xref: /rk3399_rockchip-uboot/fs/fat/fat.c (revision 0c852a2886fb51222f8fb07e6cde3b72fa4e566d)
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 /*
37  * Convert a string to lowercase.
38  */
39 static void
40 downcase(char *str)
41 {
42 	while (*str != '\0') {
43 		TOLOWER(*str);
44 		str++;
45 	}
46 }
47 
48 static  block_dev_desc_t *cur_dev = NULL;
49 static unsigned long part_offset = 0;
50 static int cur_part = 1;
51 
52 #define DOS_PART_TBL_OFFSET	0x1be
53 #define DOS_PART_MAGIC_OFFSET	0x1fe
54 #define DOS_FS_TYPE_OFFSET	0x36
55 
56 int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
57 {
58 	startblock += part_offset;
59 	if (cur_dev == NULL)
60 		return -1;
61 	if (cur_dev->block_read) {
62 		return cur_dev->block_read (cur_dev->dev, startblock, getsize, (unsigned long *)bufptr);
63 	}
64 	return -1;
65 }
66 
67 
68 int
69 fat_register_device(block_dev_desc_t *dev_desc, int part_no)
70 {
71 	unsigned char buffer[SECTOR_SIZE];
72 
73 	if (!dev_desc->block_read)
74 		return -1;
75 	cur_dev=dev_desc;
76 	/* check if we have a MBR (on floppies we have only a PBR) */
77 	if (dev_desc->block_read (dev_desc->dev, 0, 1, (ulong *) buffer) != 1) {
78 		printf ("** Can't read from device %d **\n", dev_desc->dev);
79 		return -1;
80 	}
81 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
82 		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
83 		/* no signature found */
84 		return -1;
85 	}
86 	if(!strncmp(&buffer[DOS_FS_TYPE_OFFSET],"FAT",3)) {
87 		/* ok, we assume we are on a PBR only */
88 		cur_part = 1;
89 		part_offset=0;
90 	}
91 	else {
92 #if (CONFIG_COMMANDS & CFG_CMD_IDE) || (CONFIG_COMMANDS & CFG_CMD_SCSI)
93 		disk_partition_t info;
94 		if(!get_partition_info(dev_desc, part_no, &info)) {
95 			part_offset = info.start;
96 			cur_part = part_no;
97 		}
98 		else {
99 			printf ("** Partition %d not valid on device %d **\n",part_no,dev_desc->dev);
100 			return -1;
101 		}
102 #else
103 		/* FIXME we need to determine the start block of the
104 		 * partition where the DOS FS resides. This can be done
105 		 * by using the get_partition_info routine. For this
106 		 * purpose the libpart must be included.
107 		 */
108 		part_offset=32;
109 		cur_part = 1;
110 #endif
111 	}
112 	return 0;
113 }
114 
115 
116 /*
117  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
118  * Return index into string if found, -1 otherwise.
119  */
120 static int
121 dirdelim(char *str)
122 {
123 	char *start = str;
124 
125 	while (*str != '\0') {
126 		if (ISDIRDELIM(*str)) return str - start;
127 		str++;
128 	}
129 	return -1;
130 }
131 
132 
133 /*
134  * Match volume_info fs_type strings.
135  * Return 0 on match, -1 otherwise.
136  */
137 static int
138 compare_sign(char *str1, char *str2)
139 {
140 	char *end = str1+SIGNLEN;
141 
142 	while (str1 != end) {
143 		if (*str1 != *str2) {
144 			return -1;
145 		}
146 		str1++;
147 		str2++;
148 	}
149 
150 	return 0;
151 }
152 
153 
154 /*
155  * Extract zero terminated short name from a directory entry.
156  */
157 static void get_name (dir_entry *dirent, char *s_name)
158 {
159 	char *ptr;
160 
161 	memcpy (s_name, dirent->name, 8);
162 	s_name[8] = '\0';
163 	ptr = s_name;
164 	while (*ptr && *ptr != ' ')
165 		ptr++;
166 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
167 		*ptr = '.';
168 		ptr++;
169 		memcpy (ptr, dirent->ext, 3);
170 		ptr[3] = '\0';
171 		while (*ptr && *ptr != ' ')
172 			ptr++;
173 	}
174 	*ptr = '\0';
175 	if (*s_name == DELETED_FLAG)
176 		*s_name = '\0';
177 	else if (*s_name == aRING)
178 		*s_name = '�';
179 	downcase (s_name);
180 }
181 
182 /*
183  * Get the entry at index 'entry' in a FAT (12/16/32) table.
