xref: /openbmc/u-boot/fs/fat/fat.c (revision 24113a44)
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_SATA) || \
88      defined(CONFIG_CMD_SCSI) || \
89      defined(CONFIG_CMD_USB) || \
90      defined(CONFIG_MMC) || \
91      defined(CONFIG_SYSTEMACE) )
92 	/* First we assume, there is a MBR */
93 	if (!get_partition_info (dev_desc, part_no, &info)) {
94 		part_offset = info.start;
95 		cur_part = part_no;
96 	} else if (!strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3)) {
97 		/* ok, we assume we are on a PBR only */
98 		cur_part = 1;
99 		part_offset = 0;
100 	} else {
101 		printf ("** Partition %d not valid on device %d **\n",
102 				part_no, dev_desc->dev);
103 		return -1;
104 	}
105 
106 #else
107 	if (!strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET],"FAT",3)) {
108 		/* ok, we assume we are on a PBR only */
109 		cur_part = 1;
110 		part_offset = 0;
111 		info.start = part_offset;
112 	} else {
113 		/* FIXME we need to determine the start block of the
114 		 * partition where the DOS FS resides. This can be done
115 		 * by using the get_partition_info routine. For this
116 		 * purpose the libpart must be included.
117 		 */
118 		part_offset = 32;
119 		cur_part = 1;
120 	}
121 #endif
122 	return 0;
123 }
124 
125 
126 /*
127  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
128  * Return index into string if found, -1 otherwise.
129  */
130 static int
131 dirdelim(char *str)
132 {
133 	char *start = str;
134 
135 	while (*str != '\0') {
136 		if (ISDIRDELIM(*str)) return str - start;
137 		str++;
138 	}
139 	return -1;
140 }
141 
142 
143 /*
144  * Match volume_info fs_type strings.
145  * Return 0 on match, -1 otherwise.
146  */
147 static int
148 compare_sign(char *str1, char *str2)
149 {
150 	char *end = str1+SIGNLEN;
151 
152 	while (str1 != end) {
153 		if (*str1 != *str2) {
154 			return -1;
155 		}
156 		str1++;
157 		str2++;
158 	}
159 
160 	return 0;
161 }
162 
163 
164 /*
165  * Extract zero terminated short name from a directory entry.
166  */
167 static void get_name (dir_entry *dirent, char *s_name)
168 {
169 	char *ptr;
170 
171 	memcpy (s_name, dirent->name, 8);
172 	s_name[8] = '\0';
173 	ptr = s_name;
174 	while (*ptr && *ptr != ' ')
175 		ptr++;
176 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
177 		*ptr = '.';
178 		ptr++;
179 		memcpy (ptr, dirent->ext, 3);
180 		ptr[3] = '\0';
181 		while (*ptr && *ptr != ' ')
182 			ptr++;
183 	}
184 	*ptr = '\0';
185 	if (*s_name == DELETED_FLAG)
186 		*s_name = '\0';
187 	else if (*s_name == aRING)
188 		*s_name = DELETED_FLAG;
189 	downcase (s_name);
190 }
191 
192 /*
193  * Get the entry at index 'entry' in a FAT (12/16/32) table.
194  * On failure 0x00 is returned.
