[U-Boot] Initial environment variables

[Ben Warren <biggerbadderben@gmail.com>]

Ron Madrid wrote:
> --- On Thu, 7/16/09, Mike Frysinger <vapier@gentoo.org> wrote:
>
>   
>> the board maintainer decides the default env values, not
>> board users.  Ben's 
>> comment was probably on the assumption that you are in the
>> latter category.
>>     
>
> Ah, that could be why.  Thankfully I am the maintainer for the board.  So I
> am going to assume then that it would be OK for me to add these variable
> settings to my board's include/configs file and submit a patch for it,
> unless I here other objections.
>
> Ron
>   
No, there should be no default net parameters, because you're making 
likely-bogus assumptions about the network that your board's going to go 
into.  Just because your LAN uses '192.168.0.x' doesn't mean anybody 
else's does.  It's even worse for MAC addresses - what if I buy two of 
your boards and plug them into the same switch?  If the addresses are 
identical all sorts of bad things can happen.  Not to mention that 
public MAC addresses are assigned (and paid for) and should be 
guaranteed to be unique.  And private (bit 41 set) addresses are used in 
many different ways.  One systems company that I worked at would program 
these dynamically based on which shelf/slot the board was plugged into.  
It's best to fail loudly (a printf stating that MAC addresses haven't 
been programmed) than to silently cause network issues.  I could go on 
and on, but hopefully you get the point.

regards,
Ben