184  * On failure 0x00 is returned.
185  */
186 static __u32
187 get_fatent(fsdata *mydata, __u32 entry)
188 {
189 	__u32 bufnum;
190 	__u32 offset;
191 	__u32 ret = 0x00;
192 
193 	switch (mydata->fatsize) {
194 	case 32:
195 		bufnum = entry / FAT32BUFSIZE;
196 		offset = entry - bufnum * FAT32BUFSIZE;
197 		break;
198 	case 16:
199 		bufnum = entry / FAT16BUFSIZE;
200 		offset = entry - bufnum * FAT16BUFSIZE;
201 		break;
202 	case 12:
203 		bufnum = entry / FAT12BUFSIZE;
204 		offset = entry - bufnum * FAT12BUFSIZE;
205 		break;
206 
207 	default:
208 		/* Unsupported FAT size */
209 		return ret;
210 	}
211 
212 	/* Read a new block of FAT entries into the cache. */
213 	if (bufnum != mydata->fatbufnum) {
214 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
215 		__u8 *bufptr = mydata->fatbuf;
216 		__u32 fatlength = mydata->fatlength;
217 		__u32 startblock = bufnum * FATBUFBLOCKS;
218 
219 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
220 		startblock += mydata->fat_sect;	/* Offset from start of disk */
221 
222 		if (getsize > fatlength) getsize = fatlength;
223 		if (disk_read(startblock, getsize, bufptr) < 0) {
224 			FAT_DPRINT("Error reading FAT blocks\n");
225 			return ret;
226 		}
227 		mydata->fatbufnum = bufnum;
228 	}
229 
230 	/* Get the actual entry from the table */
231 	switch (mydata->fatsize) {
232 	case 32:
233 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
234 		break;
235 	case 16:
236 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
237 		break;
238 	case 12: {
239 		__u32 off16 = (offset*3)/4;
240 		__u16 val1, val2;
241 
242 		switch (offset & 0x3) {
243 		case 0:
244 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
245 			ret &= 0xfff;
246 			break;
247 		case 1:
248 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
249 			val1 &= 0xf000;
250 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
251 			val2 &= 0x00ff;
252 			ret = (val2 << 4) | (val1 >> 12);
253 			break;
254 		case 2:
255 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
256 			val1 &= 0xff00;
257 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
258 			val2 &= 0x000f;
259 			ret = (val2 << 8) | (val1 >> 8);
260 			break;
261 		case 3:
262 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
263 			ret = (ret & 0xfff0) >> 4;
264 			break;
265 		default:
266 			break;
267 		}
268 	}
269 	break;
270 	}
271 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
272 
273 	return ret;
274 }
275 
276 
277 /*
278  * Read at most 'size' bytes from the specified cluster into 'buffer'.
279  * Return 0 on success, -1 otherwise.
280  */
281 static int
282 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
283 {
284 	int idx = 0;
285 	__u32 startsect;
286 
287 	if (clustnum > 0) {
288 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
289 	} else {
290 		startsect = mydata->rootdir_sect;
291 	}
292 
293 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
294 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
295 		FAT_DPRINT("Error reading data\n");
296 		return -1;
297 	}
298 	if(size % FS_BLOCK_SIZE) {
299 		__u8 tmpbuf[FS_BLOCK_SIZE];
300 		idx= size/FS_BLOCK_SIZE;
301 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
302 			FAT_DPRINT("Error reading data\n");
303 			return -1;
304 		}
305 		buffer += idx*FS_BLOCK_SIZE;
306 
307 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
308 		return 0;
309 	}
310 
311 	return 0;
312 }
313 
314 
315 /*
316  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
317  * into 'buffer'.
318  * Return the number of bytes read or -1 on fatal errors.