195  */
196 static __u32
197 get_fatent(fsdata *mydata, __u32 entry)
198 {
199 	__u32 bufnum;
200 	__u32 offset;
201 	__u32 ret = 0x00;
202 
203 	switch (mydata->fatsize) {
204 	case 32:
205 		bufnum = entry / FAT32BUFSIZE;
206 		offset = entry - bufnum * FAT32BUFSIZE;
207 		break;
208 	case 16:
209 		bufnum = entry / FAT16BUFSIZE;
210 		offset = entry - bufnum * FAT16BUFSIZE;
211 		break;
212 	case 12:
213 		bufnum = entry / FAT12BUFSIZE;
214 		offset = entry - bufnum * FAT12BUFSIZE;
215 		break;
216 
217 	default:
218 		/* Unsupported FAT size */
219 		return ret;
220 	}
221 
222 	/* Read a new block of FAT entries into the cache. */
223 	if (bufnum != mydata->fatbufnum) {
224 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
225 		__u8 *bufptr = mydata->fatbuf;
226 		__u32 fatlength = mydata->fatlength;
227 		__u32 startblock = bufnum * FATBUFBLOCKS;
228 
229 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
230 		startblock += mydata->fat_sect;	/* Offset from start of disk */
231 
232 		if (getsize > fatlength) getsize = fatlength;
233 		if (disk_read(startblock, getsize, bufptr) < 0) {
234 			FAT_DPRINT("Error reading FAT blocks\n");
235 			return ret;
236 		}
237 		mydata->fatbufnum = bufnum;
238 	}
239 
240 	/* Get the actual entry from the table */
241 	switch (mydata->fatsize) {
242 	case 32:
243 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
244 		break;
245 	case 16:
246 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
247 		break;
248 	case 12: {
249 		__u32 off16 = (offset*3)/4;
250 		__u16 val1, val2;
251 
252 		switch (offset & 0x3) {
253 		case 0:
254 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
255 			ret &= 0xfff;
256 			break;
257 		case 1:
258 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
259 			val1 &= 0xf000;
260 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
261 			val2 &= 0x00ff;
262 			ret = (val2 << 4) | (val1 >> 12);
263 			break;
264 		case 2:
265 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
266 			val1 &= 0xff00;
267 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
268 			val2 &= 0x000f;
269 			ret = (val2 << 8) | (val1 >> 8);
270 			break;
271 		case 3:
272 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
273 			ret = (ret & 0xfff0) >> 4;
274 			break;
275 		default:
276 			break;
277 		}
278 	}
279 	break;
280 	}
281 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
282 
283 	return ret;
284 }
285 
286 
287 /*
288  * Read at most 'size' bytes from the specified cluster into 'buffer'.
289  * Return 0 on success, -1 otherwise.
290  */
291 static int
292 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
293 {
294 	int idx = 0;
295 	__u32 startsect;
296 
297 	if (clustnum > 0) {
298 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
299 	} else {
300 		startsect = mydata->rootdir_sect;
301 	}
302 
303 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
304 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
305 		FAT_DPRINT("Error reading data\n");
306 		return -1;
307 	}
308 	if(size % FS_BLOCK_SIZE) {
309 		__u8 tmpbuf[FS_BLOCK_SIZE];
310 		idx= size/FS_BLOCK_SIZE;
311 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
312 			FAT_DPRINT("Error reading data\n");
313 			return -1;
314 		}
315 		buffer += idx*FS_BLOCK_SIZE;
316 
317 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
318 		return 0;
319 	}
320 
321 	return 0;
322 }
323 
324 
325 /*
326  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
327  * into 'buffer'.
328  * Return the number of bytes read or -1 on fatal errors.
329  */
330 static long
331 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
332 	     unsigned long maxsize)
333 {
334 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
335 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
336 	__u32 curclust = START(dentptr);
337 	__u32 endclust, newclust;
338 	unsigned long actsize;
339 
340 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
341 
342 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
343 
344 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
345 
346 	actsize=bytesperclust;
347 	endclust=curclust;
348 	do {
349 		/* search for consecutive clusters */
350 		while(actsize < filesize) {
351 			newclust = get_fatent(mydata, endclust);
352 			if((newclust -1)!=endclust)
353 				goto getit;
354 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
355 				FAT_DPRINT("curclust: 0x%x\n", newclust);
356 				FAT_DPRINT("Invalid FAT entry\n");
357 				return gotsize;
358 			}
359 			endclust=newclust;
360 			actsize+= bytesperclust;
361 		}
362 		/* actsize >= file size */
363 		actsize -= bytesperclust;
364 		/* get remaining clusters */
365 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
366 			FAT_ERROR("Error reading cluster\n");
367 			return -1;
368 		}
369 		/* get remaining bytes */
370 		gotsize += (int)actsize;
371 		filesize -= actsize;
372 		buffer += actsize;
373 		actsize= filesize;
374 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
375 			FAT_ERROR("Error reading cluster\n");
376 			return -1;
377 		}
378 		gotsize+=actsize;
379 		return gotsize;
380 getit:
381 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
382 			FAT_ERROR("Error reading cluster\n");
383 			return -1;
384 		}
385 		gotsize += (int)actsize;
386 		filesize -= actsize;
387 		buffer += actsize;
388 		curclust = get_fatent(mydata, endclust);
389 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
390 			FAT_DPRINT("curclust: 0x%x\n", curclust);
391 			FAT_ERROR("Invalid FAT entry\n");
392 			return gotsize;
393 		}
394 		actsize=bytesperclust;
395 		endclust=curclust;
396 	} while (1);
397 }
398 
399 
400 #ifdef CONFIG_SUPPORT_VFAT
401 /*
402  * Extract the file name information from 'slotptr' into 'l_name',
403  * starting at l_name[*idx].
