xref: /openbmc/u-boot/fs/fat/fat.c (revision 10a451cd)
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_MG_DISK) || \
88      defined(CONFIG_CMD_SATA) || \
89      defined(CONFIG_CMD_SCSI) || \
90      defined(CONFIG_CMD_USB) || \
91      defined(CONFIG_MMC) || \
92      defined(CONFIG_SYSTEMACE) )
93 	/* First we assume, there is a MBR */
94 	if (!get_partition_info (dev_desc, part_no, &info)) {
95 		part_offset = info.start;
96 		cur_part = part_no;
97 	} else if (!strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3)) {
98 		/* ok, we assume we are on a PBR only */
99 		cur_part = 1;
100 		part_offset = 0;
101 	} else {
102 		printf ("** Partition %d not valid on device %d **\n",
103 				part_no, dev_desc->dev);
104 		return -1;
105 	}
106 
107 #else
108 	if (!strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET],"FAT",3)) {
109 		/* ok, we assume we are on a PBR only */
110 		cur_part = 1;
111 		part_offset = 0;
112 		info.start = part_offset;
113 	} else {
114 		/* FIXME we need to determine the start block of the
115 		 * partition where the DOS FS resides. This can be done
116 		 * by using the get_partition_info routine. For this
117 		 * purpose the libpart must be included.
118 		 */
119 		part_offset = 32;
120 		cur_part = 1;
121 	}
122 #endif
123 	return 0;
124 }
125 
126 
127 /*
128  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
129  * Return index into string if found, -1 otherwise.
130  */
131 static int
132 dirdelim(char *str)
133 {
134 	char *start = str;
135 
136 	while (*str != '\0') {
137 		if (ISDIRDELIM(*str)) return str - start;
138 		str++;
139 	}
140 	return -1;
141 }
142 
143 
144 /*
145  * Match volume_info fs_type strings.
146  * Return 0 on match, -1 otherwise.
147  */
148 static int
149 compare_sign(char *str1, char *str2)
150 {
151 	char *end = str1+SIGNLEN;
152 
153 	while (str1 != end) {
154 		if (*str1 != *str2) {
155 			return -1;
156 		}
157 		str1++;
158 		str2++;
159 	}
160 
161 	return 0;
162 }
163 
164 
165 /*
166  * Extract zero terminated short name from a directory entry.
167  */
168 static void get_name (dir_entry *dirent, char *s_name)
169 {
170 	char *ptr;
171 
172 	memcpy (s_name, dirent->name, 8);
173 	s_name[8] = '\0';
174 	ptr = s_name;
175 	while (*ptr && *ptr != ' ')
176 		ptr++;
177 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
178 		*ptr = '.';
179 		ptr++;
180 		memcpy (ptr, dirent->ext, 3);
181 		ptr[3] = '\0';
182 		while (*ptr && *ptr != ' ')
183 			ptr++;
184 	}
185 	*ptr = '\0';
186 	if (*s_name == DELETED_FLAG)
187 		*s_name = '\0';
188 	else if (*s_name == aRING)
189 		*s_name = DELETED_FLAG;
190 	downcase (s_name);
191 }
192 
193 /*
194  * Get the entry at index 'entry' in a FAT (12/16/32) table.
195  * On failure 0x00 is returned.
