1 /* vi: set sw=4 ts=4: */
3 * mkfs_vfat: utility to create FAT32 filesystem
4 * inspired by dosfstools
6 * Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
8 * Licensed under GPLv2, see file LICENSE in this source tree.
10 //config:config MKDOSFS
11 //config: bool "mkdosfs (6.8 kb)"
13 //config: select PLATFORM_LINUX
15 //config: Utility to create FAT32 filesystems.
17 //config:config MKFS_VFAT
18 //config: bool "mkfs.vfat (6.8 kb)"
20 //config: select PLATFORM_LINUX
22 //config: Alias to "mkdosfs".
24 // APPLET_ODDNAME:name main location suid_type help
25 //applet:IF_MKDOSFS( APPLET_ODDNAME(mkdosfs, mkfs_vfat, BB_DIR_SBIN, BB_SUID_DROP, mkfs_vfat))
26 //applet:IF_MKFS_VFAT(APPLET_ODDNAME(mkfs.vfat, mkfs_vfat, BB_DIR_SBIN, BB_SUID_DROP, mkfs_vfat))
28 //kbuild:lib-$(CONFIG_MKDOSFS) += mkfs_vfat.o
29 //kbuild:lib-$(CONFIG_MKFS_VFAT) += mkfs_vfat.o
31 //usage:#define mkfs_vfat_trivial_usage
32 //usage: "[-v] [-n LABEL] BLOCKDEV [KBYTES]"
33 /* Accepted but ignored:
34 "[-c] [-C] [-I] [-l bad-block-file] [-b backup-boot-sector] "
35 "[-m boot-msg-file] [-i volume-id] "
36 "[-s sectors-per-cluster] [-S logical-sector-size] [-f number-of-FATs] "
37 "[-h hidden-sectors] [-F fat-size] [-r root-dir-entries] [-R reserved-sectors] "
39 //usage:#define mkfs_vfat_full_usage "\n\n"
40 //usage: "Make a FAT32 filesystem\n"
41 /* //usage: "\n -c Check device for bad blocks" */
42 //usage: "\n -v Verbose"
43 /* //usage: "\n -I Allow to use entire disk device (e.g. /dev/hda)" */
44 //usage: "\n -n LBL Volume label"
48 #include <linux/hdreg.h> /* HDIO_GETGEO */
49 #include <linux/fd.h> /* FDGETPRM */
50 #include <sys/mount.h> /* BLKSSZGET */
51 #if !defined(BLKSSZGET)
52 # define BLKSSZGET _IO(0x12, 104)
54 //#include <linux/msdos_fs.h>
56 #define SECTOR_SIZE 512
58 #define SECTORS_PER_BLOCK (BLOCK_SIZE / SECTOR_SIZE)
60 // M$ says the high 4 bits of a FAT32 FAT entry are reserved
61 #define EOF_FAT32 0x0FFFFFF8
62 #define BAD_FAT32 0x0FFFFFF7
63 #define MAX_CLUST_32 0x0FFFFFF0
69 /* FAT32 filesystem looks like this:
70 * sector -nn...-1: "hidden" sectors, all sectors before this partition
71 * (-h hidden-sectors sets it. Useful only for boot loaders,
72 * they need to know _disk_ offset in order to be able to correctly
73 * address sectors relative to start of disk)
74 * sector 0: boot sector
75 * sector 1: info sector
76 * sector 2: set aside for boot code which didn't fit into sector 0
77 * ...(zero-filled sectors)...
78 * sector B: backup copy of sector 0 [B set by -b backup-boot-sector]
79 * sector B+1: backup copy of sector 1
80 * sector B+2: backup copy of sector 2
81 * ...(zero-filled sectors)...
82 * sector R: FAT#1 [R set by -R reserved-sectors]
84 * sector R+fat_size: FAT#2
86 * sector R+fat_size*2: cluster #2
88 * sector R+fat_size*2+clust_size: cluster #3
89 * ...(the rest is filled by clusters till the end)...
