source: mainline/uspace/app/mkexfat/mkexfat.c@ ba55c194

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since ba55c194 was ba55c194, checked in by Maurizio Lombardi <m.lombardi85@…>, 13 years ago

mkexfat: fix comment.
  • Property mode set to 100644
File size: 17.6 KB
Line 
1/*
2 * Copyright (c) 2012 Maurizio Lombardi
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 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup fs
30 * @{
31 */
32
33/**
34 * @file mkexfat.c
35 * @brief Tool for creating new exFAT file systems.
36 *
37 */
38
39#include <stdio.h>
40#include <libblock.h>
41#include <assert.h>
42#include <errno.h>
43#include <malloc.h>
44#include <byteorder.h>
45#include <align.h>
46#include <sys/types.h>
47#include <sys/typefmt.h>
48#include <bool.h>
49#include "exfat.h"
50#include "upcase.h"
51
52#define NAME "mkexfat"
53
54/** First sector of the FAT */
55#define FAT_SECTOR_START 128
56
57/** First sector of the Main Extended Boot Region */
58#define EBS_SECTOR_START 1
59
60/** First sector of the Main Extended Boot Region Backup */
61#define EBS_BACKUP_SECTOR_START 13
62
63/** First sector of the Main Boot Sector */
64#define MBS_SECTOR 0
65
66/** First sector of the Main Boot Sector Backup */
67#define MBS_BACKUP_SECTOR 12
68
69/** Size of the Main Extended Boot Region */
70#define EBS_SIZE 8
71
72/** Divide and round up. */
73#define div_round_up(a, b) (((a) + (b) - 1) / (b))
74
75/** The default size of each cluster is 4096 byte */
76#define DEFAULT_CLUSTER_SIZE 4096
77
78/** Index of the first free cluster on the device */
79#define FIRST_FREE_CLUSTER 2
80
81#define min(x, y) ((x) < (y) ? (x) : (y))
82
83typedef struct exfat_cfg {
84 aoff64_t volume_start;
85 aoff64_t volume_count;
86 unsigned long fat_sector_count;
87 unsigned long data_start_sector;
88 unsigned long rootdir_cluster;
89 unsigned long upcase_table_cluster;
90 unsigned long total_clusters;
91 unsigned long allocated_clusters;
92 size_t bitmap_size;
93 size_t sector_size;
94 size_t cluster_size;
95} exfat_cfg_t;
96
97
98static unsigned log2(unsigned n);
99
100static uint32_t
101vbr_checksum_start(void const *octets, size_t nbytes);
102
103static void
104vbr_checksum_update(void const *octets, size_t nbytes, uint32_t *checksum);
105
106static int
107ebs_write(service_id_t service_id, exfat_cfg_t *cfg,
108 int base, uint32_t *chksum);
109
110static int
111bitmap_write(service_id_t service_id, exfat_cfg_t *cfg);
112
113static void usage(void)
114{
115 printf("Usage: mkexfat <device>\n");
116}
117
118/** Initialize the exFAT params structure.
119 *
120 * @param cfg Pointer to the exFAT params structure to initialize.
121 */
122static void
123cfg_params_initialize(exfat_cfg_t *cfg)
124{
125 unsigned long fat_bytes;
126 aoff64_t const volume_bytes = (cfg->volume_count - FAT_SECTOR_START) *
127 cfg->sector_size;
128
129 aoff64_t n_req_clusters = volume_bytes / DEFAULT_CLUSTER_SIZE;
130 cfg->cluster_size = DEFAULT_CLUSTER_SIZE;
131
132 /* Compute the required cluster size to index
133 * the entire storage device and to keep the FAT
134 * size less or equal to 64 Mb.