404  * Return 1 if terminator (zero byte) is found, 0 otherwise.
405  */
406 static int
407 slot2str(dir_slot *slotptr, char *l_name, int *idx)
408 {
409 	int j;
410 
411 	for (j = 0; j <= 8; j += 2) {
412 		l_name[*idx] = slotptr->name0_4[j];
413 		if (l_name[*idx] == 0x00) return 1;
414 		(*idx)++;
415 	}
416 	for (j = 0; j <= 10; j += 2) {
417 		l_name[*idx] = slotptr->name5_10[j];
418 		if (l_name[*idx] == 0x00) return 1;
419 		(*idx)++;
420 	}
421 	for (j = 0; j <= 2; j += 2) {
422 		l_name[*idx] = slotptr->name11_12[j];
423 		if (l_name[*idx] == 0x00) return 1;
424 		(*idx)++;
425 	}
426 
427 	return 0;
428 }
429 
430 
431 /*
432  * Extract the full long filename starting at 'retdent' (which is really
433  * a slot) into 'l_name'. If successful also copy the real directory entry
434  * into 'retdent'
435  * Return 0 on success, -1 otherwise.
436  */
437 __attribute__ ((__aligned__(__alignof__(dir_entry))))
438 __u8 get_vfatname_block[MAX_CLUSTSIZE];
439 static int
440 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
441 	     dir_entry *retdent, char *l_name)
442 {
443 	dir_entry *realdent;
444 	dir_slot  *slotptr = (dir_slot*) retdent;
445 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
446 	__u8	   counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
447 	int idx = 0;
448 
449 	while ((__u8*)slotptr < nextclust) {
450 		if (counter == 0) break;
451 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
452 			return -1;
453 		slotptr++;
454 		counter--;
455 	}
456 
457 	if ((__u8*)slotptr >= nextclust) {
458 		dir_slot *slotptr2;
459 
460 		slotptr--;
461 		curclust = get_fatent(mydata, curclust);
462 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
463 			FAT_DPRINT("curclust: 0x%x\n", curclust);
464 			FAT_ERROR("Invalid FAT entry\n");
465 			return -1;
466 		}
467 		if (get_cluster(mydata, curclust, get_vfatname_block,
468 				mydata->clust_size * SECTOR_SIZE) != 0) {
469 			FAT_DPRINT("Error: reading directory block\n");
470 			return -1;
471 		}
472 		slotptr2 = (dir_slot*) get_vfatname_block;
473 		while (slotptr2->id > 0x01) {
474 			slotptr2++;
475 		}
476 		/* Save the real directory entry */
477 		realdent = (dir_entry*)slotptr2 + 1;
478 		while ((__u8*)slotptr2 >= get_vfatname_block) {
479 			slot2str(slotptr2, l_name, &idx);
480 			slotptr2--;
481 		}
482 	} else {
483 		/* Save the real directory entry */
484 		realdent = (dir_entry*)slotptr;
485 	}
486 
487 	do {
488 		slotptr--;
489 		if (slot2str(slotptr, l_name, &idx)) break;
490 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
491 
492 	l_name[idx] = '\0';
493 	if (*l_name == DELETED_FLAG) *l_name = '\0';
494 	else if (*l_name == aRING) *l_name = DELETED_FLAG;
495 	downcase(l_name);
496 
497 	/* Return the real directory entry */
498 	memcpy(retdent, realdent, sizeof(dir_entry));
499 
500 	return 0;
501 }
502 
503 
504 /* Calculate short name checksum */
505 static __u8
506 mkcksum(const char *str)
507 {
508 	int i;
509 	__u8 ret = 0;
510 
511 	for (i = 0; i < 11; i++) {
512 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
513 	}
514 
515 	return ret;
516 }
517 #endif
518 
519 
520 /*
521  * Get the directory entry associated with 'filename' from the directory
522  * starting at 'startsect'
523  */
524 __attribute__ ((__aligned__(__alignof__(dir_entry))))
525 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
526 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
527 				   char *filename, dir_entry * retdent,
