When they're new probably not yet. But Tyan has a good record of support in coreboot. So it might just be a matter of time.
And coreboot on a server makes sense.
What I wondered before and now also is: Why XGI chips? Everybody knows that these chips suck in Linux. Yes, a week ago after years of silence something happened and yes on server boards you probably don't need 3d and much 2d accel from an onboard chip but ... *sigh* I don't understand why they put the XGIs on it.
Stop TCPA, stupid software patents and corrupt politicians!