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 off16, offset;
 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                 off16 = (offset * 3) / 2;
 246                 ret = FAT2CPU16(*(__u16 *)(mydata->fatbuf + off16));
 247
 248                 if (offset & 0x1)
 249                         ret >>= 4;
 250                 ret &= 0xfff;
 251         }
 252         debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
 253                mydata->fatsize, ret, entry, offset);
 254
 255         return ret;
 256 }
 257
 258 /*
 259  * Read at most 'size' bytes from the specified cluster into 'buffer'.
 260  * Return 0 on success, -1 otherwise.
 261  */
 262 static int
 263 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
 264 {
 265         __u32 idx = 0;
 266         __u32 startsect;
 267         int ret;
 268
 269         if (clustnum > 0) {
 270                 startsect = mydata->data_begin +
 271                                 clustnum * mydata->clust_size;
 272         } else {
 273                 startsect = mydata->rootdir_sect;
 274         }
 275
 276         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 277
 278         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 279                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 280
 281                 printf("FAT: Misaligned buffer address (%p)\n", buffer);
 282
 283                 while (size >= mydata->sect_size) {
 284                         ret = disk_read(startsect++, 1, tmpbuf);
 285                         if (ret != 1) {
 286                                 debug("Error reading data (got %d)\n", ret);
 287                                 return -1;
 288                         }
 289
 290                         memcpy(buffer, tmpbuf, mydata->sect_size);
 291                         buffer += mydata->sect_size;
 292                         size -= mydata->sect_size;
 293                 }
 294         } else {
 295                 idx = size / mydata->sect_size;
 296                 ret = disk_read(startsect, idx, buffer);
 297                 if (ret != idx) {
 298                         debug("Error reading data (got %d)\n", ret);
 299                         return -1;
 300                 }
 301                 startsect += idx;
 302                 idx *= mydata->sect_size;
 303                 buffer += idx;
 304                 size -= idx;
 305         }
 306         if (size) {
 307                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 308
 309                 ret = disk_read(startsect, 1, tmpbuf);
 310                 if (ret != 1) {
 311                         debug("Error reading data (got %d)\n", ret);
 312                         return -1;
 313                 }
 314
 315                 memcpy(buffer, tmpbuf, size);
 316         }
 317
 318         return 0;
 319 }
 320
 321 /*
 322  * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
 323  * into 'buffer'.
 324  * Update the number of bytes read in *gotsize or return -1 on fatal errors.
 325  */
 326 __u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
 327         __aligned(ARCH_DMA_MINALIGN);
 328
 329 static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
 330                         __u8 *buffer, loff_t maxsize, loff_t *gotsize)
 331 {
 332         loff_t filesize = FAT2CPU32(dentptr->size);
 333         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 334         __u32 curclust = START(dentptr);
 335         __u32 endclust, newclust;
 336         loff_t actsize;
 337
 338         *gotsize = 0;
 339         debug("Filesize: %llu bytes\n", filesize);
 340
 341         if (pos >= filesize) {
 342                 debug("Read position past EOF: %llu\n", pos);
 343                 return 0;
 344         }
 345
 346         if (maxsize > 0 && filesize > pos + maxsize)
 347                 filesize = pos + maxsize;
 348
 349         debug("%llu bytes\n", filesize);
 350
 351         actsize = bytesperclust;
 352
 353         /* go to cluster at pos */
 354         while (actsize <= pos) {
 355                 curclust = get_fatent(mydata, curclust);
 356                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 357                         debug("curclust: 0x%x\n", curclust);
 358                         debug("Invalid FAT entry\n");
 359                         return 0;
 360                 }
 361                 actsize += bytesperclust;
 362         }
 363
 364         /* actsize > pos */
 365         actsize -= bytesperclust;
 366         filesize -= actsize;
 367         pos -= actsize;
 368
 369         /* align to beginning of next cluster if any */
 370         if (pos) {
 371                 actsize = min(filesize, (loff_t)bytesperclust);
 372                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 373                                 (int)actsize) != 0) {
 374                         printf("Error reading cluster\n");
 375                         return -1;
 376                 }
 377                 filesize -= actsize;
 378                 actsize -= pos;
 379                 memcpy(buffer, get_contents_vfatname_block + pos, actsize);
 380                 *gotsize += actsize;
 381                 if (!filesize)
 382                         return 0;
 383                 buffer += actsize;
 384
 385                 curclust = get_fatent(mydata, curclust);
 386                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 387                         debug("curclust: 0x%x\n", curclust);
 388                         debug("Invalid FAT entry\n");
 389                         return 0;
 390                 }
 391         }
 392
 393         actsize = bytesperclust;
 394         endclust = curclust;
 395
 396         do {
 397                 /* search for consecutive clusters */
 398                 while (actsize < filesize) {
