Just FYI (maybe :-) ), BSD/OS handles this by using the packed
locators only as starting points for the "real" locators passed
to the driver at autoconfig time.  The real locators are made up
by overriding the compiled-in ones with the ones from commands
fed to /boot, either directly at the keyboard, or via /etc/boot.default.
(Of course, with no override, the compiled-in one passes through.)

(It turns out that, even if everyone *has* source, a lot of people
do not want to compile a new kernel -- they would rather stuff a
set of commands into boot.default.)

Chris