xref: /rk3399_rockchip-uboot/fs/fat/fat.c (revision cc63b25efb908afa3c1405cd6fce1dd5659f91d7)
1 /*
2  * fat.c
3  *
4  * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
5  *
6  * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
7  * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 #include <common.h>
29 #include <config.h>
30 #include <exports.h>
31 #include <fat.h>
32 #include <asm/byteorder.h>
33 #include <part.h>
34 #include <malloc.h>
35 #include <linux/compiler.h>
36 
37 /*
38  * Convert a string to lowercase.
39  */
40 static void downcase(char *str)
41 {
42 	while (*str != '\0') {
43 		TOLOWER(*str);
44 		str++;
45 	}
46 }
47 
48 static block_dev_desc_t *cur_dev;
49 static unsigned int cur_part_nr;
50 static disk_partition_t cur_part_info;
51 
52 #define DOS_BOOT_MAGIC_OFFSET	0x1fe
53 #define DOS_FS_TYPE_OFFSET	0x36
54 #define DOS_FS32_TYPE_OFFSET	0x52
55 
56 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
57 {
58 	if (!cur_dev || !cur_dev->block_read)
59 		return -1;
60 
61 	return cur_dev->block_read(cur_dev->dev,
62 			cur_part_info.start + block, nr_blocks, buf);
63 }
64 
65 int fat_register_device(block_dev_desc_t * dev_desc, int part_no)
66 {
67 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
68 
69 	/* First close any currently found FAT filesystem */
70 	cur_dev = NULL;
71 
72 #if (defined(CONFIG_CMD_IDE) || \
73      defined(CONFIG_CMD_SATA) || \
74      defined(CONFIG_CMD_SCSI) || \
75      defined(CONFIG_CMD_USB) || \
76      defined(CONFIG_MMC) || \
77      defined(CONFIG_SYSTEMACE) )
78 
79 	/* Read the partition table, if present */
80 	if (!get_partition_info(dev_desc, part_no, &cur_part_info)) {
81 		cur_dev = dev_desc;
82 		cur_part_nr = part_no;
83 	}
84 #endif
85 
86 	/* Otherwise it might be a superfloppy (whole-disk FAT filesystem) */
87 	if (!cur_dev) {
88 		if (part_no != 1) {
89 			printf("** Partition %d not valid on device %d **\n",
90 					part_no, dev_desc->dev);
91 			return -1;
92 		}
93 
94 		cur_dev = dev_desc;
95 		cur_part_nr = 1;
96 		cur_part_info.start = 0;
97 		cur_part_info.size = dev_desc->lba;
98 		cur_part_info.blksz = dev_desc->blksz;
99 		memset(cur_part_info.name, 0, sizeof(cur_part_info.name));
100 		memset(cur_part_info.type, 0, sizeof(cur_part_info.type));
101 	}
102 
103 	/* Make sure it has a valid FAT header */
104 	if (disk_read(0, 1, buffer) != 1) {
105 		cur_dev = NULL;
106 		return -1;
107 	}
108 
109 	/* Check if it's actually a DOS volume */
110 	if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
111 		cur_dev = NULL;
112 		return -1;
113 	}
114 
115 	/* Check for FAT12/FAT16/FAT32 filesystem */
116 	if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
117 		return 0;
118 	if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
119 		return 0;
120 
121 	cur_dev = NULL;
122 	return -1;
123 }
124 
125 
126 /*
127  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
128  * Return index into string if found, -1 otherwise.
129  */
130 static int dirdelim(char *str)
131 {
132 	char *start = str;
133 
134 	while (*str != '\0') {
135 		if (ISDIRDELIM(*str))
136 			return str - start;
137 		str++;
138 	}
139 	return -1;
140 }
141 
142 /*
143  * Extract zero terminated short name from a directory entry.
144  */
145 static void get_name(dir_entry *dirent, char *s_name)
146 {
147 	char *ptr;
148 
149 	memcpy(s_name, dirent->name, 8);
150 	s_name[8] = '\0';
151 	ptr = s_name;
152 	while (*ptr && *ptr != ' ')
153 		ptr++;
154 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
155 		*ptr = '.';
156 		ptr++;
157 		memcpy(ptr, dirent->ext, 3);
158 		ptr[3] = '\0';
159 		while (*ptr && *ptr != ' ')
160 			ptr++;
161 	}
162 	*ptr = '\0';
163 	if (*s_name == DELETED_FLAG)
164 		*s_name = '\0';
165 	else if (*s_name == aRING)
166 		*s_name = DELETED_FLAG;
167 	downcase(s_name);
168 }
169 
170 /*
171  * Get the entry at index 'entry' in a FAT (12/16/32) table.
