xref: /rk3399_rockchip-uboot/fs/fat/fat.c (revision 2d5b561e2bfdee8552a99b2cf93016cce2a74895)
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 <fat.h>
31 #include <asm/byteorder.h>
32 #include <part.h>
33 
34 #if (CONFIG_COMMANDS & CFG_CMD_FAT)
35 
36 #ifdef CONFIG_AUTO_UPDATE
37 /* the VFAT code has a bug which breaks auto update */
38 #undef CONFIG_SUPPORT_VFAT
39 #endif
40 
41 /*
42  * Convert a string to lowercase.
43  */
44 static void
45 downcase(char *str)
46 {
47 	while (*str != '\0') {
48 		TOLOWER(*str);
49 		str++;
50 	}
51 }
52 
53 static  block_dev_desc_t *cur_dev = NULL;
54 static unsigned long part_offset = 0;
55 static int cur_part = 1;
56 
57 #define DOS_PART_TBL_OFFSET	0x1be
58 #define DOS_PART_MAGIC_OFFSET	0x1fe
59 #define DOS_FS_TYPE_OFFSET	0x36
60 
61 int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
62 {
63 	startblock += part_offset;
64 	if (cur_dev == NULL)
65 		return -1;
66 	if (cur_dev->block_read) {
67 		return cur_dev->block_read (cur_dev->dev, startblock, getsize, (unsigned long *)bufptr);
68 	}
69 	return -1;
70 }
71 
72 
73 int
74 fat_register_device(block_dev_desc_t *dev_desc, int part_no)
75 {
76 	unsigned char buffer[SECTOR_SIZE];
77 
78 	if (!dev_desc->block_read)
79 		return -1;
80 	cur_dev=dev_desc;
81 	/* check if we have a MBR (on floppies we have only a PBR) */
82 	if (dev_desc->block_read (dev_desc->dev, 0, 1, (ulong *) buffer) != 1) {
83 		printf ("** Can't read from device %d **\n", dev_desc->dev);
84 		return -1;
85 	}
86 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
87 		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
88 		/* no signature found */
89 		return -1;
90 	}
91 	if(!strncmp(&buffer[DOS_FS_TYPE_OFFSET],"FAT",3)) {
92 		/* ok, we assume we are on a PBR only */
93 		cur_part = 1;
94 		part_offset=0;
95 	}
96 	else {
97 #if (CONFIG_COMMANDS & CFG_CMD_IDE) || (CONFIG_COMMANDS & CFG_CMD_SCSI)
98 		disk_partition_t info;
99 		if(!get_partition_info(dev_desc, part_no, &info)) {
100 			part_offset = info.start;
101 			cur_part = part_no;
102 		}
103 		else {
104 			printf ("** Partition %d not valid on device %d **\n",part_no,dev_desc->dev);
105 			return -1;
106 		}
107 #else
108 		/* FIXME we need to determine the start block of the
109 		 * partition where the DOS FS resides. This can be done
110 		 * by using the get_partition_info routine. For this
111 		 * purpose the libpart must be included.
112 		 */
113 		part_offset=32;
114 		cur_part = 1;
115 #endif
116 	}
117 	return 0;
118 }
119 
120 
121 /*
122  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
123  * Return index into string if found, -1 otherwise.
124  */
125 static int
126 dirdelim(char *str)
127 {
128 	char *start = str;
129 
130 	while (*str != '\0') {
131 		if (ISDIRDELIM(*str)) return str - start;
132 		str++;
133 	}
134 	return -1;
135 }
136 
137 
138 /*
139  * Match volume_info fs_type strings.
140  * Return 0 on match, -1 otherwise.
141  */
142 static int
143 compare_sign(char *str1, char *str2)
144 {
145 	char *end = str1+SIGNLEN;
146 
147 	while (str1 != end) {
148 		if (*str1 != *str2) {
149 			return -1;
150 		}
151 		str1++;
152 		str2++;
153 	}
154 
155 	return 0;
156 }
157 
158 
159 /*
160  * Extract zero terminated short name from a directory entry.
