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u-boot/fs/fat/fat.c

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/*
* fat.c
*
* R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
*
* 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
* 2003-03-10 - kharris@nexus-tech.net - ported to uboot
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <blk.h>
#include <config.h>
#include <exports.h>
#include <fat.h>
#include <asm/byteorder.h>
#include <part.h>
#include <malloc.h>
#include <memalign.h>
#include <linux/compiler.h>
#include <linux/ctype.h>
#ifdef CONFIG_SUPPORT_VFAT
static const int vfat_enabled = 1;
#else
static const int vfat_enabled = 0;
#endif
/*
* Convert a string to lowercase.
*/
static void downcase(char *str)
{
while (*str != '\0') {
*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
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 (nr_blocks && ret == 0)
return -1;
return ret;
}
int fat_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 FAT12/FAT16/FAT32 filesystem */
if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
return 0;
if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
return 0;
cur_dev = NULL;
return -1;
}
int fat_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 fat_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;
}
/*
* Extract zero terminated short name from a directory entry.
*/
static void get_name(dir_entry *dirent, char *s_name)
{
char *ptr;
memcpy(s_name, dirent->name, 8);
s_name[8] = '\0';
ptr = s_name;
while (*ptr && *ptr != ' ')
ptr++;
if (dirent->ext[0] && dirent->ext[0] != ' ') {
*ptr = '.';
ptr++;
memcpy(ptr, dirent->ext, 3);
ptr[3] = '\0';
while (*ptr && *ptr != ' ')
ptr++;
}
*ptr = '\0';
if (*s_name == DELETED_FLAG)
*s_name = '\0';
else if (*s_name == aRING)
*s_name = DELETED_FLAG;
downcase(s_name);
}
static int flush_dirty_fat_buffer(fsdata *mydata);
#if !defined(CONFIG_FAT_WRITE)
/* Stub for read only operation */
int flush_dirty_fat_buffer(fsdata *mydata)
{
(void)(mydata);
return 0;
}
#endif
/*
* Get the entry at index 'entry' in a FAT (12/16/32) table.
* On failure 0x00 is returned.
*/
static __u32 get_fatent(fsdata *mydata, __u32 entry)
{
__u32 bufnum;
__u32 offset, off8;
__u32 ret = 0x00;
if (CHECK_CLUST(entry, mydata->fatsize)) {
printf("Error: Invalid FAT entry: 0x%08x\n", entry);
return ret;
}
switch (mydata->fatsize) {
case 32:
bufnum = entry / FAT32BUFSIZE;
offset = entry - bufnum * FAT32BUFSIZE;
break;
case 16:
bufnum = entry / FAT16BUFSIZE;
offset = entry - bufnum * FAT16BUFSIZE;
break;
case 12:
bufnum = entry / FAT12BUFSIZE;
offset = entry - bufnum * FAT12BUFSIZE;
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);
/* 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;
/* Cap length if fatlength is not a multiple of 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_fat_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;
case 16:
ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
break;
case 12:
off8 = (offset * 3) / 2;
/* fatbut + off8 may be unaligned, read in byte granularity */
ret = mydata->fatbuf[off8] + (mydata->fatbuf[off8 + 1] << 8);
if (offset & 0x1)
ret >>= 4;
ret &= 0xfff;
}
debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%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
get_cluster(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;
} 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);
printf("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_vfatname_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
__u8 *buffer, loff_t maxsize, loff_t *gotsize)
{
loff_t filesize = FAT2CPU32(dentptr->size);
unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
__u32 curclust = START(dentptr);
__u32 endclust, newclust;
loff_t actsize;
*gotsize = 0;
debug("Filesize: %llu bytes\n", filesize);
if (pos >= filesize) {
debug("Read position past EOF: %llu\n", pos);
return 0;
}
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 = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
debug("Invalid FAT entry\n");
return 0;
}
actsize += bytesperclust;
}
/* actsize > pos */
actsize -= bytesperclust;
filesize -= actsize;
pos -= actsize;
/* align to beginning of next cluster if any */
if (pos) {
actsize = min(filesize, (loff_t)bytesperclust);
if (get_cluster(mydata, curclust, get_contents_vfatname_block,
(int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
filesize -= actsize;
actsize -= pos;
memcpy(buffer, get_contents_vfatname_block + pos, actsize);
*gotsize += actsize;
if (!filesize)
return 0;
buffer += actsize;
curclust = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
debug("Invalid FAT entry\n");
return 0;
}
}
actsize = bytesperclust;
endclust = curclust;
do {