172  * On failure 0x00 is returned.
173  */
174 static __u32 get_fatent(fsdata *mydata, __u32 entry)
175 {
176 	__u32 bufnum;
177 	__u32 off16, offset;
178 	__u32 ret = 0x00;
179 	__u16 val1, val2;
180 
181 	switch (mydata->fatsize) {
182 	case 32:
183 		bufnum = entry / FAT32BUFSIZE;
184 		offset = entry - bufnum * FAT32BUFSIZE;
185 		break;
186 	case 16:
187 		bufnum = entry / FAT16BUFSIZE;
188 		offset = entry - bufnum * FAT16BUFSIZE;
189 		break;
190 	case 12:
191 		bufnum = entry / FAT12BUFSIZE;
192 		offset = entry - bufnum * FAT12BUFSIZE;
193 		break;
194 
195 	default:
196 		/* Unsupported FAT size */
197 		return ret;
198 	}
199 
200 	debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
201 	       mydata->fatsize, entry, entry, offset, offset);
202 
203 	/* Read a new block of FAT entries into the cache. */
204 	if (bufnum != mydata->fatbufnum) {
205 		__u32 getsize = FATBUFBLOCKS;
206 		__u8 *bufptr = mydata->fatbuf;
207 		__u32 fatlength = mydata->fatlength;
208 		__u32 startblock = bufnum * FATBUFBLOCKS;
209 
210 		if (startblock + getsize > fatlength)
211 			getsize = fatlength - startblock;
212 
213 		startblock += mydata->fat_sect;	/* Offset from start of disk */
214 
215 		if (disk_read(startblock, getsize, bufptr) < 0) {
216 			debug("Error reading FAT blocks\n");
217 			return ret;
218 		}
219 		mydata->fatbufnum = bufnum;
220 	}
221 
222 	/* Get the actual entry from the table */
223 	switch (mydata->fatsize) {
224 	case 32:
225 		ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
226 		break;
227 	case 16:
228 		ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
229 		break;
230 	case 12:
231 		off16 = (offset * 3) / 4;
232 
233 		switch (offset & 0x3) {
234 		case 0:
235 			ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
236 			ret &= 0xfff;
237 			break;
238 		case 1:
239 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
240 			val1 &= 0xf000;
241 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
242 			val2 &= 0x00ff;
243 			ret = (val2 << 4) | (val1 >> 12);
244 			break;
245 		case 2:
246 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
247 			val1 &= 0xff00;
248 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
249 			val2 &= 0x000f;
250 			ret = (val2 << 8) | (val1 >> 8);
251 			break;
252 		case 3:
253 			ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
254 			ret = (ret & 0xfff0) >> 4;
255 			break;
256 		default:
257 			break;
258 		}
259 		break;
260 	}
261 	debug("FAT%d: ret: %08x, offset: %04x\n",
262 	       mydata->fatsize, ret, offset);
263 
264 	return ret;
265 }
266 
267 /*
268  * Read at most 'size' bytes from the specified cluster into 'buffer'.
269  * Return 0 on success, -1 otherwise.
270  */
271 static int
272 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
273 {
274 	__u32 idx = 0;
275 	__u32 startsect;
276 	int ret;
277 
278 	if (clustnum > 0) {
279 		startsect = mydata->data_begin +
280 				clustnum * mydata->clust_size;
281 	} else {
282 		startsect = mydata->rootdir_sect;
283 	}
284 
285 	debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
286 
287 	if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
288 		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
289 
290 		printf("FAT: Misaligned buffer address (%p)\n", buffer);
291 
292 		while (size >= mydata->sect_size) {
293 			ret = disk_read(startsect++, 1, tmpbuf);
294 			if (ret != 1) {
295 				debug("Error reading data (got %d)\n", ret);
296 				return -1;
297 			}
298 
299 			memcpy(buffer, tmpbuf, mydata->sect_size);
300 			buffer += mydata->sect_size;
301 			size -= mydata->sect_size;
302 		}
303 	} else {
304 		idx = size / mydata->sect_size;
305 		ret = disk_read(startsect, idx, buffer);
306 		if (ret != idx) {
307 			debug("Error reading data (got %d)\n", ret);
308 			return -1;
309 		}
310 		startsect += idx;
311 		idx *= mydata->sect_size;
312 		buffer += idx;
313 		size -= idx;
314 	}
315 	if (size) {
316 		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
317 
318 		ret = disk_read(startsect, 1, tmpbuf);
319 		if (ret != 1) {
320 			debug("Error reading data (got %d)\n", ret);
321 			return -1;
322 		}
323 
324 		memcpy(buffer, tmpbuf, size);
325 	}
326 
327 	return 0;
328 }
329 
330 /*
331  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
332  * into 'buffer'.