196  */
197 static __u32
198 get_fatent(fsdata *mydata, __u32 entry)
199 {
200 	__u32 bufnum;
201 	__u32 offset;
202 	__u32 ret = 0x00;
203 
204 	switch (mydata->fatsize) {
205 	case 32:
206 		bufnum = entry / FAT32BUFSIZE;
207 		offset = entry - bufnum * FAT32BUFSIZE;
208 		break;
209 	case 16:
210 		bufnum = entry / FAT16BUFSIZE;
211 		offset = entry - bufnum * FAT16BUFSIZE;
212 		break;
213 	case 12:
214 		bufnum = entry / FAT12BUFSIZE;
215 		offset = entry - bufnum * FAT12BUFSIZE;
216 		break;
217 
218 	default:
219 		/* Unsupported FAT size */
220 		return ret;
221 	}
222 
223 	/* Read a new block of FAT entries into the cache. */
224 	if (bufnum != mydata->fatbufnum) {
225 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
226 		__u8 *bufptr = mydata->fatbuf;
227 		__u32 fatlength = mydata->fatlength;
228 		__u32 startblock = bufnum * FATBUFBLOCKS;
229 
230 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
231 		startblock += mydata->fat_sect;	/* Offset from start of disk */
232 
233 		if (getsize > fatlength) getsize = fatlength;
234 		if (disk_read(startblock, getsize, bufptr) < 0) {
235 			FAT_DPRINT("Error reading FAT blocks\n");
236 			return ret;
237 		}
238 		mydata->fatbufnum = bufnum;
239 	}
240 
241 	/* Get the actual entry from the table */
242 	switch (mydata->fatsize) {
243 	case 32:
244 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
245 		break;
246 	case 16:
247 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
248 		break;
249 	case 12: {
250 		__u32 off16 = (offset*3)/4;
251 		__u16 val1, val2;
252 
253 		switch (offset & 0x3) {
254 		case 0:
255 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
256 			ret &= 0xfff;
257 			break;
258 		case 1:
259 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
260 			val1 &= 0xf000;
261 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
262 			val2 &= 0x00ff;
263 			ret = (val2 << 4) | (val1 >> 12);
264 			break;
265 		case 2:
266 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
267 			val1 &= 0xff00;
268 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
269 			val2 &= 0x000f;
270 			ret = (val2 << 8) | (val1 >> 8);
271 			break;
272 		case 3:
273 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
274 			ret = (ret & 0xfff0) >> 4;
275 			break;
276 		default:
277 			break;
278 		}
279 	}
280 	break;
281 	}
282 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
283 
284 	return ret;
285 }
286 
287 
288 /*
289  * Read at most 'size' bytes from the specified cluster into 'buffer'.
290  * Return 0 on success, -1 otherwise.
291  */
292 static int
293 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
294 {
295 	int idx = 0;
296 	__u32 startsect;
297 
298 	if (clustnum > 0) {
299 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
300 	} else {
301 		startsect = mydata->rootdir_sect;
302 	}
303 
304 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
305 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
306 		FAT_DPRINT("Error reading data\n");
307 		return -1;
308 	}
309 	if(size % FS_BLOCK_SIZE) {
310 		__u8 tmpbuf[FS_BLOCK_SIZE];
311 		idx= size/FS_BLOCK_SIZE;
312 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
313 			FAT_DPRINT("Error reading data\n");
314 			return -1;
315 		}
316 		buffer += idx*FS_BLOCK_SIZE;
317 
318 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
319 		return 0;
320 	}
321 
322 	return 0;
323 }
324 
325 
326 /*
327  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
328  * into 'buffer'.
329  * Return the number of bytes read or -1 on fatal errors.
330  */
331 static long
332 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
333 	     unsigned long maxsize)
334 {
335 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
336 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
337 	__u32 curclust = START(dentptr);
338 	__u32 endclust, newclust;
339 	unsigned long actsize;
340 
341 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
342 
343 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
344 
345 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
346 
347 	actsize=bytesperclust;
348 	endclust=curclust;
349 	do {
350 		/* search for consecutive clusters */
351 		while(actsize < filesize) {
352 			newclust = get_fatent(mydata, endclust);
353 			if((newclust -1)!=endclust)
354 				goto getit;
355 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
356 				FAT_DPRINT("curclust: 0x%x\n", newclust);
357 				FAT_DPRINT("Invalid FAT entry\n");
358 				return gotsize;
359 			}
360 			endclust=newclust;
361 			actsize+= bytesperclust;
362 		}
363 		/* actsize >= file size */
364 		actsize -= bytesperclust;
365 		/* get remaining clusters */
366 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
367 			FAT_ERROR("Error reading cluster\n");
368 			return -1;
369 		}
370 		/* get remaining bytes */
371 		gotsize += (int)actsize;
372 		filesize -= actsize;
373 		buffer += actsize;
374 		actsize= filesize;
375 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
376 			FAT_ERROR("Error reading cluster\n");
377 			return -1;
378 		}
379 		gotsize+=actsize;
380 		return gotsize;
381 getit:
382 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
383 			FAT_ERROR("Error reading cluster\n");
384 			return -1;
385 		}
386 		gotsize += (int)actsize;
387 		filesize -= actsize;
388 		buffer += actsize;
389 		curclust = get_fatent(mydata, endclust);
390 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
391 			FAT_DPRINT("curclust: 0x%x\n", curclust);
392 			FAT_ERROR("Invalid FAT entry\n");
393 			return gotsize;
394 		}
395 		actsize=bytesperclust;
396 		endclust=curclust;
397 	} while (1);
398 }
399 
400 
401 #ifdef CONFIG_SUPPORT_VFAT
402 /*
403  * Extract the file name information from 'slotptr' into 'l_name',
404  * starting at l_name[*idx].
