1 // SPDX-License-Identifier: GPL-2.0+
5 * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
7 * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
8 * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
17 #include <asm/byteorder.h>
21 #include <linux/compiler.h>
22 #include <linux/ctype.h>
25 * Convert a string to lowercase. Converts at most 'len' characters,
26 * 'len' may be larger than the length of 'str' if 'str' is NULL
29 static void downcase(char *str
, size_t len
)
31 while (*str
!= '\0' && len
--) {
37 static struct blk_desc
*cur_dev
;
38 static disk_partition_t cur_part_info
;
40 #define DOS_BOOT_MAGIC_OFFSET 0x1fe
41 #define DOS_FS_TYPE_OFFSET 0x36
42 #define DOS_FS32_TYPE_OFFSET 0x52
44 static int disk_read(__u32 block
, __u32 nr_blocks
, void *buf
)
51 ret
= blk_dread(cur_dev
, cur_part_info
.start
+ block
, nr_blocks
, buf
);
59 int fat_set_blk_dev(struct blk_desc
*dev_desc
, disk_partition_t
*info
)
61 ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer
, dev_desc
->blksz
);
64 cur_part_info
= *info
;
66 /* Make sure it has a valid FAT header */
67 if (disk_read(0, 1, buffer
) != 1) {
72 /* Check if it's actually a DOS volume */
73 if (memcmp(buffer
+ DOS_BOOT_MAGIC_OFFSET
, "\x55\xAA", 2)) {
78 /* Check for FAT12/FAT16/FAT32 filesystem */
79 if (!memcmp(buffer
+ DOS_FS_TYPE_OFFSET
, "FAT", 3))
81 if (!memcmp(buffer
+ DOS_FS32_TYPE_OFFSET
, "FAT32", 5))
88 int fat_register_device(struct blk_desc
*dev_desc
, int part_no
)
90 disk_partition_t info
;
92 /* First close any currently found FAT filesystem */
95 /* Read the partition table, if present */
96 if (part_get_info(dev_desc
, part_no
, &info
)) {
98 printf("** Partition %d not valid on device %d **\n",
99 part_no
, dev_desc
->devnum
);
104 info
.size
= dev_desc
->lba
;
105 info
.blksz
= dev_desc
->blksz
;
109 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
114 return fat_set_blk_dev(dev_desc
, &info
);
118 * Extract zero terminated short name from a directory entry.
120 static void get_name(dir_entry
*dirent
, char *s_name
)
124 memcpy(s_name
, dirent
->name
, 8);
127 while (*ptr
&& *ptr
!= ' ')
129 if (dirent
->lcase
& CASE_LOWER_BASE
)
130 downcase(s_name
, (unsigned)(ptr
- s_name
));
131 if (dirent
->ext
[0] && dirent
->ext
[0] != ' ') {
133 memcpy(ptr
, dirent
->ext
, 3);
134 if (dirent
->lcase
& CASE_LOWER_EXT
)
137 while (*ptr
&& *ptr
!= ' ')
141 if (*s_name
== DELETED_FLAG
)
143 else if (*s_name
== aRING
)
144 *s_name
= DELETED_FLAG
;
147 static int flush_dirty_fat_buffer(fsdata
*mydata
);
149 #if !CONFIG_IS_ENABLED(FAT_WRITE)
150 /* Stub for read only operation */
151 int flush_dirty_fat_buffer(fsdata
*mydata
)
159 * Get the entry at index 'entry' in a FAT (12/16/32) table.
160 * On failure 0x00 is returned.
