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
11 #define LOG_CATEGORY LOGC_FS
20 #include <asm/byteorder.h>
24 #include <asm/cache.h>
25 #include <linux/compiler.h>
26 #include <linux/ctype.h>
29 * Convert a string to lowercase. Converts at most 'len' characters,
30 * 'len' may be larger than the length of 'str' if 'str' is NULL
33 static void downcase(char *str
, size_t len
)
35 while (*str
!= '\0' && len
--) {
41 static struct blk_desc
*cur_dev
;
42 static struct disk_partition cur_part_info
;
44 #define DOS_BOOT_MAGIC_OFFSET 0x1fe
45 #define DOS_FS_TYPE_OFFSET 0x36
46 #define DOS_FS32_TYPE_OFFSET 0x52
48 static int disk_read(__u32 block
, __u32 nr_blocks
, void *buf
)
55 ret
= blk_dread(cur_dev
, cur_part_info
.start
+ block
, nr_blocks
, buf
);
63 int fat_set_blk_dev(struct blk_desc
*dev_desc
, struct disk_partition
*info
)
65 ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer
, dev_desc
->blksz
);
68 cur_part_info
= *info
;
70 /* Make sure it has a valid FAT header */
71 if (disk_read(0, 1, buffer
) != 1) {
76 /* Check if it's actually a DOS volume */
77 if (memcmp(buffer
+ DOS_BOOT_MAGIC_OFFSET
, "\x55\xAA", 2)) {
82 /* Check for FAT12/FAT16/FAT32 filesystem */
83 if (!memcmp(buffer
+ DOS_FS_TYPE_OFFSET
, "FAT", 3))
85 if (!memcmp(buffer
+ DOS_FS32_TYPE_OFFSET
, "FAT32", 5))
92 int fat_register_device(struct blk_desc
*dev_desc
, int part_no
)
94 struct disk_partition info
;
96 /* First close any currently found FAT filesystem */
99 /* Read the partition table, if present */
100 if (part_get_info(dev_desc
, part_no
, &info
)) {
102 log_err("Partition %d invalid on device %d\n", part_no
,
108 info
.size
= dev_desc
->lba
;
109 info
.blksz
= dev_desc
->blksz
;
113 disk_partition_clr_uuid(&info
);
116 return fat_set_blk_dev(dev_desc
, &info
);
120 * Extract zero terminated short name from a directory entry.
122 static void get_name(dir_entry
*dirent
, char *s_name
)
126 memcpy(s_name
, dirent
->nameext
.name
, 8);
129 while (*ptr
&& *ptr
!= ' ')
131 if (dirent
->lcase
& CASE_LOWER_BASE
)
132 downcase(s_name
, (unsigned)(ptr
- s_name
));
133 if (dirent
->nameext
.ext
[0] && dirent
->nameext
.ext
[0] != ' ') {
135 memcpy(ptr
, dirent
->nameext
.ext
, 3);
136 if (dirent
->lcase
& CASE_LOWER_EXT
)
139 while (*ptr
&& *ptr
!= ' ')
143 if (*s_name
== DELETED_FLAG
)
145 else if (*s_name
== aRING
)
146 *s_name
= DELETED_FLAG
;
149 static int flush_dirty_fat_buffer(fsdata
*mydata
);
151 #if !CONFIG_IS_ENABLED(FAT_WRITE)
152 /* Stub for read only operation */
153 int flush_dirty_fat_buffer(fsdata
*mydata
)
161 * Get the entry at index 'entry' in a FAT (12/16/32) table.
162 * On failure 0x00 is returned.