405  * Return 1 if terminator (zero byte) is found, 0 otherwise.
406  */
407 static int
408 slot2str(dir_slot *slotptr, char *l_name, int *idx)
409 {
410 	int j;
411 
412 	for (j = 0; j <= 8; j += 2) {
413 		l_name[*idx] = slotptr->name0_4[j];
414 		if (l_name[*idx] == 0x00) return 1;
415 		(*idx)++;
416 	}
417 	for (j = 0; j <= 10; j += 2) {
418 		l_name[*idx] = slotptr->name5_10[j];
419 		if (l_name[*idx] == 0x00) return 1;
420 		(*idx)++;
421 	}
422 	for (j = 0; j <= 2; j += 2) {
423 		l_name[*idx] = slotptr->name11_12[j];
424 		if (l_name[*idx] == 0x00) return 1;
425 		(*idx)++;
426 	}
427 
428 	return 0;
429 }
430 
431 
432 /*
433  * Extract the full long filename starting at 'retdent' (which is really
434  * a slot) into 'l_name'. If successful also copy the real directory entry
435  * into 'retdent'
436  * Return 0 on success, -1 otherwise.
437  */
438 __attribute__ ((__aligned__(__alignof__(dir_entry))))
439 __u8 get_vfatname_block[MAX_CLUSTSIZE];
440 static int
441 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
442 	     dir_entry *retdent, char *l_name)
443 {
444 	dir_entry *realdent;
445 	dir_slot  *slotptr = (dir_slot*) retdent;
446 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
447 	__u8	   counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
448 	int idx = 0;
449 
450 	while ((__u8*)slotptr < nextclust) {
451 		if (counter == 0) break;
452 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
453 			return -1;
454 		slotptr++;
455 		counter--;
456 	}
457 
458 	if ((__u8*)slotptr >= nextclust) {
459 		dir_slot *slotptr2;
460 
461 		slotptr--;
462 		curclust = get_fatent(mydata, curclust);
463 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
464 			FAT_DPRINT("curclust: 0x%x\n", curclust);
465 			FAT_ERROR("Invalid FAT entry\n");
466 			return -1;
467 		}
468 		if (get_cluster(mydata, curclust, get_vfatname_block,
469 				mydata->clust_size * SECTOR_SIZE) != 0) {
470 			FAT_DPRINT("Error: reading directory block\n");
471 			return -1;
472 		}
473 		slotptr2 = (dir_slot*) get_vfatname_block;
474 		while (slotptr2->id > 0x01) {
475 			slotptr2++;
476 		}
477 		/* Save the real directory entry */
478 		realdent = (dir_entry*)slotptr2 + 1;
479 		while ((__u8*)slotptr2 >= get_vfatname_block) {
480 			slot2str(slotptr2, l_name, &idx);
481 			slotptr2--;
482 		}
483 	} else {
484 		/* Save the real directory entry */
485 		realdent = (dir_entry*)slotptr;
486 	}
487 
488 	do {
489 		slotptr--;
490 		if (slot2str(slotptr, l_name, &idx)) break;
491 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
492 
493 	l_name[idx] = '\0';
494 	if (*l_name == DELETED_FLAG) *l_name = '\0';
495 	else if (*l_name == aRING) *l_name = DELETED_FLAG;
496 	downcase(l_name);
497 
498 	/* Return the real directory entry */
499 	memcpy(retdent, realdent, sizeof(dir_entry));
500 
501 	return 0;
502 }
503 
504 
505 /* Calculate short name checksum */
506 static __u8
507 mkcksum(const char *str)
508 {
509 	int i;
510 	__u8 ret = 0;
511 
512 	for (i = 0; i < 11; i++) {
513 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
514 	}
515 
516 	return ret;
517 }
518 #endif
519 
520 
521 /*
522  * Get the directory entry associated with 'filename' from the directory
523  * starting at 'startsect'
524  */
525 __attribute__ ((__aligned__(__alignof__(dir_entry))))
526 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
527 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
528 				   char *filename, dir_entry * retdent,
529 				   int dols)
