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  * See file CREDITS for list of people who contributed to this
  10  * project.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License as
  14  * published by the Free Software Foundation; either version 2 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  25  * MA 02111-1307 USA
  26  */
  27
  28 #include <common.h>
  29 #include <config.h>
  30 #include <exports.h>
  31 #include <fat.h>
  32 #include <asm/byteorder.h>
  33 #include <part.h>
  34 #include <malloc.h>
  35 #include <linux/compiler.h>
  36
  37 /*
  38  * Convert a string to lowercase.
  39  */
  40 static void downcase(char *str)
  41 {
  42         while (*str != '\0') {
  43                 TOLOWER(*str);
  44                 str++;
  45         }
  46 }
  47
  48 static block_dev_desc_t *cur_dev;
  49 static unsigned int cur_part_nr;
  50 static disk_partition_t cur_part_info;
  51
  52 #define DOS_BOOT_MAGIC_OFFSET   0x1fe
  53 #define DOS_FS_TYPE_OFFSET      0x36
  54 #define DOS_FS32_TYPE_OFFSET    0x52
  55
  56 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
  57 {
  58         if (!cur_dev || !cur_dev->block_read)
  59                 return -1;
  60
  61         return cur_dev->block_read(cur_dev->dev,
  62                         cur_part_info.start + block, nr_blocks, buf);
  63 }
  64
  65 int fat_register_device(block_dev_desc_t * dev_desc, int part_no)
  66 {
  67         ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
  68
  69         /* First close any currently found FAT filesystem */
  70         cur_dev = NULL;
  71
  72 #if (defined(CONFIG_CMD_IDE) || \
  73      defined(CONFIG_CMD_SATA) || \
  74      defined(CONFIG_CMD_SCSI) || \
  75      defined(CONFIG_CMD_USB) || \
  76      defined(CONFIG_MMC) || \
  77      defined(CONFIG_SYSTEMACE) )
  78
  79         /* Read the partition table, if present */
  80         if (!get_partition_info(dev_desc, part_no, &cur_part_info)) {
  81                 cur_dev = dev_desc;
  82                 cur_part_nr = part_no;
  83         }
  84 #endif
  85
  86         /* Otherwise it might be a superfloppy (whole-disk FAT filesystem) */
  87         if (!cur_dev) {
  88                 if (part_no != 1) {
  89                         printf("** Partition %d not valid on device %d **\n",
  90                                         part_no, dev_desc->dev);
  91                         return -1;
  92                 }
  93
  94                 cur_dev = dev_desc;
  95                 cur_part_nr = 1;
  96                 cur_part_info.start = 0;
  97                 cur_part_info.size = dev_desc->lba;
  98                 cur_part_info.blksz = dev_desc->blksz;
  99                 memset(cur_part_info.name, 0, sizeof(cur_part_info.name));
 100                 memset(cur_part_info.type, 0, sizeof(cur_part_info.type));
 101         }
 102
 103         /* Make sure it has a valid FAT header */
 104         if (disk_read(0, 1, buffer) != 1) {
 105                 cur_dev = NULL;
 106                 return -1;
 107         }
 108
 109         /* Check if it's actually a DOS volume */
 110         if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
 111                 cur_dev = NULL;
 112                 return -1;
 113         }
 114
 115         /* Check for FAT12/FAT16/FAT32 filesystem */
 116         if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
 117                 return 0;
 118         if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
 119                 return 0;
 120
 121         cur_dev = NULL;
 122         return -1;
 123 }
 124
 125
 126 /*
 127  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 128  * Return index into string if found, -1 otherwise.
 129  */
 130 static int dirdelim(char *str)
 131 {
 132         char *start = str;
 133
 134         while (*str != '\0') {
 135                 if (ISDIRDELIM(*str))
 136                         return str - start;
 137                 str++;
 138         }
 139         return -1;
 140 }
 141
 142 /*
 143  * Extract zero terminated short name from a directory entry.
 144  */
 145 static void get_name(dir_entry *dirent, char *s_name)
 146 {
 147         char *ptr;
 148
 149         memcpy(s_name, dirent->name, 8);
 150         s_name[8] = '\0';
 151         ptr = s_name;
 152         while (*ptr && *ptr != ' ')
 153                 ptr++;
 154         if (dirent->ext[0] && dirent->ext[0] != ' ') {
 155                 *ptr = '.';
 156                 ptr++;
 157                 memcpy(ptr, dirent->ext, 3);
 158                 ptr[3] = '\0';
 159                 while (*ptr && *ptr != ' ')
 160                         ptr++;
 161         }
 162         *ptr = '\0';
 163         if (*s_name == DELETED_FLAG)
 164                 *s_name = '\0';
 165         else if (*s_name == aRING)
 166                 *s_name = DELETED_FLAG;
 167         downcase(s_name);
 168 }
 169
 170 /*
 171  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 172  * On failure 0x00 is returned.
