nt9856x/rtos/BSP/u-boot/fs/exfat/exfat.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * exfat.c
 *
 * exFAT filesystem implementation
 */

#include <common.h>
#include <blk.h> //new
#include <config.h>
#include <exports.h>
#include <exfat.h>
#include <fs.h>
#include <asm/byteorder.h>
#include <part.h>
#include <malloc.h>
#include <memalign.h> //new
#include <linux/compiler.h>
#include <linux/ctype.h>

/*
 * Convert a string to lowercase.  Converts at most 'len' characters,
 * 'len' may be larger than the length of 'str' if 'str' is NULL
 * terminated.
 */
static void downcase(char *str, size_t len)
{
	while (*str != '\0' && len--) {
		*str = tolower(*str);
		str++;
	}
}

static struct blk_desc *cur_dev;
static disk_partition_t cur_part_info;

#define DOS_BOOT_MAGIC_OFFSET	0x1fe
#define DOS_FS_TYPE_OFFSET	0x36
#define DOS_FS32_TYPE_OFFSET	0x52
#define DOS_EXFAT_TYPE_OFFSET	0x3

static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
{
	ulong ret;

	if (!cur_dev)
		return -1;

	ret = blk_dread(cur_dev, cur_part_info.start + block, nr_blocks, buf);

	if (ret != nr_blocks)
		return -1;

	return ret;
}

int exfat_set_blk_dev(struct blk_desc *dev_desc, disk_partition_t *info)
{
	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);

	cur_dev = dev_desc;
	cur_part_info = *info;

	/* Make sure it has a valid FAT header */
	if (disk_read(0, 1, buffer) != 1) {
		cur_dev = NULL;
		return -1;
	}

	/* Check if it's actually a DOS volume */
	if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
		cur_dev = NULL;
		return -1;
	}

	/* Check for exFAT filesystem */
	if (!memcmp(buffer + DOS_EXFAT_TYPE_OFFSET, EXFAT_SIGN, 8))
		return 0;

	cur_dev = NULL;
	return -1;
}

int exfat_register_device(struct blk_desc *dev_desc, int part_no)
{
	disk_partition_t info;

	/* First close any currently found FAT filesystem */
	cur_dev = NULL;

	/* Read the partition table, if present */
	if (part_get_info(dev_desc, part_no, &info)) {
		if (part_no != 0) {
			printf("** Partition %d not valid on device %d **\n",
					part_no, dev_desc->devnum);
			return -1;
		}

		info.start = 0;
		info.size = dev_desc->lba;
		info.blksz = dev_desc->blksz;
		info.name[0] = 0;
		info.type[0] = 0;
		info.bootable = 0;
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
		info.uuid[0] = 0;
#endif
	}

	return exfat_set_blk_dev(dev_desc, &info);
}

/*
 * Get the first occurence of a directory delimiter ('/' or '\') in a string.
 * Return index into string if found, -1 otherwise.
 */
static int dirdelim(char *str)
{
	char *start = str;

	while (*str != '\0') {
		if (ISDIRDELIM(*str))
			return str - start;
		str++;
	}
	return -1;
}

static int flush_dirty_exfat_buffer(exfat_fsdata *mydata);

#if !CONFIG_IS_ENABLED(EXFAT_WRITE)
/* Stub for read only operation */
int flush_dirty_exfat_buffer(exfat_fsdata *mydata)
{
	(void)(mydata);
	return 0;
}
#endif

/*
 * Get the entry at index 'entry' in a exFAT table.
 * On failure 0x00 is returned.
 */
static __u32 exfat_get_fatent(exfat_fsdata *mydata, __u32 entry, exfat_stream_dentry *strmptr)
{
	__u32 bufnum;
	__u32 offset;
	__u32 ret = 0x00;