333  * Return the number of bytes read or -1 on fatal errors.
334  */
335 static long
336 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
337 	     unsigned long maxsize)
338 {
339 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
340 	unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
341 	__u32 curclust = START(dentptr);
342 	__u32 endclust, newclust;
343 	unsigned long actsize;
344 
345 	debug("Filesize: %ld bytes\n", filesize);
346 
347 	if (maxsize > 0 && filesize > maxsize)
348 		filesize = maxsize;
349 
350 	debug("%ld bytes\n", filesize);
351 
352 	actsize = bytesperclust;
353 	endclust = curclust;
354 
355 	do {
356 		/* search for consecutive clusters */
357 		while (actsize < filesize) {
358 			newclust = get_fatent(mydata, endclust);
359 			if ((newclust - 1) != endclust)
360 				goto getit;
361 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
362 				debug("curclust: 0x%x\n", newclust);
363 				debug("Invalid FAT entry\n");
364 				return gotsize;
365 			}
366 			endclust = newclust;
367 			actsize += bytesperclust;
368 		}
369 
370 		/* actsize >= file size */
371 		actsize -= bytesperclust;
372 
373 		/* get remaining clusters */
374 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
375 			printf("Error reading cluster\n");
376 			return -1;
377 		}
378 
379 		/* get remaining bytes */
380 		gotsize += (int)actsize;
381 		filesize -= actsize;
382 		buffer += actsize;
383 		actsize = filesize;
384 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
385 			printf("Error reading cluster\n");
386 			return -1;
387 		}
388 		gotsize += actsize;
389 		return gotsize;
390 getit:
391 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
392 			printf("Error reading cluster\n");
393 			return -1;
394 		}
395 		gotsize += (int)actsize;
396 		filesize -= actsize;
397 		buffer += actsize;
398 
399 		curclust = get_fatent(mydata, endclust);
400 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
401 			debug("curclust: 0x%x\n", curclust);
402 			printf("Invalid FAT entry\n");
403 			return gotsize;
404 		}
405 		actsize = bytesperclust;
406 		endclust = curclust;
407 	} while (1);
408 }
409 
410 #ifdef CONFIG_SUPPORT_VFAT
411 /*
412  * Extract the file name information from 'slotptr' into 'l_name',
413  * starting at l_name[*idx].
414  * Return 1 if terminator (zero byte) is found, 0 otherwise.
415  */
416 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
417 {
418 	int j;
419 
420 	for (j = 0; j <= 8; j += 2) {
421 		l_name[*idx] = slotptr->name0_4[j];
422 		if (l_name[*idx] == 0x00)
423 			return 1;
424 		(*idx)++;
425 	}
426 	for (j = 0; j <= 10; j += 2) {
427 		l_name[*idx] = slotptr->name5_10[j];
428 		if (l_name[*idx] == 0x00)
429 			return 1;
430 		(*idx)++;
431 	}
432 	for (j = 0; j <= 2; j += 2) {
433 		l_name[*idx] = slotptr->name11_12[j];
434 		if (l_name[*idx] == 0x00)
435 			return 1;
436 		(*idx)++;
437 	}
438 
439 	return 0;
440 }
441 
442 /*
443  * Extract the full long filename starting at 'retdent' (which is really
444  * a slot) into 'l_name'. If successful also copy the real directory entry
445  * into 'retdent'
446  * Return 0 on success, -1 otherwise.
