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1/* vi: set sw=4 ts=4: */
2/*
3 * mkfs_vfat: utility to create FAT32 filesystem
4 * inspired by dosfstools
5 *
6 * Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
7 *
8 * Licensed under GPLv2, see file LICENSE in this source tree.
9 */
10//config:config MKDOSFS
11//config: bool "mkdosfs"
12//config: default y
13//config: select PLATFORM_LINUX
14//config: help
15//config: Utility to create FAT32 filesystems.
16//config:
17//config:config MKFS_VFAT
18//config: bool "mkfs.vfat"
19//config: default y
20//config: select PLATFORM_LINUX
21//config: help
22//config: Alias to "mkdosfs".
23
24//applet:IF_MKDOSFS(APPLET_ODDNAME(mkdosfs, mkfs_vfat, BB_DIR_SBIN, BB_SUID_DROP, mkfs_vfat))
25//applet:IF_MKFS_VFAT(APPLET_ODDNAME(mkfs.vfat, mkfs_vfat, BB_DIR_SBIN, BB_SUID_DROP, mkfs_vfat))
26
27//kbuild:lib-$(CONFIG_MKDOSFS) += mkfs_vfat.o
28//kbuild:lib-$(CONFIG_MKFS_VFAT) += mkfs_vfat.o
29
30//usage:#define mkfs_vfat_trivial_usage
31//usage: "[-v] [-n LABEL] BLOCKDEV [KBYTES]"
32/* Accepted but ignored:
33 "[-c] [-C] [-I] [-l bad-block-file] [-b backup-boot-sector] "
34 "[-m boot-msg-file] [-i volume-id] "
35 "[-s sectors-per-cluster] [-S logical-sector-size] [-f number-of-FATs] "
36 "[-h hidden-sectors] [-F fat-size] [-r root-dir-entries] [-R reserved-sectors] "
37*/
38//usage:#define mkfs_vfat_full_usage "\n\n"
39//usage: "Make a FAT32 filesystem\n"
40/* //usage: "\n -c Check device for bad blocks" */
41//usage: "\n -v Verbose"
42/* //usage: "\n -I Allow to use entire disk device (e.g. /dev/hda)" */
43//usage: "\n -n LBL Volume label"
44
45#include "libbb.h"
46
47#include <linux/hdreg.h> /* HDIO_GETGEO */
48#include <linux/fd.h> /* FDGETPRM */
49#include <sys/mount.h> /* BLKSSZGET */
50#if !defined(BLKSSZGET)
51# define BLKSSZGET _IO(0x12, 104)
52#endif
53//#include <linux/msdos_fs.h>
54
55#define SECTOR_SIZE 512
56
57#define SECTORS_PER_BLOCK (BLOCK_SIZE / SECTOR_SIZE)
58
59// M$ says the high 4 bits of a FAT32 FAT entry are reserved
60#define EOF_FAT32 0x0FFFFFF8
61#define BAD_FAT32 0x0FFFFFF7
62#define MAX_CLUST_32 0x0FFFFFF0
63
64#define ATTR_VOLUME 8
65
66#define NUM_FATS 2
67
68/* FAT32 filesystem looks like this:
69 * sector -nn...-1: "hidden" sectors, all sectors before this partition
70 * (-h hidden-sectors sets it. Useful only for boot loaders,
71 * they need to know _disk_ offset in order to be able to correctly
72 * address sectors relative to start of disk)
73 * sector 0: boot sector
74 * sector 1: info sector
75 * sector 2: set aside for boot code which didn't fit into sector 0
76 * ...(zero-filled sectors)...
77 * sector B: backup copy of sector 0 [B set by -b backup-boot-sector]
78 * sector B+1: backup copy of sector 1
79 * sector B+2: backup copy of sector 2
80 * ...(zero-filled sectors)...
81 * sector R: FAT#1 [R set by -R reserved-sectors]
82 * ...(FAT#1)...
