FreeBSD buildkernel process

using GENERIC as example

Stage 0: make directory for building
mkdir /usr/obj/src/sys/GENERIC

Stage 1: configure kernel
config -d /usr/obj/usr/src/sys/GENERIC /usr/src/sys/i386/conf/GENERIC

Stage 2: prepare
cd /usr/obj/usr/src/sys/GENERIC
make KERNEL=kernel cleandir
make KERNEL=kernel obj
build aic7xxx tools

Stage 3: making dependencies
make KERNEL=kernel depend -DNO_MODULES_OBJ
make KERNEL=kernel all -DNO_MODULES_OBJ