 399                         newclust = get_fatent(mydata, endclust);
 400                         if ((newclust - 1) != endclust)
 401                                 goto getit;
 402                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 403                                 debug("curclust: 0x%x\n", newclust);
 404                                 debug("Invalid FAT entry\n");
 405                                 return 0;
 406                         }
 407                         endclust = newclust;
 408                         actsize += bytesperclust;
 409                 }
 410
 411                 /* get remaining bytes */
 412                 actsize = filesize;
 413                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 414                         printf("Error reading cluster\n");
 415                         return -1;
 416                 }
 417                 *gotsize += actsize;
 418                 return 0;
 419 getit:
 420                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 421                         printf("Error reading cluster\n");
 422                         return -1;
 423                 }
 424                 *gotsize += (int)actsize;
 425                 filesize -= actsize;
 426                 buffer += actsize;
 427
 428                 curclust = get_fatent(mydata, endclust);
 429                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 430                         debug("curclust: 0x%x\n", curclust);
 431                         printf("Invalid FAT entry\n");
 432                         return 0;
 433                 }
 434                 actsize = bytesperclust;
 435                 endclust = curclust;
 436         } while (1);
 437 }
 438
 439 /*
 440  * Extract the file name information from 'slotptr' into 'l_name',
 441  * starting at l_name[*idx].
 442  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 443  */
 444 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
 445 {
 446         int j;
 447
 448         for (j = 0; j <= 8; j += 2) {
 449                 l_name[*idx] = slotptr->name0_4[j];
 450                 if (l_name[*idx] == 0x00)
 451                         return 1;
 452                 (*idx)++;
 453         }
 454         for (j = 0; j <= 10; j += 2) {
 455                 l_name[*idx] = slotptr->name5_10[j];
 456                 if (l_name[*idx] == 0x00)
 457                         return 1;
 458                 (*idx)++;
 459         }
 460         for (j = 0; j <= 2; j += 2) {
 461                 l_name[*idx] = slotptr->name11_12[j];
 462                 if (l_name[*idx] == 0x00)
 463                         return 1;
 464                 (*idx)++;
 465         }
 466
 467         return 0;
 468 }
 469
 470 /*
 471  * Extract the full long filename starting at 'retdent' (which is really
 472  * a slot) into 'l_name'. If successful also copy the real directory entry
 473  * into 'retdent'
 474  * Return 0 on success, -1 otherwise.
 475  */
 476 static int
 477 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 478              dir_entry *retdent, char *l_name)
 479 {
 480         dir_entry *realdent;
 481         dir_slot *slotptr = (dir_slot *)retdent;
 482         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 483                                                         PREFETCH_BLOCKS :
 484                                                         mydata->clust_size);
 485         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 486         int idx = 0;
 487
 488         if (counter > VFAT_MAXSEQ) {
 489                 debug("Error: VFAT name is too long\n");
 490                 return -1;
 491         }
 492
 493         while ((__u8 *)slotptr < buflimit) {
 494                 if (counter == 0)
 495                         break;
 496                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 497                         return -1;
 498                 slotptr++;
 499                 counter--;
 500         }
 501
 502         if ((__u8 *)slotptr >= buflimit) {
 503                 dir_slot *slotptr2;
 504
 505                 if (curclust == 0)
 506                         return -1;
 507                 curclust = get_fatent(mydata, curclust);
 508                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 509                         debug("curclust: 0x%x\n", curclust);
 510                         printf("Invalid FAT entry\n");
 511                         return -1;
 512                 }
 513
 514                 if (get_cluster(mydata, curclust, get_contents_vfatname_block,
 515                                 mydata->clust_size * mydata->sect_size) != 0) {
 516                         debug("Error: reading directory block\n");
 517                         return -1;
 518                 }
 519
 520                 slotptr2 = (dir_slot *)get_contents_vfatname_block;
 521                 while (counter > 0) {
 522                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 523                             & 0xff) != counter)
 524                                 return -1;
 525                         slotptr2++;
 526                         counter--;
 527                 }
 528
 529                 /* Save the real directory entry */
 530                 realdent = (dir_entry *)slotptr2;
 531                 while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
 532                         slotptr2--;
 533                         slot2str(slotptr2, l_name, &idx);
 534                 }
 535         } else {
 536                 /* Save the real directory entry */
 537                 realdent = (dir_entry *)slotptr;
 538         }
 539
 540         do {
 541                 slotptr--;
 542                 if (slot2str(slotptr, l_name, &idx))
 543                         break;