83 * sector R+fat_size: FAT#2
84 * ...(FAT#2)...
85 * sector R+fat_size*2: cluster #2
86 * ...(cluster #2)...
87 * sector R+fat_size*2+clust_size: cluster #3
88 * ...(the rest is filled by clusters till the end)...
89 */
90
91enum {
92// Perhaps this should remain constant
93 info_sector_number = 1,
94// TODO: make these cmdline options
95// dont forget sanity check: backup_boot_sector + 3 <= reserved_sect
96 backup_boot_sector = 3,
97 reserved_sect = 6,
98};
99
100// how many blocks we try to read while testing
101#define TEST_BUFFER_BLOCKS 16
102
103struct msdos_dir_entry {
104 char name[11]; /* 000 name and extension */
105 uint8_t attr; /* 00b attribute bits */
106 uint8_t lcase; /* 00c case for base and extension */
107 uint8_t ctime_cs; /* 00d creation time, centiseconds (0-199) */
108 uint16_t ctime; /* 00e creation time */
109 uint16_t cdate; /* 010 creation date */
110 uint16_t adate; /* 012 last access date */
111 uint16_t starthi; /* 014 high 16 bits of cluster in FAT32 */
112 uint16_t time; /* 016 time */
113 uint16_t date; /* 018 date */
114 uint16_t start; /* 01a first cluster */
115 uint32_t size; /* 01c file size in bytes */
116} PACKED;
117
118/* Example of boot sector's beginning:
1190000 eb 58 90 4d 53 57 49 4e 34 2e 31 00 02 08 26 00 |...MSWIN4.1...&.|
1200010 02 00 00 00 00 f8 00 00 3f 00 ff 00 3f 00 00 00 |........?...?...|
1210020 54 9b d0 00 0d 34 00 00 00 00 00 00 02 00 00 00 |T....4..........|
1220030 01 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
1230040 80 00 29 71 df 51 e0 4e 4f 20 4e 41 4d 45 20 20 |..)q.Q.NO NAME |
1240050 20 20 46 41 54 33 32 20 20 20 33 c9 8e d1 bc f4 | FAT32 3.....|
125*/
126struct msdos_volume_info { /* (offsets are relative to start of boot sector) */
127 uint8_t drive_number; /* 040 BIOS drive number */
128 uint8_t reserved; /* 041 unused */
129 uint8_t ext_boot_sign; /* 042 0x29 if fields below exist (DOS 3.3+) */
130 uint32_t volume_id32; /* 043 volume ID number */
131 char volume_label[11];/* 047 volume label */
132 char fs_type[8]; /* 052 typically "FATnn" */
133} PACKED; /* 05a end. Total size 26 (0x1a) bytes */
134
135struct msdos_boot_sector {
136 /* We use strcpy to fill both, and gcc-4.4.x complains if they are separate */
137 char boot_jump_and_sys_id[3+8]; /* 000 short or near jump instruction */
138 /*char system_id[8];*/ /* 003 name - can be used to special case partition manager volumes */
139 uint16_t bytes_per_sect; /* 00b bytes per logical sector */
140 uint8_t sect_per_clust; /* 00d sectors/cluster */
141 uint16_t reserved_sect; /* 00e reserved sectors (sector offset of 1st FAT relative to volume start) */
142 uint8_t fats; /* 010 number of FATs */
143 uint16_t dir_entries; /* 011 root directory entries */
144 uint16_t volume_size_sect; /* 013 volume size in sectors */
145 uint8_t media_byte; /* 015 media code */