161  */
162 static void get_name (dir_entry *dirent, char *s_name)
163 {
164 	char *ptr;
165 
166 	memcpy (s_name, dirent->name, 8);
167 	s_name[8] = '\0';
168 	ptr = s_name;
169 	while (*ptr && *ptr != ' ')
170 		ptr++;
171 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
172 		*ptr = '.';
173 		ptr++;
174 		memcpy (ptr, dirent->ext, 3);
175 		ptr[3] = '\0';
176 		while (*ptr && *ptr != ' ')
177 			ptr++;
178 	}
179 	*ptr = '\0';
180 	if (*s_name == DELETED_FLAG)
181 		*s_name = '\0';
182 	else if (*s_name == aRING)
183 		*s_name = '�';
184 	downcase (s_name);
185 }
186 
187 /*
188  * Get the entry at index 'entry' in a FAT (12/16/32) table.
189  * On failure 0x00 is returned.
190  */
191 static __u32
192 get_fatent(fsdata *mydata, __u32 entry)
193 {
194 	__u32 bufnum;
195 	__u32 offset;
196 	__u32 ret = 0x00;
197 
198 	switch (mydata->fatsize) {
199 	case 32:
200 		bufnum = entry / FAT32BUFSIZE;
201 		offset = entry - bufnum * FAT32BUFSIZE;
202 		break;
203 	case 16:
204 		bufnum = entry / FAT16BUFSIZE;
205 		offset = entry - bufnum * FAT16BUFSIZE;
206 		break;
207 	case 12:
208 		bufnum = entry / FAT12BUFSIZE;
209 		offset = entry - bufnum * FAT12BUFSIZE;
210 		break;
211 
212 	default:
213 		/* Unsupported FAT size */
214 		return ret;
215 	}
216 
217 	/* Read a new block of FAT entries into the cache. */
218 	if (bufnum != mydata->fatbufnum) {
219 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
220 		__u8 *bufptr = mydata->fatbuf;
221 		__u32 fatlength = mydata->fatlength;
222 		__u32 startblock = bufnum * FATBUFBLOCKS;
223 
224 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
225 		startblock += mydata->fat_sect;	/* Offset from start of disk */
226 
227 		if (getsize > fatlength) getsize = fatlength;
228 		if (disk_read(startblock, getsize, bufptr) < 0) {
229 			FAT_DPRINT("Error reading FAT blocks\n");
230 			return ret;
231 		}
232 		mydata->fatbufnum = bufnum;
233 	}
234 
235 	/* Get the actual entry from the table */
236 	switch (mydata->fatsize) {
237 	case 32:
238 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
239 		break;
240 	case 16:
241 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
242 		break;
243 	case 12: {
244 		__u32 off16 = (offset*3)/4;
245 		__u16 val1, val2;
246 
247 		switch (offset & 0x3) {
248 		case 0:
249 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
250 			ret &= 0xfff;
251 			break;
252 		case 1:
253 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
254 			val1 &= 0xf000;
255 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
256 			val2 &= 0x00ff;
257 			ret = (val2 << 4) | (val1 >> 12);
258 			break;
259 		case 2:
260 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
261 			val1 &= 0xff00;
262 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
263 			val2 &= 0x000f;
264 			ret = (val2 << 8) | (val1 >> 8);
265 			break;
266 		case 3:
267 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
268 			ret = (ret & 0xfff0) >> 4;
269 			break;
270 		default:
271 			break;
272 		}
273 	}
274 	break;
275 	}
276 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
277 
278 	return ret;
279 }
280 
281 
282 /*
283  * Read at most 'size' bytes from the specified cluster into 'buffer'.
284  * Return 0 on success, -1 otherwise.
