xref: /openbmc/u-boot/fs/fat/fat.c (revision 849fc424)
1 /*
2  * fat.c
3  *
4  * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
5  *
6  * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
7  * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
8  *
9  * See file CREDITS for list of people who contributed to this
10  * project.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License as
14  * published by the Free Software Foundation; either version 2 of
15  * the License, or (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25  * MA 02111-1307 USA
26  */
27 
28 #include <common.h>
29 #include <config.h>
30 #include <exports.h>
31 #include <fat.h>
32 #include <asm/byteorder.h>
33 #include <part.h>
34 #include <malloc.h>
35 #include <linux/compiler.h>
36 
37 /*
38  * Convert a string to lowercase.
39  */
40 static void downcase(char *str)
41 {
42 	while (*str != '\0') {
43 		TOLOWER(*str);
44 		str++;
45 	}
46 }
47 
48 static block_dev_desc_t *cur_dev;
49 static unsigned int cur_part_nr;
50 static disk_partition_t cur_part_info;
51 
52 #define DOS_BOOT_MAGIC_OFFSET	0x1fe
53 #define DOS_FS_TYPE_OFFSET	0x36
54 #define DOS_FS32_TYPE_OFFSET	0x52
55 
56 static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
57 {
58 	if (!cur_dev || !cur_dev->block_read)
59 		return -1;
60 
61 	return cur_dev->block_read(cur_dev->dev,
62 			cur_part_info.start + block, nr_blocks, buf);
63 }
64 
65 int fat_register_device(block_dev_desc_t * dev_desc, int part_no)
66 {
67 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
68 
69 	/* First close any currently found FAT filesystem */
70 	cur_dev = NULL;
71 
72 #if (defined(CONFIG_CMD_IDE) || \
73      defined(CONFIG_CMD_SATA) || \
74      defined(CONFIG_CMD_SCSI) || \
75      defined(CONFIG_CMD_USB) || \
76      defined(CONFIG_MMC) || \
77      defined(CONFIG_SYSTEMACE) )
78 
79 	/* Read the partition table, if present */
80 	if (!get_partition_info(dev_desc, part_no, &cur_part_info)) {
81 		cur_dev = dev_desc;
82 		cur_part_nr = part_no;
83 	}
84 #endif
85 
86 	/* Otherwise it might be a superfloppy (whole-disk FAT filesystem) */
87 	if (!cur_dev) {
88 		if (part_no != 1) {
89 			printf("** Partition %d not valid on device %d **\n",
90 					part_no, dev_desc->dev);
91 			return -1;
92 		}
93 
94 		cur_dev = dev_desc;
95 		cur_part_nr = 1;
96 		cur_part_info.start = 0;
97 		cur_part_info.size = dev_desc->lba;
98 		cur_part_info.blksz = dev_desc->blksz;
99 		memset(cur_part_info.name, 0, sizeof(cur_part_info.name));
100 		memset(cur_part_info.type, 0, sizeof(cur_part_info.type));
101 	}
102 
103 	/* Make sure it has a valid FAT header */
104 	if (disk_read(0, 1, buffer) != 1) {
105 		cur_dev = NULL;
106 		return -1;
107 	}
108 
109 	/* Check if it's actually a DOS volume */
110 	if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
111 		cur_dev = NULL;
112 		return -1;
113 	}
114 
115 	/* Check for FAT12/FAT16/FAT32 filesystem */
116 	if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
117 		return 0;
118 	if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
119 		return 0;
120 
121 	cur_dev = NULL;
122 	return -1;
123 }
124 
125 
126 /*
127  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
128  * Return index into string if found, -1 otherwise.
129  */
130 static int dirdelim(char *str)
131 {
132 	char *start = str;
133 
134 	while (*str != '\0') {
135 		if (ISDIRDELIM(*str))
136 			return str - start;
137 		str++;
138 	}
139 	return -1;
140 }
141 
142 /*
143  * Extract zero terminated short name from a directory entry.
144  */
145 static void get_name(dir_entry *dirent, char *s_name)
146 {
147 	char *ptr;
148 
149 	memcpy(s_name, dirent->name, 8);
150 	s_name[8] = '\0';
151 	ptr = s_name;
152 	while (*ptr && *ptr != ' ')
153 		ptr++;
154 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
155 		*ptr = '.';
156 		ptr++;
157 		memcpy(ptr, dirent->ext, 3);
158 		ptr[3] = '\0';
159 		while (*ptr && *ptr != ' ')
160 			ptr++;
161 	}
162 	*ptr = '\0';
163 	if (*s_name == DELETED_FLAG)
164 		*s_name = '\0';
165 	else if (*s_name == aRING)
166 		*s_name = DELETED_FLAG;
167 	downcase(s_name);
168 }
169 
170 /*
171  * Get the entry at index 'entry' in a FAT (12/16/32) table.