93 // Perhaps this should remain constant
94 info_sector_number = 1,
95 // TODO: make these cmdline options
96 // dont forget sanity check: backup_boot_sector + 3 <= reserved_sect
97 backup_boot_sector = 3,
101 // how many blocks we try to read while testing
102 #define TEST_BUFFER_BLOCKS 16
104 struct msdos_dir_entry {
105 char name[11]; /* 000 name and extension */
106 uint8_t attr; /* 00b attribute bits */
107 uint8_t lcase; /* 00c case for base and extension */
108 uint8_t ctime_cs; /* 00d creation time, centiseconds (0-199) */
109 uint16_t ctime; /* 00e creation time */
110 uint16_t cdate; /* 010 creation date */
111 uint16_t adate; /* 012 last access date */
112 uint16_t starthi; /* 014 high 16 bits of cluster in FAT32 */
113 uint16_t time; /* 016 time */
114 uint16_t date; /* 018 date */
115 uint16_t start; /* 01a first cluster */
116 uint32_t size; /* 01c file size in bytes */
119 /* Example of boot sector's beginning:
120 0000 eb 58 90 4d 53 57 49 4e 34 2e 31 00 02 08 26 00 |...MSWIN4.1...&.|
121 0010 02 00 00 00 00 f8 00 00 3f 00 ff 00 3f 00 00 00 |........?...?...|
122 0020 54 9b d0 00 0d 34 00 00 00 00 00 00 02 00 00 00 |T....4..........|
123 0030 01 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
124 0040 80 00 29 71 df 51 e0 4e 4f 20 4e 41 4d 45 20 20 |..)q.Q.NO NAME |
125 0050 20 20 46 41 54 33 32 20 20 20 33 c9 8e d1 bc f4 | FAT32 3.....|
127 struct msdos_volume_info { /* (offsets are relative to start of boot sector) */
128 uint8_t drive_number; /* 040 BIOS drive number */
129 uint8_t reserved; /* 041 unused */
130 uint8_t ext_boot_sign; /* 042 0x29 if fields below exist (DOS 3.3+) */
131 uint32_t volume_id32; /* 043 volume ID number */
132 char volume_label[11];/* 047 volume label */
133 char fs_type[8]; /* 052 typically "FATnn" */
134 } PACKED; /* 05a end. Total size 26 (0x1a) bytes */
136 struct msdos_boot_sector {
137 /* We use strcpy to fill both, and gcc-4.4.x complains if they are separate */
138 char boot_jump_and_sys_id[3+8]; /* 000 short or near jump instruction */
139 /*char system_id[8];*/ /* 003 name - can be used to special case partition manager volumes */
140 uint16_t bytes_per_sect; /* 00b bytes per logical sector */
141 uint8_t sect_per_clust; /* 00d sectors/cluster */
142 uint16_t reserved_sect; /* 00e reserved sectors (sector offset of 1st FAT relative to volume start) */
143 uint8_t fats; /* 010 number of FATs */
144 uint16_t dir_entries; /* 011 root directory entries */
145 uint16_t volume_size_sect; /* 013 volume size in sectors */
146 uint8_t media_byte; /* 015 media code */
147 uint16_t sect_per_fat; /* 016 sectors/FAT */
148 uint16_t sect_per_track; /* 018 sectors per track */
149 uint16_t heads; /* 01a number of heads */
150 uint32_t hidden; /* 01c hidden sectors (sector offset of volume within physical disk) */
151 uint32_t fat32_volume_size_sect; /* 020 volume size in sectors (if volume_size_sect == 0) */
152 uint32_t fat32_sect_per_fat; /* 024 sectors/FAT */
