xref: /openbmc/u-boot/fs/fat/fat.c (revision 33b1d3f4)
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  * Extract zero terminated short name from a directory entry.
145  */
146 static void get_name (dir_entry *dirent, char *s_name)
147 {
148 	char *ptr;
149 
150 	memcpy (s_name, dirent->name, 8);
151 	s_name[8] = '\0';
152 	ptr = s_name;
153 	while (*ptr && *ptr != ' ')
154 		ptr++;
155 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
156 		*ptr = '.';
157 		ptr++;
158 		memcpy (ptr, dirent->ext, 3);
159 		ptr[3] = '\0';
160 		while (*ptr && *ptr != ' ')
161 			ptr++;
162 	}
163 	*ptr = '\0';
164 	if (*s_name == DELETED_FLAG)
165 		*s_name = '\0';
166 	else if (*s_name == aRING)
167 		*s_name = DELETED_FLAG;
168 	downcase (s_name);
169 }
170 
171 /*
172  * Get the entry at index 'entry' in a FAT (12/16/32) table.
173  * On failure 0x00 is returned.
174  */
175 static __u32
176 get_fatent(fsdata *mydata, __u32 entry)
177 {
178 	__u32 bufnum;
179 	__u32 offset;
180 	__u32 ret = 0x00;
181 
182 	switch (mydata->fatsize) {
183 	case 32:
184 		bufnum = entry / FAT32BUFSIZE;
185 		offset = entry - bufnum * FAT32BUFSIZE;
186 		break;
187 	case 16:
188 		bufnum = entry / FAT16BUFSIZE;
189 		offset = entry - bufnum * FAT16BUFSIZE;
190 		break;
191 	case 12:
192 		bufnum = entry / FAT12BUFSIZE;
193 		offset = entry - bufnum * FAT12BUFSIZE;
194 		break;
195 
196 	default:
197 		/* Unsupported FAT size */
198 		return ret;
199 	}
200 
201 	/* Read a new block of FAT entries into the cache. */
202 	if (bufnum != mydata->fatbufnum) {
203 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
204 		__u8 *bufptr = mydata->fatbuf;
205 		__u32 fatlength = mydata->fatlength;
206 		__u32 startblock = bufnum * FATBUFBLOCKS;
207 
208 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
209 		startblock += mydata->fat_sect;	/* Offset from start of disk */
210 
211 		if (getsize > fatlength) getsize = fatlength;
212 		if (disk_read(startblock, getsize, bufptr) < 0) {
213 			FAT_DPRINT("Error reading FAT blocks\n");
214 			return ret;
215 		}
216 		mydata->fatbufnum = bufnum;
217 	}
218 
219 	/* Get the actual entry from the table */
220 	switch (mydata->fatsize) {
221 	case 32:
222 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
223 		break;
224 	case 16:
225 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
226 		break;
227 	case 12: {
228 		__u32 off16 = (offset*3)/4;
229 		__u16 val1, val2;
230 
231 		switch (offset & 0x3) {
232 		case 0:
233 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
234 			ret &= 0xfff;
235 			break;
236 		case 1:
237 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
238 			val1 &= 0xf000;
239 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
240 			val2 &= 0x00ff;
241 			ret = (val2 << 4) | (val1 >> 12);
242 			break;
243 		case 2:
244 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
245 			val1 &= 0xff00;
246 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
247 			val2 &= 0x000f;
248 			ret = (val2 << 8) | (val1 >> 8);
249 			break;
250 		case 3:
251 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
252 			ret = (ret & 0xfff0) >> 4;
253 			break;
254 		default:
255 			break;
256 		}
257 	}
258 	break;
259 	}
260 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
261 
262 	return ret;
263 }
264 
265 
266 /*
267  * Read at most 'size' bytes from the specified cluster into 'buffer'.
268  * Return 0 on success, -1 otherwise.