162 static __u32
get_fatent(fsdata
*mydata
, __u32 entry
)
168 if (CHECK_CLUST(entry
, mydata
->fatsize
)) {
169 printf("Error: Invalid FAT entry: 0x%08x\n", entry
);
173 switch (mydata
->fatsize
) {
175 bufnum
= entry
/ FAT32BUFSIZE
;
176 offset
= entry
- bufnum
* FAT32BUFSIZE
;
179 bufnum
= entry
/ FAT16BUFSIZE
;
180 offset
= entry
- bufnum
* FAT16BUFSIZE
;
183 bufnum
= entry
/ FAT12BUFSIZE
;
184 offset
= entry
- bufnum
* FAT12BUFSIZE
;
188 /* Unsupported FAT size */
192 debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
193 mydata
->fatsize
, entry
, entry
, offset
, offset
);
195 /* Read a new block of FAT entries into the cache. */
196 if (bufnum
!= mydata
->fatbufnum
) {
197 __u32 getsize
= FATBUFBLOCKS
;
198 __u8
*bufptr
= mydata
->fatbuf
;
199 __u32 fatlength
= mydata
->fatlength
;
200 __u32 startblock
= bufnum
* FATBUFBLOCKS
;
202 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
203 if (startblock
+ getsize
> fatlength
)
204 getsize
= fatlength
- startblock
;
206 startblock
+= mydata
->fat_sect
; /* Offset from start of disk */
208 /* Write back the fatbuf to the disk */
209 if (flush_dirty_fat_buffer(mydata
) < 0)
212 if (disk_read(startblock
, getsize
, bufptr
) < 0) {
213 debug("Error reading FAT blocks\n");
216 mydata
->fatbufnum
= bufnum
;
219 /* Get the actual entry from the table */
220 switch (mydata
->fatsize
) {
222 ret
= FAT2CPU32(((__u32
*) mydata
->fatbuf
)[offset
]);
225 ret
= FAT2CPU16(((__u16
*) mydata
->fatbuf
)[offset
]);
228 off8
= (offset
* 3) / 2;
229 /* fatbut + off8 may be unaligned, read in byte granularity */
230 ret
= mydata
->fatbuf
[off8
] + (mydata
->fatbuf
[off8
+ 1] << 8);
236 debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
237 mydata
->fatsize
, ret
, entry
, offset
);
243 * Read at most 'size' bytes from the specified cluster into 'buffer'.
244 * Return 0 on success, -1 otherwise.
247 get_cluster(fsdata
*mydata
, __u32 clustnum
, __u8
*buffer
, unsigned long size
)
254 startsect
= clust_to_sect(mydata
, clustnum
);
256 startsect
= mydata
->rootdir_sect
;
259 debug("gc - clustnum: %d, startsect: %d\n", clustnum
, startsect
);
261 if ((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1)) {
262 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
264 debug("FAT: Misaligned buffer address (%p)\n", buffer
);
266 while (size
>= mydata
->sect_size
) {
267 ret
= disk_read(startsect
++, 1, tmpbuf
);
269 debug("Error reading data (got %d)\n", ret
);
273 memcpy(buffer
, tmpbuf
, mydata
->sect_size
);
274 buffer
+= mydata
->sect_size
;
275 size
-= mydata
->sect_size
;
278 idx
= size
/ mydata
->sect_size
;
279 ret
= disk_read(startsect
, idx
, buffer
);
281 debug("Error reading data (got %d)\n", ret
);
285 idx
*= mydata
->sect_size
;
290 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
292 ret
= disk_read(startsect
, 1, tmpbuf
);
294 debug("Error reading data (got %d)\n", ret
);
298 memcpy(buffer
, tmpbuf
, size
);
305 * get_contents() - read from file
307 * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
308 * into 'buffer'. Update the number of bytes read in *gotsize or return -1 on
311 * @mydata: file system description
312 * @dentprt: directory entry pointer
313 * @pos: position from where to read
314 * @buffer: buffer into which to read
315 * @maxsize: maximum number of bytes to read
316 * @gotsize: number of bytes actually read
317 * Return: -1 on error, otherwise 0
319 static int get_contents(fsdata
*mydata
, dir_entry
*dentptr
, loff_t pos
,
320 __u8
*buffer
, loff_t maxsize
, loff_t
*gotsize
)
322 loff_t filesize
