xref: /openbmc/u-boot/fs/fat/fat.c (revision 08ab4e17)
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 /*
35  * Convert a string to lowercase.
36  */
37 static void
38 downcase(char *str)
39 {
40 	while (*str != '\0') {
41 		TOLOWER(*str);
42 		str++;
43 	}
44 }
45 
46 static  block_dev_desc_t *cur_dev = NULL;
47 static unsigned long part_offset = 0;
48 static int cur_part = 1;
49 
50 #define DOS_PART_TBL_OFFSET	0x1be
51 #define DOS_PART_MAGIC_OFFSET	0x1fe
52 #define DOS_FS_TYPE_OFFSET	0x36
53 
54 int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
55 {
56 	startblock += part_offset;
57 	if (cur_dev == NULL)
58 		return -1;
59 	if (cur_dev->block_read) {
60 		return cur_dev->block_read (cur_dev->dev
61 			, startblock, getsize, (unsigned long *)bufptr);
62 	}
63 	return -1;
64 }
65 
66 
67 int
68 fat_register_device(block_dev_desc_t *dev_desc, int part_no)
69 {
70 	unsigned char buffer[SECTOR_SIZE];
71 	disk_partition_t info;
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 (defined(CONFIG_CMD_IDE) || \
87      defined(CONFIG_CMD_SCSI) || \
88      defined(CONFIG_CMD_USB) || \
89      defined(CONFIG_MMC) || \
90      defined(CONFIG_SYSTEMACE) )
91 	/* First we assume, there is a MBR */
92 	if (!get_partition_info (dev_desc, part_no, &info)) {
93 		part_offset = info.start;
94 		cur_part = part_no;
95 	} else if (!strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3)) {
96 		/* ok, we assume we are on a PBR only */
97 		cur_part = 1;
98 		part_offset = 0;
99 	} else {
100 		printf ("** Partition %d not valid on device %d **\n",
101 				part_no, dev_desc->dev);
102 		return -1;
103 	}
104 
105 #else
106 	if (!strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET],"FAT",3)) {
107 		/* ok, we assume we are on a PBR only */
108 		cur_part = 1;
109 		part_offset = 0;
110 		info.start = part_offset;
111 	} else {
112 		/* FIXME we need to determine the start block of the
113 		 * partition where the DOS FS resides. This can be done
114 		 * by using the get_partition_info routine. For this
115 		 * purpose the libpart must be included.
116 		 */
117 		part_offset = 32;
118 		cur_part = 1;
119 	}
120 #endif
121 	return 0;
122 }
123 
124 
125 /*
126  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
127  * Return index into string if found, -1 otherwise.
128  */
129 static int
130 dirdelim(char *str)
131 {
132 	char *start = str;
133 
134 	while (*str != '\0') {
135 		if (ISDIRDELIM(*str)) return str - start;
136 		str++;
137 	}
138 	return -1;
139 }
140 
141 
142 /*
143  * Match volume_info fs_type strings.
144  * Return 0 on match, -1 otherwise.
145  */
146 static int
147 compare_sign(char *str1, char *str2)
148 {
149 	char *end = str1+SIGNLEN;
150 
151 	while (str1 != end) {
152 		if (*str1 != *str2) {
153 			return -1;
154 		}
155 		str1++;
156 		str2++;
157 	}
158 
159 	return 0;
160 }
161 
162 
163 /*
164  * Extract zero terminated short name from a directory entry.
165  */
166 static void get_name (dir_entry *dirent, char *s_name)
167 {
168 	char *ptr;
169 
170 	memcpy (s_name, dirent->name, 8);
171 	s_name[8] = '\0';
172 	ptr = s_name;
173 	while (*ptr && *ptr != ' ')
174 		ptr++;
175 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
176 		*ptr = '.';
177 		ptr++;
178 		memcpy (ptr, dirent->ext, 3);
179 		ptr[3] = '\0';
180 		while (*ptr && *ptr != ' ')
181 			ptr++;
182 	}
183 	*ptr = '\0';
184 	if (*s_name == DELETED_FLAG)
185 		*s_name = '\0';
186 	else if (*s_name == aRING)
187 		*s_name = '�';
188 	downcase (s_name);
189 }
190 
191 /*
192  * Get the entry at index 'entry' in a FAT (12/16/32) table.
