xref: /rk3399_rockchip-uboot/fs/fat/fat.c (revision 8006dd2e57a9b30ff1c978e76c0dcd28d9786ce8)
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 		fatlength *= mydata->sect_size;	/* We want it in bytes now */
214 		startblock += mydata->fat_sect;	/* Offset from start of disk */
215 
216 		if (disk_read(startblock, getsize, bufptr) < 0) {
217 			debug("Error reading FAT blocks\n");
218 			return ret;
219 		}
220 		mydata->fatbufnum = bufnum;
221 	}
222 
223 	/* Get the actual entry from the table */
224 	switch (mydata->fatsize) {
225 	case 32:
226 		ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
227 		break;
228 	case 16:
229 		ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
230 		break;
231 	case 12:
232 		off16 = (offset * 3) / 4;
233 
234 		switch (offset & 0x3) {
235 		case 0:
236 			ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
237 			ret &= 0xfff;
238 			break;
239 		case 1:
240 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
241 			val1 &= 0xf000;
242 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
243 			val2 &= 0x00ff;
244 			ret = (val2 << 4) | (val1 >> 12);
245 			break;
246 		case 2:
247 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
248 			val1 &= 0xff00;
249 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
250 			val2 &= 0x000f;
251 			ret = (val2 << 8) | (val1 >> 8);
252 			break;
253 		case 3:
254 			ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
255 			ret = (ret & 0xfff0) >> 4;
256 			break;
257 		default:
258 			break;
259 		}
260 		break;
261 	}
262 	debug("FAT%d: ret: %08x, offset: %04x\n",
263 	       mydata->fatsize, ret, offset);
264 
265 	return ret;
266 }
267 
268 /*
269  * Read at most 'size' bytes from the specified cluster into 'buffer'.
270  * Return 0 on success, -1 otherwise.
271  */
272 static int
273 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, 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 		ALLOC_CACHE_ALIGN_BUFFER(__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 __u8 get_vfatname_block[MAX_CLUSTSIZE]
432 	__aligned(ARCH_DMA_MINALIGN);
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 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
537 	__aligned(ARCH_DMA_MINALIGN);
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 = memalign(ARCH_DMA_MINALIGN, 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 __u8 do_fat_read_block[MAX_CLUSTSIZE]
769 	__aligned(ARCH_DMA_MINALIGN);
770 
771 long
772 do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
773 {
774 	char fnamecopy[2048];
775 	boot_sector bs;
776 	volume_info volinfo;
777 	fsdata datablock;
778 	fsdata *mydata = &datablock;
779 	dir_entry *dentptr;
780 	__u16 prevcksum = 0xffff;
781 	char *subname = "";
782 	__u32 cursect;
783 	int idx, isdir = 0;
784 	int files = 0, dirs = 0;
785 	long ret = -1;
786 	int firsttime;
787 	__u32 root_cluster = 0;
788 	int rootdir_size = 0;
789 	int j;
790 
791 	if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
792 		debug("Error: reading boot sector\n");
793 		return -1;
794 	}
795 
796 	if (mydata->fatsize == 32) {
797 		root_cluster = bs.root_cluster;
798 		mydata->fatlength = bs.fat32_length;
799 	} else {
800 		mydata->fatlength = bs.fat_length;
801 	}
802 
803 	mydata->fat_sect = bs.reserved;
804 
805 	cursect = mydata->rootdir_sect
806 		= mydata->fat_sect + mydata->fatlength * bs.fats;
807 
808 	mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
809 	mydata->clust_size = bs.cluster_size;
810 	if (mydata->sect_size != cur_part_info.blksz) {
811 		printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
812 				mydata->sect_size, cur_part_info.blksz);
813 		return -1;
814 	}
815 
816 	if (mydata->fatsize == 32) {
817 		mydata->data_begin = mydata->rootdir_sect -
818 					(mydata->clust_size * 2);
819 	} else {
820 		rootdir_size = ((bs.dir_entries[1]  * (int)256 +
821 				 bs.dir_entries[0]) *
822 				 sizeof(dir_entry)) /
823 				 mydata->sect_size;
824 		mydata->data_begin = mydata->rootdir_sect +
825 					rootdir_size -
826 					(mydata->clust_size * 2);
827 	}
828 
829 	mydata->fatbufnum = -1;
830 	mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
831 	if (mydata->fatbuf == NULL) {
832 		debug("Error: allocating memory\n");
833 		return -1;
834 	}
835 
836 #ifdef CONFIG_SUPPORT_VFAT
837 	debug("VFAT Support enabled\n");
838 #endif
839 	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
840 	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
841 	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
842 	       "Data begins at: %d\n",
843 	       root_cluster,
844 	       mydata->rootdir_sect,
845 	       mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
846 	debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
847 	      mydata->clust_size);
848 
849 	/* "cwd" is always the root... */
850 	while (ISDIRDELIM(*filename))
851 		filename++;
852 
853 	/* Make a copy of the filename and convert it to lowercase */
854 	strcpy(fnamecopy, filename);
855 	downcase(fnamecopy);
856 
857 	if (*fnamecopy == '\0') {
858 		if (!dols)
859 			goto exit;
860 
861 		dols = LS_ROOT;
862 	} else if ((idx = dirdelim(fnamecopy)) >= 0) {
863 		isdir = 1;
864 		fnamecopy[idx] = '\0';
865 		subname = fnamecopy + idx + 1;
866 
867 		/* Handle multiple delimiters */
868 		while (ISDIRDELIM(*subname))
869 			subname++;
870 	} else if (dols) {
871 		isdir = 1;
872 	}
873 
874 	j = 0;
875 	while (1) {
876 		int i;
877 
878 		debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
879 			cursect, mydata->clust_size, DIRENTSPERBLOCK);
880 
881 		if (disk_read(cursect,
882 				(mydata->fatsize == 32) ?
