[U-Boot] [PATCH] add explicit bbt creation to commandline

Scott Wood
2010-02-12T17:04:11Z

On Thu, Feb 11, 2010 at 06:49:33PM -0800, Steven Zedeck wrote:
>
> Hi,
> I know this message is about 18 months old. I am using Uboot 2008.10, which
> seems to not include support for creating the Nand BBT (bad block table).
> Was this patch released and if so when? Forgive me as I don't know how to
> find out.
>
> How best to add BBT support to Uboot? I need to have a BBT created such that
> Linux can use it when it loads.

U-Boot supports creating a bad block table in flash, and has done so since
before 2008.10 (assuming you're not using legacy NAND). Whether it does
this depends on whether the NAND driver requests it with NAND_BBT_CREATE in
nand_bbt_descr.options and NAND_USE_FLASH_BBT in nand_chip.options.

Linux can also create this table. Either way, it only needs to be done
once, not on every boot.

What the patch you quote does, as far as I can tell without what's been
snipped, is allow a new bad block table to be created when erasing the
entire chip. Normally the bad block table would be excluded from a
full-chip erase.

-Scott