xref: /rk3399_rockchip-uboot/fs/fat/fat.c (revision 60b36f0fc7c77e98b9d55c237e455c42a1caa44b)
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 = NULL;
47 
48 static unsigned long part_offset = 0;
49 
50 static int cur_part = 1;
51 
52 #define DOS_PART_TBL_OFFSET	0x1be
53 #define DOS_PART_MAGIC_OFFSET	0x1fe
54 #define DOS_FS_TYPE_OFFSET	0x36
55 #define DOS_FS32_TYPE_OFFSET	0x52
56 
57 static int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
58 {
59 	if (cur_dev == NULL)
60 		return -1;
61 
62 	startblock += part_offset;
63 
64 	if (cur_dev->block_read) {
65 		return cur_dev->block_read(cur_dev->dev, startblock, getsize,
66 					   (unsigned long *) bufptr);
67 	}
68 	return -1;
69 }
70 
71 int fat_register_device (block_dev_desc_t * dev_desc, int part_no)
72 {
73 	unsigned char buffer[dev_desc->blksz];
74 	disk_partition_t info;
75 
76 	if (!dev_desc->block_read)
77 		return -1;
78 
79 	cur_dev = dev_desc;
80 	/* check if we have a MBR (on floppies we have only a PBR) */
81 	if (dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *)buffer) != 1) {
82 		printf("** Can't read from device %d **\n",
83 			dev_desc->dev);
84 		return -1;
85 	}
86 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
87 	    buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
88 		/* no signature found */
89 		return -1;
90 	}
91 #if (defined(CONFIG_CMD_IDE) || \
92      defined(CONFIG_CMD_MG_DISK) || \
93      defined(CONFIG_CMD_SATA) || \
94      defined(CONFIG_CMD_SCSI) || \
95      defined(CONFIG_CMD_USB) || \
96      defined(CONFIG_MMC) || \
97      defined(CONFIG_SYSTEMACE) )
98 	/* First we assume there is a MBR */
99 	if (!get_partition_info(dev_desc, part_no, &info)) {
100 		part_offset = info.start;
101 		cur_part = part_no;
102 	} else if ((strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3) == 0) ||
103 		   (strncmp((char *)&buffer[DOS_FS32_TYPE_OFFSET], "FAT32", 5) == 0)) {
104 		/* ok, we assume we are on a PBR only */
105 		cur_part = 1;
106 		part_offset = 0;
107 	} else {
108 		printf("** Partition %d not valid on device %d **\n",
109 			part_no, dev_desc->dev);
110 		return -1;
111 	}
112 
113 #else
114 	if ((strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3) == 0) ||
115 	    (strncmp((char *)&buffer[DOS_FS32_TYPE_OFFSET], "FAT32", 5) == 0)) {
116 		/* ok, we assume we are on a PBR only */
117 		cur_part = 1;
118 		part_offset = 0;
119 		info.start = part_offset;
120 	} else {
121 		/* FIXME we need to determine the start block of the
122 		 * partition where the DOS FS resides. This can be done
123 		 * by using the get_partition_info routine. For this
124 		 * purpose the libpart must be included.
125 		 */
126 		part_offset = 32;
127 		cur_part = 1;
128 	}
129 #endif
130 	return 0;
131 }
132 
133 /*
134  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
135  * Return index into string if found, -1 otherwise.
136  */
137 static int dirdelim (char *str)
138 {
139 	char *start = str;
140 
141 	while (*str != '\0') {
142 		if (ISDIRDELIM(*str))
143 			return str - start;
144 		str++;
145 	}
146 	return -1;
147 }
148 
149 /*
150  * Extract zero terminated short name from a directory entry.
151  */
152 static void get_name (dir_entry *dirent, char *s_name)
153 {
154 	char *ptr;
155 
156 	memcpy(s_name, dirent->name, 8);
157 	s_name[8] = '\0';
158 	ptr = s_name;
159 	while (*ptr && *ptr != ' ')
160 		ptr++;
161 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
162 		*ptr = '.';
163 		ptr++;
164 		memcpy(ptr, dirent->ext, 3);
165 		ptr[3] = '\0';
166 		while (*ptr && *ptr != ' ')
167 			ptr++;
168 	}
169 	*ptr = '\0';
170 	if (*s_name == DELETED_FLAG)
171 		*s_name = '\0';
172 	else if (*s_name == aRING)
173 		*s_name = DELETED_FLAG;
174 	downcase(s_name);
175 }
176 
177 /*
178  * Get the entry at index 'entry' in a FAT (12/16/32) table.
