Scrubbing Onenand - Texas Instruments OMAP35 Series User Manual

If a bad block is encountered during the read operation, it is skipped and the
read operation continues from next 'good' block.
For example, to read 0x40000 bytes from OneNAND - starting at block 32 (offset
0x400000) to memory buffer at address 0x80000000:

3.4.5. Scrubbing OneNAND

This command operation is similar to the erase command, with a difference
that it doesn't care for bad blocks. It attempts to erase all blocks in the specified
address range.
To scrub OneNAND blocks in the address range:
24
Important
If the read fails on ECC check, the block where the failure occurred is marked
bad and read operation is aborted. The command needs to be re- executed
to complete the read operation. But, the data in just marked bad block is
irrecoverably lost. The offset and length for reading have to be page aligned
else the command will abort.
OMAP3EVM# onenand read 0x80000000 0x400000 0x40000
OMAP3EVM# onenand scrub <stoffaddr> <eoffaddr>
or
OMAP3EVM# onenand scrub block <stblknum-endblknum>
Note
This is a new command.
Important
The command does not check whether the block is a user marked or factory
marked bad block. This command fails on a factory marked bad block.
Important
If the erase operation fails, the block is marked as bad and the command
aborts. The command needs to be re-executed for the remaining blocks in the
range.
Platform Support Products
U-Boot
Scrubbing OneNAND
Version 02.01.01.08