193  * On failure 0x00 is returned.
194  */
195 static __u32
196 get_fatent(fsdata *mydata, __u32 entry)
197 {
198 	__u32 bufnum;
199 	__u32 offset;
200 	__u32 ret = 0x00;
201 
202 	switch (mydata->fatsize) {
203 	case 32:
204 		bufnum = entry / FAT32BUFSIZE;
205 		offset = entry - bufnum * FAT32BUFSIZE;
206 		break;
207 	case 16:
208 		bufnum = entry / FAT16BUFSIZE;
209 		offset = entry - bufnum * FAT16BUFSIZE;
210 		break;
211 	case 12:
212 		bufnum = entry / FAT12BUFSIZE;
213 		offset = entry - bufnum * FAT12BUFSIZE;
214 		break;
215 
216 	default:
217 		/* Unsupported FAT size */
218 		return ret;
219 	}
220 
221 	/* Read a new block of FAT entries into the cache. */
222 	if (bufnum != mydata->fatbufnum) {
223 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
224 		__u8 *bufptr = mydata->fatbuf;
225 		__u32 fatlength = mydata->fatlength;
226 		__u32 startblock = bufnum * FATBUFBLOCKS;
227 
228 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
229 		startblock += mydata->fat_sect;	/* Offset from start of disk */
230 
231 		if (getsize > fatlength) getsize = fatlength;
232 		if (disk_read(startblock, getsize, bufptr) < 0) {
233 			FAT_DPRINT("Error reading FAT blocks\n");
234 			return ret;
235 		}
236 		mydata->fatbufnum = bufnum;
237 	}
238 
239 	/* Get the actual entry from the table */
240 	switch (mydata->fatsize) {
241 	case 32:
242 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
243 		break;
244 	case 16:
245 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
246 		break;
247 	case 12: {
248 		__u32 off16 = (offset*3)/4;
249 		__u16 val1, val2;
250 
251 		switch (offset & 0x3) {
252 		case 0:
253 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
254 			ret &= 0xfff;
255 			break;
256 		case 1:
257 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
258 			val1 &= 0xf000;
259 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
260 			val2 &= 0x00ff;
261 			ret = (val2 << 4) | (val1 >> 12);
262 			break;
263 		case 2:
264 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
265 			val1 &= 0xff00;
266 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
267 			val2 &= 0x000f;
268 			ret = (val2 << 8) | (val1 >> 8);
269 			break;
270 		case 3:
271 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
272 			ret = (ret & 0xfff0) >> 4;
273 			break;
274 		default:
275 			break;
276 		}
277 	}
278 	break;
279 	}
280 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
281 
282 	return ret;
283 }
284 
285 
286 /*
287  * Read at most 'size' bytes from the specified cluster into 'buffer'.
288  * Return 0 on success, -1 otherwise.
289  */
290 static int
291 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
292 {
293 	int idx = 0;
294 	__u32 startsect;
295 
296 	if (clustnum > 0) {
297 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
298 	} else {
299 		startsect = mydata->rootdir_sect;
300 	}
301 
302 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
303 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
304 		FAT_DPRINT("Error reading data\n");
305 		return -1;
306 	}
307 	if(size % FS_BLOCK_SIZE) {
308 		__u8 tmpbuf[FS_BLOCK_SIZE];
309 		idx= size/FS_BLOCK_SIZE;
310 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
311 			FAT_DPRINT("Error reading data\n");
312 			return -1;
313 		}
314 		buffer += idx*FS_BLOCK_SIZE;
315 
316 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
317 		return 0;
318 	}
319 
320 	return 0;
321 }
322 
323 
324 /*
325  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
326  * into 'buffer'.
327  * Return the number of bytes read or -1 on fatal errors.