179  * On failure 0x00 is returned.
180  */
181 static __u32 get_fatent (fsdata *mydata, __u32 entry)
182 {
183 	__u32 bufnum;
184 	__u32 off16, offset;
185 	__u32 ret = 0x00;
186 	__u16 val1, val2;
187 
188 	switch (mydata->fatsize) {
189 	case 32:
190 		bufnum = entry / FAT32BUFSIZE;
191 		offset = entry - bufnum * FAT32BUFSIZE;
192 		break;
193 	case 16:
194 		bufnum = entry / FAT16BUFSIZE;
195 		offset = entry - bufnum * FAT16BUFSIZE;
196 		break;
197 	case 12:
198 		bufnum = entry / FAT12BUFSIZE;
199 		offset = entry - bufnum * FAT12BUFSIZE;
200 		break;
201 
202 	default:
203 		/* Unsupported FAT size */
204 		return ret;
205 	}
206 
207 	debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
208 	       mydata->fatsize, entry, entry, offset, offset);
209 
210 	/* Read a new block of FAT entries into the cache. */
211 	if (bufnum != mydata->fatbufnum) {
212 		__u32 getsize = FATBUFBLOCKS;
213 		__u8 *bufptr = mydata->fatbuf;
214 		__u32 fatlength = mydata->fatlength;
215 		__u32 startblock = bufnum * FATBUFBLOCKS;
216 
217 		if (getsize > fatlength)
218 			getsize = fatlength;
219 
220 		fatlength *= mydata->sect_size;	/* We want it in bytes now */
221 		startblock += mydata->fat_sect;	/* Offset from start of disk */
222 
223 		if (disk_read(startblock, getsize, bufptr) < 0) {
224 			debug("Error reading FAT blocks\n");
225 			return ret;
226 		}
227 		mydata->fatbufnum = bufnum;
228 	}
229 
230 	/* Get the actual entry from the table */
231 	switch (mydata->fatsize) {
232 	case 32:
233 		ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
234 		break;
235 	case 16:
236 		ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
237 		break;
238 	case 12:
239 		off16 = (offset * 3) / 4;
240 
241 		switch (offset & 0x3) {
242 		case 0:
243 			ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
244 			ret &= 0xfff;
245 			break;
246 		case 1:
247 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
248 			val1 &= 0xf000;
249 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
250 			val2 &= 0x00ff;
251 			ret = (val2 << 4) | (val1 >> 12);
252 			break;
253 		case 2:
254 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
255 			val1 &= 0xff00;
256 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
257 			val2 &= 0x000f;
258 			ret = (val2 << 8) | (val1 >> 8);
259 			break;
260 		case 3:
261 			ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
262 			ret = (ret & 0xfff0) >> 4;
263 			break;
264 		default:
265 			break;
266 		}
267 		break;
268 	}
269 	debug("FAT%d: ret: %08x, offset: %04x\n",
270 	       mydata->fatsize, ret, offset);
271 
272 	return ret;
273 }
274 
275 /*
276  * Read at most 'size' bytes from the specified cluster into 'buffer'.
277  * Return 0 on success, -1 otherwise.
278  */
279 static int
280 get_cluster (fsdata *mydata, __u32 clustnum, __u8 *buffer,
281 	     unsigned long size)
282 {
283 	__u32 idx = 0;
284 	__u32 startsect;
285 
286 	if (clustnum > 0) {
287 		startsect = mydata->data_begin +
288 				clustnum * mydata->clust_size;
289 	} else {
290 		startsect = mydata->rootdir_sect;
291 	}
292 
293 	debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
294 
295 	if (disk_read(startsect, size / mydata->sect_size, buffer) < 0) {
296 		debug("Error reading data\n");
297 		return -1;
298 	}
299 	if (size % mydata->sect_size) {
300 		__u8 tmpbuf[mydata->sect_size];
301 
302 		idx = size / mydata->sect_size;
303 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
304 			debug("Error reading data\n");
305 			return -1;
306 		}
307 		buffer += idx * mydata->sect_size;
308 
309 		memcpy(buffer, tmpbuf, size % mydata->sect_size);
310 		return 0;
311 	}
312 
313 	return 0;
314 }
315 
316 /*
317  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
318  * into 'buffer'.