146 uint16_t sect_per_fat; /* 016 sectors/FAT */
147 uint16_t sect_per_track; /* 018 sectors per track */
148 uint16_t heads; /* 01a number of heads */
149 uint32_t hidden; /* 01c hidden sectors (sector offset of volume within physical disk) */
150 uint32_t fat32_volume_size_sect; /* 020 volume size in sectors (if volume_size_sect == 0) */
151 uint32_t fat32_sect_per_fat; /* 024 sectors/FAT */
152 uint16_t fat32_flags; /* 028 bit 8: fat mirroring, low 4: active fat */
153 uint8_t fat32_version[2]; /* 02a major, minor filesystem version (I see 0,0) */
154 uint32_t fat32_root_cluster; /* 02c first cluster in root directory */
155 uint16_t fat32_info_sector; /* 030 filesystem info sector (usually 1) */
156 uint16_t fat32_backup_boot; /* 032 backup boot sector (usually 6) */
157 uint32_t reserved2[3]; /* 034 unused */
158 struct msdos_volume_info vi; /* 040 */
159 char boot_code[0x200 - 0x5a - 2]; /* 05a */
160#define BOOT_SIGN 0xAA55
161 uint16_t boot_sign; /* 1fe */
162} PACKED;
163
164#define FAT_FSINFO_SIG1 0x41615252
165#define FAT_FSINFO_SIG2 0x61417272
166struct fat32_fsinfo {
167 uint32_t signature1; /* 0x52,0x52,0x41,0x61, "RRaA" */
168 uint32_t reserved1[128 - 8];
169 uint32_t signature2; /* 0x72,0x72,0x61,0x41, "rrAa" */
170 uint32_t free_clusters; /* free cluster count. -1 if unknown */
171 uint32_t next_cluster; /* most recently allocated cluster */
172 uint32_t reserved2[3];
173 uint16_t reserved3; /* 1fc */
174 uint16_t boot_sign; /* 1fe */
175} PACKED;
176
177struct bug_check {
178 char BUG1[sizeof(struct msdos_dir_entry ) == 0x20 ? 1 : -1];
179 char BUG2[sizeof(struct msdos_volume_info) == 0x1a ? 1 : -1];
180 char BUG3[sizeof(struct msdos_boot_sector) == 0x200 ? 1 : -1];
181 char BUG4[sizeof(struct fat32_fsinfo ) == 0x200 ? 1 : -1];
182};
183
184static const char boot_code[] ALIGN1 =
185 "\x0e" /* 05a: push cs */
186 "\x1f" /* 05b: pop ds */
187 "\xbe\x77\x7c" /* write_msg: mov si, offset message_txt */
188 "\xac" /* 05f: lodsb */
189 "\x22\xc0" /* 060: and al, al */
190 "\x74\x0b" /* 062: jz key_press */
191 "\x56" /* 064: push si */
192 "\xb4\x0e" /* 065: mov ah, 0eh */
193 "\xbb\x07\x00" /* 067: mov bx, 0007h */
194 "\xcd\x10" /* 06a: int 10h */
195 "\x5e" /* 06c: pop si */
196 "\xeb\xf0" /* 06d: jmp write_msg */
197 "\x32\xe4" /* key_press: xor ah, ah */
198 "\xcd\x16" /* 071: int 16h */
199 "\xcd\x19" /* 073: int 19h */
200 "\xeb\xfe" /* foo: jmp foo */
201 /* 077: message_txt: */
202 "This is not a bootable disk\r\n";
203
204
205#define MARK_CLUSTER(cluster, value) \
206 ((uint32_t *)fat)[cluster] = SWAP_LE32(value)
207
208void BUG_unsupported_field_size(void);
209#define STORE_LE(field, value) \
210do { \
211 if (sizeof(field) == 4) \
212 field = SWAP_LE32(value); \
213 else if (sizeof(field) == 2) \
214 field = SWAP_LE16(value); \
215 else if (sizeof(field) == 1) \
216 field = (value); \
