git.sur5r.net Git - u-boot/blob - 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 #ifdef CONFIG_PARTITION_UUIDS
 114                 info.uuid[0] = 0;
 115 #endif
 116         }
 117
 118         return fat_set_blk_dev(dev_desc, &info);
 119 }
 120
 121 /*
 122  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 123  * Return index into string if found, -1 otherwise.
 124  */
 125 static int dirdelim(char *str)
 126 {
 127         char *start = str;
 128
 129         while (*str != '\0') {
 130                 if (ISDIRDELIM(*str))
 131                         return str - start;
 132                 str++;
 133         }
 134         return -1;
 135 }
 136
 137 /*
 138  * Extract zero terminated short name from a directory entry.
 139  */
 140 static void get_name(dir_entry *dirent, char *s_name)
 141 {
 142         char *ptr;
 143
 144         memcpy(s_name, dirent->name, 8);
 145         s_name[8] = '\0';
 146         ptr = s_name;
 147         while (*ptr && *ptr != ' ')
 148                 ptr++;
 149         if (dirent->ext[0] && dirent->ext[0] != ' ') {
 150                 *ptr = '.';
 151                 ptr++;
 152                 memcpy(ptr, dirent->ext, 3);
 153                 ptr[3] = '\0';
 154                 while (*ptr && *ptr != ' ')
 155                         ptr++;
 156         }
 157         *ptr = '\0';
 158         if (*s_name == DELETED_FLAG)
 159                 *s_name = '\0';
 160         else if (*s_name == aRING)
 161                 *s_name = DELETED_FLAG;
 162         downcase(s_name);
 163 }
 164
 165 /*
 166  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 167  * On failure 0x00 is returned.
 168  */
 169 static __u32 get_fatent(fsdata *mydata, __u32 entry)
 170 {
 171         __u32 bufnum;
 172         __u32 off16, offset;
 173         __u32 ret = 0x00;
 174         __u16 val1, val2;
 175
 176         switch (mydata->fatsize) {
 177         case 32:
 178                 bufnum = entry / FAT32BUFSIZE;
 179                 offset = entry - bufnum * FAT32BUFSIZE;
 180                 break;
 181         case 16:
 182                 bufnum = entry / FAT16BUFSIZE;
 183                 offset = entry - bufnum * FAT16BUFSIZE;
 184                 break;
 185         case 12:
 186                 bufnum = entry / FAT12BUFSIZE;
 187                 offset = entry - bufnum * FAT12BUFSIZE;
 188                 break;
 189
 190         default:
 191                 /* Unsupported FAT size */
 192                 return ret;
 193         }
 194
 195         debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
 196                mydata->fatsize, entry, entry, offset, offset);
 197
 198         /* Read a new block of FAT entries into the cache. */
 199         if (bufnum != mydata->fatbufnum) {
 200                 __u32 getsize = FATBUFBLOCKS;
 201                 __u8 *bufptr = mydata->fatbuf;
 202                 __u32 fatlength = mydata->fatlength;
 203                 __u32 startblock = bufnum * FATBUFBLOCKS;
 204
 205                 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
 206                 if (startblock + getsize > fatlength)
 207                         getsize = fatlength - startblock;
 208
 209                 startblock += mydata->fat_sect; /* Offset from start of disk */
 210
 211                 if (disk_read(startblock, getsize, bufptr) < 0) {
 212                         debug("Error reading FAT blocks\n");
 213                         return ret;
 214                 }
 215                 mydata->fatbufnum = bufnum;
 216         }
 217
 218         /* Get the actual entry from the table */
 219         switch (mydata->fatsize) {
 220         case 32:
 221                 ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
 222                 break;
 223         case 16:
 224                 ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
 225                 break;
 226         case 12:
 227                 off16 = (offset * 3) / 4;
 228
 229                 switch (offset & 0x3) {
 230                 case 0:
 231                         ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
 232                         ret &= 0xfff;
 233                         break;
 234                 case 1:
 235                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 236                         val1 &= 0xf000;
 237                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 238                         val2 &= 0x00ff;
 239                         ret = (val2 << 4) | (val1 >> 12);
 240                         break;
 241                 case 2:
 242                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 243                         val1 &= 0xff00;
 244                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 245                         val2 &= 0x000f;
 246                         ret = (val2 << 8) | (val1 >> 8);
 247                         break;
 248                 case 3:
 249                         ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 250                         ret = (ret & 0xfff0) >> 4;
 251                         break;
 252                 default:
 253                         break;
 254                 }
 255                 break;
 256         }
 257         debug("FAT%d: ret: %08x, offset: %04x\n",
 258                mydata->fatsize, ret, offset);
 259
 260         return ret;
 261 }
 262
 263 /*
 264  * Read at most 'size' bytes from the specified cluster into 'buffer'.
 265  * Return 0 on success, -1 otherwise.
