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
  35 /*
  36  * Convert a string to lowercase.
  37  */
  38 static void downcase (char *str)
  39 {
  40         while (*str != '\0') {
  41                 TOLOWER(*str);
  42                 str++;
  43         }
  44 }
  45
  46 static block_dev_desc_t *cur_dev;
  47 static unsigned int cur_part_nr;
  48 static disk_partition_t cur_part_info;
  49
  50 #define DOS_BOOT_MAGIC_OFFSET   0x1fe
  51 #define DOS_FS_TYPE_OFFSET      0x36
  52 #define DOS_FS32_TYPE_OFFSET    0x52
  53
  54 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
  55 {
  56         if (!cur_dev || !cur_dev->block_read)
  57                 return -1;
  58
  59         return cur_dev->block_read(cur_dev->dev,
  60                         cur_part_info.start + block, nr_blocks, buf);
  61 }
  62
  63 int fat_register_device (block_dev_desc_t * dev_desc, int part_no)
  64 {
  65         unsigned char buffer[dev_desc->blksz];
  66
  67         /* First close any currently found FAT filesystem */
  68         cur_dev = NULL;
  69
  70 #if (defined(CONFIG_CMD_IDE) || \
  71      defined(CONFIG_CMD_MG_DISK) || \
  72      defined(CONFIG_CMD_SATA) || \
  73      defined(CONFIG_CMD_SCSI) || \
  74      defined(CONFIG_CMD_USB) || \
  75      defined(CONFIG_MMC) || \
  76      defined(CONFIG_SYSTEMACE) )
  77
  78         /* Read the partition table, if present */
  79         if (!get_partition_info(dev_desc, part_no, &cur_part_info)) {
  80                 cur_dev = dev_desc;
  81                 cur_part_nr = part_no;
  82         }
  83 #endif
  84
  85         /* Otherwise it might be a superfloppy (whole-disk FAT filesystem) */
  86         if (!cur_dev) {
  87                 if (part_no != 1) {
  88                         printf("** Partition %d not valid on device %d **\n",
  89                                         part_no, dev_desc->dev);
  90                         return -1;
  91                 }
  92
  93                 cur_dev = dev_desc;
  94                 cur_part_nr = 1;
  95                 cur_part_info.start = 0;
  96                 cur_part_info.size = dev_desc->lba;
  97                 cur_part_info.blksz = dev_desc->blksz;
  98                 memset(cur_part_info.name, 0, sizeof(cur_part_info.name));
  99                 memset(cur_part_info.type, 0, sizeof(cur_part_info.type));
 100         }
 101
 102         /* Make sure it has a valid FAT header */
 103         if (disk_read(0, 1, buffer) != 1) {
 104                 cur_dev = NULL;
 105                 return -1;
 106         }
 107
 108         /* Check if it's actually a DOS volume */
 109         if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
 110                 cur_dev = NULL;
 111                 return -1;
 112         }
 113
 114         /* Check for FAT12/FAT16/FAT32 filesystem */
 115         if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
 116                 return 0;
 117         if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
 118                 return 0;
 119
 120         cur_dev = NULL;
 121         return -1;
 122 }
 123
 124
 125 /*
 126  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 127  * Return index into string if found, -1 otherwise.
 128  */
 129 static int dirdelim (char *str)
 130 {
 131         char *start = str;
 132
 133         while (*str != '\0') {
 134                 if (ISDIRDELIM(*str))
 135                         return str - start;
 136                 str++;
 137         }
 138         return -1;
 139 }
 140
 141 /*
 142  * Extract zero terminated short name from a directory entry.
 143  */
 144 static void get_name (dir_entry *dirent, char *s_name)
 145 {
 146         char *ptr;
 147
 148         memcpy(s_name, dirent->name, 8);
 149         s_name[8] = '\0';
 150         ptr = s_name;
 151         while (*ptr && *ptr != ' ')
 152                 ptr++;
 153         if (dirent->ext[0] && dirent->ext[0] != ' ') {
 154                 *ptr = '.';
 155                 ptr++;
 156                 memcpy(ptr, dirent->ext, 3);
 157                 ptr[3] = '\0';
 158                 while (*ptr && *ptr != ' ')
 159                         ptr++;
 160         }
 161         *ptr = '\0';
 162         if (*s_name == DELETED_FLAG)
 163                 *s_name = '\0';
 164         else if (*s_name == aRING)
 165                 *s_name = DELETED_FLAG;
 166         downcase(s_name);
 167 }
 168
 169 /*
 170  * Get the entry at index 'entry' in a FAT (12/16/32) table.
