[U-Boot] [RFC PATCH] env: add default env size for CONFIG_ENV_IS_NOWHERE

[Bo Shen <voice.shen@gmail.com>]

Hi Wolfgang Denk,

On 8/11/2013 10:50 PM, Wolfgang Denk wrote:
> Dear Bo Shen,
>
> In message <1376230503-25331-1-git-send-email-voice.shen@gmail.com> you wrote:
>> when CONFIG_ENV_IS_NOWHERE is enabled, it is still need to define
>> CONFIG_ENV_SIZE. So, add a default size (1024 Bytes) to avoid
>> compile error if not define CONFIG_ENV_SIZE
>
> I don;t understand the rationale for this patch.  In which way is the
> environment seize for the CONFIG_ENV_IS_NOWHERE case different from
> any other cases?  For these, we do not define a default either, so why
> should we handle this case differently?

In my opinion, there is a little different. The CONFIG_ENV_IS_NOWHERE 
case only store environment in volatile memory (e.g. DDR SDRAM) while 
not store in non-volatile device.

At first glance of CONFIG_ENV_IS_NOWHERE, I think no need to define the 
CONFIG_ENV_SIZE, actually, it needs to define the CONFIG_ENV_SIZE. So, I 
think add a default value will be better (Maybe another choice to add a 
description in README file to specify how to use CONFIG_ENV_IS_NOWHERE).

> In any cse, the needed environment seize if a pretty board specific
> thing, and I think it makes sense to let the user define it.

Yes, the environment size is a pretty board specific thing. So, in this 
patch, there is an option for user to define it.

> Best regards,
>
> Wolfgang Denk
>

Best Regards,
Bo Shen