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