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 <blk.h>
  14 #include <config.h>
  15 #include <exports.h>
  16 #include <fat.h>
  17 #include <asm/byteorder.h>
  18 #include <part.h>
  19 #include <malloc.h>
  20 #include <memalign.h>
  21 #include <linux/compiler.h>
  22 #include <linux/ctype.h>
  23
  24 #ifdef CONFIG_SUPPORT_VFAT
  25 static const int vfat_enabled = 1;
  26 #else
  27 static const int vfat_enabled = 0;
  28 #endif
  29
  30 /*
  31  * Convert a string to lowercase.
  32  */
  33 static void downcase(char *str)
  34 {
  35         while (*str != '\0') {
  36                 *str = tolower(*str);
  37                 str++;
  38         }
  39 }
  40
  41 static struct blk_desc *cur_dev;
  42 static disk_partition_t cur_part_info;
  43
  44 #define DOS_BOOT_MAGIC_OFFSET   0x1fe
  45 #define DOS_FS_TYPE_OFFSET      0x36
  46 #define DOS_FS32_TYPE_OFFSET    0x52
  47
  48 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
  49 {
  50         ulong ret;
  51
  52         if (!cur_dev)
  53                 return -1;
  54
  55         ret = blk_dread(cur_dev, cur_part_info.start + block, 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(struct blk_desc *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(struct blk_desc *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 (part_get_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->devnum);
 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 #if CONFIG_IS_ENABLED(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 static int flush_dirty_fat_buffer(fsdata *mydata);
 166 #if !defined(CONFIG_FAT_WRITE)
 167 /* Stub for read only operation */
 168 int flush_dirty_fat_buffer(fsdata *mydata)
 169 {
 170         (void)(mydata);
 171         return 0;
 172 }
 173 #endif
 174
 175 /*
 176  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 177  * On failure 0x00 is returned.
 178  */
 179 static __u32 get_fatent(fsdata *mydata, __u32 entry)
 180 {
 181         __u32 bufnum;
 182         __u32 offset, off8;
 183         __u32 ret = 0x00;
 184
 185         if (CHECK_CLUST(entry, mydata->fatsize)) {
 186                 printf("Error: Invalid FAT entry: 0x%08x\n", entry);
 187                 return ret;
 188         }
 189
 190         switch (mydata->fatsize) {
 191         case 32:
 192                 bufnum = entry / FAT32BUFSIZE;
 193                 offset = entry - bufnum * FAT32BUFSIZE;
 194                 break;
 195         case 16:
 196                 bufnum = entry / FAT16BUFSIZE;
 197                 offset = entry - bufnum * FAT16BUFSIZE;
 198                 break;
 199         case 12:
 200                 bufnum = entry / FAT12BUFSIZE;
 201                 offset = entry - bufnum * FAT12BUFSIZE;
 202                 break;
 203
 204         default:
 205                 /* Unsupported FAT size */
 206                 return ret;
 207         }
 208
 209         debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
 210                mydata->fatsize, entry, entry, offset, offset);
 211
 212         /* Read a new block of FAT entries into the cache. */
 213         if (bufnum != mydata->fatbufnum) {
 214                 __u32 getsize = FATBUFBLOCKS;
 215                 __u8 *bufptr = mydata->fatbuf;
 216                 __u32 fatlength = mydata->fatlength;
 217                 __u32 startblock = bufnum * FATBUFBLOCKS;
 218
 219                 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
 220                 if (startblock + getsize > fatlength)
 221                         getsize = fatlength - startblock;
 222
 223                 startblock += mydata->fat_sect; /* Offset from start of disk */
 224
 225                 /* Write back the fatbuf to the disk */
 226                 if (flush_dirty_fat_buffer(mydata) < 0)
 227                         return -1;
 228
 229                 if (disk_read(startblock, getsize, bufptr) < 0) {
 230                         debug("Error reading FAT blocks\n");
 231                         return ret;
 232                 }
 233                 mydata->fatbufnum = bufnum;
 234         }
 235
 236         /* Get the actual entry from the table */
 237         switch (mydata->fatsize) {
 238         case 32:
 239                 ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
 240                 break;
 241         case 16:
 242                 ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
 243                 break;
 244         case 12:
 245                 off8 = (offset * 3) / 2;
 246                 /* fatbut + off8 may be unaligned, read in byte granularity */
 247                 ret = mydata->fatbuf[off8] + (mydata->fatbuf[off8 + 1] << 8);
 248
 249                 if (offset & 0x1)
 250                         ret >>= 4;
 251                 ret &= 0xfff;
 252         }
 253         debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
 254                mydata->fatsize, ret, entry, offset);
 255
 256         return ret;
 257 }
 258
 259 /*
 260  * Read at most 'size' bytes from the specified cluster into 'buffer'.
 261  * Return 0 on success, -1 otherwise.
