fs/fat/fat.c

   1 /*
   2  * fat.c
   3  *
   4  * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
   5  *
   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
   8  *
   9  * See file CREDITS for list of people who contributed to this
  10  * project.
  11  *
  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.
  16  *
  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.
  21  *
  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,
  25  * MA 02111-1307 USA
  26  */
  27
  28 #include <common.h>
  29 #include <config.h>
  30 #include <exports.h>
  31 #include <fat.h>
  32 #include <asm/byteorder.h>
  33 #include <part.h>
  34 #include <malloc.h>
  35 #include <linux/compiler.h>
  36 #include <linux/ctype.h>
  37
  38 #ifdef CONFIG_SUPPORT_VFAT
  39 static const int vfat_enabled = 1;
  40 #else
  41 static const int vfat_enabled = 0;
  42 #endif
  43
  44 /*
  45  * Convert a string to lowercase.
  46  */
  47 static void downcase(char *str)
  48 {
  49         while (*str != '\0') {
  50                 *str = tolower(*str);
  51                 str++;
  52         }
  53 }
  54
  55 static block_dev_desc_t *cur_dev;
  56 static disk_partition_t cur_part_info;
  57
  58 #define DOS_BOOT_MAGIC_OFFSET   0x1fe
  59 #define DOS_FS_TYPE_OFFSET      0x36
  60 #define DOS_FS32_TYPE_OFFSET    0x52
  61
  62 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
  63 {
  64         if (!cur_dev || !cur_dev->block_read)
  65                 return -1;
  66
  67         return cur_dev->block_read(cur_dev->dev,
  68                         cur_part_info.start + block, nr_blocks, buf);
  69 }
  70
  71 int fat_set_blk_dev(block_dev_desc_t *dev_desc, disk_partition_t *info)
  72 {
  73         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
  74
  75         cur_dev = dev_desc;
  76         cur_part_info = *info;
  77
  78         /* Make sure it has a valid FAT header */
  79         if (disk_read(0, 1, buffer) != 1) {
  80                 cur_dev = NULL;
  81                 return -1;
  82         }
  83
  84         /* Check if it's actually a DOS volume */
  85         if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
  86                 cur_dev = NULL;
  87                 return -1;
  88         }
  89
  90         /* Check for FAT12/FAT16/FAT32 filesystem */
  91         if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
  92                 return 0;
  93         if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
  94                 return 0;
  95
  96         cur_dev = NULL;
  97         return -1;
  98 }
  99
 100 int fat_register_device(block_dev_desc_t *dev_desc, int part_no)
 101 {
 102         disk_partition_t info;
 103
 104         /* First close any currently found FAT filesystem */
 105         cur_dev = NULL;
 106
 107         /* Read the partition table, if present */
 108         if (get_partition_info(dev_desc, part_no, &info)) {
 109                 if (part_no != 0) {
 110                         printf("** Partition %d not valid on device %d **\n",
 111                                         part_no, dev_desc->dev);
 112                         return -1;
 113                 }
 114
 115                 info.start = 0;
 116                 info.size = dev_desc->lba;
 117                 info.blksz = dev_desc->blksz;
 118                 info.name[0] = 0;
 119                 info.type[0] = 0;
 120                 info.bootable = 0;
 121 #ifdef CONFIG_PARTITION_UUIDS
 122                 info.uuid[0] = 0;
 123 #endif
 124         }
 125
 126         return fat_set_blk_dev(dev_desc, &info);
 127 }
 128
 129 /*
 130  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 131  * Return index into string if found, -1 otherwise.
 132  */
 133 static int dirdelim(char *str)
 134 {
 135         char *start = str;
 136
 137         while (*str != '\0') {
 138                 if (ISDIRDELIM(*str))
 139                         return str - start;
 140                 str++;
 141         }
 142         return -1;
 143 }
 144
 145 /*
 146  * Extract zero terminated short name from a directory entry.
 147  */
 148 static void get_name(dir_entry *dirent, char *s_name)
 149 {
 150         char *ptr;
 151
 152         memcpy(s_name, dirent->name, 8);
 153         s_name[8] = '\0';
 154         ptr = s_name;
 155         while (*ptr && *ptr != ' ')
 156                 ptr++;
 157         if (dirent->ext[0] && dirent->ext[0] != ' ') {
 158                 *ptr = '.';
 159                 ptr++;
 160                 memcpy(ptr, dirent->ext, 3);
 161                 ptr[3] = '\0';
 162                 while (*ptr && *ptr != ' ')
 163                         ptr++;
 164         }
 165         *ptr = '\0';
 166         if (*s_name == DELETED_FLAG)
 167                 *s_name = '\0';
 168         else if (*s_name == aRING)
 169                 *s_name = DELETED_FLAG;
 170         downcase(s_name);
 171 }
 172
 173 /*
 174  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 175  * On failure 0x00 is returned.
