summaryrefslogtreecommitdiffstats
blob: d7047e2c47e485c14b9902657ced1f16ce7548eb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
/*
 * Copyright (c) 1998 Robert Nordier
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef lint
static const char rcsid[] =
        "$FreeBSD: src/sbin/newfs_msdos/newfs_msdos.c,v 1.33 2009/04/11 14:56:29 ed Exp $";
#endif /* not lint */

#include <sys/param.h>

#ifndef ANDROID
#include <sys/fdcio.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/mount.h>
#else
#include <stdarg.h>
#include <linux/fs.h>
#include <linux/hdreg.h>
#endif

#include <sys/stat.h>
#include <sys/time.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#define MAXU16   0xffff     /* maximum unsigned 16-bit quantity */
#define BPN      4          /* bits per nibble */
#define NPB      2          /* nibbles per byte */

#define DOSMAGIC  0xaa55    /* DOS magic number */
#define MINBPS    512       /* minimum bytes per sector */
#define MAXSPC    128       /* maximum sectors per cluster */
#define MAXNFT    16        /* maximum number of FATs */
#define DEFBLK    4096      /* default block size */
#define DEFBLK16  2048      /* default block size FAT16 */
#define DEFRDE    512       /* default root directory entries */
#define RESFTE    2         /* reserved FAT entries */
#define MINCLS12  1         /* minimum FAT12 clusters */
#define MINCLS16  0x1000    /* minimum FAT16 clusters */
#define MINCLS32  2         /* minimum FAT32 clusters */
#define MAXCLS12  0xfed     /* maximum FAT12 clusters */
#define MAXCLS16  0xfff5    /* maximum FAT16 clusters */
#define MAXCLS32  0xffffff5 /* maximum FAT32 clusters */

#define mincls(fat)  ((fat) == 12 ? MINCLS12 :    \
                      (fat) == 16 ? MINCLS16 :    \
                                        MINCLS32)

#define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :    \
                      (fat) == 16 ? MAXCLS16 :    \
                                        MAXCLS32)

#define mk1(p, x)                           \
    (p) = (u_int8_t)(x)

#define mk2(p, x)                           \
    (p)[0] = (u_int8_t)(x),                 \
    (p)[1] = (u_int8_t)((x) >> 010)

#define mk4(p, x)                           \
    (p)[0] = (u_int8_t)(x),                 \
    (p)[1] = (u_int8_t)((x) >> 010),        \
    (p)[2] = (u_int8_t)((x) >> 020),        \
    (p)[3] = (u_int8_t)((x) >> 030)

#define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
#define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
#define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
#define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)

struct bs {
    u_int8_t jmp[3];        /* bootstrap entry point */
    u_int8_t oem[8];        /* OEM name and version */
};

struct bsbpb {
    u_int8_t bps[2];    /* bytes per sector */
    u_int8_t spc;       /* sectors per cluster */
    u_int8_t res[2];    /* reserved sectors */
    u_int8_t nft;       /* number of FATs */
    u_int8_t rde[2];    /* root directory entries */
    u_int8_t sec[2];    /* total sectors */
    u_int8_t mid;       /* media descriptor */
    u_int8_t spf[2];    /* sectors per FAT */
    u_int8_t spt[2];    /* sectors per track */
    u_int8_t hds[2];    /* drive heads */
    u_int8_t hid[4];    /* hidden sectors */
    u_int8_t bsec[4];   /* big total sectors */
};

struct bsxbpb {
    u_int8_t bspf[4];       /* big sectors per FAT */
    u_int8_t xflg[2];       /* FAT control flags */
    u_int8_t vers[2];       /* file system version */
    u_int8_t rdcl[4];       /* root directory start cluster */
    u_int8_t infs[2];       /* file system info sector */
    u_int8_t bkbs[2];       /* backup boot sector */
    u_int8_t rsvd[12];      /* reserved */
};

struct bsx {
    u_int8_t drv;           /* drive number */
    u_int8_t rsvd;          /* reserved */
    u_int8_t sig;           /* extended boot signature */
    u_int8_t volid[4];      /* volume ID number */
    u_int8_t label[11];     /* volume label */
    u_int8_t type[8];       /* file system type */
};

struct de {
    u_int8_t namext[11];    /* name and extension */
    u_int8_t attr;          /* attributes */
    u_int8_t rsvd[10];      /* reserved */
    u_int8_t time[2];       /* creation time */
    u_int8_t date[2];       /* creation date */
    u_int8_t clus[2];       /* starting cluster */
    u_int8_t size[4];       /* size */
};