217 else \
218 BUG_unsupported_field_size(); \
219} while (0)
220
221/* compat:
222 * mkdosfs 2.11 (12 Mar 2005)
223 * Usage: mkdosfs [-A] [-c] [-C] [-v] [-I] [-l bad-block-file]
224 * [-b backup-boot-sector]
225 * [-m boot-msg-file] [-n volume-name] [-i volume-id]
226 * [-s sectors-per-cluster] [-S logical-sector-size]
227 * [-f number-of-FATs]
228 * [-h hidden-sectors] [-F fat-size] [-r root-dir-entries]
229 * [-R reserved-sectors]
230 * /dev/name [blocks]
231 */
232int mkfs_vfat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
233int mkfs_vfat_main(int argc UNUSED_PARAM, char **argv)
234{
235 struct stat st;
236 const char *volume_label = "";
237 char *buf;
238 char *device_name;
239 uoff_t volume_size_bytes;
240 uoff_t volume_size_sect;
241 uint32_t total_clust;
242 uint32_t volume_id;
243 int dev;
244 unsigned bytes_per_sect;
245 unsigned sect_per_fat;
246 unsigned opts;
247 uint16_t sect_per_track;
248 uint8_t media_byte;
249 uint8_t sect_per_clust;
250 uint8_t heads;
251 enum {
252 OPT_A = 1 << 0, // [IGNORED] atari format
253 OPT_b = 1 << 1, // [IGNORED] location of backup boot sector
254 OPT_c = 1 << 2, // [IGNORED] check filesystem
255 OPT_C = 1 << 3, // [IGNORED] create a new file
256 OPT_f = 1 << 4, // [IGNORED] number of FATs
257 OPT_F = 1 << 5, // [IGNORED, implied 32] choose FAT size
258 OPT_h = 1 << 6, // [IGNORED] number of hidden sectors
259 OPT_I = 1 << 7, // [IGNORED] don't bark at entire disk devices
260 OPT_i = 1 << 8, // [IGNORED] volume ID
261 OPT_l = 1 << 9, // [IGNORED] bad block filename
262 OPT_m = 1 << 10, // [IGNORED] message file
263 OPT_n = 1 << 11, // volume label
264 OPT_r = 1 << 12, // [IGNORED] root directory entries
265 OPT_R = 1 << 13, // [IGNORED] number of reserved sectors
266 OPT_s = 1 << 14, // [IGNORED] sectors per cluster
267 OPT_S = 1 << 15, // [IGNORED] sector size
268 OPT_v = 1 << 16, // verbose
269 };
270
271 opt_complementary = "-1";//:b+:f+:F+:h+:r+:R+:s+:S+:vv:c--l:l--c";
272 opts = getopt32(argv, "Ab:cCf:F:h:Ii:l:m:n:r:R:s:S:v",
273 NULL, NULL, NULL, NULL, NULL,
274 NULL, NULL, &volume_label, NULL, NULL, NULL, NULL);
275 argv += optind;
276
277 // cache device name
278 device_name = argv[0];
279 // default volume ID = creation time
280 volume_id = time(NULL);
281
282 dev = xopen(device_name, O_RDWR);
283 xfstat(dev, &st, device_name);
284
285 //
286 // Get image size and sector size
287 //
288 bytes_per_sect = SECTOR_SIZE;
289 if (!S_ISBLK(st.st_mode)) {
290 if (!S_ISREG(st.st_mode)) {
291 if (!argv[1])
292 bb_error_msg_and_die("image size must be specified");
293 }
294 // not a block device, skip bad sectors check
295 opts &= ~OPT_c;
296 } else {
297 int min_bytes_per_sect;
298#if 0
299 unsigned device_num;
300 // for true block devices we do check sanity
301 device_num = st.st_rdev & 0xff3f;
302 // do we allow to format the whole disk device?