	// new
	if (CHECK_CLUST(entry, mydata->fatsize)) {
		printf("Error: Invalid FAT entry: 0x%08x\n", entry);
		return ret;
	}

	switch (mydata->fatsize) {
	case 32:
		bufnum = entry / EXFATBUFSIZE;
		offset = entry - bufnum * EXFATBUFSIZE;
		break;
	default:
		/* Unsupported FAT size */
		return ret;
	}

	debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
	       mydata->fatsize, entry, entry, offset, offset);

	if (strmptr && EXFAT_IS_CONTIGUOUS(strmptr)) {
		__u32 first_clus;
		__u32 clus_count;
		unsigned long filesize = (unsigned long)EXFAT_SIZE(strmptr); //can not use __u64 division, or compile will failed
																 //(limitation: file size should not exceed 4GB)

		first_clus = EXFAT_SIZE(strmptr);
		clus_count = (filesize + mydata->sect_size * mydata->clust_size - 1) / (mydata->sect_size * mydata->clust_size);

		if (entry < (first_clus +  clus_count - 1)) {
			// startClus can get next cluster , but should in Cluscount
			ret = entry + 1 ;
		} else {
			//DBG_IND(" Cluster out of range is FirstClus = 0X%X ,StartClus = 0x%X , ClusCount = 0x%X \r\n" ,FirstClus ,StartClus, ClusCount);
			ret = 0xFFFFFFFF;
		}
		return ret;
	}

	/* Read a new block of FAT entries into the cache. */
	if (bufnum != mydata->fatbufnum) {
		__u32 getsize = FATBUFBLOCKS;
		__u8 *bufptr = mydata->fatbuf;
		__u32 fatlength = mydata->fatlength;
		__u32 startblock = bufnum * FATBUFBLOCKS;

		if (startblock + getsize > fatlength)
			getsize = fatlength - startblock;

		startblock += mydata->fat_sect;	/* Offset from start of disk */

		/* Write back the fatbuf to the disk */
		if (flush_dirty_exfat_buffer(mydata) < 0)
			return -1;

		if (disk_read(startblock, getsize, bufptr) < 0) {
			debug("Error reading FAT blocks\n");
			return ret;
		}
		mydata->fatbufnum = bufnum;
	}

	/* Get the actual entry from the table */
	switch (mydata->fatsize) {
	case 32:
		ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
		break;
	}
	debug("FAT%d: ret: %08x, entry: 0x%08x, offset: %04x\n",
	       mydata->fatsize, ret, entry, offset);

	return ret;
}

/*
 * Read at most 'size' bytes from the specified cluster into 'buffer'.
 * Return 0 on success, -1 otherwise.
 */
static int
exfat_get_cluster(exfat_fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
{
	__u32 idx = 0;
	__u32 startsect;
	int ret;

	if (clustnum > 0) {
		/* startsect = mydata->data_begin +
				clustnum * mydata->clust_size; */
		startsect = exfat_clust_to_sect(mydata, clustnum);
	} else {
		startsect = mydata->rootdir_sect;
	}

	debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);

	if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);

		debug("FAT: Misaligned buffer address (%p)\n", buffer);

		while (size >= mydata->sect_size) {
			ret = disk_read(startsect++, 1, tmpbuf);
			if (ret != 1) {
				debug("Error reading data (got %d)\n", ret);
				return -1;
			}

			memcpy(buffer, tmpbuf, mydata->sect_size);
			buffer += mydata->sect_size;
			size -= mydata->sect_size;
		}
	} else {
		idx = size / mydata->sect_size;
		ret = disk_read(startsect, idx, buffer);
		if (ret != idx) {
			debug("Error reading data (got %d)\n", ret);
			return -1;
		}
		startsect += idx;
		idx *= mydata->sect_size;
		buffer += idx;
		size -= idx;
	}
	if (size) {
		ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);

		ret = disk_read(startsect, 1, tmpbuf);
		if (ret != 1) {
			debug("Error reading data (got %d)\n", ret);
			return -1;
		}

		memcpy(buffer, tmpbuf, size);
	}

	return 0;
}

/*
 * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
 * into 'buffer'.
 * Update the number of bytes read in *gotsize or return -1 on fatal errors.
 */
 /*
__u8 get_contents_vexfatname_block[EXFAT_MAX_CLUSTSIZE]
	__aligned(ARCH_DMA_MINALIGN);
 */

static long
exfat_get_contents(exfat_fsdata *mydata, exfat_stream_dentry *strmptr, loff_t pos,
	     __u8 *buffer, loff_t maxsize)
{
	loff_t filesize = EXFAT_SIZE(strmptr), gotsize = 0;
	unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
	__u32 curclust = EXFAT_START(strmptr);
	__u32 endclust, newclust;
	loff_t actsize;

	debug("Filesize: %llu bytes\n", filesize);

	if (EXFAT_SIZE(strmptr) >= 0xFFFFFFFFULL) {
		debug("size too large\r\n");
		return -1;
	}

	if (pos >= filesize) {
		debug("Read position past EOF: %llu\n", pos);
		return gotsize;
	}

	if (maxsize > 0 && filesize > pos + maxsize)
		filesize = pos + maxsize;

	debug("%llu bytes\n", filesize);

	actsize = bytesperclust;