319  */
320 static long
321 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
322 	     unsigned long maxsize)
323 {
324 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
325 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
326 	__u32 curclust = START(dentptr);
327 	__u32 endclust, newclust;
328 	unsigned long actsize;
329 
330 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
331 
332 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
333 
334 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
335 
336 	actsize=bytesperclust;
337 	endclust=curclust;
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 (newclust <= 0x0001 || newclust >= 0xfff0) {
345 				FAT_DPRINT("curclust: 0x%x\n", newclust);
346 				FAT_DPRINT("Invalid FAT entry\n");
347 				return gotsize;
348 			}
349 			endclust=newclust;
350 			actsize+= bytesperclust;
351 		}
352 		/* actsize >= file size */
353 		actsize -= bytesperclust;
354 		/* get remaining clusters */
355 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
356 			FAT_ERROR("Error reading cluster\n");
357 			return -1;
358 		}
359 		/* get remaining bytes */
360 		gotsize += (int)actsize;
361 		filesize -= actsize;
362 		buffer += actsize;
363 		actsize= filesize;
364 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
365 			FAT_ERROR("Error reading cluster\n");
366 			return -1;
367 		}
368 		gotsize+=actsize;
369 		return gotsize;
370 getit:
371 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
372 			FAT_ERROR("Error reading cluster\n");
373 			return -1;
374 		}
375 		gotsize += (int)actsize;
376 		filesize -= actsize;
377 		buffer += actsize;
378 		curclust = get_fatent(mydata, endclust);
379 		if (curclust <= 0x0001 || curclust >= 0xfff0) {
380 			FAT_DPRINT("curclust: 0x%x\n", curclust);
381 			FAT_ERROR("Invalid FAT entry\n");
382 			return gotsize;
383 		}
384 		actsize=bytesperclust;
385 		endclust=curclust;
386 	} while (1);
387 }
388 
389 
390 #ifdef CONFIG_SUPPORT_VFAT
391 /*
392  * Extract the file name information from 'slotptr' into 'l_name',
393  * starting at l_name[*idx].
394  * Return 1 if terminator (zero byte) is found, 0 otherwise.
395  */
396 static int
397 slot2str(dir_slot *slotptr, char *l_name, int *idx)
398 {
399 	int j;
400 
401 	for (j = 0; j <= 8; j += 2) {
402 		l_name[*idx] = slotptr->name0_4[j];
403 		if (l_name[*idx] == 0x00) return 1;
404 		(*idx)++;
405 	}
406 	for (j = 0; j <= 10; j += 2) {
407 		l_name[*idx] = slotptr->name5_10[j];
408 		if (l_name[*idx] == 0x00) return 1;
409 		(*idx)++;
410 	}
411 	for (j = 0; j <= 2; j += 2) {
412 		l_name[*idx] = slotptr->name11_12[j];
413 		if (l_name[*idx] == 0x00) return 1;
414 		(*idx)++;
415 	}
416 
417 	return 0;
418 }
419 
420 
421 /*
422  * Extract the full long filename starting at 'retdent' (which is really
423  * a slot) into 'l_name'. If successful also copy the real directory entry
424  * into 'retdent'
425  * Return 0 on success, -1 otherwise.
426  */
427 __u8	 get_vfatname_block[MAX_CLUSTSIZE];
428 static int
429 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
430 	     dir_entry *retdent, char *l_name)
431 {
432 	dir_entry *realdent;
433 	dir_slot  *slotptr = (dir_slot*) retdent;
434 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
435 	__u8	   counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
436 	int idx = 0;
437 
438 	while ((__u8*)slotptr < nextclust) {
439 		if (counter == 0) break;
440 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
441 			return -1;
442 		slotptr++;
443 		counter--;
444 	}
445 
446 	if ((__u8*)slotptr >= nextclust) {
447 		dir_slot *slotptr2;
448 
449 		slotptr--;
450 		curclust = get_fatent(mydata, curclust);
451 		if (curclust <= 0x0001 || curclust >= 0xfff0) {
452 			FAT_DPRINT("curclust: 0x%x\n", curclust);
453 			FAT_ERROR("Invalid FAT entry\n");