319  * Return the number of bytes read or -1 on fatal errors.
320  */
321 static long
322 get_contents (fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
323 	      unsigned long maxsize)
324 {
325 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
326 	unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
327 	__u32 curclust = START(dentptr);
328 	__u32 endclust, newclust;
329 	unsigned long actsize;
330 
331 	debug("Filesize: %ld bytes\n", filesize);
332 
333 	if (maxsize > 0 && filesize > maxsize)
334 		filesize = maxsize;
335 
336 	debug("%ld bytes\n", filesize);
337 
338 	actsize = bytesperclust;
339 	endclust = curclust;
340 
341 	do {
342 		/* search for consecutive clusters */
343 		while (actsize < filesize) {
344 			newclust = get_fatent(mydata, endclust);
345 			if ((newclust - 1) != endclust)
346 				goto getit;
347 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
348 				debug("curclust: 0x%x\n", newclust);
349 				debug("Invalid FAT entry\n");
350 				return gotsize;
351 			}
352 			endclust = newclust;
353 			actsize += bytesperclust;
354 		}
355 
356 		/* actsize >= file size */
357 		actsize -= bytesperclust;
358 
359 		/* get remaining clusters */
360 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
361 			printf("Error reading cluster\n");
362 			return -1;
363 		}
364 
365 		/* get remaining bytes */
366 		gotsize += (int)actsize;
367 		filesize -= actsize;
368 		buffer += actsize;
369 		actsize = filesize;
370 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
371 			printf("Error reading cluster\n");
372 			return -1;
373 		}
374 		gotsize += actsize;
375 		return gotsize;
376 getit:
377 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
378 			printf("Error reading cluster\n");
379 			return -1;
380 		}
381 		gotsize += (int)actsize;
382 		filesize -= actsize;
383 		buffer += actsize;
384 
385 		curclust = get_fatent(mydata, endclust);
386 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
387 			debug("curclust: 0x%x\n", curclust);
388 			printf("Invalid FAT entry\n");
389 			return gotsize;
390 		}
391 		actsize = bytesperclust;
392 		endclust = curclust;
393 	} while (1);
394 }
395 
396 #ifdef CONFIG_SUPPORT_VFAT
397 /*
398  * Extract the file name information from 'slotptr' into 'l_name',
399  * starting at l_name[*idx].
400  * Return 1 if terminator (zero byte) is found, 0 otherwise.
401  */
402 static int slot2str (dir_slot *slotptr, char *l_name, int *idx)
403 {
404 	int j;
405 
406 	for (j = 0; j <= 8; j += 2) {
407 		l_name[*idx] = slotptr->name0_4[j];
408 		if (l_name[*idx] == 0x00)
409 			return 1;
410 		(*idx)++;
411 	}
412 	for (j = 0; j <= 10; j += 2) {
413 		l_name[*idx] = slotptr->name5_10[j];
414 		if (l_name[*idx] == 0x00)
415 			return 1;
416 		(*idx)++;
417 	}
418 	for (j = 0; j <= 2; j += 2) {
419 		l_name[*idx] = slotptr->name11_12[j];
420 		if (l_name[*idx] == 0x00)
421 			return 1;
422 		(*idx)++;
423 	}
424 
425 	return 0;
426 }
427 
428 /*
429  * Extract the full long filename starting at 'retdent' (which is really
430  * a slot) into 'l_name'. If successful also copy the real directory entry
431  * into 'retdent'
432  * Return 0 on success, -1 otherwise.
433  */
434 __attribute__ ((__aligned__ (__alignof__ (dir_entry))))
435 __u8 get_vfatname_block[MAX_CLUSTSIZE];
436 
437 static int
438 get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
439 	      dir_entry *retdent, char *l_name)
440 {
441 	dir_entry *realdent;
442 	dir_slot *slotptr = (dir_slot *)retdent;
443 	__u8 *buflimit = cluster + ((curclust == 0) ?