struct bpb {
    u_int bps;          /* bytes per sector */
    u_int spc;          /* sectors per cluster */
    u_int res;          /* reserved sectors */
    u_int nft;          /* number of FATs */
    u_int rde;          /* root directory entries */
    u_int sec;          /* total sectors */
    u_int mid;          /* media descriptor */
    u_int spf;          /* sectors per FAT */
    u_int spt;          /* sectors per track */
    u_int hds;          /* drive heads */
    u_int hid;          /* hidden sectors */
    u_int bsec;         /* big total sectors */
    u_int bspf;         /* big sectors per FAT */
    u_int rdcl;         /* root directory start cluster */
    u_int infs;         /* file system info sector */
    u_int bkbs;         /* backup boot sector */
};

#define BPBGAP 0, 0, 0, 0, 0, 0

static struct {
    const char *name;
    struct bpb bpb;
} const stdfmt[] = {
    {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
    {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
    {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
    {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
    {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
    {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
    {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
    {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
    {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
    {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
};

static const u_int8_t bootcode[] = {
    0xfa,               /* cli             */
    0x31, 0xc0,         /* xor    ax,ax    */
    0x8e, 0xd0,         /* mov    ss,ax    */
    0xbc, 0x00, 0x7c,   /* mov    sp,7c00h */
    0xfb,               /* sti             */
    0x8e, 0xd8,         /* mov    ds,ax    */
    0xe8, 0x00, 0x00,   /* call   $ + 3    */
    0x5e,               /* pop    si       */
    0x83, 0xc6, 0x19,   /* add    si,+19h  */
    0xbb, 0x07, 0x00,   /* mov    bx,0007h */
    0xfc,               /* cld             */
    0xac,               /* lodsb           */
    0x84, 0xc0,         /* test   al,al    */
    0x74, 0x06,         /* jz     $ + 8    */
    0xb4, 0x0e,         /* mov    ah,0eh   */
    0xcd, 0x10,         /* int    10h      */
    0xeb, 0xf5,         /* jmp    $ - 9    */
    0x30, 0xe4,         /* xor    ah,ah    */
    0xcd, 0x16,         /* int    16h      */
    0xcd, 0x19,         /* int    19h      */
    0x0d, 0x0a,
    'N', 'o', 'n', '-', 's', 'y', 's', 't',
    'e', 'm', ' ', 'd', 'i', 's', 'k',
    0x0d, 0x0a,
    'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
    'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
    ' ', 'r', 'e', 'b', 'o', 'o', 't',
    0x0d, 0x0a,
    0
};

static void check_mounted(const char *, mode_t);
static void getstdfmt(const char *, struct bpb *);
static void getdiskinfo(int, const char *, const char *, int, struct bpb *);
static void print_bpb(struct bpb *);
static u_int ckgeom(const char *, u_int, const char *);
static u_int argtou(const char *, u_int, u_int, const char *);
static off_t argtooff(const char *, const char *);
static int oklabel(const char *);
static void mklabel(u_int8_t *, const char *);
static void setstr(u_int8_t *, const char *, size_t);
static void usage(void);

/*
 * Construct a FAT12, FAT16, or FAT32 file system.
 */
int newfs_msdos_main(int argc, char *argv[])
{
    static const char opts[] = "@:NAB:C:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
    const char *opt_B = NULL, *opt_L = NULL, *opt_O = NULL, *opt_f = NULL;
    u_int opt_F = 0, opt_I = 0, opt_S = 0, opt_a = 0, opt_b = 0, opt_c = 0;
    u_int opt_e = 0, opt_h = 0, opt_i = 0, opt_k = 0, opt_m = 0, opt_n = 0;
    u_int opt_o = 0, opt_r = 0, opt_s = 0, opt_u = 0;
    u_int opt_A = 0;
    int opt_N = 0;
    int Iflag = 0, mflag = 0, oflag = 0;
    char buf[MAXPATHLEN];
    struct stat sb;
    struct timeval tv;
    struct bpb bpb;
    struct tm *tm;
    struct bs *bs;
    struct bsbpb *bsbpb;
    struct bsxbpb *bsxbpb;
    struct bsx *bsx;
    struct de *de;
    u_int8_t *img;
    const char *fname, *dtype, *bname;
    ssize_t n;
    time_t now;
    u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
    u_int extra_res, alignment=0, set_res, set_spf, set_spc, tempx, attempts=0;
    int ch, fd, fd1;
    off_t opt_create = 0, opt_ofs = 0;

