Bsrgvty

I'd like to change my GRUB's resolution since it seems as if it doesn't use my screen's whole 1920x1080. I tried to get the supported resolutions using videoinfo, but it literally shows nothing. I tried vbeinfo as well, but that didn't work either.

Looking forward to a solution for this or at least a way to tell which resolution GRUB is actually using at the moment.

This is how my GRUB config file looks:

GRUB_TIMEOUT=8
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX="nouveau.modeset=0"
GRUB_GFXMODE=1920x1080

the default look of my grub menu when the some of the content in /etc/default/grub file is

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
#GRUB_GFXMODE=640X480

When i edited the file and changed some of the content in /etc/default/grub like below

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
GRUB_GFXMODE=640X480

and run sudo update-grub it looks like this

when content is like this

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""
GRUB_GFXMODE=960X600

It looks like this after running sudo update-grub

The value 960x600 i choose from below

pratap@i7-6550U:~$ xrandr
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
eDP-1 connected primary 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
 1366x768 60.00*+
 1360x768 59.80 59.96 
 1280x720 60.00 59.99 59.86 59.74 
 1024x768 60.04 60.00 
 960x720 60.00 
 928x696 60.05 
 896x672 60.01 
 1024x576 59.95 59.96 59.90 59.82 
 960x600 59.93 60.00 
 960x540 59.96 59.99 59.63 59.82 
 800x600 60.00 60.32 56.25 
 840x525 60.01 59.88 
 864x486 59.92 59.57 
 800x512 60.17 
 700x525 59.98 
 800x450 59.95 59.82 
 640x512 60.02 
 720x450 59.89 
 700x450 59.96 59.88 
 640x480 60.00 59.94 
 720x405 59.51 58.99 
 684x384 59.88 59.85 
 680x384 59.80 59.96 
 640x400 59.88 59.98 
 576x432 60.06 
 640x360 59.86 59.83 59.84 59.32 
 512x384 60.00 
 512x288 60.00 59.92 
 480x270 59.63 59.82 
 400x300 60.32 56.34 
 432x243 59.92 59.57 
 320x240 60.05 
 360x202 59.51 59.13 
 320x180 59.84 59.32 
HDMI-1 disconnected (normal left inverted right x axis y axis)
pratap@i7-6550U:~$ 

You can use 1920x1080 screen size but you will want to generate a larger font. Although the following GIF uses grub themes for additional graphics, generating larger 24 or 36 point fonts is the same for regular grub.

Make Grub fonts

Even if you are just using regular grub, if you want a different font you must use grub-mkfont program first. The same holds true for Grub Customizer used by OP and Grub Themes used in first section of this answer.

Here are the fonts I have made for grub to use:

$ ll /usr/share/grub/themes/Tuxkiller2/*.pf2
-rwxrwx--- 1 root root 176923 Jun 9 16:41 /usr/share/grub/themes/Tuxkiller2/dejavu_14.pf2*
-rwxrwx--- 1 root root 20041 Jun 9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_bold_17.pf2*
-rwxrwx--- 1 root root 23339 Jun 9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_bold_20.pf2*
-rwxrwx--- 1 root root 31498 Jun 9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_bold_26.pf2*
-rwxrwx--- 1 root root 15244 Jun 9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_regular_12.pf2*
-rwxrwx--- 1 root root 19148 Jun 9 16:41 /usr/share/grub/themes/Tuxkiller2/droidlogo_regular_17.pf2*
-rwxrwx--- 1 root root 113623 Jul 11 17:05 /usr/share/grub/themes/Tuxkiller2/ubuntu_bold_italic_36.pf2*
-rwxrwx--- 1 root root 45391 Jul 11 17:08 /usr/share/grub/themes/Tuxkiller2/ubuntu_light_20.pf2*
-rwxrwx--- 1 root root 41020 Jul 11 17:16 /usr/share/grub/themes/Tuxkiller2/ubuntu_regular_18.pf2*
-rwxrwx--- 1 root root 46423 Jul 11 17:16 /usr/share/grub/themes/Tuxkiller2/ubuntu_regular_20.pf2*
-rwxrwx--- 1 root root 68602 Jul 11 16:59 /usr/share/grub/themes/Tuxkiller2/ubuntu_regular_28.pf2*

To create a font use the grub-mkfont program like this guide outlines: Increase Font in GRUB for High DPI Screens:

sudo grub-mkfont --output=/boot/grub/fonts/DejaVuSansMono24.pf2 
 --size=24 /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf

Then in your /etc/default/grub configuration file tell it to use the new .pf2 font file:

# More readable font on high dpi screen, generated with
# sudo grub-mkfont --output=/boot/grub/fonts/DejaVuSansMono24.pf2 
# --size=24 /usr/share/fonts/truetype/dejavu/DejaVuSansMono.ttf
GRUB_FONT=/boot/grub/fonts/DejaVuSansMono24.pf2

Finally run:

sudo update-grub