systemd also comes with a bootloader aptly named =systemd-boot= though it only supports UEFI-based firmware.
Just like GRUB, they can be configured through plain-text files.
For detailed information about the bootloader, see the manual page =systemd-boot.7=.
With a complete installation, the bootloader config folder may look like the following list.
#+begin_src
/boot/
`-- loader
|-- entries # (ref:loader-entries)
| `-- arch.conf
|-- loader.conf # (ref:loader-conf)
`-- random-seed
#+end_src
- [[(loader-entries)][=loader/entries/=]] is a directory containing all of the entries available to be booted.
- [[(loader-conf)][=loader.conf=]] contains the loader configuration.
Most Linux distros with systemd installed should have a sample config file somewhere. [fn:: In case of Arch Linux, it has an example file at =/usr/share/systemd/bootctl/=.]
As an example, we'll show what those look like.
=loader.conf= is the configuration for the boot loader including the timeout seconds among others.
Here is a sample of a bootloader configuration.
#+begin_src
default arch
timeout 4
#+end_src
In this config, this simply makes the =arch= loader entry to be default when no actions has occurred.
It will start loading it automatically after a timeout of 4 seconds.
The =arch= loader entry can be found at =${ESP}/loader/entries/arch.conf=.
The following code block shows what a loader entry looks like.
#+begin_src
title Arch Linux
linux /vmlinuz-linux
initrd /initramfs-linux.img
options root="PARTUUID=${PARTUUID}"
#+end_src
You can customize and create extra entries for the same installation.
This is what [[id:7e8e83d5-4b08-44f6-800d-a322f6960a62][NixOS]] does with its system generations, letting the user to boot to a specific point in time from the boot loader.