 544         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 545
 546         l_name[idx] = '\0';
 547         if (*l_name == DELETED_FLAG)
 548                 *l_name = '\0';
 549         else if (*l_name == aRING)
 550                 *l_name = DELETED_FLAG;
 551         downcase(l_name);
 552
 553         /* Return the real directory entry */
 554         memcpy(retdent, realdent, sizeof(dir_entry));
 555
 556         return 0;
 557 }
 558
 559 /* Calculate short name checksum */
 560 static __u8 mkcksum(const char name[8], const char ext[3])
 561 {
 562         int i;
 563
 564         __u8 ret = 0;
 565
 566         for (i = 0; i < 8; i++)
 567                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
 568         for (i = 0; i < 3; i++)
 569                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
 570
 571         return ret;
 572 }
 573
 574 /*
 575  * Get the directory entry associated with 'filename' from the directory
 576  * starting at 'startsect'
 577  */
 578 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
 579         __aligned(ARCH_DMA_MINALIGN);
 580
 581 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
 582                                   char *filename, dir_entry *retdent,
 583                                   int dols)
 584 {
 585         __u16 prevcksum = 0xffff;
 586         __u32 curclust = START(retdent);
 587         int files = 0, dirs = 0;
 588
 589         debug("get_dentfromdir: %s\n", filename);
 590
 591         while (1) {
 592                 dir_entry *dentptr;
 593
 594                 int i;
 595
 596                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 597                                 mydata->clust_size * mydata->sect_size) != 0) {
 598                         debug("Error: reading directory block\n");
 599                         return NULL;
 600                 }
 601
 602                 dentptr = (dir_entry *)get_dentfromdir_block;
 603
 604                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 605                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 606
 607                         l_name[0] = '\0';
 608                         if (dentptr->name[0] == DELETED_FLAG) {
 609                                 dentptr++;
 610                                 continue;
 611                         }
 612                         if ((dentptr->attr & ATTR_VOLUME)) {
 613                                 if (vfat_enabled &&
 614                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 615                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 616                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 617                                         get_vfatname(mydata, curclust,
 618                                                      get_dentfromdir_block,
 619                                                      dentptr, l_name);
 620                                         if (dols) {
 621                                                 int isdir;
 622                                                 char dirc;
 623                                                 int doit = 0;
 624
 625                                                 isdir = (dentptr->attr & ATTR_DIR);
 626
 627                                                 if (isdir) {
 628                                                         dirs++;
 629                                                         dirc = '/';
 630                                                         doit = 1;
 631                                                 } else {
 632                                                         dirc = ' ';
 633                                                         if (l_name[0] != 0) {
 634                                                                 files++;
 635                                                                 doit = 1;
 636                                                         }
 637                                                 }
 638                                                 if (doit) {
 639                                                         if (dirc == ' ') {
 640                                                                 printf(" %8u   %s%c\n",
 641                                                                        FAT2CPU32(dentptr->size),
 642                                                                         l_name,
 643                                                                         dirc);
 644                                                         } else {
 645                                                                 printf("            %s%c\n",
 646                                                                         l_name,
 647                                                                         dirc);
 648                                                         }
 649                                                 }
 650                                                 dentptr++;
 651                                                 continue;
 652                                         }
 653                                         debug("vfatname: |%s|\n", l_name);
 654                                 } else {
 655                                         /* Volume label or VFAT entry */
 656                                         dentptr++;
 657                                         continue;
 658                                 }
 659                         }
 660                         if (dentptr->name[0] == 0) {
 661                                 if (dols) {
 662                                         printf("\n%d file(s), %d dir(s)\n\n",
 663                                                 files, dirs);
 664                                 }
