A Docker image for cross-compiling Linux kernel for Raspberry Pi and a build script for it.
$ git clone git@github.com:Idein/linux.git --branch rpi-4.9.y-vc4mem
$ git clone git@github.com:Terminus-IMRC/cross-rpi-kernel.git
$ cd linux/
$ ../cross-rpi-kernel/build_kernel.sh -v 2 -t bcm2709_defconfig # Load default config
$ ../cross-rpi-kernel/build_kernel.sh -v 2 # Build and install to dest-rpi2/
$ rsync --rsync-path='sudo rsync' -r dest-rpi2/ pi@remote:/ # Transfer to remote Pi