[LinuxBIOS] retrieving MAC from romstrap

[Tom Sylla]

Mailed to soon, xxd does patching directly:
---
Patch the date in the file xxd.1
       % echo '0000029: 3574 68' | xxd -r - xxd.1
       % xxd -s 0x28 -l 12 -c 12 xxd.1
       0000028: 3235 7468 204d 6179 2031 3939  25th May 199
---

On 9/26/07, Ward Vandewege <ward at gnu.org> wrote:
> On Wed, Sep 26, 2007 at 05:02:33PM -0400, Tom Sylla wrote:
> > On 9/26/07, Robert Millan <rmh at aybabtu.com> wrote:
> > >                 unsigned long mac_pos;
> > >                 mac_pos = 0xffffffd0; // refer to romstrap.inc and romstrap.lds
> > >                 mac_l = readl(mac_pos) + nic_index;
> > >                 mac_h = readl(mac_pos + 4);
> > >
> > > and can't understand what is this romstrap and why it retrieves the MAC from
> > > it in runtime.  Is this some kind of legacy interface?  Wouldn't it be simpler
> > > to just hardcode it during build?  E.g. see attached patch.
> >
> > Maybe simpler, but not really correct. What if you have 2 of your
> > boards? With your patch, you have to compile twice. That's not
> > elegant. If you can make just one ROM image, and then automatically
> > change the MAC at a specified location inside of it for each
> > individual motherboard, things work better. (AMI/award/etc do this,
> > when you use their flash utilities, it does not overwrite the MAC so
> > you don't lose it)
> >
> > Your solution is ok if you want to just support your single board on
> > your desktop, but for anybody trying to make a commercial product with
> > LB, they won't want to be recompiling for each unit shipped.
>
> Agreed. MACs are a bit of a pain (also on the MCP55), and we currently do not
> have a good way to deal with them. I have MCP55-based LinuxBIOS machines in
> production that have 00:00:00:00:00:00 as MAC address for each interface, and
> I need to force the MAC manually in /etc/network/interfaces. Not elegant, and
> not ideal. The kernel does not like it either, on startup it says 'complain
> to your bios vendor' ;)
>
> I would like a way to change the MAC address for a rom image with some tool -
> ideally as an option to flashrom, I guess. Keep in mind that there can be
> multiple addresses on a board!
>
> Thanks,
> Ward.
>
> --
> Ward Vandewege <ward at fsf.org>
> Free Software Foundation - Senior System Administrator
>