Continue Without Boot Loader
This option can be used to complete the installation even when no boot
loader is to be installed, either because the arch/subarch doesn't
provide one, or because none is desired (e.g. you will use existing
boot loader). This option is especially useful for
Macintosh, Atari, and Amiga systems, where the original operating system
must be maintained on the box and used to boot GNU/Linux.