[U-Boot] [PATCH v1 1/3] Make mmc init come before env_relocate

[Scott Wood]

On Tue, Sep 22, 2009 at 08:57:33PM +0200, Wolfgang Denk wrote:
> I'm biased. I understand that you do this because you need it for the
> next patch, which reads the environment from MMC card. But then MMC is
> just one out of many storage devices, and with the same right we would
> have to move the SCSI or DoC or S-ATA initialization up, because we
> could implement storing the environment on such devices, too.
> 
> This has not been done so far, because it suffers from the fundamental
> problem your code is suffering from, too: you cannot access the
> environment early enough, so for example your board boots with a
> hard-wird, unchangable console baud rate, despite that you suggest to
> the user he could change it.
> 
> I don't like that, and therefore tend to NAK the whole approach.

The same applies to NAND.  The CONFIG_NAND_ENV_DST mechanism makes it a
bit better (the first stage loader puts the environment in a designated
part of RAM); perhaps something similar could be done here?

There's still a problem with doing any console output during the first
stage loading itself (such as to indicate failures).  For that, the best
I can think of would be to have a CONFIG option for a hardcoded baud, and
if you leave it undefined you will get no output until the second stage.

-Scott