grub-mkconfig

• Grub config is defined via /etc/default/grub saved to /boot/grub/grub.cfg

# Generate grub config from /etc/default/grub
grub-mkconfig -o "/boot/grub/grub.cfg"

Kernel Parameters

• Check the parameters your system was booted up with at /proc/cmdline

Temporary parameters

• Press e when the menu shows up and add them on the linux line

linux /boot/vmlinuz-linux root=UUID=0a3407de-014b-458b-b5c1-848e92a327a3 rw loglevel=3 quiet splash video=1920x1080

• Press ctrl + x to boot with these parameters.

Permanent parameters

• To make the change persistent after reboot, edit /etc/default/grub and append your kernel options between the quotes in the GRUB_CMDLINE_LINUX_DEFAULT line

GRUB_DEFAULT="0" # index to boot (from the entry list in /boot/grub/grub.cfg)
GRUB_TIMEOUT="2" # timeout in seconds
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" # kernel parameters
GRUB_DISABLE_OS_PROBER=false # detect other OS's

• And then re-generate the grub.cfg