444 					LINEAR_PREFETCH_SIZE :
445 					(mydata->clust_size * mydata->sect_size)
446 				   );
447 	__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
448 	int idx = 0;
449 
450 	if (counter > VFAT_MAXSEQ) {
451 		debug("Error: VFAT name is too long\n");
452 		return -1;
453 	}
454 
455 	while ((__u8 *)slotptr < buflimit) {
456 		if (counter == 0)
457 			break;
458 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
459 			return -1;
460 		slotptr++;
461 		counter--;
462 	}
463 
464 	if ((__u8 *)slotptr >= buflimit) {
465 		dir_slot *slotptr2;
466 
467 		if (curclust == 0)
468 			return -1;
469 		curclust = get_fatent(mydata, curclust);
470 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
471 			debug("curclust: 0x%x\n", curclust);
472 			printf("Invalid FAT entry\n");
473 			return -1;
474 		}
475 
476 		if (get_cluster(mydata, curclust, get_vfatname_block,
477 				mydata->clust_size * mydata->sect_size) != 0) {
478 			debug("Error: reading directory block\n");
479 			return -1;
480 		}
481 
482 		slotptr2 = (dir_slot *)get_vfatname_block;
483 		while (counter > 0) {
484 			if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
485 			    & 0xff) != counter)
486 				return -1;
487 			slotptr2++;
488 			counter--;
489 		}
490 
491 		/* Save the real directory entry */
492 		realdent = (dir_entry *)slotptr2;
493 		while ((__u8 *)slotptr2 > get_vfatname_block) {
494 			slotptr2--;
495 			slot2str(slotptr2, l_name, &idx);
496 		}
497 	} else {
498 		/* Save the real directory entry */
499 		realdent = (dir_entry *)slotptr;
500 	}
501 
502 	do {
503 		slotptr--;
504 		if (slot2str(slotptr, l_name, &idx))
505 			break;
506 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
507 
508 	l_name[idx] = '\0';
509 	if (*l_name == DELETED_FLAG)
510 		*l_name = '\0';
511 	else if (*l_name == aRING)
512 		*l_name = DELETED_FLAG;
513 	downcase(l_name);
514 
515 	/* Return the real directory entry */
516 	memcpy(retdent, realdent, sizeof(dir_entry));
517 
518 	return 0;
519 }
520 
521 /* Calculate short name checksum */
522 static __u8 mkcksum (const char *str)
523 {
524 	int i;
525 
526 	__u8 ret = 0;
527 
528 	for (i = 0; i < 11; i++) {
529 		ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + str[i];
530 	}
531 
532 	return ret;
533 }
534 #endif	/* CONFIG_SUPPORT_VFAT */
535 
536 /*
537  * Get the directory entry associated with 'filename' from the directory
538  * starting at 'startsect'
539  */
540 __attribute__ ((__aligned__ (__alignof__ (dir_entry))))
541 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
542 
543 static dir_entry *get_dentfromdir (fsdata *mydata, int startsect,
544 				   char *filename, dir_entry *retdent,
545 				   int dols)
546 {
547 	__u16 prevcksum = 0xffff;
548 	__u32 curclust = START(retdent);
549 	int files = 0, dirs = 0;
550 
551 	debug("get_dentfromdir: %s\n", filename);
552 
553 	while (1) {
554 		dir_entry *dentptr;
555 
556 		int i;
557 
558 		if (get_cluster(mydata, curclust, get_dentfromdir_block,
559 				mydata->clust_size * mydata->sect_size) != 0) {
560 			debug("Error: reading directory block\n");
561 			return NULL;
562 		}
563 
564 		dentptr = (dir_entry *)get_dentfromdir_block;
565 
566 		for (i = 0; i < DIRENTSPERCLUST; i++) {
567 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
568 
569 			l_name[0] = '\0';
570 			if (dentptr->name[0] == DELETED_FLAG) {
571 				dentptr++;
572 				continue;
573 			}
574 			if ((dentptr->attr & ATTR_VOLUME)) {
575 #ifdef CONFIG_SUPPORT_VFAT
576 				if ((dentptr->attr & ATTR_VFAT) &&
577 				    (dentptr-> name[0] & LAST_LONG_ENTRY_MASK)) {
578 					prevcksum = ((dir_slot *)dentptr)->alias_checksum;
579 					get_vfatname(mydata, curclust,
580 						     get_dentfromdir_block,
581 						     dentptr, l_name);
582 					if (dols) {
583 						int isdir;
584 						char dirc;