    while ((ch = getopt(argc, argv, opts)) != -1)
        switch (ch) {
        case '@':
            opt_ofs = argtooff(optarg, "offset");
            break;
        case 'N':
            opt_N = 1;
            break;
        case 'A':
            opt_A = 1;
            break;
        case 'B':
            opt_B = optarg;
            break;
        case 'C':
            opt_create = argtooff(optarg, "create size");
            break;
        case 'F':
            if (strcmp(optarg, "12") &&  strcmp(optarg, "16") && strcmp(optarg, "32"))
                errx(1, "%s: bad FAT type", optarg);
            opt_F = atoi(optarg);
            break;
        case 'I':
            opt_I = argto4(optarg, 0, "volume ID");
            Iflag = 1;
            break;
        case 'L':
            if (!oklabel(optarg))
                errx(1, "%s: bad volume label", optarg);
            opt_L = optarg;
            break;
        case 'O':
            if (strlen(optarg) > 8)
                errx(1, "%s: bad OEM string", optarg);
            opt_O = optarg;
            break;
        case 'S':
            opt_S = argto2(optarg, 1, "bytes/sector");
            break;
        case 'a':
            opt_a = argto4(optarg, 1, "sectors/FAT");
            break;
        case 'b':
            opt_b = argtox(optarg, 1, "block size");
            opt_c = 0;
            break;
        case 'c':
            opt_c = argto1(optarg, 1, "sectors/cluster");
            opt_b = 0;
            break;
        case 'e':
            opt_e = argto2(optarg, 1, "directory entries");
            break;
        case 'f':
            opt_f = optarg;
            break;
        case 'h':
            opt_h = argto2(optarg, 1, "drive heads");
            break;
        case 'i':
            opt_i = argto2(optarg, 1, "info sector");
            break;
        case 'k':
            opt_k = argto2(optarg, 1, "backup sector");
            break;
        case 'm':
            opt_m = argto1(optarg, 0, "media descriptor");
            mflag = 1;
            break;
        case 'n':
            opt_n = argto1(optarg, 1, "number of FATs");
            break;
        case 'o':
            opt_o = argto4(optarg, 0, "hidden sectors");
            oflag = 1;
            break;
        case 'r':
            opt_r = argto2(optarg, 1, "reserved sectors");
            break;
        case 's':
            opt_s = argto4(optarg, 1, "file system size");
            break;
        case 'u':
            opt_u = argto2(optarg, 1, "sectors/track");
            break;
        default:
            usage();
        }
    argc -= optind;
    argv += optind;
    if (argc < 1 || argc > 2)
        usage();
    fname = *argv++;
    if (!opt_create && !strchr(fname, '/')) {
        snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
        if (!(fname = strdup(buf)))
            err(1, "%s", buf);
    }
    dtype = *argv;
    if (opt_A) {
        if (opt_r)
            errx(1, "align (-A) is incompatible with -r");
        if (opt_N)
            errx(1, "align (-A) is incompatible with -N");
    }
    if (opt_create) {
        if (opt_N)
            errx(1, "create (-C) is incompatible with -N");
        fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
        if (fd == -1)
            errx(1, "failed to create %s", fname);
        if (ftruncate(fd, opt_create))
            errx(1, "failed to initialize %jd bytes", (intmax_t)opt_create);
    } else if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1)
        err(1, "%s", fname);
    if (fstat(fd, &sb))
        err(1, "%s", fname);
    if (opt_create) {
        if (!S_ISREG(sb.st_mode))
            warnx("warning, %s is not a regular file", fname);
    } else {
        if (!S_ISCHR(sb.st_mode))
            warnx("warning, %s is not a character device", fname);
    }
    if (!opt_N)
        check_mounted(fname, sb.st_mode);
    if (opt_ofs && opt_ofs != lseek(fd, opt_ofs, SEEK_SET))
        errx(1, "cannot seek to %jd", (intmax_t)opt_ofs);
    memset(&bpb, 0, sizeof(bpb));
    if (opt_f) {
        getstdfmt(opt_f, &bpb);
        bpb.bsec = bpb.sec;
        bpb.sec = 0;
        bpb.bspf = bpb.spf;
        bpb.spf = 0;
    }
    if (opt_h)
        bpb.hds = opt_h;
    if (opt_u)
        bpb.spt = opt_u;
    if (opt_S)
        bpb.bps = opt_S;
    if (opt_s)
        bpb.bsec = opt_s;
    if (oflag)
        bpb.hid = opt_o;
    if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag))) {
        off_t delta;
        getdiskinfo(fd, fname, dtype, oflag, &bpb);
        if (opt_s) {
            bpb.bsec = opt_s;
        }
        bpb.bsec -= (opt_ofs / bpb.bps);
        delta = bpb.bsec % bpb.spt;
        if (delta != 0) {
