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  * SPDX-License-Identifier:     GPL-2.0+
  10  */
  11
  12 #include <common.h>
  13 #include <config.h>
  14 #include <exports.h>
  15 #include <fat.h>
  16 #include <asm/byteorder.h>
  17 #include <part.h>
  18 #include <malloc.h>
  19 #include <memalign.h>
  20 #include <linux/compiler.h>
  21 #include <linux/ctype.h>
  22
  23 #ifdef CONFIG_SUPPORT_VFAT
  24 static const int vfat_enabled = 1;
  25 #else
  26 static const int vfat_enabled = 0;
  27 #endif
  28
  29 /*
  30  * Convert a string to lowercase.
  31  */
  32 static void downcase(char *str)
  33 {
  34         while (*str != '\0') {
  35                 *str = tolower(*str);
  36                 str++;
  37         }
  38 }
  39
  40 static block_dev_desc_t *cur_dev;
  41 static disk_partition_t cur_part_info;
  42
  43 #define DOS_BOOT_MAGIC_OFFSET   0x1fe
  44 #define DOS_FS_TYPE_OFFSET      0x36
  45 #define DOS_FS32_TYPE_OFFSET    0x52
  46
  47 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
  48 {
  49         ulong ret;
  50
  51         if (!cur_dev || !cur_dev->block_read)
  52                 return -1;
  53
  54         ret = cur_dev->block_read(cur_dev, cur_part_info.start + block,
  55                                   nr_blocks, buf);
  56
  57         if (nr_blocks && ret == 0)
  58                 return -1;
  59
  60         return ret;
  61 }
  62
  63 int fat_set_blk_dev(block_dev_desc_t *dev_desc, disk_partition_t *info)
  64 {
  65         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
  66
  67         cur_dev = dev_desc;
  68         cur_part_info = *info;
  69
  70         /* Make sure it has a valid FAT header */
  71         if (disk_read(0, 1, buffer) != 1) {
  72                 cur_dev = NULL;
  73                 return -1;
  74         }
  75
  76         /* Check if it's actually a DOS volume */
  77         if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
  78                 cur_dev = NULL;
  79                 return -1;
  80         }
  81
  82         /* Check for FAT12/FAT16/FAT32 filesystem */
  83         if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
  84                 return 0;
  85         if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
  86                 return 0;
  87
  88         cur_dev = NULL;
  89         return -1;
  90 }
  91
  92 int fat_register_device(block_dev_desc_t *dev_desc, int part_no)
  93 {
  94         disk_partition_t info;
  95
  96         /* First close any currently found FAT filesystem */
  97         cur_dev = NULL;
  98
  99         /* Read the partition table, if present */
 100         if (get_partition_info(dev_desc, part_no, &info)) {
 101                 if (part_no != 0) {
 102                         printf("** Partition %d not valid on device %d **\n",
 103                                         part_no, dev_desc->dev);
 104                         return -1;
 105                 }
 106
 107                 info.start = 0;
 108                 info.size = dev_desc->lba;
 109                 info.blksz = dev_desc->blksz;
 110                 info.name[0] = 0;
 111                 info.type[0] = 0;
 112                 info.bootable = 0;
 113 #ifdef CONFIG_PARTITION_UUIDS
 114                 info.uuid[0] = 0;
 115 #endif
 116         }
 117
 118         return fat_set_blk_dev(dev_desc, &info);
 119 }
 120
 121 /*
 122  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 123  * Return index into string if found, -1 otherwise.
 124  */
 125 static int dirdelim(char *str)
 126 {
 127         char *start = str;
 128
 129         while (*str != '\0') {
 130                 if (ISDIRDELIM(*str))
 131                         return str - start;
 132                 str++;
 133         }
 134         return -1;
 135 }
 136
 137 /*
 138  * Extract zero terminated short name from a directory entry.
 139  */
 140 static void get_name(dir_entry *dirent, char *s_name)
 141 {
 142         char *ptr;
 143
 144         memcpy(s_name, dirent->name, 8);
 145         s_name[8] = '\0';
 146         ptr = s_name;
 147         while (*ptr && *ptr != ' ')
 148                 ptr++;
 149         if (dirent->ext[0] && dirent->ext[0] != ' ') {
 150                 *ptr = '.';
 151                 ptr++;
 152                 memcpy(ptr, dirent->ext, 3);
 153                 ptr[3] = '\0';
 154                 while (*ptr && *ptr != ' ')
 155                         ptr++;
 156         }
 157         *ptr = '\0';
 158         if (*s_name == DELETED_FLAG)
 159                 *s_name = '\0';
 160         else if (*s_name == aRING)
 161                 *s_name = DELETED_FLAG;
 162         downcase(s_name);
 163 }
 164
 165 /*
 166  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 167  * On failure 0x00 is returned.