135 */
136 while (n_req_clusters > 16000000ULL &&
137 (cfg->cluster_size < 32 * 1024 * 1024)) {
138
139 cfg->cluster_size <<= 1;
140 n_req_clusters = volume_bytes / cfg->cluster_size;
141 }
142
143 /* The first two clusters are reserved */
144 cfg->total_clusters = n_req_clusters + 2;
145
146 /* Compute the FAT size in sectors */
147 fat_bytes = (cfg->total_clusters + 1) * 4;
148 cfg->fat_sector_count = div_round_up(fat_bytes, cfg->sector_size);
149
150 /* Compute the number of the first data sector */
151 cfg->data_start_sector = ROUND_UP(FAT_SECTOR_START +
152 cfg->fat_sector_count, cfg->cluster_size / cfg->sector_size);
153
154 /* Compute the bitmap size */
155 cfg->bitmap_size = n_req_clusters / 8;
156
157 /* Compute the number of clusters reserved to the bitmap */
158 cfg->allocated_clusters = div_round_up(cfg->bitmap_size,
159 cfg->cluster_size);
160
161 /* This account for the root directory */
162 cfg->allocated_clusters++;
163
164 /* Compute the number of clusters reserved to the upcase table */
165 cfg->allocated_clusters += div_round_up(sizeof(upcase_table),
166 cfg->cluster_size);
167
168 /* Will be set later */
169 cfg->rootdir_cluster = 0;
170
171 /* The first sector of the partition is zero */
172 cfg->volume_start = 0;
173}
174
175/** Prints the exFAT structure values
176 *
177 * @param cfg Pointer to the exfat_cfg_t structure.
178 */
179static void
180cfg_print_info(exfat_cfg_t *cfg)
181{
182 printf(NAME ": Sector size: %lu\n", cfg->sector_size);
183 printf(NAME ": Cluster size: %lu\n", cfg->cluster_size);
184 printf(NAME ": FAT size in sectors: %lu\n", cfg->fat_sector_count);
185 printf(NAME ": Data start sector: %lu\n", cfg->data_start_sector);
186 printf(NAME ": Total num of clusters: %lu\n", cfg->total_clusters);
187 printf(NAME ": Bitmap size: %lu\n",
188 div_round_up(cfg->bitmap_size, cfg->cluster_size));
189 printf(NAME ": Upcase table size: %lu\n",
190 div_round_up(sizeof(upcase_table), cfg->cluster_size));
191}
192
193/** Initialize the Main Boot Sector fields.
194 *
195 * @param mbs Pointer to the Main Boot Sector structure.
196 * @param cfg Pointer to the exFAT configuration structure.
197 * @return Initial checksum value.
198 */
199static uint32_t
200vbr_initialize(exfat_bs_t *mbs, exfat_cfg_t *cfg)
201{
202 /* Fill the structure with zeroes */
203 memset(mbs, 0, sizeof(exfat_bs_t));
204
205 /* Init Jump Boot section */
206 mbs->jump[0] = 0xEB;
207 mbs->jump[1] = 0x76;
208 mbs->jump[2] = 0x90;
209
210 /* Set the filesystem name */
211 memcpy(mbs->oem_name, "EXFAT ", sizeof(mbs->oem_name));
212
213 mbs->volume_start = host2uint64_t_le(cfg->volume_start);
214 mbs->volume_count = host2uint64_t_le(cfg->volume_count);
215 mbs->fat_sector_start = host2uint32_t_le(FAT_SECTOR_START);
216 mbs->fat_sector_count = host2uint32_t_le(cfg->fat_sector_count);
217 mbs->data_start_sector = host2uint32_t_le(cfg->data_start_sector);
218
219 mbs->data_clusters = host2uint32_t_le(cfg->total_clusters -
220 div_round_up(cfg->data_start_sector, cfg->cluster_size));
221
222 mbs->rootdir_cluster = host2uint32_t_le(cfg->rootdir_cluster);
223 mbs->volume_serial = 0;
