[U-Boot] [PATCH 5/9] apf9328: add default board configuration file

[Eric Jarrige]

Dear Wolfgang,

On 24 août 2011, at 07:49, Wolfgang Denk wrote:

> Dear Eric Jarrige,
> 
> In message <D25738A8-8A7A-475A-95F5-8408C6463F4D at armadeus.org> you wrote:
>> 
>>> Stefano is right.  "filesize" and "fileaddr" are dynamic variables,
>>> thet get created and updated on the fly. It makes no sense to
>>> pre-define them to any specific value. [Actually I have some changes
>>> in mind that avoid to save such variables with the environment at
>>> all.]
>> 
>> I understand - It make sense for me to wait for the new interface. 
> 
> Which new interface do you mean?  And why would waiting for it help
> you?

By interface I mean the changes you mentioned to avoid to have "filesize"
and "fileaddr" with the environment variables.


> 
>>> What do you mean by "push U-Boot through the serial port"?  Any of the
>>> respective commands in U-Boot ("loads", "loadb", "loady") will
>>> automatically update the respective variables.
>> 
>> I meant  to boot using the iMX internal bootstrap loader as U-Boot is
>> not
>> yet running. Alternatively I can download U-Boot a second time to have
>> the environment variables initialized. 
>> It is just a longer process than the original one.
> 
> Are you aware of things like "env import" etc.?

That could be the solution. I have to check it.
Thanks for the update.

> 
>>> And what makes you think that 192.168.0.10 might be a free IP address
>>> in my network?  Or assume that 255.255.255.0 is the right netmask in
>>> this network?
>> 
>> http://tools.ietf.org/html/rfc1918#page-4
> 
> This page lists "192.168/16 prefix", i. e. a 255.255.0.0 netmask.
> I know many development environments, and 192.168.x.x is used very,
> very often there. often with a /24 netmask, sometimes differently (at
> DENX we're using it with a /16 netmast, for example).  

"192.168/16 prefix" is only the prefix of the class C private networks.
IMHO that means there are 256 class C networks  (255.255.255.0)  reserved
for private networks as mentioned on the same RFC page by
"..and third block is a set of 256 contiguous class C network numbers"

In the same way, there is another address range 172.16 - 172.31 dedicated class B
private networks for the organization who need /16 netmask.

> 
> And there is absolutely NO guarantee that 192.168.0.10 is free, or
> that multiple users of your boards will boot simultaneously, or ...
> 
> The _concept_ of such a default address is broken.
> 
>>> These addresses may work for you, but they will not work for others,
>>> and thus it makes no sense to use them as defaults.
>> 
>> The armadeus BSP provide a user interface to customize the network
>> parameters according to end user network environment.
> 
> Do you know the amount of efforts needed in any bigger organization
> to set up additional or to change existing network configurations?

I meant our BSP enable to change U-Boot default configuration of the
board to fit the existing networks of the end users/developpers -
not to change the network configuration of any organization. 

> 
>>> Use DHCP?
>> 
>> Sure, DHCP is the best *technical* solution.
>> I meant for static IP address?
> 
> Why does anybody need static IP addresses for the default case, i. e.
> for system bring up?

Well, may be things can be easier to explain with static IP than explaining
how to setup a DHCP server, DNS server....

Anyway we will work more on the DHCP solution if this solution is
acceptable.

Best regards,
Eric