xref: /rk3399_rockchip-uboot/fs/fat/fat.c (revision 66c2d73cfc901aa35e0331b2fd710b250151f966)
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 #define DOS_FS32_TYPE_OFFSET	0x52
54 
55 int disk_read (__u32 startblock, __u32 getsize, __u8 * bufptr)
56 {
57 	startblock += part_offset;
58 	if (cur_dev == NULL)
59 		return -1;
60 	if (cur_dev->block_read) {
61 		return cur_dev->block_read (cur_dev->dev
62 			, startblock, getsize, (unsigned long *)bufptr);
63 	}
64 	return -1;
65 }
66 
67 
68 int
69 fat_register_device(block_dev_desc_t *dev_desc, int part_no)
70 {
71 	unsigned char buffer[SECTOR_SIZE];
72 	disk_partition_t info;
73 
74 	if (!dev_desc->block_read)
75 		return -1;
76 	cur_dev = dev_desc;
77 	/* check if we have a MBR (on floppies we have only a PBR) */
78 	if (dev_desc->block_read (dev_desc->dev, 0, 1, (ulong *) buffer) != 1) {
79 		printf ("** Can't read from device %d **\n", dev_desc->dev);
80 		return -1;
81 	}
82 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
83 		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
84 		/* no signature found */
85 		return -1;
86 	}
87 #if (defined(CONFIG_CMD_IDE) || \
88      defined(CONFIG_CMD_MG_DISK) || \
89      defined(CONFIG_CMD_SATA) || \
90      defined(CONFIG_CMD_SCSI) || \
91      defined(CONFIG_CMD_USB) || \
92      defined(CONFIG_MMC) || \
93      defined(CONFIG_SYSTEMACE) )
94 	/* First we assume, there is a MBR */
95 	if (!get_partition_info (dev_desc, part_no, &info)) {
96 		part_offset = info.start;
97 		cur_part = part_no;
98 	} else if (strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3)==0 ||
99 		   strncmp((char *)&buffer[DOS_FS32_TYPE_OFFSET],"FAT32",5)==0) {
100 		/* ok, we assume we are on a PBR only */
101 		cur_part = 1;
102 		part_offset = 0;
103 	} else {
104 		printf ("** Partition %d not valid on device %d **\n",
105 				part_no, dev_desc->dev);
106 		return -1;
107 	}
108 
109 #else
110 	if ((strncmp((char *)&buffer[DOS_FS_TYPE_OFFSET], "FAT", 3) == 0) ||
111 	    (strncmp((char *)&buffer[DOS_FS32_TYPE_OFFSET], "FAT32", 5) == 0)) {
112 		/* ok, we assume we are on a PBR only */
113 		cur_part = 1;
114 		part_offset = 0;
115 		info.start = part_offset;
116 	} else {
117 		/* FIXME we need to determine the start block of the
118 		 * partition where the DOS FS resides. This can be done
119 		 * by using the get_partition_info routine. For this
120 		 * purpose the libpart must be included.
121 		 */
122 		part_offset = 32;
123 		cur_part = 1;
124 	}
125 #endif
126 	return 0;
127 }
128 
129 
130 /*
131  * Get the first occurence of a directory delimiter ('/' or '\') in a string.
132  * Return index into string if found, -1 otherwise.
133  */
134 static int
135 dirdelim(char *str)
136 {
137 	char *start = str;
138 
139 	while (*str != '\0') {
140 		if (ISDIRDELIM(*str)) return str - start;
141 		str++;
142 	}
143 	return -1;
144 }
145 
146 /*
147  * Extract zero terminated short name from a directory entry.