303 if (!(opts & OPT_I) && (
304 device_num == 0x0300 || // hda, hdb
305 (device_num & 0xff0f) == 0x0800 || // sd
306 device_num == 0x0d00 || // xd
307 device_num == 0x1600 ) // hdc, hdd
308 )
309 bb_error_msg_and_die("will not try to make filesystem on full-disk device (use -I if wanted)");
310 // can't work on mounted filesystems
311 if (find_mount_point(device_name, 0))
312 bb_error_msg_and_die("can't format mounted filesystem");
313#endif
314 // get true sector size
315 // (parameter must be int*, not long* or size_t*)
316 xioctl(dev, BLKSSZGET, &min_bytes_per_sect);
317 if (min_bytes_per_sect > SECTOR_SIZE) {
318 bytes_per_sect = min_bytes_per_sect;
319 bb_error_msg("for this device sector size is %u", min_bytes_per_sect);
320 }
321 }
322 volume_size_bytes = get_volume_size_in_bytes(dev, argv[1], 1024, /*extend:*/ 1);
323 volume_size_sect = volume_size_bytes / bytes_per_sect;
324
325 //
326 // Find out or guess media parameters
327 //
328 media_byte = 0xf8;
329 heads = 255;
330 sect_per_track = 63;
331 sect_per_clust = 1;
332 {
333 struct hd_geometry geometry;
334 // size (in sectors), sect (per track), head
335 struct floppy_struct param;
336
337 // N.B. whether to use HDIO_GETGEO or HDIO_REQ?
338 if (ioctl(dev, HDIO_GETGEO, &geometry) == 0
339 && geometry.sectors
340 && geometry.heads
341 ) {
342 // hard drive
343 sect_per_track = geometry.sectors;
344 heads = geometry.heads;
345
346 set_cluster_size:
347 /* For FAT32, try to do the same as M$'s format command
348 * (see http://www.win.tue.nl/~aeb/linux/fs/fat/fatgen103.pdf p. 20):
349 * fs size <= 260M: 0.5k clusters
350 * fs size <= 8G: 4k clusters
351 * fs size <= 16G: 8k clusters
352 * fs size > 16G: 16k clusters
353 */
354 sect_per_clust = 1;
355 if (volume_size_bytes >= 260*1024*1024) {
356 sect_per_clust = 8;
357 /* fight gcc: */
358 /* "error: integer overflow in expression" */
359 /* "error: right shift count >= width of type" */
360 if (sizeof(off_t) > 4) {
361 unsigned t = (volume_size_bytes >> 31 >> 1);
362 if (t >= 8/4)
363 sect_per_clust = 16;
364 if (t >= 16/4)
365 sect_per_clust = 32;
366 }
367 }
368 } else {
369 // floppy, loop, or regular file
370 int not_floppy = ioctl(dev, FDGETPRM, &param);
371 if (not_floppy == 0) {
372 // floppy disk
373 sect_per_track = param.sect;
374 heads = param.head;
375 volume_size_sect = param.size;
376 volume_size_bytes = param.size * SECTOR_SIZE;
377 }
378 // setup the media descriptor byte
379 switch (volume_size_sect) {
380 case 2*360: // 5.25", 2, 9, 40 - 360K
381 media_byte = 0xfd;
382 break;
383 case 2*720: // 3.5", 2, 9, 80 - 720K
384 case 2*1200: // 5.25", 2, 15, 80 - 1200K
385 media_byte = 0xf9;
386 break;
387 default: // anything else
388 if (not_floppy)
389 goto set_cluster_size;
390 case 2*1440: // 3.5", 2, 18, 80 - 1440K
391 case 2*2880: // 3.5", 2, 36, 80 - 2880K
392 media_byte = 0xf0;
393 break;
394 }
395 // not floppy, but size matches floppy exactly.
396 // perhaps it is a floppy image.
397 // we already set media_byte as if it is a floppy,
398 // now set sect_per_track and heads.