            warnx("trim %d sectors from %d to adjust to a multiple of %d",
                  (int)delta, bpb.bsec, bpb.spt);
            bpb.bsec -= delta;
        }
        if (bpb.spc == 0) {    /* set defaults */
            if (bpb.bsec <= 6000)    /* about 3MB -> 512 bytes */
                bpb.spc = 1;
            else if (bpb.bsec <= (1<<17)) /* 64M -> 4k */
                bpb.spc = 8;
            else if (bpb.bsec <= (1<<19)) /* 256M -> 8k */
                bpb.spc = 16;
            else if (bpb.bsec <= (1<<22)) /* 2G -> 16k, some versions of windows
                                         require a minimum of 65527 clusters */
                bpb.spc = 32;
            else
                bpb.spc = 64;        /* otherwise 32k */
        }
    }
    if (!powerof2(bpb.bps))
        errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
    if (bpb.bps < MINBPS)
        errx(1, "bytes/sector (%u) is too small; minimum is %u",
             bpb.bps, MINBPS);
    if (!(fat = opt_F)) {
        if (opt_f)
            fat = 12;
        else if (!opt_e && (opt_i || opt_k))
            fat = 32;
    }
    if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
        errx(1, "-%c is not a legal FAT%s option",
             fat == 32 ? 'e' : opt_i ? 'i' : 'k',
                     fat == 32 ? "32" : "12/16");
    if (opt_f && fat == 32)
        bpb.rde = 0;
    if (opt_b) {
        if (!powerof2(opt_b))
            errx(1, "block size (%u) is not a power of 2", opt_b);
        if (opt_b < bpb.bps)
            errx(1, "block size (%u) is too small; minimum is %u",
                 opt_b, bpb.bps);
        if (opt_b > bpb.bps * MAXSPC)
            errx(1, "block size (%u) is too large; maximum is %u", opt_b, bpb.bps * MAXSPC);
        bpb.spc = opt_b / bpb.bps;
    }
    if (opt_c) {
        if (!powerof2(opt_c))
            errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
        bpb.spc = opt_c;
    }
    if (opt_r)
        bpb.res = opt_r;
    if (opt_n) {
        if (opt_n > MAXNFT)
            errx(1, "number of FATs (%u) is too large; maximum is %u", opt_n, MAXNFT);
        bpb.nft = opt_n;
    }
    if (opt_e)
        bpb.rde = opt_e;
    if (mflag) {
        if (opt_m < 0xf0)
            errx(1, "illegal media descriptor (%#x)", opt_m);
        bpb.mid = opt_m;
    }
    if (opt_a)
        bpb.bspf = opt_a;
    if (opt_i)
        bpb.infs = opt_i;
    if (opt_k)
        bpb.bkbs = opt_k;
    bss = 1;
    bname = NULL;
    fd1 = -1;
    if (opt_B) {
        bname = opt_B;
        if (!strchr(bname, '/')) {
            snprintf(buf, sizeof(buf), "/boot/%s", bname);
            if (!(bname = strdup(buf)))
                err(1, "%s", buf);
        }
        if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
            err(1, "%s", bname);
        if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
                sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
            errx(1, "%s: inappropriate file type or format", bname);
        bss = sb.st_size / bpb.bps;
    }
    if (!bpb.nft)
        bpb.nft = 2;
    if (!fat) {
        if (bpb.bsec < (bpb.res ? bpb.res : bss) +
                howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
                        ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
                        bpb.nft +
                        howmany(bpb.rde ? bpb.rde : DEFRDE,
                                bpb.bps / sizeof(struct de)) +
                                (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
                                (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
            fat = 12;
        else if (bpb.rde || bpb.bsec <
                (bpb.res ? bpb.res : bss) +
                howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
                howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
                (MAXCLS16 + 1) *
                (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
            fat = 16;
        else
            fat = 32;
    }
    x = bss;
    if (fat == 32) {
        if (!bpb.infs) {
            if (x == MAXU16 || x == bpb.bkbs)
                errx(1, "no room for info sector");
            bpb.infs = x;
        }
        if (bpb.infs != MAXU16 && x <= bpb.infs)
            x = bpb.infs + 1;
        if (!bpb.bkbs) {
            if (x == MAXU16)
                errx(1, "no room for backup sector");
            bpb.bkbs = x;
        } else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
            errx(1, "backup sector would overwrite info sector");
        if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
            x = bpb.bkbs + 1;
    }

