How is the Ethernet MAC address for usb0 defined?

[Dr. H. Nikolaus Schaller]

I am analyzing why the AJZaurusUSB driver creates a new interface on  
MacOS X each time the OpenMoko is rebooted.

No I think I have found that OM does initialize the MAC address of  
the RNDIS/Ethernet gadget driver randomly on each reboot (and MacOS X  
uses that to find devices it already knows). Can anybody confirm that?

If it is so, I would suggest to derive the MAC address from the  
device serial number - or if that is not available - from the  
Bluetooth MAC (but not using the same).

Nikolaus