 266  */
 267 static int
 268 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
 269 {
 270         __u32 idx = 0;
 271         __u32 startsect;
 272         int ret;
 273
 274         if (clustnum > 0) {
 275                 startsect = mydata->data_begin +
 276                                 clustnum * mydata->clust_size;
 277         } else {
 278                 startsect = mydata->rootdir_sect;
 279         }
 280
 281         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 282
 283         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 284                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 285
 286                 printf("FAT: Misaligned buffer address (%p)\n", buffer);
 287
 288                 while (size >= mydata->sect_size) {
 289                         ret = disk_read(startsect++, 1, tmpbuf);
 290                         if (ret != 1) {
 291                                 debug("Error reading data (got %d)\n", ret);
 292                                 return -1;
 293                         }
 294
 295                         memcpy(buffer, tmpbuf, mydata->sect_size);
 296                         buffer += mydata->sect_size;
 297                         size -= mydata->sect_size;
 298                 }
 299         } else {
 300                 idx = size / mydata->sect_size;
 301                 ret = disk_read(startsect, idx, buffer);
 302                 if (ret != idx) {
 303                         debug("Error reading data (got %d)\n", ret);
 304                         return -1;
 305                 }
 306                 startsect += idx;
 307                 idx *= mydata->sect_size;
 308                 buffer += idx;
 309                 size -= idx;
 310         }
 311         if (size) {
 312                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 313
 314                 ret = disk_read(startsect, 1, tmpbuf);
 315                 if (ret != 1) {
 316                         debug("Error reading data (got %d)\n", ret);
 317                         return -1;
 318                 }
 319
 320                 memcpy(buffer, tmpbuf, size);
 321         }
 322
 323         return 0;
 324 }
 325
 326 /*
 327  * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
 328  * into 'buffer'.
 329  * Update the number of bytes read in *gotsize or return -1 on fatal errors.
 330  */
 331 __u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
 332         __aligned(ARCH_DMA_MINALIGN);
 333
 334 static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
 335                         __u8 *buffer, loff_t maxsize, loff_t *gotsize)
 336 {
 337         loff_t filesize = FAT2CPU32(dentptr->size);
 338         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 339         __u32 curclust = START(dentptr);
 340         __u32 endclust, newclust;
 341         loff_t actsize;
 342
 343         *gotsize = 0;
 344         debug("Filesize: %llu bytes\n", filesize);
 345
 346         if (pos >= filesize) {
 347                 debug("Read position past EOF: %llu\n", pos);
 348                 return 0;
 349         }
 350
 351         if (maxsize > 0 && filesize > pos + maxsize)
 352                 filesize = pos + maxsize;
 353
 354         debug("%llu bytes\n", filesize);
 355
 356         actsize = bytesperclust;
 357
 358         /* go to cluster at pos */
 359         while (actsize <= pos) {
 360                 curclust = get_fatent(mydata, curclust);
 361                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 362                         debug("curclust: 0x%x\n", curclust);
 363                         debug("Invalid FAT entry\n");
 364                         return 0;
 365                 }
 366                 actsize += bytesperclust;
 367         }
 368
 369         /* actsize > pos */
 370         actsize -= bytesperclust;
 371         filesize -= actsize;
 372         pos -= actsize;
 373
 374         /* align to beginning of next cluster if any */
 375         if (pos) {
 376                 actsize = min(filesize, (loff_t)bytesperclust);
 377                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 378                                 (int)actsize) != 0) {
 379                         printf("Error reading cluster\n");
 380                         return -1;
 381                 }
 382                 filesize -= actsize;
 383                 actsize -= pos;
 384                 memcpy(buffer, get_contents_vfatname_block + pos, actsize);
 385                 *gotsize += actsize;
 386                 if (!filesize)
 387                         return 0;
 388                 buffer += actsize;
 389
 390                 curclust = get_fatent(mydata, curclust);
 391                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 392                         debug("curclust: 0x%x\n", curclust);
 393                         debug("Invalid FAT entry\n");
 394                         return 0;
 395                 }
 396         }
 397
 398         actsize = bytesperclust;
 399         endclust = curclust;
 400
 401         do {
 402                 /* search for consecutive clusters */
 403                 while (actsize < filesize) {
 404                         newclust = get_fatent(mydata, endclust);
 405                         if ((newclust - 1) != endclust)
 406                                 goto getit;
 407                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 408                                 debug("curclust: 0x%x\n", newclust);
 409                                 debug("Invalid FAT entry\n");
 410                                 return 0;
 411                         }
 412                         endclust = newclust;
 413                         actsize += bytesperclust;
 414                 }
 415
 416                 /* get remaining bytes */
 417                 actsize = filesize;
 418                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 419                         printf("Error reading cluster\n");
 420                         return -1;
 421                 }
 422                 *gotsize += actsize;
 423                 return 0;
 424 getit:
 425                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 426                         printf("Error reading cluster\n");
 427                         return -1;
 428                 }
 429                 *gotsize += (int)actsize;
 430                 filesize -= actsize;
 431                 buffer += actsize;
 432
 433                 curclust = get_fatent(mydata, endclust);
 434                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 435                         debug("curclust: 0x%x\n", curclust);
 436                         printf("Invalid FAT entry\n");
 437                         return 0;
 438                 }
 439                 actsize = bytesperclust;
 440                 endclust = curclust;
 441         } while (1);
 442 }
 443
 444 /*
 445  * Extract the file name information from 'slotptr' into 'l_name',
 446  * starting at l_name[*idx].
