I'm dual-booting Fedora on a Mac.

Due to driver issues, I prefer to use modified "t2" kernels.

Grub 2 only shows a tiny, faint, white-on-black menu for a moment, before selecting the default kernel. It's not long enough for me to read the list and find the right kernel and pick it.

Grubby let me change the default, but that doesn't keep up with updates.

How can I improve readability in the grub 2 menu? I understand one solution involves finding and installing themes, presumably from here https://github.com/vinceliuice/grub2-themes, although the documentation site is down, and another involves installing fonts in /boot/grub2/fonts and adding a line to /etc/default/grub

How can I increase time allowed in the grub 2 menu? Do I just open /etc/default/grub and change GRUB_TIMEOUT=5 to =30?

Should I undo the grubby changes, and if so, how? man grubby doesn't say anything about this. Searching for revert grubby or default grubby mostly turns up instructions on how to use grubby to revert to an old kernel as the default, if a new kernel causes trouble.

For now I've updated the grubby default.

Yes, and after saving the change run as root/sudo: grub-mkconfig -o /boot/grub2/grub.cfg

If you simply hit the down arrow when you first see the menu you should be able to choose other entries, if there are any.

The link below discusses this, firstly changing the GFXMODE entry in /etc/default/grub. More suggestions further down the page at the link below.

https://unix.stackexchange.com/quest...-be-customised

I lost my reply, but this isn't working out.

I am trying to 1. increase the font sizes so they aren't so hard for me to read, and 2. update the defaults.

I've had serious trouble after tweaking screen settings, so am not going to try that here. I tried to copy Roboto Slab Regular to my downloads folder, and run sudo grub2-mkfont -s 30 -o /boot/grub2/RobotoSlabRegular30.ttf /home/[username]/Desktop/RobotoSlab-Regular.ttf but get "sudo grub2-mkfont -s 30 -o /boot/grub2/RobotoSlabRegular30.ttf /home/marjaerwin/Desktop/RobotoSlab-Regular.ttf
" and am left with the default barely-readable fonts.

And I've had a lot of trouble setting the current default using grubby and xed + mkconfig. Maybe it's finally working, maybe not.

You don't indicate whether you edited the /etc/default/grub file and ran grub2-mkconfig after that change.

IME, Grub2 by default, unthemed, uses either very large fonts, or fonts that at least are larger than typical of Grub themes. If grub2-breeze-theme is installed, I'd start troubleshooting by uninstalling it. Another /etc/default/grub change would be to switch between console and gfxterm for GRUB_TERMINAL=.

I had a more detailed post, but lost it while rebooting. I did all that, it isn't working. I have *repeatedly* tried:

sudo grubby --set-default /boot/vmlinuz-6.8.10-300.t2.fc40.x86_64

It defaults to 6.8.9.

sudo grubby --info=ALL

6.8.10 is 1 in the list

sudo xed '/etc/default/grub'

GRUB_DEFAULT=1 to match the list

sudo xed '/etc/default/grub'

I get a message about "generating grub configuration file ..." but it still defaults to 6.8.9 the next time around.

dnf list installed, checking under grub

grub2-common.noarch 1:2.06-121.fc40 @updates
grub2-efi-ia32.x86_64 1:2.06-121.fc40 @updates
grub2-efi-ia32-cdboot.x86_64 1:2.06-121.fc40 @updates
grub2-efi-x64.x86_64 1:2.06-121.fc40 @updates
grub2-efi-x64-cdboot.x86_64 1:2.06-121.fc40 @updates
grub2-pc.x86_64 1:2.06-121.fc40 @updates
grub2-pc-modules.noarch 1:2.06-121.fc40 @updates
grub2-tools.x86_64 1:2.06-121.fc40 @updates
grub2-tools-efi.x86_64 1:2.06-121.fc40 @updates
grub2-tools-extra.x86_64 1:2.06-121.fc40 @updates
grub2-tools-minimal.x86_64 1:2.06-121.fc40 @updates
grubby.x86_64 8.40-75.fc40 @fedora

No sign of any grub2 themes

Using

sudo xed '/etc/default/grub'

switching to gfxterm

sudo grub2-mkconfig -o /boot/grub2/grub.cfg

does switch from console, which was barely readable with too much eye strain, to gfxterm, which is completely unreadable.

I think I was misreading sudo grubby --info=ALL and should use the index number *before* each entry, instead of the one *after* it. But I would still like more-readable text in grub2, regardless.

FWIW, it would not surprise me, absent a custom theme, that this could be a problem without a solution. I have an iMac 2007, so not HiDPI, 24" 1920x1200. I have two openSUSE Grubs doing boot menu, and like most things on a Mac, fonts are small. When the older release's Grub shows up, it's a little plain text thing using only maybe a 14cm wide portion of the screen center, so I can imagine on a HiDPI screen it would be itty bitty scribble. When the newer Grub shows up, it's obviously using a theme, a much greater portion of the screen, and the fonts are not quite so little. Fedora does offer a package named grub-customizer. Have you thought to try it?