How does /etc/default/console-setup work?

Solution 1:

setupcon is the program which is responsible for updating /etc/console-setup/cached.kmap.gz. setupcon is run on startup inside the initramfs image, so you'll need to update that before the changes apply

Solution 2:

The program setupcon uses the /etc/default/console-setup file. Setupcon has a man page that refers to a README file. The README file is /usr/share/doc/console-setup/README.gz. That file indicates that you need to invoke setupcon as part of the boot sequence to have the console parameters changed automatically.

Edit the /etc/default/console-setup file to suit your needs. You can verify that the settings do what you want by opening a terminal ctrl-alt-f1, logging in and running setupcon.

To make the changes happen automatically with each reboot, edit the file /etc/rc.local to add the line setupcon above the exit 0 line.

Both files, /etc/default/console-setup and /etc/rc.local require root privileges to edit.