454 			return -1;
455 		}
456 		if (get_cluster(mydata, curclust, get_vfatname_block,
457 				mydata->clust_size * SECTOR_SIZE) != 0) {
458 			FAT_DPRINT("Error: reading directory block\n");
459 			return -1;
460 		}
461 		slotptr2 = (dir_slot*) get_vfatname_block;
462 		while (slotptr2->id > 0x01) {
463 			slotptr2++;
464 		}
465 		/* Save the real directory entry */
466 		realdent = (dir_entry*)slotptr2 + 1;
467 		while ((__u8*)slotptr2 >= get_vfatname_block) {
468 			slot2str(slotptr2, l_name, &idx);
469 			slotptr2--;
470 		}
471 	} else {
472 		/* Save the real directory entry */
473 		realdent = (dir_entry*)slotptr;
474 	}
475 
476 	do {
477 		slotptr--;
478 		if (slot2str(slotptr, l_name, &idx)) break;
479 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
480 
481 	l_name[idx] = '\0';
482 	if (*l_name == DELETED_FLAG) *l_name = '\0';
483 	else if (*l_name == aRING) *l_name = '�';
484 	downcase(l_name);
485 
486 	/* Return the real directory entry */
487 	memcpy(retdent, realdent, sizeof(dir_entry));
488 
489 	return 0;
490 }
491 
492 
493 /* Calculate short name checksum */
494 static __u8
495 mkcksum(const char *str)
496 {
497 	int i;
498 	__u8 ret = 0;
499 
500 	for (i = 0; i < 11; i++) {
501 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
502 	}
503 
504 	return ret;
505 }
506 #endif
507 
508 
509 /*
510  * Get the directory entry associated with 'filename' from the directory
511  * starting at 'startsect'
512  */
513 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
514 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
515 				   char *filename, dir_entry * retdent,
516 				   int dols)
517 {
518     __u16 prevcksum = 0xffff;
519     __u32 curclust = START (retdent);
520     int files = 0, dirs = 0;
521 
522     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
523     while (1) {
524 	dir_entry *dentptr;
525 	int i;
526 
527 	if (get_cluster (mydata, curclust, get_dentfromdir_block,
528 		 mydata->clust_size * SECTOR_SIZE) != 0) {
529 	    FAT_DPRINT ("Error: reading directory block\n");
530 	    return NULL;
531 	}
532 	dentptr = (dir_entry *) get_dentfromdir_block;
533 	for (i = 0; i < DIRENTSPERCLUST; i++) {
534 	    char s_name[14], l_name[256];
535 
536 	    l_name[0] = '\0';
537 	    if ((dentptr->attr & ATTR_VOLUME)) {
538 #ifdef CONFIG_SUPPORT_VFAT
539 		if ((dentptr->attr & ATTR_VFAT) &&
540 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
541 		    prevcksum = ((dir_slot *) dentptr)
542 			    ->alias_checksum;
543 		    get_vfatname (mydata, curclust, get_dentfromdir_block,
544 				  dentptr, l_name);
545 		    if (dols) {
546 			int isdir = (dentptr->attr & ATTR_DIR);
547 			char dirc;
548 			int doit = 0;
549 
550 			if (isdir) {
551 			    dirs++;
552 			    dirc = '/';
553 			    doit = 1;
554 			} else {
555 			    dirc = ' ';
556 			    if (l_name[0] != 0) {
557 				files++;
558 				doit = 1;
559 			    }
560 			}
561 			if (doit) {
562 			    if (dirc == ' ') {
563 				printf (" %8ld   %s%c\n",
564 					(long) FAT2CPU32 (dentptr->size),
565 					l_name, dirc);
566 			    } else {
567 				printf ("            %s%c\n", l_name, dirc);
568 			    }
569 			}
570 			dentptr++;
571 			continue;
572 		    }
573 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
574 		} else
575 #endif
576 		{
577 		    /* Volume label or VFAT entry */
578 		    dentptr++;
579 		    continue;
580 		}
581 	    }
582 	    if (dentptr->name[0] == 0) {
583 		if (dols) {
584 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
585 		}
586 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
587 		return NULL;
588 	    }
589 #ifdef CONFIG_SUPPORT_VFAT
590 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
591 		dentptr++;
592 		continue;
593 	    }
594 #endif
595 	    get_name (dentptr, s_name);