148  */
149 static void get_name (dir_entry *dirent, char *s_name)
150 {
151 	char *ptr;
152 
153 	memcpy (s_name, dirent->name, 8);
154 	s_name[8] = '\0';
155 	ptr = s_name;
156 	while (*ptr && *ptr != ' ')
157 		ptr++;
158 	if (dirent->ext[0] && dirent->ext[0] != ' ') {
159 		*ptr = '.';
160 		ptr++;
161 		memcpy (ptr, dirent->ext, 3);
162 		ptr[3] = '\0';
163 		while (*ptr && *ptr != ' ')
164 			ptr++;
165 	}
166 	*ptr = '\0';
167 	if (*s_name == DELETED_FLAG)
168 		*s_name = '\0';
169 	else if (*s_name == aRING)
170 		*s_name = DELETED_FLAG;
171 	downcase (s_name);
172 }
173 
174 /*
175  * Get the entry at index 'entry' in a FAT (12/16/32) table.
176  * On failure 0x00 is returned.
177  */
178 static __u32
179 get_fatent(fsdata *mydata, __u32 entry)
180 {
181 	__u32 bufnum;
182 	__u32 offset;
183 	__u32 ret = 0x00;
184 
185 	switch (mydata->fatsize) {
186 	case 32:
187 		bufnum = entry / FAT32BUFSIZE;
188 		offset = entry - bufnum * FAT32BUFSIZE;
189 		break;
190 	case 16:
191 		bufnum = entry / FAT16BUFSIZE;
192 		offset = entry - bufnum * FAT16BUFSIZE;
193 		break;
194 	case 12:
195 		bufnum = entry / FAT12BUFSIZE;
196 		offset = entry - bufnum * FAT12BUFSIZE;
197 		break;
198 
199 	default:
200 		/* Unsupported FAT size */
201 		return ret;
202 	}
203 
204 	/* Read a new block of FAT entries into the cache. */
205 	if (bufnum != mydata->fatbufnum) {
206 		int getsize = FATBUFSIZE/FS_BLOCK_SIZE;
207 		__u8 *bufptr = mydata->fatbuf;
208 		__u32 fatlength = mydata->fatlength;
209 		__u32 startblock = bufnum * FATBUFBLOCKS;
210 
211 		fatlength *= SECTOR_SIZE;	/* We want it in bytes now */
212 		startblock += mydata->fat_sect;	/* Offset from start of disk */
213 
214 		if (getsize > fatlength) getsize = fatlength;
215 		if (disk_read(startblock, getsize, bufptr) < 0) {
216 			FAT_DPRINT("Error reading FAT blocks\n");
217 			return ret;
218 		}
219 		mydata->fatbufnum = bufnum;
220 	}
221 
222 	/* Get the actual entry from the table */
223 	switch (mydata->fatsize) {
224 	case 32:
225 		ret = FAT2CPU32(((__u32*)mydata->fatbuf)[offset]);
226 		break;
227 	case 16:
228 		ret = FAT2CPU16(((__u16*)mydata->fatbuf)[offset]);
229 		break;
230 	case 12: {
231 		__u32 off16 = (offset*3)/4;
232 		__u16 val1, val2;
233 
234 		switch (offset & 0x3) {
235 		case 0:
236 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
237 			ret &= 0xfff;
238 			break;
239 		case 1:
240 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
241 			val1 &= 0xf000;
242 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
243 			val2 &= 0x00ff;
244 			ret = (val2 << 4) | (val1 >> 12);
245 			break;
246 		case 2:
247 			val1 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);
248 			val1 &= 0xff00;
249 			val2 = FAT2CPU16(((__u16*)mydata->fatbuf)[off16+1]);
250 			val2 &= 0x000f;
251 			ret = (val2 << 8) | (val1 >> 8);
252 			break;
253 		case 3:
254 			ret = FAT2CPU16(((__u16*)mydata->fatbuf)[off16]);;
255 			ret = (ret & 0xfff0) >> 4;
256 			break;
257 		default:
258 			break;
259 		}
260 	}
261 	break;
262 	}
263 	FAT_DPRINT("ret: %d, offset: %d\n", ret, offset);
264 
265 	return ret;
266 }
267 
268 
269 /*
270  * Read at most 'size' bytes from the specified cluster into 'buffer'.