 168  */
 169 static __u32 get_fatent(fsdata *mydata, __u32 entry)
 170 {
 171         __u32 bufnum;
 172         __u32 off16, offset;
 173         __u32 ret = 0x00;
 174         __u16 val1, val2;
 175
 176         switch (mydata->fatsize) {
 177         case 32:
 178                 bufnum = entry / FAT32BUFSIZE;
 179                 offset = entry - bufnum * FAT32BUFSIZE;
 180                 break;
 181         case 16:
 182                 bufnum = entry / FAT16BUFSIZE;
 183                 offset = entry - bufnum * FAT16BUFSIZE;
 184                 break;
 185         case 12:
 186                 bufnum = entry / FAT12BUFSIZE;
 187                 offset = entry - bufnum * FAT12BUFSIZE;
 188                 break;
 189
 190         default:
 191                 /* Unsupported FAT size */
 192                 return ret;
 193         }
 194
 195         debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
 196                mydata->fatsize, entry, entry, offset, offset);
 197
 198         /* Read a new block of FAT entries into the cache. */
 199         if (bufnum != mydata->fatbufnum) {
 200                 __u32 getsize = FATBUFBLOCKS;
 201                 __u8 *bufptr = mydata->fatbuf;
 202                 __u32 fatlength = mydata->fatlength;
 203                 __u32 startblock = bufnum * FATBUFBLOCKS;
 204
 205                 if (startblock + getsize > fatlength)
 206                         getsize = fatlength - startblock;
 207
 208                 startblock += mydata->fat_sect; /* Offset from start of disk */
 209
 210                 if (disk_read(startblock, getsize, bufptr) < 0) {
 211                         debug("Error reading FAT blocks\n");
 212                         return ret;
 213                 }
 214                 mydata->fatbufnum = bufnum;
 215         }
 216
 217         /* Get the actual entry from the table */
 218         switch (mydata->fatsize) {
 219         case 32:
 220                 ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
 221                 break;
 222         case 16:
 223                 ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
 224                 break;
 225         case 12:
 226                 off16 = (offset * 3) / 4;
 227
 228                 switch (offset & 0x3) {
 229                 case 0:
 230                         ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
 231                         ret &= 0xfff;
 232                         break;
 233                 case 1:
 234                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 235                         val1 &= 0xf000;
 236                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 237                         val2 &= 0x00ff;
 238                         ret = (val2 << 4) | (val1 >> 12);
 239                         break;
 240                 case 2:
 241                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 242                         val1 &= 0xff00;
 243                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 244                         val2 &= 0x000f;
 245                         ret = (val2 << 8) | (val1 >> 8);
 246                         break;
 247                 case 3:
 248                         ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 249                         ret = (ret & 0xfff0) >> 4;
 250                         break;
 251                 default:
 252                         break;
 253                 }
 254                 break;
 255         }
 256         debug("FAT%d: ret: %08x, offset: %04x\n",
 257                mydata->fatsize, ret, offset);
 258
 259         return ret;
 260 }
 261
 262 /*
 263  * Read at most 'size' bytes from the specified cluster into 'buffer'.
 264  * Return 0 on success, -1 otherwise.
 265  */
 266 static int
 267 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
 268 {
 269         __u32 idx = 0;
 270         __u32 startsect;
 271         int ret;
 272
 273         if (clustnum > 0) {
 274                 startsect = mydata->data_begin +
 275                                 clustnum * mydata->clust_size;
 276         } else {
 277                 startsect = mydata->rootdir_sect;
 278         }
 279
 280         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 281
 282         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 283                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 284
 285                 printf("FAT: Misaligned buffer address (%p)\n", buffer);
 286
 287                 while (size >= mydata->sect_size) {
 288                         ret = disk_read(startsect++, 1, tmpbuf);
 289                         if (ret != 1) {
 290                                 debug("Error reading data (got %d)\n", ret);
 291                                 return -1;
 292                         }
 293
 294                         memcpy(buffer, tmpbuf, mydata->sect_size);
 295                         buffer += mydata->sect_size;
 296                         size -= mydata->sect_size;
 297                 }
 298         } else {
 299                 idx = size / mydata->sect_size;
 300                 ret = disk_read(startsect, idx, buffer);
 301                 if (ret != idx) {
 302                         debug("Error reading data (got %d)\n", ret);
 303                         return -1;
 304                 }
 305                 startsect += idx;
 306                 idx *= mydata->sect_size;
 307                 buffer += idx;
 308                 size -= idx;
 309         }
 310         if (size) {
 311                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 312
 313                 ret = disk_read(startsect, 1, tmpbuf);
 314                 if (ret != 1) {
 315                         debug("Error reading data (got %d)\n", ret);
 316                         return -1;
 317                 }
 318
 319                 memcpy(buffer, tmpbuf, size);
 320         }
 321
 322         return 0;
 323 }
 324
 325 /*
 326  * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
 327  * into 'buffer'.
 328  * Update the number of bytes read in *gotsize or return -1 on fatal errors.