399 heads = 2;
400 sect_per_track = (unsigned)volume_size_sect / 160;
401 if (sect_per_track < 9)
402 sect_per_track = 9;
403 }
404 }
405
406 //
407 // Calculate number of clusters, sectors/cluster, sectors/FAT
408 // (an initial guess for sect_per_clust should already be set)
409 //
410 // "mkdosfs -v -F 32 image5k 5" is the minimum:
411 // 2 sectors for FATs and 2 data sectors
412 if ((off_t)(volume_size_sect - reserved_sect) < 4)
413 bb_error_msg_and_die("the image is too small for FAT32");
414 sect_per_fat = 1;
415 while (1) {
416 while (1) {
417 int spf_adj;
418 uoff_t tcl = (volume_size_sect - reserved_sect - NUM_FATS * sect_per_fat) / sect_per_clust;
419 // tcl may be > MAX_CLUST_32 here, but it may be
420 // because sect_per_fat is underestimated,
421 // and with increased sect_per_fat it still may become
422 // <= MAX_CLUST_32. Therefore, we do not check
423 // against MAX_CLUST_32, but against a bigger const:
424 if (tcl > 0x80ffffff)
425 goto next;
426 total_clust = tcl; // fits in uint32_t
427 // Every cluster needs 4 bytes in FAT. +2 entries since
428 // FAT has space for non-existent clusters 0 and 1.
429 // Let's see how many sectors that needs.
430 //May overflow at "*4":
431 //spf_adj = ((total_clust+2) * 4 + bytes_per_sect-1) / bytes_per_sect - sect_per_fat;
432 //Same in the more obscure, non-overflowing form:
433 spf_adj = ((total_clust+2) + (bytes_per_sect/4)-1) / (bytes_per_sect/4) - sect_per_fat;
434#if 0
435 bb_error_msg("sect_per_clust:%u sect_per_fat:%u total_clust:%u",
436 sect_per_clust, sect_per_fat, (int)tcl);
437 bb_error_msg("adjust to sect_per_fat:%d", spf_adj);
438#endif
439 if (spf_adj <= 0) {
440 // do not need to adjust sect_per_fat.
441 // so, was total_clust too big after all?
442 if (total_clust <= MAX_CLUST_32)
443 goto found_total_clust; // no
444 // yes, total_clust is _a bit_ too big
445 goto next;
446 }
447 // adjust sect_per_fat, go back and recalc total_clust
448 // (note: just "sect_per_fat += spf_adj" isn't ok)
449 sect_per_fat += ((unsigned)spf_adj / 2) | 1;
450 }
451 next:
452 if (sect_per_clust == 128)
453 bb_error_msg_and_die("can't make FAT32 with >128 sectors/cluster");
454 sect_per_clust *= 2;
455 sect_per_fat = (sect_per_fat / 2) | 1;
456 }
457 found_total_clust:
458
459 //
460 // Print info
461 //
462 if (opts & OPT_v) {
463 fprintf(stderr,
464 "Device '%s':\n"
465 "heads:%u, sectors/track:%u, bytes/sector:%u\n"
466 "media descriptor:%02x\n"
467 "total sectors:%"OFF_FMT"u, clusters:%u, sectors/cluster:%u\n"
468 "FATs:2, sectors/FAT:%u\n"
469 "volumeID:%08x, label:'%s'\n",
470 device_name,
471 heads, sect_per_track, bytes_per_sect,
472 (int)media_byte,
473 volume_size_sect, (int)total_clust, (int)sect_per_clust,
474 sect_per_fat,
475 (int)volume_id, volume_label
476 );
477 }
478
479 //
480 // Write filesystem image sequentially (no seeking)
481 //
482 {
483 // (a | b) is poor man's max(a, b)
484 unsigned bufsize = reserved_sect;
485 //bufsize |= sect_per_fat; // can be quite large
486 bufsize |= 2; // use this instead