 447  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 448  */
 449 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
 450 {
 451         int j;
 452
 453         for (j = 0; j <= 8; j += 2) {
 454                 l_name[*idx] = slotptr->name0_4[j];
 455                 if (l_name[*idx] == 0x00)
 456                         return 1;
 457                 (*idx)++;
 458         }
 459         for (j = 0; j <= 10; j += 2) {
 460                 l_name[*idx] = slotptr->name5_10[j];
 461                 if (l_name[*idx] == 0x00)
 462                         return 1;
 463                 (*idx)++;
 464         }
 465         for (j = 0; j <= 2; j += 2) {
 466                 l_name[*idx] = slotptr->name11_12[j];
 467                 if (l_name[*idx] == 0x00)
 468                         return 1;
 469                 (*idx)++;
 470         }
 471
 472         return 0;
 473 }
 474
 475 /*
 476  * Extract the full long filename starting at 'retdent' (which is really
 477  * a slot) into 'l_name'. If successful also copy the real directory entry
 478  * into 'retdent'
 479  * Return 0 on success, -1 otherwise.
 480  */
 481 static int
 482 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 483              dir_entry *retdent, char *l_name)
 484 {
 485         dir_entry *realdent;
 486         dir_slot *slotptr = (dir_slot *)retdent;
 487         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 488                                                         PREFETCH_BLOCKS :
 489                                                         mydata->clust_size);
 490         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 491         int idx = 0;
 492
 493         if (counter > VFAT_MAXSEQ) {
 494                 debug("Error: VFAT name is too long\n");
 495                 return -1;
 496         }
 497
 498         while ((__u8 *)slotptr < buflimit) {
 499                 if (counter == 0)
 500                         break;
 501                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 502                         return -1;
 503                 slotptr++;
 504                 counter--;
 505         }
 506
 507         if ((__u8 *)slotptr >= buflimit) {
 508                 dir_slot *slotptr2;
 509
 510                 if (curclust == 0)
 511                         return -1;
 512                 curclust = get_fatent(mydata, curclust);
 513                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 514                         debug("curclust: 0x%x\n", curclust);
 515                         printf("Invalid FAT entry\n");
 516                         return -1;
 517                 }
 518
 519                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 520                                 mydata->clust_size * mydata->sect_size) != 0) {
 521                         debug("Error: reading directory block\n");
 522                         return -1;
 523                 }
 524
 525                 slotptr2 = (dir_slot *)get_contents_vfatname_block;
 526                 while (counter > 0) {
 527                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 528                             & 0xff) != counter)
 529                                 return -1;
 530                         slotptr2++;
 531                         counter--;
 532                 }
 533
 534                 /* Save the real directory entry */
 535                 realdent = (dir_entry *)slotptr2;
 536                 while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
 537                         slotptr2--;
 538                         slot2str(slotptr2, l_name, &idx);
 539                 }
 540         } else {
 541                 /* Save the real directory entry */
 542                 realdent = (dir_entry *)slotptr;
 543         }
 544
 545         do {
 546                 slotptr--;
 547                 if (slot2str(slotptr, l_name, &idx))
 548                         break;
 549         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 550
 551         l_name[idx] = '\0';
 552         if (*l_name == DELETED_FLAG)
 553                 *l_name = '\0';
 554         else if (*l_name == aRING)
 555                 *l_name = DELETED_FLAG;
 556         downcase(l_name);
 557
 558         /* Return the real directory entry */
 559         memcpy(retdent, realdent, sizeof(dir_entry));
 560
 561         return 0;
 562 }
 563
 564 /* Calculate short name checksum */
 565 static __u8 mkcksum(const char name[8], const char ext[3])
 566 {
 567         int i;
 568
 569         __u8 ret = 0;
 570
 571         for (i = 0; i < 8; i++)
 572                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
 573         for (i = 0; i < 3; i++)
 574                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
 575
 576         return ret;
 577 }
 578
 579 /*
 580  * Get the directory entry associated with 'filename' from the directory
 581  * starting at 'startsect'
 582  */
 583 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
 584         __aligned(ARCH_DMA_MINALIGN);
 585
 586 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
 587                                   char *filename, dir_entry *retdent,
 588                                   int dols)
 589 {
 590         __u16 prevcksum = 0xffff;
 591         __u32 curclust = START(retdent);
 592         int files = 0, dirs = 0;
 593
 594         debug("get_dentfromdir: %s\n", filename);
 595
 596         while (1) {
 597                 dir_entry *dentptr;
 598
 599                 int i;
 600
 601                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 602                                 mydata->clust_size * mydata->sect_size) != 0) {
 603                         debug("Error: reading directory block\n");
 604                         return NULL;
 605                 }
 606
 607                 dentptr = (dir_entry *)get_dentfromdir_block;
 608
 609                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 610                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 611
 612                         l_name[0] = '\0';
 613                         if (dentptr->name[0] == DELETED_FLAG) {
 614                                 dentptr++;
 615                                 continue;
 616                         }
 617                         if ((dentptr->attr & ATTR_VOLUME)) {
 618                                 if (vfat_enabled &&
 619                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 620                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 621                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 622                                         get_vfatname(mydata, curclust,
 623                                                      get_dentfromdir_block,
 624                                                      dentptr, l_name);
 625                                         if (dols) {