 262  */
 263 static int
 264 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
 265 {
 266         __u32 idx = 0;
 267         __u32 startsect;
 268         int ret;
 269
 270         if (clustnum > 0) {
 271                 startsect = mydata->data_begin +
 272                                 clustnum * mydata->clust_size;
 273         } else {
 274                 startsect = mydata->rootdir_sect;
 275         }
 276
 277         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 278
 279         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 280                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 281
 282                 printf("FAT: Misaligned buffer address (%p)\n", buffer);
 283
 284                 while (size >= mydata->sect_size) {
 285                         ret = disk_read(startsect++, 1, tmpbuf);
 286                         if (ret != 1) {
 287                                 debug("Error reading data (got %d)\n", ret);
 288                                 return -1;
 289                         }
 290
 291                         memcpy(buffer, tmpbuf, mydata->sect_size);
 292                         buffer += mydata->sect_size;
 293                         size -= mydata->sect_size;
 294                 }
 295         } else {
 296                 idx = size / mydata->sect_size;
 297                 ret = disk_read(startsect, idx, buffer);
 298                 if (ret != idx) {
 299                         debug("Error reading data (got %d)\n", ret);
 300                         return -1;
 301                 }
 302                 startsect += idx;
 303                 idx *= mydata->sect_size;
 304                 buffer += idx;
 305                 size -= idx;
 306         }
 307         if (size) {
 308                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 309
 310                 ret = disk_read(startsect, 1, tmpbuf);
 311                 if (ret != 1) {
 312                         debug("Error reading data (got %d)\n", ret);
 313                         return -1;
 314                 }
 315
 316                 memcpy(buffer, tmpbuf, size);
 317         }
 318
 319         return 0;
 320 }
 321
 322 /*
 323  * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
 324  * into 'buffer'.
 325  * Update the number of bytes read in *gotsize or return -1 on fatal errors.
 326  */
 327 __u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
 328         __aligned(ARCH_DMA_MINALIGN);
 329
 330 static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
 331                         __u8 *buffer, loff_t maxsize, loff_t *gotsize)
 332 {
 333         loff_t filesize = FAT2CPU32(dentptr->size);
 334         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 335         __u32 curclust = START(dentptr);
 336         __u32 endclust, newclust;
 337         loff_t actsize;
 338
 339         *gotsize = 0;
 340         debug("Filesize: %llu bytes\n", filesize);
 341
 342         if (pos >= filesize) {
 343                 debug("Read position past EOF: %llu\n", pos);
 344                 return 0;
 345         }
 346
 347         if (maxsize > 0 && filesize > pos + maxsize)
 348                 filesize = pos + maxsize;
 349
 350         debug("%llu bytes\n", filesize);
 351
 352         actsize = bytesperclust;
 353
 354         /* go to cluster at pos */
 355         while (actsize <= pos) {
 356                 curclust = get_fatent(mydata, curclust);
 357                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 358                         debug("curclust: 0x%x\n", curclust);
 359                         debug("Invalid FAT entry\n");
 360                         return 0;
 361                 }
 362                 actsize += bytesperclust;
 363         }
 364
 365         /* actsize > pos */
 366         actsize -= bytesperclust;
 367         filesize -= actsize;
 368         pos -= actsize;
 369
 370         /* align to beginning of next cluster if any */
 371         if (pos) {
 372                 actsize = min(filesize, (loff_t)bytesperclust);
 373                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 374                                 (int)actsize) != 0) {
 375                         printf("Error reading cluster\n");
 376                         return -1;
 377                 }
 378                 filesize -= actsize;
 379                 actsize -= pos;
 380                 memcpy(buffer, get_contents_vfatname_block + pos, actsize);
 381                 *gotsize += actsize;
 382                 if (!filesize)
 383                         return 0;
 384                 buffer += actsize;
 385
 386                 curclust = get_fatent(mydata, curclust);
 387                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 388                         debug("curclust: 0x%x\n", curclust);
 389                         debug("Invalid FAT entry\n");
 390                         return 0;
 391                 }
 392         }
 393
 394         actsize = bytesperclust;
 395         endclust = curclust;
 396
 397         do {
 398                 /* search for consecutive clusters */
 399                 while (actsize < filesize) {
 400                         newclust = get_fatent(mydata, endclust);
 401                         if ((newclust - 1) != endclust)
 402                                 goto getit;
 403                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 404                                 debug("curclust: 0x%x\n", newclust);
 405                                 debug("Invalid FAT entry\n");
 406                                 return 0;
 407                         }
 408                         endclust = newclust;
 409                         actsize += bytesperclust;
 410                 }
 411
 412                 /* get remaining bytes */
 413                 actsize = filesize;
 414                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 415                         printf("Error reading cluster\n");
 416                         return -1;
 417                 }
 418                 *gotsize += actsize;
 419                 return 0;
 420 getit:
 421                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 422                         printf("Error reading cluster\n");
 423                         return -1;
 424                 }
 425                 *gotsize += (int)actsize;
 426                 filesize -= actsize;
 427                 buffer += actsize;
 428
 429                 curclust = get_fatent(mydata, endclust);
 430                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 431                         debug("curclust: 0x%x\n", curclust);
 432                         printf("Invalid FAT entry\n");
 433                         return 0;
 434                 }
 435                 actsize = bytesperclust;
 436                 endclust = curclust;
 437         } while (1);
 438 }
 439
 440 /*
 441  * Extract the file name information from 'slotptr' into 'l_name',
 442  * starting at l_name[*idx].
