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 <asm/cache.h>
22 #include <linux/compiler.h>
23 #include <linux/ctype.h>
26 * Convert a string to lowercase. Converts at most 'len' characters,
27 * 'len' may be larger than the length of 'str' if 'str' is NULL
30 static void downcase(char *str
, size_t len
)
32 while (*str
!= '\0' && len
--) {
38 static struct blk_desc
*cur_dev
;
39 static disk_partition_t cur_part_info
;
41 #define DOS_BOOT_MAGIC_OFFSET 0x1fe
42 #define DOS_FS_TYPE_OFFSET 0x36
43 #define DOS_FS32_TYPE_OFFSET 0x52
45 static int disk_read(__u32 block
, __u32 nr_blocks
, void *buf
)
52 ret
= blk_dread(cur_dev
, cur_part_info
.start
+ block
, nr_blocks
, buf
);
60 int fat_set_blk_dev(struct blk_desc
*dev_desc
, disk_partition_t
*info
)
62 ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer
, dev_desc
->blksz
);
65 cur_part_info
= *info
;
67 /* Make sure it has a valid FAT header */
68 if (disk_read(0, 1, buffer
) != 1) {
73 /* Check if it's actually a DOS volume */
74 if (memcmp(buffer
+ DOS_BOOT_MAGIC_OFFSET
, "\x55\xAA", 2)) {
79 /* Check for FAT12/FAT16/FAT32 filesystem */
80 if (!memcmp(buffer
+ DOS_FS_TYPE_OFFSET
, "FAT", 3))
82 if (!memcmp(buffer
+ DOS_FS32_TYPE_OFFSET
, "FAT32", 5))
89 int fat_register_device(struct blk_desc
*dev_desc
, int part_no
)
91 disk_partition_t info
;
93 /* First close any currently found FAT filesystem */
96 /* Read the partition table, if present */
97 if (part_get_info(dev_desc
, part_no
, &info
)) {
99 printf("** Partition %d not valid on device %d **\n",
100 part_no
, dev_desc
->devnum
);
105 info
.size
= dev_desc
->lba
;
106 info
.blksz
= dev_desc
->blksz
;
110 #if CONFIG_IS_ENABLED(PARTITION_UUIDS)
115 return fat_set_blk_dev(dev_desc
, &info
);
119 * Extract zero terminated short name from a directory entry.
121 static void get_name(dir_entry
*dirent
, char *s_name
)
125 memcpy(s_name
, dirent
->name
, 8);
128 while (*ptr
&& *ptr
!= ' ')
130 if (dirent
->lcase
& CASE_LOWER_BASE
)
131 downcase(s_name
, (unsigned)(ptr
- s_name
));
132 if (dirent
->ext
[0] && dirent
->ext
[0] != ' ') {
134 memcpy(ptr
, dirent
->ext
, 3);
135 if (dirent
->lcase
& CASE_LOWER_EXT
)
138 while (*ptr
&& *ptr
!= ' ')
142 if (*s_name
== DELETED_FLAG
)
144 else if (*s_name
== aRING
)
145 *s_name
= DELETED_FLAG
;
148 static int flush_dirty_fat_buffer(fsdata
*mydata
);
150 #if !CONFIG_IS_ENABLED(FAT_WRITE)
151 /* Stub for read only operation */
152 int flush_dirty_fat_buffer(fsdata
*mydata
)
160 * Get the entry at index 'entry' in a FAT (12/16/32) table.
161 * On failure 0x00 is returned.