164 static __u32
get_fatent(fsdata
*mydata
, __u32 entry
)
170 if (CHECK_CLUST(entry
, mydata
->fatsize
)) {
171 log_err("Invalid FAT entry: %#08x\n", entry
);
175 switch (mydata
->fatsize
) {
177 bufnum
= entry
/ FAT32BUFSIZE
;
178 offset
= entry
- bufnum
* FAT32BUFSIZE
;
181 bufnum
= entry
/ FAT16BUFSIZE
;
182 offset
= entry
- bufnum
* FAT16BUFSIZE
;
185 bufnum
= entry
/ FAT12BUFSIZE
;
186 offset
= entry
- bufnum
* FAT12BUFSIZE
;
190 /* Unsupported FAT size */
194 debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
195 mydata
->fatsize
, entry
, entry
, offset
, offset
);
197 /* Read a new block of FAT entries into the cache. */
198 if (bufnum
!= mydata
->fatbufnum
) {
199 __u32 getsize
= FATBUFBLOCKS
;
200 __u8
*bufptr
= mydata
->fatbuf
;
201 __u32 fatlength
= mydata
->fatlength
;
202 __u32 startblock
= bufnum
* FATBUFBLOCKS
;
204 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
205 if (startblock
+ getsize
> fatlength
)
206 getsize
= fatlength
- startblock
;
208 startblock
+= mydata
->fat_sect
; /* Offset from start of disk */
210 /* Write back the fatbuf to the disk */
211 if (flush_dirty_fat_buffer(mydata
) < 0)
214 if (disk_read(startblock
, getsize
, bufptr
) < 0) {
215 debug("Error reading FAT blocks\n");
218 mydata
->fatbufnum
= bufnum
;
221 /* Get the actual entry from the table */
222 switch (mydata
->fatsize
) {
224 ret
= FAT2CPU32(((__u32
*) mydata
->fatbuf
)[offset
]);
227 ret
= FAT2CPU16(((__u16
*) mydata
->fatbuf
)[offset
]);
230 off8
= (offset
* 3) / 2;
231 /* fatbut + off8 may be unaligned, read in byte granularity */
232 ret
= mydata
->fatbuf
[off8
] + (mydata
->fatbuf
[off8
+ 1] << 8);
238 debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
239 mydata
->fatsize
, ret
, entry
, offset
);
245 * Read at most 'size' bytes from the specified cluster into 'buffer'.
246 * Return 0 on success, -1 otherwise.
249 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
;
278 } else if (size
>= mydata
->sect_size
) {
280 __u32 sect_count
= size
/ mydata
->sect_size
;
282 ret
= disk_read(startsect
, sect_count
, buffer
);
283 if (ret
!= sect_count
) {
284 debug("Error reading data (got %d)\n", ret
);
287 bytes_read
= sect_count
* mydata
->sect_size
;
288 startsect
+= sect_count
;
289 buffer
+= bytes_read
;
293 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
295 ret
= disk_read(startsect
, 1, tmpbuf
);
297 debug("Error reading data (got %d)\n", ret
);
301 memcpy(buffer
, tmpbuf
, size
);
308 * get_contents() - read from file
310 * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
311 * into 'buffer'. Update the number of bytes read in *gotsize or return -1 on
314 * @mydata: file system description
315 * @dentprt: directory entry pointer
316 * @pos: position from where to read
317 * @buffer: buffer into which to read
318 * @maxsize: maximum number of bytes to read
319 * @gotsize: number of bytes actually read
320 * Return: -1 on error, otherwise 0
322 static int get_contents(fsdata
*mydata
, dir_entry
*dentptr
, loff_t pos
,
323 __u8
*buffer
, loff_t maxsize
, loff_t
*gotsize
)
325 loff_t filesize
= FAT2CPU32(dentptr
->size
);
326 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
327 __u32 curclust
= START(dentptr
);
328 __u32 endclust
, newclust
;
332 debug("Filesize: %llu bytes\n", filesize
);
334 if (pos
>= filesize
) {
335 debug("Read position past EOF: %llu\n", pos
);
339 if (maxsize
> 0 && filesize
> pos
+ maxsize
)
340 filesize
= pos
+ maxsize
;
342 debug("%llu bytes\n", filesize
);
344 actsize
= bytesperclust
;
346 /* go to cluster at pos */
347 while (actsize
<= pos
) {
348 curclust
= get_fatent(mydata
, curclust
);
349 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
350 debug("curclust: 0x%x\n", curclust
);
351 printf("Invalid FAT entry\n");
354 actsize
+= bytesperclust
;
358 actsize
-= bytesperclust
;
362 /* align to beginning of next cluster if any */
366 actsize
= min(filesize
, (loff_t
)bytesperclust
);
367 tmp_buffer
= malloc_cache_aligned(actsize
);
369 debug("Error: allocating buffer\n");
373 if (get_cluster(mydata
, curclust
, tmp_buffer
, actsize
) != 0) {
374 printf("Error reading cluster\n");
380 memcpy(buffer
, tmp_buffer
+ pos
, actsize
);
387 curclust
= get_fatent(mydata
, curclust
);
388 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
389 debug("curclust: 0x%x\n", curclust
);
390 printf("Invalid FAT entry\n");
395 actsize
= bytesperclust
;
399 /* search for consecutive clusters */
400 while (actsize
< filesize
) {
401 newclust
= get_fatent(mydata
, endclust
);
402 if ((newclust
- 1) != endclust
)
404 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
405 debug("curclust: 0x%x\n", newclust
);
406 printf("Invalid FAT entry\n");
410 actsize
+= bytesperclust
;
413 /* get remaining bytes */
415 if (get_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
416 printf("Error reading cluster\n");
422 if (get_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
423 printf("Error reading cluster\n");
426 *gotsize
+= (int)actsize
;
430 curclust
= get_fatent(mydata
, endclust
);
431 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
432 debug("curclust: 0x%x\n", curclust
);
433 printf("Invalid FAT entry\n");
436 actsize
= bytesperclust
;
442 * Extract the file name information from 'slotptr' into 'l_name',
443 * starting at l_name[*idx].
