Wait... What??? Where are all my /boot files gone?

Hello future me 👋

You might wonder where all the files e.g. /boot/vmlinuz-linux, /boot/amd-ucode.img, /boot/initramfs-linux.img and the boot loader configs in /boot/loader/entries are gone.

I changed everything to Unified kernel images, by primarily changing the file /etc/mkinitcpio.d/linux.preset to generate the UKI. I also told the generation of /boot/vmlinuz-linux to be placed in /usr/local/share/boot/vmlinuz-linux instead, by setting ALL_kver="/usr/local/share/boot/vmlinuz-linux". The newly generated files will end up in /boot/EFI/Linux/arch-linux.efi and /boot/EFI/Linux/arch-linux-fallback.efi. systemd-boot will pick up these automatically. So no further entries are needed. Since, there are no boot loader entries any more, we must tell the system somehow about our cmdline. This is done in /etc/cmdline.d/*.conf. This files are respected by mkinitcpio and are bundled into the mentioned /boot/EFI/Linux/arch-linux*.efi files.

$ cat /etc/cmdline/10-root.conf
rd.luks.name=9c8381f8-7e0f-44f6-be26-655b70d33a32=root root=UUID=a1af7e43-857b-4903-8896-e25484175e5d

$ cat /etc/mkinitcpio.d/linux.preset
ALL_kver="/usr/local/share/boot/vmlinuz-linux"

PRESETS=('default' 'fallback')

default_uki="/boot/EFI/Linux/arch-linux.efi"
default_options="--splash /usr/share/systemd/bootctl/splash-arch.bmp"

fallback_uki="/boot/EFI/Linux/arch-linux-fallback.efi"
fallback_options="-S autodetect"

While I was there, I decided to get rid of /boot/amd-ucode.img as well. mkinitcpio collects the firmware from /usr/lib/firmware/amd-ucore/ anyways, and packs it into the initramfs. No need to keep the file around. However, /boot/amd-ucode.img is part of the package amd-ucode. I had to tell pacman to don’t extract those files.

$ grep NoExtract /etc/pacman.conf
NoExtract   = boot/*-ucode.img

Those changes do provide nothing but a learning opportunity 😄 And maybe… just maybe… in some point in the future, I will sign everything.