 171  * On failure 0x00 is returned.
 172  */
 173 static __u32 get_fatent (fsdata *mydata, __u32 entry)
 174 {
 175         __u32 bufnum;
 176         __u32 off16, offset;
 177         __u32 ret = 0x00;
 178         __u16 val1, val2;
 179
 180         switch (mydata->fatsize) {
 181         case 32:
 182                 bufnum = entry / FAT32BUFSIZE;
 183                 offset = entry - bufnum * FAT32BUFSIZE;
 184                 break;
 185         case 16:
 186                 bufnum = entry / FAT16BUFSIZE;
 187                 offset = entry - bufnum * FAT16BUFSIZE;
 188                 break;
 189         case 12:
 190                 bufnum = entry / FAT12BUFSIZE;
 191                 offset = entry - bufnum * FAT12BUFSIZE;
 192                 break;
 193
 194         default:
 195                 /* Unsupported FAT size */
 196                 return ret;
 197         }
 198
 199         debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
 200                mydata->fatsize, entry, entry, offset, offset);
 201
 202         /* Read a new block of FAT entries into the cache. */
 203         if (bufnum != mydata->fatbufnum) {
 204                 __u32 getsize = FATBUFBLOCKS;
 205                 __u8 *bufptr = mydata->fatbuf;
 206                 __u32 fatlength = mydata->fatlength;
 207                 __u32 startblock = bufnum * FATBUFBLOCKS;
 208
 209                 if (getsize > fatlength)
 210                         getsize = fatlength;
 211
 212                 fatlength *= mydata->sect_size; /* We want it in bytes now */
 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,
 273              unsigned long size)
 274 {
 275         __u32 idx = 0;
 276         __u32 startsect;
 277         __u32 nr_sect;
 278         int ret;
 279
 280         if (clustnum > 0) {
 281                 startsect = mydata->data_begin +
 282                                 clustnum * mydata->clust_size;
 283         } else {
 284                 startsect = mydata->rootdir_sect;
 285         }
 286
 287         debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
 288
 289         nr_sect = size / mydata->sect_size;
 290         ret = disk_read(startsect, nr_sect, buffer);
 291         if (ret != nr_sect) {
 292                 debug("Error reading data (got %d)\n", ret);
 293                 return -1;
 294         }
 295         if (size % mydata->sect_size) {
 296                 __u8 tmpbuf[mydata->sect_size];
 297
 298                 idx = size / mydata->sect_size;
 299                 ret = disk_read(startsect + idx, 1, tmpbuf);
 300                 if (ret != 1) {
 301                         debug("Error reading data (got %d)\n", ret);
 302                         return -1;
 303                 }
 304                 buffer += idx * mydata->sect_size;
 305
 306                 memcpy(buffer, tmpbuf, size % mydata->sect_size);
 307                 return 0;
 308         }
 309
 310         return 0;
 311 }
 312
 313 /*
 314  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
 315  * into 'buffer'.
 316  * Return the number of bytes read or -1 on fatal errors.
 317  */
 318 static long
 319 get_contents (fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
 320               unsigned long maxsize)
 321 {
 322         unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
 323         unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
 324         __u32 curclust = START(dentptr);
 325         __u32 endclust, newclust;
 326         unsigned long actsize;
 327
 328         debug("Filesize: %ld bytes\n", filesize);
 329
 330         if (maxsize > 0 && filesize > maxsize)
 331                 filesize = maxsize;
 332
 333         debug("%ld bytes\n", filesize);
 334
 335         actsize = bytesperclust;
 336         endclust = curclust;
 337
 338         do {
 339                 /* search for consecutive clusters */
 340                 while (actsize < filesize) {
 341                         newclust = get_fatent(mydata, endclust);
 342                         if ((newclust - 1) != endclust)
 343                                 goto getit;
 344                         if (CHECK_CLUST(newclust, mydata->fatsize)) {
 345                                 debug("curclust: 0x%x\n", newclust);
 346                                 debug("Invalid FAT entry\n");
 347                                 return gotsize;
 348                         }
 349                         endclust = newclust;
 350                         actsize += bytesperclust;
 351                 }
 352
 353                 /* actsize >= file size */
 354                 actsize -= bytesperclust;
 355
 356                 /* get remaining clusters */
 357                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 358                         printf("Error reading cluster\n");
 359                         return -1;
 360                 }
 361
 362                 /* get remaining bytes */
 363                 gotsize += (int)actsize;
 364                 filesize -= actsize;
 365                 buffer += actsize;
 366                 actsize = filesize;
 367                 if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
 368                         printf("Error reading cluster\n");
 369                         return -1;
 370                 }
 371                 gotsize += actsize;
 372                 return gotsize;
 373 getit:
 374                 if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
 375                         printf("Error reading cluster\n");
 376                         return -1;
 377                 }
 378                 gotsize += (int)actsize;
 379                 filesize -= actsize;
 380                 buffer += actsize;
 381
 382                 curclust = get_fatent(mydata, endclust);
 383                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 384                         debug("curclust: 0x%x\n", curclust);
 385                         printf("Invalid FAT entry\n");
 386                         return gotsize;
 387                 }
 388                 actsize = bytesperclust;
 389                 endclust = curclust;
 390         } while (1);
 391 }
 392
 393 #ifdef CONFIG_SUPPORT_VFAT
 394 /*
 395  * Extract the file name information from 'slotptr' into 'l_name',
 396  * starting at l_name[*idx].