 173  */
 174 static __u32 get_fatent(fsdata *mydata, __u32 entry)
 175 {
 176         __u32 bufnum;
 177         __u32 off16, offset;
 178         __u32 ret = 0x00;
 179         __u16 val1, val2;
 180
 181         switch (mydata->fatsize) {
 182         case 32:
 183                 bufnum = entry / FAT32BUFSIZE;
 184                 offset = entry - bufnum * FAT32BUFSIZE;
 185                 break;
 186         case 16:
 187                 bufnum = entry / FAT16BUFSIZE;
 188                 offset = entry - bufnum * FAT16BUFSIZE;
 189                 break;
 190         case 12:
 191                 bufnum = entry / FAT12BUFSIZE;
 192                 offset = entry - bufnum * FAT12BUFSIZE;
 193                 break;
 194
 195         default:
 196                 /* Unsupported FAT size */
 197                 return ret;
 198         }
 199
 200         debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
 201                mydata->fatsize, entry, entry, offset, offset);
 202
 203         /* Read a new block of FAT entries into the cache. */
 204         if (bufnum != mydata->fatbufnum) {
 205                 __u32 getsize = FATBUFBLOCKS;
 206                 __u8 *bufptr = mydata->fatbuf;
 207                 __u32 fatlength = mydata->fatlength;
 208                 __u32 startblock = bufnum * FATBUFBLOCKS;
 209
 210                 if (startblock + getsize > fatlength)
 211                         getsize = fatlength - startblock;
 212
 213                 startblock += mydata->fat_sect; /* Offset from start of disk */
 214
 215                 if (disk_read(startblock, getsize, bufptr) < 0) {
 216                         debug("Error reading FAT blocks\n");
 217                         return ret;
 218                 }
 219                 mydata->fatbufnum = bufnum;
 220         }
 221
 222         /* Get the actual entry from the table */
 223         switch (mydata->fatsize) {
 224         case 32:
 225                 ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
 226                 break;
 227         case 16:
 228                 ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
 229                 break;
 230         case 12:
 231                 off16 = (offset * 3) / 4;
 232
 233                 switch (offset & 0x3) {
 234                 case 0:
 235                         ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
 236                         ret &= 0xfff;
 237                         break;
 238                 case 1:
 239                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 240                         val1 &= 0xf000;
 241                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 242                         val2 &= 0x00ff;
 243                         ret = (val2 << 4) | (val1 >> 12);
 244                         break;
 245                 case 2:
 246                         val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 247                         val1 &= 0xff00;
 248                         val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
 249                         val2 &= 0x000f;
 250                         ret = (val2 << 8) | (val1 >> 8);
 251                         break;
 252                 case 3:
 253                         ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
 254                         ret = (ret & 0xfff0) >> 4;
 255                         break;
 256                 default:
 257                         break;
 258                 }
 259                 break;
 260         }
 261         debug("FAT%d: ret: %08x, offset: %04x\n",
 262                mydata->fatsize, ret, offset);
 263
 264         return ret;
 265 }
 266
 267 /*
 268  * Read at most 'size' bytes from the specified cluster into 'buffer'.
 269  * Return 0 on success, -1 otherwise.
 270  */
 271 static int
 272 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
 273 {
 274         __u32 idx = 0;
 275         __u32 startsect;
 276         int ret;
 277
 278         if (clustnum > 0) {
 279                 startsect = mydata->data_begin +
 280                                 clustnum * mydata->clust_size;
 281         } else {
 282                 startsect = mydata->rootdir_sect;
 283         }
 284
 285         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 286
 287         if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
 288                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 289
 290                 printf("FAT: Misaligned buffer address (%p)\n", buffer);
 291
 292                 while (size >= mydata->sect_size) {
 293                         ret = disk_read(startsect++, 1, tmpbuf);
 294                         if (ret != 1) {
 295                                 debug("Error reading data (got %d)\n", ret);
 296                                 return -1;
 297                         }
 298
 299                         memcpy(buffer, tmpbuf, mydata->sect_size);
 300                         buffer += mydata->sect_size;
 301                         size -= mydata->sect_size;
 302                 }
 303         } else {
 304                 idx = size / mydata->sect_size;
 305                 ret = disk_read(startsect, idx, buffer);
 306                 if (ret != idx) {
 307                         debug("Error reading data (got %d)\n", ret);
 308                         return -1;
 309                 }
 310                 startsect += idx;
 311                 idx *= mydata->sect_size;
 312                 buffer += idx;
 313                 size -= idx;
 314         }
 315         if (size) {
 316                 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
 317
 318                 ret = disk_read(startsect, 1, tmpbuf);
 319                 if (ret != 1) {
 320                         debug("Error reading data (got %d)\n", ret);
 321                         return -1;
 322                 }
 323
 324                 memcpy(buffer, tmpbuf, size);
 325         }
 326
 327         return 0;
 328 }
 329
 330 /*
 331  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
 332  * into 'buffer'.
