[U-Boot] [PATCH 1/1] mx51evk: savenv or env save command does not work

[Jason Liu]

2010/11/17 Wolfgang Denk <wd at denx.de>:
> Dear Jason Liu,
>
> In message <AANLkTikB6NYTdz=4cMr_RDuhVXQjTa9zUKaed+vW4C+s at mail.gmail.com> you wrote:
>>
>>  I set it according to the following reason,
>>
>> - Keep the same setting as the original when you commit the mx51
>> support patch. Why you select 128KB? :)
>
> Copying settings without reflecting if they make sense for your own
> system is not really a good idea.

Agree. But I think the original commit for 128KiB env size has been
reviewed on the mail list and no one against it.
So, I keep the same setting. If I change it, some guys main complain
why it change, it will make it
incompatible with the original env setting and make the customer env lost.

>
>> - As I looked through other platform such as OMAP4 for MMC ENV
>> setting, it's also set for 128KB
>
> Ditto.  Please keep in mind that the environment is CRC protected;
> that means the larger the environment area, the more time will be
> needed for the CRC calculation when the system boots.  And quick
> booting is definitely a topic these days, so please reconsider.

OK,

>
>> - Leave much room for the user to store customer env.
>
> Come on.  Do you know how much text can be saved in 128 KiB?  I have
> seen some really kinky environment settings before, where a "printenv"
> would scroll trough thousands of lines (well, hundrets at least) so it
> was next to impossible to find anything, and they needed something
> around 10 KiB or so. 16 KiB is more than enough for 99.9% of the
> users.

We really don't know what data that customer will store. So leave much
room for them is
my first though, But consider the fast boot, what you said make sense.

>
>> > Can we save some time by saving or reading the environment reducing its
>> > size ? Or do you plan to save something more in this area ?
>>
>> It's always the trade-off, set to 512B or less will save some time
>> according to 128KB, but it will face much risk to change the code
>> frequently to meet the increasing env size requirement.
>> what's the size do you think is suitable?
>
> 16 KiB.

OK,  do you think we need change all the platform to reflect the 16K
env size for MMC case?

>
> Best regards,
>
> Wolfgang Denk
>
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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> ago."                                              - Bernard Berenson
>