163 static __u32
get_fatent(fsdata
*mydata
, __u32 entry
)
169 if (CHECK_CLUST(entry
, mydata
->fatsize
)) {
170 printf("Error: Invalid FAT entry: 0x%08x\n", entry
);
174 switch (mydata
->fatsize
) {
176 bufnum
= entry
/ FAT32BUFSIZE
;
177 offset
= entry
- bufnum
* FAT32BUFSIZE
;
180 bufnum
= entry
/ FAT16BUFSIZE
;
181 offset
= entry
- bufnum
* FAT16BUFSIZE
;
184 bufnum
= entry
/ FAT12BUFSIZE
;
185 offset
= entry
- bufnum
* FAT12BUFSIZE
;
189 /* Unsupported FAT size */
193 debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
194 mydata
->fatsize
, entry
, entry
, offset
, offset
);
196 /* Read a new block of FAT entries into the cache. */
197 if (bufnum
!= mydata
->fatbufnum
) {
198 __u32 getsize
= FATBUFBLOCKS
;
199 __u8
*bufptr
= mydata
->fatbuf
;
200 __u32 fatlength
= mydata
->fatlength
;
201 __u32 startblock
= bufnum
* FATBUFBLOCKS
;
203 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
204 if (startblock
+ getsize
> fatlength
)
205 getsize
= fatlength
- startblock
;
207 startblock
+= mydata
->fat_sect
; /* Offset from start of disk */
209 /* Write back the fatbuf to the disk */
210 if (flush_dirty_fat_buffer(mydata
) < 0)
213 if (disk_read(startblock
, getsize
, bufptr
) < 0) {
214 debug("Error reading FAT blocks\n");
217 mydata
->fatbufnum
= bufnum
;
220 /* Get the actual entry from the table */
221 switch (mydata
->fatsize
) {
223 ret
= FAT2CPU32(((__u32
*) mydata
->fatbuf
)[offset
]);
226 ret
= FAT2CPU16(((__u16
*) mydata
->fatbuf
)[offset
]);
229 off8
= (offset
* 3) / 2;
230 /* fatbut + off8 may be unaligned, read in byte granularity */
231 ret
= mydata
->fatbuf
[off8
] + (mydata
->fatbuf
[off8
+ 1] << 8);
237 debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
238 mydata
->fatsize
, ret
, entry
, offset
);
244 * Read at most 'size' bytes from the specified cluster into 'buffer'.
245 * Return 0 on success, -1 otherwise.
248 get_cluster(fsdata
*mydata
, __u32 clustnum
, __u8
*buffer
, unsigned long size
)
255 startsect
= clust_to_sect(mydata
, clustnum
);
257 startsect
= mydata
->rootdir_sect
;
260 debug("gc - clustnum: %d, startsect: %d\n", clustnum
, startsect
);
262 if ((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1)) {
263 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
265 debug("FAT: Misaligned buffer address (%p)\n", buffer
);
267 while (size
>= mydata
->sect_size
) {
268 ret
= disk_read(startsect
++, 1, tmpbuf
);
270 debug("Error reading data (got %d)\n", ret
);
274 memcpy(buffer
, tmpbuf
, mydata
->sect_size
);
275 buffer
+= mydata
->sect_size
;
276 size
-= mydata
->sect_size
;
279 idx
= size
/ mydata
->sect_size
;
280 ret
= disk_read(startsect
, idx
, buffer
);
282 debug("Error reading data (got %d)\n", ret
);
286 idx
*= mydata
->sect_size
;
291 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
293 ret
= disk_read(startsect
, 1, tmpbuf
);
295 debug("Error reading data (got %d)\n", ret
);
299 memcpy(buffer
, tmpbuf
, size
);
306 * get_contents() - read from file
308 * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
309 * into 'buffer'. Update the number of bytes read in *gotsize or return -1 on
312 * @mydata: file system description
313 * @dentprt: directory entry pointer
314 * @pos: position from where to read
315 * @buffer: buffer into which to read
316 * @maxsize: maximum number of bytes to read
317 * @gotsize: number of bytes actually read
318 * Return: -1 on error, otherwise 0
320 static int get_contents(fsdata
*mydata
, dir_entry
*dentptr
, loff_t pos
,
321 __u8
*buffer
, loff_t maxsize
, loff_t
*gotsize
)
323 loff_t filesize