585 						int doit = 0;
586 
587 						isdir = (dentptr->attr & ATTR_DIR);
588 
589 						if (isdir) {
590 							dirs++;
591 							dirc = '/';
592 							doit = 1;
593 						} else {
594 							dirc = ' ';
595 							if (l_name[0] != 0) {
596 								files++;
597 								doit = 1;
598 							}
599 						}
600 						if (doit) {
601 							if (dirc == ' ') {
602 								printf(" %8ld   %s%c\n",
603 									(long)FAT2CPU32(dentptr->size),
604 									l_name,
605 									dirc);
606 							} else {
607 								printf("            %s%c\n",
608 									l_name,
609 									dirc);
610 							}
611 						}
612 						dentptr++;
613 						continue;
614 					}
615 					debug("vfatname: |%s|\n", l_name);
616 				} else
617 #endif
618 				{
619 					/* Volume label or VFAT entry */
620 					dentptr++;
621 					continue;
622 				}
623 			}
624 			if (dentptr->name[0] == 0) {
625 				if (dols) {
626 					printf("\n%d file(s), %d dir(s)\n\n",
627 						files, dirs);
628 				}
629 				debug("Dentname == NULL - %d\n", i);
630 				return NULL;
631 			}
632 #ifdef CONFIG_SUPPORT_VFAT
633 			if (dols && mkcksum(dentptr->name) == prevcksum) {
634 				dentptr++;
635 				continue;
636 			}
637 #endif
638 			get_name(dentptr, s_name);
639 			if (dols) {
640 				int isdir = (dentptr->attr & ATTR_DIR);
641 				char dirc;
642 				int doit = 0;
643 
644 				if (isdir) {
645 					dirs++;
646 					dirc = '/';
647 					doit = 1;
648 				} else {
649 					dirc = ' ';
650 					if (s_name[0] != 0) {
651 						files++;
652 						doit = 1;
653 					}
654 				}
655 
656 				if (doit) {
657 					if (dirc == ' ') {
658 						printf(" %8ld   %s%c\n",
659 							(long)FAT2CPU32(dentptr->size),
660 							s_name, dirc);
661 					} else {
662 						printf("            %s%c\n",
663 							s_name, dirc);
664 					}
665 				}
666 
667 				dentptr++;
668 				continue;
669 			}
670 
671 			if (strcmp(filename, s_name)
672 			    && strcmp(filename, l_name)) {
673 				debug("Mismatch: |%s|%s|\n", s_name, l_name);
674 				dentptr++;
675 				continue;
676 			}
677 
678 			memcpy(retdent, dentptr, sizeof(dir_entry));
679 
680 			debug("DentName: %s", s_name);
681 			debug(", start: 0x%x", START(dentptr));
682 			debug(", size:  0x%x %s\n",
683 			      FAT2CPU32(dentptr->size),
684 			      (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
685 
686 			return retdent;
687 		}
688 
689 		curclust = get_fatent(mydata, curclust);
690 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
691 			debug("curclust: 0x%x\n", curclust);
692 			printf("Invalid FAT entry\n");
693 			return NULL;
694 		}
695 	}
696 
697 	return NULL;
698 }
699 
700 /*
701  * Read boot sector and volume info from a FAT filesystem
702  */
703 static int
704 read_bootsectandvi (boot_sector *bs, volume_info *volinfo, int *fatsize)
705 {
706 	__u8 *block;
707 	volume_info *vistart;
708 	int ret = 0;
709 
710 	if (cur_dev == NULL) {
711 		debug("Error: no device selected\n");
712 		return -1;
713 	}
714 
715 	block = malloc(cur_dev->blksz);
716 	if (block == NULL) {
717 		debug("Error: allocating block\n");
718 		return -1;
719 	}
720 
721 	if (disk_read (0, 1, block) < 0) {
722 		debug("Error: reading block\n");
723 		goto fail;
724 	}
725 
726 	memcpy(bs, block, sizeof(boot_sector));
727 	bs->reserved = FAT2CPU16(bs->reserved);
728 	bs->fat_length = FAT2CPU16(bs->fat_length);
729 	bs->secs_track = FAT2CPU16(bs->secs_track);
730 	bs->heads = FAT2CPU16(bs->heads);
731 	bs->total_sect = FAT2CPU32(bs->total_sect);
732 
733 	/* FAT32 entries */
734 	if (bs->fat_length == 0) {
735 		/* Assume FAT32 */
736 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
737 		bs->flags = FAT2CPU16(bs->flags);
738 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
739 		bs->info_sector = FAT2CPU16(bs->info_sector);
740 		bs->backup_boot = FAT2CPU16(bs->backup_boot);