444 * Return 1 if terminator (zero byte) is found, 0 otherwise.
446 static int slot2str(dir_slot
*slotptr
, char *l_name
, int *idx
)
450 for (j
= 0; j
<= 8; j
+= 2) {
451 l_name
[*idx
] = slotptr
->name0_4
[j
];
452 if (l_name
[*idx
] == 0x00)
456 for (j
= 0; j
<= 10; j
+= 2) {
457 l_name
[*idx
] = slotptr
->name5_10
[j
];
458 if (l_name
[*idx
] == 0x00)
462 for (j
= 0; j
<= 2; j
+= 2) {
463 l_name
[*idx
] = slotptr
->name11_12
[j
];
464 if (l_name
[*idx
] == 0x00)
472 /* Calculate short name checksum */
473 static __u8
mkcksum(struct nameext
*nameext
)
476 u8
*pos
= (void *)nameext
;
480 for (i
= 0; i
< 11; i
++)
481 ret
= (((ret
& 1) << 7) | ((ret
& 0xfe) >> 1)) + pos
[i
];
487 * Read boot sector and volume info from a FAT filesystem
490 read_bootsectandvi(boot_sector
*bs
, volume_info
*volinfo
, int *fatsize
)
493 volume_info
*vistart
;
496 if (cur_dev
== NULL
) {
497 debug("Error: no device selected\n");
501 block
= malloc_cache_aligned(cur_dev
->blksz
);
503 debug("Error: allocating block\n");
507 if (disk_read(0, 1, block
) < 0) {
508 debug("Error: reading block\n");
512 memcpy(bs
, block
, sizeof(boot_sector
));
513 bs
->reserved
= FAT2CPU16(bs
->reserved
);
514 bs
->fat_length
= FAT2CPU16(bs
->fat_length
);
515 bs
->secs_track
= FAT2CPU16(bs
->secs_track
);
516 bs
->heads
= FAT2CPU16(bs
->heads
);
517 bs
->total_sect
= FAT2CPU32(bs
->total_sect
);
520 if (bs
->fat_length
== 0) {
522 bs
->fat32_length
= FAT2CPU32(bs
->fat32_length
);
523 bs
->flags
= FAT2CPU16(bs
->flags
);
524 bs
->root_cluster
= FAT2CPU32(bs
->root_cluster
);
525 bs
->info_sector
= FAT2CPU16(bs
->info_sector
);
526 bs
->backup_boot
= FAT2CPU16(bs
->backup_boot
);
527 vistart
= (volume_info
*)(block
+ sizeof(boot_sector
));
530 vistart
= (volume_info
*)&(bs
->fat32_length
);
533 memcpy(volinfo
, vistart
, sizeof(volume_info
));
535 if (*fatsize
== 32) {
536 if (strncmp(FAT32_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0)
539 if (strncmp(FAT12_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0) {
543 if (strncmp(FAT16_SIGN
, vistart
->fs_type
, SIGNLEN
) == 0) {
549 debug("Error: broken fs_type sign\n");
557 static int get_fs_info(fsdata
*mydata
)
563 ret
= read_bootsectandvi(&bs
, &volinfo
, &mydata
->fatsize
);
565 debug("Error: reading boot sector\n");
569 if (mydata
->fatsize
== 32) {
570 mydata
->fatlength
= bs
.fat32_length
;
571 mydata
->total_sect
= bs
.total_sect
;
