This is obviously causes me a problem with automated installs started
via PXE boot as the installed cannot DHCP as the MAC address is wrong.
The obvious fix for this is to try and read the MAC address from the
canonical location... ie where is the source of the address writen
into the controlers registers at power on? But do we know where that
may be?
The other solution would be unconditionally reset the controler to
it's power on state then use the current logic? can we reset the
controller via software?
There does seem to be an nv_mac_reset function... and this does seem
to be called if the card has a capability DEV_HAS_POWER_CONTROL but it
is called in nv_open() while the MAC is read in nv_probe().