4 * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
6 * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
7 * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
9 * See file CREDITS for list of people who contributed to this
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
31 #include <asm/byteorder.h>
33 #if (CONFIG_COMMANDS & CFG_CMD_FAT)
36 * Convert a string to lowercase.
41 while (*str != '\0') {
47 int (*dev_block_read)(int device, __u32 blknr, __u32 blkcnt, __u8 *buffer) = 0;
49 int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
51 /* FIXME we need to determine the start block of the
52 * partition where the DOS FS resides
57 return dev_block_read (0, startblock, getsize, bufptr);
64 fat_register_read (int (*block_read)(int, __u32, __u32, __u8 *))
66 dev_block_read = block_read;
72 * Get the first occurence of a directory delimiter ('/' or '\') in a string.
73 * Return index into string if found, -1 otherwise.
80 while (*str != '\0') {
81 if (ISDIRDELIM(*str)) return str - start;
89 * Match volume_info fs_type strings.
90 * Return 0 on match, -1 otherwise.
93 compare_sign(char *str1, char *str2)
95 char *end = str1+SIGNLEN;
110 * Extract zero terminated short name from a directory entry.
112 static void get_name (dir_entry *dirent, char *s_name)
116 memcpy (s_name, dirent->name, 8);
119 while (*ptr && *ptr != ' ')
121 if (dirent->ext[0] && dirent->ext[0] != ' ') {
124 memcpy (ptr, dirent->ext, 3);
126 while (*ptr && *ptr != ' ')
130 if (*s_name == DELETED_FLAG)
132 else if (*s_name == aRING)
138 * Get the entry at index 'entry' in a FAT (12/16/32) table.
139 * On failure 0x00 is returned.
142 get_fatent(fsdata *mydata, __u32 entry)
148 switch (mydata->fatsize) {
150 bufnum = entry / FAT32BUFSIZE;
151 offset = entry - bufnum * FAT32BUFSIZE;
154 bufnum = entry / FAT16BUFSIZE;
155 offset = entry - bufnum * FAT16BUFSIZE;
158 bufnum = entry / FAT12BUFSIZE;
159 offset = entry - bufnum * FAT12BUFSIZE;
163 /* Unsupported FAT size */
167 /* Read a new block of FAT entries into the cache. */
168 if (bufnum != mydata->fatbufnum) {
169 int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
170 __u8 *bufptr = mydata->fatbuf;
171 __u32 fatlength = mydata->fatlength;
172 __u32 startblock = bufnum * FATBUFBLOCKS;
174 fatlength *= SECTOR_SIZE; /* We want it in bytes now */
175 startblock += mydata->fat_sect; /* Offset from start of disk */
177 if (getsize > fatlength) getsize = fatlength;
178 if (disk_read(startblock, getsize, bufptr) < 0) {
179 FAT_DPRINT("Error reading FAT blocks\n");
182 mydata->fatbufnum = bufnum;
185 /* Get the actual entry from the table */
186 switch (mydata->fatsize) {
188 ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
191 ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
194 __u32 off16 = (offset*3)/4;
197 switch (offset & 0x3) {
199 ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
203 val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
205 val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
207 ret = (val2 << 4) | (val1 >> 12);
210 val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
212 val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
214 ret = (val2 << 8) | (val1 >> 8);
217 ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
218 ret = (ret & 0xfff0) >> 4;
226 FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
233 * Read at most 'size' bytes from the specified cluster into 'buffer'.
234 * Return 0 on success, -1 otherwise.
237 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
243 startsect = mydata->data_begin + clustnum*mydata->clust_size;
245 startsect = mydata->rootdir_sect;
248 FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
250 if (size >= FS_BLOCK_SIZE) {
251 if (disk_read(startsect + idx, 1, buffer) < 0) {
252 FAT_DPRINT("Error reading data\n");
256 __u8 tmpbuf[FS_BLOCK_SIZE];
257 if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
258 FAT_DPRINT("Error reading data\n");
261 memcpy(buffer, tmpbuf, size);
265 buffer += FS_BLOCK_SIZE;
266 size -= FS_BLOCK_SIZE;
275 * Read at most 'maxsize' bytes from the file associated with 'dentptr'
277 * Return the number of bytes read or -1 on fatal errors.