    extra_res = 0;
    set_res = !bpb.res;
    set_spf = !bpb.bspf;
    set_spc = !bpb.spc;
    tempx = x;
    /*
     * Attempt to align if opt_A is set. This is done by increasing the number
     * of reserved blocks. This can cause other factors to change, which can in
     * turn change the alignment. This should take at most 2 iterations, as
     * increasing the reserved amount may cause the FAT size to decrease by 1,
     * requiring another nft reserved blocks. If spc changes, it will
     * be half of its previous size, and thus will not throw off alignment.
     */
    do {
        x = tempx;
        if (set_res)
            bpb.res = (fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x) + extra_res;
        else if (bpb.res < x)
            errx(1, "too few reserved sectors");
        if (fat != 32 && !bpb.rde)
            bpb.rde = DEFRDE;
        rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
        if (set_spc)
            for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
                    bpb.spc < MAXSPC &&
                    bpb.res +
                    howmany((RESFTE + maxcls(fat)) * (fat / BPN),
                            bpb.bps * NPB) * bpb.nft +
                            rds +
                            (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
                    bpb.spc <<= 1);
        if (fat != 32 && bpb.bspf > MAXU16)
            errx(1, "too many sectors/FAT for FAT12/16");
        x1 = bpb.res + rds;
        x = bpb.bspf ? bpb.bspf : 1;
        if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
            errx(1, "meta data exceeds file system size");
        x1 += x * bpb.nft;
        x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
                (bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
        x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN), bpb.bps * NPB);
        if (set_spf) {
            if (!bpb.bspf) {
                bpb.bspf = x2;
            }
            x1 += (bpb.bspf - 1) * bpb.nft;
        }
        if(set_res) {
            /* attempt to align root directory */
            alignment = (bpb.res + bpb.bspf * bpb.nft) % bpb.spc;
            extra_res += bpb.spc - alignment;
        }
        attempts++;
    } while(opt_A && alignment != 0 && attempts < 2);
    if (alignment != 0)
        warnx("warning: Alignment failed.");

