xref: /openbmc/u-boot/fs/fat/fat.c (revision d5cc3f52)
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 <exports.h>
31  #include <fat.h>
32  #include <asm/byteorder.h>
33  #include <part.h>
34  #include <malloc.h>
35  #include <linux/compiler.h>
36  #include <linux/ctype.h>
37  
38  #ifdef CONFIG_SUPPORT_VFAT
39  static const int vfat_enabled = 1;
40  #else
41  static const int vfat_enabled = 0;
42  #endif
43  
44  /*
45   * Convert a string to lowercase.
46   */
47  static void downcase(char *str)
48  {
49  	while (*str != '\0') {
50  		*str = tolower(*str);
51  		str++;
52  	}
53  }
54  
55  static block_dev_desc_t *cur_dev;
56  static disk_partition_t cur_part_info;
57  
58  #define DOS_BOOT_MAGIC_OFFSET	0x1fe
59  #define DOS_FS_TYPE_OFFSET	0x36
60  #define DOS_FS32_TYPE_OFFSET	0x52
61  
62  static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
63  {
64  	if (!cur_dev || !cur_dev->block_read)
65  		return -1;
66  
67  	return cur_dev->block_read(cur_dev->dev,
68  			cur_part_info.start + block, nr_blocks, buf);
69  }
70  
71  int fat_set_blk_dev(block_dev_desc_t *dev_desc, disk_partition_t *info)
72  {
73  	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
74  
75  	cur_dev = dev_desc;
76  	cur_part_info = *info;
77  
78  	/* Make sure it has a valid FAT header */
79  	if (disk_read(0, 1, buffer) != 1) {
80  		cur_dev = NULL;
81  		return -1;
82  	}
83  
84  	/* Check if it's actually a DOS volume */
85  	if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
86  		cur_dev = NULL;
87  		return -1;
88  	}
89  
90  	/* Check for FAT12/FAT16/FAT32 filesystem */
91  	if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
92  		return 0;
93  	if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
94  		return 0;
95  
96  	cur_dev = NULL;
97  	return -1;
98  }
99  
100  int fat_register_device(block_dev_desc_t *dev_desc, int part_no)
101  {
102  	disk_partition_t info;
103  
104  	/* First close any currently found FAT filesystem */
105  	cur_dev = NULL;
106  
107  	/* Read the partition table, if present */
108  	if (get_partition_info(dev_desc, part_no, &info)) {
109  		if (part_no != 0) {
110  			printf("** Partition %d not valid on device %d **\n",
111  					part_no, dev_desc->dev);
112  			return -1;
113  		}
114  
115  		info.start = 0;
116  		info.size = dev_desc->lba;
117  		info.blksz = dev_desc->blksz;
118  		info.name[0] = 0;
119  		info.type[0] = 0;
120  		info.bootable = 0;
121  #ifdef CONFIG_PARTITION_UUIDS
122  		info.uuid[0] = 0;
123  #endif
124  	}
125  
126  	return fat_set_blk_dev(dev_desc, &info);
127  }
128  
129  /*
130   * Get the first occurence of a directory delimiter ('/' or '\') in a string.
131   * Return index into string if found, -1 otherwise.
132   */
133  static int dirdelim(char *str)
134  {
135  	char *start = str;
136  
137  	while (*str != '\0') {
138  		if (ISDIRDELIM(*str))
139  			return str - start;
140  		str++;
141  	}
142  	return -1;
143  }
144  
145  /*
146   * Extract zero terminated short name from a directory entry.
147   */
148  static void get_name(dir_entry *dirent, char *s_name)
149  {
150  	char *ptr;
151  
152  	memcpy(s_name, dirent->name, 8);
153  	s_name[8] = '\0';
154  	ptr = s_name;
155  	while (*ptr && *ptr != ' ')
156  		ptr++;
157  	if (dirent->ext[0] && dirent->ext[0] != ' ') {
158  		*ptr = '.';
159  		ptr++;
160  		memcpy(ptr, dirent->ext, 3);
161  		ptr[3] = '\0';
162  		while (*ptr && *ptr != ' ')
163  			ptr++;
164  	}
165  	*ptr = '\0';
166  	if (*s_name == DELETED_FLAG)
167  		*s_name = '\0';
168  	else if (*s_name == aRING)
169  		*s_name = DELETED_FLAG;
170  	downcase(s_name);
171  }
172  
173  /*
174   * Get the entry at index 'entry' in a FAT (12/16/32) table.
175   * On failure 0x00 is returned.