741 		vistart = (volume_info *)(block + sizeof(boot_sector));
742 		*fatsize = 32;
743 	} else {
744 		vistart = (volume_info *)&(bs->fat32_length);
745 		*fatsize = 0;
746 	}
747 	memcpy(volinfo, vistart, sizeof(volume_info));
748 
749 	if (*fatsize == 32) {
750 		if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
751 			goto exit;
752 	} else {
753 		if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
754 			*fatsize = 12;
755 			goto exit;
756 		}
757 		if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
758 			*fatsize = 16;
759 			goto exit;
760 		}
761 	}
762 
763 	debug("Error: broken fs_type sign\n");
764 fail:
765 	ret = -1;
766 exit:
767 	free(block);
768 	return ret;
769 }
770 
771 __attribute__ ((__aligned__ (__alignof__ (dir_entry))))
772 __u8 do_fat_read_block[MAX_CLUSTSIZE];
773 
774 long
775 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
776 	     int dols)
777 {
778 	char fnamecopy[2048];
779 	boot_sector bs;
780 	volume_info volinfo;
781 	fsdata datablock;
782 	fsdata *mydata = &datablock;
783 	dir_entry *dentptr;
784 	__u16 prevcksum = 0xffff;
785 	char *subname = "";
786 	__u32 cursect;
787 	int idx, isdir = 0;
788 	int files = 0, dirs = 0;
789 	long ret = -1;
790 	int firsttime;
791 	__u32 root_cluster;
792 	int rootdir_size = 0;
793 	int j;
794 
795 	if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
796 		debug("Error: reading boot sector\n");
797 		return -1;
798 	}
799 
800 	root_cluster = bs.root_cluster;
801 
802 	if (mydata->fatsize == 32)
803 		mydata->fatlength = bs.fat32_length;
804 	else
805 		mydata->fatlength = bs.fat_length;
806 
807 	mydata->fat_sect = bs.reserved;
808 
809 	cursect = mydata->rootdir_sect
810 		= mydata->fat_sect + mydata->fatlength * bs.fats;
811 
812 	mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
813 	mydata->clust_size = bs.cluster_size;
814 
815 	if (mydata->fatsize == 32) {
816 		mydata->data_begin = mydata->rootdir_sect -
817 					(mydata->clust_size * 2);
818 	} else {
819 		rootdir_size = ((bs.dir_entries[1]  * (int)256 +
820 				 bs.dir_entries[0]) *
821 				 sizeof(dir_entry)) /
822 				 mydata->sect_size;
823 		mydata->data_begin = mydata->rootdir_sect +
824 					rootdir_size -
825 					(mydata->clust_size * 2);
826 	}
827 
828 	mydata->fatbufnum = -1;
829 	mydata->fatbuf = malloc(FATBUFSIZE);
830 	if (mydata->fatbuf == NULL) {
831 		debug("Error: allocating memory\n");
832 		return -1;
833 	}
834 
835 #ifdef CONFIG_SUPPORT_VFAT
836 	debug("VFAT Support enabled\n");
837 #endif
838 	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
839 	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
840 	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
841 	       "Data begins at: %d\n",
842 	       root_cluster,
843 	       mydata->rootdir_sect,
844 	       mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
845 	debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
846 	      mydata->clust_size);
847 
848 	/* "cwd" is always the root... */
849 	while (ISDIRDELIM(*filename))
850 		filename++;
851 
852 	/* Make a copy of the filename and convert it to lowercase */
853 	strcpy(fnamecopy, filename);
854 	downcase(fnamecopy);
855 
856 	if (*fnamecopy == '\0') {
857 		if (!dols)
858 			goto exit;
859 
860 		dols = LS_ROOT;
861 	} else if ((idx = dirdelim(fnamecopy)) >= 0) {
862 		isdir = 1;
863 		fnamecopy[idx] = '\0';
864 		subname = fnamecopy + idx + 1;
865 
866 		/* Handle multiple delimiters */
867 		while (ISDIRDELIM(*subname))
868 			subname++;
869 	} else if (dols) {
870 		isdir = 1;
871 	}
872 
873 	j = 0;
874 	while (1) {
875 		int i;
876 
877 		debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%d\n",
878 			cursect, mydata->clust_size, DIRENTSPERBLOCK);
879 
880 		if (disk_read(cursect,
881 				(mydata->fatsize == 32) ?