573 mydata
->fatlength
= bs
.fat_length
;
574 mydata
->total_sect
= (bs
.sectors
[1] << 8) + bs
.sectors
[0];
575 if (!mydata
->total_sect
)
576 mydata
->total_sect
= bs
.total_sect
;
578 if (!mydata
->total_sect
) /* unlikely */
579 mydata
->total_sect
= (u32
)cur_part_info
.size
;
581 mydata
->fats
= bs
.fats
;
582 mydata
->fat_sect
= bs
.reserved
;
584 mydata
->rootdir_sect
= mydata
->fat_sect
+ mydata
->fatlength
* bs
.fats
;
586 mydata
->sect_size
= (bs
.sector_size
[1] << 8) + bs
.sector_size
[0];
587 mydata
->clust_size
= bs
.cluster_size
;
588 if (mydata
->sect_size
!= cur_part_info
.blksz
) {
589 log_err("FAT sector size mismatch (fs=%u, dev=%lu)\n",
590 mydata
->sect_size
, cur_part_info
.blksz
);
593 if (mydata
->clust_size
== 0) {
594 log_err("FAT cluster size not set\n");
597 if ((unsigned int)mydata
->clust_size
* mydata
->sect_size
>
599 log_err("FAT cluster size too big (cs=%u, max=%u)\n",
600 (uint
)mydata
->clust_size
* mydata
->sect_size
,
605 if (mydata
->fatsize
== 32) {
606 mydata
->data_begin
= mydata
->rootdir_sect
-
607 (mydata
->clust_size
* 2);
608 mydata
->root_cluster
= bs
.root_cluster
;
610 mydata
->rootdir_size
= ((bs
.dir_entries
[1] * (int)256 +
614 mydata
->data_begin
= mydata
->rootdir_sect
+
615 mydata
->rootdir_size
-
616 (mydata
->clust_size
* 2);
619 * The root directory is not cluster-aligned and may be on a
620 * "negative" cluster, this will be handled specially in
621 * fat_next_cluster().
623 mydata
->root_cluster
= 0;
626 mydata
->fatbufnum
= -1;
627 mydata
->fat_dirty
= 0;
628 mydata
->fatbuf
= malloc_cache_aligned(FATBUFSIZE
);
629 if (mydata
->fatbuf
== NULL
) {
630 debug("Error: allocating memory\n");
634 debug("FAT%d, fat_sect: %d, fatlength: %d\n",
635 mydata
->fatsize
, mydata
->fat_sect
, mydata
->fatlength
);
636 debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
637 "Data begins at: %d\n",
638 mydata
->root_cluster
,
639 mydata
->rootdir_sect
,
640 mydata
->rootdir_sect
* mydata
->sect_size
, mydata
->data_begin
);
641 debug("Sector size: %d, cluster size: %d\n", mydata
->sect_size
,
648 * struct fat_itr - 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).
659 * for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) {
660 * // to traverse down to a subdirectory pointed to by
661 * // current iterator position:
662 * fat_itr_child(&itr, &itr);
665 * For a more complete example, see fat_itr_resolve().
