bootctl

• systemd-boot (formerly gummiboot) is a EFI boot manager

Partitions

• <esp> is the mount point of the ESP partition
• ESP partition is recommended be mount ESP to /efi

• If using a extended boot loader partition, it's recommended to be mounted at boot

• Warning: if you create a /efi folder, systemd will automatically mount the esp partition into it

• If you want to remove this folder and the auto mount you need to stop the unit efi.automount (you can see it with systemctl list-units --type=automount)

install

• Copies the systemd-boot bootloader into ESP partition
• Creates a EFI boot entry in EFI partition
• /usr/lib/systemd/boot/efi/systemd-bootx64.efi will be copied to:
• <esp>/EFI/systemd/systemd-bootx64.efi and <esp>/EFI/BOOT/BOOTX64.EFI

bootctl install # Locate esp-path at "/efi", "/boot" or "/boot/efi". Locate boot-path (if any) at "/boot"
bootctl --esp-path=/a --boot-path /b install # force path

Auto Probe

• systemd-boot automatically check for windows boot entry at /EFI/Microsoft/Boot/Bootmgfw.efi

Configuration

<esp>/loader/
├── entries
│   ├── arch.conf
├── entries.srel
├── loader.conf
└── random-seed

loader.conf

# <esp>/loader/loader.conf

# the default boot entry
default arch.conf

# time to wait the pick entries screen
timeout 2 # 2 seconds
timeout 0 # no menu is shown and a key (e.g., space) needs to be pressed to show the menu.
timeout menu-hidden # same as above
timeout menu-force # always show without a stopwatch

# resolution of the menu
console-mode 0

# Allows changing kernel parameters on the fly
editor true # enabled by default

# automatically discover boot entries (e.g., windows boot)
auto-entries true # enabled by default

# boot to firmware entry option (firmware may still be reached using "f" key)
auto-firmware true # enabled by default

# Beeped timeout
beep false # disabled by default

entries.srel

• Usually type1

entries

• title: name of the system to be boot
• version: version of the system (when multiple entries with the same title exist)
• efi: efi system to start
• linux: convenience for "efi path"
• options: parameters to be passed to the efi program (or kernel parameters)
• initrd: convenience for "options initrd=path"

# <esp>/loader/entries/arch.conf
title Arch Linux
linux /vmlinuz-linux
initrd /initramfs-linux.img
initrd /intel-ucode.img
options root=PARTUUID=d340b3e6-85af-4d4b-bf60-242614758599 rw # kernel parameters are defined here

• Get the root PARTUUID with blkid