153 uint16_t fat32_flags; /* 028 bit 8: fat mirroring, low 4: active fat */
154 uint8_t fat32_version[2]; /* 02a major, minor filesystem version (I see 0,0) */
155 uint32_t fat32_root_cluster; /* 02c first cluster in root directory */
156 uint16_t fat32_info_sector; /* 030 filesystem info sector (usually 1) */
157 uint16_t fat32_backup_boot; /* 032 backup boot sector (usually 6) */
158 uint32_t reserved2[3]; /* 034 unused */
159 struct msdos_volume_info vi; /* 040 */
160 char boot_code[0x200 - 0x5a - 2]; /* 05a */
161 #define BOOT_SIGN 0xAA55
162 uint16_t boot_sign; /* 1fe */
165 #define FAT_FSINFO_SIG1 0x41615252
166 #define FAT_FSINFO_SIG2 0x61417272
167 struct fat32_fsinfo {
168 uint32_t signature1; /* 0x52,0x52,0x41,0x61, "RRaA" */
169 uint32_t reserved1[128 - 8];
170 uint32_t signature2; /* 0x72,0x72,0x61,0x41, "rrAa" */
171 uint32_t free_clusters; /* free cluster count. -1 if unknown */
172 uint32_t next_cluster; /* most recently allocated cluster */
173 uint32_t reserved2[3];
174 uint16_t reserved3; /* 1fc */
175 uint16_t boot_sign; /* 1fe */
179 char BUG1[sizeof(struct msdos_dir_entry ) == 0x20 ? 1 : -1];
180 char BUG2[sizeof(struct msdos_volume_info) == 0x1a ? 1 : -1];
181 char BUG3[sizeof(struct msdos_boot_sector) == 0x200 ? 1 : -1];
182 char BUG4[sizeof(struct fat32_fsinfo ) == 0x200 ? 1 : -1];
185 static const char boot_code[] ALIGN1 =
186 "\x0e" /* 05a: push cs */
187 "\x1f" /* 05b: pop ds */
188 "\xbe\x77\x7c" /* write_msg: mov si, offset message_txt */
189 "\xac" /* 05f: lodsb */
190 "\x22\xc0" /* 060: and al, al */
191 "\x74\x0b" /* 062: jz key_press */
192 "\x56" /* 064: push si */
193 "\xb4\x0e" /* 065: mov ah, 0eh */
194 "\xbb\x07\x00" /* 067: mov bx, 0007h */
195 "\xcd\x10" /* 06a: int 10h */
196 "\x5e" /* 06c: pop si */
197 "\xeb\xf0" /* 06d: jmp write_msg */
198 "\x32\xe4" /* key_press: xor ah, ah */
199 "\xcd\x16" /* 071: int 16h */
200 "\xcd\x19" /* 073: int 19h */
201 "\xeb\xfe" /* foo: jmp foo */
202 /* 077: message_txt: */
203 "This is not a bootable disk\r\n";
206 #define MARK_CLUSTER(cluster, value) \
207 ((uint32_t *)fat)[cluster] = SWAP_LE32(value)
209 void BUG_unsupported_field_size(void);
210 #define STORE_LE(field, value) \
212 if (sizeof(field) == 4) \
213 field = SWAP_LE32((uint32_t)(value)); \
214 else if (sizeof(field) == 2) \
215 field = SWAP_LE16((uint16_t)(value)); \
216 else if (sizeof(field) == 1) \
217 field = (uint8_t)(value); \
219 BUG_unsupported_field_size(); \
223 * mkdosfs 2.11 (12 Mar 2005)
224 * Usage: mkdosfs [-A] [-c] [-C] [-v] [-I] [-l bad-block-file]
225 * [-b backup-boot-sector]
226 * [-m boot-msg-file] [-n volume-name] [-i volume-id]
227 * [-s sectors-per-cluster] [-S logical-sector-size]
228 * [-f number-of-FATs]
229 * [-h hidden-sectors] [-F fat-size] [-r root-dir-entries]
230 * [-R reserved-sectors]
233 int mkfs_vfat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
234 int mkfs_vfat_main(int argc UNUSED_PARAM, char **argv)