224 mbs->version.major = 1;
225 mbs->version.minor = 0;
226 mbs->volume_flags = host2uint16_t_le(0);
227 mbs->bytes_per_sector = log2(cfg->sector_size);
228 mbs->sec_per_cluster = log2(cfg->cluster_size / cfg->sector_size);
229
230 /* Maximum cluster size is 32 Mb */
231 assert((mbs->bytes_per_sector + mbs->sec_per_cluster) <= 25);
232
233 mbs->fat_count = 1;
234 mbs->drive_no = 0x80;
235 mbs->allocated_percent = 0;
236 mbs->signature = host2uint16_t_le(0xAA55);
237
238 return vbr_checksum_start(mbs, sizeof(exfat_bs_t));
239}
240
241static int
242bootsec_write(service_id_t service_id, exfat_cfg_t *cfg)
243{
244 exfat_bs_t mbs;
245 uint32_t vbr_checksum;
246 uint32_t initial_checksum;
247 int rc;
248
249 vbr_checksum = vbr_initialize(&mbs, cfg);
250 initial_checksum = vbr_checksum;
251
252 /* Write the Main Boot Sector to disk */
253 rc = block_write_direct(service_id, MBS_SECTOR, 1, &mbs);
254 if (rc != EOK)
255 return rc;
256
257 /* Write the Main extended boot sectors to disk */
258 rc = ebs_write(service_id, cfg, EBS_SECTOR_START, &vbr_checksum);
259 if (rc != EOK)
260 return rc;
261
262 /* Write the Main Boot Sector backup to disk */
263 rc = block_write_direct(service_id, MBS_BACKUP_SECTOR, 1, &mbs);
264 if (rc != EOK)
265 return rc;
266
267 /* Restore the checksum to its initial value */
268 vbr_checksum = initial_checksum;
269
270 /* Write the Main extended boot sectors backup to disk */
271 return ebs_write(service_id, cfg,
272 EBS_BACKUP_SECTOR_START, &vbr_checksum);
273}
274
275/** Write the Main Extended Boot Sector to disk
276 *
277 * @param service_id The service id.
278 * @param cfg Pointer to the exFAT configuration structure.
279 * @param base Base sector of the EBS.
280 * @return EOK on success or a negative error code.
281 */
282static int
283ebs_write(service_id_t service_id, exfat_cfg_t *cfg, int base, uint32_t *chksum)
284{
285 uint32_t *ebs = calloc(cfg->sector_size, sizeof(uint8_t));
286 int i, rc;
287 unsigned idx;
288
289 if (!ebs)
290 return ENOMEM;
291
292 ebs[cfg->sector_size / 4 - 1] = host2uint32_t_le(0xAA550000);
293
294 for (i = 0; i < EBS_SIZE; ++i) {
295 vbr_checksum_update(ebs, cfg->sector_size, chksum);
296
297 rc = block_write_direct(service_id,
298 i + EBS_SECTOR_START + base, 1, ebs);
299
300 if (rc != EOK)
301 goto exit;
302 }
303
304 /* The OEM record is not yet used
305 * by the official exFAT implementation, we'll fill
306 * it with zeroes.
307 */
308
309 memset(ebs, 0, cfg->sector_size);
310 vbr_checksum_update(ebs, cfg->sector_size, chksum);
311
312 rc = block_write_direct(service_id, i++ + base, 1, ebs);
313 if (rc != EOK)
314 goto exit;
315
316 /* The next sector is reserved, fill it with zeroes too */
317 vbr_checksum_update(ebs, cfg->sector_size, chksum);
318 rc = block_write_direct(service_id, i++ + base, 1, ebs);
319 if (rc != EOK)
320 goto exit;
321
322 /* Write the checksum sector */
323 for (idx = 0; idx < cfg->sector_size / sizeof(uint32_t); ++idx)
324 ebs[idx] = host2uint32_t_le(*chksum);
325
326 rc = block_write_direct(service_id, i + base, 1, ebs);
327
328exit:
329 free(ebs);
330 return rc;
331}
332
333/** Initialize the FAT table.