 665                                 debug("Dentname == NULL - %d\n", i);
 666                                 return NULL;
 667                         }
 668                         if (vfat_enabled) {
 669                                 __u8 csum = mkcksum(dentptr->name, dentptr->ext);
 670                                 if (dols && csum == prevcksum) {
 671                                         prevcksum = 0xffff;
 672                                         dentptr++;
 673                                         continue;
 674                                 }
 675                         }
 676
 677                         get_name(dentptr, s_name);
 678                         if (dols) {
 679                                 int isdir = (dentptr->attr & ATTR_DIR);
 680                                 char dirc;
 681                                 int doit = 0;
 682
 683                                 if (isdir) {
 684                                         dirs++;
 685                                         dirc = '/';
 686                                         doit = 1;
 687                                 } else {
 688                                         dirc = ' ';
 689                                         if (s_name[0] != 0) {
 690                                                 files++;
 691                                                 doit = 1;
 692                                         }
 693                                 }
 694
 695                                 if (doit) {
 696                                         if (dirc == ' ') {
 697                                                 printf(" %8u   %s%c\n",
 698                                                        FAT2CPU32(dentptr->size),
 699                                                         s_name, dirc);
 700                                         } else {
 701                                                 printf("            %s%c\n",
 702                                                         s_name, dirc);
 703                                         }
 704                                 }
 705
 706                                 dentptr++;
 707                                 continue;
 708                         }
 709
 710                         if (strcmp(filename, s_name)
 711                             && strcmp(filename, l_name)) {
 712                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 713                                 dentptr++;
 714                                 continue;
 715                         }
 716
 717                         memcpy(retdent, dentptr, sizeof(dir_entry));
 718
 719                         debug("DentName: %s", s_name);
 720                         debug(", start: 0x%x", START(dentptr));
 721                         debug(", size:  0x%x %s\n",
 722                               FAT2CPU32(dentptr->size),
 723                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 724
 725                         return retdent;
 726                 }
 727
 728                 curclust = get_fatent(mydata, curclust);
 729                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 730                         debug("curclust: 0x%x\n", curclust);
 731                         printf("Invalid FAT entry\n");
 732                         return NULL;
 733                 }
 734         }
 735
 736         return NULL;
 737 }
 738
 739 /*
 740  * Read boot sector and volume info from a FAT filesystem
 741  */
 742 static int
 743 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 744 {
 745         __u8 *block;
 746         volume_info *vistart;
 747         int ret = 0;
 748
 749         if (cur_dev == NULL) {
 750                 debug("Error: no device selected\n");
 751                 return -1;
 752         }
 753
 754         block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
 755         if (block == NULL) {
 756                 debug("Error: allocating block\n");
 757                 return -1;
 758         }
 759
 760         if (disk_read(0, 1, block) < 0) {
 761                 debug("Error: reading block\n");
 762                 goto fail;
 763         }
 764
 765         memcpy(bs, block, sizeof(boot_sector));
 766         bs->reserved = FAT2CPU16(bs->reserved);
 767         bs->fat_length = FAT2CPU16(bs->fat_length);
 768         bs->secs_track = FAT2CPU16(bs->secs_track);
 769         bs->heads = FAT2CPU16(bs->heads);
 770         bs->total_sect = FAT2CPU32(bs->total_sect);
 771
 772         /* FAT32 entries */
 773         if (bs->fat_length == 0) {
 774                 /* Assume FAT32 */
 775                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 776                 bs->flags = FAT2CPU16(bs->flags);
 777                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 778                 bs->info_sector = FAT2CPU16(bs->info_sector);
 779                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 780                 vistart = (volume_info *)(block + sizeof(boot_sector));
 781                 *fatsize = 32;
 782         } else {
 783                 vistart = (volume_info *)&(bs->fat32_length);
 784                 *fatsize = 0;
 785         }
 786         memcpy(volinfo, vistart, sizeof(volume_info));
 787
 788         if (*fatsize == 32) {
 789                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 790                         goto exit;
 791         } else {
 792                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 793                         *fatsize = 12;
 794                         goto exit;
 795                 }
 796                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 797                         *fatsize = 16;
 798                         goto exit;
 799                 }
 800         }
 801