285  */
286 static int
287 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
288 {
289 	int idx = 0;
290 	__u32 startsect;
291 
292 	if (clustnum > 0) {
293 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
294 	} else {
295 		startsect = mydata->rootdir_sect;
296 	}
297 
298 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
299 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
300 		FAT_DPRINT("Error reading data\n");
301 		return -1;
302 	}
303 	if(size % FS_BLOCK_SIZE) {
304 		__u8 tmpbuf[FS_BLOCK_SIZE];
305 		idx= size/FS_BLOCK_SIZE;
306 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
307 			FAT_DPRINT("Error reading data\n");
308 			return -1;
309 		}
310 		buffer += idx*FS_BLOCK_SIZE;
311 
312 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
313 		return 0;
314 	}
315 
316 	return 0;
317 }
318 
319 
320 /*
321  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
322  * into 'buffer'.
323  * Return the number of bytes read or -1 on fatal errors.
324  */
325 static long
326 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
327 	     unsigned long maxsize)
328 {
329 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
330 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
331 	__u32 curclust = START(dentptr);
332 	__u32 endclust, newclust;
333 	unsigned long actsize;
334 
335 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
336 
337 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
338 
339 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
340 
341 	actsize=bytesperclust;
342 	endclust=curclust;
343 	do {
344 		/* search for consecutive clusters */
345 		while(actsize < filesize) {
346 			newclust = get_fatent(mydata, endclust);
347 			if((newclust -1)!=endclust)
348 				goto getit;
349 			if (newclust <= 0x0001 || newclust >= 0xfff0) {
350 				FAT_DPRINT("curclust: 0x%x\n", newclust);
351 				FAT_DPRINT("Invalid FAT entry\n");
352 				return gotsize;
353 			}
354 			endclust=newclust;
355 			actsize+= bytesperclust;
356 		}
357 		/* actsize >= file size */
358 		actsize -= bytesperclust;
359 		/* get remaining clusters */
360 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
361 			FAT_ERROR("Error reading cluster\n");
362 			return -1;
363 		}
364 		/* get remaining bytes */
365 		gotsize += (int)actsize;
366 		filesize -= actsize;
367 		buffer += actsize;
368 		actsize= filesize;
369 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
370 			FAT_ERROR("Error reading cluster\n");
371 			return -1;
372 		}
373 		gotsize+=actsize;
374 		return gotsize;
375 getit:
376 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
377 			FAT_ERROR("Error reading cluster\n");
378 			return -1;
379 		}
380 		gotsize += (int)actsize;
381 		filesize -= actsize;
382 		buffer += actsize;
383 		curclust = get_fatent(mydata, endclust);
384 		if (curclust <= 0x0001 || curclust >= 0xfff0) {
385 			FAT_DPRINT("curclust: 0x%x\n", curclust);
386 			FAT_ERROR("Invalid FAT entry\n");
387 			return gotsize;
388 		}
389 		actsize=bytesperclust;
390 		endclust=curclust;
391 	} while (1);
392 }
393 
394 
395 #ifdef CONFIG_SUPPORT_VFAT
396 /*
397  * Extract the file name information from 'slotptr' into 'l_name',
398  * starting at l_name[*idx].
399  * Return 1 if terminator (zero byte) is found, 0 otherwise.
400  */
401 static int
402 slot2str(dir_slot *slotptr, char *l_name, int *idx)
403 {
404 	int j;
405 
406 	for (j = 0; j <= 8; j += 2) {
407 		l_name[*idx] = slotptr->name0_4[j];
408 		if (l_name[*idx] == 0x00) return 1;
409 		(*idx)++;
410 	}
411 	for (j = 0; j <= 10; j += 2) {
412 		l_name[*idx] = slotptr->name5_10[j];
413 		if (l_name[*idx] == 0x00) return 1;
414 		(*idx)++;
415 	}
416 	for (j = 0; j <= 2; j += 2) {
417 		l_name[*idx] = slotptr->name11_12[j];
418 		if (l_name[*idx] == 0x00) return 1;
419 		(*idx)++;
420 	}
421 
422 	return 0;
423 }
424 
425 
426 /*
427  * Extract the full long filename starting at 'retdent' (which is really
428  * a slot) into 'l_name'. If successful also copy the real directory entry
429  * into 'retdent'
430  * Return 0 on success, -1 otherwise.