596 	    if (dols) {
597 		int isdir = (dentptr->attr & ATTR_DIR);
598 		char dirc;
599 		int doit = 0;
600 
601 		if (isdir) {
602 		    dirs++;
603 		    dirc = '/';
604 		    doit = 1;
605 		} else {
606 		    dirc = ' ';
607 		    if (s_name[0] != 0) {
608 			files++;
609 			doit = 1;
610 		    }
611 		}
612 		if (doit) {
613 		    if (dirc == ' ') {
614 			printf (" %8ld   %s%c\n",
615 				(long) FAT2CPU32 (dentptr->size), s_name,
616 				dirc);
617 		    } else {
618 			printf ("            %s%c\n", s_name, dirc);
619 		    }
620 		}
621 		dentptr++;
622 		continue;
623 	    }
624 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
625 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
626 		dentptr++;
627 		continue;
628 	    }
629 	    memcpy (retdent, dentptr, sizeof (dir_entry));
630 
631 	    FAT_DPRINT ("DentName: %s", s_name);
632 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
633 	    FAT_DPRINT (", size:  0x%x %s\n",
634 			FAT2CPU32 (dentptr->size),
635 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
636 
637 	    return retdent;
638 	}
639 	curclust = get_fatent (mydata, curclust);
640 	if (curclust <= 0x0001 || curclust >= 0xfff0) {
641 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
642 	    FAT_ERROR ("Invalid FAT entry\n");
643 	    return NULL;
644 	}
645     }
646 
647     return NULL;
648 }
649 
650 
651 /*
652  * Read boot sector and volume info from a FAT filesystem
653  */
654 static int
655 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
656 {
657 	__u8 block[FS_BLOCK_SIZE];
658 	volume_info *vistart;
659 
660 	if (disk_read(0, 1, block) < 0) {
661 		FAT_DPRINT("Error: reading block\n");
662 		return -1;
663 	}
664 
665 	memcpy(bs, block, sizeof(boot_sector));
666 	bs->reserved	= FAT2CPU16(bs->reserved);
667 	bs->fat_length	= FAT2CPU16(bs->fat_length);
668 	bs->secs_track	= FAT2CPU16(bs->secs_track);
669 	bs->heads	= FAT2CPU16(bs->heads);
670 #if 0 /* UNUSED */
671 	bs->hidden	= FAT2CPU32(bs->hidden);
672 #endif
673 	bs->total_sect	= FAT2CPU32(bs->total_sect);
674 
675 	/* FAT32 entries */
676 	if (bs->fat_length == 0) {
677 		/* Assume FAT32 */
678 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
679 		bs->flags	 = FAT2CPU16(bs->flags);
680 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
681 		bs->info_sector  = FAT2CPU16(bs->info_sector);
682 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
683 		vistart = (volume_info*) (block + sizeof(boot_sector));
684 		*fatsize = 32;
685 	} else {
686 		vistart = (volume_info*) &(bs->fat32_length);
687 		*fatsize = 0;
688 	}
689 	memcpy(volinfo, vistart, sizeof(volume_info));
690 
691 	/* Terminate fs_type string. Writing past the end of vistart
692 	   is ok - it's just the buffer. */
693 	vistart->fs_type[8] = '\0';
694 
695 	if (*fatsize == 32) {
696 		if (compare_sign(FAT32_SIGN, vistart->fs_type) == 0) {
697 			return 0;
698 		}
699 	} else {
700 		if (compare_sign(FAT12_SIGN, vistart->fs_type) == 0) {
701 			*fatsize = 12;
702 			return 0;
703 		}
704 		if (compare_sign(FAT16_SIGN, vistart->fs_type) == 0) {
705 			*fatsize = 16;
706 			return 0;
707 		}
708 	}
709 
710 	FAT_DPRINT("Error: broken fs_type sign\n");
711 	return -1;
712 }
713 
714 
715 __u8 do_fat_read_block[MAX_CLUSTSIZE];  /* Block buffer */
716 static long
717 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
718 	     int dols)
719 {
720     char fnamecopy[2048];
721     boot_sector bs;
722     volume_info volinfo;
723     fsdata datablock;
724     fsdata *mydata = &datablock;
725     dir_entry *dentptr;
726     __u16 prevcksum = 0xffff;
727     char *subname = "";
728     int rootdir_size, cursect;
729     int idx, isdir = 0;
730     int files = 0, dirs = 0;
731     long ret = 0;
732     int firsttime;
733 
734     if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
