cp /usr/src/linux/arch/i386/boot/zImage /dev/fd0
that hasn't worked for me since sometime around 1.3.60. The command
from the arch/i386/boot Makefile does work, I recommend putting it in
the README instead (or figure out why the plain cp doesn't work)
dd bs=8192 if=/usr/src/linux/arch/i386/boot/zImage of=/dev/fd0