= FAT2CPU32(dentptr
->size
);
324 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
325 __u32 curclust
= START(dentptr
);
326 __u32 endclust
, newclust
;
330 debug("Filesize: %llu bytes\n", filesize
);
332 if (pos
>= filesize
) {
333 debug("Read position past EOF: %llu\n", pos
);
337 if (maxsize
> 0 && filesize
> pos
+ maxsize
)
338 filesize
= pos
+ maxsize
;
340 debug("%llu bytes\n", filesize
);
342 actsize
= bytesperclust
;
344 /* go to cluster at pos */
345 while (actsize
<= pos
) {
346 curclust
= get_fatent(mydata
, curclust
);
347 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
348 debug("curclust: 0x%x\n", curclust
);
349 printf("Invalid FAT entry\n");
352 actsize
+= bytesperclust
;
356 actsize
-= bytesperclust
;
360 /* align to beginning of next cluster if any */
364 actsize
= min(filesize
, (loff_t
)bytesperclust
);
365 tmp_buffer
= malloc_cache_aligned(actsize
);
367 debug("Error: allocating buffer\n");
371 if (get_cluster(mydata
, curclust
, tmp_buffer
, actsize
) != 0) {
372 printf("Error reading cluster\n");
378 memcpy(buffer
, tmp_buffer
+ pos
, actsize
);
385 curclust
= get_fatent(mydata
, curclust
);
386 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
387 debug("curclust: 0x%x\n", curclust
);
388 printf("Invalid FAT entry\n");
393 actsize
= bytesperclust
;
397 /* search for consecutive clusters */
398 while (actsize
< filesize
) {
399 newclust
= get_fatent(mydata
, endclust
);
400 if ((newclust
- 1) != endclust
)
402 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
403 debug("curclust: 0x%x\n", newclust
);
404 printf("Invalid FAT entry\n");
408 actsize
+= bytesperclust
;
411 /* get remaining bytes */
413 if (get_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
414 printf("Error reading cluster\n");
420 if (get_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
421 printf("Error reading cluster\n");
424 *gotsize
+= (int)actsize
;
428 curclust
= get_fatent(mydata
, endclust
);
429 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
430 debug("curclust: 0x%x\n", curclust
);
431 printf("Invalid FAT entry\n");
434 actsize
= bytesperclust
;
440 * Extract the file name information from 'slotptr' into 'l_name',
441 * starting at l_name[*idx].
442 * Return 1 if terminator (zero byte) is found, 0 otherwise.
444 static int slot2str(dir_slot
*slotptr
, char *l_name
, int *idx
)
448 for (j
= 0; j
<= 8; j
+= 2) {
449 l_name
[*idx
] = slotptr
->name0_4
[j
];
450 if (l_name
[*idx
] == 0x00)
454 for (j
= 0; j
<= 10; j
+= 2) {
455 l_name
[*idx
] = slotptr
->name5_10
[j
];
456 if (l_name
[*idx
] == 0x00)
460 for (j
= 0; j
<= 2; j
+= 2) {
461 l_name
[*idx
] = slotptr
->name11_12
[j
];
462 if (l_name
[*idx
] == 0x00)
470 /* Calculate short name checksum */
471 static __u8
mkcksum(const char name
[8], const char ext
[3])
477 for (i
= 0; i
< 8; i
++)
478 ret
= (((ret
& 1) << 7) | ((ret
& 0xfe) >> 1)) + name
[i
];
479 for (i
= 0; i
< 3; i
++)
480 ret
= (((ret
& 1) << 7) | ((ret
& 0xfe) >> 1)) + ext
[i
];
486 * Read boot sector and volume info from a FAT filesystem
489 read_bootsectandvi(boot_sector
*bs
, volume_info
*volinfo
, int *fatsize
)
492 volume_info
*vistart
;
495 if (cur_dev
== NULL
) {
496 debug("Error: no device selected\n");
500 block
= malloc_cache_aligned(cur_dev
->blksz
);
502 debug("Error: allocating block\n");
506 if (disk_read(0, 1, block
) < 0) {
507 debug("Error: reading block\n");
511 memcpy(bs
, block
, sizeof(boot_sector
));
512 bs
->reserved
= FAT2CPU16(bs
->reserved
);
513 bs
->fat_length
= FAT2CPU16(bs
->fat_length
);
514 bs
->secs_track