328  */
329 static long
330 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
331 	     unsigned long maxsize)
332 {
333 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
334 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
335 	__u32 curclust = START(dentptr);
336 	__u32 endclust, newclust;
337 	unsigned long actsize;
338 
339 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
340 
341 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
342 
343 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
344 
345 	actsize=bytesperclust;
346 	endclust=curclust;
347 	do {
348 		/* search for consecutive clusters */
349 		while(actsize < filesize) {
350 			newclust = get_fatent(mydata, endclust);
351 			if((newclust -1)!=endclust)
352 				goto getit;
353 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
354 				FAT_DPRINT("curclust: 0x%x\n", newclust);
355 				FAT_DPRINT("Invalid FAT entry\n");
356 				return gotsize;
357 			}
358 			endclust=newclust;
359 			actsize+= bytesperclust;
360 		}
361 		/* actsize >= file size */
362 		actsize -= bytesperclust;
363 		/* get remaining clusters */
364 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
365 			FAT_ERROR("Error reading cluster\n");
366 			return -1;
367 		}
368 		/* get remaining bytes */
369 		gotsize += (int)actsize;
370 		filesize -= actsize;
371 		buffer += actsize;
372 		actsize= filesize;
373 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
374 			FAT_ERROR("Error reading cluster\n");
375 			return -1;
376 		}
377 		gotsize+=actsize;
378 		return gotsize;
379 getit:
380 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
381 			FAT_ERROR("Error reading cluster\n");
382 			return -1;
383 		}
384 		gotsize += (int)actsize;
385 		filesize -= actsize;
386 		buffer += actsize;
387 		curclust = get_fatent(mydata, endclust);
388 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
389 			FAT_DPRINT("curclust: 0x%x\n", curclust);
390 			FAT_ERROR("Invalid FAT entry\n");
391 			return gotsize;
392 		}
393 		actsize=bytesperclust;
394 		endclust=curclust;
395 	} while (1);
396 }
397 
398 
399 #ifdef CONFIG_SUPPORT_VFAT
400 /*
401  * Extract the file name information from 'slotptr' into 'l_name',
402  * starting at l_name[*idx].
403  * Return 1 if terminator (zero byte) is found, 0 otherwise.
404  */
405 static int
406 slot2str(dir_slot *slotptr, char *l_name, int *idx)
407 {
408 	int j;
409 
410 	for (j = 0; j <= 8; j += 2) {
411 		l_name[*idx] = slotptr->name0_4[j];
412 		if (l_name[*idx] == 0x00) return 1;
413 		(*idx)++;
414 	}
415 	for (j = 0; j <= 10; j += 2) {
416 		l_name[*idx] = slotptr->name5_10[j];
417 		if (l_name[*idx] == 0x00) 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) return 1;
423 		(*idx)++;
424 	}
425 
426 	return 0;
427 }
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 static int
438 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
439 	     dir_entry *retdent, char *l_name)
440 {
441 	dir_entry *realdent;
442 	dir_slot  *slotptr = (dir_slot*) retdent;
443 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
444 	__u8	   counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
445 	int idx = 0;
446 
447 	while ((__u8*)slotptr < nextclust) {
448 		if (counter == 0) break;
449 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
450 			return -1;
451 		slotptr++;
452 		counter--;
453 	}
454 
455 	if ((__u8*)slotptr >= nextclust) {
456 		dir_slot *slotptr2;
457 
458 		slotptr--;
459 		curclust = get_fatent(mydata, curclust);
460 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
461 			FAT_DPRINT("curclust: 0x%x\n", curclust);
462 			FAT_ERROR("Invalid FAT entry\n");
463 			return -1;
464 		}
465 		if (get_cluster(mydata, curclust, get_vfatname_block,
466 				mydata->clust_size * SECTOR_SIZE) != 0) {