237 const char *volume_label = "";
240 uoff_t volume_size_bytes;
241 uoff_t volume_size_sect;
242 uint32_t total_clust;
245 unsigned bytes_per_sect;
246 unsigned sect_per_fat;
248 uint16_t sect_per_track;
250 uint8_t sect_per_clust;
253 OPT_A = 1 << 0, // [IGNORED] atari format
254 OPT_b = 1 << 1, // [IGNORED] location of backup boot sector
255 OPT_c = 1 << 2, // [IGNORED] check filesystem
256 OPT_C = 1 << 3, // [IGNORED] create a new file
257 OPT_f = 1 << 4, // [IGNORED] number of FATs
258 OPT_F = 1 << 5, // [IGNORED, implied 32] choose FAT size
259 OPT_h = 1 << 6, // [IGNORED] number of hidden sectors
260 OPT_I = 1 << 7, // [IGNORED] don't bark at entire disk devices
261 OPT_i = 1 << 8, // [IGNORED] volume ID
262 OPT_l = 1 << 9, // [IGNORED] bad block filename
263 OPT_m = 1 << 10, // [IGNORED] message file
264 OPT_n = 1 << 11, // volume label
265 OPT_r = 1 << 12, // [IGNORED] root directory entries
266 OPT_R = 1 << 13, // [IGNORED] number of reserved sectors
267 OPT_s = 1 << 14, // [IGNORED] sectors per cluster
268 OPT_S = 1 << 15, // [IGNORED] sector size
269 OPT_v = 1 << 16, // verbose
272 opts = getopt32(argv, "^"
273 "Ab:cCf:F:h:Ii:l:m:n:r:R:s:S:v"
274 "\0" "-1", //:b+:f+:F+:h+:r+:R+:s+:S+:vv:c--l:l--c
275 NULL, NULL, NULL, NULL, NULL,
276 NULL, NULL, &volume_label, NULL, NULL, NULL, NULL);
280 device_name = argv[0];
281 // default volume ID = creation time
282 volume_id = time(NULL);
284 dev = xopen(device_name, O_RDWR);
285 xfstat(dev, &st, device_name);
288 // Get image size and sector size
290 bytes_per_sect = SECTOR_SIZE;
291 if (!S_ISBLK(st.st_mode)) {
292 if (!S_ISREG(st.st_mode)) {
294 bb_error_msg_and_die("image size must be specified");
296 // not a block device, skip bad sectors check
299 int min_bytes_per_sect;
302 // for true block devices we do check sanity
303 device_num = st.st_rdev & 0xff3f;
304 // do we allow to format the whole disk device?
305 if (!(opts & OPT_I) && (
306 device_num == 0x0300 || // hda, hdb
307 (device_num & 0xff0f) == 0x0800 || // sd
308 device_num == 0x0d00 || // xd
309 device_num == 0x1600 ) // hdc, hdd
311 bb_error_msg_and_die("will not try to make filesystem on full-disk device (use -I if wanted)");
312 // can't work on mounted filesystems
313 if (find_mount_point(device_name, 0))
314 bb_error_msg_and_die("can't format mounted filesystem");
316 // get true sector size
317 // (parameter must be int*, not long* or size_t*)
318 xioctl(dev, BLKSSZGET, &min_bytes_per_sect);
319 if (min_bytes_per_sect > SECTOR_SIZE) {
320 bytes_per_sect = min_bytes_per_sect;
321 bb_error_msg("for this device sector size is %u", min_bytes_per_sect);
324 volume_size_bytes = get_volume_size_in_bytes(dev, argv[1], 1024, /*extend:*/ 1);
325 volume_size_sect = volume_size_bytes / bytes_per_sect;
328 // Find out or guess media parameters
335 struct hd_geometry geometry;
336 // size (in sectors), sect (per track), head
337 struct floppy_struct param;
339 // N.B. whether to use HDIO_GETGEO or HDIO_REQ?