= FAT2CPU16(bs
->secs_track
);
515 bs
->heads
= FAT2CPU16(bs
->heads
);
516 bs
->total_sect
= FAT2CPU32(bs
->total_sect
);
519 if (bs
->fat_length
== 0) {
521 bs
->fat32_length
= FAT2CPU32(bs
->fat32_length
);
522 bs
->flags
= FAT2CPU16(bs
->flags
);
523 bs
->root_cluster
= FAT2CPU32(bs
->root_cluster
);
524 bs
->info_sector
= FAT2CPU16(bs
->info_sector
);
525 bs
->backup_boot
= FAT2CPU16(bs
->backup_boot
);
526 vistart
= (volume_info
*)(block
+ sizeof(boot_sector
));
529 vistart
= (volume_info
*)&(bs
->fat32_length
);
532 memcpy(volinfo
, vistart
, sizeof(volume_info
));
534 if (*fatsize
== 32) {
535 if (strncmp(FAT32_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0)
538 if (strncmp(FAT12_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0) {
542 if (strncmp(FAT16_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0) {
548 debug("Error: broken fs_type sign\n");
556 static int get_fs_info(fsdata
*mydata
)
562 ret
= read_bootsectandvi(&bs
, &volinfo
, &mydata
->fatsize
);
564 debug("Error: reading boot sector\n");
568 if (mydata
->fatsize
== 32) {
569 mydata
->fatlength
= bs
.fat32_length
;
570 mydata
->total_sect
= bs
.total_sect
;
572 mydata
->fatlength
= bs
.fat_length
;
573 mydata
->total_sect
= (bs
.sectors
[1] << 8) + bs
.sectors
[0];
574 if (!mydata
->total_sect
)
575 mydata
->total_sect
= bs
.total_sect
;
577 if (!mydata
->total_sect
) /* unlikely */
578 mydata
->total_sect
= (u32
)cur_part_info
.size
;
580 mydata
->fats
= bs
.fats
;
581 mydata
->fat_sect
= bs
.reserved
;
583 mydata
->rootdir_sect
= mydata
->fat_sect
+ mydata
->fatlength
* bs
.fats
;
585 mydata
->sect_size
= (bs
.sector_size
[1] << 8) + bs
.sector_size
[0];
586 mydata
->clust_size
= bs
.cluster_size
;
587 if (mydata
->sect_size
!= cur_part_info
.blksz
) {
588 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
589 mydata
->sect_size
, cur_part_info
.blksz
);
592 if (mydata
->clust_size
== 0) {
593 printf("Error: FAT cluster size not set\n");
596 if ((unsigned int)mydata
->clust_size
* mydata
->sect_size
>
598 printf("Error: FAT cluster size too big (cs=%u, max=%u)\n",
599 (unsigned int)mydata
->clust_size
* mydata
->sect_size
,
604 if (mydata
->fatsize
== 32) {
605 mydata
->data_begin
= mydata
->rootdir_sect
-
606 (mydata
->clust_size
* 2);
607 mydata
->root_cluster
= bs
.root_cluster
;
609 mydata
->rootdir_size
= ((bs
.dir_entries
[1] * (int)256 +
613 mydata
->data_begin
= mydata
->rootdir_sect
+
614 mydata
->rootdir_size
-
615 (mydata
->clust_size
* 2);
618 * The root directory is not cluster-aligned and may be on a
619 * "negative" cluster, this will be handled specially in
622 mydata
->root_cluster
= 0;
625 mydata
->fatbufnum
= -1;
626 mydata
->fat_dirty
= 0;
627 mydata
->fatbuf
= malloc_cache_aligned(FATBUFSIZE
);
628 if (mydata
->fatbuf
== NULL
) {
629 debug("Error: allocating memory\n");
633 debug("FAT%d, fat_sect: %d, fatlength: %d\n",
634 mydata
->fatsize
, mydata
->fat_sect
, mydata
->fatlength
);
635 debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
636 "Data begins at: %d\n",
637 mydata
->root_cluster
,
638 mydata
->rootdir_sect
,
639 mydata
->rootdir_sect
* mydata
->sect_size
, mydata
->data_begin
);
640 debug("Sector size: %d, cluster size: %d\n", mydata
->sect_size
,
648 * Directory iterator, to simplify filesystem traversal
650 * Implements an iterator pattern to traverse directory tables,
651 * transparently handling directory tables split across multiple
652 * clusters, and the difference between FAT12/FAT16 root directory
653 * (contiguous) and subdirectories + FAT32 root (chained).