172  * On failure 0x00 is returned.
173  */
174 static __u32 get_fatent(fsdata *mydata, __u32 entry)
175 {
176 	__u32 bufnum;
177 	__u32 off16, offset;
178 	__u32 ret = 0x00;
179 	__u16 val1, val2;
180 
181 	switch (mydata->fatsize) {
182 	case 32:
183 		bufnum = entry / FAT32BUFSIZE;
184 		offset = entry - bufnum * FAT32BUFSIZE;
185 		break;
186 	case 16:
187 		bufnum = entry / FAT16BUFSIZE;
188 		offset = entry - bufnum * FAT16BUFSIZE;
189 		break;
190 	case 12:
191 		bufnum = entry / FAT12BUFSIZE;
192 		offset = entry - bufnum * FAT12BUFSIZE;
193 		break;
194 
195 	default:
196 		/* Unsupported FAT size */
197 		return ret;
198 	}
199 
200 	debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
201 	       mydata->fatsize, entry, entry, offset, offset);
202 
203 	/* Read a new block of FAT entries into the cache. */
204 	if (bufnum != mydata->fatbufnum) {
205 		__u32 getsize = FATBUFBLOCKS;
206 		__u8 *bufptr = mydata->fatbuf;
207 		__u32 fatlength = mydata->fatlength;
208 		__u32 startblock = bufnum * FATBUFBLOCKS;
209 
210 		if (startblock + getsize > fatlength)
211 			getsize = fatlength - startblock;
212 
213 		startblock += mydata->fat_sect;	/* Offset from start of disk */
214 
215 		if (disk_read(startblock, getsize, bufptr) < 0) {
216 			debug("Error reading FAT blocks\n");
217 			return ret;
218 		}
219 		mydata->fatbufnum = bufnum;
220 	}
221 
222 	/* Get the actual entry from the table */
223 	switch (mydata->fatsize) {
224 	case 32:
225 		ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
226 		break;
227 	case 16:
228 		ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
229 		break;
230 	case 12:
231 		off16 = (offset * 3) / 4;
232 
233 		switch (offset & 0x3) {
234 		case 0:
235 			ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
236 			ret &= 0xfff;
237 			break;
238 		case 1:
239 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
240 			val1 &= 0xf000;
241 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
242 			val2 &= 0x00ff;
243 			ret = (val2 << 4) | (val1 >> 12);
244 			break;
245 		case 2:
246 			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
247 			val1 &= 0xff00;
248 			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
249 			val2 &= 0x000f;
250 			ret = (val2 << 8) | (val1 >> 8);
251 			break;
252 		case 3:
253 			ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
254 			ret = (ret & 0xfff0) >> 4;
255 			break;
256 		default:
257 			break;
258 		}
259 		break;
260 	}
261 	debug("FAT%d: ret: %08x, offset: %04x\n",
262 	       mydata->fatsize, ret, offset);
263 
264 	return ret;
265 }
266 
267 /*
268  * Read at most 'size' bytes from the specified cluster into 'buffer'.
269  * Return 0 on success, -1 otherwise.
270  */
271 static int
272 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
273 {
274 	__u32 idx = 0;
275 	__u32 startsect;
276 	int ret;
277 
278 	if (clustnum > 0) {
279 		startsect = mydata->data_begin +
280 				clustnum * mydata->clust_size;
281 	} else {
282 		startsect = mydata->rootdir_sect;
283 	}
284 
285 	debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
286 
287 	if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
288 		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
289 
290 		printf("FAT: Misaligned buffer address (%p)\n", buffer);
291 
292 		while (size >= mydata->sect_size) {
293 			ret = disk_read(startsect++, 1, tmpbuf);
294 			if (ret != 1) {
295 				debug("Error reading data (got %d)\n", ret);
296 				return -1;
297 			}
298 
299 			memcpy(buffer, tmpbuf, mydata->sect_size);
300 			buffer += mydata->sect_size;
301 			size -= mydata->sect_size;
302 		}
303 	} else {
304 		idx = size / mydata->sect_size;
305 		ret = disk_read(startsect, idx, buffer);
306 		if (ret != idx) {
307 			debug("Error reading data (got %d)\n", ret);
308 			return -1;
309 		}
310 		startsect += idx;
311 		idx *= mydata->sect_size;
312 		buffer += idx;
313 		size -= idx;
314 	}
315 	if (size) {
316 		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
317 
318 		ret = disk_read(startsect, 1, tmpbuf);
319 		if (ret != 1) {
320 			debug("Error reading data (got %d)\n", ret);
321 			return -1;
322 		}
323 
324 		memcpy(buffer, tmpbuf, size);
325 	}
326 
327 	return 0;
328 }
329 
330 /*
331  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
332  * into 'buffer'.