431  */
432 static int
433 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
434 	     dir_entry *retdent, char *l_name)
435 {
436 	dir_entry *realdent;
437 	dir_slot  *slotptr = (dir_slot*) retdent;
438 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
439 	__u8	   counter = slotptr->id & 0xf;
440 	int idx = 0;
441 
442 	while ((__u8*)slotptr < nextclust) {
443 		if (counter == 0) break;
444 		if ((slotptr->id & 0x0f) != counter) return -1;
445 		slotptr++;
446 		counter--;
447 	}
448 
449 	if ((__u8*)slotptr >= nextclust) {
450 		__u8	 block[MAX_CLUSTSIZE];
451 		dir_slot *slotptr2;
452 
453 		slotptr--;
454 		curclust = get_fatent(mydata, curclust);
455 		if (curclust <= 0x0001 || curclust >= 0xfff0) {
456 			FAT_DPRINT("curclust: 0x%x\n", curclust);
457 			FAT_ERROR("Invalid FAT entry\n");
458 			return -1;
459 		}
460 		if (get_cluster(mydata, curclust, block,
461 				mydata->clust_size * SECTOR_SIZE) != 0) {
462 			FAT_DPRINT("Error: reading directory block\n");
463 			return -1;
464 		}
465 		slotptr2 = (dir_slot*) block;
466 		while (slotptr2->id > 0x01) {
467 			slotptr2++;
468 		}
469 		/* Save the real directory entry */
470 		realdent = (dir_entry*)slotptr2 + 1;
471 		while ((__u8*)slotptr2 >= block) {
472 			slot2str(slotptr2, l_name, &idx);
473 			slotptr2--;
474 		}
475 	} else {
476 		/* Save the real directory entry */
477 		realdent = (dir_entry*)slotptr;
478 	}
479 
480 	do {
481 		slotptr--;
482 		if (slot2str(slotptr, l_name, &idx)) break;
483 	} while (!(slotptr->id & 0x40));
484 
485 	l_name[idx] = '\0';
486 	if (*l_name == DELETED_FLAG) *l_name = '\0';
487 	else if (*l_name == aRING) *l_name = '�';
488 	downcase(l_name);
489 
490 	/* Return the real directory entry */
491 	memcpy(retdent, realdent, sizeof(dir_entry));
492 
493 	return 0;
494 }
495 
496 
497 /* Calculate short name checksum */
498 static __u8
499 mkcksum(const char *str)
500 {
501 	int i;
502 	__u8 ret = 0;
503 
504 	for (i = 0; i < 11; i++) {
505 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
506 	}
507 
508 	return ret;
509 }
510 #endif
511 
512 
513 /*
514  * Get the directory entry associated with 'filename' from the directory
515  * starting at 'startsect'
516  */
517 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
518 				   char *filename, dir_entry * retdent,
519 				   int dols)
520 {
521     __u16 prevcksum = 0xffff;
522     __u8 block[MAX_CLUSTSIZE];
523     __u32 curclust = START (retdent);
524     int files = 0, dirs = 0;
525 
526     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
527     while (1) {
528 	dir_entry *dentptr;
529 	int i;
530 
531 	if (get_cluster (mydata, curclust, block,
532 		 mydata->clust_size * SECTOR_SIZE) != 0) {
533 	    FAT_DPRINT ("Error: reading directory block\n");
534 	    return NULL;
535 	}
536 	dentptr = (dir_entry *) block;
537 	for (i = 0; i < DIRENTSPERCLUST; i++) {
538 	    char s_name[14], l_name[256];
539 
540 	    l_name[0] = '\0';
541 	    if ((dentptr->attr & ATTR_VOLUME)) {
542 #ifdef CONFIG_SUPPORT_VFAT
543 		if ((dentptr->attr & ATTR_VFAT) &&
544 		    (dentptr->name[0] & 0x40)) {
545 		    prevcksum = ((dir_slot *) dentptr)