176   */
177  static __u32 get_fatent(fsdata *mydata, __u32 entry)
178  {
179  	__u32 bufnum;
180  	__u32 off16, offset;
181  	__u32 ret = 0x00;
182  	__u16 val1, val2;
183  
184  	switch (mydata->fatsize) {
185  	case 32:
186  		bufnum = entry / FAT32BUFSIZE;
187  		offset = entry - bufnum * FAT32BUFSIZE;
188  		break;
189  	case 16:
190  		bufnum = entry / FAT16BUFSIZE;
191  		offset = entry - bufnum * FAT16BUFSIZE;
192  		break;
193  	case 12:
194  		bufnum = entry / FAT12BUFSIZE;
195  		offset = entry - bufnum * FAT12BUFSIZE;
196  		break;
197  
198  	default:
199  		/* Unsupported FAT size */
200  		return ret;
201  	}
202  
203  	debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
204  	       mydata->fatsize, entry, entry, offset, offset);
205  
206  	/* Read a new block of FAT entries into the cache. */
207  	if (bufnum != mydata->fatbufnum) {
208  		__u32 getsize = FATBUFBLOCKS;
209  		__u8 *bufptr = mydata->fatbuf;
210  		__u32 fatlength = mydata->fatlength;
211  		__u32 startblock = bufnum * FATBUFBLOCKS;
212  
213  		if (startblock + getsize > fatlength)
214  			getsize = fatlength - startblock;
215  
216  		startblock += mydata->fat_sect;	/* Offset from start of disk */
217  
218  		if (disk_read(startblock, getsize, bufptr) < 0) {
219  			debug("Error reading FAT blocks\n");
220  			return ret;
221  		}
222  		mydata->fatbufnum = bufnum;
223  	}
224  
225  	/* Get the actual entry from the table */
226  	switch (mydata->fatsize) {
227  	case 32:
228  		ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
229  		break;
230  	case 16:
231  		ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
232  		break;
233  	case 12:
234  		off16 = (offset * 3) / 4;
235  
236  		switch (offset & 0x3) {
237  		case 0:
238  			ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
239  			ret &= 0xfff;
240  			break;
241  		case 1:
242  			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
243  			val1 &= 0xf000;
244  			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
245  			val2 &= 0x00ff;
246  			ret = (val2 << 4) | (val1 >> 12);
247  			break;
248  		case 2:
249  			val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
250  			val1 &= 0xff00;
251  			val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
252  			val2 &= 0x000f;
253  			ret = (val2 << 8) | (val1 >> 8);
254  			break;
255  		case 3:
256  			ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
257  			ret = (ret & 0xfff0) >> 4;
258  			break;
259  		default:
260  			break;
261  		}
262  		break;
263  	}
264  	debug("FAT%d: ret: %08x, offset: %04x\n",
265  	       mydata->fatsize, ret, offset);
266  
267  	return ret;
268  }
269  
270  /*
271   * Read at most 'size' bytes from the specified cluster into 'buffer'.
272   * Return 0 on success, -1 otherwise.
273   */
274  static int
275  get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
276  {
277  	__u32 idx = 0;
278  	__u32 startsect;
279  	int ret;
280  
281  	if (clustnum > 0) {
282  		startsect = mydata->data_begin +
283  				clustnum * mydata->clust_size;
284  	} else {
285  		startsect = mydata->rootdir_sect;
286  	}
287  
288  	debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
289  
290  	if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
291  		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
292  
293  		printf("FAT: Misaligned buffer address (%p)\n", buffer);
294  
295  		while (size >= mydata->sect_size) {
296  			ret = disk_read(startsect++, 1, tmpbuf);
297  			if (ret != 1) {
298  				debug("Error reading data (got %d)\n", ret);
299  				return -1;
300  			}
301  
302  			memcpy(buffer, tmpbuf, mydata->sect_size);
303  			buffer += mydata->sect_size;
304  			size -= mydata->sect_size;
305  		}
306  	} else {
307  		idx = size / mydata->sect_size;
308  		ret = disk_read(startsect, idx, buffer);
309  		if (ret != idx) {
310  			debug("Error reading data (got %d)\n", ret);
311  			return -1;
312  		}
313  		startsect += idx;
314  		idx *= mydata->sect_size;
315  		buffer += idx;
316  		size -= idx;
317  	}
318  	if (size) {
319  		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
320  
321  		ret = disk_read(startsect, 1, tmpbuf);
322  		if (ret != 1) {
323  			debug("Error reading data (got %d)\n", ret);
324  			return -1;
325  		}
326  
327  		memcpy(buffer, tmpbuf, size);
328  	}
329  
330  	return 0;
331  }
332  
333  /*
334   * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
335   * into 'buffer'.
336   * Return the number of bytes read or -1 on fatal errors.