 329  */
 330 __u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
 331         __aligned(ARCH_DMA_MINALIGN);
 332
 333 static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
 334                         __u8 *buffer, loff_t maxsize, loff_t *gotsize)
 335 {
 336         loff_t filesize = FAT2CPU32(dentptr->size);
 337         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 338         __u32 curclust = START(dentptr);
 339         __u32 endclust, newclust;
 340         loff_t actsize;
 341
 342         *gotsize = 0;
 343         debug("Filesize: %llu bytes\n", filesize);
 344
 345         if (pos >= filesize) {
 346                 debug("Read position past EOF: %llu\n", pos);
 347                 return 0;
 348         }
 349
 350         if (maxsize > 0 && filesize > pos + maxsize)
 351                 filesize = pos + maxsize;
 352
 353         debug("%llu bytes\n", filesize);
 354
 355         actsize = bytesperclust;
 356
 357         /* go to cluster at pos */
 358         while (actsize <= pos) {
 359                 curclust = get_fatent(mydata, curclust);
 360                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 361                         debug("curclust: 0x%x\n", curclust);
 362                         debug("Invalid FAT entry\n");
 363                         return 0;
 364                 }
 365                 actsize += bytesperclust;
 366         }
 367
 368         /* actsize > pos */
 369         actsize -= bytesperclust;
 370         filesize -= actsize;
 371         pos -= actsize;
 372
 373         /* align to beginning of next cluster if any */
 374         if (pos) {
 375                 actsize = min(filesize, (loff_t)bytesperclust);
 376                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 377                                 (int)actsize) != 0) {
 378                         printf("Error reading cluster\n");
 379                         return -1;
 380                 }
 381                 filesize -= actsize;
 382                 actsize -= pos;
 383                 memcpy(buffer, get_contents_vfatname_block + pos, actsize);
 384                 *gotsize += actsize;
 385                 if (!filesize)
 386                         return 0;
 387                 buffer += actsize;
 388
 389                 curclust = get_fatent(mydata, curclust);
 390                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 391                         debug("curclust: 0x%x\n", curclust);
 392                         debug("Invalid FAT entry\n");
 393                         return 0;
 394                 }
 395         }
 396
 397         actsize = bytesperclust;
 398         endclust = curclust;
 399
 400         do {
 401                 /* search for consecutive clusters */
 402                 while (actsize < filesize) {
 403                         newclust = get_fatent(mydata, endclust);
 404                         if ((newclust - 1) != endclust)
 405                                 goto getit;
 406                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 407                                 debug("curclust: 0x%x\n", newclust);
 408                                 debug("Invalid FAT entry\n");
 409                                 return 0;
 410                         }
 411                         endclust = newclust;
 412                         actsize += bytesperclust;
 413                 }
 414
 415                 /* get remaining bytes */
 416                 actsize = filesize;
 417                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 418                         printf("Error reading cluster\n");
 419                         return -1;
 420                 }
 421                 *gotsize += actsize;
 422                 return 0;
 423 getit:
 424                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 425                         printf("Error reading cluster\n");
 426                         return -1;
 427                 }
 428                 *gotsize += (int)actsize;
 429                 filesize -= actsize;
 430                 buffer += actsize;
 431
 432                 curclust = get_fatent(mydata, endclust);
 433                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 434                         debug("curclust: 0x%x\n", curclust);
 435                         printf("Invalid FAT entry\n");
 436                         return 0;
 437                 }
 438                 actsize = bytesperclust;
 439                 endclust = curclust;
 440         } while (1);
 441 }
 442
 443 /*
 444  * Extract the file name information from 'slotptr' into 'l_name',
 445  * starting at l_name[*idx].
 446  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 447  */
 448 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
 449 {
 450         int j;
 451
 452         for (j = 0; j <= 8; j += 2) {
 453                 l_name[*idx] = slotptr->name0_4[j];
 454                 if (l_name[*idx] == 0x00)
 455                         return 1;
 456                 (*idx)++;
 457         }
 458         for (j = 0; j <= 10; j += 2) {
 459                 l_name[*idx] = slotptr->name5_10[j];
 460                 if (l_name[*idx] == 0x00)
 461                         return 1;
 462                 (*idx)++;
 463         }
 464         for (j = 0; j <= 2; j += 2) {
 465                 l_name[*idx] = slotptr->name11_12[j];
 466                 if (l_name[*idx] == 0x00)
 467                         return 1;
 468                 (*idx)++;
 469         }
 470
 471         return 0;
 472 }
 473
 474 /*
 475  * Extract the full long filename starting at 'retdent' (which is really
 476  * a slot) into 'l_name'. If successful also copy the real directory entry
 477  * into 'retdent'
 478  * Return 0 on success, -1 otherwise.
