tested on ubuntu/focal
look for the latest kernel package
apt search ^linux-image-5.9 apt search ^linux-image-5.8 apt search ^linux-image-5.4
and install the whole set
#kernel.org stable apt install linux-image-5.8.0-31-generic \ linux-headers-5.8.0-31-generic \ linux-modules-5.8.0-31-generic #kernel.org longterm apt install linux-image-5.4.0-54-generic \ linux-headers-5.4.0-54-generic \ linux-modules-5.4.0-54-generic
requirements
apt install libncurses-dev flex bison openssl libssl-dev dkms libelf-dev libudev-dev libpci-dev libiberty-dev autoconf apt install bc screen
cd /usr/src/ screen -S kernel cd linux-VERSION/ cp /boot/config-5.8.0-31-generic .config make olddefconfig make xen.config make > ../dom0.log && echo BUILT make modules_install >/dev/null && echo MODULES INSTALLED mv -f /vmlinuz /vmlinuz.old cp -f arch/x86/boot/bzImage /vmlinuz
https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel
https://help.ubuntu.com/community/Kernel/Compile
https://wiki.ubuntu.com/KernelTeam/GitKernelBuild
https://imil.net/blog/posts/2022/build-a-single-in-tree-linux-kernel-module-debian--clones/