[U-Boot-Users] Ethernet and detecting MAC addresses

[U-Boot-Users] Ethernet and detecting MAC addresses

[Dave Peverley]

AFAICT from the source I'm using (1.0.2) none of the ethernet drivers
bother with detecting their own MAC address (if available) and rather 
rely on hard/soft coded addresses. Is this an intentional by design, or
just something unimplemented as yet? If this is something I can implement
for our board here, does anyone have pointers for where is best to splice 
it in without upsetting anyone? :-) I already have a really untidy rough 
and ready hack that we use internally to do this that works, but I'd like 
to implement properly if possible. 

Best Wishes,

Dave Peverley

---------------------------------------------------------------------------
             Dave Peverley, Software Engineer, MPC Data Limited.
Phone : [+44] (0) 1225 868 228              Web : http://www.mpc-data.co.uk

[U-Boot-Users] Ethernet and detecting MAC addresses

[Wolfgang Denk]

In message <4073E36C.8000901@mpc-data.co.uk> you wrote:
> AFAICT from the source I'm using (1.0.2) none of the ethernet drivers
> bother with detecting their own MAC address (if available) and rather 

Please explain what you mean by ".drivers...their own MAC address".

A driver does not have any MAC address.

Some ethernet devices may have persistent storage for a MAC  address,
but most of them (especially those in embedded processors) don't.

> rely on hard/soft coded addresses. Is this an intentional by design, or
> just something unimplemented as yet? If this is something I can implement

It is intentional and necessary be design, because there simple  _is_
_no_ stored MAC address anywhere around.

> for our board here, does anyone have pointers for where is best to splice 
> it in without upsetting anyone? :-) I already have a really untidy rough 

Read the README, which documents what is beind done now,  and  follow
the  existing  design rules (see section "Note for Redundant Ethernet
Interfaces").


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
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[U-Boot-Users] Ethernet and detecting MAC addresses

[Dave Peverley]

Wolfgang Denk wrote:
>>AFAICT from the source I'm using (1.0.2) none of the ethernet drivers
>>bother with detecting their own MAC address (if available) and rather 
> Please explain what you mean by ".drivers...their own MAC address".
Apologies for the lazy way I posed the question - if you would like 
I will rephrase in a more verbose manner utilising technically correct 
terms, but given that you answered the question I was asking anyway, 
do you really want me to?

> Some ethernet devices may have persistent storage for a MAC  address,
> but most of them (especially those in embedded processors) don't.
Ok, I agree, but the boards I am developing on, do and I would like to 
support it...

> It is intentional and necessary be design, because there simple _is_
> _no_ stored MAC address anywhere around.
At the least I know that all the omap boards (1510 Inn, 1610 Inn, 1610 H2,
and the new one I'm wworking on) all have stored addresses and are supported
by u-boot, hence my question....

> Read the README, which documents what is beind done now,  and  follow
> the  existing  design rules (see section "Note for Redundant Ethernet
> Interfaces").
Thanks, that helps.

Marius Groeger Wrote :
> Actually the smc91111.c driver does something of the sort. See the
> function get_rom_mac(). This is a very simplistic approach and it is
> also invisible to the overall uboot structure. Maybe you can live with
> such an approach?
If thats whats being done for the driver and has been accepted into CVS 
then that sounds like an excellent place to start :-) Thanks!

> Many embedded boards, however, will store their MAC address simply 
> in the global environment, so that's probably the reason why you 
> don't find what you're looking for.
Sure I noticed that hence asking the question. I know its not necessary,
but is a big convenience to not have to individually programme every 
installed boards u-boot with a ficticious unique address when theres one
availiable in ROM....!

Best Wishes,

Dave Peverley

---------------------------------------------------------------------------
             Dave Peverley, Software Engineer, MPC Data Limited.
Phone : [+44] (0) 1225 868 228              Web : http://www.mpc-data.co.uk

[U-Boot-Users] Ethernet and detecting MAC addresses

[Marius Groeger]

On Wed, 7 Apr 2004, Dave Peverley wrote:

> AFAICT from the source I'm using (1.0.2) none of the ethernet drivers
> bother with detecting their own MAC address (if available) and rather
> rely on hard/soft coded addresses. Is this an intentional by design, or

Actually the smc91111.c driver does something of the sort. See the
function get_rom_mac(). This is a very simplistic approach and it is
also invisible to the overall uboot structure. Maybe you can live with
such an approach?

Many embedded boards, however, will store their MAC address simply in
the global environment, so that's probably the reason why you don't
find what you're looking for.

Regards,
Marius

-- 
Marius Groeger <mgroeger@sysgo.com>           Project Manager
SYSGO AG                      Embedded and Real-Time Software
Voice: +49 6136 9948 0                  FAX: +49 6136 9948 10
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