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