333  * Return the number of bytes read or -1 on fatal errors.
334  */
335 static long
336 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
337 	     unsigned long maxsize)
338 {
339 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
340 	unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
341 	__u32 curclust = START(dentptr);
342 	__u32 endclust, newclust;
343 	unsigned long actsize;
344 
345 	debug("Filesize: %ld bytes\n", filesize);
346 
347 	if (maxsize > 0 && filesize > maxsize)
348 		filesize = maxsize;
349 
350 	debug("%ld bytes\n", filesize);
351 
352 	actsize = bytesperclust;
353 	endclust = curclust;
354 
355 	do {
356 		/* search for consecutive clusters */
357 		while (actsize < filesize) {
358 			newclust = get_fatent(mydata, endclust);
359 			if ((newclust - 1) != endclust)
360 				goto getit;
361 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
362 				debug("curclust: 0x%x\n", newclust);
363 				debug("Invalid FAT entry\n");
364 				return gotsize;
365 			}
366 			endclust = newclust;
367 			actsize += bytesperclust;
368 		}
369 
370 		/* get remaining bytes */
371 		actsize = filesize;
372 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
373 			printf("Error reading cluster\n");
374 			return -1;
375 		}
376 		gotsize += actsize;
377 		return gotsize;
378 getit:
379 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
380 			printf("Error reading cluster\n");
381 			return -1;
382 		}
383 		gotsize += (int)actsize;
384 		filesize -= actsize;
385 		buffer += actsize;
386 
387 		curclust = get_fatent(mydata, endclust);
388 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
389 			debug("curclust: 0x%x\n", curclust);
390 			printf("Invalid FAT entry\n");
391 			return gotsize;
392 		}
393 		actsize = bytesperclust;
394 		endclust = curclust;
395 	} while (1);
396 }
397 
398 #ifdef CONFIG_SUPPORT_VFAT
399 /*
400  * Extract the file name information from 'slotptr' into 'l_name',
401  * starting at l_name[*idx].
402  * Return 1 if terminator (zero byte) is found, 0 otherwise.
403  */
404 static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
405 {
406 	int j;
407 
408 	for (j = 0; j <= 8; j += 2) {
409 		l_name[*idx] = slotptr->name0_4[j];
410 		if (l_name[*idx] == 0x00)
411 			return 1;
412 		(*idx)++;
413 	}
414 	for (j = 0; j <= 10; j += 2) {
415 		l_name[*idx] = slotptr->name5_10[j];
416 		if (l_name[*idx] == 0x00)
417 			return 1;
418 		(*idx)++;
419 	}
420 	for (j = 0; j <= 2; j += 2) {
421 		l_name[*idx] = slotptr->name11_12[j];
422 		if (l_name[*idx] == 0x00)
423 			return 1;
424 		(*idx)++;
425 	}
426 
427 	return 0;
428 }
429 
430 /*
431  * Extract the full long filename starting at 'retdent' (which is really
432  * a slot) into 'l_name'. If successful also copy the real directory entry
433  * into 'retdent'
434  * Return 0 on success, -1 otherwise.
