "getmntinfo");
668    len = strlen(_PATH_DEV);
669    s1 = fname;
670    if (!strncmp(s1, _PATH_DEV, len))
671	s1 += len;
672    r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
673    for (; n--; mp++) {
674	s2 = mp->f_mntfromname;
675	if (!strncmp(s2, _PATH_DEV, len))
676	    s2 += len;
677	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
678	    !strcmp(s1, s2))
679	    errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
680    }
681}
682
683/*
684 * Get a standard format.
685 */
686static void
687getstdfmt(const char *fmt, struct bpb *bpb)
688{
689    u_int x, i;
690
691    x = sizeof(stdfmt) / sizeof(stdfmt[0]);
692    for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
693    if (i == x)
694	errx(1, "%s: unknown standard format", fmt);
695    *bpb = stdfmt[i].bpb;
696}
697
698/*
699 * Get disk slice, partition, and geometry information.
700 */
701static void
702getdiskinfo(int fd, const char *fname, const char *dtype, int oflag,
703	    struct bpb *bpb)
704{
705    struct diskslices ds;
706    struct disklabel dl, *lp;
707    const char *s1, *s2;
708    char *s;
709    int slice, part, fd1, i, e;
710
711    slice = part = -1;
712    s1 = fname;
713    if ((s2 = strrchr(s1, '/')))
714	s1 = s2 + 1;
715    for (s2 = s1; *s2 && !isdigit(*s2); s2++);
716    if (!*s2 || s2 == s1)
717	s2 = NULL;
718    else
719	while (isdigit(*++s2));
720    s1 = s2;
721    if (s2 && *s2 == 's') {
722	slice = strtol(s2 + 1, &s, 10);
723	if (slice < 1 || slice > MAX_SLICES - BASE_SLICE)
724	    s2 = NULL;
725	else {
726	    slice = BASE_SLICE + slice - 1;
727	    s2 = s;
728	}
729    }
730    if (s2 && *s2 >= 'a' && *s2 <= 'a' + MAXPARTITIONS - 1) {
731	if (slice == -1)
732	    slice = COMPATIBILITY_SLICE;
733	part = *s2++ - 'a';
734    }
735    if (!s2 || (*s2 && *s2 != '.'))
736	errx(1, "%s: can't figure out partition info", fname);
737    if (slice != -1 && (!oflag || (!bpb->bsec && part == -1))) {
738	if (ioctl(fd, DIOCGSLICEINFO, &ds) == -1) {
739	    warn("ioctl (GSLICEINFO)");
740	    errx(1, "%s: can't get slice info", fname);
741	}
742	if (slice >= ds.dss_nslices || !ds.dss_slices[slice].ds_size)
743	    errx(1, "%s: slice is unavailable", fname);
744	if (!oflag)
745	    bpb->hid = ds.dss_slices[slice].ds_offset;
746	if (!bpb->bsec && part == -1)
747	    bpb->bsec = ds.dss_slices[slice].ds_size;
748    }
749    if (((slice == -1 || part != -1) &&
750	 ((!oflag && part != -1) || !bpb->bsec)) ||
751	!bpb->bps || !bpb->spt || !bpb->hds) {
752	lp = &dl;
753	i = ioctl(fd, DIOCGDINFO, lp);
754	if (i == -1 && slice != -1 && part == -1) {
755	    e = errno;
756	    if (!(s = strdup(fname)))
757		err(1, NULL);
758	    s[s1 - fname] = 0;
759	    if ((fd1 = open(s, O_RDONLY)) != -1) {
760		i = ioctl(fd1, DIOCGDINFO, lp);
761		close(fd1);
762	    }
763	    free(s);
764	    errno = e;
765	}
766	if (i == -1)
767	    if (!dtype) {
768		warn("ioctl (GDINFO)");
769		errx(1, "%s: can't read disk label; "
770		     "disk type must be specified", fname);
771	    } else if (!(lp = getdiskbyname(dtype)))
772		errx(1, "%s: unknown disk type", dtype);
773	if (slice == -1 || part != -1) {
774	    if (part == -1)
775		part = RAW_PART;
776	    if (part >= lp->d_npartitions ||
777		!lp->d_partitions[part].p_size)
778		errx(1, "%s: partition is unavailable", fname);
779	    if (!oflag && part != -1)
780		bpb->hid += lp->d_partitions[part].p_offset;
781	    if (!bpb->bsec)
782		bpb->bsec = lp->d_partitions[part].p_size;
783	}
784	if (!bpb->bps)
785	    bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
786	if (!bpb->spt)
787	    bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
788	if (!bpb->hds)
789	    bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
790    }
791}
792
793/*
794 * Print out BPB values.