280 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
281 unsigned long maxsize)
283 unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
284 unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
285 __u32 curclust = START(dentptr);
287 FAT_DPRINT("Filesize: %ld bytes\n", filesize);
289 if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
291 FAT_DPRINT("Reading: %ld bytes\n", filesize);
294 int getsize = (filesize > bytesperclust) ? bytesperclust :
297 if (get_cluster(mydata, curclust, buffer, getsize) != 0) {
298 FAT_ERROR("Error reading cluster\n");
303 if (filesize <= 0) return gotsize;
306 curclust = get_fatent(mydata, curclust);
307 if (curclust <= 0x0001 || curclust >= 0xfff0) {
308 FAT_DPRINT("curclust: 0x%x\n", curclust);
309 FAT_ERROR("Invalid FAT entry\n");
316 #ifdef CONFIG_SUPPORT_VFAT
318 * Extract the file name information from 'slotptr' into 'l_name',
319 * starting at l_name[*idx].
320 * Return 1 if terminator (zero byte) is found, 0 otherwise.
323 slot2str(dir_slot *slotptr, char *l_name, int *idx)
327 for (j = 0; j <= 8; j += 2) {
328 l_name[*idx] = slotptr->name0_4[j];
329 if (l_name[*idx] == 0x00) return 1;
332 for (j = 0; j <= 10; j += 2) {
333 l_name[*idx] = slotptr->name5_10[j];
334 if (l_name[*idx] == 0x00) return 1;
337 for (j = 0; j <= 2; j += 2) {
338 l_name[*idx] = slotptr->name11_12[j];
339 if (l_name[*idx] == 0x00) return 1;
348 * Extract the full long filename starting at 'retdent' (which is really
349 * a slot) into 'l_name'. If successful also copy the real directory entry
351 * Return 0 on success, -1 otherwise.
354 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
355 dir_entry *retdent, char *l_name)
358 dir_slot *slotptr = (dir_slot*) retdent;
359 __u8 *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
360 __u8 counter = slotptr->id & 0xf;
363 while ((__u8*)slotptr < nextclust) {
364 if (counter == 0) break;
365 if ((slotptr->id & 0x0f) != counter) return -1;
370 if ((__u8*)slotptr >= nextclust) {
371 __u8 block[MAX_CLUSTSIZE];
375 curclust = get_fatent(mydata, curclust);
376 if (curclust <= 0x0001 || curclust >= 0xfff0) {
377 FAT_DPRINT("curclust: 0x%x\n", curclust);
378 FAT_ERROR("Invalid FAT entry\n");
381 if (get_cluster(mydata, curclust, block,
382 mydata->clust_size * SECTOR_SIZE) != 0) {
383 FAT_DPRINT("Error: reading directory block\n");
386 slotptr2 = (dir_slot*) block;
387 while (slotptr2->id > 0x01) {
390 /* Save the real directory entry */
391 realdent = (dir_entry*)slotptr2 + 1;
392 while ((__u8*)slotptr2 >= block) {
393 slot2str(slotptr2, l_name, &idx);
397 /* Save the real directory entry */
398 realdent = (dir_entry*)slotptr;
403 if (slot2str(slotptr, l_name, &idx)) break;
404 } while (!(slotptr->id & 0x40));
407 if (*l_name == DELETED_FLAG) *l_name = '\0';
408 else if (*l_name == aRING) *l_name = 'å';
411 /* Return the real directory entry */
412 memcpy(retdent, realdent, sizeof(dir_entry));
418 /* Calculate short name checksum */
420 mkcksum(const char *str)
425 for (i = 0; i < 11; i++) {
426 ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
435 * Get the directory entry associated with 'filename' from the directory
436 * starting at 'startsect'
438 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
439 char *filename, dir_entry * retdent,
442 __u16 prevcksum = 0xffff;
443 __u8 block[MAX_CLUSTSIZE];
444 __u32 curclust = START (retdent);
445 int files = 0, dirs = 0;
447 FAT_DPRINT ("get_dentfromdir: %s\n", filename);
452 if (get_cluster (mydata, curclust, block,
453 mydata->clust_size * SECTOR_SIZE) != 0) {
454 FAT_DPRINT ("Error: reading directory block\n");
457 dentptr = (dir_entry *) block;