487 bufsize |= sect_per_clust;
488 buf = xzalloc(bufsize * bytes_per_sect);
489 }
490
491 { // boot and fsinfo sectors, and their copies
492 struct msdos_boot_sector *boot_blk = (void*)buf;
493 struct fat32_fsinfo *info = (void*)(buf + bytes_per_sect);
494
495 strcpy(boot_blk->boot_jump_and_sys_id, "\xeb\x58\x90" "mkdosfs");
496 STORE_LE(boot_blk->bytes_per_sect, bytes_per_sect);
497 STORE_LE(boot_blk->sect_per_clust, sect_per_clust);
498 // cast in needed on big endian to suppress a warning
499 STORE_LE(boot_blk->reserved_sect, (uint16_t)reserved_sect);
500 STORE_LE(boot_blk->fats, 2);
501 //STORE_LE(boot_blk->dir_entries, 0); // for FAT32, stays 0
502 if (volume_size_sect <= 0xffff)
503 STORE_LE(boot_blk->volume_size_sect, volume_size_sect);
504 STORE_LE(boot_blk->media_byte, media_byte);
505 // wrong: this would make Linux think that it's fat12/16:
506 //if (sect_per_fat <= 0xffff)
507 // STORE_LE(boot_blk->sect_per_fat, sect_per_fat);
508 // works:
509 //STORE_LE(boot_blk->sect_per_fat, 0);
510 STORE_LE(boot_blk->sect_per_track, sect_per_track);
511 STORE_LE(boot_blk->heads, heads);
512 //STORE_LE(boot_blk->hidden, 0);
513 STORE_LE(boot_blk->fat32_volume_size_sect, volume_size_sect);
514 STORE_LE(boot_blk->fat32_sect_per_fat, sect_per_fat);
515 //STORE_LE(boot_blk->fat32_flags, 0);
516 //STORE_LE(boot_blk->fat32_version[2], 0,0);
517 STORE_LE(boot_blk->fat32_root_cluster, 2);
518 STORE_LE(boot_blk->fat32_info_sector, info_sector_number);
519 STORE_LE(boot_blk->fat32_backup_boot, backup_boot_sector);
520 //STORE_LE(boot_blk->reserved2[3], 0,0,0);
521 STORE_LE(boot_blk->vi.ext_boot_sign, 0x29);
522 STORE_LE(boot_blk->vi.volume_id32, volume_id);
523 strncpy(boot_blk->vi.fs_type, "FAT32 ", sizeof(boot_blk->vi.fs_type));
524 strncpy(boot_blk->vi.volume_label, volume_label, sizeof(boot_blk->vi.volume_label));
525 memcpy(boot_blk->boot_code, boot_code, sizeof(boot_code));
526 STORE_LE(boot_blk->boot_sign, BOOT_SIGN);
527
528 STORE_LE(info->signature1, FAT_FSINFO_SIG1);
529 STORE_LE(info->signature2, FAT_FSINFO_SIG2);
530 // we've allocated cluster 2 for the root dir
531 STORE_LE(info->free_clusters, (total_clust - 1));
532 STORE_LE(info->next_cluster, 2);
533 STORE_LE(info->boot_sign, BOOT_SIGN);
534
535 // 1st copy
536 xwrite(dev, buf, bytes_per_sect * backup_boot_sector);
537 // 2nd copy and possibly zero sectors
538 xwrite(dev, buf, bytes_per_sect * (reserved_sect - backup_boot_sector));
539 }
540
541 { // file allocation tables
542 unsigned i,j;
543 unsigned char *fat = (void*)buf;
544
545 memset(buf, 0, bytes_per_sect * 2);
546 // initial FAT entries
547 MARK_CLUSTER(0, 0x0fffff00 | media_byte);
548 MARK_CLUSTER(1, 0xffffffff);
549 // mark cluster 2 as EOF (used for root dir)
550 MARK_CLUSTER(2, EOF_FAT32);
551 for (i = 0; i < NUM_FATS; i++) {
552 xwrite(dev, buf, bytes_per_sect);
553 for (j = 1; j < sect_per_fat; j++)
554 xwrite(dev, buf + bytes_per_sect, bytes_per_sect);
555 }
556 }
557
558 // root directory
559 // empty directory is just a set of zero bytes