/* search for consecutive clusters */
while (actsize < filesize) {
newclust = get_fatent(mydata, endclust);
if ((newclust - 1) != endclust)
goto getit;
if (CHECK_CLUST(newclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", newclust);
debug("Invalid FAT entry\n");
return 0;
}
endclust = newclust;
actsize += bytesperclust;
}
/* get remaining bytes */
actsize = filesize;
if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
*gotsize += actsize;
return 0;
getit:
if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
*gotsize += (int)actsize;
filesize -= actsize;
buffer += actsize;
curclust = get_fatent(mydata, endclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
printf("Invalid FAT entry\n");
return 0;
}
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 slot2str(dir_slot *slotptr, char *l_name, int *idx)
{
int j;
for (j = 0; j <= 8; j += 2) {
l_name[*idx] = slotptr->name0_4[j];
if (l_name[*idx] == 0x00)
return 1;
(*idx)++;
}
for (j = 0; j <= 10; j += 2) {
l_name[*idx] = slotptr->name5_10[j];
if (l_name[*idx] == 0x00)
return 1;
(*idx)++;
}
for (j = 0; j <= 2; j += 2) {
l_name[*idx] = slotptr->name11_12[j];
if (l_name[*idx] == 0x00)
return 1;
(*idx)++;
}
return 0;
}
/*
* Extract the full long filename starting at 'retdent' (which is really
* a slot) into 'l_name'. If successful also copy the real directory entry
* into 'retdent'
* Return 0 on success, -1 otherwise.
*/
static int
get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
dir_entry *retdent, char *l_name)
{
dir_entry *realdent;
dir_slot *slotptr = (dir_slot *)retdent;
__u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
PREFETCH_BLOCKS :
mydata->clust_size);
__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
int idx = 0;
if (counter > VFAT_MAXSEQ) {
debug("Error: VFAT name is too long\n");
return -1;
}
while ((__u8 *)slotptr < buflimit) {
if (counter == 0)
break;
if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
return -1;
slotptr++;
counter--;
}
if ((__u8 *)slotptr >= buflimit) {
dir_slot *slotptr2;
if (curclust == 0)
return -1;
curclust = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
printf("Invalid FAT entry\n");
return -1;
}
if (get_cluster(mydata, curclust, get_contents_vfatname_block,
mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return -1;
}
slotptr2 = (dir_slot *)get_contents_vfatname_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
return -1;
slotptr2++;
counter--;
}
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
} else {
/* Save the real directory entry */
realdent = (dir_entry *)slotptr;
}
do {
slotptr--;
if (slot2str(slotptr, l_name, &idx))
break;
} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
l_name[idx] = '\0';
if (*l_name == DELETED_FLAG)
*l_name = '\0';
else if (*l_name == aRING)
*l_name = DELETED_FLAG;
downcase(l_name);
/* Return the real directory entry */
memcpy(retdent, realdent, sizeof(dir_entry));
return 0;
}
/* Calculate short name checksum */
static __u8 mkcksum(const char name[8], const char ext[3])
{
int i;
__u8 ret = 0;
for (i = 0; i < 8; i++)
ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
for (i = 0; i < 3; i++)
ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
return ret;
}
/*
* Get the directory entry associated with 'filename' from the directory
* starting at 'startsect'
*/
__u8 get_dentfromdir_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
char *filename, dir_entry *retdent,
int dols)
{
__u16 prevcksum = 0xffff;
__u32 curclust = START(retdent);
int files = 0, dirs = 0;
debug("get_dentfromdir: %s\n", filename);
while (1) {
dir_entry *dentptr;
int i;
if (get_cluster(mydata, curclust, get_dentfromdir_block,
mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return NULL;
}
dentptr = (dir_entry *)get_dentfromdir_block;
for (i = 0; i < DIRENTSPERCLUST; i++) {
char s_name[14], l_name[VFAT_MAXLEN_BYTES];
l_name[0] = '\0';
if (dentptr->name[0] == DELETED_FLAG) {
dentptr++;
continue;
}
if ((dentptr->attr & ATTR_VOLUME)) {
if (vfat_enabled &&
(dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
prevcksum = ((dir_slot *)dentptr)->alias_checksum;
get_vfatname(mydata, curclust,
get_dentfromdir_block,
dentptr, l_name);
if (dols) {
int isdir;
char dirc;
int doit = 0;
isdir = (dentptr->attr & ATTR_DIR);
if (isdir) {
dirs++;
dirc = '/';
doit = 1;
} else {
dirc = ' ';
if (l_name[0] != 0) {
files++;
doit = 1;
}
}
if (doit) {
if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
l_name,
dirc);
} else {
printf(" %s%c\n",
l_name,
dirc);
}
}
dentptr++;
continue;
}
debug("vfatname: |%s|\n", l_name);
} else {
/* Volume label or VFAT entry */
dentptr++;
continue;
}
}
if (dentptr->name[0] == 0) {
if (dols) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