337   */
338  __u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
339  	__aligned(ARCH_DMA_MINALIGN);
340  
341  static long
342  get_contents(fsdata *mydata, dir_entry *dentptr, unsigned long pos,
343  	     __u8 *buffer, unsigned long maxsize)
344  {
345  	unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
346  	unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
347  	__u32 curclust = START(dentptr);
348  	__u32 endclust, newclust;
349  	unsigned long actsize;
350  
351  	debug("Filesize: %ld bytes\n", filesize);
352  
353  	if (pos >= filesize) {
354  		debug("Read position past EOF: %lu\n", pos);
355  		return gotsize;
356  	}
357  
358  	if (maxsize > 0 && filesize > pos + maxsize)
359  		filesize = pos + maxsize;
360  
361  	debug("%ld bytes\n", filesize);
362  
363  	actsize = bytesperclust;
364  
365  	/* go to cluster at pos */
366  	while (actsize <= pos) {
367  		curclust = get_fatent(mydata, curclust);
368  		if (CHECK_CLUST(curclust, mydata->fatsize)) {
369  			debug("curclust: 0x%x\n", curclust);
370  			debug("Invalid FAT entry\n");
371  			return gotsize;
372  		}
373  		actsize += bytesperclust;
374  	}
375  
376  	/* actsize > pos */
377  	actsize -= bytesperclust;
378  	filesize -= actsize;
379  	pos -= actsize;
380  
381  	/* align to beginning of next cluster if any */
382  	if (pos) {
383  		actsize = min(filesize, bytesperclust);
384  		if (get_cluster(mydata, curclust, get_contents_vfatname_block,
385  				(int)actsize) != 0) {
386  			printf("Error reading cluster\n");
387  			return -1;
388  		}
389  		filesize -= actsize;
390  		actsize -= pos;
391  		memcpy(buffer, get_contents_vfatname_block + pos, actsize);
392  		gotsize += actsize;
393  		if (!filesize)
394  			return gotsize;
395  		buffer += actsize;
396  
397  		curclust = get_fatent(mydata, curclust);
398  		if (CHECK_CLUST(curclust, mydata->fatsize)) {
399  			debug("curclust: 0x%x\n", curclust);
400  			debug("Invalid FAT entry\n");
401  			return gotsize;
402  		}
403  	}
404  
405  	actsize = bytesperclust;
406  	endclust = curclust;
407  
408  	do {
409  		/* search for consecutive clusters */
410  		while (actsize < filesize) {
411  			newclust = get_fatent(mydata, endclust);
412  			if ((newclust - 1) != endclust)
413  				goto getit;
414  			if (CHECK_CLUST(newclust, mydata->fatsize)) {
415  				debug("curclust: 0x%x\n", newclust);
416  				debug("Invalid FAT entry\n");
417  				return gotsize;
418  			}
419  			endclust = newclust;
420  			actsize += bytesperclust;
421  		}
422  
423  		/* get remaining bytes */
424  		actsize = filesize;
425  		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
426  			printf("Error reading cluster\n");
427  			return -1;
428  		}
429  		gotsize += actsize;
430  		return gotsize;
431  getit:
432  		if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
433  			printf("Error reading cluster\n");
434  			return -1;
435  		}
436  		gotsize += (int)actsize;
437  		filesize -= actsize;
438  		buffer += actsize;
439  
440  		curclust = get_fatent(mydata, endclust);
441  		if (CHECK_CLUST(curclust, mydata->fatsize)) {
442  			debug("curclust: 0x%x\n", curclust);
443  			printf("Invalid FAT entry\n");
444  			return gotsize;
445  		}
446  		actsize = bytesperclust;
447  		endclust = curclust;
448  	} while (1);
449  }
450  
451  /*
452   * Extract the file name information from 'slotptr' into 'l_name',
453   * starting at l_name[*idx].
454   * Return 1 if terminator (zero byte) is found, 0 otherwise.
455   */
456  static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
457  {
458  	int j;
459  
460  	for (j = 0; j <= 8; j += 2) {
461  		l_name[*idx] = slotptr->name0_4[j];
462  		if (l_name[*idx] == 0x00)
463  			return 1;
464  		(*idx)++;
465  	}
466  	for (j = 0; j <= 10; j += 2) {
467  		l_name[*idx] = slotptr->name5_10[j];
468  		if (l_name[*idx] == 0x00)
469  			return 1;
470  		(*idx)++;
471  	}
472  	for (j = 0; j <= 2; j += 2) {
473  		l_name[*idx] = slotptr->name11_12[j];
474  		if (l_name[*idx] == 0x00)
475  			return 1;
476  		(*idx)++;
477  	}
478  
479  	return 0;
480  }
481  
482  /*
483   * Extract the full long filename starting at 'retdent' (which is really
484   * a slot) into 'l_name'. If successful also copy the real directory entry
485   * into 'retdent'
486   * Return 0 on success, -1 otherwise.
