I don't think there is a way to build the single install boot image
(e.g., distrib/i386/floppies/bootfloppy-com) from build.sh or the top
level Makefile.  Do you think having that feature is good?  Has anyone
tried to achieve this?

I guess David Young's CUWiN has similar thing, but its infrastructure
is not compatible with NetBSD's.

Masao