Add support for "kernel_noload" image types #55
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On FAT32, instead of fetching the cluster numbers from the FAT, the code assumed (incorrectly) that the clusters for the root directory were allocated contiguously. In the result, only the first cluster could be accessed. At the typical cluster size of 8 sectors this caused all accesses to files after the first 128 entries to fail - "fatls" would terminate after 128 files (usually displaying a bogus file name, occasionally even crashing the system), and "fatload" would fail to find any files that were not in the first directory cluster. Signed-off-by: Wolfgang Denk <wd@denx.de> cherry-picked/merged from: u-boot mainline commit 2aa98c6
- reformat - throw out macros like FAT_DPRINT and FAT_DPRINT - remove dead code Signed-off-by: Wolfgang Denk <wd@denx.de> cherry-picked/merged from: u-boot mainline commit 7385c28
The U-Boot code has the following bugs related to the processing of Long File
Name (LFN) entries scattered across several clusters/sectors :
1) get_vfatname() function is designed to gather scattered LFN entries by
cluster chain processing - that doesn't work for FAT12/16 root directory.
In other words, the function expects the following input data:
1.1) FAT32 directory (which is cluster chain based);
OR
1.2) FAT12/16 non-root directory (which is also cluster chain based);
OR
1.3) FAT12/16 root directory (allocated as contiguous sectors area), but
all necessary information MUST be within the input buffer of filesystem cluster
size (thus cluster-chain jump is never initiated).
In order to accomplish the last condition, root directory parsing code in
do_fat_read() uses the following trick: read-out cluster-size block, process
only first sector (512 bytes), then shift 512 forward, read-out cluster-size
block and so on. This works great unless cluster size is equal to 512 bytes
(in a case you have a small partition), or long file name entries are scattered
across three sectors, see 4) for details.
2) Despite of the fact that get_vfatname() supports FAT32 root directory
browsing, do_fat_read() function doesn't send current cluster number correctly,
so root directory look-up doesn't work correctly.
3) get_vfatname() doesn't gather scattered entries correctly also is the case
when all LFN entries are located at the end of the source cluster, but real
directory entry (which must be returned) is at the only beginning of the
next one. No error detected, the resulting directory entry returned contains
a semi-random information (wrong size, wrong start cluster number and so on)
i.e. the entry is not accessible.
4) LFN (VFAT) allows up to 20 entries (slots) each containing 26 bytes (13
UTF-16 code units) to represent a single long file name i.e. up to 520 bytes.
U-Boot allocates 256 bytes buffer instead, i.e. 10 or more LFN slots record
may cause buffer overflow / memory corruption.
Also, it's worth to mention that 20+1 slots occupy 672 bytes space which may
take more than one cluster of 512 bytes (medium-size FAT32 or small FAT16
partition) - get_vfatname() function doesn't support such case as well.
The patch attached fixes these problems in the following way:
- keep using 256 bytes buffer for a long file name, but safely prevent a
possible buffer overflow (skip LFN processing, if it contains 10 or more
slots).
- explicitly specify FAT12/16 root directory parsing buffer size, instead
of relying on cluster size. The value used is a double sector size (to store
current sector and the next one). This fixes the first problem and increases
performance on big FAT12/16 partitions;
- send current cluster number (FAT32) to get_vfatname() during root
directory processing;
- use LFN counter to seek the real directory entry in get_vfatname() - fixes the
third problem;
- skip deleted entries in the root directory (to prevent bogus buffer
overflow detection and LFN counter steps).
Note: it's not advised to split up the patch, because a separate part may
operate incorrectly.
Signed-off-by: Mikhail Zolotaryov <lebon@lebon.org.ua>
cherry-picked/merged from:
u-boot mainline commit 3831530
Fat directory handling didn't check reaching the end of the root directory. It
relied on a stop condition based on a directory entry with a name starting with
a '\0' character. This check in itself is wrong ('\0' indicates free entry, not
end_of_directory) but outside the scope of this fix. For FAT32, the end of the
rootdir is reached when the end of the cluster chain is reached. The code didn't
check this condition and started to read an incorrect cluster. This caused a
subsequent read request of a sector outside the range of the usb stick in
use. On its turn, the usb stick protested with a stall handshake.
Both FAT32 and non-FAT32 (FAT16/FAT12) end or rootdir checks have been put in.
Signed-off-by: Erik Hansen <erik@makarta.com>
cherry-picked/merged from:
u-boot mainline commit 3f270f4
Apple iPod nanos have sector sizes of 2 or 4 KiB, which crashes U-Boot when it tries to read the boot sector into 512-byte buffer situated on stack. Make the FAT code indifferent to the sector size. Signed-off-by: Sergei Shtylyov <sshtylyov@mvista.com> cherry-picked/merged from: u-boot mainline commit ac49777
The code multiples the FAT size in sectors by the sector size and then tries to compare that to the number of sectors in the 'getsize' variable. While fixing this, also change the initial value of 'getsize' as the division of FATBUFSIZE by the sector size gets us FATBUFBLOCKS. Signed-off-by: Sergei Shtylyov <sshtylyov@mvista.com> cherry-picked/merged from: u-boot mainline commit 60b36f0
Currently in do_fat_read() when reading FAT sectors, we have to divide down LINEAR_PREFETCH_SIZE by the sector size, whereas it's defined as 2 sectors worth of bytes. In order to avoid redundant multiplication/division, introduce Signed-off-by: Sergei Shtylyov <sshtylyov@mvista.com> cherry-picked/merged from: u-boot mainline commit 025421e
ATTR_VFAT condition requires multiple bits to be set but the present condition checking in do_fat_read() & get_dentfromdir() ends up passing on even a single bit being set. Signed-off-by: J. Vijayanand <vijayanand.jayaraman@in.bosch.com> Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> cherry-picked/merged from: u-boot mainline commit 206d68f
The VFAT short alias checksum read from a long file name is only overwritten when another long file name appears in a directory list. Until then it renders short file names invisible that have the same checksum. Reset the checksum on first match. Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Martin Mueller <martin.mueller5@de.bosch.com> cherry-picked/merged from: u-boot mainline commit bf34e7d
startblock must be taken into account in order not to read past the end of the FAT. Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Cc: Wolfgang Denk <wd@denx.de> cherry-picked/merged from: u-boot mainline commit 8006dd2
With: fatls mmc 0 /dir/file dir: regular directory file: regular file The previous code read the contents of file as if it were directory entries to list. This patch refuses to list file contents as if it were a folder. Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Cc: Wolfgang Denk <wd@denx.de> cherry-picked/merged from: u-boot mainline commit 7ee46ce
With the previous code, the remaining prefetched sectors were read again after each sector. With this patch, each sector is read only once, thus making the prefetch useful. Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Cc: Wolfgang Denk <wd@denx.de> cherry-picked/merged from: u-boot mainline commit cd1b042
cherry-pick fs/fat fixes from mainline u-boot
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The "kernel_noload" U-Boot image type in newer U-Boot versions allows for booting a kernel in-place without having to specify a load address. The NetBSD kernel uses this feature to share a single kernel image across all FDT-capable ARM boards.