271  * Return 0 on success, -1 otherwise.
272  */
273 static int
274 get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
275 {
276 	int idx = 0;
277 	__u32 startsect;
278 
279 	if (clustnum > 0) {
280 		startsect = mydata->data_begin + clustnum*mydata->clust_size;
281 	} else {
282 		startsect = mydata->rootdir_sect;
283 	}
284 
285 	FAT_DPRINT("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
286 	if (disk_read(startsect, size/FS_BLOCK_SIZE , buffer) < 0) {
287 		FAT_DPRINT("Error reading data\n");
288 		return -1;
289 	}
290 	if(size % FS_BLOCK_SIZE) {
291 		__u8 tmpbuf[FS_BLOCK_SIZE];
292 		idx= size/FS_BLOCK_SIZE;
293 		if (disk_read(startsect + idx, 1, tmpbuf) < 0) {
294 			FAT_DPRINT("Error reading data\n");
295 			return -1;
296 		}
297 		buffer += idx*FS_BLOCK_SIZE;
298 
299 		memcpy(buffer, tmpbuf, size % FS_BLOCK_SIZE);
300 		return 0;
301 	}
302 
303 	return 0;
304 }
305 
306 
307 /*
308  * Read at most 'maxsize' bytes from the file associated with 'dentptr'
309  * into 'buffer'.
310  * Return the number of bytes read or -1 on fatal errors.
311  */
312 static long
313 get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
314 	     unsigned long maxsize)
315 {
316 	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
317 	unsigned int bytesperclust = mydata->clust_size * SECTOR_SIZE;
318 	__u32 curclust = START(dentptr);
319 	__u32 endclust, newclust;
320 	unsigned long actsize;
321 
322 	FAT_DPRINT("Filesize: %ld bytes\n", filesize);
323 
324 	if (maxsize > 0 && filesize > maxsize) filesize = maxsize;
325 
326 	FAT_DPRINT("Reading: %ld bytes\n", filesize);
327 
328 	actsize=bytesperclust;
329 	endclust=curclust;
330 	do {
331 		/* search for consecutive clusters */
332 		while(actsize < filesize) {
333 			newclust = get_fatent(mydata, endclust);
334 			if((newclust -1)!=endclust)
335 				goto getit;
336 			if (CHECK_CLUST(newclust, mydata->fatsize)) {
337 				FAT_DPRINT("curclust: 0x%x\n", newclust);
338 				FAT_DPRINT("Invalid FAT entry\n");
339 				return gotsize;
340 			}
341 			endclust=newclust;
342 			actsize+= bytesperclust;
343 		}
344 		/* actsize >= file size */
345 		actsize -= bytesperclust;
346 		/* get remaining clusters */
347 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
348 			FAT_ERROR("Error reading cluster\n");
349 			return -1;
350 		}
351 		/* get remaining bytes */
352 		gotsize += (int)actsize;
353 		filesize -= actsize;
354 		buffer += actsize;
355 		actsize= filesize;
356 		if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
357 			FAT_ERROR("Error reading cluster\n");
358 			return -1;
359 		}
360 		gotsize+=actsize;
361 		return gotsize;
362 getit:
363 		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
364 			FAT_ERROR("Error reading cluster\n");
365 			return -1;
366 		}
367 		gotsize += (int)actsize;
368 		filesize -= actsize;
369 		buffer += actsize;
370 		curclust = get_fatent(mydata, endclust);
371 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
372 			FAT_DPRINT("curclust: 0x%x\n", curclust);
373 			FAT_ERROR("Invalid FAT entry\n");
374 			return gotsize;
375 		}
376 		actsize=bytesperclust;
377 		endclust=curclust;
378 	} while (1);
379 }
380 
381 
382 #ifdef CONFIG_SUPPORT_VFAT
383 /*
384  * Extract the file name information from 'slotptr' into 'l_name',
385  * starting at l_name[*idx].