	/* go to cluster at pos */
	while (actsize <= pos) {
		curclust = exfat_get_fatent(mydata, curclust, strmptr);
		if (CHECK_CLUST(curclust, mydata->fatsize)) {
			debug("curclust: 0x%x\n", curclust);
			debug("Invalid FAT entry\n");
			return gotsize;
		}
		actsize += bytesperclust;
	}

	/* actsize > pos */
	actsize -= bytesperclust;
	filesize -= actsize;
	pos -= actsize;

	/* align to beginning of next cluster if any */
	if (pos) {
		__u8 *tmp_buffer;

		actsize = min(filesize, (loff_t)bytesperclust);
		tmp_buffer = malloc_cache_aligned(actsize);
		if (!tmp_buffer) {
			debug("Error: allocating buffer\n");
			return -ENOMEM;
		}

		if (exfat_get_cluster(mydata, curclust, tmp_buffer, actsize) != 0) {
			printf("Error reading cluster\n");
			free(tmp_buffer);
			return -1;
		}
		filesize -= actsize;
		actsize -= pos;
		memcpy(buffer, tmp_buffer + pos, actsize);
		free(tmp_buffer);
		gotsize += actsize;
		if (!filesize)
			return gotsize;
		buffer += actsize;

		curclust = exfat_get_fatent(mydata, curclust, strmptr);
		if (CHECK_CLUST(curclust, mydata->fatsize)) {
			debug("curclust: 0x%x\n", curclust);
			debug("Invalid FAT entry\n");
			return gotsize;
		}
	}

	actsize = bytesperclust;
	endclust = curclust;

	do {
		/* search for consecutive clusters */
		while (actsize < filesize) {
			newclust = exfat_get_fatent(mydata, endclust, strmptr);
			if ((newclust - 1) != endclust)
				goto getit;
			if (CHECK_CLUST(newclust, mydata->fatsize)) {
				debug("curclust: 0x%x\n", newclust);
				debug("Invalid FAT entry\n");
				return gotsize;
			}
			endclust = newclust;
			actsize += bytesperclust;
		}

		/* get remaining bytes */
		actsize = filesize;
		if (exfat_get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
			printf("Error reading cluster\n");
			return -1;
		}
		gotsize += actsize;
		return gotsize;
getit:
		if (exfat_get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
			printf("Error reading cluster\n");
			return -1;
		}
		gotsize += (int)actsize;
		filesize -= actsize;
		buffer += actsize;

		curclust = exfat_get_fatent(mydata, endclust, strmptr);
		if (CHECK_CLUST(curclust, mydata->fatsize)) {
			debug("curclust: 0x%x\n", curclust);
			printf("Invalid FAT entry\n");
			return gotsize;
		}
		actsize = bytesperclust;
		endclust = curclust;
	} while (1);
}

/*
 * Extract the file name information from 'slotptr' into 'l_name',
 * starting at l_name[*idx].
 * Return 1 if terminator (zero byte) is found, 0 otherwise.
 */
static int exfat_slot2str(exfat_name_dentry *slotptr, char *l_name, int *idx)
{
	int i;

	for (i = 0; i < EXFAT_NAME_ENTRY_MAXCHAR; i++) {
		if (slotptr->name[i] > 0x80)
			printf("NON-ASCII code 0x%X\r\n", slotptr->name[i]);

		if (slotptr->entry_type != EXFAT_ENTRY_TYPE_NAME)
			return 0;

		l_name[*idx] = (char)slotptr->name[i];
		if (l_name[*idx] == 0x00)
			return 1;
		(*idx)++;
	}