 443  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 444  */
 445 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
 446 {
 447         int j;
 448
 449         for (j = 0; j <= 8; j += 2) {
 450                 l_name[*idx] = slotptr->name0_4[j];
 451                 if (l_name[*idx] == 0x00)
 452                         return 1;
 453                 (*idx)++;
 454         }
 455         for (j = 0; j <= 10; j += 2) {
 456                 l_name[*idx] = slotptr->name5_10[j];
 457                 if (l_name[*idx] == 0x00)
 458                         return 1;
 459                 (*idx)++;
 460         }
 461         for (j = 0; j <= 2; j += 2) {
 462                 l_name[*idx] = slotptr->name11_12[j];
 463                 if (l_name[*idx] == 0x00)
 464                         return 1;
 465                 (*idx)++;
 466         }
 467
 468         return 0;
 469 }
 470
 471 /*
 472  * Extract the full long filename starting at 'retdent' (which is really
 473  * a slot) into 'l_name'. If successful also copy the real directory entry
 474  * into 'retdent'
 475  * Return 0 on success, -1 otherwise.
 476  */
 477 static int
 478 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 479              dir_entry *retdent, char *l_name)
 480 {
 481         dir_entry *realdent;
 482         dir_slot *slotptr = (dir_slot *)retdent;
 483         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 484                                                         PREFETCH_BLOCKS :
 485                                                         mydata->clust_size);
 486         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 487         int idx = 0;
 488
 489         if (counter > VFAT_MAXSEQ) {
 490                 debug("Error: VFAT name is too long\n");
 491                 return -1;
 492         }
 493
 494         while ((__u8 *)slotptr < buflimit) {
 495                 if (counter == 0)
 496                         break;
 497                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 498                         return -1;
 499                 slotptr++;
 500                 counter--;
 501         }
 502
 503         if ((__u8 *)slotptr >= buflimit) {
 504                 dir_slot *slotptr2;
 505
 506                 if (curclust == 0)
 507                         return -1;
 508                 curclust = get_fatent(mydata, curclust);
 509                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 510                         debug("curclust: 0x%x\n", curclust);
 511                         printf("Invalid FAT entry\n");
 512                         return -1;
 513                 }
 514
 515                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 516                                 mydata->clust_size * mydata->sect_size) != 0) {
 517                         debug("Error: reading directory block\n");
 518                         return -1;
 519                 }
 520
 521                 slotptr2 = (dir_slot *)get_contents_vfatname_block;
 522                 while (counter > 0) {
 523                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 524                             & 0xff) != counter)
 525                                 return -1;
 526                         slotptr2++;
 527                         counter--;
 528                 }
 529
 530                 /* Save the real directory entry */
 531                 realdent = (dir_entry *)slotptr2;
 532                 while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
 533                         slotptr2--;
 534                         slot2str(slotptr2, l_name, &idx);
 535                 }
 536         } else {
 537                 /* Save the real directory entry */
 538                 realdent = (dir_entry *)slotptr;
 539         }
 540
 541         do {
 542                 slotptr--;
 543                 if (slot2str(slotptr, l_name, &idx))
 544                         break;
 545         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 546
 547         l_name[idx] = '\0';
 548         if (*l_name == DELETED_FLAG)
 549                 *l_name = '\0';
 550         else if (*l_name == aRING)
 551                 *l_name = DELETED_FLAG;
 552         downcase(l_name);
 553
 554         /* Return the real directory entry */
 555         memcpy(retdent, realdent, sizeof(dir_entry));
 556
 557         return 0;
 558 }
 559
 560 /* Calculate short name checksum */
 561 static __u8 mkcksum(const char name[8], const char ext[3])
 562 {
 563         int i;
 564
 565         __u8 ret = 0;
 566
 567         for (i = 0; i < 8; i++)
 568                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
 569         for (i = 0; i < 3; i++)
 570                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
 571
 572         return ret;
 573 }
 574
 575 /*
 576  * Get the directory entry associated with 'filename' from the directory
 577  * starting at 'startsect'
 578  */
 579 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
 580         __aligned(ARCH_DMA_MINALIGN);
 581
 582 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
 583                                   char *filename, dir_entry *retdent,
 584                                   int dols)
 585 {
 586         __u16 prevcksum = 0xffff;
 587         __u32 curclust = START(retdent);
 588         int files = 0, dirs = 0;
 589
 590         debug("get_dentfromdir: %s\n", filename);
 591
 592         while (1) {
 593                 dir_entry *dentptr;
 594
 595                 int i;
 596
 597                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 598                                 mydata->clust_size * mydata->sect_size) != 0) {
 599                         debug("Error: reading directory block\n");
 600                         return NULL;
 601                 }
 602
 603                 dentptr = (dir_entry *)get_dentfromdir_block;
 604
 605                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 606                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 607
 608                         l_name[0] = '\0';
 609                         if (dentptr->name[0] == DELETED_FLAG) {
 610                                 dentptr++;
 611                                 continue;
 612                         }
 613                         if ((dentptr->attr & ATTR_VOLUME)) {
 614                                 if (vfat_enabled &&
 615                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 616                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 617                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 618                                         get_vfatname(mydata, curclust,
 619                                                      get_dentfromdir_block,
 620                                                      dentptr, l_name);
 621                                         if (dols) {
