[U-Boot] RE : Davinci DM365 custom design : Problem when reading uBoot environment variables

Reda MIMOUNE reda.mimoune at easii-ic.com
Thu Sep 16 09:42:07 CEST 2010


Hi Scott.
Thank you for your answer.

>You can use CONFIG_ENV_RANGE to declare a multi-block range, larger than
>the environment size, to allow bad blocks to be skipped.

>You need to use CONFIG_ENV_RANGE and keep the environment the same size
>-- otherwise it thinks you really want two blocks of environment data,
>and one of those blocks being bad is still fatal.

Thank your for the info. I will put this flag in my board definition file. I is exactly the case.
The block I choose to be the environment block became bad so i increased the size to 2 blocks
and the second block became bad.
So in my both cases, what you said explains that the case I met. I will put this flag and check if it
is present in my 1.3.4 version.

>Or you can use the new env.oob feature to dynamically mark a known-good block as
>your environment.

I do not know this feature. To which config flag does it relate ?

>Please be careful with that.  Unless you have reason to believe that
>the block was accidentally marked bad by something software did, you
>ought to leave bad block markers in place. 

That's what I believed since they became bad only after uboot wrote to them...

>The manufacturer put that marker there to indicate that the block is unreliable (it's normal for
>NAND flash to contain a few such blocks).

For this i am ok with you.

Another question or confirmation: when using environment in NAND, must the environment size be the same than the
NAND block size, i.e 128KB in my case (which i think is too huge) ?

Thank you for answering

Reda



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