Haiku @ Beagle
Another day piss farting about on the PC. Ended up that i was up till 3 last night, so I was a bit tired, and had a nap in the afternoon, and even managed to load up the bin with rubbish from the yard ... but I made some progress, if not much.
So with Haiku I got the booting stuff worked out, loaded it onto an SD card, and tried booting it. Not surprisingly it doesn't get too far. After a lot of playing around I managed to get it far enough that it crashes as soon as it turns on the MMU. The page tables seem to be OK, I think (although it looks to me like it's using old-format tables, and they're not implemented in cortex-a8 afaict - but I tried some variations to no avail), and the other initialisation looks about right ... but as with just about everything i've tried doing on this machine, looking right and being right aren't the same thing.
Might ask about the status on the mailing list, and in the mean-time try some MMU code stand-alone - the load/test cycle is pretty slow going through the old SD card i've been using.