467 			FAT_DPRINT("Error: reading directory block\n");
468 			return -1;
469 		}
470 		slotptr2 = (dir_slot*) get_vfatname_block;
471 		while (slotptr2->id > 0x01) {
472 			slotptr2++;
473 		}
474 		/* Save the real directory entry */
475 		realdent = (dir_entry*)slotptr2 + 1;
476 		while ((__u8*)slotptr2 >= get_vfatname_block) {
477 			slot2str(slotptr2, l_name, &idx);
478 			slotptr2--;
479 		}
480 	} else {
481 		/* Save the real directory entry */
482 		realdent = (dir_entry*)slotptr;
483 	}
484 
485 	do {
486 		slotptr--;
487 		if (slot2str(slotptr, l_name, &idx)) break;
488 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
489 
490 	l_name[idx] = '\0';
491 	if (*l_name == DELETED_FLAG) *l_name = '\0';
492 	else if (*l_name == aRING) *l_name = '�';
493 	downcase(l_name);
494 
495 	/* Return the real directory entry */
496 	memcpy(retdent, realdent, sizeof(dir_entry));
497 
498 	return 0;
499 }
500 
501 
502 /* Calculate short name checksum */
503 static __u8
504 mkcksum(const char *str)
505 {
506 	int i;
507 	__u8 ret = 0;
508 
509 	for (i = 0; i < 11; i++) {
510 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
511 	}
512 
513 	return ret;
514 }
515 #endif
516 
517 
518 /*
519  * Get the directory entry associated with 'filename' from the directory
520  * starting at 'startsect'
521  */
522 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
523 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
524 				   char *filename, dir_entry * retdent,
525 				   int dols)
526 {
527     __u16 prevcksum = 0xffff;
528     __u32 curclust = START (retdent);
529     int files = 0, dirs = 0;
530 
531     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
532     while (1) {
533 	dir_entry *dentptr;
534 	int i;
535 
536 	if (get_cluster (mydata, curclust, get_dentfromdir_block,
537 		 mydata->clust_size * SECTOR_SIZE) != 0) {
538 	    FAT_DPRINT ("Error: reading directory block\n");
539 	    return NULL;
540 	}
541 	dentptr = (dir_entry *) get_dentfromdir_block;
542 	for (i = 0; i < DIRENTSPERCLUST; i++) {
543 	    char s_name[14], l_name[256];
544 
545 	    l_name[0] = '\0';
546 	    if (dentptr->name[0] == DELETED_FLAG) {
547 		    dentptr++;
548 		    continue;
549 	    }
550 	    if ((dentptr->attr & ATTR_VOLUME)) {
551 #ifdef CONFIG_SUPPORT_VFAT
552 		if ((dentptr->attr & ATTR_VFAT) &&
553 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
554 		    prevcksum = ((dir_slot *) dentptr)
555 			    ->alias_checksum;
556 		    get_vfatname (mydata, curclust, get_dentfromdir_block,
557 				  dentptr, l_name);
558 		    if (dols) {
559 			int isdir = (dentptr->attr & ATTR_DIR);
560 			char dirc;
561 			int doit = 0;
562 
563 			if (isdir) {
564 			    dirs++;
565 			    dirc = '/';
566 			    doit = 1;
567 			} else {
568 			    dirc = ' ';
569 			    if (l_name[0] != 0) {
570 				files++;
571 				doit = 1;
572 			    }
573 			}
574 			if (doit) {
575 			    if (dirc == ' ') {
576 				printf (" %8ld   %s%c\n",
577 					(long) FAT2CPU32 (dentptr->size),
578 					l_name, dirc);
579 			    } else {
580 				printf ("            %s%c\n", l_name, dirc);
581 			    }
582 			}
583 			dentptr++;
584 			continue;
585 		    }
586 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
587 		} else
588 #endif
589 		{
590 		    /* Volume label or VFAT entry */
591 		    dentptr++;
592 		    continue;
593 		}
594 	    }
595 	    if (dentptr->name[0] == 0) {
596 		if (dols) {
597 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
598 		}
599 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
600 		return NULL;
601 	    }
602 #ifdef CONFIG_SUPPORT_VFAT
603 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
604 		dentptr++;
605 		continue;
606 	    }
607 #endif
608 	    get_name (dentptr, s_name);
609 	    if (dols) {
610 		int isdir = (dentptr->attr & ATTR_DIR);
