Requirements for alternative fonts

[Richard Rosner]

Hi,

I recently set up Linux (Debian to be precise) on a new laptop with a
high resolution display. I'd like to increase the font size in Grub
(v2.12) and opted to just use a custom font as the default font "GNU
Unifont Regular" (at least on Debian it is) does have a OTF version, but
seems to look jagged by design, but I'm running into issues. I thought
about just using Noto Mono Regular for it, as Noto is supposed to always
work and a monospaced font seems to be recommended for easier setting of
letters, as Grub uses bitmap fonts. Now my issue is that on one hand,
the conversion to a bitmap font seems to be quite bad, the letters look
really jagged. Also, it seems that despite Noto supposed to being about
no tofu, I actually get a lot of tofu. Both the up and down arrows in
the description text at the bottom of grubs boot selector and the border
around everything is just made up of tofu. Just scaling GNU Unifont
Regular does remove the issue of tofu but the font will always look
jagged no matter what. I tried converting Noto with both grub-customizer
and with grub-mkfont, both with only -s 20 and with -as 20, same result.

So what exactly are the requirements for fonts to be used in Grub so
that they are converted to PFF2 fonts in a higher quality and don't show
tofu? There seems to be a range option in grub-mkfont. Do I need to use
it? And how would I need to define the range? My expectation would be
that grub-mkfont by default would include all symbols needed to display
the default boot menu so I kind of doubt defining a range would be needed.


Best

Richard