530 {
531     __u16 prevcksum = 0xffff;
532     __u32 curclust = START (retdent);
533     int files = 0, dirs = 0;
534 
535     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
536     while (1) {
537 	dir_entry *dentptr;
538 	int i;
539 
540 	if (get_cluster (mydata, curclust, get_dentfromdir_block,
541 		 mydata->clust_size * SECTOR_SIZE) != 0) {
542 	    FAT_DPRINT ("Error: reading directory block\n");
543 	    return NULL;
544 	}
545 	dentptr = (dir_entry *) get_dentfromdir_block;
546 	for (i = 0; i < DIRENTSPERCLUST; i++) {
547 	    char s_name[14], l_name[256];
548 
549 	    l_name[0] = '\0';
550 	    if (dentptr->name[0] == DELETED_FLAG) {
551 		    dentptr++;
552 		    continue;
553 	    }
554 	    if ((dentptr->attr & ATTR_VOLUME)) {
555 #ifdef CONFIG_SUPPORT_VFAT
556 		if ((dentptr->attr & ATTR_VFAT) &&
557 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
558 		    prevcksum = ((dir_slot *) dentptr)
559 			    ->alias_checksum;
560 		    get_vfatname (mydata, curclust, get_dentfromdir_block,
561 				  dentptr, l_name);
562 		    if (dols) {
563 			int isdir = (dentptr->attr & ATTR_DIR);
564 			char dirc;
565 			int doit = 0;
566 
567 			if (isdir) {
568 			    dirs++;
569 			    dirc = '/';
570 			    doit = 1;
571 			} else {
572 			    dirc = ' ';
573 			    if (l_name[0] != 0) {
574 				files++;
575 				doit = 1;
576 			    }
577 			}
578 			if (doit) {
579 			    if (dirc == ' ') {
580 				printf (" %8ld   %s%c\n",
581 					(long) FAT2CPU32 (dentptr->size),
582 					l_name, dirc);
583 			    } else {
584 				printf ("            %s%c\n", l_name, dirc);
585 			    }
586 			}
587 			dentptr++;
588 			continue;
589 		    }
590 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
591 		} else
592 #endif
593 		{
594 		    /* Volume label or VFAT entry */
595 		    dentptr++;
596 		    continue;
597 		}
598 	    }
599 	    if (dentptr->name[0] == 0) {
600 		if (dols) {
601 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
602 		}
603 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
604 		return NULL;
605 	    }
606 #ifdef CONFIG_SUPPORT_VFAT
607 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
608 		dentptr++;
609 		continue;
610 	    }
611 #endif
612 	    get_name (dentptr, s_name);
613 	    if (dols) {
614 		int isdir = (dentptr->attr & ATTR_DIR);
615 		char dirc;
616 		int doit = 0;
617 
618 		if (isdir) {
619 		    dirs++;
620 		    dirc = '/';
621 		    doit = 1;
622 		} else {
623 		    dirc = ' ';
624 		    if (s_name[0] != 0) {
625 			files++;
626 			doit = 1;
627 		    }
628 		}
629 		if (doit) {
630 		    if (dirc == ' ') {
631 			printf (" %8ld   %s%c\n",
632 				(long) FAT2CPU32 (dentptr->size), s_name,
633 				dirc);
634 		    } else {
635 			printf ("            %s%c\n", s_name, dirc);
636 		    }
637 		}
638 		dentptr++;
639 		continue;
640 	    }
641 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
642 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
643 		dentptr++;
644 		continue;
645 	    }
646 	    memcpy (retdent, dentptr, sizeof (dir_entry));
647 
648 	    FAT_DPRINT ("DentName: %s", s_name);
649 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
650 	    FAT_DPRINT (", size:  0x%x %s\n",
651 			FAT2CPU32 (dentptr->size),
652 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
653 
654 	    return retdent;
655 	}
656 	curclust = get_fatent (mydata, curclust);
657 	if (CHECK_CLUST(curclust, mydata->fatsize)) {
658 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