269  */
270 static int
271 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
272 {
273 	int idx = 0;
274 	__u32 startsect;
275 
276 	if (clustnum > 0) {
277 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
278 	} else {
279 		startsect = mydata->rootdir_sect;
280 	}
281 
282 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
283 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
284 		FAT_DPRINT("Error reading data\n");
285 		return -1;
286 	}
287 	if(size % FS_BLOCK_SIZE) {
288 		__u8 tmpbuf[FS_BLOCK_SIZE];
289 		idx= size/FS_BLOCK_SIZE;
290 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
291 			FAT_DPRINT("Error reading data\n");
292 			return -1;
293 		}
294 		buffer += idx*FS_BLOCK_SIZE;
295 
296 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
297 		return 0;
298 	}
299 
300 	return 0;
301 }
302 
303 
304 /*
305  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
306  * into 'buffer'.
307  * Return the number of bytes read or -1 on fatal errors.
308  */
309 static long
310 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
311 	     unsigned long maxsize)
312 {
313 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
314 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
315 	__u32 curclust = START(dentptr);
316 	__u32 endclust, newclust;
317 	unsigned long actsize;
318 
319 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
320 
321 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
322 
323 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
324 
325 	actsize=bytesperclust;
326 	endclust=curclust;
327 	do {
328 		/* search for consecutive clusters */
329 		while(actsize < filesize) {
330 			newclust = get_fatent(mydata, endclust);
331 			if((newclust -1)!=endclust)
332 				goto getit;
333 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
334 				FAT_DPRINT("curclust: 0x%x\n", newclust);
335 				FAT_DPRINT("Invalid FAT entry\n");
336 				return gotsize;
337 			}
338 			endclust=newclust;
339 			actsize+= bytesperclust;
340 		}
341 		/* actsize >= file size */
342 		actsize -= bytesperclust;
343 		/* get remaining clusters */
344 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
345 			FAT_ERROR("Error reading cluster\n");
346 			return -1;
347 		}
348 		/* get remaining bytes */
349 		gotsize += (int)actsize;
350 		filesize -= actsize;
351 		buffer += actsize;
352 		actsize= filesize;
353 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
354 			FAT_ERROR("Error reading cluster\n");
355 			return -1;
356 		}
357 		gotsize+=actsize;
358 		return gotsize;
359 getit:
360 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
361 			FAT_ERROR("Error reading cluster\n");
362 			return -1;
363 		}
364 		gotsize += (int)actsize;
365 		filesize -= actsize;
366 		buffer += actsize;
367 		curclust = get_fatent(mydata, endclust);
368 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
369 			FAT_DPRINT("curclust: 0x%x\n", curclust);
370 			FAT_ERROR("Invalid FAT entry\n");
371 			return gotsize;
372 		}
373 		actsize=bytesperclust;
374 		endclust=curclust;
375 	} while (1);
376 }
377 
378 
379 #ifdef CONFIG_SUPPORT_VFAT
380 /*
381  * Extract the file name information from 'slotptr' into 'l_name',
382  * starting at l_name[*idx].
383  * Return 1 if terminator (zero byte) is found, 0 otherwise.
384  */
385 static int
386 slot2str(dir_slot *slotptr, char *l_name, int *idx)
387 {
388 	int j;
389 
390 	for (j = 0; j <= 8; j += 2) {
391 		l_name[*idx] = slotptr->name0_4[j];
392 		if (l_name[*idx] == 0x00) return 1;
393 		(*idx)++;
394 	}
395 	for (j = 0; j <= 10; j += 2) {
396 		l_name[*idx] = slotptr->name5_10[j];
397 		if (l_name[*idx] == 0x00) return 1;
398 		(*idx)++;
399 	}
400 	for (j = 0; j <= 2; j += 2) {
401 		l_name[*idx] = slotptr->name11_12[j];
402 		if (l_name[*idx] == 0x00) return 1;
403 		(*idx)++;
404 	}
405 
406 	return 0;
407 }
408 
409 
410 /*
411  * Extract the full long filename starting at 'retdent' (which is really
412  * a slot) into 'l_name'. If successful also copy the real directory entry
413  * into 'retdent'
414  * Return 0 on success, -1 otherwise.