334 *
335 * @param service_id The service id.
336 * @param cfg Pointer to the exfat_cfg structure.
337 * @return EOK on success or a negative error code.
338 */
339static int
340fat_initialize(service_id_t service_id, exfat_cfg_t *cfg)
341{
342 unsigned long i;
343 uint32_t *pfat;
344 int rc;
345
346 pfat = calloc(cfg->sector_size, 1);
347 if (!pfat)
348 return ENOMEM;
349
350 pfat[0] = host2uint32_t_le(0xFFFFFFF8);
351 pfat[1] = host2uint32_t_le(0xFFFFFFFF);
352
353 rc = block_write_direct(service_id, FAT_SECTOR_START, 1, pfat);
354 if (rc != EOK)
355 goto error;
356
357 pfat[0] = pfat[1] = 0;
358
359 for (i = 1; i < cfg->fat_sector_count; ++i) {
360 rc = block_write_direct(service_id,
361 FAT_SECTOR_START + i, 1, pfat);
362 if (rc != EOK)
363 goto error;
364 }
365
366error:
367 free(pfat);
368 return rc;
369}
370
371/** Allocate a given number of clusters and create a cluster chain.
372 *
373 * @param service_id The service id.
374 * @param cfg Pointer to the exfat configuration number.
375 * @param cur_cls Cluster index from where to start the allocation.
376 * @param ncls Number of clusters to allocate.
377 * @return EOK on success or a negative error code.
378 */
379static int
380fat_allocate_clusters(service_id_t service_id, exfat_cfg_t *cfg,
381 uint32_t cur_cls, unsigned long ncls)
382{
383 int rc;
384 unsigned const fat_entries = cfg->sector_size / sizeof(uint32_t);
385 aoff64_t fat_sec = cur_cls / fat_entries + FAT_SECTOR_START;
386 uint32_t *fat;
387
388 cur_cls %= fat_entries;
389
390 fat = malloc(cfg->sector_size);
391 if (!fat)
392 return ENOMEM;
393
394loop:
395 rc = block_read_direct(service_id, fat_sec, 1, fat);
396 if (rc != EOK)
397 goto exit;
398
399 assert(fat[cur_cls] == 0);
400 assert(ncls > 0);
401
402 for (; cur_cls < fat_entries && ncls > 1; ++cur_cls, --ncls)
403 fat[cur_cls] = host2uint32_t_le(cur_cls + 1);
404
405 if (cur_cls == fat_entries) {
406 /* This sector is full, there are no more free entries,
407 * read the next sector and restart the search.
408 */
409 rc = block_write_direct(service_id, fat_sec++, 1, fat);
410 if (rc != EOK)
411 goto exit;
412 cur_cls = 0;
413 goto loop;
414 } else if (ncls == 1) {
415 /* This is the last cluster of this chain, mark it
416 * with EOF.
417 */
418 fat[cur_cls] = host2uint32_t_le(0xFFFFFFFF);
419 }
420
421 rc = block_write_direct(service_id, fat_sec, 1, fat);
422
423exit:
424 free(fat);
425 return rc;
426}
427
428/** Initialize the allocation bitmap.
429 *
430 * @param service_id The service id.
431 * @param cfg Pointer to the exfat configuration structure.
432 * @return EOK on success or a negative error code.