 333  * Return the number of bytes read or -1 on fatal errors.
 334  */
 335 static long
 336 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
 337              unsigned long maxsize)
 338 {
 339         unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
 340         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 341         __u32 curclust = START(dentptr);
 342         __u32 endclust, newclust;
 343         unsigned long actsize;
 344
 345         debug("Filesize: %ld bytes\n", filesize);
 346
 347         if (maxsize > 0 && filesize > maxsize)
 348                 filesize = maxsize;
 349
 350         debug("%ld bytes\n", filesize);
 351
 352         actsize = bytesperclust;
 353         endclust = curclust;
 354
 355         do {
 356                 /* search for consecutive clusters */
 357                 while (actsize < filesize) {
 358                         newclust = get_fatent(mydata, endclust);
 359                         if ((newclust - 1) != endclust)
 360                                 goto getit;
 361                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 362                                 debug("curclust: 0x%x\n", newclust);
 363                                 debug("Invalid FAT entry\n");
 364                                 return gotsize;
 365                         }
 366                         endclust = newclust;
 367                         actsize += bytesperclust;
 368                 }
 369
 370                 /* get remaining bytes */
 371                 actsize = filesize;
 372                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 373                         printf("Error reading cluster\n");
 374                         return -1;
 375                 }
 376                 gotsize += actsize;
 377                 return gotsize;
 378 getit:
 379                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 380                         printf("Error reading cluster\n");
 381                         return -1;
 382                 }
 383                 gotsize += (int)actsize;
 384                 filesize -= actsize;
 385                 buffer += actsize;
 386
 387                 curclust = get_fatent(mydata, endclust);
 388                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 389                         debug("curclust: 0x%x\n", curclust);
 390                         printf("Invalid FAT entry\n");
 391                         return gotsize;
 392                 }
 393                 actsize = bytesperclust;
 394                 endclust = curclust;
 395         } while (1);
 396 }
 397
 398 #ifdef CONFIG_SUPPORT_VFAT
 399 /*
 400  * Extract the file name information from 'slotptr' into 'l_name',
 401  * starting at l_name[*idx].
 402  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 403  */
 404 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
 405 {
 406         int j;
 407
 408         for (j = 0; j <= 8; j += 2) {
 409                 l_name[*idx] = slotptr->name0_4[j];
 410                 if (l_name[*idx] == 0x00)
 411                         return 1;
 412                 (*idx)++;
 413         }
 414         for (j = 0; j <= 10; j += 2) {
 415                 l_name[*idx] = slotptr->name5_10[j];
 416                 if (l_name[*idx] == 0x00)
 417                         return 1;
 418                 (*idx)++;
 419         }
 420         for (j = 0; j <= 2; j += 2) {
 421                 l_name[*idx] = slotptr->name11_12[j];
 422                 if (l_name[*idx] == 0x00)
 423                         return 1;
 424                 (*idx)++;
 425         }
 426
 427         return 0;
 428 }
 429
 430 /*
 431  * Extract the full long filename starting at 'retdent' (which is really
 432  * a slot) into 'l_name'. If successful also copy the real directory entry
 433  * into 'retdent'
 434  * Return 0 on success, -1 otherwise.