 176  */
 177 static __u32 get_fatent(fsdata *mydata, __u32 entry)
 178 {
 179         __u32 bufnum;
 180         __u32 off16, offset;
 181         __u32 ret = 0x00;
 182         __u16 val1, val2;
 183
 184         switch (mydata->fatsize) {
 185         case 32:
 186                 bufnum = entry / FAT32BUFSIZE;
 187                 offset = entry - bufnum * FAT32BUFSIZE;
 188                 break;
 189         case 16:
 190                 bufnum = entry / FAT16BUFSIZE;
 191                 offset = entry - bufnum * FAT16BUFSIZE;
 192                 break;
 193         case 12:
 194                 bufnum = entry / FAT12BUFSIZE;
 195                 offset = entry - bufnum * FAT12BUFSIZE;
 196                 break;
 197
 198         default:
 199                 /* Unsupported FAT size */
 200                 return ret;
 201         }
 202
 203         debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
 204                mydata->fatsize, entry, entry, offset, offset);
 205
 206         /* Read a new block of FAT entries into the cache. */
 207         if (bufnum != mydata->fatbufnum) {
 208                 __u32 getsize = FATBUFBLOCKS;
 209                 __u8 *bufptr = mydata->fatbuf;
 210                 __u32 fatlength = mydata->fatlength;
 211                 __u32 startblock = bufnum * FATBUFBLOCKS;
 212
 213                 if (startblock + getsize > fatlength)
 214                         getsize = fatlength - startblock;
 215
 216                 startblock += mydata->fat_sect; /* Offset from start of disk */
 217
 218                 if (disk_read(startblock, getsize, bufptr) < 0) {
 219                         debug("Error reading FAT blocks\n");
 220                         return ret;
 221                 }
 222                 mydata->fatbufnum = bufnum;
 223         }
 224
 225         /* Get the actual entry from the table */
 226         switch (mydata->fatsize) {
 227         case 32:
 228                 ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
 229                 break;
 230         case 16:
 231                 ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
 232                 break;
 233         case 12:
 234                 off16 = (offset * 3) / 4;
 235
 236                 switch (offset & 0x3) {
 237                 case 0:
 238                         ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
 239                         ret &= 0xfff;
 240                         break;
 241                 case 1:
 242                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 243                         val1 &= 0xf000;
 244                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 245                         val2 &= 0x00ff;
 246                         ret = (val2 << 4) | (val1 >> 12);
 247                         break;
 248                 case 2:
 249                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 250                         val1 &= 0xff00;
 251                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 252                         val2 &= 0x000f;
 253                         ret = (val2 << 8) | (val1 >> 8);
 254                         break;
 255                 case 3:
 256                         ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 257                         ret = (ret & 0xfff0) >> 4;
 258                         break;
 259                 default:
 260                         break;
 261                 }
 262                 break;
 263         }
 264         debug("FAT%d: ret: %08x, offset: %04x\n",
 265                mydata->fatsize, ret, offset);
 266
 267         return ret;
 268 }
 269
 270 /*
 271  * Read at most 'size' bytes from the specified cluster into 'buffer'.
 272  * Return 0 on success, -1 otherwise.
 273  */
 274 static int
 275 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
 276 {
 277         __u32 idx = 0;
 278         __u32 startsect;
 279         int ret;
 280
 281         if (clustnum > 0) {
 282                 startsect = mydata->data_begin +
 283                                 clustnum * mydata->clust_size;
 284         } else {
 285                 startsect = mydata->rootdir_sect;
 286         }
 287
 288         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 289
 290         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 291                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 292
 293                 printf("FAT: Misaligned buffer address (%p)\n", buffer);
 294
 295                 while (size >= mydata->sect_size) {
 296                         ret = disk_read(startsect++, 1, tmpbuf);
 297                         if (ret != 1) {
 298                                 debug("Error reading data (got %d)\n", ret);
 299                                 return -1;
 300                         }
 301
 302                         memcpy(buffer, tmpbuf, mydata->sect_size);
 303                         buffer += mydata->sect_size;
 304                         size -= mydata->sect_size;
 305                 }
 306         } else {
 307                 idx = size / mydata->sect_size;
 308                 ret = disk_read(startsect, idx, buffer);
 309                 if (ret != idx) {
 310                         debug("Error reading data (got %d)\n", ret);
 311                         return -1;
 312                 }
 313                 startsect += idx;
 314                 idx *= mydata->sect_size;
 315                 buffer += idx;
 316                 size -= idx;
 317         }
 318         if (size) {
 319                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 320
 321                 ret = disk_read(startsect, 1, tmpbuf);
 322                 if (ret != 1) {
 323                         debug("Error reading data (got %d)\n", ret);
 324                         return -1;
 325                 }
 326
 327                 memcpy(buffer, tmpbuf, size);
 328         }
 329
 330         return 0;
 331 }
 332
 333 /*
 334  * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
 335  * into 'buffer'.