882 				(mydata->clust_size) :
883 				LINEAR_PREFETCH_SIZE / mydata->sect_size,
884 				do_fat_read_block) < 0) {
885 			debug("Error: reading rootdir block\n");
886 			goto exit;
887 		}
888 
889 		dentptr = (dir_entry *) do_fat_read_block;
890 
891 		for (i = 0; i < DIRENTSPERBLOCK; i++) {
892 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
893 
894 			l_name[0] = '\0';
895 			if (dentptr->name[0] == DELETED_FLAG) {
896 				dentptr++;
897 				continue;
898 			}
899 			if ((dentptr->attr & ATTR_VOLUME)) {
900 #ifdef CONFIG_SUPPORT_VFAT
901 				if ((dentptr->attr & ATTR_VFAT) &&
902 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
903 					prevcksum =
904 						((dir_slot *)dentptr)->alias_checksum;
905 
906 					get_vfatname(mydata,
907 						     (mydata->fatsize == 32) ?
908 						     root_cluster :
909 						     0,
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 				dentptr++;
967 				continue;
968 			}
969 #endif
970 			get_name(dentptr, s_name);
971 
972 			if (dols == LS_ROOT) {
973 				int isdir = (dentptr->attr & ATTR_DIR);
974 				char dirc;
975 				int doit = 0;
976 
977 				if (isdir) {
978 					dirc = '/';
979 					if (s_name[0] != 0) {
980 						dirs++;
981 						doit = 1;
982 					}
983 				} else {
984 					dirc = ' ';
985 					if (s_name[0] != 0) {
986 						files++;
987 						doit = 1;
988 					}
989 				}
990 				if (doit) {
991 					if (dirc == ' ') {
992 						printf(" %8ld   %s%c\n",
993 							(long)FAT2CPU32(dentptr->size),
994 							s_name, dirc);
995 					} else {
996 						printf("            %s%c\n",
997 							s_name, dirc);
998 					}
999 				}
1000 				dentptr++;
1001 				continue;
1002 			}
1003 
1004 			if (strcmp(fnamecopy, s_name)
1005 			    && strcmp(fnamecopy, l_name)) {
1006 				debug("RootMismatch: |%s|%s|\n", s_name,
1007 				       l_name);
1008 				dentptr++;
1009 				continue;
1010 			}
1011 
1012 			if (isdir && !(dentptr->attr & ATTR_DIR))
1013 				goto exit;
1014 
1015 			debug("RootName: %s", s_name);
1016 			debug(", start: 0x%x", START(dentptr));
1017 			debug(", size:  0x%x %s\n",
1018 			       FAT2CPU32(dentptr->size),
1019 			       isdir ? "(DIR)" : "");
1020 
1021 			goto rootdir_done;	/* We got a match */
1022 		}
1023 		debug("END LOOP: j=%d   clust_size=%d\n", j,
1024 		       mydata->clust_size);
1025 
1026 		/*
1027 		 * On FAT32 we must fetch the FAT entries for the next
1028 		 * root directory clusters when a cluster has been
1029 		 * completely processed.