458 for (i = 0; i < DIRENTSPERCLUST; i++) {
459 char s_name[14], l_name[256];
462 if ((dentptr->attr & ATTR_VOLUME)) {
463 #ifdef CONFIG_SUPPORT_VFAT
464 if ((dentptr->attr & ATTR_VFAT) &&
465 (dentptr->name[0] & 0x40)) {
466 prevcksum = ((dir_slot *) dentptr)
468 get_vfatname (mydata, curclust, block,
471 int isdir = (dentptr->attr & ATTR_DIR);
481 if (l_name[0] != 0) {
488 printf (" %8ld %s%c\n",
489 (long) FAT2CPU32 (dentptr->size),
492 printf (" %s%c\n", l_name, dirc);
498 FAT_DPRINT ("vfatname: |%s|\n", l_name);
502 /* Volume label or VFAT entry */
507 if (dentptr->name[0] == 0) {
509 printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
511 FAT_DPRINT ("Dentname == NULL - %d\n", i);
514 #ifdef CONFIG_SUPPORT_VFAT
515 if (dols && mkcksum (dentptr->name) == prevcksum) {
520 get_name (dentptr, s_name);
522 int isdir = (dentptr->attr & ATTR_DIR);
532 if (s_name[0] != 0) {
539 printf (" %8ld %s%c\n",
540 (long) FAT2CPU32 (dentptr->size), s_name,
543 printf (" %s%c\n", s_name, dirc);
549 if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
550 FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
554 memcpy (retdent, dentptr, sizeof (dir_entry));
556 FAT_DPRINT ("DentName: %s", s_name);
557 FAT_DPRINT (", start: 0x%x", START (dentptr));
558 FAT_DPRINT (", size: 0x%x %s\n",
559 FAT2CPU32 (dentptr->size),
560 (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
564 curclust = get_fatent (mydata, curclust);
565 if (curclust <= 0x0001 || curclust >= 0xfff0) {
566 FAT_DPRINT ("curclust: 0x%x\n", curclust);
567 FAT_ERROR ("Invalid FAT entry\n");
577 * Read boot sector and volume info from a FAT filesystem
580 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
582 __u8 block[FS_BLOCK_SIZE];
583 volume_info *vistart;
585 if (disk_read(0, 1, block) < 0) {
586 FAT_DPRINT("Error: reading block\n");
590 memcpy(bs, block, sizeof(boot_sector));
591 bs->reserved = FAT2CPU16(bs->reserved);
592 bs->fat_length = FAT2CPU16(bs->fat_length);
593 bs->secs_track = FAT2CPU16(bs->secs_track);
594 bs->heads = FAT2CPU16(bs->heads);
596 bs->hidden = FAT2CPU32(bs->hidden);
598 bs->total_sect = FAT2CPU32(bs->total_sect);
601 if (bs->fat_length == 0) {
603 bs->fat32_length = FAT2CPU32(bs->fat32_length);
604 bs->flags = FAT2CPU16(bs->flags);
605 bs->root_cluster = FAT2CPU32(bs->root_cluster);
606 bs->info_sector = FAT2CPU16(bs->info_sector);
607 bs->backup_boot = FAT2CPU16(bs->backup_boot);
608 vistart = (volume_info*) (block + sizeof(boot_sector));
611 vistart = (volume_info*) &(bs->fat32_length);
614 memcpy(volinfo, vistart, sizeof(volume_info));
616 /* Terminate fs_type string. Writing past the end of vistart
617 is ok - it's just the buffer. */
618 vistart->fs_type[8] = '\0';
620 if (*fatsize == 32) {
621 if (compare_sign(FAT32_SIGN, vistart->fs_type) == 0) {
625 if (compare_sign(FAT12_SIGN, vistart->fs_type) == 0) {
629 if (compare_sign(FAT16_SIGN, vistart->fs_type) == 0) {
635 FAT_DPRINT("Error: broken fs_type sign\n");
641 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
644 __u8 block[FS_BLOCK_SIZE]; /* Block buffer */
645 char fnamecopy[2048];
649 fsdata *mydata = &datablock;
651 __u16 prevcksum = 0xffff;
653 int rootdir_size, cursect;
655 int files = 0, dirs = 0;
659 if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
660 FAT_DPRINT ("Error: reading boot sector\n");
663 if (mydata->fatsize == 32) {
664 mydata->fatlength = bs.fat32_length;
666 mydata->fatlength = bs.fat_length;
668 mydata->fat_sect = bs.reserved;
669 cursect = mydata->rootdir_sect
670 = mydata->fat_sect + mydata->fatlength * bs.fats;
671 mydata->clust_size = bs.cluster_size;
672 if (mydata->fatsize == 32) {