435  */
436 __u8 get_vfatname_block[MAX_CLUSTSIZE]
437 	__aligned(ARCH_DMA_MINALIGN);
438 
439 static int
440 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
441 	     dir_entry *retdent, char *l_name)
442 {
443 	dir_entry *realdent;
444 	dir_slot *slotptr = (dir_slot *)retdent;
445 	__u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
446 							PREFETCH_BLOCKS :
447 							mydata->clust_size);
448 	__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
449 	int idx = 0;
450 
451 	if (counter > VFAT_MAXSEQ) {
452 		debug("Error: VFAT name is too long\n");
453 		return -1;
454 	}
455 
456 	while ((__u8 *)slotptr < buflimit) {
457 		if (counter == 0)
458 			break;
459 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
460 			return -1;
461 		slotptr++;
462 		counter--;
463 	}
464 
465 	if ((__u8 *)slotptr >= buflimit) {
466 		dir_slot *slotptr2;
467 
468 		if (curclust == 0)
469 			return -1;
470 		curclust = get_fatent(mydata, curclust);
471 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
472 			debug("curclust: 0x%x\n", curclust);
473 			printf("Invalid FAT entry\n");
474 			return -1;
475 		}
476 
477 		if (get_cluster(mydata, curclust, get_vfatname_block,
478 				mydata->clust_size * mydata->sect_size) != 0) {
479 			debug("Error: reading directory block\n");
480 			return -1;
481 		}
482 
483 		slotptr2 = (dir_slot *)get_vfatname_block;
484 		while (counter > 0) {
485 			if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
486 			    & 0xff) != counter)
487 				return -1;
488 			slotptr2++;
489 			counter--;
490 		}
491 
492 		/* Save the real directory entry */
493 		realdent = (dir_entry *)slotptr2;
494 		while ((__u8 *)slotptr2 > get_vfatname_block) {
495 			slotptr2--;
496 			slot2str(slotptr2, l_name, &idx);
497 		}
498 	} else {
499 		/* Save the real directory entry */
500 		realdent = (dir_entry *)slotptr;
501 	}
502 
503 	do {
504 		slotptr--;
505 		if (slot2str(slotptr, l_name, &idx))
506 			break;
507 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
508 
509 	l_name[idx] = '\0';
510 	if (*l_name == DELETED_FLAG)
511 		*l_name = '\0';
512 	else if (*l_name == aRING)
513 		*l_name = DELETED_FLAG;
514 	downcase(l_name);
515 
516 	/* Return the real directory entry */
517 	memcpy(retdent, realdent, sizeof(dir_entry));
518 
519 	return 0;
520 }
521 
522 /* Calculate short name checksum */
523 static __u8 mkcksum(const char *str)
524 {
525 	int i;
526 
527 	__u8 ret = 0;
528 
529 	for (i = 0; i < 11; i++) {
530 		ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + str[i];
531 	}
532 
533 	return ret;
534 }
535 #endif	/* CONFIG_SUPPORT_VFAT */
536 
537 /*
538  * Get the directory entry associated with 'filename' from the directory
539  * starting at 'startsect'
540  */
541 __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
542 	__aligned(ARCH_DMA_MINALIGN);
543 
544 static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
545 				  char *filename, dir_entry *retdent,
546 				  int dols)
547 {
548 	__u16 prevcksum = 0xffff;
549 	__u32 curclust = START(retdent);
550 	int files = 0, dirs = 0;
551 
552 	debug("get_dentfromdir: %s\n", filename);
553 
554 	while (1) {
555 		dir_entry *dentptr;
556 
557 		int i;
558 
559 		if (get_cluster(mydata, curclust, get_dentfromdir_block,
560 				mydata->clust_size * mydata->sect_size) != 0) {
561 			debug("Error: reading directory block\n");
562 			return NULL;
563 		}
564 
565 		dentptr = (dir_entry *)get_dentfromdir_block;
566 
567 		for (i = 0; i < DIRENTSPERCLUST; i++) {
568 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
569 
570 			l_name[0] = '\0';
571 			if (dentptr->name[0] == DELETED_FLAG) {
572 				dentptr++;
573 				continue;
574 			}
575 			if ((dentptr->attr & ATTR_VOLUME)) {
576 #ifdef CONFIG_SUPPORT_VFAT
577 				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
578 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
579 					prevcksum = ((dir_slot *)dentptr)->alias_checksum;
580 					get_vfatname(mydata, curclust,