883 				(mydata->clust_size) :
884 				PREFETCH_BLOCKS,
885 				do_fat_read_block) < 0) {
886 			debug("Error: reading rootdir block\n");
887 			goto exit;
888 		}
889 
890 		dentptr = (dir_entry *) do_fat_read_block;
891 
892 		for (i = 0; i < DIRENTSPERBLOCK; i++) {
893 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
894 
895 			l_name[0] = '\0';
896 			if (dentptr->name[0] == DELETED_FLAG) {
897 				dentptr++;
898 				continue;
899 			}
900 			if ((dentptr->attr & ATTR_VOLUME)) {
901 #ifdef CONFIG_SUPPORT_VFAT
902 				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
903 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
904 					prevcksum =
905 						((dir_slot *)dentptr)->alias_checksum;
906 
907 					get_vfatname(mydata,
908 						     root_cluster,
909 						     do_fat_read_block,
910 						     dentptr, l_name);
911 
912 					if (dols == LS_ROOT) {
913 						char dirc;
914 						int doit = 0;
915 						int isdir =
916 							(dentptr->attr & ATTR_DIR);
917 
918 						if (isdir) {
919 							dirs++;
920 							dirc = '/';
921 							doit = 1;
922 						} else {
923 							dirc = ' ';
924 							if (l_name[0] != 0) {
925 								files++;
926 								doit = 1;
927 							}
928 						}
929 						if (doit) {
930 							if (dirc == ' ') {
931 								printf(" %8ld   %s%c\n",
932 									(long)FAT2CPU32(dentptr->size),
933 									l_name,
934 									dirc);
935 							} else {
936 								printf("            %s%c\n",
937 									l_name,
938 									dirc);
939 							}
940 						}
941 						dentptr++;
942 						continue;
943 					}
944 					debug("Rootvfatname: |%s|\n",
945 					       l_name);
946 				} else
947 #endif
948 				{
949 					/* Volume label or VFAT entry */
950 					dentptr++;
951 					continue;
952 				}
953 			} else if (dentptr->name[0] == 0) {
954 				debug("RootDentname == NULL - %d\n", i);
955 				if (dols == LS_ROOT) {
956 					printf("\n%d file(s), %d dir(s)\n\n",
957 						files, dirs);
958 					ret = 0;
959 				}
960 				goto exit;
961 			}
962 #ifdef CONFIG_SUPPORT_VFAT
963 			else if (dols == LS_ROOT &&
964 				 mkcksum(dentptr->name) == prevcksum) {
965 				prevcksum = 0xffff;
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_SATA) || \
1129     defined(CONFIG_CMD_SCSI) || \
1130     defined(CONFIG_CMD_USB) || \
1131     defined(CONFIG_MMC)
1132 	printf("Interface:  ");
1133 	switch (cur_dev->if_type) {
1134 	case IF_TYPE_IDE:
1135 		printf("IDE");
1136 		break;
1137 	case IF_TYPE_SATA:
1138 		printf("SATA");
1139 		break;
1140 	case IF_TYPE_SCSI:
1141 		printf("SCSI");
1142 		break;
1143 	case IF_TYPE_ATAPI:
1144 		printf("ATAPI");
1145 		break;
1146 	case IF_TYPE_USB:
1147 		printf("USB");
1148 		break;
1149 	case IF_TYPE_DOC:
1150 		printf("DOC");
1151 		break;
1152 	case IF_TYPE_MMC:
1153 		printf("MMC");
1154 		break;
1155 	default:
1156 		printf("Unknown");
1157 	}
1158 
1159 	printf("\n  Device %d: ", cur_dev->dev);
1160 	dev_print(cur_dev);
1161 #endif
1162 
1163 	if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1164 		printf("\nNo valid FAT fs found\n");
1165 		return 1;
1166 	}
1167 
1168 	memcpy(vol_label, volinfo.volume_label, 11);
1169 	vol_label[11] = '\0';
1170 	volinfo.fs_type[5] = '\0';
1171 
1172 	printf("Partition %d: Filesystem: %s \"%s\"\n", cur_part_nr,
1173 		volinfo.fs_type, vol_label);
1174 
1175 	return 0;
1176 }
1177 
1178 int file_fat_ls(const char *dir)
1179 {
1180 	return do_fat_read(dir, NULL, 0, LS_YES);
1181 }
1182 
1183 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1184 {
1185 	printf("reading %s\n", filename);
1186 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1187 }
1188