386  * Return 1 if terminator (zero byte) is found, 0 otherwise.
387  */
388 static int
389 slot2str(dir_slot *slotptr, char *l_name, int *idx)
390 {
391 	int j;
392 
393 	for (j = 0; j <= 8; j += 2) {
394 		l_name[*idx] = slotptr->name0_4[j];
395 		if (l_name[*idx] == 0x00) return 1;
396 		(*idx)++;
397 	}
398 	for (j = 0; j <= 10; j += 2) {
399 		l_name[*idx] = slotptr->name5_10[j];
400 		if (l_name[*idx] == 0x00) return 1;
401 		(*idx)++;
402 	}
403 	for (j = 0; j <= 2; j += 2) {
404 		l_name[*idx] = slotptr->name11_12[j];
405 		if (l_name[*idx] == 0x00) return 1;
406 		(*idx)++;
407 	}
408 
409 	return 0;
410 }
411 
412 
413 /*
414  * Extract the full long filename starting at 'retdent' (which is really
415  * a slot) into 'l_name'. If successful also copy the real directory entry
416  * into 'retdent'
417  * Return 0 on success, -1 otherwise.
418  */
419 __attribute__ ((__aligned__(__alignof__(dir_entry))))
420 __u8 get_vfatname_block[MAX_CLUSTSIZE];
421 static int
422 get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
423 	     dir_entry *retdent, char *l_name)
424 {
425 	dir_entry *realdent;
426 	dir_slot  *slotptr = (dir_slot*) retdent;
427 	__u8	  *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
428 	__u8	   counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
429 	int idx = 0;
430 
431 	while ((__u8*)slotptr < nextclust) {
432 		if (counter == 0) break;
433 		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
434 			return -1;
435 		slotptr++;
436 		counter--;
437 	}
438 
439 	if ((__u8*)slotptr >= nextclust) {
440 		dir_slot *slotptr2;
441 
442 		slotptr--;
443 		curclust = get_fatent(mydata, curclust);
444 		if (CHECK_CLUST(curclust, mydata->fatsize)) {
445 			FAT_DPRINT("curclust: 0x%x\n", curclust);
446 			FAT_ERROR("Invalid FAT entry\n");
447 			return -1;
448 		}
449 		if (get_cluster(mydata, curclust, get_vfatname_block,
450 				mydata->clust_size * SECTOR_SIZE) != 0) {
451 			FAT_DPRINT("Error: reading directory block\n");
452 			return -1;
453 		}
454 		slotptr2 = (dir_slot*) get_vfatname_block;
455 		while (slotptr2->id > 0x01) {
456 			slotptr2++;
457 		}
458 		/* Save the real directory entry */
459 		realdent = (dir_entry*)slotptr2 + 1;
460 		while ((__u8*)slotptr2 >= get_vfatname_block) {
461 			slot2str(slotptr2, l_name, &idx);
462 			slotptr2--;
463 		}
464 	} else {
465 		/* Save the real directory entry */
466 		realdent = (dir_entry*)slotptr;
467 	}
468 
469 	do {
470 		slotptr--;
471 		if (slot2str(slotptr, l_name, &idx)) break;
472 	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
473 
474 	l_name[idx] = '\0';
475 	if (*l_name == DELETED_FLAG) *l_name = '\0';
476 	else if (*l_name == aRING) *l_name = DELETED_FLAG;
477 	downcase(l_name);
478 
479 	/* Return the real directory entry */
480 	memcpy(retdent, realdent, sizeof(dir_entry));
481 
482 	return 0;
483 }
484 
485 
486 /* Calculate short name checksum */
487 static __u8
488 mkcksum(const char *str)
489 {
490 	int i;
491 	__u8 ret = 0;
492 
493 	for (i = 0; i < 11; i++) {
