```bash
sudo apt-get install gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabihf-

make exynos_defconfig
make menuconfig ( i need to enable some modules to make the the usb keyboard work)
make -j5 zImage modules dtbs
make modules_install ARCH=arm INSTALL_MOD_PATH=../modules

cat arch/arm/boot/zImage arch/arm/boot/dts/exynos4412-odroidu3.dtb > zImage_dtb
```

On device
```bash
$ sudo update-initramfs -c -k ${kver}
$ sudo mkimage -A arm -O linux -T ramdisk -a 0x0 -e 0x0 -n initrd.img-${kver} -d initrd.img-${kver} uInitrd-${kver}
$ sudo cp uInitrd-${kver} /media/boot/uInitrd
```