====== * This guide applies only to Ubuntu 20.04 images using kernel 5.4 already *

Download and build the kernel source

Updating Kernel and DTB (Device Tree Blob)

Please note that native kernel compile on ODROID-XU4 will take about 25 minutes.

$ git clone --depth 1 https://github.com/hardkernel/linux -b odroid-5.4.y
$ cd linux
$ make odroidxu4_defconfig
$ make -j8
$ sudo make modules_install
$ sudo cp -f arch/arm/boot/zImage /media/boot
$ sudo cp -f arch/arm/boot/dts/exynos5422-odroid*dtb /media/boot
$ sudo cp -f arch/arm/boot/dts/overlays/*.dtbo /media/boot/overlays
$ sync

Updating root ramdisk (Optional)

$ sudo cp .config /boot/config-`make kernelrelease`
$ sudo update-initramfs -c -k `make kernelrelease`
$ sudo mkimage -A arm -O linux -T ramdisk -C none -a 0 -e 0 -n uInitrd -d /boot/initrd.img-`make kernelrelease` /boot/uInitrd-`make kernelrelease`
$ sudo cp /boot/uInitrd-`make kernelrelease` /media/boot/uInitrd
$ sync

Probably need to install some dependent packages if you meet any error while kernel building

sudo apt install flex bc libssl-dev bison