 435  */
 436 __u8 get_vfatname_block[MAX_CLUSTSIZE]
 437         __aligned(ARCH_DMA_MINALIGN);
 438
 439 static int
 440 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
 441              dir_entry *retdent, char *l_name)
 442 {
 443         dir_entry *realdent;
 444         dir_slot *slotptr = (dir_slot *)retdent;
 445         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 446                                                         PREFETCH_BLOCKS :
 447                                                         mydata->clust_size);
 448         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 449         int idx = 0;
 450
 451         if (counter > VFAT_MAXSEQ) {
 452                 debug("Error: VFAT name is too long\n");
 453                 return -1;
 454         }
 455
 456         while ((__u8 *)slotptr < buflimit) {
 457                 if (counter == 0)
 458                         break;
 459                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 460                         return -1;
 461                 slotptr++;
 462                 counter--;
 463         }
 464
 465         if ((__u8 *)slotptr >= buflimit) {
 466                 dir_slot *slotptr2;
 467
 468                 if (curclust == 0)
 469                         return -1;
 470                 curclust = get_fatent(mydata, curclust);
 471                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 472                         debug("curclust: 0x%x\n", curclust);
 473                         printf("Invalid FAT entry\n");
 474                         return -1;
 475                 }
 476
 477                 if (get_cluster(mydata, curclust, get_vfatname_block,
 478                                 mydata->clust_size * mydata->sect_size) != 0) {
 479                         debug("Error: reading directory block\n");
 480                         return -1;
 481                 }
 482
 483                 slotptr2 = (dir_slot *)get_vfatname_block;
 484                 while (counter > 0) {
 485                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 486                             & 0xff) != counter)
 487                                 return -1;
 488                         slotptr2++;
 489                         counter--;
 490                 }
 491
 492                 /* Save the real directory entry */
 493                 realdent = (dir_entry *)slotptr2;
 494                 while ((__u8 *)slotptr2 > get_vfatname_block) {
 495                         slotptr2--;
 496                         slot2str(slotptr2, l_name, &idx);
 497                 }
 498         } else {
 499                 /* Save the real directory entry */
 500                 realdent = (dir_entry *)slotptr;
 501         }
 502
 503         do {
 504                 slotptr--;
 505                 if (slot2str(slotptr, l_name, &idx))
 506                         break;
 507         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 508
 509         l_name[idx] = '\0';
 510         if (*l_name == DELETED_FLAG)
 511                 *l_name = '\0';
 512         else if (*l_name == aRING)
 513                 *l_name = DELETED_FLAG;
 514         downcase(l_name);
 515
 516         /* Return the real directory entry */
 517         memcpy(retdent, realdent, sizeof(dir_entry));
 518
 519         return 0;
 520 }
 521
 522 /* Calculate short name checksum */
 523 static __u8 mkcksum(const char *str)
 524 {
 525         int i;
 526
 527         __u8 ret = 0;
 528
 529         for (i = 0; i < 11; i++) {
 530                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + str[i];
 531         }
 532
 533         return ret;
 534 }
 535 #endif  /* CONFIG_SUPPORT_VFAT */
 536
 537 /*
 538  * Get the directory entry associated with 'filename' from the directory
 539  * starting at 'startsect'
 540  */
 541 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
 542         __aligned(ARCH_DMA_MINALIGN);
 543
 544 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
 545                                   char *filename, dir_entry *retdent,
 546                                   int dols)
 547 {
 548         __u16 prevcksum = 0xffff;
 549         __u32 curclust = START(retdent);
 550         int files = 0, dirs = 0;
 551
 552         debug("get_dentfromdir: %s\n", filename);
 553
 554         while (1) {
 555                 dir_entry *dentptr;
 556
 557                 int i;
 558
 559                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 560                                 mydata->clust_size * mydata->sect_size) != 0) {
 561                         debug("Error: reading directory block\n");
 562                         return NULL;
 563                 }
 564
 565                 dentptr = (dir_entry *)get_dentfromdir_block;
 566
 567                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 568                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 569
 570                         l_name[0] = '\0';
 571                         if (dentptr->name[0] == DELETED_FLAG) {
 572                                 dentptr++;
 573                                 continue;
 574                         }
 575                         if ((dentptr->attr & ATTR_VOLUME)) {
 576 #ifdef CONFIG_SUPPORT_VFAT
 577                                 if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 578                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 579                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 580                                         get_vfatname(mydata, curclust,
 581                                                      get_dentfromdir_block,
 582                                                      dentptr, l_name);
 583                                         if (dols) {
 584                                                 int isdir;
 585                                                 char dirc;
 586                                                 int doit = 0;
 587
 588                                                 isdir = (dentptr->attr & ATTR_DIR);
 589
 590                                                 if (isdir) {
 591                                                         dirs++;
 592                                                         dirc = '/';
 593                                                         doit = 1;