447  */
448 __u8 get_vfatname_block[MAX_CLUSTSIZE]
449 	__aligned(ARCH_DMA_MINALIGN);
450 
451 static int
452 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
453 	     dir_entry *retdent, char *l_name)
454 {
455 	dir_entry *realdent;
456 	dir_slot *slotptr = (dir_slot *)retdent;
457 	__u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
458 							PREFETCH_BLOCKS :
459 							mydata->clust_size);
460 	__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
461 	int idx = 0;
462 
463 	if (counter > VFAT_MAXSEQ) {
464 		debug("Error: VFAT name is too long\n");
465 		return -1;
466 	}
467 
468 	while ((__u8 *)slotptr < buflimit) {
469 		if (counter == 0)
470 			break;
471 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
472 			return -1;
473 		slotptr++;
474 		counter--;
475 	}
476 
477 	if ((__u8 *)slotptr >= buflimit) {
478 		dir_slot *slotptr2;
479 
480 		if (curclust == 0)
481 			return -1;
482 		curclust = get_fatent(mydata, curclust);
483 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
484 			debug("curclust: 0x%x\n", curclust);
485 			printf("Invalid FAT entry\n");
486 			return -1;
487 		}
488 
489 		if (get_cluster(mydata, curclust, get_vfatname_block,
490 				mydata->clust_size * mydata->sect_size) != 0) {
491 			debug("Error: reading directory block\n");
492 			return -1;
493 		}
494 
495 		slotptr2 = (dir_slot *)get_vfatname_block;
496 		while (counter > 0) {
497 			if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
498 			    & 0xff) != counter)
499 				return -1;
500 			slotptr2++;
501 			counter--;
502 		}
503 
504 		/* Save the real directory entry */
505 		realdent = (dir_entry *)slotptr2;
506 		while ((__u8 *)slotptr2 > get_vfatname_block) {
507 			slotptr2--;
508 			slot2str(slotptr2, l_name, &idx);
509 		}
510 	} else {
511 		/* Save the real directory entry */
512 		realdent = (dir_entry *)slotptr;
513 	}
514 
515 	do {
516 		slotptr--;
517 		if (slot2str(slotptr, l_name, &idx))
518 			break;
519 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
520 
521 	l_name[idx] = '\0';
522 	if (*l_name == DELETED_FLAG)
523 		*l_name = '\0';
524 	else if (*l_name == aRING)
525 		*l_name = DELETED_FLAG;
526 	downcase(l_name);
527 
528 	/* Return the real directory entry */
529 	memcpy(retdent, realdent, sizeof(dir_entry));
530 
531 	return 0;
532 }
533 
534 /* Calculate short name checksum */
535 static __u8 mkcksum(const char *str)
536 {
537 	int i;
538 
539 	__u8 ret = 0;
540 
541 	for (i = 0; i < 11; i++) {
542 		ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + str[i];
543 	}
544 
545 	return ret;
546 }
547 #endif	/* CONFIG_SUPPORT_VFAT */
548 
549 /*
550  * Get the directory entry associated with 'filename' from the directory
551  * starting at 'startsect'
552  */
553 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
554 	__aligned(ARCH_DMA_MINALIGN);
555 
556 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
557 				  char *filename, dir_entry *retdent,
558 				  int dols)
559 {
560 	__u16 prevcksum = 0xffff;
561 	__u32 curclust = START(retdent);
562 	int files = 0, dirs = 0;
563 
564 	debug("get_dentfromdir: %s\n", filename);
565 
566 	while (1) {
567 		dir_entry *dentptr;
568 
569 		int i;
570 
571 		if (get_cluster(mydata, curclust, get_dentfromdir_block,
572 				mydata->clust_size * mydata->sect_size) != 0) {
573 			debug("Error: reading directory block\n");
574 			return NULL;
575 		}
576 
577 		dentptr = (dir_entry *)get_dentfromdir_block;
578 
579 		for (i = 0; i < DIRENTSPERCLUST; i++) {
580 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
581 
582 			l_name[0] = '\0';
583 			if (dentptr->name[0] == DELETED_FLAG) {
584 				dentptr++;
585 				continue;
586 			}
587 			if ((dentptr->attr & ATTR_VOLUME)) {
588 #ifdef CONFIG_SUPPORT_VFAT
589 				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
590 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
591 					prevcksum = ((dir_slot *)dentptr)->alias_checksum;
592 					get_vfatname(mydata, curclust,