340 if (ioctl(dev, HDIO_GETGEO, &geometry) == 0
345 sect_per_track = geometry.sectors;
346 heads = geometry.heads;
349 /* For FAT32, try to do the same as M$'s format command
350 * (see http://www.win.tue.nl/~aeb/linux/fs/fat/fatgen103.pdf p. 20):
351 * fs size <= 260M: 0.5k clusters
352 * fs size <= 8G: 4k clusters
353 * fs size <= 16G: 8k clusters
354 * fs size > 16G: 16k clusters
357 if (volume_size_bytes >= 260*1024*1024) {
360 /* "error: integer overflow in expression" */
361 /* "error: right shift count >= width of type" */
362 if (sizeof(off_t) > 4) {
363 unsigned t = (volume_size_bytes >> 31 >> 1);
371 // floppy, loop, or regular file
372 int not_floppy = ioctl(dev, FDGETPRM, ¶m);
373 if (not_floppy == 0) {
375 sect_per_track = param.sect;
377 volume_size_sect = param.size;
378 volume_size_bytes = param.size * SECTOR_SIZE;
380 // setup the media descriptor byte
381 switch (volume_size_sect) {
382 case 2*360: // 5.25", 2, 9, 40 - 360K
385 case 2*720: // 3.5", 2, 9, 80 - 720K
386 case 2*1200: // 5.25", 2, 15, 80 - 1200K
389 default: // anything else
391 goto set_cluster_size;
392 case 2*1440: // 3.5", 2, 18, 80 - 1440K
393 case 2*2880: // 3.5", 2, 36, 80 - 2880K
397 // not floppy, but size matches floppy exactly.
398 // perhaps it is a floppy image.
399 // we already set media_byte as if it is a floppy,
400 // now set sect_per_track and heads.
402 sect_per_track = (unsigned)volume_size_sect / 160;
403 if (sect_per_track < 9)
409 // Calculate number of clusters, sectors/cluster, sectors/FAT
410 // (an initial guess for sect_per_clust should already be set)
412 // "mkdosfs -v -F 32 image5k 5" is the minimum:
413 // 2 sectors for FATs and 2 data sectors
414 if ((off_t)(volume_size_sect - reserved_sect) < 4)
415 bb_error_msg_and_die("the image is too small for FAT32");
420 uoff_t tcl = (volume_size_sect - reserved_sect - NUM_FATS * sect_per_fat) / sect_per_clust;
421 // tcl may be > MAX_CLUST_32 here, but it may be
422 // because sect_per_fat is underestimated,
423 // and with increased sect_per_fat it still may become
424 // <= MAX_CLUST_32. Therefore, we do not check
425 // against MAX_CLUST_32, but against a bigger const:
426 if (tcl > 0x80ffffff)
428 total_clust = tcl; // fits in uint32_t
429 // Every cluster needs 4 bytes in FAT. +2 entries since
430 // FAT has space for non-existent clusters 0 and 1.
431 // Let's see how many sectors that needs.
432 //May overflow at "*4":
433 //spf_adj = ((total_clust+2) * 4 + bytes_per_sect-1) / bytes_per_sect - sect_per_fat;
434 //Same in the more obscure, non-overflowing form:
435 spf_adj = ((total_clust+2) + (bytes_per_sect/4)-1) / (bytes_per_sect/4) - sect_per_fat;
437 bb_error_msg("sect_per_clust:%u sect_per_fat:%u total_clust:%u",
438 sect_per_clust, sect_per_fat, (int)tcl);
439 bb_error_msg("adjust to sect_per_fat:%d", spf_adj);
442 // do not need to adjust sect_per_fat.
443 // so, was total_clust too big after all?