659 	    FAT_ERROR ("Invalid FAT entry\n");
660 	    return NULL;
661 	}
662     }
663 
664     return NULL;
665 }
666 
667 
668 /*
669  * Read boot sector and volume info from a FAT filesystem
670  */
671 static int
672 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
673 {
674 	__u8 block[FS_BLOCK_SIZE];
675 	volume_info *vistart;
676 	char *fstype;
677 
678 	if (disk_read(0, 1, block) < 0) {
679 		FAT_DPRINT("Error: reading block\n");
680 		return -1;
681 	}
682 
683 	memcpy(bs, block, sizeof(boot_sector));
684 	bs->reserved	= FAT2CPU16(bs->reserved);
685 	bs->fat_length	= FAT2CPU16(bs->fat_length);
686 	bs->secs_track	= FAT2CPU16(bs->secs_track);
687 	bs->heads	= FAT2CPU16(bs->heads);
688 #if 0 /* UNUSED */
689 	bs->hidden	= FAT2CPU32(bs->hidden);
690 #endif
691 	bs->total_sect	= FAT2CPU32(bs->total_sect);
692 
693 	/* FAT32 entries */
694 	if (bs->fat_length == 0) {
695 		/* Assume FAT32 */
696 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
697 		bs->flags	 = FAT2CPU16(bs->flags);
698 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
699 		bs->info_sector  = FAT2CPU16(bs->info_sector);
700 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
701 		vistart = (volume_info*) (block + sizeof(boot_sector));
702 		*fatsize = 32;
703 	} else {
704 		vistart = (volume_info*) &(bs->fat32_length);
705 		*fatsize = 0;
706 	}
707 	memcpy(volinfo, vistart, sizeof(volume_info));
708 
709 	/*
710 	 * Terminate fs_type string. Writing past the end of vistart
711 	 * is ok - it's just the buffer.
712 	 */
713 	fstype = vistart->fs_type;
714 	fstype[8] = '\0';
715 
716 	if (*fatsize == 32) {
717 		if (compare_sign(FAT32_SIGN, vistart->fs_type) == 0) {
718 			return 0;
719 		}
720 	} else {
721 		if (compare_sign(FAT12_SIGN, vistart->fs_type) == 0) {
722 			*fatsize = 12;
723 			return 0;
724 		}
725 		if (compare_sign(FAT16_SIGN, vistart->fs_type) == 0) {
726 			*fatsize = 16;
727 			return 0;
728 		}
729 	}
730 
731 	FAT_DPRINT("Error: broken fs_type sign\n");
732 	return -1;
733 }
734 
735 __attribute__ ((__aligned__(__alignof__(dir_entry))))
736 __u8 do_fat_read_block[MAX_CLUSTSIZE];
737 long
738 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
739 	     int dols)
740 {
741 #if CONFIG_NIOS /* NIOS CPU cannot access big automatic arrays */
742     static
743 #endif
744     char fnamecopy[2048];
745     boot_sector bs;
746     volume_info volinfo;
747     fsdata datablock;
748     fsdata *mydata = &datablock;
749     dir_entry *dentptr;
750     __u16 prevcksum = 0xffff;
751     char *subname = "";
752     int rootdir_size, cursect;
753     int idx, isdir = 0;
754     int files = 0, dirs = 0;
755     long ret = 0;
756     int firsttime;
757 
758     if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
759 	FAT_DPRINT ("Error: reading boot sector\n");
760 	return -1;
761     }
762     if (mydata->fatsize == 32) {
763 	mydata->fatlength = bs.fat32_length;
764     } else {
765 	mydata->fatlength = bs.fat_length;
766     }
767     mydata->fat_sect = bs.reserved;
768     cursect = mydata->rootdir_sect
769 	    = mydata->fat_sect + mydata->fatlength * bs.fats;
770     mydata->clust_size = bs.cluster_size;
771     if (mydata->fatsize == 32) {
772 	rootdir_size = mydata->clust_size;
773 	mydata->data_begin = mydata->rootdir_sect   /* + rootdir_size */
774 		- (mydata->clust_size * 2);
775     } else {
776 	rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
777 			* sizeof (dir_entry)) / SECTOR_SIZE;