415  */
416 __attribute__ ((__aligned__(__alignof__(dir_entry))))
417 __u8 get_vfatname_block[MAX_CLUSTSIZE];
418 static int
419 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
420 	     dir_entry *retdent, char *l_name)
421 {
422 	dir_entry *realdent;
423 	dir_slot  *slotptr = (dir_slot*) retdent;
424 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
425 	__u8	   counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
426 	int idx = 0;
427 
428 	while ((__u8*)slotptr < nextclust) {
429 		if (counter == 0) break;
430 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
431 			return -1;
432 		slotptr++;
433 		counter--;
434 	}
435 
436 	if ((__u8*)slotptr >= nextclust) {
437 		dir_slot *slotptr2;
438 
439 		slotptr--;
440 		curclust = get_fatent(mydata, curclust);
441 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
442 			FAT_DPRINT("curclust: 0x%x\n", curclust);
443 			FAT_ERROR("Invalid FAT entry\n");
444 			return -1;
445 		}
446 		if (get_cluster(mydata, curclust, get_vfatname_block,
447 				mydata->clust_size * SECTOR_SIZE) != 0) {
448 			FAT_DPRINT("Error: reading directory block\n");
449 			return -1;
450 		}
451 		slotptr2 = (dir_slot*) get_vfatname_block;
452 		while (slotptr2->id > 0x01) {
453 			slotptr2++;
454 		}
455 		/* Save the real directory entry */
456 		realdent = (dir_entry*)slotptr2 + 1;
457 		while ((__u8*)slotptr2 >= get_vfatname_block) {
458 			slot2str(slotptr2, l_name, &idx);
459 			slotptr2--;
460 		}
461 	} else {
462 		/* Save the real directory entry */
463 		realdent = (dir_entry*)slotptr;
464 	}
465 
466 	do {
467 		slotptr--;
468 		if (slot2str(slotptr, l_name, &idx)) break;
469 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
470 
471 	l_name[idx] = '\0';
472 	if (*l_name == DELETED_FLAG) *l_name = '\0';
473 	else if (*l_name == aRING) *l_name = DELETED_FLAG;
474 	downcase(l_name);
475 
476 	/* Return the real directory entry */
477 	memcpy(retdent, realdent, sizeof(dir_entry));
478 
479 	return 0;
480 }
481 
482 
483 /* Calculate short name checksum */
484 static __u8
485 mkcksum(const char *str)
486 {
487 	int i;
488 	__u8 ret = 0;
489 
490 	for (i = 0; i < 11; i++) {
491 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
492 	}
493 
494 	return ret;
495 }
496 #endif
497 
498 
499 /*
500  * Get the directory entry associated with 'filename' from the directory
501  * starting at 'startsect'
502  */
503 __attribute__ ((__aligned__(__alignof__(dir_entry))))
504 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
505 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
506 				   char *filename, dir_entry * retdent,
507 				   int dols)
508 {
509     __u16 prevcksum = 0xffff;
510     __u32 curclust = START (retdent);
511     int files = 0, dirs = 0;
512 
513     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
514     while (1) {
515 	dir_entry *dentptr;
516 	int i;
517 
518 	if (get_cluster (mydata, curclust, get_dentfromdir_block,
519 		 mydata->clust_size * SECTOR_SIZE) != 0) {
520 	    FAT_DPRINT ("Error: reading directory block\n");
521 	    return NULL;
522 	}
523 	dentptr = (dir_entry *) get_dentfromdir_block;
524 	for (i = 0; i < DIRENTSPERCLUST; i++) {
525 	    char s_name[14], l_name[256];
526 