669 * @fsdata: filesystem parameters
673 * @start_clust: first cluster
675 unsigned int start_clust
;
677 * @clust: current cluster
681 * @next_clust: next cluster if remaining == 0
683 unsigned int next_clust
;
685 * @last_cluster: set if last cluster of directory reached
689 * @is_root: is iterator at root directory
693 * @remaining: remaining directory entries in current cluster
697 * @dent: current directory entry
701 * @dent_rem: remaining entries after long name start
705 * @dent_clust: cluster of long name start
707 unsigned int dent_clust
;
709 * @dent_start: first directory entry for long name
711 dir_entry
*dent_start
;
713 * @l_name: long name of current directory entry
715 char l_name
[VFAT_MAXLEN_BYTES
];
717 * @s_name: short 8.3 name of current directory entry
721 * @name: l_name if there is one, else s_name
725 * @block: buffer for current cluster
727 u8 block
[MAX_CLUSTSIZE
] __aligned(ARCH_DMA_MINALIGN
);
730 static int fat_itr_isdir(fat_itr
*itr
);
733 * fat_itr_root() - initialize an iterator to start at the root
736 * @itr: iterator to initialize
737 * @fsdata: filesystem data for the partition
738 * Return: 0 on success, else -errno
740 static int fat_itr_root(fat_itr
*itr
, fsdata
*fsdata
)
742 if (get_fs_info(fsdata
))
745 itr
->fsdata
= fsdata
;
746 itr
->start_clust
= fsdata
->root_cluster
;
747 itr
->clust
= fsdata
->root_cluster
;
748 itr
->next_clust
= fsdata
->root_cluster
;
751 itr
->last_cluster
= 0;
758 * fat_itr_child() - initialize an iterator to descend into a sub-
761 * Initializes 'itr' to iterate the contents of the directory at
762 * the current cursor position of 'parent'. It is an error to
763 * call this if the current cursor of 'parent' is pointing at a
766 * Note that 'itr' and 'parent' can be the same pointer if you do
767 * not need to preserve 'parent' after this call, which is useful
768 * for traversing directory structure to resolve a file/directory.
770 * @itr: iterator to initialize
771 * @parent: the iterator pointing at a directory entry in the
772 * parent directory of the directory to iterate
774 static void fat_itr_child(fat_itr
*itr
, fat_itr
*parent
)
776 fsdata
*mydata
= parent
->fsdata
; /* for silly macros */
777 unsigned clustnum
= START(parent
->dent
);
779 assert(fat_itr_isdir(parent
));
781 itr
->fsdata
= parent
->fsdata
;
782 itr
->start_clust
= clustnum
;
784 itr
->clust
= clustnum
;
785 itr
->next_clust
= clustnum
;
788 itr
->clust
= parent
->fsdata
->root_cluster
;
789 itr
->next_clust
= parent
->fsdata
->root_cluster
;
790 itr
->start_clust
= parent
->fsdata
->root_cluster
;
795 itr
->last_cluster
= 0;
799 * fat_next_cluster() - load next FAT cluster
801 * The function is used when iterating through directories. It loads the
802 * next cluster with directory entries
804 * @itr: directory iterator
805 * @nbytes: number of bytes read, 0 on error
806 * Return: first directory entry, NULL on error
808 void *fat_next_cluster(fat_itr
*itr
, unsigned int *nbytes
)
814 /* have we reached the end? */
815 if (itr
->last_cluster
)
818 if (itr
->is_root
&& itr
->fsdata
->fatsize
!= 32) {
820 * The root directory is located before the data area and
821 * cannot be indexed using the regular unsigned cluster
822 * numbers (it may start at a "negative" cluster or not at a
823 * cluster boundary at all), so consider itr->next_clust to be
824 * a offset in cluster-sized units from the start of rootdir.
826 unsigned sect_offset
= itr
->next_clust
* itr
->fsdata
->clust_size
;
827 unsigned remaining_sects
= itr
->fsdata
->rootdir_size
- sect_offset
;
828 sect
= itr
->fsdata
->rootdir_sect
+ sect_offset
;
829 /* do not read past the end of rootdir */
830 read_size
= min_t(u32
, itr
->fsdata
->clust_size
,
833 sect
= clust_to_sect(itr
->fsdata
, itr