 397  * Return 1 if terminator (zero byte) is found, 0 otherwise.
 398  */
 399 static int slot2str (dir_slot *slotptr, char *l_name, int *idx)
 400 {
 401         int j;
 402
 403         for (j = 0; j <= 8; j += 2) {
 404                 l_name[*idx] = slotptr->name0_4[j];
 405                 if (l_name[*idx] == 0x00)
 406                         return 1;
 407                 (*idx)++;
 408         }
 409         for (j = 0; j <= 10; j += 2) {
 410                 l_name[*idx] = slotptr->name5_10[j];
 411                 if (l_name[*idx] == 0x00)
 412                         return 1;
 413                 (*idx)++;
 414         }
 415         for (j = 0; j <= 2; j += 2) {
 416                 l_name[*idx] = slotptr->name11_12[j];
 417                 if (l_name[*idx] == 0x00)
 418                         return 1;
 419                 (*idx)++;
 420         }
 421
 422         return 0;
 423 }
 424
 425 /*
 426  * Extract the full long filename starting at 'retdent' (which is really
 427  * a slot) into 'l_name'. If successful also copy the real directory entry
 428  * into 'retdent'
 429  * Return 0 on success, -1 otherwise.
 430  */
 431 __attribute__ ((__aligned__ (__alignof__ (dir_entry))))
 432 __u8 get_vfatname_block[MAX_CLUSTSIZE];
 433
 434 static int
 435 get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
 436               dir_entry *retdent, char *l_name)
 437 {
 438         dir_entry *realdent;
 439         dir_slot *slotptr = (dir_slot *)retdent;
 440         __u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
 441                                                         PREFETCH_BLOCKS :
 442                                                         mydata->clust_size);
 443         __u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
 444         int idx = 0;
 445
 446         if (counter > VFAT_MAXSEQ) {
 447                 debug("Error: VFAT name is too long\n");
 448                 return -1;
 449         }
 450
 451         while ((__u8 *)slotptr < buflimit) {
 452                 if (counter == 0)
 453                         break;
 454                 if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
 455                         return -1;
 456                 slotptr++;
 457                 counter--;
 458         }
 459
 460         if ((__u8 *)slotptr >= buflimit) {
 461                 dir_slot *slotptr2;
 462
 463                 if (curclust == 0)
 464                         return -1;
 465                 curclust = get_fatent(mydata, curclust);
 466                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 467                         debug("curclust: 0x%x\n", curclust);
 468                         printf("Invalid FAT entry\n");
 469                         return -1;
 470                 }
 471
 472                 if (get_cluster(mydata, curclust, get_vfatname_block,
 473                                 mydata->clust_size * mydata->sect_size) != 0) {
 474                         debug("Error: reading directory block\n");
 475                         return -1;
 476                 }
 477
 478                 slotptr2 = (dir_slot *)get_vfatname_block;
 479                 while (counter > 0) {
 480                         if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
 481                             & 0xff) != counter)
 482                                 return -1;
 483                         slotptr2++;
 484                         counter--;
 485                 }
 486
 487                 /* Save the real directory entry */
 488                 realdent = (dir_entry *)slotptr2;
 489                 while ((__u8 *)slotptr2 > get_vfatname_block) {
 490                         slotptr2--;
 491                         slot2str(slotptr2, l_name, &idx);
 492                 }
 493         } else {
 494                 /* Save the real directory entry */
 495                 realdent = (dir_entry *)slotptr;
 496         }
 497
 498         do {
 499                 slotptr--;
 500                 if (slot2str(slotptr, l_name, &idx))
 501                         break;
 502         } while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
 503
 504         l_name[idx] = '\0';
 505         if (*l_name == DELETED_FLAG)
 506                 *l_name = '\0';
 507         else if (*l_name == aRING)
 508                 *l_name = DELETED_FLAG;
 509         downcase(l_name);
 510
 511         /* Return the real directory entry */
 512         memcpy(retdent, realdent, sizeof(dir_entry));
 513
 514         return 0;
 515 }
 516
 517 /* Calculate short name checksum */
 518 static __u8 mkcksum (const char *str)
 519 {
 520         int i;
 521
 522         __u8 ret = 0;
 523
 524         for (i = 0; i < 11; i++) {
 525                 ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + str[i];
 526         }
 527
 528         return ret;
 529 }
 530 #endif  /* CONFIG_SUPPORT_VFAT */
 531
 532 /*
 533  * Get the directory entry associated with 'filename' from the directory
 534  * starting at 'startsect'
 535  */