 336  * Return the number of bytes read or -1 on fatal errors.
 337  */
 338 __u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
 339         __aligned(ARCH_DMA_MINALIGN);
 340
 341 static long
 342 get_contents(fsdata *mydata, dir_entry *dentptr, unsigned long pos,
 343              __u8 *buffer, unsigned long maxsize)
 344 {
 345         unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
 346         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 347         __u32 curclust = START(dentptr);
 348         __u32 endclust, newclust;
 349         unsigned long actsize;
 350
 351         debug("Filesize: %ld bytes\n", filesize);
 352
 353         if (pos >= filesize) {
 354                 debug("Read position past EOF: %lu\n", pos);
 355                 return gotsize;
 356         }
 357
 358         if (maxsize > 0 && filesize > pos + maxsize)
 359                 filesize = pos + maxsize;
 360
 361         debug("%ld bytes\n", filesize);
 362
 363         actsize = bytesperclust;
 364
 365         /* go to cluster at pos */
 366         while (actsize <= pos) {
 367                 curclust = get_fatent(mydata, curclust);
 368                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 369                         debug("curclust: 0x%x\n", curclust);
 370                         debug("Invalid FAT entry\n");
 371                         return gotsize;
 372                 }
 373                 actsize += bytesperclust;
 374         }
 375
 376         /* actsize > pos */
 377         actsize -= bytesperclust;
 378         filesize -= actsize;
 379         pos -= actsize;
 380
 381         /* align to beginning of next cluster if any */
 382         if (pos) {
 383                 actsize = min(filesize, bytesperclust);
 384                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 385                                 (int)actsize) != 0) {
 386                         printf("Error reading cluster\n");
 387                         return -1;
 388                 }
 389                 filesize -= actsize;
 390                 actsize -= pos;
 391                 memcpy(buffer, get_contents_vfatname_block + pos, actsize);
 392                 gotsize += actsize;
 393                 if (!filesize)
 394                         return gotsize;
 395                 buffer += actsize;
 396
 397                 curclust = get_fatent(mydata, curclust);
 398                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 399                         debug("curclust: 0x%x\n", curclust);
 400                         debug("Invalid FAT entry\n");
 401                         return gotsize;
 402                 }
 403         }
 404
 405         actsize = bytesperclust;
 406         endclust = curclust;
 407
 408         do {
 409                 /* search for consecutive clusters */
 410                 while (actsize < filesize) {
 411                         newclust = get_fatent(mydata, endclust);
 412                         if ((newclust - 1) != endclust)
 413                                 goto getit;
 414                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 415                                 debug("curclust: 0x%x\n", newclust);
 416                                 debug("Invalid FAT entry\n");
 417                                 return gotsize;
 418                         }
 419                         endclust = newclust;
 420                         actsize += bytesperclust;
 421                 }
 422
 423                 /* get remaining bytes */
 424                 actsize = filesize;
 425                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 426                         printf("Error reading cluster\n");
 427                         return -1;
 428                 }
 429                 gotsize += actsize;
 430                 return gotsize;
 431 getit:
 432                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 433                         printf("Error reading cluster\n");
 434                         return -1;
 435                 }
 436                 gotsize += (int)actsize;
 437                 filesize -= actsize;
 438                 buffer += actsize;
 439
 440                 curclust = get_fatent(mydata, endclust);
 441                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 442                         debug("curclust: 0x%x\n", curclust);
 443                         printf("Invalid FAT entry\n");
 444                         return gotsize;
 445                 }
 446                 actsize = bytesperclust;
 447                 endclust = curclust;
 448         } while (1);
 449 }
 450
 451 /*
 452  * Extract the file name information from 'slotptr' into 'l_name',
 453  * starting at l_name[*idx].
 454  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 455  */
 456 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
 457 {
 458         int j;
 459
 460         for (j = 0; j <= 8; j += 2) {
 461                 l_name[*idx] = slotptr->name0_4[j];
 462                 if (l_name[*idx] == 0x00)
 463                         return 1;
 464                 (*idx)++;
 465         }
 466         for (j = 0; j <= 10; j += 2) {
 467                 l_name[*idx] = slotptr->name5_10[j];
 468                 if (l_name[*idx] == 0x00)
 469                         return 1;
 470                 (*idx)++;
 471         }
 472         for (j = 0; j <= 2; j += 2) {
 473                 l_name[*idx] = slotptr->name11_12[j];
 474                 if (l_name[*idx] == 0x00)
 475                         return 1;
 476                 (*idx)++;
 477         }
 478
 479         return 0;
 480 }
 481
 482 /*
 483  * Extract the full long filename starting at 'retdent' (which is really
 484  * a slot) into 'l_name'. If successful also copy the real directory entry
 485  * into 'retdent'
 486  * Return 0 on success, -1 otherwise.
