Increase Grub2 Resolution in CentOS / Fedora

Quick tip to increase your boot loader resolution in Grub2.

The key is to set GRUB_TERMINAL_OUTPUT to gfxterm and provide some resolution modes appropriate for your monitor in GRUB_GFXMODE parameter.

GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="gfxterm"
GRUB_CMDLINE_LINUX="crashkernel=512m selinux=0"
GRUB_DISABLE_RECOVERY="true"
GRUB_ENABLE_BLSCFG=true
GRUB_GFXMODE=3840x2160,2560x1440,1920x1080x16

Optionally, you can also provide a custom font using

GRUB_FONT=/boot/grub2/unicode.pf2

There are other solutions on the internet suggesting to use vbeinfo or videoinfo.

These solutions do not seem to work for newer systems which boot using EFI