Bootloader

systemd-boot is the ultimate bootloader for Linux. It boots your system, and nothing else.

Note

This only works for [[Partition the Drive#Check for UEFI]|UEFI Systems]]

Install the Bootloader §

Ideally, bootctl should be able to automatically detect your EFI partition.

bootctl install

If it doesn’t find it, then you can use cfdisk.

1. Open your drive with cfdisk
2. Select the drive that you want to be your EFI system partition
3. Select [ Type ]
4. Select EFI System
5. Select [ Write ], and type yes
6. Select [ Quit ]

If all else fails, you can use --esp-path=/efi to force it to install to the right location.

Unified Kernel Image §

While systemd-boot technically supports loading an initrd, I still perfer to use a Unified Kernel Image. systemd-boot has first class suport for UKIs and will detect them automatically.

We’ll build our UKI with mkinitcpio.

Kernel Command Line §

Normally, you would put your kernel command line in your GRUB_CMDLINE..., but you don’t have that anymore. mkinitcpio looks for kernel cmdline files in /etc/cmdline.d/*

It is required to specify a root parameter, at least. For example, if you are using labels and btrfs, this might be your cmdline.

## /etc/cmdline.d/root.conf
 
root=LABEL=root rootflags=subvol=@ rw rootfstype=btrfs

Preset File §

mkinitcio uses two files to build your initramfs. /etc/mkinitcpio.conf, and /etc/mkinitcpio.d/linux.preset. We’ll edit the latter one to tell mkinitcpio to bundle the microcode, kernel, and initramfs into a unified kernel image.

# mkinitcpio preset file for the 'linux' package
 
- ALL_config="/etc/mkinitcpio.conf"
ALL_kver="/boot/vmlinuz-linux"
ALL_microcode=(/boot/*-ucode.img)
 
PRESETS=('default', 'fallback')
 
- default_config="/etc/mkinitcpio.conf"
- default_image="/boot/initramfs-linux.img"
+ default_uki="/efi/EFI/Linux/arch-linux.efi"
+ default_options="--splash /usr/share/systemd/bootctl/splash-arch.bmp"
 
- fallback_config="/etc/mkinitcpio.conf"
- fallback_image="/boot/initramfs-linux-fallback.img"
+ fallback_uki="/efi/EFI/Linux/arch-linux-fallback.efi"
+ fallback_options="-S autodetect"

Be sure to replace /efi with where your EFI system partition is mounted.

Installing §

Actually, systemd-bootautomatically looks for Unified Kernel Images in /efi/EFI/Linux, so we don’t have to do anything to install it.

Extension §

https://www.reddit.com/r/archlinux/comments/qy281v/boot_an_archlinux_iso_directly_from_my_boot_using/