593 						     get_dentfromdir_block,
594 						     dentptr, l_name);
595 					if (dols) {
596 						int isdir;
597 						char dirc;
598 						int doit = 0;
599 
600 						isdir = (dentptr->attr & ATTR_DIR);
601 
602 						if (isdir) {
603 							dirs++;
604 							dirc = '/';
605 							doit = 1;
606 						} else {
607 							dirc = ' ';
608 							if (l_name[0] != 0) {
609 								files++;
610 								doit = 1;
611 							}
612 						}
613 						if (doit) {
614 							if (dirc == ' ') {
615 								printf(" %8ld   %s%c\n",
616 									(long)FAT2CPU32(dentptr->size),
617 									l_name,
618 									dirc);
619 							} else {
620 								printf("            %s%c\n",
621 									l_name,
622 									dirc);
623 							}
624 						}
625 						dentptr++;
626 						continue;
627 					}
628 					debug("vfatname: |%s|\n", l_name);
629 				} else
630 #endif
631 				{
632 					/* Volume label or VFAT entry */
633 					dentptr++;
634 					continue;
635 				}
636 			}
637 			if (dentptr->name[0] == 0) {
638 				if (dols) {
639 					printf("\n%d file(s), %d dir(s)\n\n",
640 						files, dirs);
641 				}
642 				debug("Dentname == NULL - %d\n", i);
643 				return NULL;
644 			}
645 #ifdef CONFIG_SUPPORT_VFAT
646 			if (dols && mkcksum(dentptr->name) == prevcksum) {
647 				prevcksum = 0xffff;
648 				dentptr++;
649 				continue;
650 			}
651 #endif
652 			get_name(dentptr, s_name);
653 			if (dols) {
654 				int isdir = (dentptr->attr & ATTR_DIR);
655 				char dirc;
656 				int doit = 0;
657 
658 				if (isdir) {
659 					dirs++;
660 					dirc = '/';
661 					doit = 1;
662 				} else {
663 					dirc = ' ';
664 					if (s_name[0] != 0) {
665 						files++;
666 						doit = 1;
667 					}
668 				}
669 
670 				if (doit) {
671 					if (dirc == ' ') {
672 						printf(" %8ld   %s%c\n",
673 							(long)FAT2CPU32(dentptr->size),
674 							s_name, dirc);
675 					} else {
676 						printf("            %s%c\n",
677 							s_name, dirc);
678 					}
679 				}
680 
681 				dentptr++;
682 				continue;
683 			}
684 
685 			if (strcmp(filename, s_name)
686 			    && strcmp(filename, l_name)) {
687 				debug("Mismatch: |%s|%s|\n", s_name, l_name);
688 				dentptr++;
689 				continue;
690 			}
691 
692 			memcpy(retdent, dentptr, sizeof(dir_entry));
693 
694 			debug("DentName: %s", s_name);
695 			debug(", start: 0x%x", START(dentptr));
696 			debug(", size:  0x%x %s\n",
697 			      FAT2CPU32(dentptr->size),
698 			      (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
699 
700 			return retdent;
701 		}
702 
703 		curclust = get_fatent(mydata, curclust);
704 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
705 			debug("curclust: 0x%x\n", curclust);
706 			printf("Invalid FAT entry\n");
707 			return NULL;
708 		}
709 	}
710 
711 	return NULL;
712 }
713 
714 /*
715  * Read boot sector and volume info from a FAT filesystem
716  */
717 static int
718 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
719 {
720 	__u8 *block;
721 	volume_info *vistart;
722 	int ret = 0;
723 
724 	if (cur_dev == NULL) {
725 		debug("Error: no device selected\n");
726 		return -1;
727 	}
728 
729 	block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
730 	if (block == NULL) {
731 		debug("Error: allocating block\n");
732 		return -1;
733 	}
734 
735 	if (disk_read(0, 1, block) < 0) {
736 		debug("Error: reading block\n");
737 		goto fail;
738 	}
739 
740 	memcpy(bs, block, sizeof(boot_sector));
741 	bs->reserved = FAT2CPU16(bs->reserved);
742 	bs->fat_length = FAT2CPU16(bs->fat_length);
743 	bs->secs_track = FAT2CPU16(bs->secs_track);
744 	bs->heads = FAT2CPU16(bs->heads);
745 	bs->total_sect = FAT2CPU32(bs->total_sect);
746 
747 	/* FAT32 entries */
748 	if (bs->fat_length == 0) {
749 		/* Assume FAT32 */
750 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
751 		bs->flags = FAT2CPU16(bs->flags);
752 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
753 		bs->info_sector = FAT2CPU16(bs->info_sector);
754 		bs->backup_boot = FAT2CPU16(bs->backup_boot);
