To probe disks on the system for other operating systems:
# os-probe
Search the new kernel images and update the grub configuration
# update-grub
But in fact, kernel make install will automatically run update-grub..
# cd LINUX_SOURCE_TREE
# cp /boot/config-`uname -r` .config
# make menuconfig
# make -j4
# make modules
# make modules_install
# make install
Reboot! (Don't blame me if your machine doesn't boot!)