546 			    ->alias_checksum;
547 		    get_vfatname (mydata, curclust, block,
548 				  dentptr, l_name);
549 		    if (dols) {
550 			int isdir = (dentptr->attr & ATTR_DIR);
551 			char dirc;
552 			int doit = 0;
553 
554 			if (isdir) {
555 			    dirs++;
556 			    dirc = '/';
557 			    doit = 1;
558 			} else {
559 			    dirc = ' ';
560 			    if (l_name[0] != 0) {
561 				files++;
562 				doit = 1;
563 			    }
564 			}
565 			if (doit) {
566 			    if (dirc == ' ') {
567 				printf (" %8ld   %s%c\n",
568 					(long) FAT2CPU32 (dentptr->size),
569 					l_name, dirc);
570 			    } else {
571 				printf ("            %s%c\n", l_name, dirc);
572 			    }
573 			}
574 			dentptr++;
575 			continue;
576 		    }
577 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
578 		} else
579 #endif
580 		{
581 		    /* Volume label or VFAT entry */
582 		    dentptr++;
583 		    continue;
584 		}
585 	    }
586 	    if (dentptr->name[0] == 0) {
587 		if (dols) {
588 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
589 		}
590 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
591 		return NULL;
592 	    }
593 #ifdef CONFIG_SUPPORT_VFAT
594 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
595 		dentptr++;
596 		continue;
597 	    }
598 #endif
599 	    get_name (dentptr, s_name);
600 	    if (dols) {
601 		int isdir = (dentptr->attr & ATTR_DIR);
602 		char dirc;
603 		int doit = 0;
604 
605 		if (isdir) {
606 		    dirs++;
607 		    dirc = '/';
608 		    doit = 1;
609 		} else {
610 		    dirc = ' ';
611 		    if (s_name[0] != 0) {
612 			files++;
613 			doit = 1;
614 		    }
615 		}
616 		if (doit) {
617 		    if (dirc == ' ') {
618 			printf (" %8ld   %s%c\n",
619 				(long) FAT2CPU32 (dentptr->size), s_name,
620 				dirc);
621 		    } else {
622 			printf ("            %s%c\n", s_name, dirc);
623 		    }
624 		}
625 		dentptr++;
626 		continue;
627 	    }
628 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
629 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
630 		dentptr++;
631 		continue;
632 	    }
633 	    memcpy (retdent, dentptr, sizeof (dir_entry));
634 
635 	    FAT_DPRINT ("DentName: %s", s_name);
636 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
637 	    FAT_DPRINT (", size:  0x%x %s\n",
638 			FAT2CPU32 (dentptr->size),
639 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
640 
641 	    return retdent;
642 	}
643 	curclust = get_fatent (mydata, curclust);
644 	if (curclust <= 0x0001 || curclust >= 0xfff0) {
645 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
646 	    FAT_ERROR ("Invalid FAT entry\n");
647 	    return NULL;
648 	}
649     }
650 
651     return NULL;
652 }
653 
654 
655 /*
656  * Read boot sector and volume info from a FAT filesystem
657  */
658 static int
659 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
660 {
661 	__u8 block[FS_BLOCK_SIZE];
662 	volume_info *vistart;
663 
664 	if (disk_read(0, 1, block) < 0) {
665 		FAT_DPRINT("Error: reading block\n");
666 		return -1;
667 	}
668 
669 	memcpy(bs, block, sizeof(boot_sector));
670 	bs->reserved	= FAT2CPU16(bs->reserved);
671 	bs->fat_length	= FAT2CPU16(bs->fat_length);