->next_clust
);
834 read_size
= itr
->fsdata
->clust_size
;
837 log_debug("FAT read(sect=%d), clust_size=%d, read_size=%u\n",
838 sect
, itr
->fsdata
->clust_size
, read_size
);
841 * NOTE: do_fat_read_at() had complicated logic to deal w/
842 * vfat names that span multiple clusters in the fat16 case,
843 * which get_dentfromdir() probably also needed (and was
844 * missing). And not entirely sure what fat32 didn't have
845 * the same issue.. We solve that by only caring about one
846 * dent at a time and iteratively constructing the vfat long
849 ret
= disk_read(sect
, read_size
, itr
->block
);
851 debug("Error: reading block\n");
855 *nbytes
= read_size
* itr
->fsdata
->sect_size
;
856 itr
->clust
= itr
->next_clust
;
857 if (itr
->is_root
&& itr
->fsdata
->fatsize
!= 32) {
859 if (itr
->next_clust
* itr
->fsdata
->clust_size
>=
860 itr
->fsdata
->rootdir_size
) {
861 debug("nextclust: 0x%x\n", itr
->next_clust
);
862 itr
->last_cluster
= 1;
865 itr
->next_clust
= get_fatent(itr
->fsdata
, itr
->next_clust
);
866 if (CHECK_CLUST(itr
->next_clust
, itr
->fsdata
->fatsize
)) {
867 debug("nextclust: 0x%x\n", itr
->next_clust
);
868 itr
->last_cluster
= 1;
875 static dir_entry
*next_dent(fat_itr
*itr
)
877 if (itr
->remaining
== 0) {
879 struct dir_entry
*dent
= fat_next_cluster(itr
, &nbytes
);
881 /* have we reached the last cluster? */
883 /* a sign for no more entries left */
888 itr
->remaining
= nbytes
/ sizeof(dir_entry
) - 1;
895 /* have we reached the last valid entry? */
896 if (itr
->dent
->nameext
.name
[0] == 0)
902 static dir_entry
*extract_vfat_name(fat_itr
*itr
)
904 struct dir_entry
*dent
= itr
->dent
;
905 int seqn
= itr
->dent
->nameext
.name
[0] & ~LAST_LONG_ENTRY_MASK
;
906 u8 chksum
, alias_checksum
= ((dir_slot
*)dent
)->alias_checksum
;
913 slot2str((dir_slot
*)dent
, buf
, &idx
);
915 if (n
+ idx
>= sizeof(itr
->l_name
))
918 /* shift accumulated long-name up and copy new part in: */
919 memmove(itr
->l_name
+ idx
, itr
->l_name
, n
);
920 memcpy(itr
->l_name
, buf
, idx
);
923 dent
= next_dent(itr
);
929 * We are now at the short file name entry.
930 * If it is marked as deleted, just skip it.
932 if (dent
->nameext
.name
[0] == DELETED_FLAG
||
933 dent
->nameext
.name
[0] == aRING
)
936 itr
->l_name
[n
] = '\0';
938 chksum
= mkcksum(&dent
->nameext
);
940 /* checksum mismatch could mean deleted file, etc.. skip it: */
941 if (chksum
!= alias_checksum
) {
942 debug("** chksum=%x, alias_checksum=%x, l_name=%s, s_name=%8s.%3s\n",
943 chksum
, alias_checksum
, itr
->l_name
, dent
->nameext
.name
,
952 * fat_itr_next() - step to the next entry in a directory
954 * Must be called once on a new iterator before the cursor is valid.
956 * @itr: the iterator to iterate
957 * Return: boolean, 1 if success or 0 if no more entries in the
960 static int fat_itr_next(fat_itr
*itr
)
967 * One logical directory entry consist of following slots:
969 * dent[N - N]: LFN[N - 1] N|0x40 ATTR_VFAT
971 * dent[N - 2]: LFN[1] 2 ATTR_VFAT
972 * dent[N - 1]: LFN[0] 1 ATTR_VFAT
973 * dent[N]: SFN ATTR_ARCH
977 dent
= next_dent(itr
);
979 itr
->dent_start
= NULL
;
982 itr
->dent_rem
= itr
->remaining
;
983 itr
->dent_start
= itr
->dent
;
984 itr
->dent_clust
= itr
->clust
;
985 if (dent
->nameext
.name
[0] == DELETED_FLAG
)
988 if (dent
->attr
& ATTR_VOLUME
) {
989 if ((dent
->attr
& ATTR_VFAT
) == ATTR_VFAT
&&
990 (dent
->nameext
.name
[0] & LAST_LONG_ENTRY_MASK
)) {
992 dent
= extract_vfat_name(itr
);
994 * If succeeded, dent has a valid short file
995 * name entry for the current entry.
996 * If failed, itr points to a current bogus
997 * entry. So after fetching a next one,
998 * it may have a short file name entry
999 * for this bogus entry so that we can still
1000 * check for a short name.