}
debug("Dentname == NULL - %d\n", i);
return NULL;
}
if (vfat_enabled) {
__u8 csum = mkcksum(dentptr->name, dentptr->ext);
if (dols && csum == prevcksum) {
prevcksum = 0xffff;
dentptr++;
continue;
}
}
get_name(dentptr, s_name);
if (dols) {
int isdir = (dentptr->attr & ATTR_DIR);
char dirc;
int doit = 0;
if (isdir) {
dirs++;
dirc = '/';
doit = 1;
} else {
dirc = ' ';
if (s_name[0] != 0) {
files++;
doit = 1;
}
}
if (doit) {
if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
s_name, dirc);
} else {
printf(" %s%c\n",
s_name, dirc);
}
}
dentptr++;
continue;
}
if (strcmp(filename, s_name)
&& strcmp(filename, l_name)) {
debug("Mismatch: |%s|%s|\n", s_name, l_name);
dentptr++;
continue;
}
memcpy(retdent, dentptr, sizeof(dir_entry));
debug("DentName: %s", s_name);
debug(", start: 0x%x", START(dentptr));
debug(", size: 0x%x %s\n",
FAT2CPU32(dentptr->size),
(dentptr->attr & ATTR_DIR) ? "(DIR)" : "");
return retdent;
}
curclust = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
printf("Invalid FAT entry\n");
return NULL;
}
}
return NULL;
}
/*
* Read boot sector and volume info from a FAT filesystem
*/
static int
read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
{
__u8 *block;
volume_info *vistart;
int ret = 0;
if (cur_dev == NULL) {
debug("Error: no device selected\n");
return -1;
}
block = memalign(ARCH_DMA_MINALIGN, cur_dev->blksz);
if (block == NULL) {
debug("Error: allocating block\n");
return -1;
}
if (disk_read(0, 1, block) < 0) {
debug("Error: reading block\n");
goto fail;
}
memcpy(bs, block, sizeof(boot_sector));
bs->reserved = FAT2CPU16(bs->reserved);
bs->fat_length = FAT2CPU16(bs->fat_length);
bs->secs_track = FAT2CPU16(bs->secs_track);
bs->heads = FAT2CPU16(bs->heads);
bs->total_sect = FAT2CPU32(bs->total_sect);
/* FAT32 entries */
if (bs->fat_length == 0) {
/* Assume FAT32 */
bs->fat32_length = FAT2CPU32(bs->fat32_length);
bs->flags = FAT2CPU16(bs->flags);
bs->root_cluster = FAT2CPU32(bs->root_cluster);
bs->info_sector = FAT2CPU16(bs->info_sector);
bs->backup_boot = FAT2CPU16(bs->backup_boot);
vistart = (volume_info *)(block + sizeof(boot_sector));
*fatsize = 32;
} else {
vistart = (volume_info *)&(bs->fat32_length);
*fatsize = 0;
}
memcpy(volinfo, vistart, sizeof(volume_info));
if (*fatsize == 32) {
if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
goto exit;
} else {
if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
*fatsize = 12;
goto exit;
}
if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
*fatsize = 16;
goto exit;
}
}
debug("Error: broken fs_type sign\n");
fail:
ret = -1;
exit:
free(block);
return ret;
}
__u8 do_fat_read_at_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
loff_t maxsize, int dols, int dogetsize, loff_t *size)
{
char fnamecopy[2048];
boot_sector bs;
volume_info volinfo;
fsdata datablock;
fsdata *mydata = &datablock;
dir_entry *dentptr = NULL;
__u16 prevcksum = 0xffff;
char *subname = "";
__u32 cursect;
int idx, isdir = 0;
int files = 0, dirs = 0;
int ret = -1;
int firsttime;
__u32 root_cluster = 0;
__u32 read_blk;
int rootdir_size = 0;
int buffer_blk_cnt;
int do_read;
__u8 *dir_ptr;
if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
debug("Error: reading boot sector\n");
return -1;
}
if (mydata->fatsize == 32) {
root_cluster = bs.root_cluster;
mydata->fatlength = bs.fat32_length;
} else {
mydata->fatlength = bs.fat_length;
}
mydata->fat_sect = bs.reserved;
cursect = mydata->rootdir_sect
= mydata->fat_sect + mydata->fatlength * bs.fats;
mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
mydata->clust_size = bs.cluster_size;
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->fatsize == 32) {
mydata->data_begin = mydata->rootdir_sect -
(mydata->clust_size * 2);
} else {
rootdir_size = ((bs.dir_entries[1] * (int)256 +
bs.dir_entries[0]) *
sizeof(dir_entry)) /
mydata->sect_size;
mydata->data_begin = mydata->rootdir_sect +
rootdir_size -
(mydata->clust_size * 2);
}
mydata->fatbufnum = -1;
mydata->fat_dirty = 0;
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);
root_reparse:
if (*fnamecopy == '\0') {
if (!dols)
goto exit;
dols = LS_ROOT;
} else if ((idx = dirdelim(fnamecopy)) >= 0) {
isdir = 1;
fnamecopy[idx] = '\0';
subname = fnamecopy + idx + 1;
/* Handle multiple delimiters */
while (ISDIRDELIM(*subname))
subname++;
} else if (dols) {
isdir = 1;
}
buffer_blk_cnt = 0;
firsttime = 1;
while (1) {
int i;
if (mydata->fatsize == 32 || firsttime) {
dir_ptr = do_fat_read_at_block;
firsttime = 0;
} else {
/**
* FAT16 sector buffer modification:
* Each loop, the second buffered block is moved to
* the buffer begin, and two next sectors are read
* next to the previously moved one. So the sector
* buffer keeps always 3 sectors for fat16.