528 				   int dols)
529 {
530     __u16 prevcksum = 0xffff;
531     __u32 curclust = START (retdent);
532     int files = 0, dirs = 0;
533 
534     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
535     while (1) {
536 	dir_entry *dentptr;
537 	int i;
538 
539 	if (get_cluster (mydata, curclust, get_dentfromdir_block,
540 		 mydata->clust_size * SECTOR_SIZE) != 0) {
541 	    FAT_DPRINT ("Error: reading directory block\n");
542 	    return NULL;
543 	}
544 	dentptr = (dir_entry *) get_dentfromdir_block;
545 	for (i = 0; i < DIRENTSPERCLUST; i++) {
546 	    char s_name[14], l_name[256];
547 
548 	    l_name[0] = '\0';
549 	    if (dentptr->name[0] == DELETED_FLAG) {
550 		    dentptr++;
551 		    continue;
552 	    }
553 	    if ((dentptr->attr & ATTR_VOLUME)) {
554 #ifdef CONFIG_SUPPORT_VFAT
555 		if ((dentptr->attr & ATTR_VFAT) &&
556 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
557 		    prevcksum = ((dir_slot *) dentptr)
558 			    ->alias_checksum;
559 		    get_vfatname (mydata, curclust, get_dentfromdir_block,
560 				  dentptr, l_name);
561 		    if (dols) {
562 			int isdir = (dentptr->attr & ATTR_DIR);
563 			char dirc;
564 			int doit = 0;
565 
566 			if (isdir) {
567 			    dirs++;
568 			    dirc = '/';
569 			    doit = 1;
570 			} else {
571 			    dirc = ' ';
572 			    if (l_name[0] != 0) {
573 				files++;
574 				doit = 1;
575 			    }
576 			}
577 			if (doit) {
578 			    if (dirc == ' ') {
579 				printf (" %8ld   %s%c\n",
580 					(long) FAT2CPU32 (dentptr->size),
581 					l_name, dirc);
582 			    } else {
583 				printf ("            %s%c\n", l_name, dirc);
584 			    }
585 			}
586 			dentptr++;
587 			continue;
588 		    }
589 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
590 		} else
591 #endif
592 		{
593 		    /* Volume label or VFAT entry */
594 		    dentptr++;
595 		    continue;
596 		}
597 	    }
598 	    if (dentptr->name[0] == 0) {
599 		if (dols) {
600 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
601 		}
602 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
603 		return NULL;
604 	    }
605 #ifdef CONFIG_SUPPORT_VFAT
606 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
607 		dentptr++;
608 		continue;
609 	    }
610 #endif
611 	    get_name (dentptr, s_name);
612 	    if (dols) {
613 		int isdir = (dentptr->attr & ATTR_DIR);
614 		char dirc;
615 		int doit = 0;
616 
617 		if (isdir) {
618 		    dirs++;
619 		    dirc = '/';
620 		    doit = 1;
621 		} else {
622 		    dirc = ' ';
623 		    if (s_name[0] != 0) {
624 			files++;
625 			doit = 1;
626 		    }
627 		}
628 		if (doit) {
629 		    if (dirc == ' ') {
630 			printf (" %8ld   %s%c\n",
631 				(long) FAT2CPU32 (dentptr->size), s_name,
632 				dirc);
633 		    } else {
634 			printf ("            %s%c\n", s_name, dirc);
635 		    }
636 		}
637 		dentptr++;
638 		continue;
639 	    }
640 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
641 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
642 		dentptr++;
643 		continue;
644 	    }
645 	    memcpy (retdent, dentptr, sizeof (dir_entry));
646 
647 	    FAT_DPRINT ("DentName: %s", s_name);
648 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
649 	    FAT_DPRINT (", size:  0x%x %s\n",
650 			FAT2CPU32 (dentptr->size),
651 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
652 
653 	    return retdent;
654 	}
655 	curclust = get_fatent (mydata, curclust);
656 	if (CHECK_CLUST(curclust, mydata->fatsize)) {