 487  */
 488 static int
 489 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 490              dir_entry *retdent, char *l_name)
 491 {
 492         dir_entry *realdent;
 493         dir_slot *slotptr = (dir_slot *)retdent;
 494         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 495                                                         PREFETCH_BLOCKS :
 496                                                         mydata->clust_size);
 497         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 498         int idx = 0;
 499
 500         if (counter > VFAT_MAXSEQ) {
 501                 debug("Error: VFAT name is too long\n");
 502                 return -1;
 503         }
 504
 505         while ((__u8 *)slotptr < buflimit) {
 506                 if (counter == 0)
 507                         break;
 508                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 509                         return -1;
 510                 slotptr++;
 511                 counter--;
 512         }
 513
 514         if ((__u8 *)slotptr >= buflimit) {
 515                 dir_slot *slotptr2;
 516
 517                 if (curclust == 0)
 518                         return -1;
 519                 curclust = get_fatent(mydata, curclust);
 520                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 521                         debug("curclust: 0x%x\n", curclust);
 522                         printf("Invalid FAT entry\n");
 523                         return -1;
 524                 }
 525
 526                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 527                                 mydata->clust_size * mydata->sect_size) != 0) {
 528                         debug("Error: reading directory block\n");
 529                         return -1;
 530                 }
 531
 532                 slotptr2 = (dir_slot *)get_contents_vfatname_block;
 533                 while (counter > 0) {
 534                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 535                             & 0xff) != counter)
 536                                 return -1;
 537                         slotptr2++;
 538                         counter--;
 539                 }
 540
 541                 /* Save the real directory entry */
 542                 realdent = (dir_entry *)slotptr2;
 543                 while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
 544                         slotptr2--;
 545                         slot2str(slotptr2, l_name, &idx);
 546                 }
 547         } else {
 548                 /* Save the real directory entry */
 549                 realdent = (dir_entry *)slotptr;
 550         }
 551
 552         do {
 553                 slotptr--;
 554                 if (slot2str(slotptr, l_name, &idx))
 555                         break;
 556         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 557
 558         l_name[idx] = '\0';
 559         if (*l_name == DELETED_FLAG)
 560                 *l_name = '\0';
 561         else if (*l_name == aRING)
 562                 *l_name = DELETED_FLAG;
 563         downcase(l_name);
 564
 565         /* Return the real directory entry */
 566         memcpy(retdent, realdent, sizeof(dir_entry));
 567
 568         return 0;
 569 }
 570
 571 /* Calculate short name checksum */
 572 static __u8 mkcksum(const char name[8], const char ext[3])
 573 {
 574         int i;
 575
 576         __u8 ret = 0;
 577
 578         for (i = 0; i < 8; i++)
 579                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
 580         for (i = 0; i < 3; i++)
 581                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
 582
 583         return ret;
 584 }
 585
 586 /*
 587  * Get the directory entry associated with 'filename' from the directory
 588  * starting at 'startsect'
 589  */
 590 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
 591         __aligned(ARCH_DMA_MINALIGN);
 592
 593 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
 594                                   char *filename, dir_entry *retdent,
 595                                   int dols)
 596 {
 597         __u16 prevcksum = 0xffff;
 598         __u32 curclust = START(retdent);
 599         int files = 0, dirs = 0;
 600
 601         debug("get_dentfromdir: %s\n", filename);
 602
 603         while (1) {
 604                 dir_entry *dentptr;
 605
 606                 int i;
 607
 608                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 609                                 mydata->clust_size * mydata->sect_size) != 0) {
 610                         debug("Error: reading directory block\n");
 611                         return NULL;
 612                 }
 613
 614                 dentptr = (dir_entry *)get_dentfromdir_block;
 615
 616                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 617                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 618
 619                         l_name[0] = '\0';
 620                         if (dentptr->name[0] == DELETED_FLAG) {
 621                                 dentptr++;
 622                                 continue;
 623                         }
 624                         if ((dentptr->attr & ATTR_VOLUME)) {
 625                                 if (vfat_enabled &&
 626                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 627                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 628                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 629                                         get_vfatname(mydata, curclust,
 630                                                      get_dentfromdir_block,
 631                                                      dentptr, l_name);
 632                                         if (dols) {
 633                                                 int isdir;
 634                                                 char dirc;
 635                                                 int doit = 0;
 636
 637                                                 isdir = (dentptr->attr & ATTR_DIR);
 638
 639                                                 if (isdir) {
 640                                                         dirs++;
 641                                                         dirc = '/';
 642                                                         doit = 1;