* And the current sector is the buffer second sector
* beside the "firsttime" read, when it is the first one.
*
* PREFETCH_BLOCKS is 2 for FAT16 == loop[0:1]
* n = computed root dir sector
* loop | cursect-1 | cursect | cursect+1 |
* 0 | sector n+0 | sector n+1 | none |
* 1 | none | sector n+0 | sector n+1 |
* 0 | sector n+1 | sector n+2 | sector n+3 |
* 1 | sector n+3 | ...
*/
dir_ptr = (do_fat_read_at_block + mydata->sect_size);
memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
}
do_read = 1;
if (mydata->fatsize == 32 && buffer_blk_cnt)
do_read = 0;
if (do_read) {
read_blk = (mydata->fatsize == 32) ?
mydata->clust_size : PREFETCH_BLOCKS;
debug("FAT read(sect=%d, cnt:%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
cursect, read_blk, mydata->clust_size, DIRENTSPERBLOCK);
if (disk_read(cursect, read_blk, dir_ptr) < 0) {
debug("Error: reading rootdir block\n");
goto exit;
}
dentptr = (dir_entry *)dir_ptr;
}
for (i = 0; i < DIRENTSPERBLOCK; i++) {
char s_name[14], l_name[VFAT_MAXLEN_BYTES];
__u8 csum;
l_name[0] = '\0';
if (dentptr->name[0] == DELETED_FLAG) {
dentptr++;
continue;
}
if (vfat_enabled)
csum = mkcksum(dentptr->name, dentptr->ext);
if (dentptr->attr & ATTR_VOLUME) {
if (vfat_enabled &&
(dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
prevcksum =
((dir_slot *)dentptr)->alias_checksum;
get_vfatname(mydata,
root_cluster,
dir_ptr,
dentptr, l_name);
if (dols == LS_ROOT) {
char dirc;
int doit = 0;
int isdir =
(dentptr->attr & ATTR_DIR);
if (isdir) {
dirs++;
dirc = '/';
doit = 1;
} else {
dirc = ' ';
if (l_name[0] != 0) {
files++;
doit = 1;
}
}
if (doit) {
if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
l_name,
dirc);
} else {
printf(" %s%c\n",
l_name,
dirc);
}
}
dentptr++;
continue;
}
debug("Rootvfatname: |%s|\n",
l_name);
} else {
/* Volume label or VFAT entry */
dentptr++;
continue;
}
} else if (dentptr->name[0] == 0) {
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;
}
else if (vfat_enabled &&
dols == LS_ROOT && csum == prevcksum) {
prevcksum = 0xffff;
dentptr++;
continue;
}
get_name(dentptr, s_name);
if (dols == LS_ROOT) {
int isdir = (dentptr->attr & ATTR_DIR);
char dirc;
int doit = 0;
if (isdir) {
dirc = '/';
if (s_name[0] != 0) {
dirs++;
doit = 1;
}
} else {
dirc = ' ';
if (s_name[0] != 0) {
files++;
doit = 1;
}
}
if (doit) {
if (dirc == ' ') {
printf(" %8u %s%c\n",
FAT2CPU32(dentptr->size),
s_name, dirc);
} else {
printf(" %s%c\n",
s_name, dirc);
}
}
dentptr++;
continue;
}
if (strcmp(fnamecopy, s_name)
&& strcmp(fnamecopy, l_name)) {
debug("RootMismatch: |%s|%s|\n", s_name,
l_name);
dentptr++;
continue;
}
if (isdir && !(dentptr->attr & ATTR_DIR))
goto exit;
debug("RootName: %s", s_name);
debug(", start: 0x%x", START(dentptr));
debug(", size: 0x%x %s\n",
FAT2CPU32(dentptr->size),
isdir ? "(DIR)" : "");
goto rootdir_done; /* We got a match */
}
debug("END LOOP: buffer_blk_cnt=%d clust_size=%d\n", buffer_blk_cnt,
mydata->clust_size);
/*
* On FAT32 we must fetch the FAT entries for the next
* root directory clusters when a cluster has been
* completely processed.