527 	    l_name[0] = '\0';
528 	    if (dentptr->name[0] == DELETED_FLAG) {
529 		    dentptr++;
530 		    continue;
531 	    }
532 	    if ((dentptr->attr & ATTR_VOLUME)) {
533 #ifdef CONFIG_SUPPORT_VFAT
534 		if ((dentptr->attr & ATTR_VFAT) &&
535 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
536 		    prevcksum = ((dir_slot *) dentptr)
537 			    ->alias_checksum;
538 		    get_vfatname (mydata, curclust, get_dentfromdir_block,
539 				  dentptr, l_name);
540 		    if (dols) {
541 			int isdir = (dentptr->attr & ATTR_DIR);
542 			char dirc;
543 			int doit = 0;
544 
545 			if (isdir) {
546 			    dirs++;
547 			    dirc = '/';
548 			    doit = 1;
549 			} else {
550 			    dirc = ' ';
551 			    if (l_name[0] != 0) {
552 				files++;
553 				doit = 1;
554 			    }
555 			}
556 			if (doit) {
557 			    if (dirc == ' ') {
558 				printf (" %8ld   %s%c\n",
559 					(long) FAT2CPU32 (dentptr->size),
560 					l_name, dirc);
561 			    } else {
562 				printf ("            %s%c\n", l_name, dirc);
563 			    }
564 			}
565 			dentptr++;
566 			continue;
567 		    }
568 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
569 		} else
570 #endif
571 		{
572 		    /* Volume label or VFAT entry */
573 		    dentptr++;
574 		    continue;
575 		}
576 	    }
577 	    if (dentptr->name[0] == 0) {
578 		if (dols) {
579 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
580 		}
581 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
582 		return NULL;
583 	    }
584 #ifdef CONFIG_SUPPORT_VFAT
585 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
586 		dentptr++;
587 		continue;
588 	    }
589 #endif
590 	    get_name (dentptr, s_name);
591 	    if (dols) {
592 		int isdir = (dentptr->attr & ATTR_DIR);
593 		char dirc;
594 		int doit = 0;
595 
596 		if (isdir) {
597 		    dirs++;
598 		    dirc = '/';
599 		    doit = 1;
600 		} else {
601 		    dirc = ' ';
602 		    if (s_name[0] != 0) {
603 			files++;
604 			doit = 1;
605 		    }
606 		}
607 		if (doit) {
608 		    if (dirc == ' ') {
609 			printf (" %8ld   %s%c\n",
610 				(long) FAT2CPU32 (dentptr->size), s_name,
611 				dirc);
612 		    } else {
613 			printf ("            %s%c\n", s_name, dirc);
614 		    }
615 		}
616 		dentptr++;
617 		continue;
618 	    }
619 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
620 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
621 		dentptr++;
622 		continue;
623 	    }
624 	    memcpy (retdent, dentptr, sizeof (dir_entry));
625 
626 	    FAT_DPRINT ("DentName: %s", s_name);
627 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
628 	    FAT_DPRINT (", size:  0x%x %s\n",
629 			FAT2CPU32 (dentptr->size),
630 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
631 
632 	    return retdent;
633 	}
634 	curclust = get_fatent (mydata, curclust);
635 	if (CHECK_CLUST(curclust, mydata->fatsize)) {
636 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
637 	    FAT_ERROR ("Invalid FAT entry\n");
638 	    return NULL;
639 	}
640     }
641 
642     return NULL;
643 }
644 
645 
646 /*
647  * Read boot sector and volume info from a FAT filesystem
648  */
649 static int
650 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
651 {
652 	__u8 block[FS_BLOCK_SIZE];