673 rootdir_size = mydata->clust_size;
674 mydata->data_begin = mydata->rootdir_sect /* + rootdir_size */
675 - (mydata->clust_size * 2);
677 rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
678 * sizeof (dir_entry)) / SECTOR_SIZE;
679 mydata->data_begin = mydata->rootdir_sect + rootdir_size
680 - (mydata->clust_size * 2);
682 mydata->fatbufnum = -1;
684 FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
686 FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
687 "Data begins at: %d\n",
688 mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
689 rootdir_size, mydata->data_begin);
690 FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
692 /* "cwd" is always the root... */
693 while (ISDIRDELIM (*filename))
695 /* Make a copy of the filename and convert it to lowercase */
696 strcpy (fnamecopy, filename);
697 downcase (fnamecopy);
698 if (*fnamecopy == '\0') {
702 } else if ((idx = dirdelim (fnamecopy)) >= 0) {
704 fnamecopy[idx] = '\0';
705 subname = fnamecopy + idx + 1;
706 /* Handle multiple delimiters */
707 while (ISDIRDELIM (*subname))
716 if (disk_read (cursect, 1, block) < 0) {
717 FAT_DPRINT ("Error: reading rootdir block\n");
720 dentptr = (dir_entry *) block;
721 for (i = 0; i < DIRENTSPERBLOCK; i++) {
722 char s_name[14], l_name[256];
725 if ((dentptr->attr & ATTR_VOLUME)) {
726 #ifdef CONFIG_SUPPORT_VFAT
727 if ((dentptr->attr & ATTR_VFAT) &&
728 (dentptr->name[0] & 0x40)) {
729 prevcksum = ((dir_slot *) dentptr)->alias_checksum;
730 get_vfatname (mydata, 0, block, dentptr, l_name);
731 if (dols == LS_ROOT) {
732 int isdir = (dentptr->attr & ATTR_DIR);
742 if (l_name[0] != 0) {
749 printf (" %8ld %s%c\n",
750 (long) FAT2CPU32 (dentptr->size),
753 printf (" %s%c\n", l_name, dirc);
759 FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
763 /* Volume label or VFAT entry */
767 } else if (dentptr->name[0] == 0) {
768 FAT_DPRINT ("RootDentname == NULL - %d\n", i);
769 if (dols == LS_ROOT) {
770 printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
775 #ifdef CONFIG_SUPPORT_VFAT
776 else if (dols == LS_ROOT
777 && mkcksum (dentptr->name) == prevcksum) {
782 get_name (dentptr, s_name);
783 if (dols == LS_ROOT) {
784 int isdir = (dentptr->attr & ATTR_DIR);
794 if (s_name[0] != 0) {
801 printf (" %8ld %s%c\n",
802 (long) FAT2CPU32 (dentptr->size), s_name,
805 printf (" %s%c\n", s_name, dirc);
811 if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
812 FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
816 if (isdir && !(dentptr->attr & ATTR_DIR))
819 FAT_DPRINT ("RootName: %s", s_name);
820 FAT_DPRINT (", start: 0x%x", START (dentptr));
821 FAT_DPRINT (", size: 0x%x %s\n",
822 FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
824 goto rootdir_done; /* We got a match */
832 int startsect = mydata->data_begin
833 + START (dentptr) * mydata->clust_size;
835 char *nextname = NULL;
840 idx = dirdelim (subname);
843 nextname = subname + idx + 1;
844 /* Handle multiple delimiters */
845 while (ISDIRDELIM (*nextname))
847 if (dols && *nextname == '\0')
850 if (dols && firsttime) {
857 if (get_dentfromdir (mydata, startsect, subname, dentptr,
858 isdir ? 0 : dols) == NULL) {
865 if (!(dentptr->attr & ATTR_DIR))
870 ret = get_contents (mydata, dentptr, buffer, maxsize);
871 FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
878 file_fat_detectfs(void)
884 return read_bootsectandvi(&bs, &volinfo, &fatsize);
889 file_fat_ls(const char *dir)
891 return do_fat_read(dir, NULL, 0, LS_YES);
896 file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
898 return do_fat_read(filename, buffer, maxsize, LS_NO);
901 #endif /* #if (CONFIG_COMMANDS & CFG_CMD_FAT) */