    cls = (bpb.bsec - x1) / bpb.spc;
    x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
    if (cls > x)
        cls = x;
    if (bpb.bspf < x2)
        warnx("warning: sectors/FAT limits file system to %u clusters", cls);
    if (cls < mincls(fat))
        errx(1, "%u clusters too few clusters for FAT%u, need %u", cls, fat, mincls(fat));
    if (cls > maxcls(fat)) {
        cls = maxcls(fat);
        bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
        warnx("warning: FAT type limits file system to %u sectors", bpb.bsec);
    }
    printf("%s: %u sector%s in %u FAT%u cluster%s (%u bytes/cluster)\n",
           fname, cls * bpb.spc, cls * bpb.spc == 1 ? "" : "s", cls, fat,
           cls == 1 ? "" : "s", bpb.bps * bpb.spc);
    if (!bpb.mid)
        bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
    if (fat == 32)
        bpb.rdcl = RESFTE;
    if (bpb.hid + bpb.bsec <= MAXU16) {
        bpb.sec = bpb.bsec;
        bpb.bsec = 0;
    }
    if (fat != 32) {
        bpb.spf = bpb.bspf;
        bpb.bspf = 0;
    }
    print_bpb(&bpb);
    if (!opt_N) {
        gettimeofday(&tv, NULL);
        now = tv.tv_sec;
        tm = localtime(&now);
        if (!(img = malloc(bpb.bps)))
            err(1, "%u", bpb.bps);
        dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
        for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
            x = lsn;
            if (opt_B && fat == 32 && bpb.bkbs != MAXU16 && bss <= bpb.bkbs && x >= bpb.bkbs) {
                x -= bpb.bkbs;
                if (!x && lseek(fd1, opt_ofs, SEEK_SET))
                    err(1, "%s", bname);
            }
            if (opt_B && x < bss) {
                if ((n = read(fd1, img, bpb.bps)) == -1)
                    err(1, "%s", bname);
                if ((unsigned)n != bpb.bps)
                    errx(1, "%s: can't read sector %u", bname, x);
            } else
                memset(img, 0, bpb.bps);
            if (!lsn || (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
                x1 = sizeof(struct bs);
                bsbpb = (struct bsbpb *)(img + x1);
                mk2(bsbpb->bps, bpb.bps);
                mk1(bsbpb->spc, bpb.spc);
                mk2(bsbpb->res, bpb.res);
                mk1(bsbpb->nft, bpb.nft);
                mk2(bsbpb->rde, bpb.rde);
                mk2(bsbpb->sec, bpb.sec);
                mk1(bsbpb->mid, bpb.mid);
                mk2(bsbpb->spf, bpb.spf);
                mk2(bsbpb->spt, bpb.spt);
                mk2(bsbpb->hds, bpb.hds);
                mk4(bsbpb->hid, bpb.hid);
                mk4(bsbpb->bsec, bpb.bsec);
                x1 += sizeof(struct bsbpb);
                if (fat == 32) {
                    bsxbpb = (struct bsxbpb *)(img + x1);
                    mk4(bsxbpb->bspf, bpb.bspf);
                    mk2(bsxbpb->xflg, 0);
                    mk2(bsxbpb->vers, 0);
                    mk4(bsxbpb->rdcl, bpb.rdcl);
                    mk2(bsxbpb->infs, bpb.infs);
                    mk2(bsxbpb->bkbs, bpb.bkbs);
                    x1 += sizeof(struct bsxbpb);
                }
                bsx = (struct bsx *)(img + x1);
                mk1(bsx->sig, 0x29);
                if (Iflag)
                    x = opt_I;
                else
                    x = (((u_int)(1 + tm->tm_mon) << 8 |
                            (u_int)tm->tm_mday) +
                            ((u_int)tm->tm_sec << 8 |
                                    (u_int)(tv.tv_usec / 10))) << 16 |
                                    ((u_int)(1900 + tm->tm_year) +
                                            ((u_int)tm->tm_hour << 8 |
                                                    (u_int)tm->tm_min));
                mk4(bsx->volid, x);
                mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
                snprintf(buf, sizeof(buf), "FAT%u", fat);
                setstr(bsx->type, buf, sizeof(bsx->type));
                if (!opt_B) {
                    x1 += sizeof(struct bsx);
                    bs = (struct bs *)img;
                    mk1(bs->jmp[0], 0xeb);
                    mk1(bs->jmp[1], x1 - 2);
                    mk1(bs->jmp[2], 0x90);
                    setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
                            sizeof(bs->oem));
                    memcpy(img + x1, bootcode, sizeof(bootcode));
                    mk2(img + MINBPS - 2, DOSMAGIC);
                }
            } else if (fat == 32 && bpb.infs != MAXU16 &&
                    (lsn == bpb.infs || (bpb.bkbs != MAXU16 &&
                                    lsn == bpb.bkbs + bpb.infs))) {
                mk4(img, 0x41615252);
                mk4(img + MINBPS - 28, 0x61417272);
                mk4(img + MINBPS - 24, 0xffffffff);
                mk4(img + MINBPS - 20, bpb.rdcl);
                mk2(img + MINBPS - 2, DOSMAGIC);
            } else if (lsn >= bpb.res && lsn < dir &&
                    !((lsn - bpb.res) % (bpb.spf ? bpb.spf : bpb.bspf))) {
                mk1(img[0], bpb.mid);
                for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
                    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
            } else if (lsn == dir && opt_L) {
                de = (struct de *)img;
                mklabel(de->namext, opt_L);
                mk1(de->attr, 050);
                x = (u_int)tm->tm_hour << 11 |
                        (u_int)tm->tm_min << 5 |
                        (u_int)tm->tm_sec >> 1;
                mk2(de->time, x);
                x = (u_int)(tm->tm_year - 80) << 9 |
                        (u_int)(tm->tm_mon + 1) << 5 |
                        (u_int)tm->tm_mday;
                mk2(de->date, x);
            }
            if ((n = write(fd, img, bpb.bps)) == -1)
                err(1, "%s", fname);
            if ((unsigned)n != bpb.bps) {
                errx(1, "%s: can't write sector %u", fname, lsn);
                exit(1);
            }
        }
        free(img);
    }
    return 0;
}