755 		vistart = (volume_info *)(block + sizeof(boot_sector));
756 		*fatsize = 32;
757 	} else {
758 		vistart = (volume_info *)&(bs->fat32_length);
759 		*fatsize = 0;
760 	}
761 	memcpy(volinfo, vistart, sizeof(volume_info));
762 
763 	if (*fatsize == 32) {
764 		if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
765 			goto exit;
766 	} else {
767 		if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
768 			*fatsize = 12;
769 			goto exit;
770 		}
771 		if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
772 			*fatsize = 16;
773 			goto exit;
774 		}
775 	}
776 
777 	debug("Error: broken fs_type sign\n");
778 fail:
779 	ret = -1;
780 exit:
781 	free(block);
782 	return ret;
783 }
784 
785 __u8 do_fat_read_block[MAX_CLUSTSIZE]
786 	__aligned(ARCH_DMA_MINALIGN);
787 
788 long
789 do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
790 {
791 	char fnamecopy[2048];
792 	boot_sector bs;
793 	volume_info volinfo;
794 	fsdata datablock;
795 	fsdata *mydata = &datablock;
796 	dir_entry *dentptr = NULL;
797 	__u16 prevcksum = 0xffff;
798 	char *subname = "";
799 	__u32 cursect;
800 	int idx, isdir = 0;
801 	int files = 0, dirs = 0;
802 	long ret = -1;
803 	int firsttime;
804 	__u32 root_cluster = 0;
805 	int rootdir_size = 0;
806 	int j;
807 
808 	if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
809 		debug("Error: reading boot sector\n");
810 		return -1;
811 	}
812 
813 	if (mydata->fatsize == 32) {
814 		root_cluster = bs.root_cluster;
815 		mydata->fatlength = bs.fat32_length;
816 	} else {
817 		mydata->fatlength = bs.fat_length;
818 	}
819 
820 	mydata->fat_sect = bs.reserved;
821 
822 	cursect = mydata->rootdir_sect
823 		= mydata->fat_sect + mydata->fatlength * bs.fats;
824 
825 	mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
826 	mydata->clust_size = bs.cluster_size;
827 	if (mydata->sect_size != cur_part_info.blksz) {
828 		printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
829 				mydata->sect_size, cur_part_info.blksz);
830 		return -1;
831 	}
832 
833 	if (mydata->fatsize == 32) {
834 		mydata->data_begin = mydata->rootdir_sect -
835 					(mydata->clust_size * 2);
836 	} else {
837 		rootdir_size = ((bs.dir_entries[1]  * (int)256 +
838 				 bs.dir_entries[0]) *
839 				 sizeof(dir_entry)) /
840 				 mydata->sect_size;
841 		mydata->data_begin = mydata->rootdir_sect +
842 					rootdir_size -
843 					(mydata->clust_size * 2);
844 	}
845 
846 	mydata->fatbufnum = -1;
847 	mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
848 	if (mydata->fatbuf == NULL) {
849 		debug("Error: allocating memory\n");
850 		return -1;
851 	}
852 
853 #ifdef CONFIG_SUPPORT_VFAT
854 	debug("VFAT Support enabled\n");
855 #endif
856 	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
857 	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
858 	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
859 	       "Data begins at: %d\n",
860 	       root_cluster,
861 	       mydata->rootdir_sect,
862 	       mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
863 	debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
864 	      mydata->clust_size);
865 
866 	/* "cwd" is always the root... */
867 	while (ISDIRDELIM(*filename))
868 		filename++;
869 
870 	/* Make a copy of the filename and convert it to lowercase */
871 	strcpy(fnamecopy, filename);
872 	downcase(fnamecopy);
873 
874 	if (*fnamecopy == '\0') {
875 		if (!dols)
876 			goto exit;
877 
878 		dols = LS_ROOT;
879 	} else if ((idx = dirdelim(fnamecopy)) >= 0) {
880 		isdir = 1;
881 		fnamecopy[idx] = '\0';
882 		subname = fnamecopy + idx + 1;
883 
884 		/* Handle multiple delimiters */
885 		while (ISDIRDELIM(*subname))
886 			subname++;
887 	} else if (dols) {
888 		isdir = 1;
889 	}
890 
891 	j = 0;
892 	while (1) {
893 		int i;
894 
895 		if (j == 0) {
896 			debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
897 				cursect, mydata->clust_size, DIRENTSPERBLOCK);
898 
899 			if (disk_read(cursect,
900 					(mydata->fatsize == 32) ?