1004 itr
->name
= itr
->l_name
;
1007 /* Volume label or VFAT entry, skip */
1012 /* short file name */
1016 get_name(dent
, itr
->s_name
);
1018 itr
->name
= itr
->s_name
;
1024 * fat_itr_isdir() - is current cursor position pointing to a directory
1026 * @itr: the iterator
1027 * Return: true if cursor is at a directory
1029 static int fat_itr_isdir(fat_itr
*itr
)
1031 return !!(itr
->dent
->attr
& ATTR_DIR
);
1038 #define TYPE_FILE 0x1
1039 #define TYPE_DIR 0x2
1040 #define TYPE_ANY (TYPE_FILE | TYPE_DIR)
1043 * fat_itr_resolve() - traverse directory structure to resolve the
1046 * Traverse directory structure to the requested path. If the specified
1047 * path is to a directory, this will descend into the directory and
1048 * leave it iterator at the start of the directory. If the path is to a
1049 * file, it will leave the iterator in the parent directory with current
1050 * cursor at file's entry in the directory.
1052 * @itr: iterator initialized to root
1053 * @path: the requested path
1054 * @type: bitmask of allowable file types
1055 * Return: 0 on success or -errno
1057 static int fat_itr_resolve(fat_itr
*itr
, const char *path
, unsigned type
)
1061 /* chomp any extra leading slashes: */
1062 while (path
[0] && ISDIRDELIM(path
[0]))
1065 /* are we at the end? */
1066 if (strlen(path
) == 0) {
1067 if (!(type
& TYPE_DIR
))
1072 /* find length of next path entry: */
1074 while (next
[0] && !ISDIRDELIM(next
[0]))
1078 /* root dir doesn't have "." nor ".." */
1079 if ((((next
- path
) == 1) && !strncmp(path
, ".", 1)) ||
1080 (((next
- path
) == 2) && !strncmp(path
, "..", 2))) {
1081 /* point back to itself */
1082 itr
->clust
= itr
->fsdata
->root_cluster
;
1083 itr
->next_clust
= itr
->fsdata
->root_cluster
;
1084 itr
->start_clust
= itr
->fsdata
->root_cluster
;
1087 itr
->last_cluster
= 0;
1090 if (type
& TYPE_DIR
)
1096 return fat_itr_resolve(itr
, next
, type
);
1100 while (fat_itr_next(itr
)) {
1102 unsigned n
= max(strlen(itr
->name
), (size_t)(next
- path
));
1104 /* check both long and short name: */
1105 if (!strncasecmp(path
, itr
->name
, n
))
1107 else if (itr
->name
!= itr
->s_name
&&
1108 !strncasecmp(path
, itr
->s_name
, n
))
1114 if (fat_itr_isdir(itr
)) {
1115 /* recurse into directory: */
1116 fat_itr_child(itr
, itr
);
1117 return fat_itr_resolve(itr
, next
, type
);
1118 } else if (next
[0]) {
1120 * If next is not empty then we have a case
1121 * like: /path/to/realfile/nonsense
1123 debug("bad trailing path: %s\n", next
);
1125 } else if (!(type
& TYPE_FILE
)) {
1135 int file_fat_detectfs(void)
1138 volume_info volinfo
;
1142 if (cur_dev
== NULL
) {
1143 printf("No current device\n");
1147 if (blk_enabled()) {
1148 printf("Interface: %s\n", blk_get_uclass_name(cur_dev
->uclass_id
));
1149 printf(" Device %d: ", cur_dev
->devnum
);
1153 if (read_bootsectandvi(&bs
, &volinfo
, &fatsize
)) {
1154 printf("\nNo valid FAT fs found\n");
1158 memcpy(vol_label
, volinfo
.volume_label
, 11);
1159 vol_label
[11] = '\0';
1160 volinfo
.fs_type
[5] = '\0';
1162 printf("Filesystem: %s \"%s\"\n", volinfo
.fs_type
, vol_label
);
1167 int fat_exists(const char *filename
)
1173 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1176 ret
= fat_itr_root(itr
, &fsdata
);
1180 ret
= fat_itr_resolve(itr
, filename
, TYPE_ANY
);