/*
 * Exit with error if file system is mounted.
 */
static void check_mounted(const char *fname, mode_t mode)
{
#ifdef ANDROID
    warnx("Skipping mount checks");
#else
    struct statfs *mp;
    const char *s1, *s2;
    size_t len;
    int n, r;

    if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
        err(1, "getmntinfo");
    len = strlen(_PATH_DEV);
    s1 = fname;
    if (!strncmp(s1, _PATH_DEV, len))
        s1 += len;
    r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
    for (; n--; mp++) {
        s2 = mp->f_mntfromname;
        if (!strncmp(s2, _PATH_DEV, len))
            s2 += len;
        if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) || !strcmp(s1, s2))
            errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
    }
#endif
}

/*
 * Get a standard format.
 */
static void getstdfmt(const char *fmt, struct bpb *bpb)
{
    u_int x, i;

    x = sizeof(stdfmt) / sizeof(stdfmt[0]);
    for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
    if (i == x)
        errx(1, "%s: unknown standard format", fmt);
    *bpb = stdfmt[i].bpb;
}

/*
 * Get disk slice, partition, and geometry information.
 */

#ifdef ANDROID
static void getdiskinfo(int fd, const char *fname, const char *dtype,
                        __unused int oflag,struct bpb *bpb)
{
    struct hd_geometry geom;
    u_long block_size;

    if (ioctl(fd, BLKSSZGET, &bpb->bps)) {
        fprintf(stderr, "Error getting bytes / sector (%s)\n", strerror(errno));
        exit(1);
    }

    ckgeom(fname, bpb->bps, "bytes/sector");

    if (ioctl(fd, BLKGETSIZE, &block_size)) {
        fprintf(stderr, "Error getting blocksize (%s)\n", strerror(errno));
        exit(1);
    }

    if (block_size > UINT32_MAX) {
        fprintf(stderr, "Error blocksize too large: %lu\n", block_size);
        exit(1);
    }

    bpb->bsec = (u_int)block_size;

    if (ioctl(fd, HDIO_GETGEO, &geom)) {
        fprintf(stderr, "Error getting gemoetry (%s) - trying sane values\n", strerror(errno));
        geom.heads = 64;
        geom.sectors = 63;
    }

    if (!geom.heads) {
        printf("Bogus heads from kernel - setting sane value\n");
        geom.heads = 64;
    }

    if (!geom.sectors) {
        printf("Bogus sectors from kernel - setting sane value\n");
        geom.sectors = 63;
    }

    bpb->spt = geom.sectors;
    ckgeom(fname, bpb->spt, "sectors/track");

    bpb->hds = geom.heads;
    ckgeom(fname, bpb->hds, "drive heads");
}

#else

static void getdiskinfo(int fd, const char *fname, const char *dtype,
                        __unused int oflag, struct bpb *bpb)
{
    struct disklabel *lp, dlp;
    struct fd_type type;
    off_t ms, hs = 0;

    lp = NULL;

    /* If the user specified a disk type, try to use that */
    if (dtype != NULL) {
        lp = getdiskbyname(dtype);
    }

    /* Maybe it's a floppy drive */
    if (lp == NULL) {
        if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
            struct stat st;

            if (fstat(fd, &st))
                err(1, "Cannot get disk size");
            /* create a fake geometry for a file image */
            ms = st.st_size;
            dlp.d_secsize = 512;
            dlp.d_nsectors = 63;
            dlp.d_ntracks = 255;
            dlp.d_secperunit = ms / dlp.d_secsize;
            lp = &dlp;
        } else if (ioctl(fd, FD_GTYPE, &type) != -1) {
            dlp.d_secsize = 128 << type.secsize;
            dlp.d_nsectors = type.sectrac;
            dlp.d_ntracks = type.heads;
            dlp.d_secperunit = ms / dlp.d_secsize;
            lp = &dlp;
        }
    }

    /* Maybe it's a fixed drive */
    if (lp == NULL) {
        if (ioctl(fd, DIOCGDINFO, &dlp) == -1) {
            if (bpb->bps == 0 && ioctl(fd, DIOCGSECTORSIZE, &dlp.d_secsize) == -1)
                errx(1, "Cannot get sector size, %s", strerror(errno));

            /* XXX Should we use bpb->bps if it's set? */
            dlp.d_secperunit = ms / dlp.d_secsize;

            if (bpb->spt == 0 && ioctl(fd, DIOCGFWSECTORS, &dlp.d_nsectors) == -1) {
                warnx("Cannot get number of sectors per track, %s", strerror(errno));
                dlp.d_nsectors = 63;
            }
            if (bpb->hds == 0 && ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
                warnx("Cannot get number of heads, %s", strerror(errno));
                if (dlp.d_secperunit <= 63*1*1024)
                    dlp.d_ntracks = 1;
                else if (dlp.d_secperunit <= 63*16*1024)
                    dlp.d_ntracks = 16;
                else
                    dlp.d_ntracks = 255;
            }
        }

        hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
        lp = &dlp;
    }

    if (bpb->bps == 0)
        bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
    if (bpb->spt == 0)
        bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
    if (bpb->hds == 0)
        bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
    if (bpb->bsec == 0)
        bpb->bsec = lp->d_secperunit;
    if (bpb->hid == 0)
        bpb->hid = hs;
}
#endif