 643                                                 } else {
 644                                                         dirc = ' ';
 645                                                         if (l_name[0] != 0) {
 646                                                                 files++;
 647                                                                 doit = 1;
 648                                                         }
 649                                                 }
 650                                                 if (doit) {
 651                                                         if (dirc == ' ') {
 652                                                                 printf(" %8ld   %s%c\n",
 653                                                                         (long)FAT2CPU32(dentptr->size),
 654                                                                         l_name,
 655                                                                         dirc);
 656                                                         } else {
 657                                                                 printf("            %s%c\n",
 658                                                                         l_name,
 659                                                                         dirc);
 660                                                         }
 661                                                 }
 662                                                 dentptr++;
 663                                                 continue;
 664                                         }
 665                                         debug("vfatname: |%s|\n", l_name);
 666                                 } else {
 667                                         /* Volume label or VFAT entry */
 668                                         dentptr++;
 669                                         continue;
 670                                 }
 671                         }
 672                         if (dentptr->name[0] == 0) {
 673                                 if (dols) {
 674                                         printf("\n%d file(s), %d dir(s)\n\n",
 675                                                 files, dirs);
 676                                 }
 677                                 debug("Dentname == NULL - %d\n", i);
 678                                 return NULL;
 679                         }
 680                         if (vfat_enabled) {
 681                                 __u8 csum = mkcksum(dentptr->name, dentptr->ext);
 682                                 if (dols && csum == prevcksum) {
 683                                         prevcksum = 0xffff;
 684                                         dentptr++;
 685                                         continue;
 686                                 }
 687                         }
 688
 689                         get_name(dentptr, s_name);
 690                         if (dols) {
 691                                 int isdir = (dentptr->attr & ATTR_DIR);
 692                                 char dirc;
 693                                 int doit = 0;
 694
 695                                 if (isdir) {
 696                                         dirs++;
 697                                         dirc = '/';
 698                                         doit = 1;
 699                                 } else {
 700                                         dirc = ' ';
 701                                         if (s_name[0] != 0) {
 702                                                 files++;
 703                                                 doit = 1;
 704                                         }
 705                                 }
 706
 707                                 if (doit) {
 708                                         if (dirc == ' ') {
 709                                                 printf(" %8ld   %s%c\n",
 710                                                         (long)FAT2CPU32(dentptr->size),
 711                                                         s_name, dirc);
 712                                         } else {
 713                                                 printf("            %s%c\n",
 714                                                         s_name, dirc);
 715                                         }
 716                                 }
 717
 718                                 dentptr++;
 719                                 continue;
 720                         }
 721
 722                         if (strcmp(filename, s_name)
 723                             && strcmp(filename, l_name)) {
 724                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 725                                 dentptr++;
 726                                 continue;
 727                         }
 728
 729                         memcpy(retdent, dentptr, sizeof(dir_entry));
 730
 731                         debug("DentName: %s", s_name);
 732                         debug(", start: 0x%x", START(dentptr));
 733                         debug(", size:  0x%x %s\n",
 734                               FAT2CPU32(dentptr->size),
 735                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 736
 737                         return retdent;
 738                 }
 739
 740                 curclust = get_fatent(mydata, curclust);
 741                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 742                         debug("curclust: 0x%x\n", curclust);
 743                         printf("Invalid FAT entry\n");
 744                         return NULL;
 745                 }
 746         }
 747
 748         return NULL;
 749 }
 750
 751 /*
 752  * Read boot sector and volume info from a FAT filesystem
 753  */
 754 static int
 755 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 756 {
 757         __u8 *block;
 758         volume_info *vistart;
 759         int ret = 0;
 760
 761         if (cur_dev == NULL) {
 762                 debug("Error: no device selected\n");
 763                 return -1;
 764         }
 765
 766         block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
 767         if (block == NULL) {
 768                 debug("Error: allocating block\n");
 769                 return -1;
 770         }
 771
 772         if (disk_read(0, 1, block) < 0) {