 622                                                 int isdir;
 623                                                 char dirc;
 624                                                 int doit = 0;
 625
 626                                                 isdir = (dentptr->attr & ATTR_DIR);
 627
 628                                                 if (isdir) {
 629                                                         dirs++;
 630                                                         dirc = '/';
 631                                                         doit = 1;
 632                                                 } else {
 633                                                         dirc = ' ';
 634                                                         if (l_name[0] != 0) {
 635                                                                 files++;
 636                                                                 doit = 1;
 637                                                         }
 638                                                 }
 639                                                 if (doit) {
 640                                                         if (dirc == ' ') {
 641                                                                 printf(" %8u   %s%c\n",
 642                                                                        FAT2CPU32(dentptr->size),
 643                                                                         l_name,
 644                                                                         dirc);
 645                                                         } else {
 646                                                                 printf("            %s%c\n",
 647                                                                         l_name,
 648                                                                         dirc);
 649                                                         }
 650                                                 }
 651                                                 dentptr++;
 652                                                 continue;
 653                                         }
 654                                         debug("vfatname: |%s|\n", l_name);
 655                                 } else {
 656                                         /* Volume label or VFAT entry */
 657                                         dentptr++;
 658                                         continue;
 659                                 }
 660                         }
 661                         if (dentptr->name[0] == 0) {
 662                                 if (dols) {
 663                                         printf("\n%d file(s), %d dir(s)\n\n",
 664                                                 files, dirs);
 665                                 }
 666                                 debug("Dentname == NULL - %d\n", i);
 667                                 return NULL;
 668                         }
 669                         if (vfat_enabled) {
 670                                 __u8 csum = mkcksum(dentptr->name, dentptr->ext);
 671                                 if (dols && csum == prevcksum) {
 672                                         prevcksum = 0xffff;
 673                                         dentptr++;
 674                                         continue;
 675                                 }
 676                         }
 677
 678                         get_name(dentptr, s_name);
 679                         if (dols) {
 680                                 int isdir = (dentptr->attr & ATTR_DIR);
 681                                 char dirc;
 682                                 int doit = 0;
 683
 684                                 if (isdir) {
 685                                         dirs++;
 686                                         dirc = '/';
 687                                         doit = 1;
 688                                 } else {
 689                                         dirc = ' ';
 690                                         if (s_name[0] != 0) {
 691                                                 files++;
 692                                                 doit = 1;
 693                                         }
 694                                 }
 695
 696                                 if (doit) {
 697                                         if (dirc == ' ') {
 698                                                 printf(" %8u   %s%c\n",
 699                                                        FAT2CPU32(dentptr->size),
 700                                                         s_name, dirc);
 701                                         } else {
 702                                                 printf("            %s%c\n",
 703                                                         s_name, dirc);
 704                                         }
 705                                 }
 706
 707                                 dentptr++;
 708                                 continue;
 709                         }
 710
 711                         if (strcmp(filename, s_name)
 712                             && strcmp(filename, l_name)) {
 713                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 714                                 dentptr++;
 715                                 continue;
 716                         }
 717
 718                         memcpy(retdent, dentptr, sizeof(dir_entry));
 719
 720                         debug("DentName: %s", s_name);
 721                         debug(", start: 0x%x", START(dentptr));
 722                         debug(", size:  0x%x %s\n",
 723                               FAT2CPU32(dentptr->size),
 724                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 725
 726                         return retdent;
 727                 }
 728
 729                 curclust = get_fatent(mydata, curclust);
 730                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 731                         debug("curclust: 0x%x\n", curclust);
 732                         printf("Invalid FAT entry\n");
 733                         return NULL;
 734                 }
 735         }
 736
 737         return NULL;
 738 }
 739
 740 /*
 741  * Read boot sector and volume info from a FAT filesystem
 742  */
 743 static int
 744 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 745 {
 746         __u8 *block;
 747         volume_info *vistart;
 748         int ret = 0;
 749
 750         if (cur_dev == NULL) {
 751                 debug("Error: no device selected\n");
 752                 return -1;
 753         }
 754
 755         block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
 756         if (block == NULL) {
 757                 debug("Error: allocating block\n");
 758                 return -1;
 759         }
 760
