Arch Linux

Roark

Member

Registered: 2023-11-30

Posts: 7

Using Plymouth with UKI/Secure Boot

Hey there. I did a new Arch install yesterday. The install was straightforward and things are up and running smoothly; it's not my first Arch install as I ran it as my daily driver during college. I have a post-install question that I'm hoping to get some assistance with. Bear in mind this is pretty nitpicky/niche so even if it goes unresolved it's not going to affect me at all, but it is something I'd like to get sorted out if possible.

For full(-ish) context, my setup is configured as follows:

• 1TB NVMe SSD partitioned into three partitions. Partition 1 is a 512MiB EFI partition, partition 3 is a 64GiB encrypted swap partition, and partition 2 is an encrypted BTRFS partition that fills the rest of the space.

• Using mkinitcpio to generate kernel images.

• Other hardware is AMD 5800X3D CPU, AMD 7900XTX GPU, 64GiB memory if that matters at all.

• I'm running KDE Plasma/Wayland.

• I attempted to use a signed UKI for Secure Boot essentially following this write-up, but am now just using a generic kernel (more info in the question below).

My question is about using Plymouth with a signed UKI. I kind of like having a Plymouth splash when booting. Is it possible to do this using a UKI? I know I can trivially set up the Arch Linux bmp as a static splash image, but it'd be neat to have Plymouth working. I imagine this might involve needing to move the required Plymouth stuff onto the EFI partition.. but I'm not certain about that. This is where I'm super ignorant and couldn't find a straightforward answer anywhere. Since switching to a generic kernel I've tried to set up Plymouth as well by adding plymouth to the HOOKS section of my linux.preset file and then running "mkinitcpio -P" to regenerate everything. It doesn't seem to show Plymouth at all either before (expected) or after decrypting the BTRFS partition. I've seen mentions of having this setup work for others, but I cannot seem to get it working myself.

Any help is appreciated!

Last edited by Roark (2023-11-30 20:41:35)

Barrigers

Member

Registered: Yesterday

Posts: 1

Re: Using Plymouth with UKI/Secure Boot

Maybe a late response, but for anyone wondering how to use Plymouth with UKI, you should look at where your Kernel parameters come from, when using UKI they generally come from "/etc/kernel/cmdline" so you should append to the same line

splash

for enabling plymouth splash, and probably you will also want:

quiet loglevel=3 vt.global_cursor_default=0

for quiet boot, register errors to a log file and disabling the blinking cursor, respectively. And if you also want to disable the default boot splash that comes when you use "archinstall" with UKI, you should edit the file "/etc/mkinitcpio.d/linux.preset", and remove from "default_uki" this text:

--splash=/usr/share/systemd/bootctl/splash-arch.bmp

Now just run

sudo mkinitcpio -P