 626                                                 int isdir;
 627                                                 char dirc;
 628                                                 int doit = 0;
 629
 630                                                 isdir = (dentptr->attr & ATTR_DIR);
 631
 632                                                 if (isdir) {
 633                                                         dirs++;
 634                                                         dirc = '/';
 635                                                         doit = 1;
 636                                                 } else {
 637                                                         dirc = ' ';
 638                                                         if (l_name[0] != 0) {
 639                                                                 files++;
 640                                                                 doit = 1;
 641                                                         }
 642                                                 }
 643                                                 if (doit) {
 644                                                         if (dirc == ' ') {
 645                                                                 printf(" %8u   %s%c\n",
 646                                                                        FAT2CPU32(dentptr->size),
 647                                                                         l_name,
 648                                                                         dirc);
 649                                                         } else {
 650                                                                 printf("            %s%c\n",
 651                                                                         l_name,
 652                                                                         dirc);
 653                                                         }
 654                                                 }
 655                                                 dentptr++;
 656                                                 continue;
 657                                         }
 658                                         debug("vfatname: |%s|\n", l_name);
 659                                 } else {
 660                                         /* Volume label or VFAT entry */
 661                                         dentptr++;
 662                                         continue;
 663                                 }
 664                         }
 665                         if (dentptr->name[0] == 0) {
 666                                 if (dols) {
 667                                         printf("\n%d file(s), %d dir(s)\n\n",
 668                                                 files, dirs);
 669                                 }
 670                                 debug("Dentname == NULL - %d\n", i);
 671                                 return NULL;
 672                         }
 673                         if (vfat_enabled) {
 674                                 __u8 csum = mkcksum(dentptr->name, dentptr->ext);
 675                                 if (dols && csum == prevcksum) {
 676                                         prevcksum = 0xffff;
 677                                         dentptr++;
 678                                         continue;
 679                                 }
 680                         }
 681
 682                         get_name(dentptr, s_name);
 683                         if (dols) {
 684                                 int isdir = (dentptr->attr & ATTR_DIR);
 685                                 char dirc;
 686                                 int doit = 0;
 687
 688                                 if (isdir) {
 689                                         dirs++;
 690                                         dirc = '/';
 691                                         doit = 1;
 692                                 } else {
 693                                         dirc = ' ';
 694                                         if (s_name[0] != 0) {
 695                                                 files++;
 696                                                 doit = 1;
 697                                         }
 698                                 }
 699
 700                                 if (doit) {
 701                                         if (dirc == ' ') {
 702                                                 printf(" %8u   %s%c\n",
 703                                                        FAT2CPU32(dentptr->size),
 704                                                         s_name, dirc);
 705                                         } else {
 706                                                 printf("            %s%c\n",
 707                                                         s_name, dirc);
 708                                         }
 709                                 }
 710
 711                                 dentptr++;
 712                                 continue;
 713                         }
 714
 715                         if (strcmp(filename, s_name)
 716                             && strcmp(filename, l_name)) {
 717                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 718                                 dentptr++;
 719                                 continue;
 720                         }
 721
 722                         memcpy(retdent, dentptr, sizeof(dir_entry));
 723
 724                         debug("DentName: %s", s_name);
 725                         debug(", start: 0x%x", START(dentptr));
 726                         debug(", size:  0x%x %s\n",
 727                               FAT2CPU32(dentptr->size),
 728                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 729
 730                         return retdent;
 731                 }
 732
 733                 curclust = get_fatent(mydata, curclust);
 734                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 735                         debug("curclust: 0x%x\n", curclust);
 736                         printf("Invalid FAT entry\n");
 737                         return NULL;
 738                 }
 739         }
 740
 741         return NULL;
 742 }
 743
 744 /*
 745  * Read boot sector and volume info from a FAT filesystem
 746  */
 747 static int
 748 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 749 {
 750         __u8 *block;
 751         volume_info *vistart;
 752         int ret = 0;
 753
 754         if (cur_dev == NULL) {
 755                 debug("Error: no device selected\n");
 756                 return -1;
 757         }
 758
 759         block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
 760         if (block == NULL) {
 761                 debug("Error: allocating block\n");
 762                 return -1;
 763         }
 764