487   */
488  static int
489  get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
490  	     dir_entry *retdent, char *l_name)
491  {
492  	dir_entry *realdent;
493  	dir_slot *slotptr = (dir_slot *)retdent;
494  	__u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
495  							PREFETCH_BLOCKS :
496  							mydata->clust_size);
497  	__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
498  	int idx = 0;
499  
500  	if (counter > VFAT_MAXSEQ) {
501  		debug("Error: VFAT name is too long\n");
502  		return -1;
503  	}
504  
505  	while ((__u8 *)slotptr < buflimit) {
506  		if (counter == 0)
507  			break;
508  		if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
509  			return -1;
510  		slotptr++;
511  		counter--;
512  	}
513  
514  	if ((__u8 *)slotptr >= buflimit) {
515  		dir_slot *slotptr2;
516  
517  		if (curclust == 0)
518  			return -1;
519  		curclust = get_fatent(mydata, curclust);
520  		if (CHECK_CLUST(curclust, mydata->fatsize)) {
521  			debug("curclust: 0x%x\n", curclust);
522  			printf("Invalid FAT entry\n");
523  			return -1;
524  		}
525  
526  		if (get_cluster(mydata, curclust, get_contents_vfatname_block,
527  				mydata->clust_size * mydata->sect_size) != 0) {
528  			debug("Error: reading directory block\n");
529  			return -1;
530  		}
531  
532  		slotptr2 = (dir_slot *)get_contents_vfatname_block;
533  		while (counter > 0) {
534  			if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
535  			    & 0xff) != counter)
536  				return -1;
537  			slotptr2++;
538  			counter--;
539  		}
540  
541  		/* Save the real directory entry */
542  		realdent = (dir_entry *)slotptr2;
543  		while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
544  			slotptr2--;
545  			slot2str(slotptr2, l_name, &idx);
546  		}
547  	} else {
548  		/* Save the real directory entry */
549  		realdent = (dir_entry *)slotptr;
550  	}
551  
552  	do {
553  		slotptr--;
554  		if (slot2str(slotptr, l_name, &idx))
555  			break;
556  	} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
557  
558  	l_name[idx] = '\0';
559  	if (*l_name == DELETED_FLAG)
560  		*l_name = '\0';
561  	else if (*l_name == aRING)
562  		*l_name = DELETED_FLAG;
563  	downcase(l_name);
564  
565  	/* Return the real directory entry */
566  	memcpy(retdent, realdent, sizeof(dir_entry));
567  
568  	return 0;
569  }
570  
571  /* Calculate short name checksum */
572  static __u8 mkcksum(const char name[8], const char ext[3])
573  {
574  	int i;
575  
576  	__u8 ret = 0;
577  
578  	for (i = 0; i < 8; i++)
579  		ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
580  	for (i = 0; i < 3; i++)
581  		ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
582  
583  	return ret;
584  }
585  
586  /*
587   * Get the directory entry associated with 'filename' from the directory
588   * starting at 'startsect'
589   */
590  __u8 get_dentfromdir_block[MAX_CLUSTSIZE]
591  	__aligned(ARCH_DMA_MINALIGN);
592  
593  static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
594  				  char *filename, dir_entry *retdent,
595  				  int dols)
596  {
597  	__u16 prevcksum = 0xffff;
598  	__u32 curclust = START(retdent);
599  	int files = 0, dirs = 0;
600  
601  	debug("get_dentfromdir: %s\n", filename);
602  
603  	while (1) {
604  		dir_entry *dentptr;
605  
606  		int i;
607  
608  		if (get_cluster(mydata, curclust, get_dentfromdir_block,
609  				mydata->clust_size * mydata->sect_size) != 0) {
610  			debug("Error: reading directory block\n");
611  			return NULL;
612  		}
613  
614  		dentptr = (dir_entry *)get_dentfromdir_block;
615  
616  		for (i = 0; i < DIRENTSPERCLUST; i++) {
617  			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
618  
619  			l_name[0] = '\0';
620  			if (dentptr->name[0] == DELETED_FLAG) {
621  				dentptr++;
622  				continue;
623  			}
624  			if ((dentptr->attr & ATTR_VOLUME)) {
625  				if (vfat_enabled &&
626  				    (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
627  				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
628  					prevcksum = ((dir_slot *)dentptr)->alias_checksum;
629  					get_vfatname(mydata, curclust,
630  						     get_dentfromdir_block,