 479  */
 480 static int
 481 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 482              dir_entry *retdent, char *l_name)
 483 {
 484         dir_entry *realdent;
 485         dir_slot *slotptr = (dir_slot *)retdent;
 486         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 487                                                         PREFETCH_BLOCKS :
 488                                                         mydata->clust_size);
 489         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 490         int idx = 0;
 491
 492         if (counter > VFAT_MAXSEQ) {
 493                 debug("Error: VFAT name is too long\n");
 494                 return -1;
 495         }
 496
 497         while ((__u8 *)slotptr < buflimit) {
 498                 if (counter == 0)
 499                         break;
 500                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 501                         return -1;
 502                 slotptr++;
 503                 counter--;
 504         }
 505
 506         if ((__u8 *)slotptr >= buflimit) {
 507                 dir_slot *slotptr2;
 508
 509                 if (curclust == 0)
 510                         return -1;
 511                 curclust = get_fatent(mydata, curclust);
 512                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 513                         debug("curclust: 0x%x\n", curclust);
 514                         printf("Invalid FAT entry\n");
 515                         return -1;
 516                 }
 517
 518                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 519                                 mydata->clust_size * mydata->sect_size) != 0) {
 520                         debug("Error: reading directory block\n");
 521                         return -1;
 522                 }
 523
 524                 slotptr2 = (dir_slot *)get_contents_vfatname_block;
 525                 while (counter > 0) {
 526                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 527                             & 0xff) != counter)
 528                                 return -1;
 529                         slotptr2++;
 530                         counter--;
 531                 }
 532
 533                 /* Save the real directory entry */
 534                 realdent = (dir_entry *)slotptr2;
 535                 while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
 536                         slotptr2--;
 537                         slot2str(slotptr2, l_name, &idx);
 538                 }
 539         } else {
 540                 /* Save the real directory entry */
 541                 realdent = (dir_entry *)slotptr;
 542         }
 543
 544         do {
 545                 slotptr--;
 546                 if (slot2str(slotptr, l_name, &idx))
 547                         break;
 548         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 549
 550         l_name[idx] = '\0';
 551         if (*l_name == DELETED_FLAG)
 552                 *l_name = '\0';
 553         else if (*l_name == aRING)
 554                 *l_name = DELETED_FLAG;
 555         downcase(l_name);
 556
 557         /* Return the real directory entry */
 558         memcpy(retdent, realdent, sizeof(dir_entry));
 559
 560         return 0;
 561 }
 562
 563 /* Calculate short name checksum */
 564 static __u8 mkcksum(const char name[8], const char ext[3])
 565 {
 566         int i;
 567
 568         __u8 ret = 0;
 569
 570         for (i = 0; i < 8; i++)
 571                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
 572         for (i = 0; i < 3; i++)
 573                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
 574
 575         return ret;
 576 }
 577
 578 /*
 579  * Get the directory entry associated with 'filename' from the directory
 580  * starting at 'startsect'
 581  */
 582 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
 583         __aligned(ARCH_DMA_MINALIGN);
 584
 585 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
 586                                   char *filename, dir_entry *retdent,
 587                                   int dols)
 588 {
 589         __u16 prevcksum = 0xffff;
 590         __u32 curclust = START(retdent);
 591         int files = 0, dirs = 0;
 592
 593         debug("get_dentfromdir: %s\n", filename);
 594
 595         while (1) {
 596                 dir_entry *dentptr;
 597
 598                 int i;
 599
 600                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 601                                 mydata->clust_size * mydata->sect_size) != 0) {
 602                         debug("Error: reading directory block\n");
 603                         return NULL;
 604                 }
 605
 606                 dentptr = (dir_entry *)get_dentfromdir_block;
 607
 608                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 609                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 610
 611                         l_name[0] = '\0';
 612                         if (dentptr->name[0] == DELETED_FLAG) {
 613                                 dentptr++;
 614                                 continue;
 615                         }
 616                         if ((dentptr->attr & ATTR_VOLUME)) {
 617                                 if (vfat_enabled &&
 618                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 619                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 620                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 621                                         get_vfatname(mydata, curclust,
 622                                                      get_dentfromdir_block,
 623                                                      dentptr, l_name);
 624                                         if (dols) {
 625                                                 int isdir;
 626                                                 char dirc;
 627                                                 int doit = 0;
 628
 629                                                 isdir = (dentptr->attr & ATTR_DIR);
 630
 631                                                 if (isdir) {
 632                                                         dirs++;
 633                                                         dirc = '/';
 634                                                         doit = 1;
 635                                                 } else {
 636                                                         dirc = ' ';
 637                                                         if (l_name[0] != 0) {
 638                                                                 files++;
 639                                                                 doit = 1;
 640                                                         }
 641                                                 }
 642                                                 if (doit) {
 643                                                         if (dirc == ' ') {
 644                                                                 printf(" %8u   %s%c\n",
 645                                                                        FAT2CPU32(dentptr->size),
 646                                                                         l_name,
 647                                                                         dirc);
 648                                                         } else {
 649                                                                 printf("            %s%c\n",
 650                                                                         l_name,
 651                                                                         dirc);
 652                                                         }
 653                                                 }
 654                                                 dentptr++;
 655                                                 continue;
 656                                         }
 657                                         debug("vfatname: |%s|\n", l_name);
 658                                 } else {
 659                                         /* Volume label or VFAT entry */
 660                                         dentptr++;