494 		ret = (((ret&1)<<7)|((ret&0xfe)>>1)) + str[i];
495 	}
496 
497 	return ret;
498 }
499 #endif
500 
501 
502 /*
503  * Get the directory entry associated with 'filename' from the directory
504  * starting at 'startsect'
505  */
506 __attribute__ ((__aligned__(__alignof__(dir_entry))))
507 __u8 get_dentfromdir_block[MAX_CLUSTSIZE];
508 static dir_entry *get_dentfromdir (fsdata * mydata, int startsect,
509 				   char *filename, dir_entry * retdent,
510 				   int dols)
511 {
512     __u16 prevcksum = 0xffff;
513     __u32 curclust = START (retdent);
514     int files = 0, dirs = 0;
515 
516     FAT_DPRINT ("get_dentfromdir: %s\n", filename);
517     while (1) {
518 	dir_entry *dentptr;
519 	int i;
520 
521 	if (get_cluster (mydata, curclust, get_dentfromdir_block,
522 		 mydata->clust_size * SECTOR_SIZE) != 0) {
523 	    FAT_DPRINT ("Error: reading directory block\n");
524 	    return NULL;
525 	}
526 	dentptr = (dir_entry *) get_dentfromdir_block;
527 	for (i = 0; i < DIRENTSPERCLUST; i++) {
528 	    char s_name[14], l_name[256];
529 
530 	    l_name[0] = '\0';
531 	    if (dentptr->name[0] == DELETED_FLAG) {
532 		    dentptr++;
533 		    continue;
534 	    }
535 	    if ((dentptr->attr & ATTR_VOLUME)) {
536 #ifdef CONFIG_SUPPORT_VFAT
537 		if ((dentptr->attr & ATTR_VFAT) &&
538 		    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
539 		    prevcksum = ((dir_slot *) dentptr)
540 			    ->alias_checksum;
541 		    get_vfatname (mydata, curclust, get_dentfromdir_block,
542 				  dentptr, l_name);
543 		    if (dols) {
544 			int isdir = (dentptr->attr & ATTR_DIR);
545 			char dirc;
546 			int doit = 0;
547 
548 			if (isdir) {
549 			    dirs++;
550 			    dirc = '/';
551 			    doit = 1;
552 			} else {
553 			    dirc = ' ';
554 			    if (l_name[0] != 0) {
555 				files++;
556 				doit = 1;
557 			    }
558 			}
559 			if (doit) {
560 			    if (dirc == ' ') {
561 				printf (" %8ld   %s%c\n",
562 					(long) FAT2CPU32 (dentptr->size),
563 					l_name, dirc);
564 			    } else {
565 				printf ("            %s%c\n", l_name, dirc);
566 			    }
567 			}
568 			dentptr++;
569 			continue;
570 		    }
571 		    FAT_DPRINT ("vfatname: |%s|\n", l_name);
572 		} else
573 #endif
574 		{
575 		    /* Volume label or VFAT entry */
576 		    dentptr++;
577 		    continue;
578 		}
579 	    }
580 	    if (dentptr->name[0] == 0) {
581 		if (dols) {
582 		    printf ("\n%d file(s), %d dir(s)\n\n", files, dirs);
583 		}
584 		FAT_DPRINT ("Dentname == NULL - %d\n", i);
585 		return NULL;
586 	    }
587 #ifdef CONFIG_SUPPORT_VFAT
588 	    if (dols && mkcksum (dentptr->name) == prevcksum) {
589 		dentptr++;
590 		continue;
591 	    }
592 #endif
593 	    get_name (dentptr, s_name);
594 	    if (dols) {
595 		int isdir = (dentptr->attr & ATTR_DIR);
596 		char dirc;
597 		int doit = 0;
598 
599 		if (isdir) {
600 		    dirs++;
601 		    dirc = '/';
602 		    doit = 1;
603 		} else {
604 		    dirc = ' ';
605 		    if (s_name[0] != 0) {
606 			files++;
607 			doit = 1;
608 		    }