 761         if (disk_read(0, 1, block) < 0) {
 762                 debug("Error: reading block\n");
 763                 goto fail;
 764         }
 765
 766         memcpy(bs, block, sizeof(boot_sector));
 767         bs->reserved = FAT2CPU16(bs->reserved);
 768         bs->fat_length = FAT2CPU16(bs->fat_length);
 769         bs->secs_track = FAT2CPU16(bs->secs_track);
 770         bs->heads = FAT2CPU16(bs->heads);
 771         bs->total_sect = FAT2CPU32(bs->total_sect);
 772
 773         /* FAT32 entries */
 774         if (bs->fat_length == 0) {
 775                 /* Assume FAT32 */
 776                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 777                 bs->flags = FAT2CPU16(bs->flags);
 778                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 779                 bs->info_sector = FAT2CPU16(bs->info_sector);
 780                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 781                 vistart = (volume_info *)(block + sizeof(boot_sector));
 782                 *fatsize = 32;
 783         } else {
 784                 vistart = (volume_info *)&(bs->fat32_length);
 785                 *fatsize = 0;
 786         }
 787         memcpy(volinfo, vistart, sizeof(volume_info));
 788
 789         if (*fatsize == 32) {
 790                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 791                         goto exit;
 792         } else {
 793                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 794                         *fatsize = 12;
 795                         goto exit;
 796                 }
 797                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 798                         *fatsize = 16;
 799                         goto exit;
 800                 }
 801         }
 802
 803         debug("Error: broken fs_type sign\n");
 804 fail:
 805         ret = -1;
 806 exit:
 807         free(block);
 808         return ret;
 809 }
 810
 811 __u8 do_fat_read_at_block[MAX_CLUSTSIZE]
 812         __aligned(ARCH_DMA_MINALIGN);
 813
 814 int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
 815                    loff_t maxsize, int dols, int dogetsize, loff_t *size)
 816 {
 817         char fnamecopy[2048];
 818         boot_sector bs;
 819         volume_info volinfo;
 820         fsdata datablock;
 821         fsdata *mydata = &datablock;
 822         dir_entry *dentptr = NULL;
 823         __u16 prevcksum = 0xffff;
 824         char *subname = "";
 825         __u32 cursect;
 826         int idx, isdir = 0;
 827         int files = 0, dirs = 0;
 828         int ret = -1;
 829         int firsttime;
 830         __u32 root_cluster = 0;
 831         __u32 read_blk;
 832         int rootdir_size = 0;
 833         int buffer_blk_cnt;
 834         int do_read;
 835         __u8 *dir_ptr;
 836
 837         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 838                 debug("Error: reading boot sector\n");
 839                 return -1;
 840         }
 841
 842         if (mydata->fatsize == 32) {
 843                 root_cluster = bs.root_cluster;
 844                 mydata->fatlength = bs.fat32_length;
 845         } else {
 846                 mydata->fatlength = bs.fat_length;
 847         }
 848
 849         mydata->fat_sect = bs.reserved;
 850
 851         cursect = mydata->rootdir_sect
 852                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 853
 854         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 855         mydata->clust_size = bs.cluster_size;
 856         if (mydata->sect_size != cur_part_info.blksz) {
 857                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 858                                 mydata->sect_size, cur_part_info.blksz);
 859                 return -1;
 860         }
 861
 862         if (mydata->fatsize == 32) {
 863                 mydata->data_begin = mydata->rootdir_sect -
 864                                         (mydata->clust_size * 2);
 865         } else {
 866                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 867                                  bs.dir_entries[0]) *
 868                                  sizeof(dir_entry)) /
 869                                  mydata->sect_size;
 870                 mydata->data_begin = mydata->rootdir_sect +
 871                                         rootdir_size -
 872                                         (mydata->clust_size * 2);
 873         }
 874
 875         mydata->fatbufnum = -1;
 876         mydata->fat_dirty = 0;
 877         mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
 878         if (mydata->fatbuf == NULL) {
 879                 debug("Error: allocating memory\n");
 880                 return -1;
 881         }
 882
 883         if (vfat_enabled)
 884                 debug("VFAT Support enabled\n");
 885
 886         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 887                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 888         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 889                "Data begins at: %d\n",
 890                root_cluster,
 891                mydata->rootdir_sect,
 892                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 893         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 894               mydata->clust_size);
 895
 896         /* "cwd" is always the root... */
 897         while (ISDIRDELIM(*filename))
 898                 filename++;
 899
 900         /* Make a copy of the filename and convert it to lowercase */
 901         strcpy(fnamecopy, filename);
 902         downcase(fnamecopy);
 903
 904 root_reparse:
 905         if (*fnamecopy == '\0') {
 906                 if (!dols)
 907                         goto exit;
 908
 909                 dols = LS_ROOT;
 910         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 911                 isdir = 1;
 912                 fnamecopy[idx] = '\0';
 913                 subname = fnamecopy + idx + 1;
 914
 915                 /* Handle multiple delimiters */
 916                 while (ISDIRDELIM(*subname))
 917                         subname++;
 918         } else if (dols) {
 919                 isdir = 1;
 920         }
 921
 922         buffer_blk_cnt = 0;
 923         firsttime = 1;
 924         while (1) {
 925                 int i;
 926
 927                 if (mydata->fatsize == 32 || firsttime) {
 928                         dir_ptr = do_fat_read_at_block;
 929                         firsttime = 0;
 930                 } else {
 931                         /**
 932                          * FAT16 sector buffer modification:
 933                          * Each loop, the second buffered block is moved to
 934                          * the buffer begin, and two next sectors are read
 935                          * next to the previously moved one. So the sector
 936                          * buffer keeps always 3 sectors for fat16.
