nandwrite/ubi memory corruption?

[Michal Ludvig <mludvig@logix.net.nz>]

Hi all,

I've got an ARM board with 64MB of NAND flash with 3 logical partitions
and am experiencing (probably) memory corruption of UBI/UBIFS on
/dev/mtd2 after writing data with nandwrite to /dev/mtd1.

These are my logical partitions on NAND:

S3C24XX NAND Driver, (c) 2004 Simtec Electronics
s3c2410-nand s3c2410-nand: Tacls=3, 30ns Twrph0=7 70ns, Twrph1=3 30ns
NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB
3,3V 8-bit)
Scanning device for bad blocks
Creating 3 MTD partitions on "NAND 64MiB 3,3V 8-bit":
0x00000000-0x00050000 : "boot"
0x00050000-0x00220000 : "kernel"
0x00220000-0x04000000 : "ubi"
s3c2410-nand s3c2410-nand: clock idle support enabled



I use u-boot 1.1.4 as the bootloader and 2.6.27 as the kernel. The
kernel image size is 1492552 bytes, that should fit into the kernel
partition as far as I can tell.

When I load the kernel in u-boot and write into NAND with 'nandw'
command of u-boot it works fine.

However when I use nandwrite from linux it does "something" but
1) the kernel won't boot
2) it probably corrupted the 'ubi' partition:

~ # nandwrite -p /dev/mtd1 uimage26
Writing data to block 0
Writing data to block 4000
[...]
Writing data to block 164000
Writing data to block 168000
Writing data to block 16c000

~ # ls
UBI error: ubi_io_write: error -5 while writing 512 bytes to PEB
2414:15360, written 0 bytes
UBI warning: ubi_eba_write_leb: failed to write data to PEB 2414
UBI: recover PEB 2414, move data to PEB 2428
UBI warning: ubi_io_read_vid_hdr: bad magic number at PEB 2414: 00000000
instead of 55424921
UBI warning: ubi_ro_mode: switch to read-only mode
UBIFS error (pid 224): ubifs_wbuf_sync_nolock: cannot write 512 bytes to
LEB 746:14336
UBIFS error (pid 224): ubifs_bg_wbufs_sync: cannot sync write-buffer,
error -5
UBIFS warning (pid 224): ubifs_ro_mode: switched to read-only mode, error -5

So it experienced some corruption and switched to read-only mode.

Auto-completeing commands in shell doesn't work either:

~ # nandd<tab>
UBIFS error (pid 241): ubifs_read_node: bad node type (0 but expected 9)
UBIFS error (pid 241): ubifs_read_node: bad node at LEB 757:11760
UBIFS error (pid 241): ubifs_iget: failed to read inode 232, error -22
UBIFS error (pid 241): ubifs_lookup: dead directory entry 'nanddump',
error -22

When I reset the board the just written kernel won't boot:

NAND Flash Reading
dst base address          = 0x30100000
Source start block number = 20
Source size  (0x4000*n)   = 0x180000
status 1
## Booting image at 30100000 ...
status 2
Bad Header Checksum
status -2

But after reloading a good kernel into NAND in u-boot and booting it
everything looks ok and I can run 'ls' and 'nanddump' just fine. I can't
tell whether the UBIFS volume is corrupted or not (is there some ubifsck
tool available?) but nothing obvious pops up.

Nandwrite is ~2 days old one from git, kernel is 2.6.27, both compiled
with gcc 3.4.6. CPU is Samsung S3C2410 (ARM920T arch), NAND as above.

So the summary is
1) Writing a kernel image with nandwrite into a MTD partition /dev/mtd1,
where the kernel image is smaller than the partition.
2) Ubi/ubifs using MTD partition /dev/mtd2 gets corrupted (memory only?)
3) The written kernel won't boot. The same one written from u-boot works
fine.

It's all 100% reproducible.

Do you need any other information?

Michal