/*
 * Print out BPB values.
 */
static void print_bpb(struct bpb *bpb)
{
    printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
           bpb->nft);
    if (bpb->rde)
        printf(" rde=%u", bpb->rde);
    if (bpb->sec)
        printf(" sec=%u", bpb->sec);
    printf(" mid=%#x", bpb->mid);
    if (bpb->spf)
        printf(" spf=%u", bpb->spf);
    printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
    if (bpb->bsec)
        printf(" bsec=%u", bpb->bsec);
    if (!bpb->spf) {
        printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
        printf(" infs=");
        printf(bpb->infs == MAXU16 ? "%#x" : "%u", bpb->infs);
        printf(" bkbs=");
        printf(bpb->bkbs == MAXU16 ? "%#x" : "%u", bpb->bkbs);
    }
    printf("\n");
}

/*
 * Check a disk geometry value.
 */
static u_int ckgeom(const char *fname, u_int val, const char *msg)
{
    if (!val)
        errx(1, "%s: no default %s", fname, msg);
    if (val > MAXU16)
        errx(1, "%s: illegal %s %d", fname, msg, val);
    return val;
}

/*
 * Convert and check a numeric option argument.
 */
static u_int argtou(const char *arg, u_int lo, u_int hi, const char *msg)
{
    char *s;
    u_long x;

    errno = 0;
    x = strtoul(arg, &s, 0);
    if (errno || !*arg || *s || x < lo || x > hi)
        errx(1, "%s: bad %s", arg, msg);
    return x;
}

/*
 * Same for off_t, with optional skmgpP suffix
 */
static off_t argtooff(const char *arg, const char *msg)
{
    char *s;
    off_t x;

    x = strtoll(arg, &s, 0);
    /* allow at most one extra char */
    if (errno || x < 0 || (s[0] && s[1]) )
        errx(1, "%s: bad %s", arg, msg);
    if (*s) {    /* the extra char is the multiplier */
        switch (*s) {
            default:
                errx(1, "%s: bad %s", arg, msg);
                /* notreached */

            case 's':       /* sector */
            case 'S':
                x <<= 9;    /* times 512 */
                break;

            case 'k':       /* kilobyte */
            case 'K':
                x <<= 10;   /* times 1024 */
                break;

            case 'm':       /* megabyte */
            case 'M':
                x <<= 20;   /* times 1024*1024 */
                break;

            case 'g':       /* gigabyte */
            case 'G':
                x <<= 30;   /* times 1024*1024*1024 */
                break;

            case 'p':       /* partition start */
            case 'P':       /* partition start */
            case 'l':       /* partition length */
            case 'L':       /* partition length */
                errx(1, "%s: not supported yet %s", arg, msg);
                /* notreached */
        }
    }
    return x;
}

/*
 * Check a volume label.
 */
static int oklabel(const char *src)
{
    int c, i;

    for (i = 0; i <= 11; i++) {
        c = (u_char)*src++;
        if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
            break;
    }
    return i && !c;
}

/*
 * Make a volume label.
 */
static void mklabel(u_int8_t *dest, const char *src)
{
    int c, i;

    for (i = 0; i < 11; i++) {
        c = *src ? toupper(*src++) : ' ';
        *dest++ = !i && c == '\xe5' ? 5 : c;
    }
}

/*
 * Copy string, padding with spaces.
 */
static void setstr(u_int8_t *dest, const char *src, size_t len)
{
    while (len--)
        *dest++ = *src ? *src++ : ' ';
}

/*
 * Print usage message.
 */
static void usage(void)
{
    fprintf(stderr,
            "usage: newfs_msdos [ -options ] special [disktype]\n"
            "where the options are:\n"
            "\t-@ create file system at specified offset\n"
            "\t-A Attempt to cluster align root directory\n"
            "\t-B get bootstrap from file\n"
            "\t-C create image file with specified size\n"
            "\t-F FAT type (12, 16, or 32)\n"
            "\t-I volume ID\n"
            "\t-L volume label\n"
            "\t-N don't create file system: just print out parameters\n"
            "\t-O OEM string\n"
            "\t-S bytes/sector\n"
            "\t-a sectors/FAT\n"
            "\t-b block size\n"
            "\t-c sectors/cluster\n"
            "\t-e root directory entries\n"
            "\t-f standard format\n"
            "\t-h drive heads\n"
            "\t-i file system info sector\n"
            "\t-k backup boot sector\n"
            "\t-m media descriptor\n"
            "\t-n number of FATs\n"
            "\t-o hidden sectors\n"
            "\t-r reserved sectors\n"
            "\t-s file system size (sectors)\n"
            "\t-u sectors/track\n");
    exit(1);
}