= FAT2CPU32(dentptr
->size
);
323 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
324 __u32 curclust
= START(dentptr
);
325 __u32 endclust
, newclust
;
329 debug("Filesize: %llu bytes\n", filesize
);
331 if (pos
>= filesize
) {
332 debug("Read position past EOF: %llu\n", pos
);
336 if (maxsize
> 0 && filesize
> pos
+ maxsize
)
337 filesize
= pos
+ maxsize
;
339 debug("%llu bytes\n", filesize
);
341 actsize
= bytesperclust
;
343 /* go to cluster at pos */
344 while (actsize
<= pos
) {
345 curclust
= get_fatent(mydata
, curclust
);
346 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
347 debug("curclust: 0x%x\n", curclust
);
348 printf("Invalid FAT entry\n");
351 actsize
+= bytesperclust
;
355 actsize
-= bytesperclust
;
359 /* align to beginning of next cluster if any */
363 actsize
= min(filesize
, (loff_t
)bytesperclust
);
364 tmp_buffer
= malloc_cache_aligned(actsize
);
366 debug("Error: allocating buffer\n");
370 if (get_cluster(mydata
, curclust
, tmp_buffer
, actsize
) != 0) {
371 printf("Error reading cluster\n");
377 memcpy(buffer
, tmp_buffer
+ pos
, actsize
);
384 curclust
= get_fatent(mydata
, curclust
);
385 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
386 debug("curclust: 0x%x\n", curclust
);
387 printf("Invalid FAT entry\n");
392 actsize
= bytesperclust
;
396 /* search for consecutive clusters */
397 while (actsize
< filesize
) {
398 newclust
= get_fatent(mydata
, endclust
);
399 if ((newclust
- 1) != endclust
)
401 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
402 debug("curclust: 0x%x\n", newclust
);
403 printf("Invalid FAT entry\n");
407 actsize
+= bytesperclust
;
410 /* get remaining bytes */
412 if (get_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
413 printf("Error reading cluster\n");
419 if (get_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
420 printf("Error reading cluster\n");
423 *gotsize
+= (int)actsize
;
427 curclust
= get_fatent(mydata
, endclust
);
428 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
429 debug("curclust: 0x%x\n", curclust
);
430 printf("Invalid FAT entry\n");
433 actsize
= bytesperclust
;
439 * Extract the file name information from 'slotptr' into 'l_name',
440 * starting at l_name[*idx].
441 * Return 1 if terminator (zero byte) is found, 0 otherwise.
443 static int slot2str(dir_slot
*slotptr
, char *l_name
, int *idx
)
447 for (j
= 0; j
<= 8; j
+= 2) {
448 l_name
[*idx
] = slotptr
->name0_4
[j
];
449 if (l_name
[*idx
] == 0x00)
453 for (j
= 0; j
<= 10; j
+= 2) {
454 l_name
[*idx
] = slotptr
->name5_10
[j
];
455 if (l_name
[*idx
] == 0x00)
459 for (j
= 0; j
<= 2; j
+= 2) {
460 l_name
[*idx
] = slotptr
->name11_12
[j
];
461 if (l_name
[*idx
] == 0x00)
469 /* Calculate short name checksum */
470 static __u8
mkcksum(const char name
[8], const char ext
[3])
476 for (i
= 0; i
< 8; i
++)
477 ret
= (((ret
& 1) << 7) | ((ret
& 0xfe) >> 1)) + name
[i
];
478 for (i
= 0; i
< 3; i
++)
479 ret
= (((ret
& 1) << 7) | ((ret
& 0xfe) >> 1)) + ext
[i
];
485 * Read boot sector and volume info from a FAT filesystem
488 read_bootsectandvi(boot_sector
*bs
, volume_info
*volinfo
, int *fatsize
)
491 volume_info
*vistart
;
494 if (cur_dev
== NULL
) {
495 debug("Error: no device selected\n");
499 block
= malloc_cache_aligned(cur_dev
->blksz
);
501 debug("Error: allocating block\n");
505 if (disk_read(0, 1, block
) < 0) {
506 debug("Error: reading block\n");
510 memcpy(bs
, block
, sizeof(boot_sector
));
511 bs
->reserved
= FAT2CPU16(bs
->reserved
);
512 bs
->fat_length
= FAT2CPU16(bs
->fat_length
);
513 bs
->secs_track