657 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
658 	    FAT_ERROR ("Invalid FAT entry\n");
659 	    return NULL;
660 	}
661     }
662 
663     return NULL;
664 }
665 
666 
667 /*
668  * Read boot sector and volume info from a FAT filesystem
669  */
670 static int
671 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
672 {
673 	__u8 block[FS_BLOCK_SIZE];
674 	volume_info *vistart;
675 
676 	if (disk_read(0, 1, block) < 0) {
677 		FAT_DPRINT("Error: reading block\n");
678 		return -1;
679 	}
680 
681 	memcpy(bs, block, sizeof(boot_sector));
682 	bs->reserved	= FAT2CPU16(bs->reserved);
683 	bs->fat_length	= FAT2CPU16(bs->fat_length);
684 	bs->secs_track	= FAT2CPU16(bs->secs_track);
685 	bs->heads	= FAT2CPU16(bs->heads);
686 #if 0 /* UNUSED */
687 	bs->hidden	= FAT2CPU32(bs->hidden);
688 #endif
689 	bs->total_sect	= FAT2CPU32(bs->total_sect);
690 
691 	/* FAT32 entries */
692 	if (bs->fat_length == 0) {
693 		/* Assume FAT32 */
694 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
695 		bs->flags	 = FAT2CPU16(bs->flags);
696 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
697 		bs->info_sector  = FAT2CPU16(bs->info_sector);
698 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
699 		vistart = (volume_info*) (block + sizeof(boot_sector));
700 		*fatsize = 32;
701 	} else {
702 		vistart = (volume_info*) &(bs->fat32_length);
703 		*fatsize = 0;
704 	}
705 	memcpy(volinfo, vistart, sizeof(volume_info));
706 
707 	/* Terminate fs_type string. Writing past the end of vistart
708 	   is ok - it's just the buffer. */
709 	vistart->fs_type[8] = '\0';
710 
711 	if (*fatsize == 32) {
712 		if (compare_sign(FAT32_SIGN, vistart->fs_type) == 0) {
713 			return 0;
714 		}
715 	} else {
716 		if (compare_sign(FAT12_SIGN, vistart->fs_type) == 0) {
717 			*fatsize = 12;
718 			return 0;
719 		}
720 		if (compare_sign(FAT16_SIGN, vistart->fs_type) == 0) {
721 			*fatsize = 16;
722 			return 0;
723 		}
724 	}
725 
726 	FAT_DPRINT("Error: broken fs_type sign\n");
727 	return -1;
728 }
729 
730 __attribute__ ((__aligned__(__alignof__(dir_entry))))
731 __u8 do_fat_read_block[MAX_CLUSTSIZE];
732 long
733 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
734 	     int dols)
735 {
736 #if CONFIG_NIOS /* NIOS CPU cannot access big automatic arrays */
737     static
738 #endif
739     char fnamecopy[2048];
740     boot_sector bs;
741     volume_info volinfo;
742     fsdata datablock;
743     fsdata *mydata = &datablock;
744     dir_entry *dentptr;
745     __u16 prevcksum = 0xffff;
746     char *subname = "";
747     int rootdir_size, cursect;
748     int idx, isdir = 0;
749     int files = 0, dirs = 0;
750     long ret = 0;
751     int firsttime;
752 
753     if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
754 	FAT_DPRINT ("Error: reading boot sector\n");
755 	return -1;
756     }
757     if (mydata->fatsize == 32) {
758 	mydata->fatlength = bs.fat32_length;
759     } else {
760 	mydata->fatlength = bs.fat_length;
761     }
762     mydata->fat_sect = bs.reserved;
763     cursect = mydata->rootdir_sect
764 	    = mydata->fat_sect + mydata->fatlength * bs.fats;
765     mydata->clust_size = bs.cluster_size;
766     if (mydata->fatsize == 32) {
767 	rootdir_size = mydata->clust_size;
768 	mydata->data_begin = mydata->rootdir_sect   /* + rootdir_size */
769 		- (mydata->clust_size * 2);
770     } else {
771 	rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
772 			* sizeof (dir_entry)) / SECTOR_SIZE;