 594                                                 } else {
 595                                                         dirc = ' ';
 596                                                         if (l_name[0] != 0) {
 597                                                                 files++;
 598                                                                 doit = 1;
 599                                                         }
 600                                                 }
 601                                                 if (doit) {
 602                                                         if (dirc == ' ') {
 603                                                                 printf(" %8ld   %s%c\n",
 604                                                                         (long)FAT2CPU32(dentptr->size),
 605                                                                         l_name,
 606                                                                         dirc);
 607                                                         } else {
 608                                                                 printf("            %s%c\n",
 609                                                                         l_name,
 610                                                                         dirc);
 611                                                         }
 612                                                 }
 613                                                 dentptr++;
 614                                                 continue;
 615                                         }
 616                                         debug("vfatname: |%s|\n", l_name);
 617                                 } else
 618 #endif
 619                                 {
 620                                         /* Volume label or VFAT entry */
 621                                         dentptr++;
 622                                         continue;
 623                                 }
 624                         }
 625                         if (dentptr->name[0] == 0) {
 626                                 if (dols) {
 627                                         printf("\n%d file(s), %d dir(s)\n\n",
 628                                                 files, dirs);
 629                                 }
 630                                 debug("Dentname == NULL - %d\n", i);
 631                                 return NULL;
 632                         }
 633 #ifdef CONFIG_SUPPORT_VFAT
 634                         if (dols && mkcksum(dentptr->name) == prevcksum) {
 635                                 prevcksum = 0xffff;
 636                                 dentptr++;
 637                                 continue;
 638                         }
 639 #endif
 640                         get_name(dentptr, s_name);
 641                         if (dols) {
 642                                 int isdir = (dentptr->attr & ATTR_DIR);
 643                                 char dirc;
 644                                 int doit = 0;
 645
 646                                 if (isdir) {
 647                                         dirs++;
 648                                         dirc = '/';
 649                                         doit = 1;
 650                                 } else {
 651                                         dirc = ' ';
 652                                         if (s_name[0] != 0) {
 653                                                 files++;
 654                                                 doit = 1;
 655                                         }
 656                                 }
 657
 658                                 if (doit) {
 659                                         if (dirc == ' ') {
 660                                                 printf(" %8ld   %s%c\n",
 661                                                         (long)FAT2CPU32(dentptr->size),
 662                                                         s_name, dirc);
 663                                         } else {
 664                                                 printf("            %s%c\n",
 665                                                         s_name, dirc);
 666                                         }
 667                                 }
 668
 669                                 dentptr++;
 670                                 continue;
 671                         }
 672
 673                         if (strcmp(filename, s_name)
 674                             && strcmp(filename, l_name)) {
 675                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 676                                 dentptr++;
 677                                 continue;
 678                         }
 679
 680                         memcpy(retdent, dentptr, sizeof(dir_entry));
 681
 682                         debug("DentName: %s", s_name);
 683                         debug(", start: 0x%x", START(dentptr));
 684                         debug(", size:  0x%x %s\n",
 685                               FAT2CPU32(dentptr->size),
 686                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 687
 688                         return retdent;
 689                 }
 690
 691                 curclust = get_fatent(mydata, curclust);
 692                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 693                         debug("curclust: 0x%x\n", curclust);
 694                         printf("Invalid FAT entry\n");
 695                         return NULL;
 696                 }
 697         }
 698
 699         return NULL;
 700 }
 701
 702 /*
 703  * Read boot sector and volume info from a FAT filesystem
 704  */
 705 static int
 706 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
 707 {
 708         __u8 *block;
 709         volume_info *vistart;
 710         int ret = 0;
 711
 712         if (cur_dev == NULL) {
 713                 debug("Error: no device selected\n");
 714                 return -1;
 715         }
 716
 717         block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
 718         if (block == NULL) {
 719                 debug("Error: allocating block\n");
 720                 return -1;
 721         }
 722
 723         if (disk_read(0, 1, block) < 0) {