	return 0;
}

//Note: Only supports ASCII filename
static int
get_exfatname(exfat_fsdata *mydata, int curclust, __u8 *buf_head,
	     exfat_entry_set *curdent, char *l_name, exfat_stream_dentry *ret_strmptr)
{
	exfat_name_dentry *name_deptr = &curdent->name_dentry[0];
	exfat_stream_dentry *strm_deptr = &curdent->stream_dentry;
	__u8 *buflimit = buf_head + mydata->sect_size * ((curclust == 0) ?
							EXFAT_PREFETCH_BLOCKS :
							mydata->clust_size);
	//__u8 counter = (curdent->stream_dentry.name_len + EXFAT_NAME_ENTRY_MAXCHAR - 1) / EXFAT_NAME_ENTRY_MAXCHAR;
	__u8 counter = (curdent->file_dentry.second_count - 1); //second_count excludes the stream entry
	int idx = 0;

	if (counter > EXFAT_NAME_ENTRY_MAXNUM) {
		debug("Error: EXFAT name is too long\n");
		return -1;
	}

	while (counter) {
		if ((__u8 *)name_deptr >= buflimit) {
			exfat_name_dentry *name_deptr2;
			__u8 *tmp_buffer;

			if (curclust == 0)
				return -1;
			curclust = exfat_get_fatent(mydata, curclust, NULL);
			if (CHECK_CLUST(curclust, mydata->fatsize)) {
				debug("curclust: 0x%x\n", curclust);
				printf("Invalid FAT entry\n");
				return -1;
			}

			tmp_buffer = malloc_cache_aligned(mydata->clust_size * mydata->sect_size);
			if (!tmp_buffer) {
				debug("Error: allocating buffer\n");
				return -ENOMEM;
			}

			if (exfat_get_cluster(mydata, curclust, tmp_buffer,
					mydata->clust_size * mydata->sect_size) != 0) {
				debug("Error: reading directory block\n");
				return -1;
			}

			name_deptr2 = (exfat_name_dentry *)(tmp_buffer + ((__u8 *)name_deptr - buflimit));

			while (counter) {
				exfat_slot2str(name_deptr2, l_name, &idx);
				name_deptr2++;
				counter--;
			}
			free(tmp_buffer);
		} else {
			exfat_slot2str(name_deptr, l_name, &idx);
			name_deptr++;
			counter--;
		}
	}
	l_name[idx] = '\0';
	downcase(l_name, EXFAT_MAXLEN_BYTES);

	if ((__u8 *)strm_deptr < buflimit) {
		memcpy(ret_strmptr, strm_deptr, sizeof(exfat_stream_dentry));
	} else {
		__u8 *tmp_buffer;
		tmp_buffer = malloc_cache_aligned(sizeof(exfat_stream_dentry));
		if (!tmp_buffer) {
			debug("Error: allocating buffer\n");
			return -ENOMEM;
		}

		memcpy(ret_strmptr, tmp_buffer, sizeof(exfat_stream_dentry));

		free(tmp_buffer);
	}

	return 0;
}

/*
 * Read boot sector and volume info from a FAT filesystem
 */
static int
exfat_read_bootsectandvi(exfat_boot_sector *bs, exfat_volume_info *volinfo, int *fatsize)
{
	__u8 *block;
	int ret = 0;

	if (cur_dev == NULL) {
		debug("Error: no device selected\n");
		return -1;
	}

	/* block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz); */
	block = malloc_cache_aligned(cur_dev->blksz); //new
	if (block == NULL) {
		debug("Error: allocating block\n");
		return -1;
	}

	if (disk_read(0, 1, block) < 0) {
		debug("Error: reading block\n");
		goto fail;
	}

	//dump_buf(block, 512);

	memcpy(bs, block, sizeof(exfat_boot_sector));
	bs->partition_offset[0] = FAT2CPU32(bs->partition_offset[0]);
	bs->partition_offset[1] = FAT2CPU32(bs->partition_offset[1]);
	bs->volume_length[0] = FAT2CPU32(bs->volume_length[0]);
	bs->volume_length[1] = FAT2CPU32(bs->volume_length[1]);
	bs->fat_offset = FAT2CPU32(bs->fat_offset);
	bs->fat_length = FAT2CPU32(bs->fat_length);
	bs->cluster_heap_offset = FAT2CPU32(bs->cluster_heap_offset);
	bs->cluster_count = FAT2CPU32(bs->cluster_count);
	bs->first_clus_of_root_dir = FAT2CPU32(bs->first_clus_of_root_dir);
	bs->volume_serial_number = FAT2CPU32(bs->volume_serial_number);
	bs->file_system_revision = FAT2CPU16(bs->file_system_revision);
	bs->volume_flags = FAT2CPU16(bs->volume_flags);

