under /usr/src/sys
or /sys

the following dir are related to /sys
--
arch/conf (arch: i386 amd64 ...)

cp GENERIC MYKERNEL
/usr/sbin/config NEW
cd ../compile/NEW
make depend; make # compile kernel (nanoBSD need this, but not make install)
make install # install kernel (note: if only you want to install into VM, nanoBSD does NOT need to do this)