Changes
added feedback using mbootpack without an initrd
:It may depend on the "mkinitrd" you have - almost all distributions ship with a different mkinitrd script, which may have different options.
::In my case (Slackware 13, linux 3.2.9, xen 4.1.2, mbootpack 0.6) i used the mbootpack '''without''' any initrd and it worked just fine.