609 		}
610 		if (doit) {
611 		    if (dirc == ' ') {
612 			printf (" %8ld   %s%c\n",
613 				(long) FAT2CPU32 (dentptr->size), s_name,
614 				dirc);
615 		    } else {
616 			printf ("            %s%c\n", s_name, dirc);
617 		    }
618 		}
619 		dentptr++;
620 		continue;
621 	    }
622 	    if (strcmp (filename, s_name) && strcmp (filename, l_name)) {
623 		FAT_DPRINT ("Mismatch: |%s|%s|\n", s_name, l_name);
624 		dentptr++;
625 		continue;
626 	    }
627 	    memcpy (retdent, dentptr, sizeof (dir_entry));
628 
629 	    FAT_DPRINT ("DentName: %s", s_name);
630 	    FAT_DPRINT (", start: 0x%x", START (dentptr));
631 	    FAT_DPRINT (", size:  0x%x %s\n",
632 			FAT2CPU32 (dentptr->size),
633 			(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
634 
635 	    return retdent;
636 	}
637 	curclust = get_fatent (mydata, curclust);
638 	if (CHECK_CLUST(curclust, mydata->fatsize)) {
639 	    FAT_DPRINT ("curclust: 0x%x\n", curclust);
640 	    FAT_ERROR ("Invalid FAT entry\n");
641 	    return NULL;
642 	}
643     }
644 
645     return NULL;
646 }
647 
648 
649 /*
650  * Read boot sector and volume info from a FAT filesystem
651  */
652 static int
653 read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
654 {
655 	__u8 block[FS_BLOCK_SIZE];
656 	volume_info *vistart;
657 
658 	if (disk_read(0, 1, block) < 0) {
659 		FAT_DPRINT("Error: reading block\n");
660 		return -1;
661 	}
662 
663 	memcpy(bs, block, sizeof(boot_sector));
664 	bs->reserved	= FAT2CPU16(bs->reserved);
665 	bs->fat_length	= FAT2CPU16(bs->fat_length);
666 	bs->secs_track	= FAT2CPU16(bs->secs_track);
667 	bs->heads	= FAT2CPU16(bs->heads);
668 #if 0 /* UNUSED */
669 	bs->hidden	= FAT2CPU32(bs->hidden);
670 #endif
671 	bs->total_sect	= FAT2CPU32(bs->total_sect);
672 
673 	/* FAT32 entries */
674 	if (bs->fat_length == 0) {
675 		/* Assume FAT32 */
676 		bs->fat32_length = FAT2CPU32(bs->fat32_length);
677 		bs->flags	 = FAT2CPU16(bs->flags);
678 		bs->root_cluster = FAT2CPU32(bs->root_cluster);
679 		bs->info_sector  = FAT2CPU16(bs->info_sector);
680 		bs->backup_boot  = FAT2CPU16(bs->backup_boot);
681 		vistart = (volume_info*) (block + sizeof(boot_sector));
682 		*fatsize = 32;
683 	} else {
684 		vistart = (volume_info*) &(bs->fat32_length);
685 		*fatsize = 0;
686 	}
687 	memcpy(volinfo, vistart, sizeof(volume_info));
688 
689 	if (*fatsize == 32) {
690 		if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0) {
691 			return 0;
692 		}
693 	} else {
694 		if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
695 			*fatsize = 12;
696 			return 0;
697 		}
698 		if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
699 			*fatsize = 16;
700 			return 0;
701 		}
702 	}
703 
704 	FAT_DPRINT("Error: broken fs_type sign\n");
705 	return -1;
706 }
707 
708 __attribute__ ((__aligned__(__alignof__(dir_entry))))
709 __u8 do_fat_read_block[MAX_CLUSTSIZE];
710 long
711 do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
712 	     int dols)
713 {
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