[U-Boot] Intent of CONFIG_NAND_ENV_DST?

[Scott Wood <scottwood@freescale.com>]

On 12/19/2011 11:58 AM, Tom Rini wrote:
> Hey all,
> 
> I'm attempting to use CONFIG_NAND_ENV_DST work, and I'm wondering it
> what I see as the intent of the option is the real intent as it's not
> working without patches, but perhaps I'm just using it wrong.  What
> I'm trying to have done is that if the above is set, SPL will read the
> environment from NAND into CONFIG_NAND_ENV_DST (nand_spl/ code does
> this, today) and once U-Boot itself is fired up, env_init will see
> we've been given a real environment and go.  But what happens now is
> that there's no special case of env_relocate_spec that knows our
> current pointer is fine and just needs to populate the table.

Hmm... so it will unnecessarily reread the environment, discarding any
variables that have been modified before then.  That should be fixed (I
think we just need to add CONFIG_NAND_ENV_DST to the ENV_IS_EMBEDDED
ifdef in env_relocate_spec, as was done in env_init), though the primary
intent was simply to get early read access to variables such as serial
baud -- for that, it should already work, right?

-Scott