773 	mydata->data_begin = mydata->rootdir_sect + rootdir_size
774 		- (mydata->clust_size * 2);
775     }
776     mydata->fatbufnum = -1;
777 
778     FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
779 		mydata->fatlength);
780     FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
781 		"Data begins at: %d\n",
782 		mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
783 		rootdir_size, mydata->data_begin);
784     FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
785 
786     /* "cwd" is always the root... */
787     while (ISDIRDELIM (*filename))
788 	filename++;
789     /* Make a copy of the filename and convert it to lowercase */
790     strcpy (fnamecopy, filename);
791     downcase (fnamecopy);
792     if (*fnamecopy == '\0') {
793 	if (!dols)
794 	    return -1;
795 	dols = LS_ROOT;
796     } else if ((idx = dirdelim (fnamecopy)) >= 0) {
797 	isdir = 1;
798 	fnamecopy[idx] = '\0';
799 	subname = fnamecopy + idx + 1;
800 	/* Handle multiple delimiters */
801 	while (ISDIRDELIM (*subname))
802 	    subname++;
803     } else if (dols) {
804 	isdir = 1;
805     }
806 
807     while (1) {
808 	int i;
809 
810 	if (disk_read (cursect, mydata->clust_size, do_fat_read_block) < 0) {
811 	    FAT_DPRINT ("Error: reading rootdir block\n");
812 	    return -1;
813 	}
814 	dentptr = (dir_entry *) do_fat_read_block;
815 	for (i = 0; i < DIRENTSPERBLOCK; i++) {
816 	    char s_name[14], l_name[256];
817 
818 	    l_name[0] = '\0';
819 	    if ((dentptr->attr & ATTR_VOLUME)) {
820 #ifdef CONFIG_SUPPORT_VFAT
821 		if ((dentptr->attr & ATTR_VFAT) &&
822 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
823 		    prevcksum = ((dir_slot *) dentptr)->alias_checksum;
824 		    get_vfatname (mydata, 0, do_fat_read_block, dentptr, l_name);
825 		    if (dols == LS_ROOT) {
826 			int isdir = (dentptr->attr & ATTR_DIR);
827 			char dirc;
828 			int doit = 0;
829 
830 			if (isdir) {
831 			    dirs++;
832 			    dirc = '/';
833 			    doit = 1;
834 			} else {
835 			    dirc = ' ';
836 			    if (l_name[0] != 0) {
837 				files++;
838 				doit = 1;
839 			    }
840 			}
841 			if (doit) {
842 			    if (dirc == ' ') {
843 				printf (" %8ld   %s%c\n",
844 					(long) FAT2CPU32 (dentptr->size),
845 					l_name, dirc);
846 			    } else {
847 				printf ("            %s%c\n", l_name, dirc);
848 			    }
849 			}
850 			dentptr++;
851 			continue;
852 		    }
853 		    FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
854 		} else
855 #endif
856 		{
857 		    /* Volume label or VFAT entry */
858 		    dentptr++;
859 		    continue;
860 		}
861 	    } else if (dentptr->name[0] == 0) {
862 		FAT_DPRINT ("RootDentname == NULL - %d\n", i);
863 		if (dols == LS_ROOT) {
864 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
865 		    return 0;
866 		}
867 		return -1;
868 	    }
869 #ifdef CONFIG_SUPPORT_VFAT
870 	    else if (dols == LS_ROOT
871 		     && mkcksum (dentptr->name) == prevcksum) {
872 		dentptr++;
873 		continue;
874 	    }
875 #endif
876 	    get_name (dentptr, s_name);
877 	    if (dols == LS_ROOT) {
878 		int isdir = (dentptr->attr & ATTR_DIR);
879 		char dirc;
880 		int doit = 0;
881 
882 		if (isdir) {
883 		    dirc = '/';
884 		    if (s_name[0] != 0) {
885 			dirs++;
886 			doit = 1;
887 		    }
888 		} else {
889 		    dirc = ' ';
890 		    if (s_name[0] != 0) {
891 			files++;
892 			doit = 1;
893 		    }
894 		}
895 		if (doit) {
896 		    if (dirc == ' ') {
897 			printf (" %8ld   %s%c\n",