581 						     get_dentfromdir_block,
582 						     dentptr, l_name);
583 					if (dols) {
584 						int isdir;
585 						char dirc;
586 						int doit = 0;
587 
588 						isdir = (dentptr->attr & ATTR_DIR);
589 
590 						if (isdir) {
591 							dirs++;
592 							dirc = '/';
593 							doit = 1;
594 						} else {
595 							dirc = ' ';
596 							if (l_name[0] != 0) {
597 								files++;
598 								doit = 1;
599 							}
600 						}
601 						if (doit) {
602 							if (dirc == ' ') {
603 								printf(" %8ld   %s%c\n",
604 									(long)FAT2CPU32(dentptr->size),
605 									l_name,
606 									dirc);
607 							} else {
608 								printf("            %s%c\n",
609 									l_name,
610 									dirc);
611 							}
612 						}
613 						dentptr++;
614 						continue;
615 					}
616 					debug("vfatname: |%s|\n", l_name);
617 				} else
618 #endif
619 				{
620 					/* Volume label or VFAT entry */
621 					dentptr++;
622 					continue;
623 				}
624 			}
625 			if (dentptr->name[0] == 0) {
626 				if (dols) {
627 					printf("\n%d file(s), %d dir(s)\n\n",
628 						files, dirs);
629 				}
630 				debug("Dentname == NULL - %d\n", i);
631 				return NULL;
632 			}
633 #ifdef CONFIG_SUPPORT_VFAT
634 			if (dols && mkcksum(dentptr->name) == prevcksum) {
635 				prevcksum = 0xffff;
636 				dentptr++;
637 				continue;
638 			}
639 #endif
640 			get_name(dentptr, s_name);
641 			if (dols) {
642 				int isdir = (dentptr->attr & ATTR_DIR);
643 				char dirc;
644 				int doit = 0;
645 
646 				if (isdir) {
647 					dirs++;
648 					dirc = '/';
649 					doit = 1;
650 				} else {
651 					dirc = ' ';
652 					if (s_name[0] != 0) {
653 						files++;
654 						doit = 1;
655 					}
656 				}
657 
658 				if (doit) {
659 					if (dirc == ' ') {
660 						printf(" %8ld   %s%c\n",
661 							(long)FAT2CPU32(dentptr->size),
662 							s_name, dirc);
663 					} else {
664 						printf("            %s%c\n",
665 							s_name, dirc);
666 					}
667 				}
668 
669 				dentptr++;
670 				continue;
671 			}
672 
673 			if (strcmp(filename, s_name)
674 			    && strcmp(filename, l_name)) {
675 				debug("Mismatch: |%s|%s|\n", s_name, l_name);
676 				dentptr++;
677 				continue;
678 			}
679 
680 			memcpy(retdent, dentptr, sizeof(dir_entry));
681 
682 			debug("DentName: %s", s_name);
683 			debug(", start: 0x%x", START(dentptr));
684 			debug(", size:  0x%x %s\n",
685 			      FAT2CPU32(dentptr->size),
686 			      (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
687 
688 			return retdent;
689 		}
690 
691 		curclust = get_fatent(mydata, curclust);
692 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
693 			debug("curclust: 0x%x\n", curclust);
694 			printf("Invalid FAT entry\n");
695 			return NULL;
696 		}
697 	}
698 
699 	return NULL;
700 }
701 
702 /*
703  * Read boot sector and volume info from a FAT filesystem
704  */
705 static int
706 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
707 {
708 	__u8 *block;
709 	volume_info *vistart;
710 	int ret = 0;
711 
712 	if (cur_dev == NULL) {
713 		debug("Error: no device selected\n");
714 		return -1;
715 	}
716 
717 	block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
718 	if (block == NULL) {
719 		debug("Error: allocating block\n");
720 		return -1;
721 	}
722 
723 	if (disk_read(0, 1, block) < 0) {
724 		debug("Error: reading block\n");
725 		goto fail;
726 	}
727 
728 	memcpy(bs, block, sizeof(boot_sector));
729 	bs->reserved = FAT2CPU16(bs->reserved);
730 	bs->fat_length = FAT2CPU16(bs->fat_length);
731 	bs->secs_track = FAT2CPU16(bs->secs_track);
732 	bs->heads = FAT2CPU16(bs->heads);
733 	bs->total_sect = FAT2CPU32(bs->total_sect);
734 
735 	/* FAT32 entries */
736 	if (bs->fat_length == 0) {
737 		/* Assume FAT32 */
738 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
739 		bs->flags = FAT2CPU16(bs->flags);
740 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
741 		bs->info_sector = FAT2CPU16(bs->info_sector);
742 		bs->backup_boot = FAT2CPU16(bs->backup_boot);