 536 __attribute__ ((__aligned__ (__alignof__ (dir_entry))))
 537 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
 538
 539 static dir_entry *get_dentfromdir (fsdata *mydata, int startsect,
 540                                    char *filename, dir_entry *retdent,
 541                                    int dols)
 542 {
 543         __u16 prevcksum = 0xffff;
 544         __u32 curclust = START(retdent);
 545         int files = 0, dirs = 0;
 546
 547         debug("get_dentfromdir: %s\n", filename);
 548
 549         while (1) {
 550                 dir_entry *dentptr;
 551
 552                 int i;
 553
 554                 if (get_cluster(mydata, curclust, get_dentfromdir_block,
 555                                 mydata->clust_size * mydata->sect_size) != 0) {
 556                         debug("Error: reading directory block\n");
 557                         return NULL;
 558                 }
 559
 560                 dentptr = (dir_entry *)get_dentfromdir_block;
 561
 562                 for (i = 0; i < DIRENTSPERCLUST; i++) {
 563                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 564
 565                         l_name[0] = '\0';
 566                         if (dentptr->name[0] == DELETED_FLAG) {
 567                                 dentptr++;
 568                                 continue;
 569                         }
 570                         if ((dentptr->attr & ATTR_VOLUME)) {
 571 #ifdef CONFIG_SUPPORT_VFAT
 572                                 if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 573                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 574                                         prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 575                                         get_vfatname(mydata, curclust,
 576                                                      get_dentfromdir_block,
 577                                                      dentptr, l_name);
 578                                         if (dols) {
 579                                                 int isdir;
 580                                                 char dirc;
 581                                                 int doit = 0;
 582
 583                                                 isdir = (dentptr->attr & ATTR_DIR);
 584
 585                                                 if (isdir) {
 586                                                         dirs++;
 587                                                         dirc = '/';
 588                                                         doit = 1;
 589                                                 } else {
 590                                                         dirc = ' ';
 591                                                         if (l_name[0] != 0) {
 592                                                                 files++;
 593                                                                 doit = 1;
 594                                                         }
 595                                                 }
 596                                                 if (doit) {
 597                                                         if (dirc == ' ') {
 598                                                                 printf(" %8ld   %s%c\n",
 599                                                                         (long)FAT2CPU32(dentptr->size),
 600                                                                         l_name,
 601                                                                         dirc);
 602                                                         } else {
 603                                                                 printf("            %s%c\n",
 604                                                                         l_name,
 605                                                                         dirc);
 606                                                         }
 607                                                 }
 608                                                 dentptr++;
 609                                                 continue;
 610                                         }
 611                                         debug("vfatname: |%s|\n", l_name);
 612                                 } else
 613 #endif
 614                                 {
 615                                         /* Volume label or VFAT entry */
 616                                         dentptr++;
 617                                         continue;
 618                                 }
 619                         }
 620                         if (dentptr->name[0] == 0) {
 621                                 if (dols) {
 622                                         printf("\n%d file(s), %d dir(s)\n\n",
 623                                                 files, dirs);
 624                                 }
 625                                 debug("Dentname == NULL - %d\n", i);
 626                                 return NULL;
 627                         }