= FAT2CPU16(bs
->secs_track
);
514 bs
->heads
= FAT2CPU16(bs
->heads
);
515 bs
->total_sect
= FAT2CPU32(bs
->total_sect
);
518 if (bs
->fat_length
== 0) {
520 bs
->fat32_length
= FAT2CPU32(bs
->fat32_length
);
521 bs
->flags
= FAT2CPU16(bs
->flags
);
522 bs
->root_cluster
= FAT2CPU32(bs
->root_cluster
);
523 bs
->info_sector
= FAT2CPU16(bs
->info_sector
);
524 bs
->backup_boot
= FAT2CPU16(bs
->backup_boot
);
525 vistart
= (volume_info
*)(block
+ sizeof(boot_sector
));
528 vistart
= (volume_info
*)&(bs
->fat32_length
);
531 memcpy(volinfo
, vistart
, sizeof(volume_info
));
533 if (*fatsize
== 32) {
534 if (strncmp(FAT32_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0)
537 if (strncmp(FAT12_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0) {
541 if (strncmp(FAT16_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0) {
547 debug("Error: broken fs_type sign\n");
555 static int get_fs_info(fsdata
*mydata
)
561 ret
= read_bootsectandvi(&bs
, &volinfo
, &mydata
->fatsize
);
563 debug("Error: reading boot sector\n");
567 if (mydata
->fatsize
== 32) {
568 mydata
->fatlength
= bs
.fat32_length
;
569 mydata
->total_sect
= bs
.total_sect
;
571 mydata
->fatlength
= bs
.fat_length
;
572 mydata
->total_sect
= (bs
.sectors
[1] << 8) + bs
.sectors
[0];
573 if (!mydata
->total_sect
)
574 mydata
->total_sect
= bs
.total_sect
;
576 if (!mydata
->total_sect
) /* unlikely */
577 mydata
->total_sect
= (u32
)cur_part_info
.size
;
579 mydata
->fats
= bs
.fats
;
580 mydata
->fat_sect
= bs
.reserved
;
582 mydata
->rootdir_sect
= mydata
->fat_sect
+ mydata
->fatlength
* bs
.fats
;
584 mydata
->sect_size
= (bs
.sector_size
[1] << 8) + bs
.sector_size
[0];
585 mydata
->clust_size
= bs
.cluster_size
;
586 if (mydata
->sect_size
!= cur_part_info
.blksz
) {
587 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
588 mydata
->sect_size
, cur_part_info
.blksz
);
591 if (mydata
->clust_size
== 0) {
592 printf("Error: FAT cluster size not set\n");
595 if ((unsigned int)mydata
->clust_size
* mydata
->sect_size
>
597 printf("Error: FAT cluster size too big (cs=%u, max=%u)\n",
598 (unsigned int)mydata
->clust_size
* mydata
->sect_size
,
603 if (mydata
->fatsize
== 32) {
604 mydata
->data_begin
= mydata
->rootdir_sect
-
605 (mydata
->clust_size
* 2);
606 mydata
->root_cluster
= bs
.root_cluster
;
608 mydata
->rootdir_size
= ((bs
.dir_entries
[1] * (int)256 +
612 mydata
->data_begin
= mydata
->rootdir_sect
+
613 mydata
->rootdir_size
-
614 (mydata
->clust_size
* 2);
617 * The root directory is not cluster-aligned and may be on a
618 * "negative" cluster, this will be handled specially in
621 mydata
->root_cluster
= 0;
624 mydata
->fatbufnum
= -1;
625 mydata
->fat_dirty
= 0;
626 mydata
->fatbuf
= malloc_cache_aligned(FATBUFSIZE
);
627 if (mydata
->fatbuf
== NULL
) {
628 debug("Error: allocating memory\n");
632 debug("FAT%d, fat_sect: %d, fatlength: %d\n",
633 mydata
->fatsize
, mydata
->fat_sect
, mydata
->fatlength
);
634 debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
635 "Data begins at: %d\n",
636 mydata
->root_cluster
,
637 mydata
->rootdir_sect
,
638 mydata
->rootdir_sect
* mydata
->sect_size
, mydata
->data_begin
);
639 debug("Sector size: %d, cluster size: %d\n", mydata
->sect_size
,
647 * Directory iterator, to simplify filesystem traversal
649 * Implements an iterator pattern to traverse directory tables,
650 * transparently handling directory tables split across multiple
651 * clusters, and the difference between FAT12/FAT16 root directory
652 * (contiguous) and subdirectories + FAT32 root (chained).
