[U-Boot] [PATCH v3] FAT: Make it possible to read from any file position
Benoît Thébaudeau
benoit.thebaudeau at advansee.com
Tue Sep 18 20:14:56 CEST 2012
When storage devices contain files larger than the embedded RAM, it is useful to
be able to read these files by chunks, e.g. for a software update to the
embedded NAND Flash from an external storage device (USB stick, SD card, etc.).
Hence, this patch makes it possible by adding a new FAT API to read files from a
given position. This patch also adds this feature to the fatload command.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
Cc: Tom Rini <trini at ti.com>
Cc: Wolfgang Denk <wd at denx.de>
---
Changes for v2:
- Add missing variable renaming to fat_write.c.
Changes for v3:
- Make this new feature available through the fatload command.
.../common/cmd_fat.c | 25 +++--
.../fs/fat/fat.c | 98 ++++++++++++++++----
.../fs/fat/fat_write.c | 18 ++--
.../include/fat.h | 2 +
4 files changed, 105 insertions(+), 38 deletions(-)
diff --git u-boot-037e9d3.orig/common/cmd_fat.c u-boot-037e9d3/common/cmd_fat.c
index 559a16d..2e34c54 100644
--- u-boot-037e9d3.orig/common/cmd_fat.c
+++ u-boot-037e9d3/common/cmd_fat.c
@@ -37,7 +37,8 @@ int do_fat_fsload (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
long size;
unsigned long offset;
- unsigned long count;
+ unsigned long count = 0;
+ unsigned long pos = 0;
char buf [12];
block_dev_desc_t *dev_desc=NULL;
int dev=0;
@@ -46,7 +47,7 @@ int do_fat_fsload (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
if (argc < 5) {
printf( "usage: fatload <interface> <dev[:part]> "
- "<addr> <filename> [bytes]\n");
+ "<addr> <filename> [bytes [pos]]\n");
return 1;
}
@@ -69,11 +70,11 @@ int do_fat_fsload (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
return 1;
}
offset = simple_strtoul(argv[3], NULL, 16);
- if (argc == 6)
+ if (argc >= 6)
count = simple_strtoul(argv[5], NULL, 16);
- else
- count = 0;
- size = file_fat_read(argv[4], (unsigned char *)offset, count);
+ if (argc >= 7)
+ pos = simple_strtoul(argv[6], NULL, 16);
+ size = file_fat_read_at(argv[4], pos, (unsigned char *)offset, count);
if(size==-1) {
printf("\n** Unable to read \"%s\" from %s %d:%d **\n",
@@ -91,11 +92,15 @@ int do_fat_fsload (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
U_BOOT_CMD(
- fatload, 6, 0, do_fat_fsload,
+ fatload, 7, 0, do_fat_fsload,
"load binary file from a dos filesystem",
- "<interface> <dev[:part]> <addr> <filename> [bytes]\n"
- " - load binary file 'filename' from 'dev' on 'interface'\n"
- " to address 'addr' from dos filesystem"
+ "<interface> <dev[:part]> <addr> <filename> [bytes [pos]]\n"
+ " - Load binary file 'filename' from 'dev' on 'interface'\n"
+ " to address 'addr' from dos filesystem.\n"
+ " 'pos' gives the file position to start loading from.\n"
+ " If 'pos' is omitted, 0 is used. 'pos' requires 'bytes'.\n"
+ " 'bytes' gives the size to load. If 'bytes' is 0 or omitted,\n"
+ " the load stops on end of file."
);
int do_fat_ls (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
diff --git u-boot-037e9d3.orig/fs/fat/fat.c u-boot-037e9d3/fs/fat/fat.c
index f7bb1da..c8beb30 100644
--- u-boot-037e9d3.orig/fs/fat/fat.c
+++ u-boot-037e9d3/fs/fat/fat.c
@@ -328,13 +328,16 @@ get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
}
/*
- * Read at most 'maxsize' bytes from the file associated with 'dentptr'
+ * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
* into 'buffer'.
* Return the number of bytes read or -1 on fatal errors.
*/
+__u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
+ __aligned(ARCH_DMA_MINALIGN);
+
static long
-get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
- unsigned long maxsize)
+get_contents(fsdata *mydata, dir_entry *dentptr, unsigned long pos,
+ __u8 *buffer, unsigned long maxsize)
{
unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
@@ -344,12 +347,59 @@ get_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
debug("Filesize: %ld bytes\n", filesize);
- if (maxsize > 0 && filesize > maxsize)
- filesize = maxsize;
+ if (pos >= filesize) {
+ debug("Read position past EOF: %lu\n", pos);
+ return gotsize;
+ }
+
+ if (maxsize > 0 && filesize > pos + maxsize)
+ filesize = pos + maxsize;
debug("%ld 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 gotsize;
+ }
+ actsize += bytesperclust;
+ }
+
+ /* actsize > pos */
+ actsize -= bytesperclust;
+ filesize -= actsize;
+ pos -= actsize;
+
+ /* align to beginning of next cluster if any */
+ if (pos) {
+ actsize = min(filesize, 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 gotsize;
+ 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 gotsize;
+ }
+ }
+
+ actsize = bytesperclust;
endclust = curclust;
do {
@@ -433,9 +483,6 @@ static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
* into 'retdent'
* Return 0 on success, -1 otherwise.