657 * for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) {
658 * // to traverse down to a subdirectory pointed to by
659 * // current iterator position:
660 * fat_itr_child(&itr, &itr);
663 * For more complete example, see fat_itr_resolve()
667 fsdata
*fsdata
; /* filesystem parameters */
668 unsigned start_clust
; /* first cluster */
669 unsigned clust
; /* current cluster */
670 unsigned next_clust
; /* next cluster if remaining == 0 */
671 int last_cluster
; /* set once we've read last cluster */
672 int is_root
; /* is iterator at root directory */
673 int remaining
; /* remaining dent's in current cluster */
675 /* current iterator position values: */
676 dir_entry
*dent
; /* current directory entry */
677 char l_name
[VFAT_MAXLEN_BYTES
]; /* long (vfat) name */
678 char s_name
[14]; /* short 8.3 name */
679 char *name
; /* l_name if there is one, else s_name */
681 /* storage for current cluster in memory: */
682 u8 block
[MAX_CLUSTSIZE
] __aligned(ARCH_DMA_MINALIGN
);
685 static int fat_itr_isdir(fat_itr
*itr
);
688 * fat_itr_root() - initialize an iterator to start at the root
691 * @itr: iterator to initialize
692 * @fsdata: filesystem data for the partition
693 * @return 0 on success, else -errno
695 static int fat_itr_root(fat_itr
*itr
, fsdata
*fsdata
)
697 if (get_fs_info(fsdata
))
700 itr
->fsdata
= fsdata
;
701 itr
->start_clust
= 0;
702 itr
->clust
= fsdata
->root_cluster
;
703 itr
->next_clust
= fsdata
->root_cluster
;
706 itr
->last_cluster
= 0;
713 * fat_itr_child() - initialize an iterator to descend into a sub-
716 * Initializes 'itr' to iterate the contents of the directory at
717 * the current cursor position of 'parent'. It is an error to
718 * call this if the current cursor of 'parent' is pointing at a
721 * Note that 'itr' and 'parent' can be the same pointer if you do
722 * not need to preserve 'parent' after this call, which is useful
723 * for traversing directory structure to resolve a file/directory.
725 * @itr: iterator to initialize
726 * @parent: the iterator pointing at a directory entry in the
727 * parent directory of the directory to iterate
729 static void fat_itr_child(fat_itr
*itr
, fat_itr
*parent
)
731 fsdata
*mydata
= parent
->fsdata
; /* for silly macros */
732 unsigned clustnum
= START(parent
->dent
);
734 assert(fat_itr_isdir(parent
));
736 itr
->fsdata
= parent
->fsdata
;
737 itr
->start_clust
= clustnum
;
739 itr
->clust
= clustnum
;
740 itr
->next_clust
= clustnum
;
743 itr
->clust
= parent
->fsdata
->root_cluster
;
744 itr
->next_clust
= parent
->fsdata
->root_cluster
;
749 itr
->last_cluster
= 0;
752 static void *next_cluster(fat_itr
*itr
, unsigned *nbytes
)
754 fsdata
*mydata
= itr
->fsdata
; /* for silly macros */
759 /* have we reached the end? */
760 if (itr
->last_cluster
)
763 if (itr
->is_root
&& itr
->fsdata
->fatsize
!= 32) {
765 * The root directory is located before the data area and
766 * cannot be indexed using the regular unsigned cluster
767 * numbers (it may start at a "negative" cluster or not at a
768 * cluster boundary at all), so consider itr->next_clust to be
769 * a offset in cluster-sized units from the start of rootdir.
