Re: RFC: Platform data for onboard USB assets

Andy Green
2011-03-18T10:09:59Z

On 03/18/2011 09:55 AM, Somebody in the thread at some point said:

>>> So how does the Host LAN driver know what MAC address it should use?
>>
>> This is the problem we're trying to work out. The EEPROM is not
>> present, and user space has no way of knowing which MAC address
>> to set to which device. Note that there might be multiple
>> USB devices of the same type that are indistinguishable to user
>> space, so setting the MAC address there would not be completely
>> safe.
>>
>
> And what happens if you need to use u-boot or some bootloader with
> ethernet network support?
>
> Wouldn't it be better to have the MAC address programmed at the
> bootloader level?

Generally trying to have stuff half done in bootloader and half in Linux
makes things fragile and makes another place for trouble to hide (in
addition to bootloader state such as U-Boot env or boot.scr or
what-have-you needing distro control for updates).

If your bootloader is bloated enough to target network operations under
its own steam, it's bloated enough to set a random MAC or use the same
CPU ID scheme. But it doesn't mean that Linux should not assert the
state it wants when it runs.

-Andy