 628 #ifdef CONFIG_SUPPORT_VFAT
 629                         if (dols && mkcksum(dentptr->name) == prevcksum) {
 630                                 prevcksum = 0xffff;
 631                                 dentptr++;
 632                                 continue;
 633                         }
 634 #endif
 635                         get_name(dentptr, s_name);
 636                         if (dols) {
 637                                 int isdir = (dentptr->attr & ATTR_DIR);
 638                                 char dirc;
 639                                 int doit = 0;
 640
 641                                 if (isdir) {
 642                                         dirs++;
 643                                         dirc = '/';
 644                                         doit = 1;
 645                                 } else {
 646                                         dirc = ' ';
 647                                         if (s_name[0] != 0) {
 648                                                 files++;
 649                                                 doit = 1;
 650                                         }
 651                                 }
 652
 653                                 if (doit) {
 654                                         if (dirc == ' ') {
 655                                                 printf(" %8ld   %s%c\n",
 656                                                         (long)FAT2CPU32(dentptr->size),
 657                                                         s_name, dirc);
 658                                         } else {
 659                                                 printf("            %s%c\n",
 660                                                         s_name, dirc);
 661                                         }
 662                                 }
 663
 664                                 dentptr++;
 665                                 continue;
 666                         }
 667
 668                         if (strcmp(filename, s_name)
 669                             && strcmp(filename, l_name)) {
 670                                 debug("Mismatch: |%s|%s|\n", s_name, l_name);
 671                                 dentptr++;
 672                                 continue;
 673                         }
 674
 675                         memcpy(retdent, dentptr, sizeof(dir_entry));
 676
 677                         debug("DentName: %s", s_name);
 678                         debug(", start: 0x%x", START(dentptr));
 679                         debug(", size:  0x%x %s\n",
 680                               FAT2CPU32(dentptr->size),
 681                               (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
 682
 683                         return retdent;
 684                 }
 685
 686                 curclust = get_fatent(mydata, curclust);
 687                 if (CHECK_CLUST(curclust, mydata->fatsize)) {
 688                         debug("curclust: 0x%x\n", curclust);
 689                         printf("Invalid FAT entry\n");
 690                         return NULL;
 691                 }
 692         }
 693
 694         return NULL;
 695 }
 696
 697 /*
 698  * Read boot sector and volume info from a FAT filesystem
 699  */
 700 static int
 701 read_bootsectandvi (boot_sector *bs, volume_info *volinfo, int *fatsize)
 702 {
 703         __u8 *block;
 704         volume_info *vistart;
 705         int ret = 0;
 706
 707         if (cur_dev == NULL) {
 708                 debug("Error: no device selected\n");
 709                 return -1;
 710         }
 711
 712         block = malloc(cur_dev->blksz);
 713         if (block == NULL) {
 714                 debug("Error: allocating block\n");
 715                 return -1;
 716         }
 717
 718         if (disk_read (0, 1, block) < 0) {
 719                 debug("Error: reading block\n");
 720                 goto fail;
 721         }
 722
 723         memcpy(bs, block, sizeof(boot_sector));
 724         bs->reserved = FAT2CPU16(bs->reserved);
 725         bs->fat_length = FAT2CPU16(bs->fat_length);
 726         bs->secs_track = FAT2CPU16(bs->secs_track);
 727         bs->heads = FAT2CPU16(bs->heads);
 728         bs->total_sect = FAT2CPU32(bs->total_sect);
 729
 730         /* FAT32 entries */
 731         if (bs->fat_length == 0) {
 732                 /* Assume FAT32 */
 733                 bs->fat32_length = FAT2CPU32(bs->fat32_length);
 734                 bs->flags = FAT2CPU16(bs->flags);
 735                 bs->root_cluster = FAT2CPU32(bs->root_cluster);
 736                 bs->info_sector = FAT2CPU16(bs->info_sector);
 737                 bs->backup_boot = FAT2CPU16(bs->backup_boot);
 738                 vistart = (volume_info *)(block + sizeof(boot_sector));
 739                 *fatsize = 32;
 740         } else {
 741                 vistart = (volume_info *)&(bs->fat32_length);
 742                 *fatsize = 0;
 743         }
 744         memcpy(volinfo, vistart, sizeof(volume_info));
 745
 746         if (*fatsize == 32) {