 661                                         continue;
 662                                 }
 663                         }
 664                         if (dentptr->name[0] == 0) {
 665                                 if (dols) {
 666                                         printf("\n%d file(s), %d dir(s)\n\n",
 667                                                 files, dirs);
 668                                 }
 669                                 debug("Dentname == NULL - %d\n", i);
 670                                 return NULL;
 671                         }
 672                         if (vfat_enabled) {
 673                                 __u8 csum = mkcksum(dentptr->name, dentptr->ext);
 674                                 if (dols && csum == prevcksum) {
 675                                         prevcksum = 0xffff;
 676                                         dentptr++;
 677                                         continue;
 678                                 }
 679                         }
 680
 681                         get_name(dentptr, s_name);
 682                         if (dols) {
 683                                 int isdir = (dentptr->attr & ATTR_DIR);
 684                                 char dirc;
 685                                 int doit = 0;
 686
 687                                 if (isdir) {
 688                                         dirs++;
 689                                         dirc = '/';
 690                                         doit = 1;
 691                                 } else {
 692                                         dirc = ' ';
 693                                         if (s_name[0] != 0) {
 694                                                 files++;
 695                                                 doit = 1;
 696                                         }
 697                                 }
 698
 699                                 if (doit) {
 700                                         if (dirc == ' ') {
 701                                                 printf(" %8u   %s%c\n",
 702                                                        FAT2CPU32(dentptr->size),
 703                                                         s_name, dirc);
 704                                         } else {
 705                                                 printf("            %s%c\n",
 706                                                         s_name, dirc);
 707                                         }
 708                                 }
 709
 710                                 dentptr++;
 711                                 continue;
 712                         }
 713
 714                         if (strcmp(filename, s_name)
 715                             && strcmp(filename, l_name)) {
 716                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 717                                 dentptr++;
 718                                 continue;
 719                         }
 720
 721                         memcpy(retdent, dentptr, sizeof(dir_entry));
 722
 723                         debug("DentName: %s", s_name);
 724                         debug(", start: 0x%x", START(dentptr));
 725                         debug(", size:  0x%x %s\n",
 726                               FAT2CPU32(dentptr->size),
 727                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 728
 729                         return retdent;
 730                 }
 731
 732                 curclust = get_fatent(mydata, curclust);
 733                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 734                         debug("curclust: 0x%x\n", curclust);
 735                         printf("Invalid FAT entry\n");
 736                         return NULL;
 737                 }
 738         }
 739
 740         return NULL;
 741 }
 742
 743 /*
 744  * Read boot sector and volume info from a FAT filesystem
 745  */
 746 static int
 747 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 748 {
 749         __u8 *block;
 750         volume_info *vistart;
 751         int ret = 0;
 752
 753         if (cur_dev == NULL) {
 754                 debug("Error: no device selected\n");
 755                 return -1;
 756         }
 757
 758         block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
 759         if (block == NULL) {
 760                 debug("Error: allocating block\n");
 761                 return -1;
 762         }
 763
 764         if (disk_read(0, 1, block) < 0) {
 765                 debug("Error: reading block\n");
 766                 goto fail;
 767         }
 768
 769         memcpy(bs, block, sizeof(boot_sector));
 770         bs->reserved = FAT2CPU16(bs->reserved);
 771         bs->fat_length = FAT2CPU16(bs->fat_length);
 772         bs->secs_track = FAT2CPU16(bs->secs_track);
 773         bs->heads = FAT2CPU16(bs->heads);
 774         bs->total_sect = FAT2CPU32(bs->total_sect);
 775
 776         /* FAT32 entries */
 777         if (bs->fat_length == 0) {
 778                 /* Assume FAT32 */
 779                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 780                 bs->flags = FAT2CPU16(bs->flags);
 781                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 782                 bs->info_sector = FAT2CPU16(bs->info_sector);
 783                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 784                 vistart = (volume_info *)(block + sizeof(boot_sector));
 785                 *fatsize = 32;
 786         } else {
 787                 vistart = (volume_info *)&(bs->fat32_length);
 788                 *fatsize = 0;
 789         }
 790         memcpy(volinfo, vistart, sizeof(volume_info));
 791
 792         if (*fatsize == 32) {
 793                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 794                         goto exit;
 795         } else {
 796                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 797                         *fatsize = 12;
 798                         goto exit;
 799                 }
 800                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 801                         *fatsize = 16;
 802                         goto exit;
 803                 }
 804         }
 805
 806         debug("Error: broken fs_type sign\n");
 807 fail:
 808         ret = -1;
 809 exit:
 810         free(block);
 811         return ret;
 812 }
 813
 814 __u8 do_fat_read_at_block[MAX_CLUSTSIZE]
 815         __aligned(ARCH_DMA_MINALIGN);
 816
 817 int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
 818                    loff_t maxsize, int dols, int dogetsize, loff_t *size)
 819 {
 820         char fnamecopy[2048];
 821         boot_sector bs;
 822         volume_info volinfo;
 823         fsdata datablock;
 824         fsdata *mydata = &datablock;
 825         dir_entry *dentptr = NULL;
 826         __u16 prevcksum = 0xffff;
 827         char *subname = "";
 828         __u32 cursect;
 829         int idx, isdir = 0;
 830         int files = 0, dirs = 0;
 831         int ret = -1;
 832         int firsttime;
 833         __u32 root_cluster = 0;
 834         __u32 read_blk;
 835         int rootdir_size = 0;
 836         int buffer_blk_cnt;
 837         int do_read;
 838         __u8 *dir_ptr;
 839
 840         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 841                 debug("Error: reading boot sector\n");
 842                 return -1;
 843         }
 844
 845         if (mydata->fatsize == 32) {
 846                 root_cluster = bs.root_cluster;
 847                 mydata->fatlength = bs.fat32_length;
 848         } else {
 849                 mydata->fatlength = bs.fat_length;
 850         }
 851
 852         mydata->fat_sect = bs.reserved;
 853
 854         cursect = mydata->rootdir_sect
 855                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 856
 857         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 858         mydata->clust_size = bs.cluster_size;
 859         if (mydata->sect_size != cur_part_info.blksz) {
 860                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 861                                 mydata->sect_size, cur_part_info.blksz);
 862                 return -1;
 863         }