771 unsigned sect_offset
= itr
->next_clust
* itr
->fsdata
->clust_size
;
772 unsigned remaining_sects
= itr
->fsdata
->rootdir_size
- sect_offset
;
773 sect
= itr
->fsdata
->rootdir_sect
+ sect_offset
;
774 /* do not read past the end of rootdir */
775 read_size
= min_t(u32
, itr
->fsdata
->clust_size
,
778 sect
= clust_to_sect(itr
->fsdata
, itr
->next_clust
);
779 read_size
= itr
->fsdata
->clust_size
;
782 debug("FAT read(sect=%d), clust_size=%d, read_size=%u, DIRENTSPERBLOCK=%zd\n",
783 sect
, itr
->fsdata
->clust_size
, read_size
, DIRENTSPERBLOCK
);
786 * NOTE: do_fat_read_at() had complicated logic to deal w/
787 * vfat names that span multiple clusters in the fat16 case,
788 * which get_dentfromdir() probably also needed (and was
789 * missing). And not entirely sure what fat32 didn't have
790 * the same issue.. We solve that by only caring about one
791 * dent at a time and iteratively constructing the vfat long
794 ret
= disk_read(sect
, read_size
, itr
->block
);
796 debug("Error: reading block\n");
800 *nbytes
= read_size
* itr
->fsdata
->sect_size
;
801 itr
->clust
= itr
->next_clust
;
802 if (itr
->is_root
&& itr
->fsdata
->fatsize
!= 32) {
804 if (itr
->next_clust
* itr
->fsdata
->clust_size
>=
805 itr
->fsdata
->rootdir_size
) {
806 debug("nextclust: 0x%x\n", itr
->next_clust
);
807 itr
->last_cluster
= 1;
810 itr
->next_clust
= get_fatent(itr
->fsdata
, itr
->next_clust
);
811 if (CHECK_CLUST(itr
->next_clust
, itr
->fsdata
->fatsize
)) {
812 debug("nextclust: 0x%x\n", itr
->next_clust
);
813 itr
->last_cluster
= 1;
820 static dir_entry
*next_dent(fat_itr
*itr
)
822 if (itr
->remaining
== 0) {
824 struct dir_entry
*dent
= next_cluster(itr
, &nbytes
);
826 /* have we reached the last cluster? */
828 /* a sign for no more entries left */
833 itr
->remaining
= nbytes
/ sizeof(dir_entry
) - 1;
840 /* have we reached the last valid entry? */
841 if (itr
->dent
->name
[0] == 0)
847 static dir_entry
*extract_vfat_name(fat_itr
*itr
)
849 struct dir_entry
*dent
= itr
->dent
;
850 int seqn
= itr
->dent
->name
[0] & ~LAST_LONG_ENTRY_MASK
;
851 u8 chksum
, alias_checksum
= ((dir_slot
*)dent
)->alias_checksum
;
858 slot2str((dir_slot
*)dent
, buf
, &idx
);
860 if (n
+ idx
>= sizeof(itr
->l_name
))
863 /* shift accumulated long-name up and copy new part in: */
864 memmove(itr
->l_name
+ idx
, itr
->l_name
, n
);
865 memcpy(itr
->l_name
, buf
, idx
);
868 dent
= next_dent(itr
);
874 * We are now at the short file name entry.
875 * If it is marked as deleted, just skip it.
877 if (dent
->name
[0] == DELETED_FLAG
||
878 dent
->name
[0] == aRING
)
881 itr
->l_name
[n
] = '\0';
883 chksum
= mkcksum(dent
->name
, dent
->ext
);
885 /* checksum mismatch could mean deleted file, etc.. skip it: */
886 if (chksum
!= alias_checksum
) {
887 debug("** chksum=%x, alias_checksum=%x, l_name=%s, s_name=%8s.%3s\n",
888 chksum
, alias_checksum
, itr
->l_name
, dent
->name
, dent
->ext
);
896 * fat_itr_next() - step to the next entry in a directory
898 * Must be called once on a new iterator before the cursor is valid.
900 * @itr: the iterator to iterate
901 * @return boolean, 1 if success or 0 if no more entries in the
904 static int fat_itr_next(fat_itr
*itr
)
911 * One logical directory entry consist of following slots:
913 * dent[N - N]: LFN[N - 1] N|0x40 ATTR_VFAT
915 * dent[N - 2]: LFN[1] 2 ATTR_VFAT
916 * dent[N - 1]: LFN[0] 1 ATTR_VFAT
917 * dent[N]: SFN ATTR_ARCH
921 dent
= next_dent(itr
);
925 if (dent
->name
[0] == DELETED_FLAG
||
926 dent
->name
[0] == aRING
)
929 if (dent
->attr
& ATTR_VOLUME
) {
930 if ((dent
->attr
& ATTR_VFAT
) == ATTR_VFAT
&&
931 (dent
->name
[0] & LAST_LONG_ENTRY_MASK
)) {
933 dent
= extract_vfat_name(itr
);
935 * If succeeded, dent has a valid short file
936 * name entry for the current entry.