1030 		 */
1031 		++j;
1032 		int fat32_end = 0;
1033 		if ((mydata->fatsize == 32) && (j == mydata->clust_size)) {
1034 			int nxtsect = 0;
1035 			int nxt_clust = 0;
1036 
1037 			nxt_clust = get_fatent(mydata, root_cluster);
1038 			fat32_end = CHECK_CLUST(nxt_clust, 32);
1039 
1040 			nxtsect = mydata->data_begin +
1041 				(nxt_clust * mydata->clust_size);
1042 
1043 			root_cluster = nxt_clust;
1044 
1045 			cursect = nxtsect;
1046 			j = 0;
1047 		} else {
1048 			cursect++;
1049 		}
1050 
1051 		/* If end of rootdir reached */
1052 		if ((mydata->fatsize == 32 && fat32_end) ||
1053 		    (mydata->fatsize != 32 && j == rootdir_size)) {
1054 			if (dols == LS_ROOT) {
1055 				printf("\n%d file(s), %d dir(s)\n\n",
1056 				       files, dirs);
1057 				ret = 0;
1058 			}
1059 			goto exit;
1060 		}
1061 	}
1062 rootdir_done:
1063 
1064 	firsttime = 1;
1065 
1066 	while (isdir) {
1067 		int startsect = mydata->data_begin
1068 			+ START(dentptr) * mydata->clust_size;
1069 		dir_entry dent;
1070 		char *nextname = NULL;
1071 
1072 		dent = *dentptr;
1073 		dentptr = &dent;
1074 
1075 		idx = dirdelim(subname);
1076 
1077 		if (idx >= 0) {
1078 			subname[idx] = '\0';
1079 			nextname = subname + idx + 1;
1080 			/* Handle multiple delimiters */
1081 			while (ISDIRDELIM(*nextname))
1082 				nextname++;
1083 			if (dols && *nextname == '\0')
1084 				firsttime = 0;
1085 		} else {
1086 			if (dols && firsttime) {
1087 				firsttime = 0;
1088 			} else {
1089 				isdir = 0;
1090 			}
1091 		}
1092 
1093 		if (get_dentfromdir(mydata, startsect, subname, dentptr,
1094 				     isdir ? 0 : dols) == NULL) {
1095 			if (dols && !isdir)
1096 				ret = 0;
1097 			goto exit;
1098 		}
1099 
1100 		if (idx >= 0) {
1101 			if (!(dentptr->attr & ATTR_DIR))
1102 				goto exit;
1103 			subname = nextname;
1104 		}
1105 	}
1106 
1107 	ret = get_contents(mydata, dentptr, buffer, maxsize);
1108 	debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1109 
1110 exit:
1111 	free(mydata->fatbuf);
1112 	return ret;
1113 }
1114 
1115 int file_fat_detectfs (void)
1116 {
1117 	boot_sector bs;
1118 	volume_info volinfo;
1119 	int fatsize;
1120 	char vol_label[12];
1121 
1122 	if (cur_dev == NULL) {
1123 		printf("No current device\n");
1124 		return 1;
1125 	}
1126 
1127 #if defined(CONFIG_CMD_IDE) || \
1128     defined(CONFIG_CMD_MG_DISK) || \
1129     defined(CONFIG_CMD_SATA) || \
1130     defined(CONFIG_CMD_SCSI) || \
1131     defined(CONFIG_CMD_USB) || \
1132     defined(CONFIG_MMC)
1133 	printf("Interface:  ");
1134 	switch (cur_dev->if_type) {
1135 	case IF_TYPE_IDE:
1136 		printf("IDE");
1137 		break;
1138 	case IF_TYPE_SATA:
1139 		printf("SATA");
1140 		break;
1141 	case IF_TYPE_SCSI:
1142 		printf("SCSI");
1143 		break;
1144 	case IF_TYPE_ATAPI:
1145 		printf("ATAPI");
1146 		break;
1147 	case IF_TYPE_USB:
1148 		printf("USB");
1149 		break;
1150 	case IF_TYPE_DOC:
1151 		printf("DOC");
1152 		break;
1153 	case IF_TYPE_MMC:
1154 		printf("MMC");
1155 		break;
1156 	default:
1157 		printf("Unknown");
1158 	}
1159 
1160 	printf("\n  Device %d: ", cur_dev->dev);
1161 	dev_print(cur_dev);
1162 #endif
1163 
1164 	if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1165 		printf("\nNo valid FAT fs found\n");
1166 		return 1;
1167 	}
1168 
1169 	memcpy(vol_label, volinfo.volume_label, 11);
1170 	vol_label[11] = '\0';
1171 	volinfo.fs_type[5] = '\0';
1172 
1173 	printf("Partition %d: Filesystem: %s \"%s\"\n", cur_part,
1174 		volinfo.fs_type, vol_label);
1175 
1176 	return 0;
1177 }
1178 
1179 int file_fat_ls (const char *dir)
1180 {
1181 	return do_fat_read(dir, NULL, 0, LS_YES);
1182 }
1183 
1184 long file_fat_read (const char *filename, void *buffer, unsigned long maxsize)
1185 {
1186 	printf("reading %s\n", filename);
1187 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1188 }
1189