> I really hate flag-day syndrome.

I don't think this is a much of a flag day issue if implemented as:

	look for boot.
	if file and loadable, use it
	else
		if directory, change to directory
		look for boot_$machine

One big question is, I suppose, can this be squeezed into the
first-stage bootblocks that don't store block numbers?

The only "flag day" part I can see is if you update the second-stage
boot blocks, removing the old ones, without updating the first-stage.
Possible, certainly (few things aren't ;-), but not too likely.

-allen