 724                 debug("Error: reading block\n");
 725                 goto fail;
 726         }
 727
 728         memcpy(bs, block, sizeof(boot_sector));
 729         bs->reserved = FAT2CPU16(bs->reserved);
 730         bs->fat_length = FAT2CPU16(bs->fat_length);
 731         bs->secs_track = FAT2CPU16(bs->secs_track);
 732         bs->heads = FAT2CPU16(bs->heads);
 733         bs->total_sect = FAT2CPU32(bs->total_sect);
 734
 735         /* FAT32 entries */
 736         if (bs->fat_length == 0) {
 737                 /* Assume FAT32 */
 738                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 739                 bs->flags = FAT2CPU16(bs->flags);
 740                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 741                 bs->info_sector = FAT2CPU16(bs->info_sector);
 742                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 743                 vistart = (volume_info *)(block + sizeof(boot_sector));
 744                 *fatsize = 32;
 745         } else {
 746                 vistart = (volume_info *)&(bs->fat32_length);
 747                 *fatsize = 0;
 748         }
 749         memcpy(volinfo, vistart, sizeof(volume_info));
 750
 751         if (*fatsize == 32) {
 752                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 753                         goto exit;
 754         } else {
 755                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 756                         *fatsize = 12;
 757                         goto exit;
 758                 }
 759                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 760                         *fatsize = 16;
 761                         goto exit;
 762                 }
 763         }
 764
 765         debug("Error: broken fs_type sign\n");
 766 fail:
 767         ret = -1;
 768 exit:
 769         free(block);
 770         return ret;
 771 }
 772
 773 __u8 do_fat_read_block[MAX_CLUSTSIZE]
 774         __aligned(ARCH_DMA_MINALIGN);
 775
 776 long
 777 do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
 778 {
 779         char fnamecopy[2048];
 780         boot_sector bs;
 781         volume_info volinfo;
 782         fsdata datablock;
 783         fsdata *mydata = &datablock;
 784         dir_entry *dentptr = NULL;
 785         __u16 prevcksum = 0xffff;
 786         char *subname = "";
 787         __u32 cursect;
 788         int idx, isdir = 0;
 789         int files = 0, dirs = 0;
 790         long ret = -1;
 791         int firsttime;
 792         __u32 root_cluster = 0;
 793         int rootdir_size = 0;
 794         int j;
 795
 796         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 797                 debug("Error: reading boot sector\n");
 798                 return -1;
 799         }
 800
 801         if (mydata->fatsize == 32) {
 802                 root_cluster = bs.root_cluster;
 803                 mydata->fatlength = bs.fat32_length;
 804         } else {
 805                 mydata->fatlength = bs.fat_length;
 806         }
 807
 808         mydata->fat_sect = bs.reserved;
 809
 810         cursect = mydata->rootdir_sect
 811                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 812
 813         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 814         mydata->clust_size = bs.cluster_size;
 815         if (mydata->sect_size != cur_part_info.blksz) {
 816                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 817                                 mydata->sect_size, cur_part_info.blksz);
 818                 return -1;
 819         }
 820
 821         if (mydata->fatsize == 32) {
 822                 mydata->data_begin = mydata->rootdir_sect -
 823                                         (mydata->clust_size * 2);
 824         } else {
 825                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 826                                  bs.dir_entries[0]) *
 827                                  sizeof(dir_entry)) /
 828                                  mydata->sect_size;
 829                 mydata->data_begin = mydata->rootdir_sect +
 830                                         rootdir_size -
 831                                         (mydata->clust_size * 2);
 832         }
 833
 834         mydata->fatbufnum = -1;
 835         mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
 836         if (mydata->fatbuf == NULL) {
 837                 debug("Error: allocating memory\n");
 838                 return -1;
 839         }
 840
 841 #ifdef CONFIG_SUPPORT_VFAT
 842         debug("VFAT Support enabled\n");
 843 #endif
 844         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 845                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 846         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 847                "Data begins at: %d\n",
 848                root_cluster,
 849                mydata->rootdir_sect,
 850                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 851         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 852               mydata->clust_size);
 853
 854         /* "cwd" is always the root... */
 855         while (ISDIRDELIM(*filename))
 856                 filename++;
 857
 858         /* Make a copy of the filename and convert it to lowercase */
 859         strcpy(fnamecopy, filename);
 860         downcase(fnamecopy);
 861
 862         if (*fnamecopy == '\0') {
 863                 if (!dols)
 864                         goto exit;
 865
 866                 dols = LS_ROOT;
 867         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 868                 isdir = 1;
 869                 fnamecopy[idx] = '\0';
 870                 subname = fnamecopy + idx + 1;
 871
 872                 /* Handle multiple delimiters */
 873                 while (ISDIRDELIM(*subname))
 874                         subname++;
 875         } else if (dols) {
 876                 isdir = 1;
 877         }
 878
 879         j = 0;
 880         while (1) {
 881                 int i;
 882
 883                 if (j == 0) {
 884                         debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 885                                 cursect, mydata->clust_size, DIRENTSPERBLOCK);
 886
 887                         if (disk_read(cursect,
 888                                         (mydata->fatsize == 32) ?