*/
-__u8 get_vfatname_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
-
static int
get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
dir_entry *retdent, char *l_name)
@@ -474,13 +521,13 @@ get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
return -1;
}
- if (get_cluster(mydata, curclust, get_vfatname_block,
+ 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_vfatname_block;
+ slotptr2 = (dir_slot *)get_contents_vfatname_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
@@ -491,7 +538,7 @@ get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
- while ((__u8 *)slotptr2 > get_vfatname_block) {
+ while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
@@ -770,11 +817,12 @@ exit:
return ret;
}
-__u8 do_fat_read_block[MAX_CLUSTSIZE]
+__u8 do_fat_read_at_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
long
-do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
+do_fat_read_at(const char *filename, unsigned long pos, void *buffer,
+ unsigned long maxsize, int dols)
{
char fnamecopy[2048];
boot_sector bs;
@@ -888,12 +936,12 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
(mydata->fatsize == 32) ?
(mydata->clust_size) :
PREFETCH_BLOCKS,
- do_fat_read_block) < 0) {
+ do_fat_read_at_block) < 0) {
debug("Error: reading rootdir block\n");
goto exit;
}
- dentptr = (dir_entry *) do_fat_read_block;
+ dentptr = (dir_entry *) do_fat_read_at_block;
}
for (i = 0; i < DIRENTSPERBLOCK; i++) {
@@ -913,7 +961,7 @@ do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
get_vfatname(mydata,
root_cluster,
- do_fat_read_block,
+ do_fat_read_at_block,
dentptr, l_name);
if (dols == LS_ROOT) {
@@ -1116,7 +1164,7 @@ rootdir_done:
}
}
- ret = get_contents(mydata, dentptr, buffer, maxsize);
+ ret = get_contents(mydata, dentptr, pos, buffer, maxsize);
debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
exit:
@@ -1124,6 +1172,12 @@ exit:
return ret;
}
+long
+do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
+{
+ return do_fat_read_at(filename, 0, buffer, maxsize, dols);
+}
+
int file_fat_detectfs(void)
{
boot_sector bs;
@@ -1192,8 +1246,14 @@ int file_fat_ls(const char *dir)
return do_fat_read(dir, NULL, 0, LS_YES);
}
-long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
+long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
+ unsigned long maxsize)
{
printf("reading %s\n", filename);
- return do_fat_read(filename, buffer, maxsize, LS_NO);
+ return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO);
+}
+
+long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
+{
+ return file_fat_read_at(filename, 0, buffer, maxsize);
}
diff --git u-boot-037e9d3.orig/fs/fat/fat_write.c u-boot-037e9d3/fs/fat/fat_write.c
index a6181e7..5829adf 100644
--- u-boot-037e9d3.orig/fs/fat/fat_write.c
+++ u-boot-037e9d3/fs/fat/fat_write.c
@@ -328,7 +328,7 @@ static void flush_dir_table(fsdata *mydata, dir_entry **dentptr);
static void
fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
{
- dir_slot *slotptr = (dir_slot *)get_vfatname_block;
+ dir_slot *slotptr = (dir_slot *)get_contents_vfatname_block;
__u8 counter = 0, checksum;
int idx = 0, ret;
char s_name[16];
@@ -373,7 +373,7 @@ static __u32 dir_curclust;
* a slot) into 'l_name'. If successful also copy the real directory entry
* into 'retdent'
* If additional adjacent cluster for directory entries is read into memory,
- * then 'get_vfatname_block' is copied into 'get_dentfromdir_block' and
+ * then 'get_contents_vfatname_block' is copied into 'get_dentfromdir_block' and
* the location of the real directory entry is returned by 'retdent'
* Return 0 on success, -1 otherwise.
*/
@@ -416,13 +416,13 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
dir_curclust = curclust;
- if (get_cluster(mydata, curclust, get_vfatname_block,
+ 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_vfatname_block;
+ slotptr2 = (dir_slot *)get_contents_vfatname_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
@@ -433,7 +433,7 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
- while ((__u8 *)slotptr2 > get_vfatname_block) {
+ while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
@@ -459,9 +459,9 @@ get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
*retdent = realdent;
if (slotptr2) {
- memcpy(get_dentfromdir_block, get_vfatname_block,
+ memcpy(get_dentfromdir_block, get_contents_vfatname_block,
mydata->clust_size * mydata->sect_size);
- cur_position = (__u8 *)realdent - get_vfatname_block;
+ cur_position = (__u8 *)realdent - get_contents_vfatname_block;
*retdent = (dir_entry *) &get_dentfromdir_block[cur_position];
}
@@ -980,11 +980,11 @@ static int do_fat_write(const char *filename, void *buffer,
if (disk_read(cursect,
(mydata->fatsize == 32) ?
(mydata->clust_size) :
- PREFETCH_BLOCKS, do_fat_read_block) < 0) {
+ PREFETCH_BLOCKS, do_fat_read_at_block) < 0) {
debug("Error: reading rootdir block\n");
goto exit;
}
- dentptr = (dir_entry *) do_fat_read_block;
+ dentptr = (dir_entry *) do_fat_read_at_block;
name_len = strlen(filename);
if (name_len >= VFAT_MAXLEN_BYTES)
diff --git u-boot-037e9d3.orig/include/fat.h u-boot-037e9d3/include/fat.h
index f1b4a0d..cc85b06 100644
--- u-boot-037e9d3.orig/include/fat.h
+++ u-boot-037e9d3/include/fat.h
@@ -208,6 +208,8 @@ file_read_func file_fat_read;
int file_cd(const char *path);
int file_fat_detectfs(void);
int file_fat_ls(const char *dir);
+long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
+ unsigned long maxsize);
long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
const char *file_getfsname(int idx);
int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
More information about the U-Boot
mailing list