901 					(mydata->clust_size) :
902 					PREFETCH_BLOCKS,
903 					do_fat_read_block) < 0) {
904 				debug("Error: reading rootdir block\n");
905 				goto exit;
906 			}
907 
908 			dentptr = (dir_entry *) do_fat_read_block;
909 		}
910 
911 		for (i = 0; i < DIRENTSPERBLOCK; i++) {
912 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
913 
914 			l_name[0] = '\0';
915 			if (dentptr->name[0] == DELETED_FLAG) {
916 				dentptr++;
917 				continue;
918 			}
919 			if ((dentptr->attr & ATTR_VOLUME)) {
920 #ifdef CONFIG_SUPPORT_VFAT
921 				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
922 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
923 					prevcksum =
924 						((dir_slot *)dentptr)->alias_checksum;
925 
926 					get_vfatname(mydata,
927 						     root_cluster,
928 						     do_fat_read_block,
929 						     dentptr, l_name);
930 
931 					if (dols == LS_ROOT) {
932 						char dirc;
933 						int doit = 0;
934 						int isdir =
935 							(dentptr->attr & ATTR_DIR);
936 
937 						if (isdir) {
938 							dirs++;
939 							dirc = '/';
940 							doit = 1;
941 						} else {
942 							dirc = ' ';
943 							if (l_name[0] != 0) {
944 								files++;
945 								doit = 1;
946 							}
947 						}
948 						if (doit) {
949 							if (dirc == ' ') {
950 								printf(" %8ld   %s%c\n",
951 									(long)FAT2CPU32(dentptr->size),
952 									l_name,
953 									dirc);
954 							} else {
955 								printf("            %s%c\n",
956 									l_name,
957 									dirc);
958 							}
959 						}
960 						dentptr++;
961 						continue;
962 					}
963 					debug("Rootvfatname: |%s|\n",
964 					       l_name);
965 				} else
966 #endif
967 				{
968 					/* Volume label or VFAT entry */
969 					dentptr++;
970 					continue;
971 				}
972 			} else if (dentptr->name[0] == 0) {
973 				debug("RootDentname == NULL - %d\n", i);
974 				if (dols == LS_ROOT) {
975 					printf("\n%d file(s), %d dir(s)\n\n",
976 						files, dirs);
977 					ret = 0;
978 				}
979 				goto exit;
980 			}
981 #ifdef CONFIG_SUPPORT_VFAT
982 			else if (dols == LS_ROOT &&
983 				 mkcksum(dentptr->name) == prevcksum) {
984 				prevcksum = 0xffff;
985 				dentptr++;
986 				continue;
987 			}
988 #endif
989 			get_name(dentptr, s_name);
990 
991 			if (dols == LS_ROOT) {
992 				int isdir = (dentptr->attr & ATTR_DIR);
993 				char dirc;
994 				int doit = 0;
995 
996 				if (isdir) {
997 					dirc = '/';
998 					if (s_name[0] != 0) {
999 						dirs++;
1000 						doit = 1;
1001 					}
1002 				} else {
1003 					dirc = ' ';
1004 					if (s_name[0] != 0) {
1005 						files++;
1006 						doit = 1;
1007 					}
1008 				}
1009 				if (doit) {
1010 					if (dirc == ' ') {
1011 						printf(" %8ld   %s%c\n",
1012 							(long)FAT2CPU32(dentptr->size),
1013 							s_name, dirc);
1014 					} else {
1015 						printf("            %s%c\n",
1016 							s_name, dirc);
1017 					}
1018 				}
1019 				dentptr++;
1020 				continue;
1021 			}
1022 
1023 			if (strcmp(fnamecopy, s_name)
1024 			    && strcmp(fnamecopy, l_name)) {
1025 				debug("RootMismatch: |%s|%s|\n", s_name,
1026 				       l_name);
1027 				dentptr++;
1028 				continue;
1029 			}
1030 
1031 			if (isdir && !(dentptr->attr & ATTR_DIR))
1032 				goto exit;
1033 
1034 			debug("RootName: %s", s_name);
1035 			debug(", start: 0x%x", START(dentptr));
1036 			debug(", size:  0x%x %s\n",
1037 			       FAT2CPU32(dentptr->size),
1038 			       isdir ? "(DIR)" : "");
1039 
1040 			goto rootdir_done;	/* We got a match */
1041 		}
1042 		debug("END LOOP: j=%d   clust_size=%d\n", j,
1043 		       mydata->clust_size);
1044 
1045 		/*
1046 		 * On FAT32 we must fetch the FAT entries for the next
1047 		 * root directory clusters when a cluster has been
1048 		 * completely processed.