672 	bs->secs_track	= FAT2CPU16(bs->secs_track);
673 	bs->heads	= FAT2CPU16(bs->heads);
674 #if 0 /* UNUSED */
675 	bs->hidden	= FAT2CPU32(bs->hidden);
676 #endif
677 	bs->total_sect	= FAT2CPU32(bs->total_sect);
678 
679 	/* FAT32 entries */
680 	if (bs->fat_length == 0) {
681 		/* Assume FAT32 */
682 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
683 		bs->flags	 = FAT2CPU16(bs->flags);
684 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
685 		bs->info_sector  = FAT2CPU16(bs->info_sector);
686 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
687 		vistart = (volume_info*) (block + sizeof(boot_sector));
688 		*fatsize = 32;
689 	} else {
690 		vistart = (volume_info*) &(bs->fat32_length);
691 		*fatsize = 0;
692 	}
693 	memcpy(volinfo, vistart, sizeof(volume_info));
694 
695 	/* Terminate fs_type string. Writing past the end of vistart
696 	   is ok - it's just the buffer. */
697 	vistart->fs_type[8] = '\0';
698 
699 	if (*fatsize == 32) {
700 		if (compare_sign(FAT32_SIGN, vistart->fs_type) == 0) {
701 			return 0;
702 		}
703 	} else {
704 		if (compare_sign(FAT12_SIGN, vistart->fs_type) == 0) {
705 			*fatsize = 12;
706 			return 0;
707 		}
708 		if (compare_sign(FAT16_SIGN, vistart->fs_type) == 0) {
709 			*fatsize = 16;
710 			return 0;
711 		}
712 	}
713 
714 	FAT_DPRINT("Error: broken fs_type sign\n");
715 	return -1;
716 }
717 
718 
719 static long
720 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
721 	     int dols)
722 {
723     __u8 block[MAX_CLUSTSIZE];  /* Block buffer */
724     char fnamecopy[2048];
725     boot_sector bs;
726     volume_info volinfo;
727     fsdata datablock;
728     fsdata *mydata = &datablock;
729     dir_entry *dentptr;
730     __u16 prevcksum = 0xffff;
731     char *subname = "";
732     int rootdir_size, cursect;
733     int idx, isdir = 0;
734     int files = 0, dirs = 0;
735     long ret = 0;
736     int firsttime;
737 
738     if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
739 	FAT_DPRINT ("Error: reading boot sector\n");
740 	return -1;
741     }
742     if (mydata->fatsize == 32) {
743 	mydata->fatlength = bs.fat32_length;
744     } else {
745 	mydata->fatlength = bs.fat_length;
746     }
747     mydata->fat_sect = bs.reserved;
748     cursect = mydata->rootdir_sect
749 	    = mydata->fat_sect + mydata->fatlength * bs.fats;
750     mydata->clust_size = bs.cluster_size;
751     if (mydata->fatsize == 32) {
752 	rootdir_size = mydata->clust_size;
753 	mydata->data_begin = mydata->rootdir_sect   /* + rootdir_size */
754 		- (mydata->clust_size * 2);
755     } else {
756 	rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
757 			* sizeof (dir_entry)) / SECTOR_SIZE;
758 	mydata->data_begin = mydata->rootdir_sect + rootdir_size
759 		- (mydata->clust_size * 2);
760     }
761     mydata->fatbufnum = -1;
762 
763     FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
764 		mydata->fatlength);
765     FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
766 		"Data begins at: %d\n",
767 		mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
768 		rootdir_size, mydata->data_begin);
769     FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