937 * If failed, itr points to a current bogus
938 * entry. So after fetching a next one,
939 * it may have a short file name entry
940 * for this bogus entry so that we can still
941 * check for a short name.
945 itr
->name
= itr
->l_name
;
948 /* Volume label or VFAT entry, skip */
951 } else if (!(dent
->attr
& ATTR_ARCH
) &&
952 !(dent
->attr
& ATTR_DIR
))
955 /* short file name */
959 get_name(dent
, itr
->s_name
);
961 itr
->name
= itr
->s_name
;
967 * fat_itr_isdir() - is current cursor position pointing to a directory
970 * @return true if cursor is at a directory
972 static int fat_itr_isdir(fat_itr
*itr
)
974 return !!(itr
->dent
->attr
& ATTR_DIR
);
981 #define TYPE_FILE 0x1
983 #define TYPE_ANY (TYPE_FILE | TYPE_DIR)
986 * fat_itr_resolve() - traverse directory structure to resolve the
989 * Traverse directory structure to the requested path. If the specified
990 * path is to a directory, this will descend into the directory and
991 * leave it iterator at the start of the directory. If the path is to a
992 * file, it will leave the iterator in the parent directory with current
993 * cursor at file's entry in the directory.
995 * @itr: iterator initialized to root
996 * @path: the requested path
997 * @type: bitmask of allowable file types
998 * @return 0 on success or -errno
1000 static int fat_itr_resolve(fat_itr
*itr
, const char *path
, unsigned type
)
1004 /* chomp any extra leading slashes: */
1005 while (path
[0] && ISDIRDELIM(path
[0]))
1008 /* are we at the end? */
1009 if (strlen(path
) == 0) {
1010 if (!(type
& TYPE_DIR
))
1015 /* find length of next path entry: */
1017 while (next
[0] && !ISDIRDELIM(next
[0]))
1021 /* root dir doesn't have "." nor ".." */
1022 if ((((next
- path
) == 1) && !strncmp(path
, ".", 1)) ||
1023 (((next
- path
) == 2) && !strncmp(path
, "..", 2))) {
1024 /* point back to itself */
1025 itr
->clust
= itr
->fsdata
->root_cluster
;
1026 itr
->next_clust
= itr
->fsdata
->root_cluster
;
1029 itr
->last_cluster
= 0;
1032 if (type
& TYPE_DIR
)
1038 return fat_itr_resolve(itr
, next
, type
);
1042 while (fat_itr_next(itr
)) {
1044 unsigned n
= max(strlen(itr
->name
), (size_t)(next
- path
));
1046 /* check both long and short name: */
1047 if (!strncasecmp(path
, itr
->name
, n
))
1049 else if (itr
->name
!= itr
->s_name
&&
1050 !strncasecmp(path
, itr
->s_name
, n
))
1056 if (fat_itr_isdir(itr
)) {
1057 /* recurse into directory: */
1058 fat_itr_child(itr
, itr
);
1059 return fat_itr_resolve(itr
, next
, type
);
1060 } else if (next
[0]) {
1062 * If next is not empty then we have a case
1063 * like: /path/to/realfile/nonsense
1065 debug("bad trailing path: %s\n", next
);
1067 } else if (!(type
& TYPE_FILE
)) {
1077 int file_fat_detectfs(void)
1080 volume_info volinfo
;
1084 if (cur_dev
== NULL
) {
1085 printf("No current device\n");
1089 #if defined(CONFIG_IDE) || \
1090 defined(CONFIG_SATA) || \
1091 defined(CONFIG_SCSI) || \
1092 defined(CONFIG_CMD_USB) || \
1094 printf("Interface: ");
1095 switch (cur_dev
->if_type
) {