631  						     dentptr, l_name);
632  					if (dols) {
633  						int isdir;
634  						char dirc;
635  						int doit = 0;
636  
637  						isdir = (dentptr->attr & ATTR_DIR);
638  
639  						if (isdir) {
640  							dirs++;
641  							dirc = '/';
642  							doit = 1;
643  						} else {
644  							dirc = ' ';
645  							if (l_name[0] != 0) {
646  								files++;
647  								doit = 1;
648  							}
649  						}
650  						if (doit) {
651  							if (dirc == ' ') {
652  								printf(" %8ld   %s%c\n",
653  									(long)FAT2CPU32(dentptr->size),
654  									l_name,
655  									dirc);
656  							} else {
657  								printf("            %s%c\n",
658  									l_name,
659  									dirc);
660  							}
661  						}
662  						dentptr++;
663  						continue;
664  					}
665  					debug("vfatname: |%s|\n", l_name);
666  				} else {
667  					/* Volume label or VFAT entry */
668  					dentptr++;
669  					continue;
670  				}
671  			}
672  			if (dentptr->name[0] == 0) {
673  				if (dols) {
674  					printf("\n%d file(s), %d dir(s)\n\n",
675  						files, dirs);
676  				}
677  				debug("Dentname == NULL - %d\n", i);
678  				return NULL;
679  			}
680  			if (vfat_enabled) {
681  				__u8 csum = mkcksum(dentptr->name, dentptr->ext);
682  				if (dols && csum == prevcksum) {
683  					prevcksum = 0xffff;
684  					dentptr++;
685  					continue;
686  				}
687  			}
688  
689  			get_name(dentptr, s_name);
690  			if (dols) {
691  				int isdir = (dentptr->attr & ATTR_DIR);
692  				char dirc;
693  				int doit = 0;
694  
695  				if (isdir) {
696  					dirs++;
697  					dirc = '/';
698  					doit = 1;
699  				} else {
700  					dirc = ' ';
701  					if (s_name[0] != 0) {
702  						files++;
703  						doit = 1;
704  					}
705  				}
706  
707  				if (doit) {
708  					if (dirc == ' ') {
709  						printf(" %8ld   %s%c\n",
710  							(long)FAT2CPU32(dentptr->size),
711  							s_name, dirc);
712  					} else {
713  						printf("            %s%c\n",
714  							s_name, dirc);
715  					}
716  				}
717  
718  				dentptr++;
719  				continue;
720  			}
721  
722  			if (strcmp(filename, s_name)
723  			    && strcmp(filename, l_name)) {
724  				debug("Mismatch: |%s|%s|\n", s_name, l_name);
725  				dentptr++;
726  				continue;
727  			}
728  
729  			memcpy(retdent, dentptr, sizeof(dir_entry));
730  
731  			debug("DentName: %s", s_name);
732  			debug(", start: 0x%x", START(dentptr));
733  			debug(", size:  0x%x %s\n",
734  			      FAT2CPU32(dentptr->size),
735  			      (dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
736  
737  			return retdent;
738  		}
739  
740  		curclust = get_fatent(mydata, curclust);
741  		if (CHECK_CLUST(curclust, mydata->fatsize)) {
742  			debug("curclust: 0x%x\n", curclust);
743  			printf("Invalid FAT entry\n");
744  			return NULL;
745  		}
746  	}
747  
748  	return NULL;
749  }
750  
751  /*
752   * Read boot sector and volume info from a FAT filesystem
753   */
754  static int
755  read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
756  {
757  	__u8 *block;
758  	volume_info *vistart;
759  	int ret = 0;
760  
761  	if (cur_dev == NULL) {
762  		debug("Error: no device selected\n");
763  		return -1;
764  	}
765  
766  	block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
767  	if (block == NULL) {
768  		debug("Error: allocating block\n");
769  		return -1;
770  	}
771  
772  	if (disk_read(0, 1, block) < 0) {
773  		debug("Error: reading block\n");
774  		goto fail;
775  	}
776  
777  	memcpy(bs, block, sizeof(boot_sector));
778  	bs->reserved = FAT2CPU16(bs->reserved);
779  	bs->fat_length = FAT2CPU16(bs->fat_length);
780  	bs->secs_track = FAT2CPU16(bs->secs_track);
781  	bs->heads = FAT2CPU16(bs->heads);
782  	bs->total_sect = FAT2CPU32(bs->total_sect);
783  
784  	/* FAT32 entries */
785  	if (bs->fat_length == 0) {
786  		/* Assume FAT32 */
787  		bs->fat32_length = FAT2CPU32(bs->fat32_length);
788  		bs->flags = FAT2CPU16(bs->flags);
789  		bs->root_cluster = FAT2CPU32(bs->root_cluster);
790  		bs->info_sector = FAT2CPU16(bs->info_sector);
791  		bs->backup_boot = FAT2CPU16(bs->backup_boot);