770 
771     /* "cwd" is always the root... */
772     while (ISDIRDELIM (*filename))
773 	filename++;
774     /* Make a copy of the filename and convert it to lowercase */
775     strcpy (fnamecopy, filename);
776     downcase (fnamecopy);
777     if (*fnamecopy == '\0') {
778 	if (!dols)
779 	    return -1;
780 	dols = LS_ROOT;
781     } else if ((idx = dirdelim (fnamecopy)) >= 0) {
782 	isdir = 1;
783 	fnamecopy[idx] = '\0';
784 	subname = fnamecopy + idx + 1;
785 	/* Handle multiple delimiters */
786 	while (ISDIRDELIM (*subname))
787 	    subname++;
788     } else if (dols) {
789 	isdir = 1;
790     }
791 
792     while (1) {
793 	int i;
794 
795 	if (disk_read (cursect, mydata->clust_size, block) < 0) {
796 	    FAT_DPRINT ("Error: reading rootdir block\n");
797 	    return -1;
798 	}
799 	dentptr = (dir_entry *) block;
800 	for (i = 0; i < DIRENTSPERBLOCK; i++) {
801 	    char s_name[14], l_name[256];
802 
803 	    l_name[0] = '\0';
804 	    if ((dentptr->attr & ATTR_VOLUME)) {
805 #ifdef CONFIG_SUPPORT_VFAT
806 		if ((dentptr->attr & ATTR_VFAT) &&
807 		    (dentptr->name[0] & 0x40)) {
808 		    prevcksum = ((dir_slot *) dentptr)->alias_checksum;
809 		    get_vfatname (mydata, 0, block, dentptr, l_name);
810 		    if (dols == LS_ROOT) {
811 			int isdir = (dentptr->attr & ATTR_DIR);
812 			char dirc;
813 			int doit = 0;
814 
815 			if (isdir) {
816 			    dirs++;
817 			    dirc = '/';
818 			    doit = 1;
819 			} else {
820 			    dirc = ' ';
821 			    if (l_name[0] != 0) {
822 				files++;
823 				doit = 1;
824 			    }
825 			}
826 			if (doit) {
827 			    if (dirc == ' ') {
828 				printf (" %8ld   %s%c\n",
829 					(long) FAT2CPU32 (dentptr->size),
830 					l_name, dirc);
831 			    } else {
832 				printf ("            %s%c\n", l_name, dirc);
833 			    }
834 			}
835 			dentptr++;
836 			continue;
837 		    }
838 		    FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
839 		} else
840 #endif
841 		{
842 		    /* Volume label or VFAT entry */
843 		    dentptr++;
844 		    continue;
845 		}
846 	    } else if (dentptr->name[0] == 0) {
847 		FAT_DPRINT ("RootDentname == NULL - %d\n", i);
848 		if (dols == LS_ROOT) {
849 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
850 		    return 0;
851 		}
852 		return -1;
853 	    }
854 #ifdef CONFIG_SUPPORT_VFAT
855 	    else if (dols == LS_ROOT
856 		     && mkcksum (dentptr->name) == prevcksum) {
857 		dentptr++;
858 		continue;
859 	    }
860 #endif
861 	    get_name (dentptr, s_name);
862 	    if (dols == LS_ROOT) {
863 		int isdir = (dentptr->attr & ATTR_DIR);
864 		char dirc;
865 		int doit = 0;
866 
867 		if (isdir) {
868 		    dirc = '/';
869 		    if (s_name[0] != 0) {
870 			dirs++;
871 			doit = 1;
872 		    }
873 		} else {
874 		    dirc = ' ';
875 		    if (s_name[0] != 0) {
876 			files++;
877 			doit = 1;
878 		    }
879 		}
880 		if (doit) {
881 		    if (dirc == ' ') {
882 			printf (" %8ld   %s%c\n",
883 				(long) FAT2CPU32 (dentptr->size), s_name,
884 				dirc);
885 		    } else {
886 			printf ("            %s%c\n", s_name, dirc);
887 		    }
888 		}
889 		dentptr++;
890 		continue;
891 	    }
