[U-Boot] [PATCH] km-powerpc: define CONFIG_PRAM to protect PHRAM and PNVRAM

Valentin Longchamp valentin.longchamp at keymile.com
Fri Jul 18 11:10:23 CEST 2014


Hello Wolfgang,

On 07/17/2014 02:47 PM, Wolfgang Denk wrote:
> Dear Valentin,
> 
> In message <1405599840-11984-1-git-send-email-valentin.longchamp at keymile.com> you wrote:
>> When u-boot initializes the RAM (early in boot) it looks for the "pram"
>> env variable to know which is area it cannot use.
>>
>> At this early boot stage, the "pram" env variable is not avaible yet
>> since it gets computed in set_km_env that gets called AFTER the RAM
>> initialization. If the "pram" env variable is not found, the default
>> CONFIG_PRAM value is used.
> 
> Note that I am not objecting against this patch, but I highly
> recommend to fix your board - RAM initialization is actually pretty
> late in the init sequence, and you should have a valid envionment long
> before.
> 

Maybe my commit message is unclear about this. You are right, at the RAM
initialization time, there is a valid environment, and that's the case on our
board too.

However, at the very first boot on a board, the environment is empty (or
unvalid) and the default one is used where this "pram" env variable is not
defined. That's why the CONFIG_PRAM is used in this case and it should be
defined. This is not going to be the case at any later boot if a valid
environment (with pram defined) is found and used.

Best regards,

Valentin



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