743 		vistart = (volume_info *)(block + sizeof(boot_sector));
744 		*fatsize = 32;
745 	} else {
746 		vistart = (volume_info *)&(bs->fat32_length);
747 		*fatsize = 0;
748 	}
749 	memcpy(volinfo, vistart, sizeof(volume_info));
750 
751 	if (*fatsize == 32) {
752 		if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
753 			goto exit;
754 	} else {
755 		if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
756 			*fatsize = 12;
757 			goto exit;
758 		}
759 		if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
760 			*fatsize = 16;
761 			goto exit;
762 		}
763 	}
764 
765 	debug("Error: broken fs_type sign\n");
766 fail:
767 	ret = -1;
768 exit:
769 	free(block);
770 	return ret;
771 }
772 
773 __u8 do_fat_read_block[MAX_CLUSTSIZE]
774 	__aligned(ARCH_DMA_MINALIGN);
775 
776 long
777 do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
778 {
779 	char fnamecopy[2048];
780 	boot_sector bs;
781 	volume_info volinfo;
782 	fsdata datablock;
783 	fsdata *mydata = &datablock;
784 	dir_entry *dentptr = NULL;
785 	__u16 prevcksum = 0xffff;
786 	char *subname = "";
787 	__u32 cursect;
788 	int idx, isdir = 0;
789 	int files = 0, dirs = 0;
790 	long ret = -1;
791 	int firsttime;
792 	__u32 root_cluster = 0;
793 	int rootdir_size = 0;
794 	int j;
795 
796 	if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
797 		debug("Error: reading boot sector\n");
798 		return -1;
799 	}
800 
801 	if (mydata->fatsize == 32) {
802 		root_cluster = bs.root_cluster;
803 		mydata->fatlength = bs.fat32_length;
804 	} else {
805 		mydata->fatlength = bs.fat_length;
806 	}
807 
808 	mydata->fat_sect = bs.reserved;
809 
810 	cursect = mydata->rootdir_sect
811 		= mydata->fat_sect + mydata->fatlength * bs.fats;
812 
813 	mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
814 	mydata->clust_size = bs.cluster_size;
815 	if (mydata->sect_size != cur_part_info.blksz) {
816 		printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
817 				mydata->sect_size, cur_part_info.blksz);
818 		return -1;
819 	}
820 
821 	if (mydata->fatsize == 32) {
822 		mydata->data_begin = mydata->rootdir_sect -
823 					(mydata->clust_size * 2);
824 	} else {
825 		rootdir_size = ((bs.dir_entries[1]  * (int)256 +
826 				 bs.dir_entries[0]) *
827 				 sizeof(dir_entry)) /
828 				 mydata->sect_size;
829 		mydata->data_begin = mydata->rootdir_sect +
830 					rootdir_size -
831 					(mydata->clust_size * 2);
832 	}
833 
834 	mydata->fatbufnum = -1;
835 	mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
836 	if (mydata->fatbuf == NULL) {
837 		debug("Error: allocating memory\n");
838 		return -1;
839 	}
840 
841 #ifdef CONFIG_SUPPORT_VFAT
842 	debug("VFAT Support enabled\n");
843 #endif
844 	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
845 	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
846 	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
847 	       "Data begins at: %d\n",
848 	       root_cluster,
849 	       mydata->rootdir_sect,
850 	       mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
851 	debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
852 	      mydata->clust_size);
853 
854 	/* "cwd" is always the root... */
855 	while (ISDIRDELIM(*filename))
856 		filename++;
857 
858 	/* Make a copy of the filename and convert it to lowercase */
859 	strcpy(fnamecopy, filename);
860 	downcase(fnamecopy);
861 
862 	if (*fnamecopy == '\0') {
863 		if (!dols)
864 			goto exit;
865 
866 		dols = LS_ROOT;
867 	} else if ((idx = dirdelim(fnamecopy)) >= 0) {
868 		isdir = 1;
869 		fnamecopy[idx] = '\0';
870 		subname = fnamecopy + idx + 1;
871 
872 		/* Handle multiple delimiters */
873 		while (ISDIRDELIM(*subname))
874 			subname++;
875 	} else if (dols) {
876 		isdir = 1;
877 	}
878 
879 	j = 0;
880 	while (1) {
881 		int i;
882 
883 		if (j == 0) {
884 			debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
885 				cursect, mydata->clust_size, DIRENTSPERBLOCK);
886 
887 			if (disk_read(cursect,
888 					(mydata->fatsize == 32) ?