 747                 if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
 748                         goto exit;
 749         } else {
 750                 if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 751                         *fatsize = 12;
 752                         goto exit;
 753                 }
 754                 if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
 755                         *fatsize = 16;
 756                         goto exit;
 757                 }
 758         }
 759
 760         debug("Error: broken fs_type sign\n");
 761 fail:
 762         ret = -1;
 763 exit:
 764         free(block);
 765         return ret;
 766 }
 767
 768 __attribute__ ((__aligned__ (__alignof__ (dir_entry))))
 769 __u8 do_fat_read_block[MAX_CLUSTSIZE];
 770
 771 long
 772 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
 773              int dols)
 774 {
 775         char fnamecopy[2048];
 776         boot_sector bs;
 777         volume_info volinfo;
 778         fsdata datablock;
 779         fsdata *mydata = &datablock;
 780         dir_entry *dentptr;
 781         __u16 prevcksum = 0xffff;
 782         char *subname = "";
 783         __u32 cursect;
 784         int idx, isdir = 0;
 785         int files = 0, dirs = 0;
 786         long ret = -1;
 787         int firsttime;
 788         __u32 root_cluster = 0;
 789         int rootdir_size = 0;
 790         int j;
 791
 792         if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
 793                 debug("Error: reading boot sector\n");
 794                 return -1;
 795         }
 796
 797         if (mydata->fatsize == 32) {
 798                 root_cluster = bs.root_cluster;
 799                 mydata->fatlength = bs.fat32_length;
 800         } else {
 801                 mydata->fatlength = bs.fat_length;
 802         }
 803
 804         mydata->fat_sect = bs.reserved;
 805
 806         cursect = mydata->rootdir_sect
 807                 = mydata->fat_sect + mydata->fatlength * bs.fats;
 808
 809         mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
 810         mydata->clust_size = bs.cluster_size;
 811         if (mydata->sect_size != cur_part_info.blksz) {
 812                 printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
 813                                 mydata->sect_size, cur_part_info.blksz);
 814                 return -1;
 815         }
 816
 817         if (mydata->fatsize == 32) {
 818                 mydata->data_begin = mydata->rootdir_sect -
 819                                         (mydata->clust_size * 2);
 820         } else {
 821                 rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 822                                  bs.dir_entries[0]) *
 823                                  sizeof(dir_entry)) /
 824                                  mydata->sect_size;
 825                 mydata->data_begin = mydata->rootdir_sect +
 826                                         rootdir_size -
 827                                         (mydata->clust_size * 2);
 828         }
 829
 830         mydata->fatbufnum = -1;
 831         mydata->fatbuf = malloc(FATBUFSIZE);
 832         if (mydata->fatbuf == NULL) {
 833                 debug("Error: allocating memory\n");
 834                 return -1;
 835         }
 836
 837 #ifdef CONFIG_SUPPORT_VFAT
 838         debug("VFAT Support enabled\n");
 839 #endif
 840         debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 841                mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 842         debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
 843                "Data begins at: %d\n",
 844                root_cluster,
 845                mydata->rootdir_sect,
 846                mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
 847         debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
 848               mydata->clust_size);
 849
 850         /* "cwd" is always the root... */
 851         while (ISDIRDELIM(*filename))
 852                 filename++;
 853
 854         /* Make a copy of the filename and convert it to lowercase */
 855         strcpy(fnamecopy, filename);
 856         downcase(fnamecopy);
 857
 858         if (*fnamecopy == '\0') {
 859                 if (!dols)
 860                         goto exit;
 861
 862                 dols = LS_ROOT;
 863         } else if ((idx = dirdelim(fnamecopy)) >= 0) {
 864                 isdir = 1;
 865                 fnamecopy[idx] = '\0';
 866                 subname = fnamecopy + idx + 1;
 867
 868                 /* Handle multiple delimiters */
 869                 while (ISDIRDELIM(*subname))
 870                         subname++;
 871         } else if (dols) {
 872                 isdir = 1;
 873         }
 874
 875         j = 0;
 876         while (1) {
 877                 int i;
 878
 879                 debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
 880                         cursect, mydata->clust_size, DIRENTSPERBLOCK);
 881
 882                 if (disk_read(cursect,
 883                                 (mydata->fatsize == 32) ?