 802         debug("Error: broken fs_type sign\n");
 803 fail:
 804         ret = -1;
 805 exit:
 806         free(block);
 807         return ret;
 808 }
 809
 810 __u8 do_fat_read_at_block[MAX_CLUSTSIZE]
 811         __aligned(ARCH_DMA_MINALIGN);
 812
 813 int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
 814                    loff_t maxsize, int dols, int dogetsize, loff_t *size)
 815 {
 816         char fnamecopy[2048];
 817         boot_sector bs;
 818         volume_info volinfo;
 819         fsdata datablock;
 820         fsdata *mydata = &datablock;
 821         dir_entry *dentptr = NULL;
 822         __u16 prevcksum = 0xffff;
 823         char *subname = "";
 824         __u32 cursect;
 825         int idx, isdir = 0;
 826         int files = 0, dirs = 0;
 827         int ret = -1;
 828         int firsttime;
 829         __u32 root_cluster = 0;
 830         __u32 read_blk;
 831         int rootdir_size = 0;
 832         int buffer_blk_cnt;
 833         int do_read;
 834         __u8 *dir_ptr;
 835
 836         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 837                 debug("Error: reading boot sector\n");
 838                 return -1;
 839         }
 840
 841         if (mydata->fatsize == 32) {
 842                 root_cluster = bs.root_cluster;
 843                 mydata->fatlength = bs.fat32_length;
 844         } else {
 845                 mydata->fatlength = bs.fat_length;
 846         }
 847
 848         mydata->fat_sect = bs.reserved;
 849
 850         cursect = mydata->rootdir_sect
 851                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 852
 853         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 854         mydata->clust_size = bs.cluster_size;
 855         if (mydata->sect_size != cur_part_info.blksz) {
 856                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 857                                 mydata->sect_size, cur_part_info.blksz);
 858                 return -1;
 859         }
 860
 861         if (mydata->fatsize == 32) {
 862                 mydata->data_begin = mydata->rootdir_sect -
 863                                         (mydata->clust_size * 2);
 864         } else {
 865                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 866                                  bs.dir_entries[0]) *
 867                                  sizeof(dir_entry)) /
 868                                  mydata->sect_size;
 869                 mydata->data_begin = mydata->rootdir_sect +
 870                                         rootdir_size -
 871                                         (mydata->clust_size * 2);
 872         }
 873
 874         mydata->fatbufnum = -1;
 875         mydata->fat_dirty = 0;
 876         mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
 877         if (mydata->fatbuf == NULL) {
 878                 debug("Error: allocating memory\n");
 879                 return -1;
 880         }
 881
 882         if (vfat_enabled)
 883                 debug("VFAT Support enabled\n");
 884
 885         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 886                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 887         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 888                "Data begins at: %d\n",
 889                root_cluster,
 890                mydata->rootdir_sect,
 891                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 892         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 893               mydata->clust_size);
 894
 895         /* "cwd" is always the root... */
 896         while (ISDIRDELIM(*filename))
 897                 filename++;
 898
 899         /* Make a copy of the filename and convert it to lowercase */
 900         strcpy(fnamecopy, filename);
 901         downcase(fnamecopy);
 902
 903 root_reparse:
 904         if (*fnamecopy == '\0') {
 905                 if (!dols)
 906                         goto exit;
 907
 908                 dols = LS_ROOT;
 909         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 910                 isdir = 1;
 911                 fnamecopy[idx] = '\0';
 912                 subname = fnamecopy + idx + 1;
 913
 914                 /* Handle multiple delimiters */
 915                 while (ISDIRDELIM(*subname))
 916                         subname++;
 917         } else if (dols) {
 918                 isdir = 1;
 919         }
 920
 921         buffer_blk_cnt = 0;
 922         firsttime = 1;
 923         while (1) {
 924                 int i;
 925
 926                 if (mydata->fatsize == 32 || firsttime) {
 927                         dir_ptr = do_fat_read_at_block;
 928                         firsttime = 0;
 929                 } else {
 930                         /**
 931                          * FAT16 sector buffer modification:
 932                          * Each loop, the second buffered block is moved to
 933                          * the buffer begin, and two next sectors are read
 934                          * next to the previously moved one. So the sector
 935                          * buffer keeps always 3 sectors for fat16.
 936                          * And the current sector is the buffer second sector
 937                          * beside the "firsttime" read, when it is the first one.
 938                          *
 939                          * PREFETCH_BLOCKS is 2 for FAT16 == loop[0:1]
 940                          * n = computed root dir sector
 941                          * loop |  cursect-1  | cursect    | cursect+1  |
 942                          *   0  |  sector n+0 | sector n+1 | none       |
 943                          *   1  |  none       | sector n+0 | sector n+1 |
 944                          *   0  |  sector n+1 | sector n+2 | sector n+3 |
 945                          *   1  |  sector n+3 | ...