 864
 865         if (mydata->fatsize == 32) {
 866                 mydata->data_begin = mydata->rootdir_sect -
 867                                         (mydata->clust_size * 2);
 868         } else {
 869                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 870                                  bs.dir_entries[0]) *
 871                                  sizeof(dir_entry)) /
 872                                  mydata->sect_size;
 873                 mydata->data_begin = mydata->rootdir_sect +
 874                                         rootdir_size -
 875                                         (mydata->clust_size * 2);
 876         }
 877
 878         mydata->fatbufnum = -1;
 879         mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
 880         if (mydata->fatbuf == NULL) {
 881                 debug("Error: allocating memory\n");
 882                 return -1;
 883         }
 884
 885         if (vfat_enabled)
 886                 debug("VFAT Support enabled\n");
 887
 888         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 889                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 890         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 891                "Data begins at: %d\n",
 892                root_cluster,
 893                mydata->rootdir_sect,
 894                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 895         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 896               mydata->clust_size);
 897
 898         /* "cwd" is always the root... */
 899         while (ISDIRDELIM(*filename))
 900                 filename++;
 901
 902         /* Make a copy of the filename and convert it to lowercase */
 903         strcpy(fnamecopy, filename);
 904         downcase(fnamecopy);
 905
 906 root_reparse:
 907         if (*fnamecopy == '\0') {
 908                 if (!dols)
 909                         goto exit;
 910
 911                 dols = LS_ROOT;
 912         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 913                 isdir = 1;
 914                 fnamecopy[idx] = '\0';
 915                 subname = fnamecopy + idx + 1;
 916
 917                 /* Handle multiple delimiters */
 918                 while (ISDIRDELIM(*subname))
 919                         subname++;
 920         } else if (dols) {
 921                 isdir = 1;
 922         }
 923
 924         buffer_blk_cnt = 0;
 925         firsttime = 1;
 926         while (1) {
 927                 int i;
 928
 929                 if (mydata->fatsize == 32 || firsttime) {
 930                         dir_ptr = do_fat_read_at_block;
 931                         firsttime = 0;
 932                 } else {
 933                         /**
 934                          * FAT16 sector buffer modification:
 935                          * Each loop, the second buffered block is moved to
 936                          * the buffer begin, and two next sectors are read
 937                          * next to the previously moved one. So the sector
 938                          * buffer keeps always 3 sectors for fat16.
 939                          * And the current sector is the buffer second sector
 940                          * beside the "firsttime" read, when it is the first one.
 941                          *
 942                          * PREFETCH_BLOCKS is 2 for FAT16 == loop[0:1]
 943                          * n = computed root dir sector
 944                          * loop |  cursect-1  | cursect    | cursect+1  |
 945                          *   0  |  sector n+0 | sector n+1 | none       |
 946                          *   1  |  none       | sector n+0 | sector n+1 |
 947                          *   0  |  sector n+1 | sector n+2 | sector n+3 |
 948                          *   1  |  sector n+3 | ...
 949                         */
 950                         dir_ptr = (do_fat_read_at_block + mydata->sect_size);
 951                         memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
 952                 }
 953
 954                 do_read = 1;
 955
 956                 if (mydata->fatsize == 32 && buffer_blk_cnt)
 957                         do_read = 0;
 958
 959                 if (do_read) {
 960                         read_blk = (mydata->fatsize == 32) ?
 961                                     mydata->clust_size : PREFETCH_BLOCKS;
 962
 963                         debug("FAT read(sect=%d, cnt:%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 964                                 cursect, read_blk, mydata->clust_size, DIRENTSPERBLOCK);
 965
 966                         if (disk_read(cursect, read_blk, dir_ptr) < 0) {
 967                                 debug("Error: reading rootdir block\n");
 968                                 goto exit;
 969                         }
 970
 971                         dentptr = (dir_entry *)dir_ptr;
 972                 }
 973
 974                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 975                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 976                         __u8 csum;
 977
 978                         l_name[0] = '\0';
 979                         if (dentptr->name[0] == DELETED_FLAG) {
 980                                 dentptr++;
 981                                 continue;
 982                         }
 983
 984                         if (vfat_enabled)
 985                                 csum = mkcksum(dentptr->name, dentptr->ext);
 986
 987                         if (dentptr->attr & ATTR_VOLUME) {
 988                                 if (vfat_enabled &&
 989                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 990                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 991                                         prevcksum =
 992                                                 ((dir_slot *)dentptr)->alias_checksum;
 993
 994                                         get_vfatname(mydata,
 995                                                      root_cluster,
 996                                                      dir_ptr,
 997                                                      dentptr, l_name);
 998
 999                                         if (dols == LS_ROOT) {
1000                                                 char dirc;
1001                                                 int doit = 0;
1002                                                 int isdir =
1003                                                         (dentptr->attr & ATTR_DIR);
1004
1005                                                 if (isdir) {
1006                                                         dirs++;
1007                                                         dirc = '/';
1008                                                         doit = 1;
1009                                                 } else {
1010                                                         dirc = ' ';
1011                                                         if (l_name[0] != 0) {
1012                                                                 files++;
1013                                                                 doit = 1;
1014                                                         }
1015                                                 }
1016                                                 if (doit) {
1017                                                         if (dirc == ' ') {
1018                                                                 printf(" %8u   %s%c\n",
1019                                                                        FAT2CPU32(dentptr->size),
1020                                                                         l_name,
1021                                                                         dirc);
1022                                                         } else {
1023                                                                 printf("            %s%c\n",
1024                                                                         l_name,
1025                                                                         dirc);
1026                                                         }
1027                                                 }
