Grub2
Installation
To install grub to an EFI partition, run
grub-install
Then, run
grub-mkconfig -o /boot/grub/grub.cfg
Changing the fontsize
grub-mkfont -s 10 -o /boot/grub/fonts/myfontname.pf2 /usr/share/fonts/TTF/DejaVuSansMono.ttf
Then, in /etc/default/grub
GRUB_FONT=/usr/share/grub/myfontname.pf2