433 */
434static int
435bitmap_write(service_id_t service_id, exfat_cfg_t *cfg)
436{
437 unsigned long i, sec;
438 unsigned long allocated_cls;
439 int rc = EOK;
440 bool need_reset = true;
441
442 /* Bitmap size in sectors */
443 size_t const bss = div_round_up(cfg->bitmap_size, cfg->sector_size);
444
445 uint8_t *bitmap = malloc(cfg->sector_size);
446 if (!bitmap)
447 return ENOMEM;
448
449 allocated_cls = cfg->allocated_clusters;
450
451 for (sec = 0; sec < bss; ++sec) {
452 if (need_reset) {
453 need_reset = false;
454 memset(bitmap, 0, cfg->sector_size);
455 }
456 if (allocated_cls > 0) {
457 for (i = 0; i < allocated_cls; ++i) {
458 unsigned byte_idx = i / 8;
459 unsigned bit_idx = i % 8;
460
461 if (byte_idx == cfg->sector_size)
462 break;
463 bitmap[byte_idx] |= 1 << bit_idx;
464 }
465
466 allocated_cls -= i;
467 need_reset = true;
468 }
469
470 rc = block_write_direct(service_id,
471 cfg->data_start_sector + sec, 1, bitmap);
472 if (rc != EOK)
473 goto exit;
474 }
475
476exit:
477 free(bitmap);
478 return rc;
479}
480
481/** Write the upcase table to disk. */
482static int
483upcase_table_write(service_id_t service_id, exfat_cfg_t *cfg)
484{
485 int rc = EOK;
486 aoff64_t start_sec, nsecs, i;
487 uint8_t *table_ptr;
488 uint8_t *buf;
489 size_t table_size = sizeof(upcase_table);
490
491 buf = malloc(cfg->sector_size);
492 if (!buf)
493 return ENOENT;
494
495 /* Compute the start sector of the upcase table */
496 start_sec = cfg->data_start_sector;
497 start_sec += ((cfg->upcase_table_cluster - 2) * cfg->cluster_size) /
498 cfg->sector_size;
499
500 /* Compute the number of sectors needed to store the table on disk */
501 nsecs = div_round_up(sizeof(upcase_table), cfg->sector_size);
502 table_ptr = (uint8_t *) upcase_table;
503
504 for (i = 0; i < nsecs; ++i,
505 table_ptr += min(table_size, cfg->sector_size),
506 table_size -= cfg->sector_size) {
507
508 if (table_size < cfg->sector_size) {
509 /* Reset the content of the unused part
510 * of the last sector.
511 */
512 memset(buf, 0, cfg->sector_size);
513 }
514 memcpy(buf, table_ptr, min(table_size, cfg->sector_size));
515
516 rc = block_write_direct(service_id,
517 start_sec + i, 1, buf);
518 if (rc != EOK)
519 break;
520 }
521
522 free(buf);
523 return rc;
524}
525
526/** Given a number (n), returns the result of log2(n).
527 *
528 * It works only if n is a power of two.
529 */
530static unsigned
531log2(unsigned n)
532{
533 unsigned r;
534
535 for (r = 0;n >> r != 1; ++r);
536
537 return r;
538}
539
540/** Initialize the VBR checksum calculation */
541static uint32_t
542vbr_checksum_start(void const *data, size_t nbytes)
543{
544 uint32_t checksum = 0;
545 size_t index;
546 uint8_t const *octets = (uint8_t *) data;
547
548 for (index = 0; index < nbytes; ++index) {
549 if (index == 106 || index == 107 || index == 112) {
550 /* Skip volume_flags and allocated_percent fields */
551 continue;
552 }
553
554 checksum = ((checksum << 31) | (checksum >> 1)) + octets[index];
555 }
556
557 return checksum;
558}
559
560/** Update the VBR checksum */
561static void
562vbr_checksum_update(void const *data, size_t nbytes, uint32_t *checksum)
563{
564 size_t index;
565 uint8_t const *octets = (uint8_t *) data;
566
567 for (index = 0; index < nbytes; ++index)
568 *checksum = ((*checksum << 31) | (*checksum >> 1)) + octets[index];
