Feedback before making a wiki edit regarding ESP partitions

componentscience · Yesterday 03:19:46

Hello,

Just looking for any feedback regarding a note in the wiki about ESP partition mount points. It appears to be either outdated or in need of clarification if using UKIs. I have successfully installed Arch Linux many times with systemd-boot using only an '/efi' directory and a UKI. Thoughts?

https://wiki.archlinux.org/title/EFI_sy … unt_points

** {{Note|Only [[GRUB]] and [[rEFInd]] support this scheme at the moment.}}

seth · Yesterday 06:30:13

https://wiki.archlinux.org/title/Talk:E … SP_on_/efi

systemd-boot using only an '/efi' directory and a UKI

Technically, https://wiki.archlinux.org/title/Unifie … _from_UEFI

Erus_Iluvatar · Yesterday 10:41:04

I've tried to improve it, you're not the first person to find that part unclear in the last months.

componentscience · Yesterday 12:57:05

The missing clarification was regarding systemd-boot. What are your thoughts on this variation:

"Only the GRUB and rEFInd boot loaders support this scheme at the moment. For systemd-boot, this setup is possible with a Unified kernel image (the kernel is still installed to /boot by pacstrap, but the UKI is installed to the esp partition).}}

Last edited by componentscience (Yesterday 12:59:57)

seth · Yesterday 13:14:03

Yeah, but systemd-boot won't work in its actual capacity as bootloader - if you have *only* UKI(s) why would you install a bootloader itfp?
Your UEFI can boot those directly.

componentscience · Yesterday 16:03:40

How about in the case of running multiple UKIs, multi-boot systems, or A/B style updates, where updates require a new UKI? It has also been said that systemd-boot has functionality to read from separate boot partitions, but I am not familiar with these features.

https://0pointer.net/blog/fitting-every … ether.html

seth · Yesterday 17:51:31

Most systems allow you to select which efi's from

efibootmgr --unicode

to boot.

It has also been said that hat systemd-boot has functionality to read from separate boot partitions

yes: a vfat partition - which is not the /boot directory on your root partition.
The note addresses

The wiki wrote:

mount the ESP to /efi and leave /boot as a directory of the root file system

Feel free to try whether it works, but for all I know/understand systemd-boot cannot boot anything on a non-vfat partition, so if you're placing kernels and initiramfs' into /boot on an ext4 or btrfs partition, they're out of reach.

componentscience · Yesterday 19:25:43

Yes in the system I am describing, the /boot directory is part of the root filesystem, so the kernels inside it are out of reach. They are only used by mkinitcpio when it assembles the UKI. They were placed there by pacman or pacstrap, or by manual entry.

The /efi directory is the esp. It is a separate vfat partition holding the UKIs and other uefi-specific objects. In this setup the UKIs are ideally signed by secure boot, and the other objects are given appropriate permissions. Otherwise they are exposed. Thoughts?

If systemd-boot is also used to read kernels from an additional /boot partition formatted with vfat, it would be assumed that those kernels are customized, or have a valid reason not to be bundled into a UKI? Otherwise they would be redundant?

seth · Yesterday 21:20:34

or have a valid reason not to be bundled into a UKI?

The point is that if you've only UKIs using any kind of bootloader is pointless and it you don't (eg. because you want to boot something that's not even linux, say eg. haiku) the setup w/ /boot on the (non-vfat) root partition for all we know won't work w/ systemd.

Arch Linux

#1 Yesterday 03:19:46

Feedback before making a wiki edit regarding ESP partitions

#2 Yesterday 06:30:13

Re: Feedback before making a wiki edit regarding ESP partitions

#3 Yesterday 10:41:04

Re: Feedback before making a wiki edit regarding ESP partitions

#4 Yesterday 12:57:05

Re: Feedback before making a wiki edit regarding ESP partitions

#5 Yesterday 13:14:03

Re: Feedback before making a wiki edit regarding ESP partitions

#6 Yesterday 16:03:40

Re: Feedback before making a wiki edit regarding ESP partitions

#7 Yesterday 17:51:31

Re: Feedback before making a wiki edit regarding ESP partitions

#8 Yesterday 19:25:43

Re: Feedback before making a wiki edit regarding ESP partitions

#9 Yesterday 21:20:34

Re: Feedback before making a wiki edit regarding ESP partitions

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