653 	volume_info *vistart;
654 
655 	if (disk_read(0, 1, block) < 0) {
656 		FAT_DPRINT("Error: reading block\n");
657 		return -1;
658 	}
659 
660 	memcpy(bs, block, sizeof(boot_sector));
661 	bs->reserved	= FAT2CPU16(bs->reserved);
662 	bs->fat_length	= FAT2CPU16(bs->fat_length);
663 	bs->secs_track	= FAT2CPU16(bs->secs_track);
664 	bs->heads	= FAT2CPU16(bs->heads);
665 #if 0 /* UNUSED */
666 	bs->hidden	= FAT2CPU32(bs->hidden);
667 #endif
668 	bs->total_sect	= FAT2CPU32(bs->total_sect);
669 
670 	/* FAT32 entries */
671 	if (bs->fat_length == 0) {
672 		/* Assume FAT32 */
673 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
674 		bs->flags	 = FAT2CPU16(bs->flags);
675 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
676 		bs->info_sector  = FAT2CPU16(bs->info_sector);
677 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
678 		vistart = (volume_info*) (block + sizeof(boot_sector));
679 		*fatsize = 32;
680 	} else {
681 		vistart = (volume_info*) &(bs->fat32_length);
682 		*fatsize = 0;
683 	}
684 	memcpy(volinfo, vistart, sizeof(volume_info));
685 
686 	if (*fatsize == 32) {
687 		if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0) {
688 			return 0;
689 		}
690 	} else {
691 		if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
692 			*fatsize = 12;
693 			return 0;
694 		}
695 		if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
696 			*fatsize = 16;
697 			return 0;
698 		}
699 	}
700 
701 	FAT_DPRINT("Error: broken fs_type sign\n");
702 	return -1;
703 }
704 
705 __attribute__ ((__aligned__(__alignof__(dir_entry))))
706 __u8 do_fat_read_block[MAX_CLUSTSIZE];
707 long
708 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
709 	     int dols)
710 {
711 #if CONFIG_NIOS /* NIOS CPU cannot access big automatic arrays */
712     static
713 #endif
714     char fnamecopy[2048];
715     boot_sector bs;
716     volume_info volinfo;
717     fsdata datablock;
718     fsdata *mydata = &datablock;
719     dir_entry *dentptr;
720     __u16 prevcksum = 0xffff;
721     char *subname = "";
722     int rootdir_size, cursect;
723     int idx, isdir = 0;
724     int files = 0, dirs = 0;
725     long ret = 0;
726     int firsttime;
727 
728     if (read_bootsectandvi (&bs, &volinfo, &mydata->fatsize)) {
729 	FAT_DPRINT ("Error: reading boot sector\n");
730 	return -1;
731     }
732     if (mydata->fatsize == 32) {
733 	mydata->fatlength = bs.fat32_length;
734     } else {
735 	mydata->fatlength = bs.fat_length;
736     }
737     mydata->fat_sect = bs.reserved;
738     cursect = mydata->rootdir_sect
739 	    = mydata->fat_sect + mydata->fatlength * bs.fats;
740     mydata->clust_size = bs.cluster_size;
741     if (mydata->fatsize == 32) {
742 	rootdir_size = mydata->clust_size;
743 	mydata->data_begin = mydata->rootdir_sect   /* + rootdir_size */
744 		- (mydata->clust_size * 2);
745     } else {
746 	rootdir_size = ((bs.dir_entries[1] * (int) 256 + bs.dir_entries[0])
747 			* sizeof (dir_entry)) / SECTOR_SIZE;
748 	mydata->data_begin = mydata->rootdir_sect + rootdir_size
749 		- (mydata->clust_size * 2);
750     }
751     mydata->fatbufnum = -1;
752 
753     FAT_DPRINT ("FAT%d, fatlength: %d\n", mydata->fatsize,
754 		mydata->fatlength);