892 	    if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
893 		FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
894 		dentptr++;
895 		continue;
896 	    }
897 	    if (isdir && !(dentptr->attr & ATTR_DIR))
898 		return -1;
899 
900 	    FAT_DPRINT ("RootName: %s", s_name);
901 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
902 	    FAT_DPRINT (", size:  0x%x %s\n",
903 			FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
904 
905 	    goto rootdir_done;  /* We got a match */
906 	}
907 	cursect++;
908     }
909   rootdir_done:
910 
911     firsttime = 1;
912     while (isdir) {
913 	int startsect = mydata->data_begin
914 		+ START (dentptr) * mydata->clust_size;
915 	dir_entry dent;
916 	char *nextname = NULL;
917 
918 	dent = *dentptr;
919 	dentptr = &dent;
920 
921 	idx = dirdelim (subname);
922 	if (idx >= 0) {
923 	    subname[idx] = '\0';
924 	    nextname = subname + idx + 1;
925 	    /* Handle multiple delimiters */
926 	    while (ISDIRDELIM (*nextname))
927 		nextname++;
928 	    if (dols && *nextname == '\0')
929 		firsttime = 0;
930 	} else {
931 	    if (dols && firsttime) {
932 		firsttime = 0;
933 	    } else {
934 		isdir = 0;
935 	    }
936 	}
937 
938 	if (get_dentfromdir (mydata, startsect, subname, dentptr,
939 			     isdir ? 0 : dols) == NULL) {
940 	    if (dols && !isdir)
941 		return 0;
942 	    return -1;
943 	}
944 
945 	if (idx >= 0) {
946 	    if (!(dentptr->attr & ATTR_DIR))
947 		return -1;
948 	    subname = nextname;
949 	}
950     }
951     ret = get_contents (mydata, dentptr, buffer, maxsize);
952     FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
953 
954     return ret;
955 }
956 
957 
958 int
959 file_fat_detectfs(void)
960 {
961 	boot_sector	bs;
962 	volume_info	volinfo;
963 	int		fatsize;
964 	char	vol_label[12];
965 
966 	if(cur_dev==NULL) {
967 		printf("No current device\n");
968 		return 1;
969 	}
970 #if (CONFIG_COMMANDS & CFG_CMD_IDE) || (CONFIG_COMMANDS & CFG_CMD_SCSI)
971 	printf("Interface:  ");
972 	switch(cur_dev->if_type) {
973 		case IF_TYPE_IDE :	printf("IDE"); break;
974 		case IF_TYPE_SCSI :	printf("SCSI"); break;
975 		case IF_TYPE_ATAPI :	printf("ATAPI"); break;
976 		case IF_TYPE_USB :	printf("USB"); break;
977 		case IF_TYPE_DOC :	printf("DOC"); break;
978 		case IF_TYPE_MMC :	printf("MMC"); break;
979 		default :		printf("Unknown");
980 	}
981 	printf("\n  Device %d: ",cur_dev->dev);
982 	dev_print(cur_dev);
983 #endif
984 	if(read_bootsectandvi(&bs, &volinfo, &fatsize)) {
985 		printf("\nNo valid FAT fs found\n");
986 		return 1;
987 	}
988 	memcpy (vol_label, volinfo.volume_label, 11);
989 	vol_label[11] = '\0';
990 	volinfo.fs_type[5]='\0';
991 	printf("Partition %d: Filesystem: %s \"%s\"\n",cur_part,volinfo.fs_type,vol_label);
992 	return 0;
993 }
994 
995 
996 int
997 file_fat_ls(const char *dir)
998 {
999 	return do_fat_read(dir, NULL, 0, LS_YES);
1000 }
1001 
1002 
1003 long
1004 file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1005 {
1006 	printf("reading %s\n",filename);
1007 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1008 }
1009 
1010 #endif /* #if (CONFIG_COMMANDS & CFG_CMD_FAT) */
1011