 884                                 (mydata->clust_size) :
 885                                 PREFETCH_BLOCKS,
 886                                 do_fat_read_block) < 0) {
 887                         debug("Error: reading rootdir block\n");
 888                         goto exit;
 889                 }
 890
 891                 dentptr = (dir_entry *) do_fat_read_block;
 892
 893                 for (i = 0; i < DIRENTSPERBLOCK; i++) {
 894                         char s_name[14], l_name[VFAT_MAXLEN_BYTES];
 895
 896                         l_name[0] = '\0';
 897                         if (dentptr->name[0] == DELETED_FLAG) {
 898                                 dentptr++;
 899                                 continue;
 900                         }
 901                         if ((dentptr->attr & ATTR_VOLUME)) {
 902 #ifdef CONFIG_SUPPORT_VFAT
 903                                 if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 904                                     (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 905                                         prevcksum =
 906                                                 ((dir_slot *)dentptr)->alias_checksum;
 907
 908                                         get_vfatname(mydata,
 909                                                      root_cluster,
 910                                                      do_fat_read_block,
 911                                                      dentptr, l_name);
 912
 913                                         if (dols == LS_ROOT) {
 914                                                 char dirc;
 915                                                 int doit = 0;
 916                                                 int isdir =
 917                                                         (dentptr->attr & ATTR_DIR);
 918
 919                                                 if (isdir) {
 920                                                         dirs++;
 921                                                         dirc = '/';
 922                                                         doit = 1;
 923                                                 } else {
 924                                                         dirc = ' ';
 925                                                         if (l_name[0] != 0) {
 926                                                                 files++;
 927                                                                 doit = 1;
 928                                                         }
 929                                                 }
 930                                                 if (doit) {
 931                                                         if (dirc == ' ') {
 932                                                                 printf(" %8ld   %s%c\n",
 933                                                                         (long)FAT2CPU32(dentptr->size),
 934                                                                         l_name,
 935                                                                         dirc);
 936                                                         } else {
 937                                                                 printf("            %s%c\n",
 938                                                                         l_name,
 939                                                                         dirc);
 940                                                         }
 941                                                 }
 942                                                 dentptr++;
 943                                                 continue;
 944                                         }
 945                                         debug("Rootvfatname: |%s|\n",
 946                                                l_name);
 947                                 } else
 948 #endif
 949                                 {
 950                                         /* Volume label or VFAT entry */
 951                                         dentptr++;
 952                                         continue;
 953                                 }
 954                         } else if (dentptr->name[0] == 0) {
 955                                 debug("RootDentname == NULL - %d\n", i);
 956                                 if (dols == LS_ROOT) {
 957                                         printf("\n%d file(s), %d dir(s)\n\n",
 958                                                 files, dirs);
 959                                         ret = 0;
 960                                 }
 961                                 goto exit;
 962                         }
 963 #ifdef CONFIG_SUPPORT_VFAT
 964                         else if (dols == LS_ROOT &&
 965                                  mkcksum(dentptr->name) == prevcksum) {
 966                                 prevcksum = 0xffff;
 967                                 dentptr++;
 968                                 continue;
 969                         }
 970 #endif
 971                         get_name(dentptr, s_name);
 972
 973                         if (dols == LS_ROOT) {
 974                                 int isdir = (dentptr->attr & ATTR_DIR);
 975                                 char dirc;
 976                                 int doit = 0;
 977
 978                                 if (isdir) {
 979                                         dirc = '/';
 980                                         if (s_name[0] != 0) {
 981                                                 dirs++;
 982                                                 doit = 1;
 983                                         }
 984                                 } else {
 985                                         dirc = ' ';
 986                                         if (s_name[0] != 0) {
 987                                                 files++;
 988                                                 doit = 1;
 989                                         }
 990                                 }
 991                                 if (doit) {
 992                                         if (dirc == ' ') {
 993                                                 printf(" %8ld   %s%c\n",
 994                                                         (long)FAT2CPU32(dentptr->size),
 995                                                         s_name, dirc);
 996                                         } else {
 997                                                 printf("            %s%c\n",
 998                                                         s_name, dirc);
 999                                         }
1000                                 }
1001                                 dentptr++;
1002                                 continue;
1003                         }
1004
1005                         if (strcmp(fnamecopy, s_name)
1006                             && strcmp(fnamecopy, l_name)) {
1007                                 debug("RootMismatch: |%s|%s|\n", s_name,
1008                                        l_name);
1009                                 dentptr++;
1010                                 continue;
1011                         }
1012
1013                         if (isdir && !(dentptr->attr & ATTR_DIR))
1014                                 goto exit;
1015
1016                         debug("RootName: %s", s_name);
1017                         debug(", start: 0x%x", START(dentptr));
1018                         debug(", size:  0x%x %s\n",
1019                                FAT2CPU32(dentptr->size),
1020                                isdir ? "(DIR)" : "");
1021
1022                         goto rootdir_done;      /* We got a match */
1023                 }
1024                 debug("END LOOP: j=%d   clust_size=%d\n", j,
1025                        mydata->clust_size);
1026
1027                 /*
1028                  * On FAT32 we must fetch the FAT entries for the next
1029                  * root directory clusters when a cluster has been
1030                  * completely processed.