560 memset(buf, 0, sect_per_clust * bytes_per_sect);
561 if (volume_label[0]) {
562 // create dir entry for volume_label
563 struct msdos_dir_entry *de;
564#if 0
565 struct tm tm_time;
566 uint16_t t, d;
567#endif
568 de = (void*)buf;
569 strncpy(de->name, volume_label, sizeof(de->name));
570 STORE_LE(de->attr, ATTR_VOLUME);
571#if 0
572 localtime_r(&create_time, &tm_time);
573 t = (tm_time.tm_sec >> 1) + (tm_time.tm_min << 5) + (tm_time.tm_hour << 11);
574 d = tm_time.tm_mday + ((tm_time.tm_mon+1) << 5) + ((tm_time.tm_year-80) << 9);
575 STORE_LE(de->time, t);
576 STORE_LE(de->date, d);
577 //STORE_LE(de->ctime_cs, 0);
578 de->ctime = de->time;
579 de->cdate = de->date;
580 de->adate = de->date;
581#endif
582 }
583 xwrite(dev, buf, sect_per_clust * bytes_per_sect);
584
585#if 0
586 if (opts & OPT_c) {
587 uoff_t volume_size_blocks;
588 unsigned start_data_sector;
589 unsigned start_data_block;
590 unsigned badblocks = 0;
591 int try, got;
592 off_t currently_testing;
593 char *blkbuf = xmalloc(BLOCK_SIZE * TEST_BUFFER_BLOCKS);
594
595 volume_size_blocks = (volume_size_bytes >> BLOCK_SIZE_BITS);
596 // N.B. the two following vars are in hard sectors, i.e. SECTOR_SIZE byte sectors!
597 start_data_sector = (reserved_sect + NUM_FATS * sect_per_fat) * (bytes_per_sect / SECTOR_SIZE);
598 start_data_block = (start_data_sector + SECTORS_PER_BLOCK - 1) / SECTORS_PER_BLOCK;
599
600 bb_error_msg("searching for bad blocks");
601 currently_testing = 0;
602 try = TEST_BUFFER_BLOCKS;
603 while (currently_testing < volume_size_blocks) {
604 if (currently_testing + try > volume_size_blocks)
605 try = volume_size_blocks - currently_testing;
606 // perform a test on a block. return the number of blocks
607 // that could be read successfully.
608 // seek to the correct location
609 xlseek(dev, currently_testing * BLOCK_SIZE, SEEK_SET);
610 // try reading
611 got = read(dev, blkbuf, try * BLOCK_SIZE);
612 if (got < 0)
613 got = 0;
614 if (got & (BLOCK_SIZE - 1))
615 bb_error_msg("unexpected values in do_check: probably bugs");
616 got /= BLOCK_SIZE;
617 currently_testing += got;
618 if (got == try) {
619 try = TEST_BUFFER_BLOCKS;
620 continue;
621 }
622 try = 1;
623 if (currently_testing < start_data_block)
624 bb_error_msg_and_die("bad blocks before data-area: cannot make fs");
625
626 // mark all of the sectors in the block as bad
627 for (i = 0; i < SECTORS_PER_BLOCK; i++) {
628 int cluster = (currently_testing * SECTORS_PER_BLOCK + i - start_data_sector) / (int) (sect_per_clust) / (bytes_per_sect / SECTOR_SIZE);
629 if (cluster < 0)
630 bb_error_msg_and_die("invalid cluster number in mark_sector: probably bug!");
631 MARK_CLUSTER(cluster, BAD_FAT32);
632 }
633 badblocks++;
634 currently_testing++;
635 }
636 free(blkbuf);
637 if (badblocks)
638 bb_error_msg("%d bad block(s)", badblocks);
639 }
640#endif
641
642 // cleanup
643 if (ENABLE_FEATURE_CLEAN_UP) {
644 free(buf);
645 close(dev);
646 }
647
648 return 0;
649}
650
generated by cgit at 2024-05-15 01:14:13 (GMT)