if indeed they're not, we'll have to decide whether we want to go the grub route

if indeed they're not, we'll have to decide whether we want to go the grub route or use NetBSD's own boot menu.

we uh.... sorry, but we don't really like it as a boot menu. it gets the job done, but it isn't our first choice. we care heavily about multiboot and rollback and all that, and those are going to be hard things to shoehorn into it. we also don't like its keybinding choices.