898 				(long) FAT2CPU32 (dentptr->size), s_name,
899 				dirc);
900 		    } else {
901 			printf ("            %s%c\n", s_name, dirc);
902 		    }
903 		}
904 		dentptr++;
905 		continue;
906 	    }
907 	    if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
908 		FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
909 		dentptr++;
910 		continue;
911 	    }
912 	    if (isdir && !(dentptr->attr & ATTR_DIR))
913 		return -1;
914 
915 	    FAT_DPRINT ("RootName: %s", s_name);
916 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
917 	    FAT_DPRINT (", size:  0x%x %s\n",
918 			FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
919 
920 	    goto rootdir_done;  /* We got a match */
921 	}
922 	cursect++;
923     }
924   rootdir_done:
925 
926     firsttime = 1;
927     while (isdir) {
928 	int startsect = mydata->data_begin
929 		+ START (dentptr) * mydata->clust_size;
930 	dir_entry dent;
931 	char *nextname = NULL;
932 
933 	dent = *dentptr;
934 	dentptr = &dent;
935 
936 	idx = dirdelim (subname);
937 	if (idx >= 0) {
938 	    subname[idx] = '\0';
939 	    nextname = subname + idx + 1;
940 	    /* Handle multiple delimiters */
941 	    while (ISDIRDELIM (*nextname))
942 		nextname++;
943 	    if (dols && *nextname == '\0')
944 		firsttime = 0;
945 	} else {
946 	    if (dols && firsttime) {
947 		firsttime = 0;
948 	    } else {
949 		isdir = 0;
950 	    }
951 	}
952 
953 	if (get_dentfromdir (mydata, startsect, subname, dentptr,
954 			     isdir ? 0 : dols) == NULL) {
955 	    if (dols && !isdir)
956 		return 0;
957 	    return -1;
958 	}
959 
960 	if (idx >= 0) {
961 	    if (!(dentptr->attr & ATTR_DIR))
962 		return -1;
963 	    subname = nextname;
964 	}
965     }
966     ret = get_contents (mydata, dentptr, buffer, maxsize);
967     FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
968 
969     return ret;
970 }
971 
972 
973 int
974 file_fat_detectfs(void)
975 {
976 	boot_sector	bs;
977 	volume_info	volinfo;
978 	int		fatsize;
979 	char	vol_label[12];
980 
981 	if(cur_dev==NULL) {
982 		printf("No current device\n");
983 		return 1;
984 	}
985 #if defined(CONFIG_CMD_IDE) || \
986     defined(CONFIG_CMD_SATA) || \
987     defined(CONFIG_CMD_SCSI) || \
988     defined(CONFIG_CMD_USB) || \
989     defined(CONFIG_MMC)
990 	printf("Interface:  ");
991 	switch(cur_dev->if_type) {
992 		case IF_TYPE_IDE :	printf("IDE"); break;
993 		case IF_TYPE_SATA :	printf("SATA"); break;
994 		case IF_TYPE_SCSI :	printf("SCSI"); break;
995 		case IF_TYPE_ATAPI :	printf("ATAPI"); break;
996 		case IF_TYPE_USB :	printf("USB"); break;
997 		case IF_TYPE_DOC :	printf("DOC"); break;
998 		case IF_TYPE_MMC :	printf("MMC"); break;
999 		default :		printf("Unknown");
1000 	}
1001 	printf("\n  Device %d: ",cur_dev->dev);
1002 	dev_print(cur_dev);
1003 #endif
1004 	if(read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1005 		printf("\nNo valid FAT fs found\n");
1006 		return 1;
1007 	}
1008 	memcpy (vol_label, volinfo.volume_label, 11);
1009 	vol_label[11] = '\0';
1010 	volinfo.fs_type[5]='\0';
1011 	printf("Partition %d: Filesystem: %s \"%s\"\n"
1012 			,cur_part,volinfo.fs_type,vol_label);
1013 	return 0;
1014 }
1015 
1016 
1017 int
1018 file_fat_ls(const char *dir)
1019 {
1020 	return do_fat_read(dir, NULL, 0, LS_YES);
1021 }
1022 
1023 
1024 long
1025 file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1026 {
1027 	printf("reading %s\n",filename);
1028 	return do_fat_read(filename, buffer, maxsize, LS_NO);
1029 }
1030