 937                          * And the current sector is the buffer second sector
 938                          * beside the "firsttime" read, when it is the first one.
 939                          *
 940                          * PREFETCH_BLOCKS is 2 for FAT16 == loop[0:1]
 941                          * n = computed root dir sector
 942                          * loop |  cursect-1  | cursect    | cursect+1  |
 943                          *   0  |  sector n+0 | sector n+1 | none       |
 944                          *   1  |  none       | sector n+0 | sector n+1 |
 945                          *   0  |  sector n+1 | sector n+2 | sector n+3 |
 946                          *   1  |  sector n+3 | ...
 947                         */
 948                         dir_ptr = (do_fat_read_at_block + mydata->sect_size);
 949                         memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
 950                 }
 951
 952                 do_read = 1;
 953
 954                 if (mydata->fatsize == 32 && buffer_blk_cnt)
 955                         do_read = 0;
 956
 957                 if (do_read) {
 958                         read_blk = (mydata->fatsize == 32) ?
 959                                     mydata->clust_size : PREFETCH_BLOCKS;
 960
 961                         debug("FAT read(sect=%d, cnt:%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 962                                 cursect, read_blk, mydata->clust_size, DIRENTSPERBLOCK);
 963
 964                         if (disk_read(cursect, read_blk, dir_ptr) < 0) {
 965                                 debug("Error: reading rootdir block\n");
 966                                 goto exit;
 967                         }
 968
 969                         dentptr = (dir_entry *)dir_ptr;
 970                 }
 971
 972                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 973                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 974                         __u8 csum;
 975
 976                         l_name[0] = '\0';
 977                         if (dentptr->name[0] == DELETED_FLAG) {
 978                                 dentptr++;
 979                                 continue;
 980                         }
 981
 982                         if (vfat_enabled)
 983                                 csum = mkcksum(dentptr->name, dentptr->ext);
 984
 985                         if (dentptr->attr & ATTR_VOLUME) {
 986                                 if (vfat_enabled &&
 987                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 988                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 989                                         prevcksum =
 990                                                 ((dir_slot *)dentptr)->alias_checksum;
 991
 992                                         get_vfatname(mydata,
 993                                                      root_cluster,
 994                                                      dir_ptr,
 995                                                      dentptr, l_name);
 996
 997                                         if (dols == LS_ROOT) {
 998                                                 char dirc;
 999                                                 int doit = 0;
1000                                                 int isdir =
1001                                                         (dentptr->attr & ATTR_DIR);
1002
1003                                                 if (isdir) {
1004                                                         dirs++;
1005                                                         dirc = '/';
1006                                                         doit = 1;
1007                                                 } else {
1008                                                         dirc = ' ';
1009                                                         if (l_name[0] != 0) {
1010                                                                 files++;
1011                                                                 doit = 1;
1012                                                         }
1013                                                 }
1014                                                 if (doit) {
1015                                                         if (dirc == ' ') {
1016                                                                 printf(" %8u   %s%c\n",
1017                                                                        FAT2CPU32(dentptr->size),
1018                                                                         l_name,
1019                                                                         dirc);
1020                                                         } else {
1021                                                                 printf("            %s%c\n",
1022                                                                         l_name,
1023                                                                         dirc);
1024                                                         }
1025                                                 }
1026                                                 dentptr++;
1027                                                 continue;
1028                                         }
1029                                         debug("Rootvfatname: |%s|\n",
1030                                                l_name);
1031                                 } else {
1032                                         /* Volume label or VFAT entry */
1033                                         dentptr++;
1034                                         continue;
1035                                 }
1036                         } else if (dentptr->name[0] == 0) {
1037                                 debug("RootDentname == NULL - %d\n", i);
1038                                 if (dols == LS_ROOT) {
1039                                         printf("\n%d file(s), %d dir(s)\n\n",
1040                                                 files, dirs);
1041                                         ret = 0;
1042                                 }
1043                                 goto exit;
1044                         }
1045                         else if (vfat_enabled &&
1046                                  dols == LS_ROOT && csum == prevcksum) {
1047                                 prevcksum = 0xffff;
1048                                 dentptr++;
1049                                 continue;
1050                         }
1051
1052                         get_name(dentptr, s_name);
1053
1054                         if (dols == LS_ROOT) {