 765         if (disk_read(0, 1, block) < 0) {
 766                 debug("Error: reading block\n");
 767                 goto fail;
 768         }
 769
 770         memcpy(bs, block, sizeof(boot_sector));
 771         bs->reserved = FAT2CPU16(bs->reserved);
 772         bs->fat_length = FAT2CPU16(bs->fat_length);
 773         bs->secs_track = FAT2CPU16(bs->secs_track);
 774         bs->heads = FAT2CPU16(bs->heads);
 775         bs->total_sect = FAT2CPU32(bs->total_sect);
 776
 777         /* FAT32 entries */
 778         if (bs->fat_length == 0) {
 779                 /* Assume FAT32 */
 780                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 781                 bs->flags = FAT2CPU16(bs->flags);
 782                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 783                 bs->info_sector = FAT2CPU16(bs->info_sector);
 784                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 785                 vistart = (volume_info *)(block + sizeof(boot_sector));
 786                 *fatsize = 32;
 787         } else {
 788                 vistart = (volume_info *)&(bs->fat32_length);
 789                 *fatsize = 0;
 790         }
 791         memcpy(volinfo, vistart, sizeof(volume_info));
 792
 793         if (*fatsize == 32) {
 794                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 795                         goto exit;
 796         } else {
 797                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 798                         *fatsize = 12;
 799                         goto exit;
 800                 }
 801                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 802                         *fatsize = 16;
 803                         goto exit;
 804                 }
 805         }
 806
 807         debug("Error: broken fs_type sign\n");
 808 fail:
 809         ret = -1;
 810 exit:
 811         free(block);
 812         return ret;
 813 }
 814
 815 __u8 do_fat_read_at_block[MAX_CLUSTSIZE]
 816         __aligned(ARCH_DMA_MINALIGN);
 817
 818 int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
 819                    loff_t maxsize, int dols, int dogetsize, loff_t *size)
 820 {
 821         char fnamecopy[2048];
 822         boot_sector bs;
 823         volume_info volinfo;
 824         fsdata datablock;
 825         fsdata *mydata = &datablock;
 826         dir_entry *dentptr = NULL;
 827         __u16 prevcksum = 0xffff;
 828         char *subname = "";
 829         __u32 cursect;
 830         int idx, isdir = 0;
 831         int files = 0, dirs = 0;
 832         int ret = -1;
 833         int firsttime;
 834         __u32 root_cluster = 0;
 835         __u32 read_blk;
 836         int rootdir_size = 0;
 837         int buffer_blk_cnt;
 838         int do_read;
 839         __u8 *dir_ptr;
 840
 841         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 842                 debug("Error: reading boot sector\n");
 843                 return -1;
 844         }
 845
 846         if (mydata->fatsize == 32) {
 847                 root_cluster = bs.root_cluster;
 848                 mydata->fatlength = bs.fat32_length;
 849         } else {
 850                 mydata->fatlength = bs.fat_length;
 851         }
 852
 853         mydata->fat_sect = bs.reserved;
 854
 855         cursect = mydata->rootdir_sect
 856                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 857
 858         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 859         mydata->clust_size = bs.cluster_size;
 860         if (mydata->sect_size != cur_part_info.blksz) {
 861                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 862                                 mydata->sect_size, cur_part_info.blksz);
 863                 return -1;
 864         }
 865
 866         if (mydata->fatsize == 32) {
 867                 mydata->data_begin = mydata->rootdir_sect -
 868                                         (mydata->clust_size * 2);
 869         } else {
 870                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 871                                  bs.dir_entries[0]) *
 872                                  sizeof(dir_entry)) /
 873                                  mydata->sect_size;
 874                 mydata->data_begin = mydata->rootdir_sect +
 875                                         rootdir_size -
 876                                         (mydata->clust_size * 2);
 877         }
 878
 879         mydata->fatbufnum = -1;
 880         mydata->fat_dirty = 0;
 881         mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
 882         if (mydata->fatbuf == NULL) {
 883                 debug("Error: allocating memory\n");
 884                 return -1;
 885         }
 886
 887         if (vfat_enabled)
 888                 debug("VFAT Support enabled\n");
 889
 890         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 891                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 892         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 893                "Data begins at: %d\n",
 894                root_cluster,
 895                mydata->rootdir_sect,
 896                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 897         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 898               mydata->clust_size);
 899
 900         /* "cwd" is always the root... */
 901         while (ISDIRDELIM(*filename))
 902                 filename++;
 903
 904         /* Make a copy of the filename and convert it to lowercase */
 905         strcpy(fnamecopy, filename);
 906         downcase(fnamecopy);
 907
 908 root_reparse:
 909         if (*fnamecopy == '\0') {
 910                 if (!dols)
 911                         goto exit;
 912
 913                 dols = LS_ROOT;
 914         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 915                 isdir = 1;
 916                 fnamecopy[idx] = '\0';
 917                 subname = fnamecopy + idx + 1;
 918
 919                 /* Handle multiple delimiters */
 920                 while (ISDIRDELIM(*subname))
 921                         subname++;
 922         } else if (dols) {
 923                 isdir = 1;
 924         }
 925
 926         buffer_blk_cnt = 0;
 927         firsttime = 1;
 928         while (1) {
 929                 int i;
 930
 931                 if (mydata->fatsize == 32 || firsttime) {
 932                         dir_ptr = do_fat_read_at_block;
 933                         firsttime = 0;
 934                 } else {
 935                         /**
 936                          * FAT16 sector buffer modification:
 937                          * Each loop, the second buffered block is moved to
 938                          * the buffer begin, and two next sectors are read
 939                          * next to the previously moved one. So the sector
 940                          * buffer keeps always 3 sectors for fat16.