1031                  */
1032                 ++j;
1033                 int fat32_end = 0;
1034                 if ((mydata->fatsize == 32) && (j == mydata->clust_size)) {
1035                         int nxtsect = 0;
1036                         int nxt_clust = 0;
1037
1038                         nxt_clust = get_fatent(mydata, root_cluster);
1039                         fat32_end = CHECK_CLUST(nxt_clust, 32);
1040
1041                         nxtsect = mydata->data_begin +
1042                                 (nxt_clust * mydata->clust_size);
1043
1044                         root_cluster = nxt_clust;
1045
1046                         cursect = nxtsect;
1047                         j = 0;
1048                 } else {
1049                         cursect++;
1050                 }
1051
1052                 /* If end of rootdir reached */
1053                 if ((mydata->fatsize == 32 && fat32_end) ||
1054                     (mydata->fatsize != 32 && j == rootdir_size)) {
1055                         if (dols == LS_ROOT) {
1056                                 printf("\n%d file(s), %d dir(s)\n\n",
1057                                        files, dirs);
1058                                 ret = 0;
1059                         }
1060                         goto exit;
1061                 }
1062         }
1063 rootdir_done:
1064
1065         firsttime = 1;
1066
1067         while (isdir) {
1068                 int startsect = mydata->data_begin
1069                         + START(dentptr) * mydata->clust_size;
1070                 dir_entry dent;
1071                 char *nextname = NULL;
1072
1073                 dent = *dentptr;
1074                 dentptr = &dent;
1075
1076                 idx = dirdelim(subname);
1077
1078                 if (idx >= 0) {
1079                         subname[idx] = '\0';
1080                         nextname = subname + idx + 1;
1081                         /* Handle multiple delimiters */
1082                         while (ISDIRDELIM(*nextname))
1083                                 nextname++;
1084                         if (dols && *nextname == '\0')
1085                                 firsttime = 0;
1086                 } else {
1087                         if (dols && firsttime) {
1088                                 firsttime = 0;
1089                         } else {
1090                                 isdir = 0;
1091                         }
1092                 }
1093
1094                 if (get_dentfromdir(mydata, startsect, subname, dentptr,
1095                                      isdir ? 0 : dols) == NULL) {
1096                         if (dols && !isdir)
1097                                 ret = 0;
1098                         goto exit;
1099                 }
1100
1101                 if (idx >= 0) {
1102                         if (!(dentptr->attr & ATTR_DIR))
1103                                 goto exit;
1104                         subname = nextname;
1105                 }
1106         }
1107
1108         ret = get_contents(mydata, dentptr, buffer, maxsize);
1109         debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1110
1111 exit:
1112         free(mydata->fatbuf);
1113         return ret;
1114 }
1115
1116 int file_fat_detectfs (void)
1117 {
1118         boot_sector bs;
1119         volume_info volinfo;
1120         int fatsize;
1121         char vol_label[12];
1122
1123         if (cur_dev == NULL) {
1124                 printf("No current device\n");
1125                 return 1;
1126         }
1127
1128 #if defined(CONFIG_CMD_IDE) || \
1129     defined(CONFIG_CMD_MG_DISK) || \
1130     defined(CONFIG_CMD_SATA) || \
1131     defined(CONFIG_CMD_SCSI) || \
1132     defined(CONFIG_CMD_USB) || \
1133     defined(CONFIG_MMC)
1134         printf("Interface:  ");
1135         switch (cur_dev->if_type) {
1136         case IF_TYPE_IDE:
1137                 printf("IDE");
1138                 break;
1139         case IF_TYPE_SATA:
1140                 printf("SATA");
1141                 break;
1142         case IF_TYPE_SCSI:
1143                 printf("SCSI");
1144                 break;
1145         case IF_TYPE_ATAPI:
1146                 printf("ATAPI");
1147                 break;
1148         case IF_TYPE_USB:
1149                 printf("USB");
1150                 break;
1151         case IF_TYPE_DOC:
1152                 printf("DOC");
1153                 break;
1154         case IF_TYPE_MMC:
1155                 printf("MMC");
1156                 break;
1157         default:
1158                 printf("Unknown");
1159         }
1160
1161         printf("\n  Device %d: ", cur_dev->dev);
1162         dev_print(cur_dev);
1163 #endif
1164
1165         if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1166                 printf("\nNo valid FAT fs found\n");
1167                 return 1;
1168         }
1169
1170         memcpy(vol_label, volinfo.volume_label, 11);
1171         vol_label[11] = '\0';
1172         volinfo.fs_type[5] = '\0';
1173
1174         printf("Partition %d: Filesystem: %s \"%s\"\n", cur_part_nr,
1175                 volinfo.fs_type, vol_label);
1176
1177         return 0;
1178 }
1179
1180 int file_fat_ls (const char *dir)
1181 {
1182         return do_fat_read(dir, NULL, 0, LS_YES);
1183 }
1184
1185 long file_fat_read (const char *filename, void *buffer, unsigned long maxsize)
1186 {
1187         printf("reading %s\n", filename);
1188         return do_fat_read(filename, buffer, maxsize, LS_NO);
1189 }