792  		vistart = (volume_info *)(block + sizeof(boot_sector));
793  		*fatsize = 32;
794  	} else {
795  		vistart = (volume_info *)&(bs->fat32_length);
796  		*fatsize = 0;
797  	}
798  	memcpy(volinfo, vistart, sizeof(volume_info));
799  
800  	if (*fatsize == 32) {
801  		if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
802  			goto exit;
803  	} else {
804  		if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
805  			*fatsize = 12;
806  			goto exit;
807  		}
808  		if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
809  			*fatsize = 16;
810  			goto exit;
811  		}
812  	}
813  
814  	debug("Error: broken fs_type sign\n");
815  fail:
816  	ret = -1;
817  exit:
818  	free(block);
819  	return ret;
820  }
821  
822  __u8 do_fat_read_at_block[MAX_CLUSTSIZE]
823  	__aligned(ARCH_DMA_MINALIGN);
824  
825  long
826  do_fat_read_at(const char *filename, unsigned long pos, void *buffer,
827  	       unsigned long maxsize, int dols)
828  {
829  	char fnamecopy[2048];
830  	boot_sector bs;
831  	volume_info volinfo;
832  	fsdata datablock;
833  	fsdata *mydata = &datablock;
834  	dir_entry *dentptr = NULL;
835  	__u16 prevcksum = 0xffff;
836  	char *subname = "";
837  	__u32 cursect;
838  	int idx, isdir = 0;
839  	int files = 0, dirs = 0;
840  	long ret = -1;
841  	int firsttime;
842  	__u32 root_cluster = 0;
843  	int rootdir_size = 0;
844  	int j;
845  
846  	if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
847  		debug("Error: reading boot sector\n");
848  		return -1;
849  	}
850  
851  	if (mydata->fatsize == 32) {
852  		root_cluster = bs.root_cluster;
853  		mydata->fatlength = bs.fat32_length;
854  	} else {
855  		mydata->fatlength = bs.fat_length;
856  	}
857  
858  	mydata->fat_sect = bs.reserved;
859  
860  	cursect = mydata->rootdir_sect
861  		= mydata->fat_sect + mydata->fatlength * bs.fats;
862  
863  	mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
864  	mydata->clust_size = bs.cluster_size;
865  	if (mydata->sect_size != cur_part_info.blksz) {
866  		printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
867  				mydata->sect_size, cur_part_info.blksz);
868  		return -1;
869  	}
870  
871  	if (mydata->fatsize == 32) {
872  		mydata->data_begin = mydata->rootdir_sect -
873  					(mydata->clust_size * 2);
874  	} else {
875  		rootdir_size = ((bs.dir_entries[1]  * (int)256 +
876  				 bs.dir_entries[0]) *
877  				 sizeof(dir_entry)) /
878  				 mydata->sect_size;
879  		mydata->data_begin = mydata->rootdir_sect +
880  					rootdir_size -
881  					(mydata->clust_size * 2);
882  	}
883  
884  	mydata->fatbufnum = -1;
885  	mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
886  	if (mydata->fatbuf == NULL) {
887  		debug("Error: allocating memory\n");
888  		return -1;
889  	}
890  
891  	if (vfat_enabled)
892  		debug("VFAT Support enabled\n");
893  
894  	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
895  	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
896  	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
897  	       "Data begins at: %d\n",
898  	       root_cluster,
899  	       mydata->rootdir_sect,
900  	       mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
901  	debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
902  	      mydata->clust_size);
903  
904  	/* "cwd" is always the root... */
905  	while (ISDIRDELIM(*filename))
906  		filename++;
907  
908  	/* Make a copy of the filename and convert it to lowercase */
909  	strcpy(fnamecopy, filename);
910  	downcase(fnamecopy);
911  
912  	if (*fnamecopy == '\0') {
913  		if (!dols)
914  			goto exit;
915  
916  		dols = LS_ROOT;
917  	} else if ((idx = dirdelim(fnamecopy)) >= 0) {
918  		isdir = 1;
919  		fnamecopy[idx] = '\0';
920  		subname = fnamecopy + idx + 1;
921  
922  		/* Handle multiple delimiters */
923  		while (ISDIRDELIM(*subname))
924  			subname++;
925  	} else if (dols) {
926  		isdir = 1;
927  	}
928  
929  	j = 0;
930  	while (1) {
931  		int i;
932  
933  		if (j == 0) {
934  			debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
935  				cursect, mydata->clust_size, DIRENTSPERBLOCK);
936  
937  			if (disk_read(cursect,
938  					(mydata->fatsize == 32) ?