656 * for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) {
657 * // to traverse down to a subdirectory pointed to by
658 * // current iterator position:
659 * fat_itr_child(&itr, &itr);
662 * For more complete example, see fat_itr_resolve()
666 fsdata
*fsdata
; /* filesystem parameters */
667 unsigned start_clust
; /* first cluster */
668 unsigned clust
; /* current cluster */
669 unsigned next_clust
; /* next cluster if remaining == 0 */
670 int last_cluster
; /* set once we've read last cluster */
671 int is_root
; /* is iterator at root directory */
672 int remaining
; /* remaining dent's in current cluster */
674 /* current iterator position values: */
675 dir_entry
*dent
; /* current directory entry */
676 char l_name
[VFAT_MAXLEN_BYTES
]; /* long (vfat) name */
677 char s_name
[14]; /* short 8.3 name */
678 char *name
; /* l_name if there is one, else s_name */
680 /* storage for current cluster in memory: */
681 u8 block
[MAX_CLUSTSIZE
] __aligned(ARCH_DMA_MINALIGN
);
684 static int fat_itr_isdir(fat_itr
*itr
);
687 * fat_itr_root() - initialize an iterator to start at the root
690 * @itr: iterator to initialize
691 * @fsdata: filesystem data for the partition
692 * @return 0 on success, else -errno
694 static int fat_itr_root(fat_itr
*itr
, fsdata
*fsdata
)
696 if (get_fs_info(fsdata
))
699 itr
->fsdata
= fsdata
;
700 itr
->start_clust
= 0;
701 itr
->clust
= fsdata
->root_cluster
;
702 itr
->next_clust
= fsdata
->root_cluster
;
705 itr
->last_cluster
= 0;
712 * fat_itr_child() - initialize an iterator to descend into a sub-
715 * Initializes 'itr' to iterate the contents of the directory at
716 * the current cursor position of 'parent'. It is an error to
717 * call this if the current cursor of 'parent' is pointing at a
720 * Note that 'itr' and 'parent' can be the same pointer if you do
721 * not need to preserve 'parent' after this call, which is useful
722 * for traversing directory structure to resolve a file/directory.
724 * @itr: iterator to initialize
725 * @parent: the iterator pointing at a directory entry in the
726 * parent directory of the directory to iterate
728 static void fat_itr_child(fat_itr
*itr
, fat_itr
*parent
)
730 fsdata
*mydata
= parent
->fsdata
; /* for silly macros */
731 unsigned clustnum
= START(parent
->dent
);
733 assert(fat_itr_isdir(parent
));
735 itr
->fsdata
= parent
->fsdata
;
736 itr
->start_clust
= clustnum
;
738 itr
->clust
= clustnum
;
739 itr
->next_clust
= clustnum
;
742 itr
->clust
= parent
->fsdata
->root_cluster
;
743 itr
->next_clust
= parent
->fsdata
->root_cluster
;
748 itr
->last_cluster
= 0;
751 static void *next_cluster(fat_itr
*itr
, unsigned *nbytes
)
753 fsdata
*mydata
= itr
->fsdata
; /* for silly macros */
758 /* have we reached the end? */
759 if (itr
->last_cluster
)
762 if (itr
->is_root
&& itr
->fsdata
->fatsize
!= 32) {
764 * The root directory is located before the data area and
765 * cannot be indexed using the regular unsigned cluster
766 * numbers (it may start at a "negative" cluster or not at a
767 * cluster boundary at all), so consider itr->next_clust to be
768 * a offset in cluster-sized units from the start of rootdir.