 773                 debug("Error: reading block\n");
 774                 goto fail;
 775         }
 776
 777         memcpy(bs, block, sizeof(boot_sector));
 778         bs->reserved = FAT2CPU16(bs->reserved);
 779         bs->fat_length = FAT2CPU16(bs->fat_length);
 780         bs->secs_track = FAT2CPU16(bs->secs_track);
 781         bs->heads = FAT2CPU16(bs->heads);
 782         bs->total_sect = FAT2CPU32(bs->total_sect);
 783
 784         /* FAT32 entries */
 785         if (bs->fat_length == 0) {
 786                 /* Assume FAT32 */
 787                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 788                 bs->flags = FAT2CPU16(bs->flags);
 789                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 790                 bs->info_sector = FAT2CPU16(bs->info_sector);
 791                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 792                 vistart = (volume_info *)(block + sizeof(boot_sector));
 793                 *fatsize = 32;
 794         } else {
 795                 vistart = (volume_info *)&(bs->fat32_length);
 796                 *fatsize = 0;
 797         }
 798         memcpy(volinfo, vistart, sizeof(volume_info));
 799
 800         if (*fatsize == 32) {
 801                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 802                         goto exit;
 803         } else {
 804                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 805                         *fatsize = 12;
 806                         goto exit;
 807                 }
 808                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 809                         *fatsize = 16;
 810                         goto exit;
 811                 }
 812         }
 813
 814         debug("Error: broken fs_type sign\n");
 815 fail:
 816         ret = -1;
 817 exit:
 818         free(block);
 819         return ret;
 820 }
 821
 822 __u8 do_fat_read_at_block[MAX_CLUSTSIZE]
 823         __aligned(ARCH_DMA_MINALIGN);
 824
 825 long
 826 do_fat_read_at(const char *filename, unsigned long pos, void *buffer,
 827                unsigned long maxsize, int dols)
 828 {
 829         char fnamecopy[2048];
 830         boot_sector bs;
 831         volume_info volinfo;
 832         fsdata datablock;
 833         fsdata *mydata = &datablock;
 834         dir_entry *dentptr = NULL;
 835         __u16 prevcksum = 0xffff;
 836         char *subname = "";
 837         __u32 cursect;
 838         int idx, isdir = 0;
 839         int files = 0, dirs = 0;
 840         long ret = -1;
 841         int firsttime;
 842         __u32 root_cluster = 0;
 843         int rootdir_size = 0;
 844         int j;
 845
 846         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 847                 debug("Error: reading boot sector\n");
 848                 return -1;
 849         }
 850
 851         if (mydata->fatsize == 32) {
 852                 root_cluster = bs.root_cluster;
 853                 mydata->fatlength = bs.fat32_length;
 854         } else {
 855                 mydata->fatlength = bs.fat_length;
 856         }
 857
 858         mydata->fat_sect = bs.reserved;
 859
 860         cursect = mydata->rootdir_sect
 861                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 862
 863         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 864         mydata->clust_size = bs.cluster_size;
 865         if (mydata->sect_size != cur_part_info.blksz) {
 866                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 867                                 mydata->sect_size, cur_part_info.blksz);
 868                 return -1;
 869         }
 870
 871         if (mydata->fatsize == 32) {
 872                 mydata->data_begin = mydata->rootdir_sect -
 873                                         (mydata->clust_size * 2);
 874         } else {
 875                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 876                                  bs.dir_entries[0]) *
 877                                  sizeof(dir_entry)) /
 878                                  mydata->sect_size;
 879                 mydata->data_begin = mydata->rootdir_sect +
 880                                         rootdir_size -
 881                                         (mydata->clust_size * 2);
 882         }
 883
 884         mydata->fatbufnum = -1;
 885         mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
 886         if (mydata->fatbuf == NULL) {
 887                 debug("Error: allocating memory\n");
 888                 return -1;
 889         }
 890
 891         if (vfat_enabled)
 892                 debug("VFAT Support enabled\n");
 893
 894         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 895                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 896         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 897                "Data begins at: %d\n",
 898                root_cluster,
 899                mydata->rootdir_sect,
 900                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 901         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 902               mydata->clust_size);
 903
 904         /* "cwd" is always the root... */
 905         while (ISDIRDELIM(*filename))
 906                 filename++;
 907
 908         /* Make a copy of the filename and convert it to lowercase */
 909         strcpy(fnamecopy, filename);
 910         downcase(fnamecopy);
 911
 912         if (*fnamecopy == '\0') {
 913                 if (!dols)
 914                         goto exit;
 915
 916                 dols = LS_ROOT;
 917         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 918                 isdir = 1;
 919                 fnamecopy[idx] = '\0';
 920                 subname = fnamecopy + idx + 1;
 921
 922                 /* Handle multiple delimiters */
 923                 while (ISDIRDELIM(*subname))
 924                         subname++;
 925         } else if (dols) {
 926                 isdir = 1;
 927         }
 928
 929         j = 0;
 930         while (1) {
 931                 int i;
 932
 933                 if (j == 0) {
 934                         debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 935                                 cursect, mydata->clust_size, DIRENTSPERBLOCK);
 936
 937                         if (disk_read(cursect,
 938                                         (mydata->fatsize == 32) ?