 889                                         (mydata->clust_size) :
 890                                         PREFETCH_BLOCKS,
 891                                         do_fat_read_block) < 0) {
 892                                 debug("Error: reading rootdir block\n");
 893                                 goto exit;
 894                         }
 895
 896                         dentptr = (dir_entry *) do_fat_read_block;
 897                 }
 898
 899                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 900                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 901
 902                         l_name[0] = '\0';
 903                         if (dentptr->name[0] == DELETED_FLAG) {
 904                                 dentptr++;
 905                                 continue;
 906                         }
 907                         if ((dentptr->attr & ATTR_VOLUME)) {
 908 #ifdef CONFIG_SUPPORT_VFAT
 909                                 if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 910                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 911                                         prevcksum =
 912                                                 ((dir_slot *)dentptr)->alias_checksum;
 913
 914                                         get_vfatname(mydata,
 915                                                      root_cluster,
 916                                                      do_fat_read_block,
 917                                                      dentptr, l_name);
 918
 919                                         if (dols == LS_ROOT) {
 920                                                 char dirc;
 921                                                 int doit = 0;
 922                                                 int isdir =
 923                                                         (dentptr->attr & ATTR_DIR);
 924
 925                                                 if (isdir) {
 926                                                         dirs++;
 927                                                         dirc = '/';
 928                                                         doit = 1;
 929                                                 } else {
 930                                                         dirc = ' ';
 931                                                         if (l_name[0] != 0) {
 932                                                                 files++;
 933                                                                 doit = 1;
 934                                                         }
 935                                                 }
 936                                                 if (doit) {
 937                                                         if (dirc == ' ') {
 938                                                                 printf(" %8ld   %s%c\n",
 939                                                                         (long)FAT2CPU32(dentptr->size),
 940                                                                         l_name,
 941                                                                         dirc);
 942                                                         } else {
 943                                                                 printf("            %s%c\n",
 944                                                                         l_name,
 945                                                                         dirc);
 946                                                         }
 947                                                 }
 948                                                 dentptr++;
 949                                                 continue;
 950                                         }
 951                                         debug("Rootvfatname: |%s|\n",
 952                                                l_name);
 953                                 } else
 954 #endif
 955                                 {
 956                                         /* Volume label or VFAT entry */
 957                                         dentptr++;
 958                                         continue;
 959                                 }
 960                         } else if (dentptr->name[0] == 0) {
 961                                 debug("RootDentname == NULL - %d\n", i);
 962                                 if (dols == LS_ROOT) {
 963                                         printf("\n%d file(s), %d dir(s)\n\n",
 964                                                 files, dirs);
 965                                         ret = 0;
 966                                 }
 967                                 goto exit;
 968                         }
 969 #ifdef CONFIG_SUPPORT_VFAT
 970                         else if (dols == LS_ROOT &&
 971                                  mkcksum(dentptr->name) == prevcksum) {
 972                                 prevcksum = 0xffff;
 973                                 dentptr++;
 974                                 continue;
 975                         }
 976 #endif
 977                         get_name(dentptr, s_name);
 978
 979                         if (dols == LS_ROOT) {
 980                                 int isdir = (dentptr->attr & ATTR_DIR);
 981                                 char dirc;
 982                                 int doit = 0;
 983
 984                                 if (isdir) {
 985                                         dirc = '/';
 986                                         if (s_name[0] != 0) {
 987                                                 dirs++;
 988                                                 doit = 1;
 989                                         }
 990                                 } else {
 991                                         dirc = ' ';
 992                                         if (s_name[0] != 0) {
 993                                                 files++;
 994                                                 doit = 1;
 995                                         }
 996                                 }
 997                                 if (doit) {
 998                                         if (dirc == ' ') {
 999                                                 printf(" %8ld   %s%c\n",
1000                                                         (long)FAT2CPU32(dentptr->size),
1001                                                         s_name, dirc);
1002                                         } else {
1003                                                 printf("            %s%c\n",
1004                                                         s_name, dirc);
1005                                         }
1006                                 }
1007                                 dentptr++;
1008                                 continue;
1009                         }
1010
1011                         if (strcmp(fnamecopy, s_name)
1012                             && strcmp(fnamecopy, l_name)) {
1013                                 debug("RootMismatch: |%s|%s|\n", s_name,
1014                                        l_name);
1015                                 dentptr++;
1016                                 continue;
1017                         }
1018
1019                         if (isdir && !(dentptr->attr & ATTR_DIR))
1020                                 goto exit;
1021
1022                         debug("RootName: %s", s_name);
1023                         debug(", start: 0x%x", START(dentptr));
1024                         debug(", size:  0x%x %s\n",
1025                                FAT2CPU32(dentptr->size),
1026                                isdir ? "(DIR)" : "");
1027
1028                         goto rootdir_done;      /* We got a match */
1029                 }
1030                 debug("END LOOP: j=%d   clust_size=%d\n", j,
1031                        mydata->clust_size);
1032
1033                 /*
1034                  * On FAT32 we must fetch the FAT entries for the next
1035                  * root directory clusters when a cluster has been
1036                  * completely processed.