755     FAT_DPRINT ("Rootdir begins at sector: %d, offset: %x, size: %d\n"
756 		"Data begins at: %d\n",
757 		mydata->rootdir_sect, mydata->rootdir_sect * SECTOR_SIZE,
758 		rootdir_size, mydata->data_begin);
759     FAT_DPRINT ("Cluster size: %d\n", mydata->clust_size);
760 
761     /* "cwd" is always the root... */
762     while (ISDIRDELIM (*filename))
763 	filename++;
764     /* Make a copy of the filename and convert it to lowercase */
765     strcpy (fnamecopy, filename);
766     downcase (fnamecopy);
767     if (*fnamecopy == '\0') {
768 	if (!dols)
769 	    return -1;
770 	dols = LS_ROOT;
771     } else if ((idx = dirdelim (fnamecopy)) >= 0) {
772 	isdir = 1;
773 	fnamecopy[idx] = '\0';
774 	subname = fnamecopy + idx + 1;
775 	/* Handle multiple delimiters */
776 	while (ISDIRDELIM (*subname))
777 	    subname++;
778     } else if (dols) {
779 	isdir = 1;
780     }
781 
782     while (1) {
783 	int i;
784 
785 	if (disk_read (cursect, mydata->clust_size, do_fat_read_block) < 0) {
786 	    FAT_DPRINT ("Error: reading rootdir block\n");
787 	    return -1;
788 	}
789 	dentptr = (dir_entry *) do_fat_read_block;
790 	for (i = 0; i < DIRENTSPERBLOCK; i++) {
791 	    char s_name[14], l_name[256];
792 
793 	    l_name[0] = '\0';
794 	    if ((dentptr->attr & ATTR_VOLUME)) {
795 #ifdef CONFIG_SUPPORT_VFAT
796 		if ((dentptr->attr & ATTR_VFAT) &&
797 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
798 		    prevcksum = ((dir_slot *) dentptr)->alias_checksum;
799 		    get_vfatname (mydata, 0, do_fat_read_block, dentptr, l_name);
800 		    if (dols == LS_ROOT) {
801 			int isdir = (dentptr->attr & ATTR_DIR);
802 			char dirc;
803 			int doit = 0;
804 
805 			if (isdir) {
806 			    dirs++;
807 			    dirc = '/';
808 			    doit = 1;
809 			} else {
810 			    dirc = ' ';
811 			    if (l_name[0] != 0) {
812 				files++;
813 				doit = 1;
814 			    }
815 			}
816 			if (doit) {
817 			    if (dirc == ' ') {
818 				printf (" %8ld   %s%c\n",
819 					(long) FAT2CPU32 (dentptr->size),
820 					l_name, dirc);
821 			    } else {
822 				printf ("            %s%c\n", l_name, dirc);
823 			    }
824 			}
825 			dentptr++;
826 			continue;
827 		    }
828 		    FAT_DPRINT ("Rootvfatname: |%s|\n", l_name);
829 		} else
830 #endif
831 		{
832 		    /* Volume label or VFAT entry */
833 		    dentptr++;
834 		    continue;
835 		}
836 	    } else if (dentptr->name[0] == 0) {
837 		FAT_DPRINT ("RootDentname == NULL - %d\n", i);
838 		if (dols == LS_ROOT) {
839 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
840 		    return 0;
841 		}
842 		return -1;
843 	    }
844 #ifdef CONFIG_SUPPORT_VFAT
845 	    else if (dols == LS_ROOT
846 		     && mkcksum (dentptr->name) == prevcksum) {
847 		dentptr++;
848 		continue;
849 	    }
850 #endif
851 	    get_name (dentptr, s_name);
852 	    if (dols == LS_ROOT) {
853 		int isdir = (dentptr->attr & ATTR_DIR);
854 		char dirc;
855 		int doit = 0;
856 
857 		if (isdir) {
858 		    dirc = '/';
859 		    if (s_name[0] != 0) {
860 			dirs++;
861 			doit = 1;
862 		    }
863 		} else {
864 		    dirc = ' ';
865 		    if (s_name[0] != 0) {
866 			files++;
867 			doit = 1;
868 		    }
869 		}
870 		if (doit) {
871 		    if (dirc == ' ') {
