Step-by-step – Kernel 5.13 From Source Ubuntu 21.04 Installation

Installing

7. 7. Installing Kernel

   Finally, to Install Ubuntu Linux Custom Kernel
   Simply play:

   sudo dpkg -i ../linux-image*custom_*.deb ../linux-headers*.deb

   And this setup includes also the Custom Kernel Headers that you don’t will find online…
   And finally reboot with:

   sudo reboot

   Finally, you should boot into your barely new Ubuntu Linux Kernel :)
   To check it run:

   uname -r

   In case of Issues you still can choose the previous one on the GRUB Splash Screen.

   

8. 8. Updating Firmware

   How to Update Linux Devices Firmware on GNU/Linux

   Updating Firmware Guide

   How to Install Linux Git Firmware on GNU/Linux

   This step may be required to make use of some New Device Drivers if the built Kernel is above that in System provided by Distro.