1037                  */
1038                 ++j;
1039                 int rootdir_end = 0;
1040                 if (mydata->fatsize == 32) {
1041                         if (j == mydata->clust_size) {
1042                                 int nxtsect = 0;
1043                                 int nxt_clust = 0;
1044
1045                                 nxt_clust = get_fatent(mydata, root_cluster);
1046                                 rootdir_end = CHECK_CLUST(nxt_clust, 32);
1047
1048                                 nxtsect = mydata->data_begin +
1049                                         (nxt_clust * mydata->clust_size);
1050
1051                                 root_cluster = nxt_clust;
1052
1053                                 cursect = nxtsect;
1054                                 j = 0;
1055                         }
1056                 } else {
1057                         if (j == PREFETCH_BLOCKS)
1058                                 j = 0;
1059
1060                         rootdir_end = (++cursect - mydata->rootdir_sect >=
1061                                        rootdir_size);
1062                 }
1063
1064                 /* If end of rootdir reached */
1065                 if (rootdir_end) {
1066                         if (dols == LS_ROOT) {
1067                                 printf("\n%d file(s), %d dir(s)\n\n",
1068                                        files, dirs);
1069                                 ret = 0;
1070                         }
1071                         goto exit;
1072                 }
1073         }
1074 rootdir_done:
1075
1076         firsttime = 1;
1077
1078         while (isdir) {
1079                 int startsect = mydata->data_begin
1080                         + START(dentptr) * mydata->clust_size;
1081                 dir_entry dent;
1082                 char *nextname = NULL;
1083
1084                 dent = *dentptr;
1085                 dentptr = &dent;
1086
1087                 idx = dirdelim(subname);
1088
1089                 if (idx >= 0) {
1090                         subname[idx] = '\0';
1091                         nextname = subname + idx + 1;
1092                         /* Handle multiple delimiters */
1093                         while (ISDIRDELIM(*nextname))
1094                                 nextname++;
1095                         if (dols && *nextname == '\0')
1096                                 firsttime = 0;
1097                 } else {
1098                         if (dols && firsttime) {
1099                                 firsttime = 0;
1100                         } else {
1101                                 isdir = 0;
1102                         }
1103                 }
1104
1105                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1106                                      isdir ? 0 : dols) == NULL) {
1107                         if (dols && !isdir)
1108                                 ret = 0;
1109                         goto exit;
1110                 }
1111
1112                 if (isdir && !(dentptr->attr & ATTR_DIR))
1113                         goto exit;
1114
1115                 if (idx >= 0)
1116                         subname = nextname;
1117         }
1118
1119         ret = get_contents(mydata, dentptr, buffer, maxsize);
1120         debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1121
1122 exit:
1123         free(mydata->fatbuf);
1124         return ret;
1125 }
1126
1127 int file_fat_detectfs(void)
1128 {
1129         boot_sector bs;
1130         volume_info volinfo;
1131         int fatsize;
1132         char vol_label[12];
1133
1134         if (cur_dev == NULL) {
1135                 printf("No current device\n");
1136                 return 1;
1137         }
1138
1139 #if defined(CONFIG_CMD_IDE) || \
1140     defined(CONFIG_CMD_SATA) || \
1141     defined(CONFIG_CMD_SCSI) || \
1142     defined(CONFIG_CMD_USB) || \
1143     defined(CONFIG_MMC)
1144         printf("Interface:  ");
1145         switch (cur_dev->if_type) {
1146         case IF_TYPE_IDE:
1147                 printf("IDE");
1148                 break;
1149         case IF_TYPE_SATA:
1150                 printf("SATA");
1151                 break;
1152         case IF_TYPE_SCSI:
1153                 printf("SCSI");
1154                 break;
1155         case IF_TYPE_ATAPI:
1156                 printf("ATAPI");
1157                 break;
1158         case IF_TYPE_USB:
1159                 printf("USB");
1160                 break;
1161         case IF_TYPE_DOC:
1162                 printf("DOC");
1163                 break;
1164         case IF_TYPE_MMC:
1165                 printf("MMC");
1166                 break;
1167         default:
1168                 printf("Unknown");
1169         }
1170
1171         printf("\n  Device %d: ", cur_dev->dev);
1172         dev_print(cur_dev);
1173 #endif
1174
1175         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1176                 printf("\nNo valid FAT fs found\n");
1177                 return 1;
1178         }
1179
1180         memcpy(vol_label, volinfo.volume_label, 11);
1181         vol_label[11] = '\0';
1182         volinfo.fs_type[5] = '\0';
1183
1184         printf("Partition %d: Filesystem: %s \"%s\"\n", cur_part_nr,
1185                 volinfo.fs_type, vol_label);
1186
1187         return 0;
1188 }
1189
1190 int file_fat_ls(const char *dir)
1191 {
1192         return do_fat_read(dir, NULL, 0, LS_YES);
1193 }
1194
1195 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1196 {
1197         printf("reading %s\n", filename);
1198         return do_fat_read(filename, buffer, maxsize, LS_NO);
1199 }