778 	mydata->data_begin = mydata->rootdir_sect + rootdir_size
779 		- (mydata->clust_size * 2);
780     }
781     mydata->fatbufnum = -1;
782 
783     FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
784 		mydata->fatlength);
785     FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
786 		"Data begins at: %d\n",
787 		mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
788 		rootdir_size, mydata->data_begin);
789     FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
790 
791     /* "cwd" is always the root... */
792     while (ISDIRDELIM (*filename))
793 	filename++;
794     /* Make a copy of the filename and convert it to lowercase */
795     strcpy (fnamecopy, filename);
796     downcase (fnamecopy);
797     if (*fnamecopy == '\0') {
798 	if (!dols)
799 	    return -1;
800 	dols = LS_ROOT;
801     } else if ((idx = dirdelim (fnamecopy)) >= 0) {
802 	isdir = 1;
803 	fnamecopy[idx] = '\0';
804 	subname = fnamecopy + idx + 1;
805 	/* Handle multiple delimiters */
806 	while (ISDIRDELIM (*subname))
807 	    subname++;
808     } else if (dols) {
809 	isdir = 1;
810     }
811 
812     while (1) {
813 	int i;
814 
815 	if (disk_read (cursect, mydata->clust_size, do_fat_read_block) < 0) {
816 	    FAT_DPRINT ("Error: reading rootdir block\n");
817 	    return -1;
818 	}
819 	dentptr = (dir_entry *) do_fat_read_block;
820 	for (i = 0; i < DIRENTSPERBLOCK; i++) {
821 	    char s_name[14], l_name[256];
822 
823 	    l_name[0] = '\0';
824 	    if ((dentptr->attr & ATTR_VOLUME)) {
825 #ifdef CONFIG_SUPPORT_VFAT
826 		if ((dentptr->attr & ATTR_VFAT) &&
827 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
828 		    prevcksum = ((dir_slot *) dentptr)->alias_checksum;
829 		    get_vfatname (mydata, 0, do_fat_read_block, dentptr, l_name);
830 		    if (dols == LS_ROOT) {
831 			int isdir = (dentptr->attr & ATTR_DIR);
832 			char dirc;
833 			int doit = 0;
834 
835 			if (isdir) {
836 			    dirs++;
837 			    dirc = '/';
838 			    doit = 1;
839 			} else {
840 			    dirc = ' ';
841 			    if (l_name[0] != 0) {
842 				files++;
843 				doit = 1;
844 			    }
845 			}
846 			if (doit) {
847 			    if (dirc == ' ') {
848 				printf (" %8ld   %s%c\n",
849 					(long) FAT2CPU32 (dentptr->size),
850 					l_name, dirc);
851 			    } else {
852 				printf ("            %s%c\n", l_name, dirc);
853 			    }
854 			}
855 			dentptr++;
856 			continue;
857 		    }
858 		    FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
859 		} else
860 #endif
861 		{
862 		    /* Volume label or VFAT entry */
863 		    dentptr++;
864 		    continue;
865 		}
866 	    } else if (dentptr->name[0] == 0) {
867 		FAT_DPRINT ("RootDentname == NULL - %d\n", i);
868 		if (dols == LS_ROOT) {
869 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
870 		    return 0;
871 		}
872 		return -1;
873 	    }
874 #ifdef CONFIG_SUPPORT_VFAT
875 	    else if (dols == LS_ROOT
876 		     && mkcksum (dentptr->name) == prevcksum) {
877 		dentptr++;
878 		continue;
879 	    }
880 #endif
881 	    get_name (dentptr, s_name);
882 	    if (dols == LS_ROOT) {
883 		int isdir = (dentptr->attr & ATTR_DIR);
884 		char dirc;
885 		int doit = 0;
886 
887 		if (isdir) {
888 		    dirc = '/';
889 		    if (s_name[0] != 0) {
890 			dirs++;
891 			doit = 1;
892 		    }
893 		} else {
894 		    dirc = ' ';
895 		    if (s_name[0] != 0) {
896 			files++;
897 			doit = 1;
898 		    }
899 		}
900 		if (doit) {
901 		    if (dirc == ' ') {
902 			printf (" %8ld   %s%c\n",
903 				(long) FAT2CPU32 (dentptr->size), s_name,