889 					(mydata->clust_size) :
890 					PREFETCH_BLOCKS,
891 					do_fat_read_block) < 0) {
892 				debug("Error: reading rootdir block\n");
893 				goto exit;
894 			}
895 
896 			dentptr = (dir_entry *) do_fat_read_block;
897 		}
898 
899 		for (i = 0; i < DIRENTSPERBLOCK; i++) {
900 			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
901 
902 			l_name[0] = '\0';
903 			if (dentptr->name[0] == DELETED_FLAG) {
904 				dentptr++;
905 				continue;
906 			}
907 			if ((dentptr->attr & ATTR_VOLUME)) {
908 #ifdef CONFIG_SUPPORT_VFAT
909 				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
910 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
911 					prevcksum =
912 						((dir_slot *)dentptr)->alias_checksum;
913 
914 					get_vfatname(mydata,
915 						     root_cluster,
916 						     do_fat_read_block,
917 						     dentptr, l_name);
918 
919 					if (dols == LS_ROOT) {
920 						char dirc;
921 						int doit = 0;
922 						int isdir =
923 							(dentptr->attr & ATTR_DIR);
924 
925 						if (isdir) {
926 							dirs++;
927 							dirc = '/';
928 							doit = 1;
929 						} else {
930 							dirc = ' ';
931 							if (l_name[0] != 0) {
932 								files++;
933 								doit = 1;
934 							}
935 						}
936 						if (doit) {
937 							if (dirc == ' ') {
938 								printf(" %8ld   %s%c\n",
939 									(long)FAT2CPU32(dentptr->size),
940 									l_name,
941 									dirc);
942 							} else {
943 								printf("            %s%c\n",
944 									l_name,
945 									dirc);
946 							}
947 						}
948 						dentptr++;
949 						continue;
950 					}
951 					debug("Rootvfatname: |%s|\n",
952 					       l_name);
953 				} else
954 #endif
955 				{
956 					/* Volume label or VFAT entry */
957 					dentptr++;
958 					continue;
959 				}
960 			} else if (dentptr->name[0] == 0) {
961 				debug("RootDentname == NULL - %d\n", i);
962 				if (dols == LS_ROOT) {
963 					printf("\n%d file(s), %d dir(s)\n\n",
964 						files, dirs);
965 					ret = 0;
966 				}
967 				goto exit;
968 			}
969 #ifdef CONFIG_SUPPORT_VFAT
970 			else if (dols == LS_ROOT &&
971 				 mkcksum(dentptr->name) == prevcksum) {
972 				prevcksum = 0xffff;
973 				dentptr++;
974 				continue;
975 			}
976 #endif
977 			get_name(dentptr, s_name);
978 
979 			if (dols == LS_ROOT) {
980 				int isdir = (dentptr->attr & ATTR_DIR);
981 				char dirc;
982 				int doit = 0;
983 
984 				if (isdir) {
985 					dirc = '/';
986 					if (s_name[0] != 0) {
987 						dirs++;
988 						doit = 1;
989 					}
990 				} else {
991 					dirc = ' ';
992 					if (s_name[0] != 0) {
993 						files++;
994 						doit = 1;
995 					}
996 				}
997 				if (doit) {
998 					if (dirc == ' ') {
999 						printf(" %8ld   %s%c\n",
1000 							(long)FAT2CPU32(dentptr->size),
1001 							s_name, dirc);
1002 					} else {
1003 						printf("            %s%c\n",
1004 							s_name, dirc);
1005 					}
1006 				}
1007 				dentptr++;
1008 				continue;
1009 			}
1010 
1011 			if (strcmp(fnamecopy, s_name)
1012 			    && strcmp(fnamecopy, l_name)) {
1013 				debug("RootMismatch: |%s|%s|\n", s_name,
1014 				       l_name);
1015 				dentptr++;
1016 				continue;
1017 			}
1018 
1019 			if (isdir && !(dentptr->attr & ATTR_DIR))
1020 				goto exit;
1021 
1022 			debug("RootName: %s", s_name);
1023 			debug(", start: 0x%x", START(dentptr));
1024 			debug(", size:  0x%x %s\n",
1025 			       FAT2CPU32(dentptr->size),
1026 			       isdir ? "(DIR)" : "");
1027 
1028 			goto rootdir_done;	/* We got a match */
1029 		}
1030 		debug("END LOOP: j=%d   clust_size=%d\n", j,
1031 		       mydata->clust_size);
1032 
1033 		/*
1034 		 * On FAT32 we must fetch the FAT entries for the next
1035 		 * root directory clusters when a cluster has been
1036 		 * completely processed.