770 unsigned sect_offset
= itr
->next_clust
* itr
->fsdata
->clust_size
;
771 unsigned remaining_sects
= itr
->fsdata
->rootdir_size
- sect_offset
;
772 sect
= itr
->fsdata
->rootdir_sect
+ sect_offset
;
773 /* do not read past the end of rootdir */
774 read_size
= min_t(u32
, itr
->fsdata
->clust_size
,
777 sect
= clust_to_sect(itr
->fsdata
, itr
->next_clust
);
778 read_size
= itr
->fsdata
->clust_size
;
781 debug("FAT read(sect=%d), clust_size=%d, read_size=%u, DIRENTSPERBLOCK=%zd\n",
782 sect
, itr
->fsdata
->clust_size
, read_size
, DIRENTSPERBLOCK
);
785 * NOTE: do_fat_read_at() had complicated logic to deal w/
786 * vfat names that span multiple clusters in the fat16 case,
787 * which get_dentfromdir() probably also needed (and was
788 * missing). And not entirely sure what fat32 didn't have
789 * the same issue.. We solve that by only caring about one
790 * dent at a time and iteratively constructing the vfat long
793 ret
= disk_read(sect
, read_size
, itr
->block
);
795 debug("Error: reading block\n");
799 *nbytes
= read_size
* itr
->fsdata
->sect_size
;
800 itr
->clust
= itr
->next_clust
;
801 if (itr
->is_root
&& itr
->fsdata
->fatsize
!= 32) {
803 if (itr
->next_clust
* itr
->fsdata
->clust_size
>=
804 itr
->fsdata
->rootdir_size
) {
805 debug("nextclust: 0x%x\n", itr
->next_clust
);
806 itr
->last_cluster
= 1;
809 itr
->next_clust
= get_fatent(itr
->fsdata
, itr
->next_clust
);
810 if (CHECK_CLUST(itr
->next_clust
, itr
->fsdata
->fatsize
)) {
811 debug("nextclust: 0x%x\n", itr
->next_clust
);
812 itr
->last_cluster
= 1;
819 static dir_entry
*next_dent(fat_itr
*itr
)
821 if (itr
->remaining
== 0) {
823 struct dir_entry
*dent
= next_cluster(itr
, &nbytes
);
825 /* have we reached the last cluster? */
827 /* a sign for no more entries left */
832 itr
->remaining
= nbytes
/ sizeof(dir_entry
) - 1;
839 /* have we reached the last valid entry? */
840 if (itr
->dent
->name
[0] == 0)
846 static dir_entry
*extract_vfat_name(fat_itr
*itr
)
848 struct dir_entry
*dent
= itr
->dent
;
849 int seqn
= itr
->dent
->name
[0] & ~LAST_LONG_ENTRY_MASK
;
850 u8 chksum
, alias_checksum
= ((dir_slot
*)dent
)->alias_checksum
;
857 slot2str((dir_slot
*)dent
, buf
, &idx
);
859 if (n
+ idx
>= sizeof(itr
->l_name
))
862 /* shift accumulated long-name up and copy new part in: */
863 memmove(itr
->l_name
+ idx
, itr
->l_name
, n
);
864 memcpy(itr
->l_name
, buf
, idx
);
867 dent
= next_dent(itr
);
873 * We are now at the short file name entry.
874 * If it is marked as deleted, just skip it.
876 if (dent
->name
[0] == DELETED_FLAG
||
877 dent
->name
[0] == aRING
)
880 itr
->l_name
[n
] = '\0';
882 chksum
= mkcksum(dent
->name
, dent
->ext
);
884 /* checksum mismatch could mean deleted file, etc.. skip it: */
885 if (chksum
!= alias_checksum
) {
886 debug("** chksum=%x, alias_checksum=%x, l_name=%s, s_name=%8s.%3s\n",
887 chksum
, alias_checksum
, itr
->l_name
, dent
->name
, dent
->ext
);
895 * fat_itr_next() - step to the next entry in a directory
897 * Must be called once on a new iterator before the cursor is valid.
899 * @itr: the iterator to iterate
900 * @return boolean, 1 if success or 0 if no more entries in the
903 static int fat_itr_next(fat_itr
*itr
)
910 * One logical directory entry consist of following slots:
912 * dent[N - N]: LFN[N - 1] N|0x40 ATTR_VFAT
914 * dent[N - 2]: LFN[1] 2 ATTR_VFAT
915 * dent[N - 1]: LFN[0] 1 ATTR_VFAT
916 * dent[N]: SFN ATTR_ARCH
920 dent
= next_dent(itr
);
924 if (dent
->name
[0] == DELETED_FLAG
||
925 dent
->name
[0] == aRING
)
928 if (dent
->attr
& ATTR_VOLUME
) {
929 if ((dent
->attr
& ATTR_VFAT
) == ATTR_VFAT
&&
930 (dent
->name
[0] & LAST_LONG_ENTRY_MASK
)) {
932 dent
= extract_vfat_name(itr
);
934 * If succeeded, dent has a valid short file
935 * name entry for the current entry.