1049 		 */
1050 		++j;
1051 		int rootdir_end = 0;
1052 		if (mydata->fatsize == 32) {
1053 			if (j == mydata->clust_size) {
1054 				int nxtsect = 0;
1055 				int nxt_clust = 0;
1056 
1057 				nxt_clust = get_fatent(mydata, root_cluster);
1058 				rootdir_end = CHECK_CLUST(nxt_clust, 32);
1059 
1060 				nxtsect = mydata->data_begin +
1061 					(nxt_clust * mydata->clust_size);
1062 
1063 				root_cluster = nxt_clust;
1064 
1065 				cursect = nxtsect;
1066 				j = 0;
1067 			}
1068 		} else {
1069 			if (j == PREFETCH_BLOCKS)
1070 				j = 0;
1071 
1072 			rootdir_end = (++cursect - mydata->rootdir_sect >=
1073 				       rootdir_size);
1074 		}
1075 
1076 		/* If end of rootdir reached */
1077 		if (rootdir_end) {
1078 			if (dols == LS_ROOT) {
1079 				printf("\n%d file(s), %d dir(s)\n\n",
1080 				       files, dirs);
1081 				ret = 0;
1082 			}
1083 			goto exit;
1084 		}
1085 	}
1086 rootdir_done:
1087 
1088 	firsttime = 1;
1089 
1090 	while (isdir) {
1091 		int startsect = mydata->data_begin
1092 			+ START(dentptr) * mydata->clust_size;
1093 		dir_entry dent;
1094 		char *nextname = NULL;
1095 
1096 		dent = *dentptr;
1097 		dentptr = &dent;
1098 
1099 		idx = dirdelim(subname);
1100 
1101 		if (idx >= 0) {
1102 			subname[idx] = '\0';
1103 			nextname = subname + idx + 1;
1104 			/* Handle multiple delimiters */
1105 			while (ISDIRDELIM(*nextname))
1106 				nextname++;
1107 			if (dols && *nextname == '\0')
1108 				firsttime = 0;
1109 		} else {
1110 			if (dols && firsttime) {
1111 				firsttime = 0;
1112 			} else {
1113 				isdir = 0;
1114 			}
1115 		}
1116 
1117 		if (get_dentfromdir(mydata, startsect, subname, dentptr,
1118 				     isdir ? 0 : dols) == NULL) {
1119 			if (dols && !isdir)
1120 				ret = 0;
1121 			goto exit;
1122 		}
1123 
1124 		if (idx >= 0) {
1125 			if (!(dentptr->attr & ATTR_DIR))
1126 				goto exit;
1127 			subname = nextname;
1128 		}
1129 	}
1130 
1131 	ret = get_contents(mydata, dentptr, buffer, maxsize);
1132 	debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1133 
1134 exit:
1135 	free(mydata->fatbuf);
1136 	return ret;
1137 }
1138 
1139 int file_fat_detectfs(void)
1140 {
1141 	boot_sector bs;
1142 	volume_info volinfo;
1143 	int fatsize;
1144 	char vol_label[12];
1145 
1146 	if (cur_dev == NULL) {
1147 		printf("No current device\n");
1148 		return 1;
1149 	}
1150 
1151 #if defined(CONFIG_CMD_IDE) || \
1152     defined(CONFIG_CMD_SATA) || \
1153     defined(CONFIG_CMD_SCSI) || \
1154     defined(CONFIG_CMD_USB) || \
1155     defined(CONFIG_MMC)
1156 	printf("Interface:  ");
1157 	switch (cur_dev->if_type) {
1158 	case IF_TYPE_IDE:
1159 		printf("IDE");
1160 		break;
1161 	case IF_TYPE_SATA:
1162 		printf("SATA");
1163 		break;
1164 	case IF_TYPE_SCSI:
1165 		printf("SCSI");
1166 		break;
1167 	case IF_TYPE_ATAPI:
1168 		printf("ATAPI");
1169 		break;
1170 	case IF_TYPE_USB:
1171 		printf("USB");
1172 		break;
1173 	case IF_TYPE_DOC:
1174 		printf("DOC");
1175 		break;
1176 	case IF_TYPE_MMC:
1177 		printf("MMC");
1178 		break;
1179 	default:
1180 		printf("Unknown");
1181 	}
1182 
1183 	printf("\n  Device %d: ", cur_dev->dev);
1184 	dev_print(cur_dev);
1185 #endif
1186 
1187 	if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1188 		printf("\nNo valid FAT fs found\n");
1189 		return 1;
1190 	}
1191 
1192 	memcpy(vol_label, volinfo.volume_label, 11);
1193 	vol_label[11] = '\0';
1194 	volinfo.fs_type[5] = '\0';
1195 
1196 	printf("Partition %d: Filesystem: %s \"%s\"\n", cur_part_nr,
1197 		volinfo.fs_type, vol_label);
1198 
1199 	return 0;
1200 }
1201 
1202 int file_fat_ls(const char *dir)
1203 {
1204 	return do_fat_read(dir, NULL, 0, LS_YES);
1205 }
1206 
1207 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1208 {
1209 	printf("reading %s\n", filename);
1210 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1211 }
1212