1181 free(fsdata
.fatbuf
);
1188 * fat2rtc() - convert FAT time stamp to RTC file stamp
1192 * @tm: RTC time stamp
1194 static void __maybe_unused
fat2rtc(u16 date
, u16 time
, struct rtc_time
*tm
)
1196 tm
->tm_mday
= date
& 0x1f;
1197 tm
->tm_mon
= (date
& 0x1e0) >> 4;
1198 tm
->tm_year
= (date
>> 9) + 1980;
1200 tm
->tm_sec
= (time
& 0x1f) << 1;
1201 tm
->tm_min
= (time
& 0x7e0) >> 5;
1202 tm
->tm_hour
= time
>> 11;
1204 rtc_calc_weekday(tm
);
1209 int fat_size(const char *filename
, loff_t
*size
)
1215 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1218 ret
= fat_itr_root(itr
, &fsdata
);
1222 ret
= fat_itr_resolve(itr
, filename
, TYPE_FILE
);
1225 * Directories don't have size, but fs_size() is not
1226 * expected to fail if passed a directory path:
1228 free(fsdata
.fatbuf
);
1229 ret
= fat_itr_root(itr
, &fsdata
);
1232 ret
= fat_itr_resolve(itr
, filename
, TYPE_DIR
);
1238 *size
= FAT2CPU32(itr
->dent
->size
);
1240 free(fsdata
.fatbuf
);
1246 int fat_read_file(const char *filename
, void *buf
, loff_t offset
, loff_t len
,
1253 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1256 ret
= fat_itr_root(itr
, &fsdata
);
1260 ret
= fat_itr_resolve(itr
, filename
, TYPE_FILE
);
1264 debug("reading %s at pos %llu\n", filename
, offset
);
1266 /* For saving default max clustersize memory allocated to malloc pool */
1267 dir_entry
*dentptr
= itr
->dent
;
1269 ret
= get_contents(&fsdata
, dentptr
, offset
, buf
, len
, actread
);
1272 free(fsdata
.fatbuf
);
1278 int file_fat_read(const char *filename
, void *buffer
, int maxsize
)
1283 ret
= fat_read_file(filename
, buffer
, 0, maxsize
, &actread
);
1291 struct fs_dir_stream parent
;
1292 struct fs_dirent dirent
;
1297 int fat_opendir(const char *filename
, struct fs_dir_stream
**dirsp
)
1302 dir
= malloc_cache_aligned(sizeof(*dir
));
1305 memset(dir
, 0, sizeof(*dir
));
1307 ret
= fat_itr_root(&dir
->itr
, &dir
->fsdata
);
1311 ret
= fat_itr_resolve(&dir
->itr
, filename
, TYPE_DIR
);
1313 goto fail_free_both
;
1315 *dirsp
= (struct fs_dir_stream
*)dir
;
1319 free(dir
->fsdata
.fatbuf
);
1325 int fat_readdir(struct fs_dir_stream
*dirs
, struct fs_dirent
**dentp
)
1327 fat_dir
*dir
= (fat_dir
*)dirs
;
1328 struct fs_dirent
*dent
= &dir
->dirent
;
1330 if (!fat_itr_next(&dir
->itr
))
1333 memset(dent
, 0, sizeof(*dent
));
1334 strcpy(dent
->name
, dir
->itr
.name
);
1335 if (CONFIG_IS_ENABLED(EFI_LOADER
)) {
1336 dent
->attr
= dir
->itr
.dent
->attr
;
1337 fat2rtc(le16_to_cpu(dir
->itr
.dent
->cdate
),
1338 le16_to_cpu(dir
->itr
.dent
->ctime
), &dent
->create_time
);
1339 fat2rtc(le16_to_cpu(dir
->itr
.dent
->date
),
1340 le16_to_cpu(dir
->itr
.dent
->time
), &dent
->change_time
);
1341 fat2rtc(le16_to_cpu(dir
->itr
.dent
->adate
),
1342 0, &dent
->access_time
);
1344 if (fat_itr_isdir(&dir
->itr
)) {
1345 dent
->type
= FS_DT_DIR
;
1347 dent
->type
= FS_DT_REG
;
1348 dent
->size
= FAT2CPU32(dir
->itr
.dent
->size
);
1356 void fat_closedir(struct fs_dir_stream
*dirs
)
1358 fat_dir
*dir
= (fat_dir
*)dirs
;
1359 free(dir
->fsdata
.fatbuf
);
1363 void fat_close(void)
1367 int fat_uuid(char *uuid_str
)
1370 volume_info volinfo
;
1375 ret
= read_bootsectandvi(&bs
, &volinfo
, &fatsize
);
1379 id
= volinfo
.volume_id
;
1380 sprintf(uuid_str
, "%02X%02X-%02X%02X", id
[3], id
[2], id
[1], id
[0]);