[SOLVED] Modified grub and missing bootsplash screen

[pemartins]

I have triple boot in my pc: Kubuntu 18.04, Ubuntu MATE 18.04 and Windows 10. I read somewhere that the last installed OS 'takes over' the grub and the last OS I installed was Kubuntu 18.04 which is my main OS, so no worries all is perfect and no need for changes.

But since a couple of days ago or so I noticed that my boot screen changed and also some parameters changed, like the timeout for loading the default option and the display layout. I also noticed that I cannot control the brightness anymore in Kubuntu 18.04 which means that the option "acpi_backlight=video" I need to add to the grub for it to work is gone.

I rushed to edit the grub but I found no /etc/default/grub file in Kubuntu, which is weird...
Also I checked Ubuntu MATE's grub and it does not seem to be the one being loaded, its options are different of what I'm getting at the boot menu.

Also the bootsplash (bootscreen right?) saying Kubuntu while loading the OS is gone, all I'm getting is the traditional boot log being displayed on the screen.

Any thoughts on what can I do to edit the grub and getting the bootsplash screen back?

[jlittle]

I found no /etc/default/grub file in Kubuntu, which is weird...

I agree, weird. A vanilla version should be in /usr/share/grub/default/grub, is that there? I would also check in /etc/default for a file like "grub.ucf-old", or conceivably a grub.d directory.

If you've got your system is booted, it might be an idea to create a supergrub2 bootable USB; it's only a 20 MB iso.

Otherwise, reinstalling grub might bring it back. Or, in your Ubuntu MATE, you could run sudo grub-install there, to give that install control of the boot.

Running multiple installs like you are occasionally gives grub problems like this; and the result can be the grub rescue prompt "grub>" and nothing works. Some of us use grub on its own partition or btrfs subvolume to stop installs tripping up each other; one has to hand-maintain grub.cfg but in the (not very) long run it saves time and grief and is much simpler.

[pemartins]

@jlittle thank you so much for your help.

Just to check, this is the grub I currently have, is this the vanilla version you mention?

https://i.imgur.com/zBc5jow.jpg

Sorry for putting the image link in code instead of putting the image here but it was too big and somehow distracting.

So indeed I have a grub file at /usr/share/grub/default/grub and most probably that's the one running; also I have the mentioned "grub.ucf-old" file at /etc/default which is certainly my old grub file because it has the mentioned "quiet splash acpi_backlight=video" parameter. Spot on!

Can I just remove the ".ucf-old" extension from "grub.ucf-old" and enter the command sudo update-grub after that? Would that work?

I ain't doing anything until you give me further advise, it's not in my plans tomorrow having to browse for your answer on my mobile phone!

[jlittle]

Just to check, this is the grub I currently have, is this the vanilla version you mention? ...image...

I meant the vanilla version of just the file /etc/default/grub, I wasn't talking about the version of grub. Perhaps a better word would have avoided misunderstanding. Anyway, the image on imgur chops off the picture just before the grub version number.

So indeed I have a grub file at /usr/share/grub/default/grub and most probably that's the one running;

/etc/default/grub is only used by grub-mkconfig, which is called by update-grub. What runs is /boot/grub/grub.cfg.

also I have the mentioned "grub.ucf-old" file at /etc/default which is certainly my old grub file because it has the mentioned "quiet splash acpi_backlight=video" parameter. Spot on!

Can I just remove the ".ucf-old" extension from "grub.ucf-old" and enter the command sudo update-grub after that? Would that work?

Sure. I'd make copies...

$ cd /etc/default
$ cp grub.ucf-old ~
$ sudo cp grub.ucf-old grub
$ sudo update-grub

That file's existence suggests an idea of what went wrong. "ucf" is "Update Configuration File", a debian utility run by APT to handle the case where there's a new version of a file that has user changes in it. It's supposed to ask the user which version to use. It looks like that interaction was interrupted; I wonder if some GUI updater handled it properly.

[pemartins]

Done! Everything is back to how it used to be, also the Kubuntu bootsplash is back.

Just one correction to the information I provided, the renamed grub file was "grub.ucf-dist" and not "grub.ucf-old" as I stated before.
As you recommended I made copies of the file which I'm keeping, we never know if it can be useful in the future.

Thank you very much!