 941                          * And the current sector is the buffer second sector
 942                          * beside the "firsttime" read, when it is the first one.
 943                          *
 944                          * PREFETCH_BLOCKS is 2 for FAT16 == loop[0:1]
 945                          * n = computed root dir sector
 946                          * loop |  cursect-1  | cursect    | cursect+1  |
 947                          *   0  |  sector n+0 | sector n+1 | none       |
 948                          *   1  |  none       | sector n+0 | sector n+1 |
 949                          *   0  |  sector n+1 | sector n+2 | sector n+3 |
 950                          *   1  |  sector n+3 | ...
 951                         */
 952                         dir_ptr = (do_fat_read_at_block + mydata->sect_size);
 953                         memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
 954                 }
 955
 956                 do_read = 1;
 957
 958                 if (mydata->fatsize == 32 && buffer_blk_cnt)
 959                         do_read = 0;
 960
 961                 if (do_read) {
 962                         read_blk = (mydata->fatsize == 32) ?
 963                                     mydata->clust_size : PREFETCH_BLOCKS;
 964
 965                         debug("FAT read(sect=%d, cnt:%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 966                                 cursect, read_blk, mydata->clust_size, DIRENTSPERBLOCK);
 967
 968                         if (disk_read(cursect, read_blk, dir_ptr) < 0) {
 969                                 debug("Error: reading rootdir block\n");
 970                                 goto exit;
 971                         }
 972
 973                         dentptr = (dir_entry *)dir_ptr;
 974                 }
 975
 976                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 977                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 978                         __u8 csum;
 979
 980                         l_name[0] = '\0';
 981                         if (dentptr->name[0] == DELETED_FLAG) {
 982                                 dentptr++;
 983                                 continue;
 984                         }
 985
 986                         if (vfat_enabled)
 987                                 csum = mkcksum(dentptr->name, dentptr->ext);
 988
 989                         if (dentptr->attr & ATTR_VOLUME) {
 990                                 if (vfat_enabled &&
 991                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 992                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 993                                         prevcksum =
 994                                                 ((dir_slot *)dentptr)->alias_checksum;
 995
 996                                         get_vfatname(mydata,
 997                                                      root_cluster,
 998                                                      dir_ptr,
 999                                                      dentptr, l_name);
1000
1001                                         if (dols == LS_ROOT) {
1002                                                 char dirc;
1003                                                 int doit = 0;
1004                                                 int isdir =
1005                                                         (dentptr->attr & ATTR_DIR);
1006
1007                                                 if (isdir) {
1008                                                         dirs++;
1009                                                         dirc = '/';
1010                                                         doit = 1;
1011                                                 } else {
1012                                                         dirc = ' ';
1013                                                         if (l_name[0] != 0) {
1014                                                                 files++;
1015                                                                 doit = 1;
1016                                                         }
1017                                                 }
1018                                                 if (doit) {
1019                                                         if (dirc == ' ') {
1020                                                                 printf(" %8u   %s%c\n",
1021                                                                        FAT2CPU32(dentptr->size),
1022                                                                         l_name,
1023                                                                         dirc);
1024                                                         } else {
1025                                                                 printf("            %s%c\n",
1026                                                                         l_name,
1027                                                                         dirc);
1028                                                         }
1029                                                 }
1030                                                 dentptr++;
1031                                                 continue;
1032                                         }
1033                                         debug("Rootvfatname: |%s|\n",
1034                                                l_name);
1035                                 } else {
1036                                         /* Volume label or VFAT entry */
1037                                         dentptr++;
1038                                         continue;
1039                                 }
1040                         } else if (dentptr->name[0] == 0) {
1041                                 debug("RootDentname == NULL - %d\n", i);
1042                                 if (dols == LS_ROOT) {
1043                                         printf("\n%d file(s), %d dir(s)\n\n",
1044                                                 files, dirs);
1045                                         ret = 0;
1046                                 }
1047                                 goto exit;
1048                         }
1049                         else if (vfat_enabled &&
1050                                  dols == LS_ROOT && csum == prevcksum) {
1051                                 prevcksum = 0xffff;
1052                                 dentptr++;
1053                                 continue;
1054                         }
1055
1056                         get_name(dentptr, s_name);
1057
1058                         if (dols == LS_ROOT) {