904 				dirc);
905 		    } else {
906 			printf ("            %s%c\n", s_name, dirc);
907 		    }
908 		}
909 		dentptr++;
910 		continue;
911 	    }
912 	    if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
913 		FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
914 		dentptr++;
915 		continue;
916 	    }
917 	    if (isdir && !(dentptr->attr & ATTR_DIR))
918 		return -1;
919 
920 	    FAT_DPRINT ("RootName: %s", s_name);
921 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
922 	    FAT_DPRINT (", size:  0x%x %s\n",
923 			FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
924 
925 	    goto rootdir_done;  /* We got a match */
926 	}
927 	cursect++;
928     }
929   rootdir_done:
930 
931     firsttime = 1;
932     while (isdir) {
933 	int startsect = mydata->data_begin
934 		+ START (dentptr) * mydata->clust_size;
935 	dir_entry dent;
936 	char *nextname = NULL;
937 
938 	dent = *dentptr;
939 	dentptr = &dent;
940 
941 	idx = dirdelim (subname);
942 	if (idx >= 0) {
943 	    subname[idx] = '\0';
944 	    nextname = subname + idx + 1;
945 	    /* Handle multiple delimiters */
946 	    while (ISDIRDELIM (*nextname))
947 		nextname++;
948 	    if (dols && *nextname == '\0')
949 		firsttime = 0;
950 	} else {
951 	    if (dols && firsttime) {
952 		firsttime = 0;
953 	    } else {
954 		isdir = 0;
955 	    }
956 	}
957 
958 	if (get_dentfromdir (mydata, startsect, subname, dentptr,
959 			     isdir ? 0 : dols) == NULL) {
960 	    if (dols && !isdir)
961 		return 0;
962 	    return -1;
963 	}
964 
965 	if (idx >= 0) {
966 	    if (!(dentptr->attr & ATTR_DIR))
967 		return -1;
968 	    subname = nextname;
969 	}
970     }
971     ret = get_contents (mydata, dentptr, buffer, maxsize);
972     FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
973 
974     return ret;
975 }
976 
977 
978 int
979 file_fat_detectfs(void)
980 {
981 	boot_sector	bs;
982 	volume_info	volinfo;
983 	int		fatsize;
984 	char	vol_label[12];
985 
986 	if(cur_dev==NULL) {
987 		printf("No current device\n");
988 		return 1;
989 	}
990 #if defined(CONFIG_CMD_IDE) || \
991     defined(CONFIG_CMD_MG_DISK) || \
992     defined(CONFIG_CMD_SATA) || \
993     defined(CONFIG_CMD_SCSI) || \
994     defined(CONFIG_CMD_USB) || \
995     defined(CONFIG_MMC)
996 	printf("Interface:  ");
997 	switch(cur_dev->if_type) {
998 		case IF_TYPE_IDE :	printf("IDE"); break;
999 		case IF_TYPE_SATA :	printf("SATA"); break;
1000 		case IF_TYPE_SCSI :	printf("SCSI"); break;
1001 		case IF_TYPE_ATAPI :	printf("ATAPI"); break;
1002 		case IF_TYPE_USB :	printf("USB"); break;
1003 		case IF_TYPE_DOC :	printf("DOC"); break;
1004 		case IF_TYPE_MMC :	printf("MMC"); break;
1005 		default :		printf("Unknown");
1006 	}
1007 	printf("\n  Device %d: ",cur_dev->dev);
1008 	dev_print(cur_dev);
1009 #endif
1010 	if(read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1011 		printf("\nNo valid FAT fs found\n");
1012 		return 1;
1013 	}
1014 	memcpy (vol_label, volinfo.volume_label, 11);
1015 	vol_label[11] = '\0';
1016 	volinfo.fs_type[5]='\0';
1017 	printf("Partition %d: Filesystem: %s \"%s\"\n"
1018 			,cur_part,volinfo.fs_type,vol_label);
1019 	return 0;
1020 }
1021 
1022 
1023 int
1024 file_fat_ls(const char *dir)
1025 {
1026 	return do_fat_read(dir, NULL, 0, LS_YES);
1027 }
1028 
1029 
1030 long
1031 file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1032 {
1033 	printf("reading %s\n",filename);
1034 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1035 }
1036