DM368 Linux NAND ECC error

g.f.

Hi,

We are using DM368 with DVSDKv4.02 and having NAND ECC error problem.
Using Micron 8bit NAND Flash and supports 4bit ECC.

With a customer board, UBL, U-boot, uImage, JFFS2(or UBIFS) are first flashed to NAND, using SD Boot.
Therefore UBL, U-boot, uImage, and Filesystem to write to the NAND is saved in SD card beforehand.
Flashing to the NAND is performed from U-boot.

After flashing the NAND, we reboot the board using NAND Boot.
UBL, U-boot, kernel will boot up successfully but
while mounting root filesystem(JFFS2 or UBIFS) NAND ECC errors occur frequently.

Moreover, when updating the NAND u-boot from kernel and then reboot the board,
U-boot will not boot successfully.
It seems that NAND flashing program of kernel is not operating correctly.

When I checked with the trial by DM368EVM,
NAND ECC error occur after mounting root filesystem.
I tested with the following method.
******************************************************************************
Booting from SD card and flashing JFFS2 to NAND from the u-boot.
Then reboot UBL, U-boot, uImage from SD card,
and JFFS2 filesystem are mounted from NAND Flash, NAND ECC occur.

I will attach the log file to this post.

Tested by following UBL, U-boot, uImage and JFFS2:
===JFFS2===
Uncompress the"ti-dvsdk_dm368-evm_4_02_00_06/filesystem/arago-base-tisdk-image-dm368-evm.tar.gz"
and created as follow:
mkfs.jffs2 -l -q -n -e 128 -r ./rfs/ -o ./jffs2.bin -p 131072

===UBL===
"ti-dvsdk_dm368-evm_4_02_00_06/psp/board_utilities/serial_flash/UBL_DM36x_SDMMC_ARM432_DDR340_OSC24.bin"

===U-boot, uImage===
Created after executing "ti-dvsdk_dm368-evm_4_02_00_06/setup.sh"
*********************************************************************************

Please give me an advice for this NAND ECC error.

best regards,
g.f.

over 12 years ago

0 1330hayacool7102 over 12 years ago

Guru 10655 points

pls verify the info about the position for bad block, ecc in oob first,

then check if the program write the related info in the correct position inside oob.

0 bonggyu Choi over 12 years ago in reply to 1330hayacool7102

Intellectual 460 points

Hi jack,

In my experience, ECC skim should be same in UBL, u-boot, kernel. So, you should check source code on those.

then, when you write images(kernel, root file system), you prefer to initialize memory region of copying images to 0xFF.

and when you decide size of writting area of nand flash, you prefer to decide size to exact size of image.

BR,

Choi

0 1330hayacool7102 over 12 years ago in reply to bonggyu Choi

Guru 10655 points

Uboot's ecc skim should be the same as UBL when flashing uboot (because UBL read)

kernel's ecc skim should be the same as Uboot when flashing images (because Uboot read)

root file system's ecc skim should be the same as kernel when saving data (because kernel read)

the ecc skims of the above could be the same or not.(what we need to make sure is the read/write with the same ecc skim)

generally it would be convenient if all are the same except you have some specific usage

hi g.f,

is your ecc skim the same in UBL, Uboot, kernel?

is your ecc location inside oob the same in UBL, Uboot, kernel?

Moreover, when updating the NAND u-boot from kernel and then reboot the board,
U-boot will not boot successfully.

- pls check if there're some overhead in uboot. if yes, pls add overhead when flashing uboot.

this should be another problem independent of ecc's issue.

0 g.f. over 12 years ago in reply to 1330hayacool7102

Guru 15520 points

Hi,

Thank you for the response.

My understanding is that ecc skim(4bit HW ecc) and ecc layout is the same in UBL, Uboot, kernel
because we are using UBL, u-boot, uImage, JFFS2.bin with no change which contain in DVSDKv4.02.
Am I wrong?

best regards,
g.f.

0 bonggyu Choi over 12 years ago in reply to g.f.

Intellectual 460 points

Hi,

Did you try nand scrub before nand write for wrting area?

BR,

Choi

0 g.f. over 12 years ago in reply to bonggyu Choi

Guru 15520 points

Hi,

Yes, I did nand scrub before nand write.

best regards,

g.f.

0 Leon Pollak over 11 years ago in reply to g.f.

Intellectual 960 points

Hello.

What is the final result from this issue?
Have you overcome the problem?

Thanks.

0 tek4 over 9 years ago in reply to Leon Pollak

Intellectual 700 points

We have the same problem now. Was there a solution ?

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DM368 Linux NAND ECC error