1059                                 int isdir = (dentptr->attr & ATTR_DIR);
1060                                 char dirc;
1061                                 int doit = 0;
1062
1063                                 if (isdir) {
1064                                         dirc = '/';
1065                                         if (s_name[0] != 0) {
1066                                                 dirs++;
1067                                                 doit = 1;
1068                                         }
1069                                 } else {
1070                                         dirc = ' ';
1071                                         if (s_name[0] != 0) {
1072                                                 files++;
1073                                                 doit = 1;
1074                                         }
1075                                 }
1076                                 if (doit) {
1077                                         if (dirc == ' ') {
1078                                                 printf(" %8u   %s%c\n",
1079                                                        FAT2CPU32(dentptr->size),
1080                                                         s_name, dirc);
1081                                         } else {
1082                                                 printf("            %s%c\n",
1083                                                         s_name, dirc);
1084                                         }
1085                                 }
1086                                 dentptr++;
1087                                 continue;
1088                         }
1089
1090                         if (strcmp(fnamecopy, s_name)
1091                             && strcmp(fnamecopy, l_name)) {
1092                                 debug("RootMismatch: |%s|%s|\n", s_name,
1093                                        l_name);
1094                                 dentptr++;
1095                                 continue;
1096                         }
1097
1098                         if (isdir && !(dentptr->attr & ATTR_DIR))
1099                                 goto exit;
1100
1101                         debug("RootName: %s", s_name);
1102                         debug(", start: 0x%x", START(dentptr));
1103                         debug(", size:  0x%x %s\n",
1104                                FAT2CPU32(dentptr->size),
1105                                isdir ? "(DIR)" : "");
1106
1107                         goto rootdir_done;      /* We got a match */
1108                 }
1109                 debug("END LOOP: buffer_blk_cnt=%d   clust_size=%d\n", buffer_blk_cnt,
1110                        mydata->clust_size);
1111
1112                 /*
1113                  * On FAT32 we must fetch the FAT entries for the next
1114                  * root directory clusters when a cluster has been
1115                  * completely processed.
1116                  */
1117                 ++buffer_blk_cnt;
1118                 int rootdir_end = 0;
1119                 if (mydata->fatsize == 32) {
1120                         if (buffer_blk_cnt == mydata->clust_size) {
1121                                 int nxtsect = 0;
1122                                 int nxt_clust = 0;
1123
1124                                 nxt_clust = get_fatent(mydata, root_cluster);
1125                                 rootdir_end = CHECK_CLUST(nxt_clust, 32);
1126
1127                                 nxtsect = mydata->data_begin +
1128                                         (nxt_clust * mydata->clust_size);
1129
1130                                 root_cluster = nxt_clust;
1131
1132                                 cursect = nxtsect;
1133                                 buffer_blk_cnt = 0;
1134                         }
1135                 } else {
1136                         if (buffer_blk_cnt == PREFETCH_BLOCKS)
1137                                 buffer_blk_cnt = 0;
1138
1139                         rootdir_end = (++cursect - mydata->rootdir_sect >=
1140                                        rootdir_size);
1141                 }
1142
1143                 /* If end of rootdir reached */
1144                 if (rootdir_end) {
1145                         if (dols == LS_ROOT) {
1146                                 printf("\n%d file(s), %d dir(s)\n\n",
1147                                        files, dirs);
1148                                 *size = 0;
1149                         }
1150                         goto exit;
1151                 }
1152         }
1153 rootdir_done:
1154
1155         firsttime = 1;
1156
1157         while (isdir) {
1158                 int startsect = mydata->data_begin
1159                         + START(dentptr) * mydata->clust_size;
1160                 dir_entry dent;
1161                 char *nextname = NULL;
1162
1163                 dent = *dentptr;
1164                 dentptr = &dent;
1165
1166                 idx = dirdelim(subname);
1167
1168                 if (idx >= 0) {
1169                         subname[idx] = '\0';
1170                         nextname = subname + idx + 1;
1171                         /* Handle multiple delimiters */
1172                         while (ISDIRDELIM(*nextname))
1173                                 nextname++;
1174                         if (dols && *nextname == '\0')
1175                                 firsttime = 0;
1176                 } else {
1177                         if (dols && firsttime) {
1178                                 firsttime = 0;
1179                         } else {
1180                                 isdir = 0;
1181                         }
1182                 }
1183
1184                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1185                                      isdir ? 0 : dols) == NULL) {
1186                         if (dols && !isdir)
1187                                 *size = 0;
1188                         goto exit;
1189                 }
1190
1191                 if (isdir && !(dentptr->attr & ATTR_DIR))
1192                         goto exit;
1193
1194                 /*
1195                  * If we are looking for a directory, and found a directory
1196                  * type entry, and the entry is for the root directory (as
1197                  * denoted by a cluster number of 0), jump back to the start
1198                  * of the function, since at least on FAT12/16, the root dir
1199                  * lives in a hard-coded location and needs special handling
1200                  * to parse, rather than simply following the cluster linked
1201                  * list in the FAT, like other directories.