	*fatsize = 32;

	memcpy(volinfo->fs_type, bs->file_system_name, sizeof(bs->file_system_name));

	if (strncmp(EXFAT_SIGN, bs->file_system_name, EXFAT_SIGNLEN) == 0)
		goto exit;

	debug("Error: broken fs_type sign\n");
fail:
	ret = -1;
exit:
	free(block);
	return ret;
}

__u8 do_exfat_read_at_block[EXFAT_MAX_CLUSTSIZE]
	__aligned(ARCH_DMA_MINALIGN);

long
do_exfat_read_at(const char *filename, loff_t pos, void *buffer,
	       loff_t maxsize, int dols, int dogetsize)
{
	char fnamecopy[2048];
	exfat_boot_sector bs;
	exfat_volume_info volinfo;
	exfat_fsdata datablock;
	exfat_fsdata *mydata = &datablock;
	//exfat_dir_entry *dentptr = NULL;
	exfat_entry_set *exdentptr = NULL;
	exfat_stream_dentry strmdent;
	//char *subname = "";
	__u32 cursect;
	int idx, isdir = 0;
	int files = 0, dirs = 0;
	long ret = -1;
	//int firsttime;
	__u32 root_cluster = 0;
	int j;
	int sect_per_clus;

	if (exfat_read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
		debug("Error: reading boot sector\n");
		return -1;
	}

	sect_per_clus = 1 << bs.sector_per_clus_shift;
	root_cluster = bs.first_clus_of_root_dir;

	mydata->fatlength = bs.fat_length;
	mydata->fat_sect = bs.fat_offset;

	mydata->fats = bs.number_of_fats;

	cursect = mydata->rootdir_sect
		= bs.cluster_heap_offset + (bs.first_clus_of_root_dir - 2) * sect_per_clus;

	mydata->sect_size = 1 << bs.byte_per_sector_shift;
	mydata->clust_size = sect_per_clus;
	if (mydata->sect_size != cur_part_info.blksz) {
		printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
				mydata->sect_size, cur_part_info.blksz);
		return -1;
	}

	if (mydata->clust_size * mydata->sect_size > EXFAT_MAX_CLUSTSIZE) {
		printf("Error: clust_size(%d) > MAX(%d) bytes\n",
				mydata->clust_size * mydata->sect_size,	EXFAT_MAX_CLUSTSIZE);
		return -1;
	}

	mydata->data_begin = mydata->rootdir_sect -	(mydata->clust_size * root_cluster); //relative to root cluster

	mydata->fatbufnum = -1;
	mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
	if (mydata->fatbuf == NULL) {
		debug("Error: allocating memory\n");
		return -1;
	}

	//if (vfat_enabled)
	//	debug("VFAT Support enabled\n");

	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
	       "Data begins at: %d\n",
	       root_cluster,
	       mydata->rootdir_sect,
	       mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
	debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
	      mydata->clust_size);

	/* "cwd" is always the root... */
	while (ISDIRDELIM(*filename))
		filename++;

	/* Make a copy of the filename and convert it to lowercase */
	strcpy(fnamecopy, filename);
	downcase(fnamecopy, 2048);

	if (*fnamecopy == '\0') {
		if (!dols)
			goto exit;

		dols = LS_ROOT;
	} else if ((idx = dirdelim(fnamecopy)) >= 0) {
		#if 1
		printf("Error: Only supports root files\r\n");
		goto exit;
		#else
		isdir = 1;
		fnamecopy[idx] = '\0';
		subname = fnamecopy + idx + 1;

		/* Handle multiple delimiters */
		while (ISDIRDELIM(*subname))
			subname++;
		#endif
	} else if (dols) {
		isdir = 1;
	}

	j = 0;
	while (1) {
		int i;

		if (j == 0) {
			debug("FAT read sect=%d, clust_size=%d, EXDIRENTSPERBLOCK=%zd\n",
				cursect, mydata->clust_size, EXFAT_DIRENTSPERBLOCK);

			if (disk_read(cursect,
					mydata->clust_size,
					do_exfat_read_at_block) < 0) {
				debug("Error: reading rootdir block\n");
				goto exit;
			}