1055                                 int isdir = (dentptr->attr & ATTR_DIR);
1056                                 char dirc;
1057                                 int doit = 0;
1058
1059                                 if (isdir) {
1060                                         dirc = '/';
1061                                         if (s_name[0] != 0) {
1062                                                 dirs++;
1063                                                 doit = 1;
1064                                         }
1065                                 } else {
1066                                         dirc = ' ';
1067                                         if (s_name[0] != 0) {
1068                                                 files++;
1069                                                 doit = 1;
1070                                         }
1071                                 }
1072                                 if (doit) {
1073                                         if (dirc == ' ') {
1074                                                 printf(" %8u   %s%c\n",
1075                                                        FAT2CPU32(dentptr->size),
1076                                                         s_name, dirc);
1077                                         } else {
1078                                                 printf("            %s%c\n",
1079                                                         s_name, dirc);
1080                                         }
1081                                 }
1082                                 dentptr++;
1083                                 continue;
1084                         }
1085
1086                         if (strcmp(fnamecopy, s_name)
1087                             && strcmp(fnamecopy, l_name)) {
1088                                 debug("RootMismatch: |%s|%s|\n", s_name,
1089                                        l_name);
1090                                 dentptr++;
1091                                 continue;
1092                         }
1093
1094                         if (isdir && !(dentptr->attr & ATTR_DIR))
1095                                 goto exit;
1096
1097                         debug("RootName: %s", s_name);
1098                         debug(", start: 0x%x", START(dentptr));
1099                         debug(", size:  0x%x %s\n",
1100                                FAT2CPU32(dentptr->size),
1101                                isdir ? "(DIR)" : "");
1102
1103                         goto rootdir_done;      /* We got a match */
1104                 }
1105                 debug("END LOOP: buffer_blk_cnt=%d   clust_size=%d\n", buffer_blk_cnt,
1106                        mydata->clust_size);
1107
1108                 /*
1109                  * On FAT32 we must fetch the FAT entries for the next
1110                  * root directory clusters when a cluster has been
1111                  * completely processed.
1112                  */
1113                 ++buffer_blk_cnt;
1114                 int rootdir_end = 0;
1115                 if (mydata->fatsize == 32) {
1116                         if (buffer_blk_cnt == mydata->clust_size) {
1117                                 int nxtsect = 0;
1118                                 int nxt_clust = 0;
1119
1120                                 nxt_clust = get_fatent(mydata, root_cluster);
1121                                 rootdir_end = CHECK_CLUST(nxt_clust, 32);
1122
1123                                 nxtsect = mydata->data_begin +
1124                                         (nxt_clust * mydata->clust_size);
1125
1126                                 root_cluster = nxt_clust;
1127
1128                                 cursect = nxtsect;
1129                                 buffer_blk_cnt = 0;
1130                         }
1131                 } else {
1132                         if (buffer_blk_cnt == PREFETCH_BLOCKS)
1133                                 buffer_blk_cnt = 0;
1134
1135                         rootdir_end = (++cursect - mydata->rootdir_sect >=
1136                                        rootdir_size);
1137                 }
1138
1139                 /* If end of rootdir reached */
1140                 if (rootdir_end) {
1141                         if (dols == LS_ROOT) {
1142                                 printf("\n%d file(s), %d dir(s)\n\n",
1143                                        files, dirs);
1144                                 *size = 0;
1145                         }
1146                         goto exit;
1147                 }
1148         }
1149 rootdir_done:
1150
1151         firsttime = 1;
1152
1153         while (isdir) {
1154                 int startsect = mydata->data_begin
1155                         + START(dentptr) * mydata->clust_size;
1156                 dir_entry dent;
1157                 char *nextname = NULL;
1158
1159                 dent = *dentptr;
1160                 dentptr = &dent;
1161
1162                 idx = dirdelim(subname);
1163
1164                 if (idx >= 0) {
1165                         subname[idx] = '\0';
1166                         nextname = subname + idx + 1;
1167                         /* Handle multiple delimiters */
1168                         while (ISDIRDELIM(*nextname))
1169                                 nextname++;
1170                         if (dols && *nextname == '\0')
1171                                 firsttime = 0;
1172                 } else {
1173                         if (dols && firsttime) {
1174                                 firsttime = 0;
1175                         } else {
1176                                 isdir = 0;
1177                         }
1178                 }
1179
1180                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1181                                      isdir ? 0 : dols) == NULL) {
1182                         if (dols && !isdir)
1183                                 *size = 0;
1184                         goto exit;
1185                 }
1186
1187                 if (isdir && !(dentptr->attr & ATTR_DIR))
1188                         goto exit;
1189
1190                 /*
1191                  * If we are looking for a directory, and found a directory
1192                  * type entry, and the entry is for the root directory (as
1193                  * denoted by a cluster number of 0), jump back to the start
1194                  * of the function, since at least on FAT12/16, the root dir
1195                  * lives in a hard-coded location and needs special handling
1196                  * to parse, rather than simply following the cluster linked
1197                  * list in the FAT, like other directories.