1028                                                 dentptr++;
1029                                                 continue;
1030                                         }
1031                                         debug("Rootvfatname: |%s|\n",
1032                                                l_name);
1033                                 } else {
1034                                         /* Volume label or VFAT entry */
1035                                         dentptr++;
1036                                         continue;
1037                                 }
1038                         } else if (dentptr->name[0] == 0) {
1039                                 debug("RootDentname == NULL - %d\n", i);
1040                                 if (dols == LS_ROOT) {
1041                                         printf("\n%d file(s), %d dir(s)\n\n",
1042                                                 files, dirs);
1043                                         ret = 0;
1044                                 }
1045                                 goto exit;
1046                         }
1047                         else if (vfat_enabled &&
1048                                  dols == LS_ROOT && csum == prevcksum) {
1049                                 prevcksum = 0xffff;
1050                                 dentptr++;
1051                                 continue;
1052                         }
1053
1054                         get_name(dentptr, s_name);
1055
1056                         if (dols == LS_ROOT) {
1057                                 int isdir = (dentptr->attr & ATTR_DIR);
1058                                 char dirc;
1059                                 int doit = 0;
1060
1061                                 if (isdir) {
1062                                         dirc = '/';
1063                                         if (s_name[0] != 0) {
1064                                                 dirs++;
1065                                                 doit = 1;
1066                                         }
1067                                 } else {
1068                                         dirc = ' ';
1069                                         if (s_name[0] != 0) {
1070                                                 files++;
1071                                                 doit = 1;
1072                                         }
1073                                 }
1074                                 if (doit) {
1075                                         if (dirc == ' ') {
1076                                                 printf(" %8u   %s%c\n",
1077                                                        FAT2CPU32(dentptr->size),
1078                                                         s_name, dirc);
1079                                         } else {
1080                                                 printf("            %s%c\n",
1081                                                         s_name, dirc);
1082                                         }
1083                                 }
1084                                 dentptr++;
1085                                 continue;
1086                         }
1087
1088                         if (strcmp(fnamecopy, s_name)
1089                             && strcmp(fnamecopy, l_name)) {
1090                                 debug("RootMismatch: |%s|%s|\n", s_name,
1091                                        l_name);
1092                                 dentptr++;
1093                                 continue;
1094                         }
1095
1096                         if (isdir && !(dentptr->attr & ATTR_DIR))
1097                                 goto exit;
1098
1099                         debug("RootName: %s", s_name);
1100                         debug(", start: 0x%x", START(dentptr));
1101                         debug(", size:  0x%x %s\n",
1102                                FAT2CPU32(dentptr->size),
1103                                isdir ? "(DIR)" : "");
1104
1105                         goto rootdir_done;      /* We got a match */
1106                 }
1107                 debug("END LOOP: buffer_blk_cnt=%d   clust_size=%d\n", buffer_blk_cnt,
1108                        mydata->clust_size);
1109
1110                 /*
1111                  * On FAT32 we must fetch the FAT entries for the next
1112                  * root directory clusters when a cluster has been
1113                  * completely processed.
1114                  */
1115                 ++buffer_blk_cnt;
1116                 int rootdir_end = 0;
1117                 if (mydata->fatsize == 32) {
1118                         if (buffer_blk_cnt == mydata->clust_size) {
1119                                 int nxtsect = 0;
1120                                 int nxt_clust = 0;
1121
1122                                 nxt_clust = get_fatent(mydata, root_cluster);
1123                                 rootdir_end = CHECK_CLUST(nxt_clust, 32);
1124
1125                                 nxtsect = mydata->data_begin +
1126                                         (nxt_clust * mydata->clust_size);
1127
1128                                 root_cluster = nxt_clust;
1129
1130                                 cursect = nxtsect;
1131                                 buffer_blk_cnt = 0;
1132                         }
1133                 } else {
1134                         if (buffer_blk_cnt == PREFETCH_BLOCKS)
1135                                 buffer_blk_cnt = 0;
1136
1137                         rootdir_end = (++cursect - mydata->rootdir_sect >=
1138                                        rootdir_size);
1139                 }
1140
1141                 /* If end of rootdir reached */
1142                 if (rootdir_end) {
1143                         if (dols == LS_ROOT) {
1144                                 printf("\n%d file(s), %d dir(s)\n\n",
1145                                        files, dirs);
1146                                 *size = 0;
1147                         }
1148                         goto exit;
1149                 }
1150         }
1151 rootdir_done:
1152
1153         firsttime = 1;
1154
1155         while (isdir) {
1156                 int startsect = mydata->data_begin
1157                         + START(dentptr) * mydata->clust_size;
1158                 dir_entry dent;
1159                 char *nextname = NULL;
1160
1161                 dent = *dentptr;
1162                 dentptr = &dent;
1163
1164                 idx = dirdelim(subname);
1165
1166                 if (idx >= 0) {
1167                         subname[idx] = '\0';
1168                         nextname = subname + idx + 1;
1169                         /* Handle multiple delimiters */
1170                         while (ISDIRDELIM(*nextname))
1171                                 nextname++;
1172                         if (dols && *nextname == '\0')
1173                                 firsttime = 0;
1174                 } else {
1175                         if (dols && firsttime) {
1176                                 firsttime = 0;
1177                         } else {
1178                                 isdir = 0;
1179                         }
1180                 }
1181
1182                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1183                                      isdir ? 0 : dols) == NULL) {
1184                         if (dols && !isdir)
1185                                 *size = 0;
1186                         goto exit;
1187                 }
1188
1189                 if (isdir && !(dentptr->attr & ATTR_DIR))
1190                         goto exit;
1191
1192                 /*
1193                  * If we are looking for a directory, and found a directory
1194                  * type entry, and the entry is for the root directory (as
1195                  * denoted by a cluster number of 0), jump back to the start
1196                  * of the function, since at least on FAT12/16, the root dir
1197                  * lives in a hard-coded location and needs special handling
1198                  * to parse, rather than simply following the cluster linked
1199                  * list in the FAT, like other directories.
