x-load throws 'ECC failed' on nand read

Rahul Prashant Shukla

Other Parts Discussed in Thread: AM3517

Hi,

I am using LogicPD am3517 evm board. I have build the 'TI X-Loader 1.51' and 'TI U-Boot 2010.06'. I am doing nand_read (using API nand_read_block()) in x-loader to read a nand flash location (say 0xAAAAA). This nand location I modify in u-boot code. Initially when complete NAND is erased and flashed with x-load/u-boot. x-load reads some junk data at 0xAAAAA and proceed with u-boot loading. Now when u-boot writes some data at location 0xAAAAA and I reset the board, x-load fails while reading this NAND location with ECC failed error. u-boot successfully writes and reads back the data (for verification) but x-load fails to understand the data.

Is ECC algorithm implementation is different b/w x-load & u-boot? I flash the x-loader and u-boot with 'nandecc hw'.

Any help?

Thanks.

over 13 years ago

0 Michael T over 13 years ago

TI__Expert 6735 points

Rahul:

x-load needs to be built for a specific ECC format - as described here:

http://processors.wiki.ti.com/index.php/AM35x-OMAP35x-PSP_04.02.00.07_UserGuide#Selecting_ECC_scheme

Those instructions are valid for AM3517 SDK 05.02.00.00 which used PSP 04.02.00.07.

You can tell your version by looking at the folder names under ./board-support in your installed EZSDK.

Regards,

Michael T

0 Vaibhav Hiremath over 13 years ago

TI__Expert 8180 points

I did not understand what exactly you are trying to do here, probably your sequence of operation is not clear above. Just FYI, by default when u-boot boots up, it configured the default ECC for SW ecc scheme (If I remember correctly). You may be flashing x-loader/u-boot using "hw" ecc schema, but what about ecc selection when you are writing @ 0xAAAAA location?

Thanks,

Vaibhav

0 Rahul Prashant Shukla over 13 years ago in reply to Michael T

Prodigy 60 points

I looked into u-boot code, in board_nand_init(), 4 bit ECC is being set. So I compiled x-loader with 4-bit BCH ECC. and it worked.

Thanks for the help.

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x-load throws 'ECC failed' on nand read