			//dentptr = (exfat_dir_entry *) do_exfat_read_at_block;
			exdentptr = (exfat_entry_set *) do_exfat_read_at_block;
		}

		for (i = 0; i < EXFAT_DIRENTSPERCLUST; i++) {
			char l_name[EXFAT_MAXLEN_BYTES];

			l_name[0] = '\0';
			/*
			if (dentptr->name[0] == DELETED_FLAG) {
				dentptr++;
				continue;
			}
			*/
			if (exdentptr->file_dentry.entry_type == 0) { //search end
				debug("RootDentname == NULL - %d\n", i);
				if (dols == LS_ROOT) {
					printf("\n%d file(s), %d dir(s)\n\n",
						files, dirs);
					ret = 0;
				}
				goto exit;
			}

			if (exdentptr->file_dentry.entry_type != EXFAT_ENTRY_TYPE_FILE) {
				exdentptr = (exfat_entry_set *)((char *)exdentptr + EXFAT_SIZE_PER_ENTRY);
				continue;
			}

			//dump_buf(exdentptr, 512);
			get_exfatname(mydata,
						root_cluster,
						do_exfat_read_at_block,
						exdentptr, l_name, &strmdent);
			debug("Rootexfatname: |%s|\n", l_name);

			if (dols == LS_ROOT) {
				char dirc;
				int doit = 0;
				int isdir =
					(exdentptr->file_dentry.attrib & ATTR_DIR);

				if (isdir) {
					dirs++;
					dirc = '/';
					doit = 1;
				} else {
					dirc = ' ';
					if (l_name[0] != 0) {
						files++;
						doit = 1;
					}
				}
				if (doit) {
					if (dirc == ' ') {
						printf(" %8lld   %s%c\n",
							EXFAT_SIZE(&strmdent),
							l_name,
							dirc);
					} else {
						printf("            %s%c\n",
							l_name,
							dirc);
					}
				}
				exdentptr = (exfat_entry_set *)((char *)exdentptr + EXFAT_SIZE_PER_ENTRY);
				continue;
			} else { //not dols, should read a file
				if (strcmp(fnamecopy, l_name)) {
					debug("RootMismatch: %s|%s|\n", fnamecopy, l_name);
					exdentptr = (exfat_entry_set *)((char *)exdentptr + EXFAT_SIZE_PER_ENTRY);
					continue;
				}

				if (isdir && !(exdentptr->file_dentry.attrib & ATTR_DIR))
					goto exit;

				debug("RootName: %s", l_name);
				debug(", start: 0x%x", EXFAT_START(&strmdent));
				debug(", size:  0x%llx %s\n",
				       EXFAT_SIZE(&strmdent),
				       isdir ? "(DIR)" : "");

				goto rootdir_done;	/* We got a match */
			}
		}
		debug("END LOOP: j=%d   clust_size=%d\n", j,
		       mydata->clust_size);

		/*
		 * we must fetch the entries for the next
		 * root directory clusters when a cluster has been
		 * completely processed.
		 */
		j += mydata->clust_size;
		int rootdir_end = 0;

		if (j == mydata->clust_size) {
			int nxtsect = 0;
			int nxt_clust = 0;

			nxt_clust = exfat_get_fatent(mydata, root_cluster, NULL);
			rootdir_end = EXFAT_CHECK_CLUST(nxt_clust, 32);

			nxtsect = mydata->data_begin +
				(nxt_clust * mydata->clust_size);

			root_cluster = nxt_clust;

			cursect = nxtsect;
			j = 0;
		}

		/* If end of rootdir reached */
		if (rootdir_end) {
			if (dols == LS_ROOT) {
				printf("\n%d file(s), %d dir(s)\n\n",
				       files, dirs);
				ret = 0;
			}
			goto exit;
		}
	}
rootdir_done:

#if 1
	if(dogetsize)
		ret = EXFAT_SIZE(&strmdent);
	else
		ret = exfat_get_contents(mydata, &strmdent, pos, buffer, maxsize);

	debug("Size: %lld, got: %ld\n", EXFAT_SIZE(&strmdent), ret);
	//dump_buf(buffer, 512);
#else
	firsttime = 1;

	while (isdir) {
		int startsect = mydata->data_begin
			+ EXFAT_START(exdentptr) * mydata->clust_size;
		exfat_dir_entry dent;
		char *nextname = NULL;

		dent = *dentptr;
		dentptr = &dent;

		idx = dirdelim(subname);