444 if (total_clust <= MAX_CLUST_32)
445 goto found_total_clust; // no
446 // yes, total_clust is _a bit_ too big
449 // adjust sect_per_fat, go back and recalc total_clust
450 // (note: just "sect_per_fat += spf_adj" isn't ok)
451 sect_per_fat += ((unsigned)spf_adj / 2) | 1;
454 if (sect_per_clust == 128)
455 bb_error_msg_and_die("can't make FAT32 with >128 sectors/cluster");
457 sect_per_fat = (sect_per_fat / 2) | 1;
467 "heads:%u, sectors/track:%u, bytes/sector:%u\n"
468 "media descriptor:%02x\n"
469 "total sectors:%"OFF_FMT"u, clusters:%u, sectors/cluster:%u\n"
470 "FATs:2, sectors/FAT:%u\n"
471 "volumeID:%08x, label:'%s'\n",
473 heads, sect_per_track, bytes_per_sect,
475 volume_size_sect, (int)total_clust, (int)sect_per_clust,
477 (int)volume_id, volume_label
482 // Write filesystem image sequentially (no seeking)
485 // (a | b) is poor man's max(a, b)
486 unsigned bufsize = reserved_sect;
487 //bufsize |= sect_per_fat; // can be quite large
488 bufsize |= 2; // use this instead
489 bufsize |= sect_per_clust;
490 buf = xzalloc(bufsize * bytes_per_sect);
493 { // boot and fsinfo sectors, and their copies
494 struct msdos_boot_sector *boot_blk = (void*)buf;
495 struct fat32_fsinfo *info = (void*)(buf + bytes_per_sect);
497 strcpy(boot_blk->boot_jump_and_sys_id, "\xeb\x58\x90" "mkdosfs");
498 STORE_LE(boot_blk->bytes_per_sect, bytes_per_sect);
499 STORE_LE(boot_blk->sect_per_clust, sect_per_clust);
500 // cast in needed on big endian to suppress a warning
501 STORE_LE(boot_blk->reserved_sect, (uint16_t)reserved_sect);
502 STORE_LE(boot_blk->fats, 2);
503 //STORE_LE(boot_blk->dir_entries, 0); // for FAT32, stays 0
504 if (volume_size_sect <= 0xffff)
505 STORE_LE(boot_blk->volume_size_sect, volume_size_sect);
506 STORE_LE(boot_blk->media_byte, media_byte);
507 // wrong: this would make Linux think that it's fat12/16:
508 //if (sect_per_fat <= 0xffff)
509 // STORE_LE(boot_blk->sect_per_fat, sect_per_fat);
511 //STORE_LE(boot_blk->sect_per_fat, 0);
512 STORE_LE(boot_blk->sect_per_track, sect_per_track);
513 STORE_LE(boot_blk->heads, heads);
514 //STORE_LE(boot_blk->hidden, 0);
515 STORE_LE(boot_blk->fat32_volume_size_sect, volume_size_sect);
516 STORE_LE(boot_blk->fat32_sect_per_fat, sect_per_fat);
517 //STORE_LE(boot_blk->fat32_flags, 0);
518 //STORE_LE(boot_blk->fat32_version[2], 0,0);
519 STORE_LE(boot_blk->fat32_root_cluster, 2);
520 STORE_LE(boot_blk->fat32_info_sector, info_sector_number);
521 STORE_LE(boot_blk->fat32_backup_boot, backup_boot_sector);
522 //STORE_LE(boot_blk->reserved2[3], 0,0,0);
523 STORE_LE(boot_blk->vi.ext_boot_sign, 0x29);
524 STORE_LE(boot_blk->vi.volume_id32, volume_id);
525 strncpy(boot_blk->vi.fs_type, "FAT32 ", sizeof(boot_blk->vi.fs_type));
526 strncpy(boot_blk->vi.volume_label, volume_label, sizeof(boot_blk->vi.volume_label));
527 memcpy(boot_blk->boot_code, boot_code, sizeof(boot_code));
528 STORE_LE(boot_blk->boot_sign, BOOT_SIGN);
530 STORE_LE(info->signature1, FAT_FSINFO_SIG1);
531 STORE_LE(info->signature2, FAT_FSINFO_SIG2);
532 // we've allocated cluster 2 for the root dir
533 STORE_LE(info->free_clusters, (total_clust - 1));
534 STORE_LE(info->next_cluster, 2);
