Change screen resolution in login screen and text console

Question

I know I can change the screen resolution for:

1. Desktop (I know I can change it using Settings > Display or xrandr)
2. Grub (I know I can change it in /etc/default/grub GRUB_GFXLOAD variable)

But, how to change the screen resolution for:

3. Login screen of lightdm
4. Login screen and console (tty1, tty2, ...)? (i.e. Alt+Ctrl+1)

?

I am using Intel HD graphics (ubuntu 14.04 LTS/lightdm) with a screen up to 3840x2160 but I just want to stuck with 1920x1080....

Answer 1

Thank you, you got me almost all the way there with your line:

video=eDP-1:1920x1080

However it took me a while to figure that eDP-1 was your monitor. You can see all the potential monitors in /sys/class/drm/

This one-liner, will show you what's connected:

for p in /sys/class/drm/*/status; do con=${p%/status}; echo -n "${con#*/card?-}: "; cat $p; done

In my case, the 4k panel was on DVI-D-1 and I no longer have eyestrain, so thanks again, Andy

Answer 2

After a study, I figured it out that the system switch the video from grub (GRUB_GFXLOAD) -> kernel (GRUB_GFXPAYLOAD_LINUX) -> drm (?) -> xserver (xrandr/xorg.conf/lightdm.conf)

For drm part, it is set using video= kernel command line. I solved my problem by adding

video=eDP-1:1920x1080 

in kernel command line.