		if (idx >= 0) {
			subname[idx] = '\0';
			nextname = subname + idx + 1;
			/* Handle multiple delimiters */
			while (ISDIRDELIM(*nextname))
				nextname++;
			if (dols && *nextname == '\0')
				firsttime = 0;
		} else {
			if (dols && firsttime) {
				firsttime = 0;
			} else {
				isdir = 0;
			}
		}

		if (get_dentfromdir(mydata, startsect, subname, dentptr,
				     isdir ? 0 : dols) == NULL) {
			if (dols && !isdir)
				ret = 0;
			goto exit;
		}

		if (isdir && !(dentptr->attr & ATTR_DIR))
			goto exit;

		if (idx >= 0)
			subname = nextname;
	}

	if (dogetsize)
		ret = FAT2CPU32(dentptr->size);
	else
		ret = get_contents(mydata, dentptr, pos, buffer, maxsize);
	debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
#endif

exit:
	free(mydata->fatbuf);

	return ret;
}

long
do_exfat_read(const char *filename, void *buffer, loff_t maxsize, int dols)
{
	return do_exfat_read_at(filename, 0, buffer, maxsize, dols, 0);
}

int file_exfat_detectfs(void)
{
	exfat_boot_sector bs;
	exfat_volume_info volinfo;
	int fatsize;
	char vol_label[12];

	if (cur_dev == NULL) {
		printf("No current device\n");
		return 1;
	}

#if defined(CONFIG_IDE) || \
    defined(CONFIG_SATA) || \
    defined(CONFIG_SCSI) || \
    defined(CONFIG_CMD_USB) || \
    defined(CONFIG_MMC)
	printf("Interface:  ");
	switch (cur_dev->if_type) {
	case IF_TYPE_IDE:
		printf("IDE");
		break;
	case IF_TYPE_SATA:
		printf("SATA");
		break;
	case IF_TYPE_SCSI:
		printf("SCSI");
		break;
	case IF_TYPE_ATAPI:
		printf("ATAPI");
		break;
	case IF_TYPE_USB:
		printf("USB");
		break;
	case IF_TYPE_DOC:
		printf("DOC");
		break;
	case IF_TYPE_MMC:
		printf("MMC");
		break;
	default:
		printf("Unknown");
	}

	printf("\n  Device %d: ", cur_dev->devnum);
	dev_print(cur_dev);
#endif

	if (exfat_read_bootsectandvi(&bs, &volinfo, &fatsize)) {
		printf("\nNo valid FAT fs found\n");
		return 1;
	}

	memcpy(vol_label, volinfo.volume_label, 11);
	vol_label[11] = '\0';
	volinfo.fs_type[5] = '\0';

	printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);

	return 0;
}

int exfat_ls(const char *dir)
{
	return do_exfat_read(dir, NULL, 0, LS_YES);
}

int exfat_exists(const char *filename)
{
	long ret;
	ret = do_exfat_read_at(filename, 0, NULL, 0, LS_NO, 1);
	return ret >= 0;
}

int exfat_size(const char *filename, loff_t *size)
{
	long ret;

	*size = 0;
	ret = do_exfat_read_at(filename, 0, NULL, 0, LS_NO, 1);

	if (ret == -1) {
		return -1;
	}

	*size = (loff_t)ret;
	return 0;
}

int file_exfat_read_at(const char *filename, loff_t pos, void *buffer,
		     loff_t maxsize, loff_t *actread)
{
	long ret = -1;

	*actread = 0;
	ret = do_exfat_read_at(filename, pos, buffer, maxsize, LS_NO, 0);

	if (ret == -1) {
		return -1;
	}

	*actread = (loff_t)ret;
	return 0;
}

int file_exfat_read(const char *filename, void *buffer, int maxsize)
{
	loff_t actread;
	int ret;

	ret =  file_exfat_read_at(filename, 0, buffer, maxsize, &actread);
	if (ret)
		return ret;
	else
		return actread;
}

int exfat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
		  loff_t *actread)
{
	int ret;

	ret = file_exfat_read_at(filename, offset, buf, len, actread);
	if (ret)
		printf("** Unable to read file %s **\n", filename);

	return ret;
}

int exfat_opendir(const char *filename, struct fs_dir_stream **dirsp)
{
	return 0;
}

int exfat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp)
{
	return 0;
}

void exfat_closedir(struct fs_dir_stream *dirs)
{
}

void exfat_close(void)
{
}