 939                                         (mydata->clust_size) :
 940                                         PREFETCH_BLOCKS,
 941                                         do_fat_read_at_block) < 0) {
 942                                 debug("Error: reading rootdir block\n");
 943                                 goto exit;
 944                         }
 945
 946                         dentptr = (dir_entry *) do_fat_read_at_block;
 947                 }
 948
 949                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 950                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 951                         __u8 csum;
 952
 953                         l_name[0] = '\0';
 954                         if (dentptr->name[0] == DELETED_FLAG) {
 955                                 dentptr++;
 956                                 continue;
 957                         }
 958
 959                         if (vfat_enabled)
 960                                 csum = mkcksum(dentptr->name, dentptr->ext);
 961
 962                         if (dentptr->attr & ATTR_VOLUME) {
 963                                 if (vfat_enabled &&
 964                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 965                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 966                                         prevcksum =
 967                                                 ((dir_slot *)dentptr)->alias_checksum;
 968
 969                                         get_vfatname(mydata,
 970                                                      root_cluster,
 971                                                      do_fat_read_at_block,
 972                                                      dentptr, l_name);
 973
 974                                         if (dols == LS_ROOT) {
 975                                                 char dirc;
 976                                                 int doit = 0;
 977                                                 int isdir =
 978                                                         (dentptr->attr & ATTR_DIR);
 979
 980                                                 if (isdir) {
 981                                                         dirs++;
 982                                                         dirc = '/';
 983                                                         doit = 1;
 984                                                 } else {
 985                                                         dirc = ' ';
 986                                                         if (l_name[0] != 0) {
 987                                                                 files++;
 988                                                                 doit = 1;
 989                                                         }
 990                                                 }
 991                                                 if (doit) {
 992                                                         if (dirc == ' ') {
 993                                                                 printf(" %8ld   %s%c\n",
 994                                                                         (long)FAT2CPU32(dentptr->size),
 995                                                                         l_name,
 996                                                                         dirc);
 997                                                         } else {
 998                                                                 printf("            %s%c\n",
 999                                                                         l_name,
1000                                                                         dirc);
1001                                                         }
1002                                                 }
1003                                                 dentptr++;
1004                                                 continue;
1005                                         }
1006                                         debug("Rootvfatname: |%s|\n",
1007                                                l_name);
1008                                 } else {
1009                                         /* Volume label or VFAT entry */
1010                                         dentptr++;
1011                                         continue;
1012                                 }
1013                         } else if (dentptr->name[0] == 0) {
1014                                 debug("RootDentname == NULL - %d\n", i);
1015                                 if (dols == LS_ROOT) {
1016                                         printf("\n%d file(s), %d dir(s)\n\n",
1017                                                 files, dirs);
1018                                         ret = 0;
1019                                 }
1020                                 goto exit;
1021                         }
1022                         else if (vfat_enabled &&
1023                                  dols == LS_ROOT && csum == prevcksum) {
1024                                 prevcksum = 0xffff;
1025                                 dentptr++;
1026                                 continue;
1027                         }
1028
1029                         get_name(dentptr, s_name);
1030
1031                         if (dols == LS_ROOT) {
1032                                 int isdir = (dentptr->attr & ATTR_DIR);
1033                                 char dirc;
1034                                 int doit = 0;
1035
1036                                 if (isdir) {
1037                                         dirc = '/';
1038                                         if (s_name[0] != 0) {
1039                                                 dirs++;
1040                                                 doit = 1;
1041                                         }
1042                                 } else {
1043                                         dirc = ' ';
1044                                         if (s_name[0] != 0) {
1045                                                 files++;
1046                                                 doit = 1;
1047                                         }
1048                                 }
1049                                 if (doit) {
1050                                         if (dirc == ' ') {
1051                                                 printf(" %8ld   %s%c\n",
1052                                                         (long)FAT2CPU32(dentptr->size),
1053                                                         s_name, dirc);
1054                                         } else {
1055                                                 printf("            %s%c\n",
1056                                                         s_name, dirc);
1057                                         }
1058                                 }
1059                                 dentptr++;
1060                                 continue;
1061                         }
1062
1063                         if (strcmp(fnamecopy, s_name)
1064                             && strcmp(fnamecopy, l_name)) {
1065                                 debug("RootMismatch: |%s|%s|\n", s_name,
1066                                        l_name);
1067                                 dentptr++;
1068                                 continue;
1069                         }
1070
1071                         if (isdir && !(dentptr->attr & ATTR_DIR))
1072                                 goto exit;
1073
1074                         debug("RootName: %s", s_name);
1075                         debug(", start: 0x%x", START(dentptr));
1076                         debug(", size:  0x%x %s\n",
1077                                FAT2CPU32(dentptr->size),
1078                                isdir ? "(DIR)" : "");
1079
1080                         goto rootdir_done;      /* We got a match */
1081                 }
1082                 debug("END LOOP: j=%d   clust_size=%d\n", j,
1083                        mydata->clust_size);
1084
1085                 /*
1086                  * On FAT32 we must fetch the FAT entries for the next
1087                  * root directory clusters when a cluster has been
1088                  * completely processed.