1198                  */
1199                 if (isdir && (dentptr->attr & ATTR_DIR) && !START(dentptr)) {
1200                         /*
1201                          * Modify the filename to remove the prefix that gets
1202                          * back to the root directory, so the initial root dir
1203                          * parsing code can continue from where we are without
1204                          * confusion.
1205                          */
1206                         strcpy(fnamecopy, nextname ?: "");
1207                         /*
1208                          * Set up state the same way as the function does when
1209                          * first started. This is required for the root dir
1210                          * parsing code operates in its expected environment.
1211                          */
1212                         subname = "";
1213                         cursect = mydata->rootdir_sect;
1214                         isdir = 0;
1215                         goto root_reparse;
1216                 }
1217
1218                 if (idx >= 0)
1219                         subname = nextname;
1220         }
1221
1222         if (dogetsize) {
1223                 *size = FAT2CPU32(dentptr->size);
1224                 ret = 0;
1225         } else {
1226                 ret = get_contents(mydata, dentptr, pos, buffer, maxsize, size);
1227         }
1228         debug("Size: %u, got: %llu\n", FAT2CPU32(dentptr->size), *size);
1229
1230 exit:
1231         free(mydata->fatbuf);
1232         return ret;
1233 }
1234
1235 int do_fat_read(const char *filename, void *buffer, loff_t maxsize, int dols,
1236                 loff_t *actread)
1237 {
1238         return do_fat_read_at(filename, 0, buffer, maxsize, dols, 0, actread);
1239 }
1240
1241 int file_fat_detectfs(void)
1242 {
1243         boot_sector bs;
1244         volume_info volinfo;
1245         int fatsize;
1246         char vol_label[12];
1247
1248         if (cur_dev == NULL) {
1249                 printf("No current device\n");
1250                 return 1;
1251         }
1252
1253 #if defined(CONFIG_IDE) || \
1254     defined(CONFIG_SATA) || \
1255     defined(CONFIG_SCSI) || \
1256     defined(CONFIG_CMD_USB) || \
1257     defined(CONFIG_MMC)
1258         printf("Interface:  ");
1259         switch (cur_dev->if_type) {
1260         case IF_TYPE_IDE:
1261                 printf("IDE");
1262                 break;
1263         case IF_TYPE_SATA:
1264                 printf("SATA");
1265                 break;
1266         case IF_TYPE_SCSI:
1267                 printf("SCSI");
1268                 break;
1269         case IF_TYPE_ATAPI:
1270                 printf("ATAPI");
1271                 break;
1272         case IF_TYPE_USB:
1273                 printf("USB");
1274                 break;
1275         case IF_TYPE_DOC:
1276                 printf("DOC");
1277                 break;
1278         case IF_TYPE_MMC:
1279                 printf("MMC");
1280                 break;
1281         default:
1282                 printf("Unknown");
1283         }
1284
1285         printf("\n  Device %d: ", cur_dev->devnum);
1286         dev_print(cur_dev);
1287 #endif
1288
1289         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1290                 printf("\nNo valid FAT fs found\n");
1291                 return 1;
1292         }
1293
1294         memcpy(vol_label, volinfo.volume_label, 11);
1295         vol_label[11] = '\0';
1296         volinfo.fs_type[5] = '\0';
1297
1298         printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
1299
1300         return 0;
1301 }
1302
1303 int file_fat_ls(const char *dir)
1304 {
1305         loff_t size;
1306
1307         return do_fat_read(dir, NULL, 0, LS_YES, &size);
1308 }
1309
1310 int fat_exists(const char *filename)
1311 {
1312         int ret;
1313         loff_t size;
1314
1315         ret = do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, &size);
1316         return ret == 0;
1317 }
1318
1319 int fat_size(const char *filename, loff_t *size)
1320 {
1321         return do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, size);
1322 }
1323
1324 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
1325                      loff_t maxsize, loff_t *actread)
1326 {
1327         printf("reading %s\n", filename);
1328         return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO, 0,
1329                               actread);
1330 }
1331
1332 int file_fat_read(const char *filename, void *buffer, int maxsize)
1333 {
1334         loff_t actread;
1335         int ret;
1336
1337         ret =  file_fat_read_at(filename, 0, buffer, maxsize, &actread);
1338         if (ret)
1339                 return ret;
1340         else
1341                 return actread;
1342 }
1343
1344 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
1345                   loff_t *actread)
1346 {
1347         int ret;
1348
1349         ret = file_fat_read_at(filename, offset, buf, len, actread);
1350         if (ret)
1351                 printf("** Unable to read file %s **\n", filename);
1352
1353         return ret;
1354 }
1355
1356 void fat_close(void)
1357 {
1358 }