611 		char dirc;
612 		int doit = 0;
613 
614 		if (isdir) {
615 		    dirs++;
616 		    dirc = '/';
617 		    doit = 1;
618 		} else {
619 		    dirc = ' ';
620 		    if (s_name[0] != 0) {
621 			files++;
622 			doit = 1;
623 		    }
624 		}
625 		if (doit) {
626 		    if (dirc == ' ') {
627 			printf (" %8ld   %s%c\n",
628 				(long) FAT2CPU32 (dentptr->size), s_name,
629 				dirc);
630 		    } else {
631 			printf ("            %s%c\n", s_name, dirc);
632 		    }
633 		}
634 		dentptr++;
635 		continue;
636 	    }
637 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
638 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
639 		dentptr++;
640 		continue;
641 	    }
642 	    memcpy (retdent, dentptr, sizeof (dir_entry));
643 
644 	    FAT_DPRINT ("DentName: %s", s_name);
645 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
646 	    FAT_DPRINT (", size:  0x%x %s\n",
647 			FAT2CPU32 (dentptr->size),
648 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
649 
650 	    return retdent;
651 	}
652 	curclust = get_fatent (mydata, curclust);
653 	if (CHECK_CLUST(curclust, mydata->fatsize)) {
654 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
655 	    FAT_ERROR ("Invalid FAT entry\n");
656 	    return NULL;
657 	}
658     }
659 
660     return NULL;
661 }
662 
663 
664 /*
665  * Read boot sector and volume info from a FAT filesystem
666  */
667 static int
668 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
669 {
670 	__u8 block[FS_BLOCK_SIZE];
671 	volume_info *vistart;
672 
673 	if (disk_read(0, 1, block) < 0) {
674 		FAT_DPRINT("Error: reading block\n");
675 		return -1;
676 	}
677 
678 	memcpy(bs, block, sizeof(boot_sector));
679 	bs->reserved	= FAT2CPU16(bs->reserved);
680 	bs->fat_length	= FAT2CPU16(bs->fat_length);
681 	bs->secs_track	= FAT2CPU16(bs->secs_track);
682 	bs->heads	= FAT2CPU16(bs->heads);
683 #if 0 /* UNUSED */
684 	bs->hidden	= FAT2CPU32(bs->hidden);
685 #endif
686 	bs->total_sect	= FAT2CPU32(bs->total_sect);
687 
688 	/* FAT32 entries */
689 	if (bs->fat_length == 0) {
690 		/* Assume FAT32 */
691 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
692 		bs->flags	 = FAT2CPU16(bs->flags);
693 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
694 		bs->info_sector  = FAT2CPU16(bs->info_sector);
695 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
696 		vistart = (volume_info*) (block + sizeof(boot_sector));
697 		*fatsize = 32;
698 	} else {
699 		vistart = (volume_info*) &(bs->fat32_length);
700 		*fatsize = 0;
701 	}
702 	memcpy(volinfo, vistart, sizeof(volume_info));
703 
704 	/* Terminate fs_type string. Writing past the end of vistart
705 	   is ok - it's just the buffer. */
706 	vistart->fs_type[8] = '\0';
707 
708 	if (*fatsize == 32) {
709 		if (compare_sign(FAT32_SIGN, vistart->fs_type) == 0) {
710 			return 0;
711 		}
712 	} else {
713 		if (compare_sign(FAT12_SIGN, vistart->fs_type) == 0) {
714 			*fatsize = 12;
715 			return 0;
716 		}
717 		if (compare_sign(FAT16_SIGN, vistart->fs_type) == 0) {
718 			*fatsize = 16;
719 			return 0;
720 		}
721 	}
722 
723 	FAT_DPRINT("Error: broken fs_type sign\n");
724 	return -1;
725 }
726 
727 
728 __u8 do_fat_read_block[MAX_CLUSTSIZE];  /* Block buffer */
729 long
730 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
731 	     int dols)
732 {
733 #if CONFIG_NIOS /* NIOS CPU cannot access big automatic arrays */
734     static
735 #endif
736     char fnamecopy[2048];
737     boot_sector bs;
738     volume_info volinfo;
739     fsdata datablock;
740     fsdata *mydata = &datablock;
741     dir_entry *dentptr;
742     __u16 prevcksum = 0xffff;
743     char *subname = "";
744     int rootdir_size, cursect;
745     int idx, isdir = 0;
746     int files = 0, dirs = 0;
747     long ret = 0;
748     int firsttime;
749 
750     if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