 946                         */
 947                         dir_ptr = (do_fat_read_at_block + mydata->sect_size);
 948                         memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
 949                 }
 950
 951                 do_read = 1;
 952
 953                 if (mydata->fatsize == 32 && buffer_blk_cnt)
 954                         do_read = 0;
 955
 956                 if (do_read) {
 957                         read_blk = (mydata->fatsize == 32) ?
 958                                     mydata->clust_size : PREFETCH_BLOCKS;
 959
 960                         debug("FAT read(sect=%d, cnt:%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 961                                 cursect, read_blk, mydata->clust_size, DIRENTSPERBLOCK);
 962
 963                         if (disk_read(cursect, read_blk, dir_ptr) < 0) {
 964                                 debug("Error: reading rootdir block\n");
 965                                 goto exit;
 966                         }
 967
 968                         dentptr = (dir_entry *)dir_ptr;
 969                 }
 970
 971                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 972                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 973                         __u8 csum;
 974
 975                         l_name[0] = '\0';
 976                         if (dentptr->name[0] == DELETED_FLAG) {
 977                                 dentptr++;
 978                                 continue;
 979                         }
 980
 981                         if (vfat_enabled)
 982                                 csum = mkcksum(dentptr->name, dentptr->ext);
 983
 984                         if (dentptr->attr & ATTR_VOLUME) {
 985                                 if (vfat_enabled &&
 986                                     (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 987                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 988                                         prevcksum =
 989                                                 ((dir_slot *)dentptr)->alias_checksum;
 990
 991                                         get_vfatname(mydata,
 992                                                      root_cluster,
 993                                                      dir_ptr,
 994                                                      dentptr, l_name);
 995
 996                                         if (dols == LS_ROOT) {
 997                                                 char dirc;
 998                                                 int doit = 0;
 999                                                 int isdir =
1000                                                         (dentptr->attr & ATTR_DIR);
1001
1002                                                 if (isdir) {
1003                                                         dirs++;
1004                                                         dirc = '/';
1005                                                         doit = 1;
1006                                                 } else {
1007                                                         dirc = ' ';
1008                                                         if (l_name[0] != 0) {
1009                                                                 files++;
1010                                                                 doit = 1;
1011                                                         }
1012                                                 }
1013                                                 if (doit) {
1014                                                         if (dirc == ' ') {
1015                                                                 printf(" %8u   %s%c\n",
1016                                                                        FAT2CPU32(dentptr->size),
1017                                                                         l_name,
1018                                                                         dirc);
1019                                                         } else {
1020                                                                 printf("            %s%c\n",
1021                                                                         l_name,
1022                                                                         dirc);
1023                                                         }
1024                                                 }
1025                                                 dentptr++;
1026                                                 continue;
1027                                         }
1028                                         debug("Rootvfatname: |%s|\n",
1029                                                l_name);
1030                                 } else {
1031                                         /* Volume label or VFAT entry */
1032                                         dentptr++;
1033                                         continue;
1034                                 }
1035                         } else if (dentptr->name[0] == 0) {
1036                                 debug("RootDentname == NULL - %d\n", i);
1037                                 if (dols == LS_ROOT) {
1038                                         printf("\n%d file(s), %d dir(s)\n\n",
1039                                                 files, dirs);
1040                                         ret = 0;
1041                                 }
1042                                 goto exit;
1043                         }
1044                         else if (vfat_enabled &&
1045                                  dols == LS_ROOT && csum == prevcksum) {
1046                                 prevcksum = 0xffff;
1047                                 dentptr++;
1048                                 continue;
1049                         }
1050
1051                         get_name(dentptr, s_name);
1052
1053                         if (dols == LS_ROOT) {
1054                                 int isdir = (dentptr->attr & ATTR_DIR);
1055                                 char dirc;
1056                                 int doit = 0;
1057
1058                                 if (isdir) {
1059                                         dirc = '/';
1060                                         if (s_name[0] != 0) {
1061                                                 dirs++;
1062                                                 doit = 1;
1063                                         }
1064                                 } else {
1065                                         dirc = ' ';
1066                                         if (s_name[0] != 0) {
1067                                                 files++;
1068                                                 doit = 1;
1069                                         }
1070                                 }
1071                                 if (doit) {
1072                                         if (dirc == ' ') {
1073                                                 printf(" %8u   %s%c\n",
1074                                                        FAT2CPU32(dentptr->size),
1075                                                         s_name, dirc);
1076                                         } else {
1077                                                 printf("            %s%c\n",
1078                                                         s_name, dirc);
1079                                         }
1080                                 }
1081                                 dentptr++;
1082                                 continue;
1083                         }
1084
1085                         if (strcmp(fnamecopy, s_name)
1086                             && strcmp(fnamecopy, l_name)) {
1087                                 debug("RootMismatch: |%s|%s|\n", s_name,
1088                                        l_name);
1089                                 dentptr++;
1090                                 continue;
1091                         }
1092
1093                         if (isdir && !(dentptr->attr & ATTR_DIR))
1094                                 goto exit;
1095
1096                         debug("RootName: %s", s_name);
1097                         debug(", start: 0x%x", START(dentptr));
1098                         debug(", size:  0x%x %s\n",
1099                                FAT2CPU32(dentptr->size),
1100                                isdir ? "(DIR)" : "");
1101
1102                         goto rootdir_done;      /* We got a match */
1103                 }
1104                 debug("END LOOP: buffer_blk_cnt=%d   clust_size=%d\n", buffer_blk_cnt,
1105                        mydata->clust_size);
1106
1107                 /*
1108                  * On FAT32 we must fetch the FAT entries for the next
1109                  * root directory clusters when a cluster has been
1110                  * completely processed.
