User:Douglarek/Tutorials/Use systemd-boot

From Gentoo Wiki
Jump to:navigation Jump to:search
Note
Current status of systemd-boot (as of 2024.11.24):
  1. UEFI-only support (likely by design)
  2. ESP discovery limited to one partition; unable to boot other systems installed on different ESP partitions
  3. Fewer dependencies compared to grub, built-in systemd support
  4. For Gentoo, manual kernel entry creation is unnecessary, sys-kernel/installkernel handles this automatically

This guide assumes ESP partition mounted at /efi, systemd as init system, and current grub bootloader. Adjust steps according to specific system configuration. The following steps outline migration from grub to systemd-boot.

Adding systemd-boot Support

Edit /etc/portage/packages.use/installkernel (or appropriate USE file location), remove all grub-related entries, add systemd-boot:

FILE /etc/portage/packages.use/installkernel
sys-apps/systemd boot # Add systemd boot support
sys-kernel/installkernel systemd-boot dracut # Automatic boot entry generation during kernel compilation

Applying USE Flag Changes

root #emerge -avuDU @world

This will recompile systemd and installkernel.

Verifying UEFI Mode

user $ls /sys/firmware/efi/efivars

If the system is in UEFI mode, this command will succeed. If it fails, boot into UEFI mode using a LiveCD and perform the following operations from there.

Installing systemd-boot to ESP Partition

root #bootctl install
Created "/efi/EFI/systemd".
Created "/efi/EFI/BOOT".
Created "/efi/loader".
Created "/efi/loader/entries".
Created "/efi/EFI/Linux".
Copied "/usr/lib/systemd/boot/efi/systemd-bootx64.efi" to "/efi/EFI/systemd/systemd-bootx64.efi".
Copied "/usr/lib/systemd/boot/efi/systemd-bootx64.efi" to "/efi/EFI/BOOT/BOOTX64.EFI".
Random seed file /efi/loader/random-seed successfully written (32 bytes).
Successfully initialized system token in EFI variable with 32 bytes.
Created EFI boot entry "Linux Boot Manager".

Listing Boot Entries

root #bootctl list

If no boot entries are found, proceed to the next step.

Configuring Kernel and Adding Boot Entries

root #emerge -a --config sys-kernel/gentoo-kernel
Note
Use appropriate kernel package. Verify boot entries using bootctl list again.

Configuring Kernel Parameters (Optional)

Edit /etc/kernel/cmdline:

FILE /etc/kernel/cmdline
quiet splash
Note
Changes require regenerating boot entries by above step.

Configuring Boot Options (Optional)

Edit /efi/loader/loader.conf:

FILE /efi/loader/loader.conf
timeout 3

This change takes effect immediately.

Enabling Automatic systemd-boot Updates

root #systemctl enable --now systemd-boot-update.service

Portage hooks can also be used.

Cleaning Up Unused Directories and Dependencies

root #rm -rf /boot/*
root #rm -rf /efi/EFI/gentoo
root #emerge -W grub
root #emerge -ac

The GRUB_PLATFORMS="efi-64" entry in /etc/portage/make.conf can also be removed if present. Reboot to use systemd-boot.

Retrieved from "https://wiki.gentoo.org/index.php?title=User:Douglarek/Tutorials/Use_systemd-boot&oldid=1330532"