751 	FAT_DPRINT ("Error: reading boot sector\n");
752 	return -1;
753     }
754     if (mydata->fatsize == 32) {
755 	mydata->fatlength = bs.fat32_length;
756     } else {
757 	mydata->fatlength = bs.fat_length;
758     }
759     mydata->fat_sect = bs.reserved;
760     cursect = mydata->rootdir_sect
761 	    = mydata->fat_sect + mydata->fatlength * bs.fats;
762     mydata->clust_size = bs.cluster_size;
763     if (mydata->fatsize == 32) {
764 	rootdir_size = mydata->clust_size;
765 	mydata->data_begin = mydata->rootdir_sect   /* + rootdir_size */
766 		- (mydata->clust_size * 2);
767     } else {
768 	rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
769 			* sizeof (dir_entry)) / SECTOR_SIZE;
770 	mydata->data_begin = mydata->rootdir_sect + rootdir_size
771 		- (mydata->clust_size * 2);
772     }
773     mydata->fatbufnum = -1;
774 
775     FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
776 		mydata->fatlength);
777     FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
778 		"Data begins at: %d\n",
779 		mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
780 		rootdir_size, mydata->data_begin);
781     FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
782 
783     /* "cwd" is always the root... */
784     while (ISDIRDELIM (*filename))
785 	filename++;
786     /* Make a copy of the filename and convert it to lowercase */
787     strcpy (fnamecopy, filename);
788     downcase (fnamecopy);
789     if (*fnamecopy == '\0') {
790 	if (!dols)
791 	    return -1;
792 	dols = LS_ROOT;
793     } else if ((idx = dirdelim (fnamecopy)) >= 0) {
794 	isdir = 1;
795 	fnamecopy[idx] = '\0';
796 	subname = fnamecopy + idx + 1;
797 	/* Handle multiple delimiters */
798 	while (ISDIRDELIM (*subname))
799 	    subname++;
800     } else if (dols) {
801 	isdir = 1;
802     }
803 
804     while (1) {
805 	int i;
806 
807 	if (disk_read (cursect, mydata->clust_size, do_fat_read_block) < 0) {
808 	    FAT_DPRINT ("Error: reading rootdir block\n");
809 	    return -1;
810 	}
811 	dentptr = (dir_entry *) do_fat_read_block;
812 	for (i = 0; i < DIRENTSPERBLOCK; i++) {
813 	    char s_name[14], l_name[256];
814 
815 	    l_name[0] = '\0';
816 	    if ((dentptr->attr & ATTR_VOLUME)) {
817 #ifdef CONFIG_SUPPORT_VFAT
818 		if ((dentptr->attr & ATTR_VFAT) &&
819 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
820 		    prevcksum = ((dir_slot *) dentptr)->alias_checksum;
821 		    get_vfatname (mydata, 0, do_fat_read_block, dentptr, l_name);
822 		    if (dols == LS_ROOT) {
823 			int isdir = (dentptr->attr & ATTR_DIR);
824 			char dirc;
825 			int doit = 0;
826 
827 			if (isdir) {
828 			    dirs++;
829 			    dirc = '/';
830 			    doit = 1;
831 			} else {
832 			    dirc = ' ';
833 			    if (l_name[0] != 0) {
834 				files++;
835 				doit = 1;
836 			    }
837 			}
838 			if (doit) {
839 			    if (dirc == ' ') {
840 				printf (" %8ld   %s%c\n",
841 					(long) FAT2CPU32 (dentptr->size),
842 					l_name, dirc);
843 			    } else {
844 				printf ("            %s%c\n", l_name, dirc);
845 			    }
846 			}
847 			dentptr++;
848 			continue;
849 		    }
850 		    FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
851 		} else
852 #endif
853 		{
854 		    /* Volume label or VFAT entry */
855 		    dentptr++;
856 		    continue;
857 		}
858 	    } else if (dentptr->name[0] == 0) {
859 		FAT_DPRINT ("RootDentname == NULL - %d\n", i);
860 		if (dols == LS_ROOT) {
861 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
862 		    return 0;
863 		}
864 		return -1;
865 	    }
866 #ifdef CONFIG_SUPPORT_VFAT
867 	    else if (dols == LS_ROOT
868 		     && mkcksum (dentptr->name) == prevcksum) {
869 		dentptr++;
870 		continue;
871 	    }
872 #endif
873 	    get_name (dentptr, s_name);
874 	    if (dols == LS_ROOT) {