1200                  */
1201                 if (isdir && (dentptr->attr & ATTR_DIR) && !START(dentptr)) {
1202                         /*
1203                          * Modify the filename to remove the prefix that gets
1204                          * back to the root directory, so the initial root dir
1205                          * parsing code can continue from where we are without
1206                          * confusion.
1207                          */
1208                         strcpy(fnamecopy, nextname ?: "");
1209                         /*
1210                          * Set up state the same way as the function does when
1211                          * first started. This is required for the root dir
1212                          * parsing code operates in its expected environment.
1213                          */
1214                         subname = "";
1215                         cursect = mydata->rootdir_sect;
1216                         isdir = 0;
1217                         goto root_reparse;
1218                 }
1219
1220                 if (idx >= 0)
1221                         subname = nextname;
1222         }
1223
1224         if (dogetsize) {
1225                 *size = FAT2CPU32(dentptr->size);
1226                 ret = 0;
1227         } else {
1228                 ret = get_contents(mydata, dentptr, pos, buffer, maxsize, size);
1229         }
1230         debug("Size: %u, got: %llu\n", FAT2CPU32(dentptr->size), *size);
1231
1232 exit:
1233         free(mydata->fatbuf);
1234         return ret;
1235 }
1236
1237 int do_fat_read(const char *filename, void *buffer, loff_t maxsize, int dols,
1238                 loff_t *actread)
1239 {
1240         return do_fat_read_at(filename, 0, buffer, maxsize, dols, 0, actread);
1241 }
1242
1243 int file_fat_detectfs(void)
1244 {
1245         boot_sector bs;
1246         volume_info volinfo;
1247         int fatsize;
1248         char vol_label[12];
1249
1250         if (cur_dev == NULL) {
1251                 printf("No current device\n");
1252                 return 1;
1253         }
1254
1255 #if defined(CONFIG_CMD_IDE) || \
1256     defined(CONFIG_CMD_SATA) || \
1257     defined(CONFIG_CMD_SCSI) || \
1258     defined(CONFIG_CMD_USB) || \
1259     defined(CONFIG_MMC)
1260         printf("Interface:  ");
1261         switch (cur_dev->if_type) {
1262         case IF_TYPE_IDE:
1263                 printf("IDE");
1264                 break;
1265         case IF_TYPE_SATA:
1266                 printf("SATA");
1267                 break;
1268         case IF_TYPE_SCSI:
1269                 printf("SCSI");
1270                 break;
1271         case IF_TYPE_ATAPI:
1272                 printf("ATAPI");
1273                 break;
1274         case IF_TYPE_USB:
1275                 printf("USB");
1276                 break;
1277         case IF_TYPE_DOC:
1278                 printf("DOC");
1279                 break;
1280         case IF_TYPE_MMC:
1281                 printf("MMC");
1282                 break;
1283         default:
1284                 printf("Unknown");
1285         }
1286
1287         printf("\n  Device %d: ", cur_dev->dev);
1288         dev_print(cur_dev);
1289 #endif
1290
1291         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1292                 printf("\nNo valid FAT fs found\n");
1293                 return 1;
1294         }
1295
1296         memcpy(vol_label, volinfo.volume_label, 11);
1297         vol_label[11] = '\0';
1298         volinfo.fs_type[5] = '\0';
1299
1300         printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
1301
1302         return 0;
1303 }
1304
1305 int file_fat_ls(const char *dir)
1306 {
1307         loff_t size;
1308
1309         return do_fat_read(dir, NULL, 0, LS_YES, &size);
1310 }
1311
1312 int fat_exists(const char *filename)
1313 {
1314         int ret;
1315         loff_t size;
1316
1317         ret = do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, &size);
1318         return ret == 0;
1319 }
1320
1321 int fat_size(const char *filename, loff_t *size)
1322 {
1323         return do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, size);
1324 }
1325
1326 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
1327                      loff_t maxsize, loff_t *actread)
1328 {
1329         printf("reading %s\n", filename);
1330         return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO, 0,
1331                               actread);
1332 }
1333
1334 int file_fat_read(const char *filename, void *buffer, int maxsize)
1335 {
1336         loff_t actread;
1337         int ret;
1338
1339         ret =  file_fat_read_at(filename, 0, buffer, maxsize, &actread);
1340         if (ret)
1341                 return ret;
1342         else
1343                 return actread;
1344 }
1345
1346 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
1347                   loff_t *actread)
1348 {
1349         int ret;
1350
1351         ret = file_fat_read_at(filename, offset, buf, len, actread);
1352         if (ret)
1353                 printf("** Unable to read file %s **\n", filename);
1354
1355         return ret;
1356 }
1357
1358 void fat_close(void)
1359 {
1360 }