*/
++buffer_blk_cnt;
int rootdir_end = 0;
if (mydata->fatsize == 32) {
if (buffer_blk_cnt == mydata->clust_size) {
int nxtsect = 0;
int nxt_clust = 0;
nxt_clust = get_fatent(mydata, root_cluster);
rootdir_end = CHECK_CLUST(nxt_clust, 32);
nxtsect = mydata->data_begin +
(nxt_clust * mydata->clust_size);
root_cluster = nxt_clust;
cursect = nxtsect;
buffer_blk_cnt = 0;
}
} else {
if (buffer_blk_cnt == PREFETCH_BLOCKS)
buffer_blk_cnt = 0;
rootdir_end = (++cursect - mydata->rootdir_sect >=
rootdir_size);
}
/* If end of rootdir reached */
if (rootdir_end) {
if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
*size = 0;
}
goto exit;
}
}
rootdir_done:
firsttime = 1;
while (isdir) {
int startsect = mydata->data_begin
+ START(dentptr) * mydata->clust_size;
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)
*size = 0;
goto exit;
}
if (isdir && !(dentptr->attr & ATTR_DIR))
goto exit;
/*
* If we are looking for a directory, and found a directory
* type entry, and the entry is for the root directory (as
* denoted by a cluster number of 0), jump back to the start
* of the function, since at least on FAT12/16, the root dir
* lives in a hard-coded location and needs special handling
* to parse, rather than simply following the cluster linked
* list in the FAT, like other directories.
*/
if (isdir && (dentptr->attr & ATTR_DIR) && !START(dentptr)) {
/*
* Modify the filename to remove the prefix that gets
* back to the root directory, so the initial root dir
* parsing code can continue from where we are without
* confusion.
*/
strcpy(fnamecopy, nextname ?: "");
/*
* Set up state the same way as the function does when
* first started. This is required for the root dir
* parsing code operates in its expected environment.
*/
subname = "";
cursect = mydata->rootdir_sect;
isdir = 0;
goto root_reparse;
}
if (idx >= 0)
subname = nextname;
}
if (dogetsize) {
*size = FAT2CPU32(dentptr->size);
ret = 0;
} else {
ret = get_contents(mydata, dentptr, pos, buffer, maxsize, size);
}
debug("Size: %u, got: %llu\n", FAT2CPU32(dentptr->size), *size);
exit:
free(mydata->fatbuf);
return ret;
}
int do_fat_read(const char *filename, void *buffer, loff_t maxsize, int dols,
loff_t *actread)
{
return do_fat_read_at(filename, 0, buffer, maxsize, dols, 0, actread);
}
int file_fat_detectfs(void)
{
boot_sector bs;
volume_info volinfo;
int fatsize;
char vol_label[12];
if (cur_dev == NULL) {
printf("No current device\n");
return 1;
}
#if defined(CONFIG_CMD_IDE) || \
defined(CONFIG_CMD_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 (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 file_fat_ls(const char *dir)
{
loff_t size;
return do_fat_read(dir, NULL, 0, LS_YES, &size);
}
int fat_exists(const char *filename)
{
int ret;
loff_t size;
ret = do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, &size);
return ret == 0;
}
int fat_size(const char *filename, loff_t *size)
{
return do_fat_read_at(filename, 0, NULL, 0, LS_NO, 1, size);
}
int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
loff_t maxsize, loff_t *actread)
{
printf("reading %s\n", filename);
return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO, 0,
actread);
}
int file_fat_read(const char *filename, void *buffer, int maxsize)
{
loff_t actread;
int ret;
ret = file_fat_read_at(filename, 0, buffer, maxsize, &actread);
if (ret)
return ret;
else
return actread;
}
int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
loff_t *actread)
{
int ret;
ret = file_fat_read_at(filename, offset, buf, len, actread);
if (ret)
printf("** Unable to read file %s **\n", filename);
return ret;
}
void fat_close(void)
{
}
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