Starting multiple domains at boot?

[Jeremy Fitzhardinge <jeremy@goop.org>]

Is there any fundimental reason why we can't support starting multiple
domains at boot?  For example, having something like:

title Xen
        root (hd0,1)
        kernel /xen.gz
        module /vmlinuz-dom0
        module /initrd-dom0.img
	module /some-other-domain
	module /other-domains-initrd.img
	module ...
	module ...


(For simplicity's sake, I'd assume that domains are always (kernel,
initrd) pairs, but one could imagine doing something like content
sniffing or magic module parameters ("xen:kernel", "xen:initrd") to
distinguish the module's roles.)

Has someone already done this?

It seems like it would be a straightforward way to deal with essential
early service domains (like a xenstore domain, for example).

Thanks,
    J