1121 printf("\n Device %d: ", cur_dev
->devnum
);
1125 if (read_bootsectandvi(&bs
, &volinfo
, &fatsize
)) {
1126 printf("\nNo valid FAT fs found\n");
1130 memcpy(vol_label
, volinfo
.volume_label
, 11);
1131 vol_label
[11] = '\0';
1132 volinfo
.fs_type
[5] = '\0';
1134 printf("Filesystem: %s \"%s\"\n", volinfo
.fs_type
, vol_label
);
1139 int fat_exists(const char *filename
)
1145 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1148 ret
= fat_itr_root(itr
, &fsdata
);
1152 ret
= fat_itr_resolve(itr
, filename
, TYPE_ANY
);
1153 free(fsdata
.fatbuf
);
1159 int fat_size(const char *filename
, loff_t
*size
)
1165 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1168 ret
= fat_itr_root(itr
, &fsdata
);
1172 ret
= fat_itr_resolve(itr
, filename
, TYPE_FILE
);
1175 * Directories don't have size, but fs_size() is not
1176 * expected to fail if passed a directory path:
1178 free(fsdata
.fatbuf
);
1179 ret
= fat_itr_root(itr
, &fsdata
);
1182 ret
= fat_itr_resolve(itr
, filename
, TYPE_DIR
);
1188 *size
= FAT2CPU32(itr
->dent
->size
);
1190 free(fsdata
.fatbuf
);
1196 int file_fat_read_at(const char *filename
, loff_t pos
, void *buffer
,
1197 loff_t maxsize
, loff_t
*actread
)
1203 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1206 ret
= fat_itr_root(itr
, &fsdata
);
1210 ret
= fat_itr_resolve(itr
, filename
, TYPE_FILE
);
1214 debug("reading %s at pos %llu\n", filename
, pos
);
1216 /* For saving default max clustersize memory allocated to malloc pool */
1217 dir_entry
*dentptr
= itr
->dent
;
1219 ret
= get_contents(&fsdata
, dentptr
, pos
, buffer
, maxsize
, actread
);
1222 free(fsdata
.fatbuf
);
1228 int file_fat_read(const char *filename
, void *buffer
, int maxsize
)
1233 ret
= file_fat_read_at(filename
, 0, buffer
, maxsize
, &actread
);
1240 int fat_read_file(const char *filename
, void *buf
, loff_t offset
, loff_t len
,
1245 ret
= file_fat_read_at(filename
, offset
, buf
, len
, actread
);
1247 printf("** Unable to read file %s **\n", filename
);
1253 struct fs_dir_stream parent
;
1254 struct fs_dirent dirent
;
1259 int fat_opendir(const char *filename
, struct fs_dir_stream
**dirsp
)
1264 dir
= malloc_cache_aligned(sizeof(*dir
));
1267 memset(dir
, 0, sizeof(*dir
));
1269 ret
= fat_itr_root(&dir
->itr
, &dir
->fsdata
);
1273 ret
= fat_itr_resolve(&dir
->itr
, filename
, TYPE_DIR
);
1275 goto fail_free_both
;
1277 *dirsp
= (struct fs_dir_stream
*)dir
;
1281 free(dir
->fsdata
.fatbuf
);
1287 int fat_readdir(struct fs_dir_stream
*dirs
, struct fs_dirent
**dentp
)
1289 fat_dir
*dir
= (fat_dir
*)dirs
;
1290 struct fs_dirent
*dent
= &dir
->dirent
;
1292 if (!fat_itr_next(&dir
->itr
))
1295 memset(dent
, 0, sizeof(*dent
));
1296 strcpy(dent
->name
, dir
->itr
.name
);
1298 if (fat_itr_isdir(&dir
->itr
)) {
1299 dent
->type
= FS_DT_DIR
;
1301 dent
->type
= FS_DT_REG
;
1302 dent
->size
= FAT2CPU32(dir
->itr
.dent
->size
);
1310 void fat_closedir(struct fs_dir_stream
*dirs
)
1312 fat_dir
*dir
= (fat_dir
*)dirs
;
1313 free(dir
->fsdata
.fatbuf
);
1317 void fat_close(void)