1089                  */
1090                 ++j;
1091                 int rootdir_end = 0;
1092                 if (mydata->fatsize == 32) {
1093                         if (j == mydata->clust_size) {
1094                                 int nxtsect = 0;
1095                                 int nxt_clust = 0;
1096
1097                                 nxt_clust = get_fatent(mydata, root_cluster);
1098                                 rootdir_end = CHECK_CLUST(nxt_clust, 32);
1099
1100                                 nxtsect = mydata->data_begin +
1101                                         (nxt_clust * mydata->clust_size);
1102
1103                                 root_cluster = nxt_clust;
1104
1105                                 cursect = nxtsect;
1106                                 j = 0;
1107                         }
1108                 } else {
1109                         if (j == PREFETCH_BLOCKS)
1110                                 j = 0;
1111
1112                         rootdir_end = (++cursect - mydata->rootdir_sect >=
1113                                        rootdir_size);
1114                 }
1115
1116                 /* If end of rootdir reached */
1117                 if (rootdir_end) {
1118                         if (dols == LS_ROOT) {
1119                                 printf("\n%d file(s), %d dir(s)\n\n",
1120                                        files, dirs);
1121                                 ret = 0;
1122                         }
1123                         goto exit;
1124                 }
1125         }
1126 rootdir_done:
1127
1128         firsttime = 1;
1129
1130         while (isdir) {
1131                 int startsect = mydata->data_begin
1132                         + START(dentptr) * mydata->clust_size;
1133                 dir_entry dent;
1134                 char *nextname = NULL;
1135
1136                 dent = *dentptr;
1137                 dentptr = &dent;
1138
1139                 idx = dirdelim(subname);
1140
1141                 if (idx >= 0) {
1142                         subname[idx] = '\0';
1143                         nextname = subname + idx + 1;
1144                         /* Handle multiple delimiters */
1145                         while (ISDIRDELIM(*nextname))
1146                                 nextname++;
1147                         if (dols && *nextname == '\0')
1148                                 firsttime = 0;
1149                 } else {
1150                         if (dols && firsttime) {
1151                                 firsttime = 0;
1152                         } else {
1153                                 isdir = 0;
1154                         }
1155                 }
1156
1157                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1158                                      isdir ? 0 : dols) == NULL) {
1159                         if (dols && !isdir)
1160                                 ret = 0;
1161                         goto exit;
1162                 }
1163
1164                 if (isdir && !(dentptr->attr & ATTR_DIR))
1165                         goto exit;
1166
1167                 if (idx >= 0)
1168                         subname = nextname;
1169         }
1170
1171         ret = get_contents(mydata, dentptr, pos, buffer, maxsize);
1172         debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1173
1174 exit:
1175         free(mydata->fatbuf);
1176         return ret;
1177 }
1178
1179 long
1180 do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
1181 {
1182         return do_fat_read_at(filename, 0, buffer, maxsize, dols);
1183 }
1184
1185 int file_fat_detectfs(void)
1186 {
1187         boot_sector bs;
1188         volume_info volinfo;
1189         int fatsize;
1190         char vol_label[12];
1191
1192         if (cur_dev == NULL) {
1193                 printf("No current device\n");
1194                 return 1;
1195         }
1196
1197 #if defined(CONFIG_CMD_IDE) || \
1198     defined(CONFIG_CMD_SATA) || \
1199     defined(CONFIG_CMD_SCSI) || \
1200     defined(CONFIG_CMD_USB) || \
1201     defined(CONFIG_MMC)
1202         printf("Interface:  ");
1203         switch (cur_dev->if_type) {
1204         case IF_TYPE_IDE:
1205                 printf("IDE");
1206                 break;
1207         case IF_TYPE_SATA:
1208                 printf("SATA");
1209                 break;
1210         case IF_TYPE_SCSI:
1211                 printf("SCSI");
1212                 break;
1213         case IF_TYPE_ATAPI:
1214                 printf("ATAPI");
1215                 break;
1216         case IF_TYPE_USB:
1217                 printf("USB");
1218                 break;
1219         case IF_TYPE_DOC:
1220                 printf("DOC");
1221                 break;
1222         case IF_TYPE_MMC:
1223                 printf("MMC");
1224                 break;
1225         default:
1226                 printf("Unknown");
1227         }
1228
1229         printf("\n  Device %d: ", cur_dev->dev);
1230         dev_print(cur_dev);
1231 #endif
1232
1233         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1234                 printf("\nNo valid FAT fs found\n");
1235                 return 1;
1236         }
1237
1238         memcpy(vol_label, volinfo.volume_label, 11);
1239         vol_label[11] = '\0';
1240         volinfo.fs_type[5] = '\0';
1241
1242         printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
1243
1244         return 0;
1245 }
1246
1247 int file_fat_ls(const char *dir)
1248 {
1249         return do_fat_read(dir, NULL, 0, LS_YES);
1250 }
1251
1252 long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
1253                       unsigned long maxsize)
1254 {
1255         printf("reading %s\n", filename);
1256         return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO);
1257 }
1258
1259 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1260 {
1261         return file_fat_read_at(filename, 0, buffer, maxsize);
1262 }