On Thu, Feb 14, 2008 at 1:36 PM, Edward Jubenville edjubenville@adelphia.net wrote:
If you are designing your own board in relatively low quantities, you might want to look at Maxim chip DS2502-E48. It holds a guaranteed unique Ethernet MAC address, and would save you the hassle and cost of registering to get your own address block. The chip uses the Dallas/Maxim 1-wire interface which I don't think u-boot supports (at least, not at the time), so I wrote a u-boot standalone bit-bang program to print the MAC address, and I manually set ethaddr in the u-boot environment.
We have code in our local tree (a bit hackish) to talk to this part and use it to grab the MAC address. I think someone else posted something similar to the mailing list a while back. We have since switched to using our own block of MAC addresses serialized into flash during production. If someone wants it to play with and polish up, let me know.
As for the EEPROMs, a lot of the ugliness can be traced to the two and three wire busses used to talk to most of them (there used to be parallel EEPROM, dunno anymore). I believe the EEPROM cells inside that actually store bits are perfectly reliable. If there was a good way of making the write 'atomic' you could make allowances for the system level issues.