On Mon, Apr 24, 2023 at 12:15:12PM -0400, Ben Cotton wrote:
https://fedoraproject.org/wiki/Changes/BiggerESP
This document represents a proposed Change. As part of the Changes
process, proposals are publicly announced in order to receive
community feedback. This proposal will only be implemented if approved
by the Fedora Engineering Steering Committee.
== Summary ==
The Fedora installer includes an EFI System Partition of between 200MB
and 600MB by default, of which the lower size is much too small for
firmware updates on modern hardware and also for future bootloader
features like UKI.
This change will increase the minimum size of the ESP to be 500MB,
which is also the same value used by Microsoft for Windows 10 and
newer.
This refers to the minimum size being changed, but later it mentions
the default size being changed. Are the default & minimum sizes
effectively the same in this case ?
nitpick - the github change linked is 512 MiB rather than 500 MB.
== Owner ==
* Name: [[User:rhughes| Richard Hughes]]
* Email: richard(a)hughsie.com
== Detailed Description ==
Modern hardware has UEFI firmware updates that are more than 64MB in
size. The OEMs recommend a ESP free space of double the flash size
plus 20MB and fwupd now enforces this requirement to ensure flash
success. As the ESP is often shared between Windows and Linux, and
also used for firmware updates, and soon to be used by UKIs it's not
enough to just allocate a few hundreds of megabytes. Windows 10 and 11
allocates an ESP of at least 500MiB. Arch also specifies a minimum of
512 MiB.
My only thought is whether 512 MiB is sufficiently future proofed if we
start to make more use of UKIs, given that /boot by comparison is already
at 1 GiB by default IIUC ?
== Feedback ==
There is no alternative -- the ESP has to scale up if we want firmware
updates to continue to work and to support UKIs for next-generation
bootloaders.
== Benefit to Fedora ==
Firmware updates will work on future hardware, and we can boot the
kernel using UKIs using next-generation bootloaders.
== Scope ==
* Proposal owners:
We need to change a number in Anaconda:
https://github.com/rhinstaller/anaconda/pull/4711
== Upgrade/compatibility impact ==
We can't grow the ESP in size, and so this change will only affect new
installs. This is fine, as this will affect new hardware more than old
hardware.
== How To Test ==
Install Fedora and observe that /boot/efi has at least 276MB free
space, even when installed alongside Windows.
== Dependencies ==
Anaconda would need to be modified, and Fedora would have a / or /home
partition that's ~300MB smaller by default than it is now.
For any install which does end up using UKIs on the ESP, the /boot would
no longer need to be as large as it is today as it would not have kernel
images. In fact /boot could potentially not need to exist at all in any
EFI installs using UKIs.
IOW, the increased size for the ESP could potentially be won back by
permitting /boot to be smaller, or eliminating /boot. I'm not suggesting
this needs to be a pre-requisite of this change proposal though, just a
thought for the future. Could be something that is optimized in any cloud
image kickstarts that end up using UKIs.
With regards,
Daniel
--
|:
https://berrange.com -o-
https://www.flickr.com/photos/dberrange :|
|:
https://libvirt.org -o-
https://fstop138.berrange.com :|
|:
https://entangle-photo.org -o-
https://www.instagram.com/dberrange :|