1111                  */
1112                 ++buffer_blk_cnt;
1113                 int rootdir_end = 0;
1114                 if (mydata->fatsize == 32) {
1115                         if (buffer_blk_cnt == mydata->clust_size) {
1116                                 int nxtsect = 0;
1117                                 int nxt_clust = 0;
1118
1119                                 nxt_clust = get_fatent(mydata, root_cluster);
1120                                 rootdir_end = CHECK_CLUST(nxt_clust, 32);
1121
1122                                 nxtsect = mydata->data_begin +
1123                                         (nxt_clust * mydata->clust_size);
1124
1125                                 root_cluster = nxt_clust;
1126
1127                                 cursect = nxtsect;
1128                                 buffer_blk_cnt = 0;
1129                         }
1130                 } else {
1131                         if (buffer_blk_cnt == PREFETCH_BLOCKS)
1132                                 buffer_blk_cnt = 0;
1133
1134                         rootdir_end = (++cursect - mydata->rootdir_sect >=
1135                                        rootdir_size);
1136                 }
1137
1138                 /* If end of rootdir reached */
1139                 if (rootdir_end) {
1140                         if (dols == LS_ROOT) {
1141                                 printf("\n%d file(s), %d dir(s)\n\n",
1142                                        files, dirs);
1143                                 *size = 0;
1144                         }
1145                         goto exit;
1146                 }
1147         }
1148 rootdir_done:
1149
1150         firsttime = 1;
1151
1152         while (isdir) {
1153                 int startsect = mydata->data_begin
1154                         + START(dentptr) * mydata->clust_size;
1155                 dir_entry dent;
1156                 char *nextname = NULL;
1157
1158                 dent = *dentptr;
1159                 dentptr = &dent;
1160
1161                 idx = dirdelim(subname);
1162
1163                 if (idx >= 0) {
1164                         subname[idx] = '\0';
1165                         nextname = subname + idx + 1;
1166                         /* Handle multiple delimiters */
1167                         while (ISDIRDELIM(*nextname))
1168                                 nextname++;
1169                         if (dols && *nextname == '\0')
1170                                 firsttime = 0;
1171                 } else {
1172                         if (dols && firsttime) {
1173                                 firsttime = 0;
1174                         } else {
1175                                 isdir = 0;
1176                         }
1177                 }
1178
1179                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1180                                      isdir ? 0 : dols) == NULL) {
1181                         if (dols && !isdir)
1182                                 *size = 0;
1183                         goto exit;
1184                 }
1185
1186                 if (isdir && !(dentptr->attr & ATTR_DIR))
1187                         goto exit;
1188
1189                 /*
1190                  * If we are looking for a directory, and found a directory
1191                  * type entry, and the entry is for the root directory (as
1192                  * denoted by a cluster number of 0), jump back to the start
1193                  * of the function, since at least on FAT12/16, the root dir
1194                  * lives in a hard-coded location and needs special handling
1195                  * to parse, rather than simply following the cluster linked
1196                  * list in the FAT, like other directories.
1197                  */
1198                 if (isdir && (dentptr->attr & ATTR_DIR) && !START(dentptr)) {
1199                         /*
1200                          * Modify the filename to remove the prefix that gets
1201                          * back to the root directory, so the initial root dir
1202                          * parsing code can continue from where we are without
1203                          * confusion.
