How to upgrade the Debian 10 kernel from backports without recompiling it from scratch

Question

I'm running Debian 10 on an i9-9900k on a Gigabyte Aorus Pro motherboard (using the integrated Intel graphics chipset) and an nVIDIA RTX 2080Ti graphics card. I have two monitors. I want to have monitor B working with the nVIDIA card and monitor A with the Intel integrated chipset. The problem is that only monitor B is working now. Monitor A is turned off. Maybe there is something bad with the secondary graphic card, because Debian disables the card that's not the most important. I want to enable it. Someone told me that the kernel that I'm using (4.19) is old and it does not support the Intel chipset of the motherboard. I would like to update it, but I don't know how to do that. He said also that it is in the backports. So a couple of lines should be enough. I tried to compile a new kernel from scratch, version 5.3.2, using the default settings, but it didn't work, in fact it freezes during boot. So, my question is: how can I easily upgrade the Debian 10 kernel, from 4.19 at least to a version that allows me to enable the Intel chipset and also firmware-misc-nonfree?

Answer 1

Adapting my Debian 9 answer to Debian 10:

• enable backports:

    echo deb http://deb.debian.org/debian buster-backports main contrib non-free | sudo tee /etc/apt/sources.list.d/buster-backports.list
    sudo apt update
  

• install the backported kernel:

    sudo apt install -t buster-backports linux-image-amd64
  

  (the new kernel will be installed alongside your current kernel, so you can always boot the latter if things go wrong)

• install the firmware:

    sudo apt install -t buster-backports firmware-linux firmware-linux-nonfree
  

As of this writing, this will install version 5.7.10 of the kernel, with the firmware from August 2020.