raspberry pi cross compile kernel

Cross compile platform: Ubuntu x64
Target: Raspberry pi

1. Download tool chain and configuration

• Get from git

git clone https://github.com/raspberrypi/tools.git

• Add tool chain gcc path to /etc/profile, it will take effect when next login.

PATH="$PATH:/usr/local/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin" >> /etc/profile

2. Download kernel source
git clone https://github.com/raspberrypi/linux.git
  
3. Get raspberry pi config

• Login to raspberry pi console and:

zcat /proc/config.gz > .config

• Back to download source code location
• Copy config file 

scp pi@:~/.config .
4. Make kernel and module0

• Make config

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- oldconfig

• kernel compile

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-

• module install

mkdir ../modules
make modules_install ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=../modules/

•  Generate image

cd ~/tools/mkimage
./imagetool-uncompressed.py ~/linux/arch/arm/boot/zImage"

5. Copy image and modules to pi
scp ~/tools/mkimage/kernel.img pi@:~/
scp -r ~/modules ~/ pi@:~/

6. Login pi console and move image and modules to system boot path

• Backup original kernel if needed

mv /boot/kernel.img /boot/kernel.img.bak

• Move new kernel image to boot partition

mv kernel.img /boot/kernel.img

• Move corresponding modules to lib

mv modules/lib/modules/3.18.x /lib/modules/

7. Reboot pi and check the it uses new kernel
uname -r