735 	FAT_DPRINT ("Error: reading boot sector\n");
736 	return -1;
737     }
738     if (mydata->fatsize == 32) {
739 	mydata->fatlength = bs.fat32_length;
740     } else {
741 	mydata->fatlength = bs.fat_length;
742     }
743     mydata->fat_sect = bs.reserved;
744     cursect = mydata->rootdir_sect
745 	    = mydata->fat_sect + mydata->fatlength * bs.fats;
746     mydata->clust_size = bs.cluster_size;
747     if (mydata->fatsize == 32) {
748 	rootdir_size = mydata->clust_size;
749 	mydata->data_begin = mydata->rootdir_sect   /* + rootdir_size */
750 		- (mydata->clust_size * 2);
751     } else {
752 	rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
753 			* sizeof (dir_entry)) / SECTOR_SIZE;
754 	mydata->data_begin = mydata->rootdir_sect + rootdir_size
755 		- (mydata->clust_size * 2);
756     }
757     mydata->fatbufnum = -1;
758 
759     FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
760 		mydata->fatlength);
761     FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
762 		"Data begins at: %d\n",
763 		mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
764 		rootdir_size, mydata->data_begin);
765     FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
766 
767     /* "cwd" is always the root... */
768     while (ISDIRDELIM (*filename))
769 	filename++;
770     /* Make a copy of the filename and convert it to lowercase */
771     strcpy (fnamecopy, filename);
772     downcase (fnamecopy);
773     if (*fnamecopy == '\0') {
774 	if (!dols)
775 	    return -1;
776 	dols = LS_ROOT;
777     } else if ((idx = dirdelim (fnamecopy)) >= 0) {
778 	isdir = 1;
779 	fnamecopy[idx] = '\0';
780 	subname = fnamecopy + idx + 1;
781 	/* Handle multiple delimiters */
782 	while (ISDIRDELIM (*subname))
783 	    subname++;
784     } else if (dols) {
785 	isdir = 1;
786     }
787 
788     while (1) {
789 	int i;
790 
791 	if (disk_read (cursect, mydata->clust_size, do_fat_read_block) < 0) {
792 	    FAT_DPRINT ("Error: reading rootdir block\n");
793 	    return -1;
794 	}
795 	dentptr = (dir_entry *) do_fat_read_block;
796 	for (i = 0; i < DIRENTSPERBLOCK; i++) {
797 	    char s_name[14], l_name[256];
798 
799 	    l_name[0] = '\0';
800 	    if ((dentptr->attr & ATTR_VOLUME)) {
801 #ifdef CONFIG_SUPPORT_VFAT
802 		if ((dentptr->attr & ATTR_VFAT) &&
803 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
804 		    prevcksum = ((dir_slot *) dentptr)->alias_checksum;
805 		    get_vfatname (mydata, 0, do_fat_read_block, dentptr, l_name);
806 		    if (dols == LS_ROOT) {
807 			int isdir = (dentptr->attr & ATTR_DIR);
808 			char dirc;
809 			int doit = 0;
810 
811 			if (isdir) {
812 			    dirs++;
813 			    dirc = '/';
814 			    doit = 1;
815 			} else {
816 			    dirc = ' ';
817 			    if (l_name[0] != 0) {
818 				files++;
819 				doit = 1;
820 			    }
821 			}
822 			if (doit) {
823 			    if (dirc == ' ') {
824 				printf (" %8ld   %s%c\n",
825 					(long) FAT2CPU32 (dentptr->size),
826 					l_name, dirc);
827 			    } else {
828 				printf ("            %s%c\n", l_name, dirc);
829 			    }
830 			}
831 			dentptr++;
832 			continue;
833 		    }
834 		    FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
835 		} else
836 #endif
837 		{
838 		    /* Volume label or VFAT entry */
839 		    dentptr++;
840 		    continue;
841 		}
842 	    } else if (dentptr->name[0] == 0) {
843 		FAT_DPRINT ("RootDentname == NULL - %d\n", i);
844 		if (dols == LS_ROOT) {
845 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
846 		    return 0;
847 		}
848 		return -1;
849 	    }
850 #ifdef CONFIG_SUPPORT_VFAT
851 	    else if (dols == LS_ROOT
852 		     && mkcksum (dentptr->name) == prevcksum) {
853 		dentptr++;
854 		continue;
855 	    }
856 #endif
857 	    get_name (dentptr, s_name);
858 	    if (dols == LS_ROOT) {