872 			printf (" %8ld   %s%c\n",
873 				(long) FAT2CPU32 (dentptr->size), s_name,
874 				dirc);
875 		    } else {
876 			printf ("            %s%c\n", s_name, dirc);
877 		    }
878 		}
879 		dentptr++;
880 		continue;
881 	    }
882 	    if (strcmp (fnamecopy, s_name) && strcmp (fnamecopy, l_name)) {
883 		FAT_DPRINT ("RootMismatch: |%s|%s|\n", s_name, l_name);
884 		dentptr++;
885 		continue;
886 	    }
887 	    if (isdir && !(dentptr->attr & ATTR_DIR))
888 		return -1;
889 
890 	    FAT_DPRINT ("RootName: %s", s_name);
891 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
892 	    FAT_DPRINT (", size:  0x%x %s\n",
893 			FAT2CPU32 (dentptr->size), isdir ? "(DIR)" : "");
894 
895 	    goto rootdir_done;  /* We got a match */
896 	}
897 	cursect++;
898     }
899   rootdir_done:
900 
901     firsttime = 1;
902     while (isdir) {
903 	int startsect = mydata->data_begin
904 		+ START (dentptr) * mydata->clust_size;
905 	dir_entry dent;
906 	char *nextname = NULL;
907 
908 	dent = *dentptr;
909 	dentptr = &dent;
910 
911 	idx = dirdelim (subname);
912 	if (idx >= 0) {
913 	    subname[idx] = '\0';
914 	    nextname = subname + idx + 1;
915 	    /* Handle multiple delimiters */
916 	    while (ISDIRDELIM (*nextname))
917 		nextname++;
918 	    if (dols && *nextname == '\0')
919 		firsttime = 0;
920 	} else {
921 	    if (dols && firsttime) {
922 		firsttime = 0;
923 	    } else {
924 		isdir = 0;
925 	    }
926 	}
927 
928 	if (get_dentfromdir (mydata, startsect, subname, dentptr,
929 			     isdir ? 0 : dols) == NULL) {
930 	    if (dols && !isdir)
931 		return 0;
932 	    return -1;
933 	}
934 
935 	if (idx >= 0) {
936 	    if (!(dentptr->attr & ATTR_DIR))
937 		return -1;
938 	    subname = nextname;
939 	}
940     }
941     ret = get_contents (mydata, dentptr, buffer, maxsize);
942     FAT_DPRINT ("Size: %d, got: %ld\n", FAT2CPU32 (dentptr->size), ret);
943 
944     return ret;
945 }
946 
947 
948 int
949 file_fat_detectfs(void)
950 {
951 	boot_sector	bs;
952 	volume_info	volinfo;
953 	int		fatsize;
954 	char	vol_label[12];
955 
956 	if(cur_dev==NULL) {
957 		printf("No current device\n");
958 		return 1;
959 	}
960 #if defined(CONFIG_CMD_IDE) || \
961     defined(CONFIG_CMD_MG_DISK) || \
962     defined(CONFIG_CMD_SATA) || \
963     defined(CONFIG_CMD_SCSI) || \
964     defined(CONFIG_CMD_USB) || \
965     defined(CONFIG_MMC)
966 	printf("Interface:  ");
967 	switch(cur_dev->if_type) {
968 		case IF_TYPE_IDE :	printf("IDE"); break;
969 		case IF_TYPE_SATA :	printf("SATA"); break;
970 		case IF_TYPE_SCSI :	printf("SCSI"); break;
971 		case IF_TYPE_ATAPI :	printf("ATAPI"); break;
972 		case IF_TYPE_USB :	printf("USB"); break;
973 		case IF_TYPE_DOC :	printf("DOC"); break;
974 		case IF_TYPE_MMC :	printf("MMC"); break;
975 		default :		printf("Unknown");
976 	}
977 	printf("\n  Device %d: ",cur_dev->dev);
978 	dev_print(cur_dev);
979 #endif
980 	if(read_bootsectandvi(&bs, &volinfo, &fatsize)) {
981 		printf("\nNo valid FAT fs found\n");
982 		return 1;
983 	}
984 	memcpy (vol_label, volinfo.volume_label, 11);
985 	vol_label[11] = '\0';
986 	volinfo.fs_type[5]='\0';
987 	printf("Partition %d: Filesystem: %s \"%s\"\n"
988 			,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