939  					(mydata->clust_size) :
940  					PREFETCH_BLOCKS,
941  					do_fat_read_at_block) < 0) {
942  				debug("Error: reading rootdir block\n");
943  				goto exit;
944  			}
945  
946  			dentptr = (dir_entry *) do_fat_read_at_block;
947  		}
948  
949  		for (i = 0; i < DIRENTSPERBLOCK; i++) {
950  			char s_name[14], l_name[VFAT_MAXLEN_BYTES];
951  			__u8 csum;
952  
953  			l_name[0] = '\0';
954  			if (dentptr->name[0] == DELETED_FLAG) {
955  				dentptr++;
956  				continue;
957  			}
958  
959  			if (vfat_enabled)
960  				csum = mkcksum(dentptr->name, dentptr->ext);
961  
962  			if (dentptr->attr & ATTR_VOLUME) {
963  				if (vfat_enabled &&
964  				    (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
965  				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
966  					prevcksum =
967  						((dir_slot *)dentptr)->alias_checksum;
968  
969  					get_vfatname(mydata,
970  						     root_cluster,
971  						     do_fat_read_at_block,
972  						     dentptr, l_name);
973  
974  					if (dols == LS_ROOT) {
975  						char dirc;
976  						int doit = 0;
977  						int isdir =
978  							(dentptr->attr & ATTR_DIR);
979  
980  						if (isdir) {
981  							dirs++;
982  							dirc = '/';
983  							doit = 1;
984  						} else {
985  							dirc = ' ';
986  							if (l_name[0] != 0) {
987  								files++;
988  								doit = 1;
989  							}
990  						}
991  						if (doit) {
992  							if (dirc == ' ') {
993  								printf(" %8ld   %s%c\n",
994  									(long)FAT2CPU32(dentptr->size),
995  									l_name,
996  									dirc);
997  							} else {
998  								printf("            %s%c\n",
999  									l_name,
1000  									dirc);
1001  							}
1002  						}
1003  						dentptr++;
1004  						continue;
1005  					}
1006  					debug("Rootvfatname: |%s|\n",
1007  					       l_name);
1008  				} else {
1009  					/* Volume label or VFAT entry */
1010  					dentptr++;
1011  					continue;
1012  				}
1013  			} else if (dentptr->name[0] == 0) {
1014  				debug("RootDentname == NULL - %d\n", i);
1015  				if (dols == LS_ROOT) {
1016  					printf("\n%d file(s), %d dir(s)\n\n",
1017  						files, dirs);
1018  					ret = 0;
1019  				}
1020  				goto exit;
1021  			}
1022  			else if (vfat_enabled &&
1023  				 dols == LS_ROOT && csum == prevcksum) {
1024  				prevcksum = 0xffff;
1025  				dentptr++;
1026  				continue;
1027  			}
1028  
1029  			get_name(dentptr, s_name);
1030  
1031  			if (dols == LS_ROOT) {
1032  				int isdir = (dentptr->attr & ATTR_DIR);
1033  				char dirc;
1034  				int doit = 0;
1035  
1036  				if (isdir) {
1037  					dirc = '/';
1038  					if (s_name[0] != 0) {
1039  						dirs++;
1040  						doit = 1;
1041  					}
1042  				} else {
1043  					dirc = ' ';
1044  					if (s_name[0] != 0) {
1045  						files++;
1046  						doit = 1;
1047  					}
1048  				}
1049  				if (doit) {
1050  					if (dirc == ' ') {
1051  						printf(" %8ld   %s%c\n",
1052  							(long)FAT2CPU32(dentptr->size),
1053  							s_name, dirc);
1054  					} else {
1055  						printf("            %s%c\n",
1056  							s_name, dirc);
1057  					}
1058  				}
1059  				dentptr++;
1060  				continue;
1061  			}
1062  
1063  			if (strcmp(fnamecopy, s_name)
1064  			    && strcmp(fnamecopy, l_name)) {
1065  				debug("RootMismatch: |%s|%s|\n", s_name,
1066  				       l_name);
1067  				dentptr++;
1068  				continue;
1069  			}
1070  
1071  			if (isdir && !(dentptr->attr & ATTR_DIR))
1072  				goto exit;
1073  
1074  			debug("RootName: %s", s_name);
1075  			debug(", start: 0x%x", START(dentptr));
1076  			debug(", size:  0x%x %s\n",
1077  			       FAT2CPU32(dentptr->size),
1078  			       isdir ? "(DIR)" : "");
1079  
1080  			goto rootdir_done;	/* We got a match */
1081  		}
1082  		debug("END LOOP: j=%d   clust_size=%d\n", j,
1083  		       mydata->clust_size);
1084  
1085  		/*
1086  		 * On FAT32 we must fetch the FAT entries for the next
1087  		 * root directory clusters when a cluster has been
1088  		 * completely processed.