1202                  */
1203                 if (isdir && (dentptr->attr & ATTR_DIR) && !START(dentptr)) {
1204                         /*
1205                          * Modify the filename to remove the prefix that gets
1206                          * back to the root directory, so the initial root dir
1207                          * parsing code can continue from where we are without
1208                          * confusion.
1209                          */
1210                         strcpy(fnamecopy, nextname ?: "");
1211                         /*
1212                          * Set up state the same way as the function does when
1213                          * first started. This is required for the root dir
1214                          * parsing code operates in its expected environment.
1215                          */
1216                         subname = "";
1217                         cursect = mydata->rootdir_sect;
1218                         isdir = 0;
1219                         goto root_reparse;
1220                 }
1221
1222                 if (idx >= 0)
1223                         subname = nextname;
1224         }
1225
1226         if (dogetsize) {
1227                 *size = FAT2CPU32(dentptr->size);
1228                 ret = 0;
1229         } else {
1230                 ret = get_contents(mydata, dentptr, pos, buffer, maxsize, size);
1231         }
1232         debug("Size: %u, got: %llu\n", FAT2CPU32(dentptr->size), *size);
1233
1234 exit:
1235         free(mydata->fatbuf);
1236         return ret;
1237 }
1238
1239 int do_fat_read(const char *filename, void *buffer, loff_t maxsize, int dols,
1240                 loff_t *actread)
1241 {
1242         return do_fat_read_at(filename, 0, buffer, maxsize, dols, 0, actread);
1243 }
1244
1245 int file_fat_detectfs(void)
1246 {
1247         boot_sector bs;
1248         volume_info volinfo;
1249         int fatsize;
1250         char vol_label[12];
1251
1252         if (cur_dev == NULL) {
1253                 printf("No current device\n");
1254                 return 1;
1255         }
1256
1257 #if defined(CONFIG_CMD_IDE) || \
1258     defined(CONFIG_CMD_SATA) || \
1259     defined(CONFIG_SCSI) || \
1260     defined(CONFIG_CMD_USB) || \
1261     defined(CONFIG_MMC)
1262         printf("Interface:  ");
1263         switch (cur_dev->if_type) {
1264         case IF_TYPE_IDE:
1265                 printf("IDE");
1266                 break;
1267         case IF_TYPE_SATA:
1268                 printf("SATA");
1269                 break;
1270         case IF_TYPE_SCSI:
1271                 printf("SCSI");
1272                 break;
1273         case IF_TYPE_ATAPI:
1274                 printf("ATAPI");
1275                 break;
1276         case IF_TYPE_USB:
1277                 printf("USB");
1278                 break;
1279         case IF_TYPE_DOC:
1280                 printf("DOC");
1281                 break;
1282         case IF_TYPE_MMC:
1283                 printf("MMC");
1284                 break;
1285         default:
1286                 printf("Unknown");
1287         }
1288
1289         printf("\n  Device %d: ", cur_dev->devnum);
1290         dev_print(cur_dev);
1291 #endif
1292
1293         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1294                 printf("\nNo valid FAT fs found\n");
1295                 return 1;
1296         }
1297
1298         memcpy(vol_label, volinfo.volume_label, 11);
1299         vol_label[11] = '\0';
1300         volinfo.fs_type[5] = '\0';
1301
1302         printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
1303
1304         return 0;
1305 }
1306
1307 int file_fat_ls(const char *dir)
1308 {
1309         loff_t size;
1310
1311         return do_fat_read(dir, NULL, 0, LS_YES, &size);
1312 }
1313
1314 int fat_exists(const char *filename)
1315 {
1316         int ret;
1317         loff_t size;
1318
1319         ret = do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, &size);
1320         return ret == 0;
1321 }
1322
1323 int fat_size(const char *filename, loff_t *size)
1324 {
1325         return do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, size);
1326 }
1327
1328 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
1329                      loff_t maxsize, loff_t *actread)
1330 {
1331         printf("reading %s\n", filename);
1332         return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO, 0,
1333                               actread);
1334 }
1335
1336 int file_fat_read(const char *filename, void *buffer, int maxsize)
1337 {
1338         loff_t actread;
1339         int ret;
1340
1341         ret =  file_fat_read_at(filename, 0, buffer, maxsize, &actread);
1342         if (ret)
1343                 return ret;
1344         else
1345                 return actread;
1346 }
1347
1348 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
1349                   loff_t *actread)
1350 {
1351         int ret;
1352
1353         ret = file_fat_read_at(filename, offset, buf, len, actread);
1354         if (ret)
1355                 printf("** Unable to read file %s **\n", filename);
1356
1357         return ret;
1358 }
1359
1360 void fat_close(void)
1361 {
1362 }