795 */
796static void
797print_bpb(struct bpb *bpb)
798{
799    printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
800	   bpb->nft);
801    if (bpb->rde)
802	printf(" rde=%u", bpb->rde);
803    if (bpb->sec)
804	printf(" sec=%u", bpb->sec);
805    printf(" mid=0x%x", bpb->mid);
806    if (bpb->spf)
807	printf(" spf=%u", bpb->spf);
808    printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
809    if (bpb->bsec)
810	printf(" bsec=%u", bpb->bsec);
811    if (!bpb->spf) {
812	printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
813	printf(" infs=");
814	printf(bpb->infs == MAXU16 ? "0x%x" : "%u", bpb->infs);
815	printf(" bkbs=");
816	printf(bpb->bkbs == MAXU16 ? "0x%x" : "%u", bpb->bkbs);
817    }
818    printf("\n");
819}
820
821/*
822 * Check a disk geometry value.
823 */
824static u_int
825ckgeom(const char *fname, u_int val, const char *msg)
826{
827    if (!val)
828	errx(1, "%s: no default %s", fname, msg);
829    if (val > MAXU16)
830	errx(1, "%s: illegal %s", fname, msg);
831    return val;
832}
833
834/*
835 * Convert and check a numeric option argument.
836 */
837static u_int
838argtou(const char *arg, u_int lo, u_int hi, const char *msg)
839{
840    char *s;
841    u_long x;
842
843    errno = 0;
844    x = strtoul(arg, &s, 0);
845    if (errno || !*arg || *s || x < lo || x > hi)
846	errx(1, "%s: bad %s", arg, msg);
847    return x;
848}
849
850/*
851 * Check a volume label.
852 */
853static int
854oklabel(const char *src)
855{
856    int c, i;
857
858    for (i = 0; i <= 11; i++) {
859	c = (u_char)*src++;
860	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
861	    break;
862    }
863    return i && !c;
864}
865
866/*
867 * Make a volume label.
868 */
869static void
870mklabel(u_int8_t *dest, const char *src)
871{
872    int c, i;
873
874    for (i = 0; i < 11; i++) {
875	c = *src ? toupper(*src++) : ' ';
876	*dest++ = !i && c == '\xe5' ? 5 : c;
877    }
878}
879
880/*
881 * Copy string, padding with spaces.
882 */
883static void
884setstr(u_int8_t *dest, const char *src, size_t len)
885{
886    while (len--)
887	*dest++ = *src ? *src++ : ' ';
888}
889
890/*
891 * Print usage message.
892 */
893static void
894usage(void)
895{
896    fprintf(stderr,
897	    "usage: newfs_msdos [ -options ] special [disktype]\n");
898    fprintf(stderr, "where the options are:\n");
899    fprintf(stderr, "\t-N don't create file system: "
900	    "just print out parameters\n");
901    fprintf(stderr, "\t-B get bootstrap from file\n");
902    fprintf(stderr, "\t-F FAT type (12, 16, or 32)\n");
903    fprintf(stderr, "\t-I volume ID\n");
904    fprintf(stderr, "\t-L volume label\n");
905    fprintf(stderr, "\t-O OEM string\n");
906    fprintf(stderr, "\t-S bytes/sector\n");
907    fprintf(stderr, "\t-a sectors/FAT\n");
908    fprintf(stderr, "\t-b block size\n");
909    fprintf(stderr, "\t-c sectors/cluster\n");
910    fprintf(stderr, "\t-e root directory entries\n");
911    fprintf(stderr, "\t-f standard format\n");
912    fprintf(stderr, "\t-h drive heads\n");
913    fprintf(stderr, "\t-i file system info sector\n");
914    fprintf(stderr, "\t-k backup boot sector\n");
915    fprintf(stderr, "\t-m media descriptor\n");
916    fprintf(stderr, "\t-n number of FATs\n");
917    fprintf(stderr, "\t-o hidden sectors\n");
918    fprintf(stderr, "\t-r reserved sectors\n");
919    fprintf(stderr, "\t-s file system size (sectors)\n");
920    fprintf(stderr, "\t-u sectors/track\n");
921    exit(1);
922}
923