936 * If failed, itr points to a current bogus
937 * entry. So after fetching a next one,
938 * it may have a short file name entry
939 * for this bogus entry so that we can still
940 * check for a short name.
944 itr
->name
= itr
->l_name
;
947 /* Volume label or VFAT entry, skip */
950 } else if (!(dent
->attr
& ATTR_ARCH
) &&
951 !(dent
->attr
& ATTR_DIR
))
954 /* short file name */
958 get_name(dent
, itr
->s_name
);
960 itr
->name
= itr
->s_name
;
966 * fat_itr_isdir() - is current cursor position pointing to a directory
969 * @return true if cursor is at a directory
971 static int fat_itr_isdir(fat_itr
*itr
)
973 return !!(itr
->dent
->attr
& ATTR_DIR
);
980 #define TYPE_FILE 0x1
982 #define TYPE_ANY (TYPE_FILE | TYPE_DIR)
985 * fat_itr_resolve() - traverse directory structure to resolve the
988 * Traverse directory structure to the requested path. If the specified
989 * path is to a directory, this will descend into the directory and
990 * leave it iterator at the start of the directory. If the path is to a
991 * file, it will leave the iterator in the parent directory with current
992 * cursor at file's entry in the directory.
994 * @itr: iterator initialized to root
995 * @path: the requested path
996 * @type: bitmask of allowable file types
997 * @return 0 on success or -errno
999 static int fat_itr_resolve(fat_itr
*itr
, const char *path
, unsigned type
)
1003 /* chomp any extra leading slashes: */
1004 while (path
[0] && ISDIRDELIM(path
[0]))
1007 /* are we at the end? */
1008 if (strlen(path
) == 0) {
1009 if (!(type
& TYPE_DIR
))
1014 /* find length of next path entry: */
1016 while (next
[0] && !ISDIRDELIM(next
[0]))
1020 /* root dir doesn't have "." nor ".." */
1021 if ((((next
- path
) == 1) && !strncmp(path
, ".", 1)) ||
1022 (((next
- path
) == 2) && !strncmp(path
, "..", 2))) {
1023 /* point back to itself */
1024 itr
->clust
= itr
->fsdata
->root_cluster
;
1025 itr
->next_clust
= itr
->fsdata
->root_cluster
;
1028 itr
->last_cluster
= 0;
1031 if (type
& TYPE_DIR
)
1037 return fat_itr_resolve(itr
, next
, type
);
1041 while (fat_itr_next(itr
)) {
1043 unsigned n
= max(strlen(itr
->name
), (size_t)(next
- path
));
1045 /* check both long and short name: */
1046 if (!strncasecmp(path
, itr
->name
, n
))
1048 else if (itr
->name
!= itr
->s_name
&&
1049 !strncasecmp(path
, itr
->s_name
, n
))
1055 if (fat_itr_isdir(itr
)) {
1056 /* recurse into directory: */
1057 fat_itr_child(itr
, itr
);
1058 return fat_itr_resolve(itr
, next
, type
);
1059 } else if (next
[0]) {
1061 * If next is not empty then we have a case
1062 * like: /path/to/realfile/nonsense
1064 debug("bad trailing path: %s\n", next
);
1066 } else if (!(type
& TYPE_FILE
)) {
1076 int file_fat_detectfs(void)
1079 volume_info volinfo
;
1083 if (cur_dev
== NULL
) {
1084 printf("No current device\n");
1088 #if defined(CONFIG_IDE) || \
1089 defined(CONFIG_SATA) || \
1090 defined(CONFIG_SCSI) || \
1091 defined(CONFIG_CMD_USB) || \
1093 printf("Interface: ");
1094 switch (cur_dev
->if_type
) {