1204                          */
1205                         strcpy(fnamecopy, nextname ?: "");
1206                         /*
1207                          * Set up state the same way as the function does when
1208                          * first started. This is required for the root dir
1209                          * parsing code operates in its expected environment.
1210                          */
1211                         subname = "";
1212                         cursect = mydata->rootdir_sect;
1213                         isdir = 0;
1214                         goto root_reparse;
1215                 }
1216
1217                 if (idx >= 0)
1218                         subname = nextname;
1219         }
1220
1221         if (dogetsize) {
1222                 *size = FAT2CPU32(dentptr->size);
1223                 ret = 0;
1224         } else {
1225                 ret = get_contents(mydata, dentptr, pos, buffer, maxsize, size);
1226         }
1227         debug("Size: %u, got: %llu\n", FAT2CPU32(dentptr->size), *size);
1228
1229 exit:
1230         free(mydata->fatbuf);
1231         return ret;
1232 }
1233
1234 int do_fat_read(const char *filename, void *buffer, loff_t maxsize, int dols,
1235                 loff_t *actread)
1236 {
1237         return do_fat_read_at(filename, 0, buffer, maxsize, dols, 0, actread);
1238 }
1239
1240 int file_fat_detectfs(void)
1241 {
1242         boot_sector bs;
1243         volume_info volinfo;
1244         int fatsize;
1245         char vol_label[12];
1246
1247         if (cur_dev == NULL) {
1248                 printf("No current device\n");
1249                 return 1;
1250         }
1251
1252 #if defined(CONFIG_CMD_IDE) || \
1253     defined(CONFIG_CMD_SATA) || \
1254     defined(CONFIG_SCSI) || \
1255     defined(CONFIG_CMD_USB) || \
1256     defined(CONFIG_MMC)
1257         printf("Interface:  ");
1258         switch (cur_dev->if_type) {
1259         case IF_TYPE_IDE:
1260                 printf("IDE");
1261                 break;
1262         case IF_TYPE_SATA:
1263                 printf("SATA");
1264                 break;
1265         case IF_TYPE_SCSI:
1266                 printf("SCSI");
1267                 break;
1268         case IF_TYPE_ATAPI:
1269                 printf("ATAPI");
1270                 break;
1271         case IF_TYPE_USB:
1272                 printf("USB");
1273                 break;
1274         case IF_TYPE_DOC:
1275                 printf("DOC");
1276                 break;
1277         case IF_TYPE_MMC:
1278                 printf("MMC");
1279                 break;
1280         default:
1281                 printf("Unknown");
1282         }
1283
1284         printf("\n  Device %d: ", cur_dev->devnum);
1285         dev_print(cur_dev);
1286 #endif
1287
1288         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1289                 printf("\nNo valid FAT fs found\n");
1290                 return 1;
1291         }
1292
1293         memcpy(vol_label, volinfo.volume_label, 11);
1294         vol_label[11] = '\0';
1295         volinfo.fs_type[5] = '\0';
1296
1297         printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
1298
1299         return 0;
1300 }
1301
1302 int file_fat_ls(const char *dir)
1303 {
1304         loff_t size;
1305
1306         return do_fat_read(dir, NULL, 0, LS_YES, &size);
1307 }
1308
1309 int fat_exists(const char *filename)
1310 {
1311         int ret;
1312         loff_t size;
1313
1314         ret = do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, &size);
1315         return ret == 0;
1316 }
1317
1318 int fat_size(const char *filename, loff_t *size)
1319 {
1320         return do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, size);
1321 }
1322
1323 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
1324                      loff_t maxsize, loff_t *actread)
1325 {
1326         printf("reading %s\n", filename);
1327         return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO, 0,
1328                               actread);
1329 }
1330
1331 int file_fat_read(const char *filename, void *buffer, int maxsize)
1332 {
1333         loff_t actread;
1334         int ret;
1335
1336         ret =  file_fat_read_at(filename, 0, buffer, maxsize, &actread);
1337         if (ret)
1338                 return ret;
1339         else
1340                 return actread;
1341 }
1342
1343 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
1344                   loff_t *actread)
1345 {
1346         int ret;
1347
1348         ret = file_fat_read_at(filename, offset, buf, len, actread);
1349         if (ret)
1350                 printf("** Unable to read file %s **\n", filename);
1351
1352         return ret;
1353 }
1354
1355 void fat_close(void)
1356 {
1357 }