875 		int isdir = (dentptr->attr & ATTR_DIR);
876 		char dirc;
877 		int doit = 0;
878 
879 		if (isdir) {
880 		    dirc = '/';
881 		    if (s_name[0] != 0) {
882 			dirs++;
883 			doit = 1;
884 		    }
885 		} else {
886 		    dirc = ' ';
887 		    if (s_name[0] != 0) {
888 			files++;
889 			doit = 1;
890 		    }
891 		}
892 		if (doit) {
893 		    if (dirc == ' ') {
894 			printf (" %8ld   %s%c\n",
895 				(long) FAT2CPU32 (dentptr->size), s_name,
896 				dirc);
897 		    } else {
898 			printf ("            %s%c\n", s_name, dirc);
899 		    }
900 		}
901 		dentptr++;
902 		continue;
903 	    }
904 	    if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
905 		FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
906 		dentptr++;
907 		continue;
908 	    }
909 	    if (isdir && !(dentptr->attr & ATTR_DIR))
910 		return -1;
911 
912 	    FAT_DPRINT ("RootName: %s", s_name);
913 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
914 	    FAT_DPRINT (", size:  0x%x %s\n",
915 			FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
916 
917 	    goto rootdir_done;  /* We got a match */
918 	}
919 	cursect++;
920     }
921   rootdir_done:
922 
923     firsttime = 1;
924     while (isdir) {
925 	int startsect = mydata->data_begin
926 		+ START (dentptr) * mydata->clust_size;
927 	dir_entry dent;
928 	char *nextname = NULL;
929 
930 	dent = *dentptr;
931 	dentptr = &dent;
932 
933 	idx = dirdelim (subname);
934 	if (idx >= 0) {
935 	    subname[idx] = '\0';
936 	    nextname = subname + idx + 1;
937 	    /* Handle multiple delimiters */
938 	    while (ISDIRDELIM (*nextname))
939 		nextname++;
940 	    if (dols && *nextname == '\0')
941 		firsttime = 0;
942 	} else {
943 	    if (dols && firsttime) {
944 		firsttime = 0;
945 	    } else {
946 		isdir = 0;
947 	    }
948 	}
949 
950 	if (get_dentfromdir (mydata, startsect, subname, dentptr,
951 			     isdir ? 0 : dols) == NULL) {
952 	    if (dols && !isdir)
953 		return 0;
954 	    return -1;
955 	}
956 
957 	if (idx >= 0) {
958 	    if (!(dentptr->attr & ATTR_DIR))
959 		return -1;
960 	    subname = nextname;
961 	}
962     }
963     ret = get_contents (mydata, dentptr, buffer, maxsize);
964     FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
965 
966     return ret;
967 }
968 
969 
970 int
971 file_fat_detectfs(void)
972 {
973 	boot_sector	bs;
974 	volume_info	volinfo;
975 	int		fatsize;
976 	char	vol_label[12];
977 
978 	if(cur_dev==NULL) {
979 		printf("No current device\n");
980 		return 1;
981 	}
982 #if defined(CONFIG_CMD_IDE) || \
983     defined(CONFIG_CMD_SCSI) || \
984     defined(CONFIG_CMD_USB) || \
985     defined(CONFIG_MMC)
986 	printf("Interface:  ");
987 	switch(cur_dev->if_type) {
988 		case IF_TYPE_IDE :	printf("IDE"); break;
989 		case IF_TYPE_SCSI :	printf("SCSI"); break;
990 		case IF_TYPE_ATAPI :	printf("ATAPI"); break;
991 		case IF_TYPE_USB :	printf("USB"); break;
992 		case IF_TYPE_DOC :	printf("DOC"); break;
993 		case IF_TYPE_MMC :	printf("MMC"); break;
994 		default :		printf("Unknown");
995 	}
996 	printf("\n  Device %d: ",cur_dev->dev);
997 	dev_print(cur_dev);
998 #endif
999 	if(read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1000 		printf("\nNo valid FAT fs found\n");
1001 		return 1;
1002 	}
1003 	memcpy (vol_label, volinfo.volume_label, 11);
1004 	vol_label[11] = '\0';
1005 	volinfo.fs_type[5]='\0';
1006 	printf("Partition %d: Filesystem: %s \"%s\"\n"
1007 			,cur_part,volinfo.fs_type,vol_label);
1008 	return 0;
1009 }
1010 
1011 
1012 int
1013 file_fat_ls(const char *dir)
1014 {
1015 	return do_fat_read(dir, NULL, 0, LS_YES);
1016 }
1017 
1018 
1019 long
1020 file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1021 {
1022 	printf("reading %s\n",filename);
1023 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1024 }
1025