1037 		 */
1038 		++j;
1039 		int rootdir_end = 0;
1040 		if (mydata->fatsize == 32) {
1041 			if (j == mydata->clust_size) {
1042 				int nxtsect = 0;
1043 				int nxt_clust = 0;
1044 
1045 				nxt_clust = get_fatent(mydata, root_cluster);
1046 				rootdir_end = CHECK_CLUST(nxt_clust, 32);
1047 
1048 				nxtsect = mydata->data_begin +
1049 					(nxt_clust * mydata->clust_size);
1050 
1051 				root_cluster = nxt_clust;
1052 
1053 				cursect = nxtsect;
1054 				j = 0;
1055 			}
1056 		} else {
1057 			if (j == PREFETCH_BLOCKS)
1058 				j = 0;
1059 
1060 			rootdir_end = (++cursect - mydata->rootdir_sect >=
1061 				       rootdir_size);
1062 		}
1063 
1064 		/* If end of rootdir reached */
1065 		if (rootdir_end) {
1066 			if (dols == LS_ROOT) {
1067 				printf("\n%d file(s), %d dir(s)\n\n",
1068 				       files, dirs);
1069 				ret = 0;
1070 			}
1071 			goto exit;
1072 		}
1073 	}
1074 rootdir_done:
1075 
1076 	firsttime = 1;
1077 
1078 	while (isdir) {
1079 		int startsect = mydata->data_begin
1080 			+ START(dentptr) * mydata->clust_size;
1081 		dir_entry dent;
1082 		char *nextname = NULL;
1083 
1084 		dent = *dentptr;
1085 		dentptr = &dent;
1086 
1087 		idx = dirdelim(subname);
1088 
1089 		if (idx >= 0) {
1090 			subname[idx] = '\0';
1091 			nextname = subname + idx + 1;
1092 			/* Handle multiple delimiters */
1093 			while (ISDIRDELIM(*nextname))
1094 				nextname++;
1095 			if (dols && *nextname == '\0')
1096 				firsttime = 0;
1097 		} else {
1098 			if (dols && firsttime) {
1099 				firsttime = 0;
1100 			} else {
1101 				isdir = 0;
1102 			}
1103 		}
1104 
1105 		if (get_dentfromdir(mydata, startsect, subname, dentptr,
1106 				     isdir ? 0 : dols) == NULL) {
1107 			if (dols && !isdir)
1108 				ret = 0;
1109 			goto exit;
1110 		}
1111 
1112 		if (isdir && !(dentptr->attr & ATTR_DIR))
1113 			goto exit;
1114 
1115 		if (idx >= 0)
1116 			subname = nextname;
1117 	}
1118 
1119 	ret = get_contents(mydata, dentptr, buffer, maxsize);
1120 	debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1121 
1122 exit:
1123 	free(mydata->fatbuf);
1124 	return ret;
1125 }
1126 
1127 int file_fat_detectfs(void)
1128 {
1129 	boot_sector bs;
1130 	volume_info volinfo;
1131 	int fatsize;
1132 	char vol_label[12];
1133 
1134 	if (cur_dev == NULL) {
1135 		printf("No current device\n");
1136 		return 1;
1137 	}
1138 
1139 #if defined(CONFIG_CMD_IDE) || \
1140     defined(CONFIG_CMD_SATA) || \
1141     defined(CONFIG_CMD_SCSI) || \
1142     defined(CONFIG_CMD_USB) || \
1143     defined(CONFIG_MMC)
1144 	printf("Interface:  ");
1145 	switch (cur_dev->if_type) {
1146 	case IF_TYPE_IDE:
1147 		printf("IDE");
1148 		break;
1149 	case IF_TYPE_SATA:
1150 		printf("SATA");
1151 		break;
1152 	case IF_TYPE_SCSI:
1153 		printf("SCSI");
1154 		break;
1155 	case IF_TYPE_ATAPI:
1156 		printf("ATAPI");
1157 		break;
1158 	case IF_TYPE_USB:
1159 		printf("USB");
1160 		break;
1161 	case IF_TYPE_DOC:
1162 		printf("DOC");
1163 		break;
1164 	case IF_TYPE_MMC:
1165 		printf("MMC");
1166 		break;
1167 	default:
1168 		printf("Unknown");
1169 	}
1170 
1171 	printf("\n  Device %d: ", cur_dev->dev);
1172 	dev_print(cur_dev);
1173 #endif
1174 
1175 	if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1176 		printf("\nNo valid FAT fs found\n");
1177 		return 1;
1178 	}
1179 
1180 	memcpy(vol_label, volinfo.volume_label, 11);
1181 	vol_label[11] = '\0';
1182 	volinfo.fs_type[5] = '\0';
1183 
1184 	printf("Partition %d: Filesystem: %s \"%s\"\n", cur_part_nr,
1185 		volinfo.fs_type, vol_label);
1186 
1187 	return 0;
1188 }
1189 
1190 int file_fat_ls(const char *dir)
1191 {
1192 	return do_fat_read(dir, NULL, 0, LS_YES);
1193 }
1194 
1195 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1196 {
1197 	printf("reading %s\n", filename);
1198 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1199 }
1200