859 		int isdir = (dentptr->attr & ATTR_DIR);
860 		char dirc;
861 		int doit = 0;
862 
863 		if (isdir) {
864 		    dirc = '/';
865 		    if (s_name[0] != 0) {
866 			dirs++;
867 			doit = 1;
868 		    }
869 		} else {
870 		    dirc = ' ';
871 		    if (s_name[0] != 0) {
872 			files++;
873 			doit = 1;
874 		    }
875 		}
876 		if (doit) {
877 		    if (dirc == ' ') {
878 			printf (" %8ld   %s%c\n",
879 				(long) FAT2CPU32 (dentptr->size), s_name,
880 				dirc);
881 		    } else {
882 			printf ("            %s%c\n", s_name, dirc);
883 		    }
884 		}
885 		dentptr++;
886 		continue;
887 	    }
888 	    if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
889 		FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
890 		dentptr++;
891 		continue;
892 	    }
893 	    if (isdir && !(dentptr->attr & ATTR_DIR))
894 		return -1;
895 
896 	    FAT_DPRINT ("RootName: %s", s_name);
897 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
898 	    FAT_DPRINT (", size:  0x%x %s\n",
899 			FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
900 
901 	    goto rootdir_done;  /* We got a match */
902 	}
903 	cursect++;
904     }
905   rootdir_done:
906 
907     firsttime = 1;
908     while (isdir) {
909 	int startsect = mydata->data_begin
910 		+ START (dentptr) * mydata->clust_size;
911 	dir_entry dent;
912 	char *nextname = NULL;
913 
914 	dent = *dentptr;
915 	dentptr = &dent;
916 
917 	idx = dirdelim (subname);
918 	if (idx >= 0) {
919 	    subname[idx] = '\0';
920 	    nextname = subname + idx + 1;
921 	    /* Handle multiple delimiters */
922 	    while (ISDIRDELIM (*nextname))
923 		nextname++;
924 	    if (dols && *nextname == '\0')
925 		firsttime = 0;
926 	} else {
927 	    if (dols && firsttime) {
928 		firsttime = 0;
929 	    } else {
930 		isdir = 0;
931 	    }
932 	}
933 
934 	if (get_dentfromdir (mydata, startsect, subname, dentptr,
935 			     isdir ? 0 : dols) == NULL) {
936 	    if (dols && !isdir)
937 		return 0;
938 	    return -1;
939 	}
940 
941 	if (idx >= 0) {
942 	    if (!(dentptr->attr & ATTR_DIR))
943 		return -1;
944 	    subname = nextname;
945 	}
946     }
947     ret = get_contents (mydata, dentptr, buffer, maxsize);
948     FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
949 
950     return ret;
951 }
952 
953 
954 int
955 file_fat_detectfs(void)
956 {
957 	boot_sector	bs;
958 	volume_info	volinfo;
959 	int		fatsize;
960 	char	vol_label[12];
961 
962 	if(cur_dev==NULL) {
963 		printf("No current device\n");
964 		return 1;
965 	}
966 #if (CONFIG_COMMANDS & CFG_CMD_IDE) || (CONFIG_COMMANDS & CFG_CMD_SCSI) || \
967     (CONFIG_COMMANDS & CFG_CMD_USB) || (CONFIG_MMC)
968 	printf("Interface:  ");
969 	switch(cur_dev->if_type) {
970 		case IF_TYPE_IDE :	printf("IDE"); break;
971 		case IF_TYPE_SCSI :	printf("SCSI"); break;
972 		case IF_TYPE_ATAPI :	printf("ATAPI"); break;
973 		case IF_TYPE_USB :	printf("USB"); break;
974 		case IF_TYPE_DOC :	printf("DOC"); break;
975 		case IF_TYPE_MMC :	printf("MMC"); break;
976 		default :		printf("Unknown");
977 	}
978 	printf("\n  Device %d: ",cur_dev->dev);
979 	dev_print(cur_dev);
980 #endif
981 	if(read_bootsectandvi(&bs, &volinfo, &fatsize)) {
982 		printf("\nNo valid FAT fs found\n");
983 		return 1;
984 	}
985 	memcpy (vol_label, volinfo.volume_label, 11);
986 	vol_label[11] = '\0';
987 	volinfo.fs_type[5]='\0';
988 	printf("Partition %d: Filesystem: %s \"%s\"\n",cur_part,volinfo.fs_type,vol_label);
989 	return 0;
990 }
991 
992 
993 int
994 file_fat_ls(const char *dir)
995 {
996 	return do_fat_read(dir, NULL, 0, LS_YES);
997 }
998 
999 
1000 long
1001 file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1002 {
1003 	printf("reading %s\n",filename);
1004 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1005 }
1006 
1007 #endif /* #if (CONFIG_COMMANDS & CFG_CMD_FAT) */
1008