1120 printf("\n Device %d: ", cur_dev
->devnum
);
1124 if (read_bootsectandvi(&bs
, &volinfo
, &fatsize
)) {
1125 printf("\nNo valid FAT fs found\n");
1129 memcpy(vol_label
, volinfo
.volume_label
, 11);
1130 vol_label
[11] = '\0';
1131 volinfo
.fs_type
[5] = '\0';
1133 printf("Filesystem: %s \"%s\"\n", volinfo
.fs_type
, vol_label
);
1138 int fat_exists(const char *filename
)
1144 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1147 ret
= fat_itr_root(itr
, &fsdata
);
1151 ret
= fat_itr_resolve(itr
, filename
, TYPE_ANY
);
1152 free(fsdata
.fatbuf
);
1158 int fat_size(const char *filename
, loff_t
*size
)
1164 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1167 ret
= fat_itr_root(itr
, &fsdata
);
1171 ret
= fat_itr_resolve(itr
, filename
, TYPE_FILE
);
1174 * Directories don't have size, but fs_size() is not
1175 * expected to fail if passed a directory path:
1177 free(fsdata
.fatbuf
);
1178 ret
= fat_itr_root(itr
, &fsdata
);
1181 ret
= fat_itr_resolve(itr
, filename
, TYPE_DIR
);
1187 *size
= FAT2CPU32(itr
->dent
->size
);
1189 free(fsdata
.fatbuf
);
1195 int file_fat_read_at(const char *filename
, loff_t pos
, void *buffer
,
1196 loff_t maxsize
, loff_t
*actread
)
1202 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1205 ret
= fat_itr_root(itr
, &fsdata
);
1209 ret
= fat_itr_resolve(itr
, filename
, TYPE_FILE
);
1213 debug("reading %s at pos %llu\n", filename
, pos
);
1215 /* For saving default max clustersize memory allocated to malloc pool */
1216 dir_entry
*dentptr
= itr
->dent
;
1218 ret
= get_contents(&fsdata
, dentptr
, pos
, buffer
, maxsize
, actread
);
1221 free(fsdata
.fatbuf
);
1227 int file_fat_read(const char *filename
, void *buffer
, int maxsize
)
1232 ret
= file_fat_read_at(filename
, 0, buffer
, maxsize
, &actread
);
1239 int fat_read_file(const char *filename
, void *buf
, loff_t offset
, loff_t len
,
1244 ret
= file_fat_read_at(filename
, offset
, buf
, len
, actread
);
1246 printf("** Unable to read file %s **\n", filename
);
1252 struct fs_dir_stream parent
;
1253 struct fs_dirent dirent
;
1258 int fat_opendir(const char *filename
, struct fs_dir_stream
**dirsp
)
1263 dir
= malloc_cache_aligned(sizeof(*dir
));
1266 memset(dir
, 0, sizeof(*dir
));
1268 ret
= fat_itr_root(&dir
->itr
, &dir
->fsdata
);
1272 ret
= fat_itr_resolve(&dir
->itr
, filename
, TYPE_DIR
);
1274 goto fail_free_both
;
1276 *dirsp
= (struct fs_dir_stream
*)dir
;
1280 free(dir
->fsdata
.fatbuf
);
1286 int fat_readdir(struct fs_dir_stream
*dirs
, struct fs_dirent
**dentp
)
1288 fat_dir
*dir
= (fat_dir
*)dirs
;
1289 struct fs_dirent
*dent
= &dir
->dirent
;
1291 if (!fat_itr_next(&dir
->itr
))
1294 memset(dent
, 0, sizeof(*dent
));
1295 strcpy(dent
->name
, dir
->itr
.name
);
1297 if (fat_itr_isdir(&dir
->itr
)) {
1298 dent
->type
= FS_DT_DIR
;
1300 dent
->type
= FS_DT_REG
;
1301 dent
->size
= FAT2CPU32(dir
->itr
.dent
->size
);
1309 void fat_closedir(struct fs_dir_stream
*dirs
)
1311 fat_dir
*dir
= (fat_dir
*)dirs
;
1312 free(dir
->fsdata
.fatbuf
);
1316 void fat_close(void)