569}
570
571int main (int argc, char **argv)
572{
573 exfat_cfg_t cfg;
574 uint32_t next_cls;
575 char *dev_path;
576 service_id_t service_id;
577 int rc;
578
579 if (argc < 2) {
580 printf(NAME ": Error, argument missing\n");
581 usage();
582 return 1;
583 }
584
585 /* TODO: Add parameters */
586
587 ++argv;
588 dev_path = *argv;
589
590 printf(NAME ": Device = %s\n", dev_path);
591
592 rc = loc_service_get_id(dev_path, &service_id, 0);
593 if (rc != EOK) {
594 printf(NAME ": Error resolving device `%s'.\n", dev_path);
595 return 2;
596 }
597
598 rc = block_init(EXCHANGE_SERIALIZE, service_id, 2048);
599 if (rc != EOK) {
600 printf(NAME ": Error initializing libblock.\n");
601 return 2;
602 }
603
604 rc = block_get_bsize(service_id, &cfg.sector_size);
605 if (rc != EOK) {
606 printf(NAME ": Error determining device block size.\n");
607 return 2;
608 }
609
610 if (cfg.sector_size > 4096) {
611 printf(NAME ": Error, sector size can't be greater" \
612 " than 4096 bytes.\n");
613 return 2;
614 }
615
616 rc = block_get_nblocks(service_id, &cfg.volume_count);
617 if (rc != EOK) {
618 printf(NAME ": Warning, failed to obtain" \
619 " device block size.\n");
620 /* FIXME: the user should be able to specify the filesystem size */
621 return 1;
622 } else {
623 printf(NAME ": Block device has %" PRIuOFF64 " blocks.\n",
624 cfg.volume_count);
625 }
626
627 cfg_params_initialize(&cfg);
628 cfg_print_info(&cfg);
629
630 /* Initialize the FAT table */
631 rc = fat_initialize(service_id, &cfg);
632 if (rc != EOK) {
633 printf(NAME ": Error, failed to write the FAT to disk\n");
634 return 2;
635 }
636
637 /* Allocate clusters for the bitmap */
638 rc = fat_allocate_clusters(service_id, &cfg, FIRST_FREE_CLUSTER,
639 div_round_up(cfg.bitmap_size, cfg.cluster_size));
640 if (rc != EOK) {
641 printf(NAME ": Error, failed to allocate clusters for bitmap.\n");
642 return 2;
643 }
644
645 next_cls = FIRST_FREE_CLUSTER +
646 div_round_up(cfg.bitmap_size, cfg.cluster_size);
647 cfg.upcase_table_cluster = next_cls;
648
649 /* Allocate clusters for the upcase table */
650 rc = fat_allocate_clusters(service_id, &cfg, next_cls,
651 div_round_up(sizeof(upcase_table), cfg.cluster_size));
652 if (rc != EOK) {
653 printf(NAME ":Error, failed to allocate clusters foe the upcase table.\n");
654 return 2;
655 }
656
657 next_cls += div_round_up(sizeof(upcase_table), cfg.cluster_size);
658 cfg.rootdir_cluster = next_cls;
659
660 /* Allocate a cluster for the root directory entry */
661 rc = fat_allocate_clusters(service_id, &cfg, next_cls, 1);
662 if (rc != EOK) {
663 printf(NAME ": Error, failed to allocate cluster for the root dentry.\n");
664 return 2;
665 }
666
667 /* Write the allocation bitmap to disk */
668 rc = bitmap_write(service_id, &cfg);
669 if (rc != EOK) {
670 printf(NAME ": Error, failed to write the allocation" \
671 " bitmap to disk.\n");
672 return 2;
673 }
674
675 /* Write the upcase table to disk */
676 rc = upcase_table_write(service_id, &cfg);
677 if (rc != EOK) {
678 printf(NAME ": Error, failed to write the upcase table to disk.\n");
679 return 2;
680 }
681
682 rc = bootsec_write(service_id, &cfg);
683 if (rc != EOK) {
684 printf(NAME ": Error, failed to write the VBR to disk\n");
685 return 2;
686 }
687
688 return 0;
689}
690
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