1089  		 */
1090  		++j;
1091  		int rootdir_end = 0;
1092  		if (mydata->fatsize == 32) {
1093  			if (j == mydata->clust_size) {
1094  				int nxtsect = 0;
1095  				int nxt_clust = 0;
1096  
1097  				nxt_clust = get_fatent(mydata, root_cluster);
1098  				rootdir_end = CHECK_CLUST(nxt_clust, 32);
1099  
1100  				nxtsect = mydata->data_begin +
1101  					(nxt_clust * mydata->clust_size);
1102  
1103  				root_cluster = nxt_clust;
1104  
1105  				cursect = nxtsect;
1106  				j = 0;
1107  			}
1108  		} else {
1109  			if (j == PREFETCH_BLOCKS)
1110  				j = 0;
1111  
1112  			rootdir_end = (++cursect - mydata->rootdir_sect >=
1113  				       rootdir_size);
1114  		}
1115  
1116  		/* If end of rootdir reached */
1117  		if (rootdir_end) {
1118  			if (dols == LS_ROOT) {
1119  				printf("\n%d file(s), %d dir(s)\n\n",
1120  				       files, dirs);
1121  				ret = 0;
1122  			}
1123  			goto exit;
1124  		}
1125  	}
1126  rootdir_done:
1127  
1128  	firsttime = 1;
1129  
1130  	while (isdir) {
1131  		int startsect = mydata->data_begin
1132  			+ START(dentptr) * mydata->clust_size;
1133  		dir_entry dent;
1134  		char *nextname = NULL;
1135  
1136  		dent = *dentptr;
1137  		dentptr = &dent;
1138  
1139  		idx = dirdelim(subname);
1140  
1141  		if (idx >= 0) {
1142  			subname[idx] = '\0';
1143  			nextname = subname + idx + 1;
1144  			/* Handle multiple delimiters */
1145  			while (ISDIRDELIM(*nextname))
1146  				nextname++;
1147  			if (dols && *nextname == '\0')
1148  				firsttime = 0;
1149  		} else {
1150  			if (dols && firsttime) {
1151  				firsttime = 0;
1152  			} else {
1153  				isdir = 0;
1154  			}
1155  		}
1156  
1157  		if (get_dentfromdir(mydata, startsect, subname, dentptr,
1158  				     isdir ? 0 : dols) == NULL) {
1159  			if (dols && !isdir)
1160  				ret = 0;
1161  			goto exit;
1162  		}
1163  
1164  		if (isdir && !(dentptr->attr & ATTR_DIR))
1165  			goto exit;
1166  
1167  		if (idx >= 0)
1168  			subname = nextname;
1169  	}
1170  
1171  	ret = get_contents(mydata, dentptr, pos, buffer, maxsize);
1172  	debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
1173  
1174  exit:
1175  	free(mydata->fatbuf);
1176  	return ret;
1177  }
1178  
1179  long
1180  do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
1181  {
1182  	return do_fat_read_at(filename, 0, buffer, maxsize, dols);
1183  }
1184  
1185  int file_fat_detectfs(void)
1186  {
1187  	boot_sector bs;
1188  	volume_info volinfo;
1189  	int fatsize;
1190  	char vol_label[12];
1191  
1192  	if (cur_dev == NULL) {
1193  		printf("No current device\n");
1194  		return 1;
1195  	}
1196  
1197  #if defined(CONFIG_CMD_IDE) || \
1198      defined(CONFIG_CMD_SATA) || \
1199      defined(CONFIG_CMD_SCSI) || \
1200      defined(CONFIG_CMD_USB) || \
1201      defined(CONFIG_MMC)
1202  	printf("Interface:  ");
1203  	switch (cur_dev->if_type) {
1204  	case IF_TYPE_IDE:
1205  		printf("IDE");
1206  		break;
1207  	case IF_TYPE_SATA:
1208  		printf("SATA");
1209  		break;
1210  	case IF_TYPE_SCSI:
1211  		printf("SCSI");
1212  		break;
1213  	case IF_TYPE_ATAPI:
1214  		printf("ATAPI");
1215  		break;
1216  	case IF_TYPE_USB:
1217  		printf("USB");
1218  		break;
1219  	case IF_TYPE_DOC:
1220  		printf("DOC");
1221  		break;
1222  	case IF_TYPE_MMC:
1223  		printf("MMC");
1224  		break;
1225  	default:
1226  		printf("Unknown");
1227  	}
1228  
1229  	printf("\n  Device %d: ", cur_dev->dev);
1230  	dev_print(cur_dev);
1231  #endif
1232  
1233  	if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
1234  		printf("\nNo valid FAT fs found\n");
1235  		return 1;
1236  	}
1237  
1238  	memcpy(vol_label, volinfo.volume_label, 11);
1239  	vol_label[11] = '\0';
1240  	volinfo.fs_type[5] = '\0';
1241  
1242  	printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
1243  
1244  	return 0;
1245  }
1246  
1247  int file_fat_ls(const char *dir)
1248  {
1249  	return do_fat_read(dir, NULL, 0, LS_YES);
1250  }
1251  
1252  long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
1253  		      unsigned long maxsize)
1254  {
1255  	printf("reading %s\n", filename);
1256  	return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO);
1257  }
1258  
1259  long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
1260  {
1261  	return file_fat_read_at(filename, 0, buffer, maxsize);
1262  }
1263  
1264  int fat_read_file(const char *filename, void *buf, int offset, int len)
1265  {
1266  	int len_read;
1267  
1268  	len_read = file_fat_read_at(filename, offset, buf, len);
1269  	if (len_read == -1) {
1270  		printf("** Unable to read file %s **\n", filename);
1271  		return -1;
1272  	}
1273  
1274  	return len_read;
1275  }
1276  
1277  void fat_close(void)
1278  {
1279  }
1280