535 STORE_LE(info->boot_sign, BOOT_SIGN);
538 xwrite(dev, buf, bytes_per_sect * backup_boot_sector);
539 // 2nd copy and possibly zero sectors
540 xwrite(dev, buf, bytes_per_sect * (reserved_sect - backup_boot_sector));
543 { // file allocation tables
545 unsigned char *fat = (void*)buf;
547 memset(buf, 0, bytes_per_sect * 2);
548 // initial FAT entries
549 MARK_CLUSTER(0, 0x0fffff00 | media_byte);
550 MARK_CLUSTER(1, 0xffffffff);
551 // mark cluster 2 as EOF (used for root dir)
552 MARK_CLUSTER(2, EOF_FAT32);
553 for (i = 0; i < NUM_FATS; i++) {
554 xwrite(dev, buf, bytes_per_sect);
555 for (j = 1; j < sect_per_fat; j++)
556 xwrite(dev, buf + bytes_per_sect, bytes_per_sect);
561 // empty directory is just a set of zero bytes
562 memset(buf, 0, sect_per_clust * bytes_per_sect);
563 if (volume_label[0]) {
564 // create dir entry for volume_label
565 struct msdos_dir_entry *de;
571 strncpy(de->name, volume_label, sizeof(de->name));
572 STORE_LE(de->attr, ATTR_VOLUME);
574 localtime_r(&create_time, &tm_time);
575 t = (tm_time.tm_sec >> 1) + (tm_time.tm_min << 5) + (tm_time.tm_hour << 11);
576 d = tm_time.tm_mday + ((tm_time.tm_mon+1) << 5) + ((tm_time.tm_year-80) << 9);
577 STORE_LE(de->time, t);
578 STORE_LE(de->date, d);
579 //STORE_LE(de->ctime_cs, 0);
580 de->ctime = de->time;
581 de->cdate = de->date;
582 de->adate = de->date;
585 xwrite(dev, buf, sect_per_clust * bytes_per_sect);
589 uoff_t volume_size_blocks;
590 unsigned start_data_sector;
591 unsigned start_data_block;
592 unsigned badblocks = 0;
594 off_t currently_testing;
595 char *blkbuf = xmalloc(BLOCK_SIZE * TEST_BUFFER_BLOCKS);
597 volume_size_blocks = (volume_size_bytes >> BLOCK_SIZE_BITS);
598 // N.B. the two following vars are in hard sectors, i.e. SECTOR_SIZE byte sectors!
599 start_data_sector = (reserved_sect + NUM_FATS * sect_per_fat) * (bytes_per_sect / SECTOR_SIZE);
600 start_data_block = (start_data_sector + SECTORS_PER_BLOCK - 1) / SECTORS_PER_BLOCK;
602 bb_error_msg("searching for bad blocks");
603 currently_testing = 0;
604 try = TEST_BUFFER_BLOCKS;
605 while (currently_testing < volume_size_blocks) {
606 if (currently_testing + try > volume_size_blocks)
607 try = volume_size_blocks - currently_testing;
608 // perform a test on a block. return the number of blocks
609 // that could be read successfully.
610 // seek to the correct location
611 xlseek(dev, currently_testing * BLOCK_SIZE, SEEK_SET);
613 got = read(dev, blkbuf, try * BLOCK_SIZE);
616 if (got & (BLOCK_SIZE - 1))
617 bb_error_msg("unexpected values in do_check: probably bugs");
619 currently_testing += got;
621 try = TEST_BUFFER_BLOCKS;
625 if (currently_testing < start_data_block)
626 bb_error_msg_and_die("bad blocks before data-area: cannot make fs");
628 // mark all of the sectors in the block as bad
629 for (i = 0; i < SECTORS_PER_BLOCK; i++) {
630 int cluster = (currently_testing * SECTORS_PER_BLOCK + i - start_data_sector) / (int) (sect_per_clust) / (bytes_per_sect / SECTOR_SIZE);
632 bb_error_msg_and_die("invalid cluster number in mark_sector: probably bug!");
633 MARK_CLUSTER(cluster, BAD_FAT32);
640 bb_error_msg("%d bad block(s)", badblocks);
645 if (ENABLE_FEATURE_CLEAN_UP) {