From Fedora Project Wiki

Linux Firmware Minimization

This is a proposed Change for Fedora Linux.
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

Split linux-firmware into more subpackages, and add the ability to automatically install firmware based on the hardware present

Owner

Current status

  • Targeted release: Fedora Linux 37
  • Last updated: 2022-11-23
  • devel thread
  • FESCo issue: <will be assigned by the Wrangler>
  • Tracker bug: <will be assigned by the Wrangler>
  • Release notes tracker: <will be assigned by the Wrangler>

Detailed Description

The linux-firmware RPM is very large (175M src.rpm, 287M *.noarch.rpm per 20211027-126) that bundles most of the system firmware loaded by the kernel, regardless of whether it’s actually needed. Some additional firmwares are already split up into individual subpackages. This change would extend that, splitting out most firmware into appropriate subpackages. The Change would also make the subpackages Supplements the appropriate modalias(...) for the hardware they support and Provides firmware(kmodname/firmwarefile.bin)

Candidates for splitting out:

  • CPU firmwares
  • GPU firmwares
  • Non-Intel wifi firmwares
  • Bluetooth firmwares

Conversely some firmware could probably be grouped together, e.g. have iwlwifi-firmware that pulls in iwl*-firmware (corresponding to openSUSE's kernel-firmware-iwlwifi).

We will also introduce linux-firmware-all that will pull in all subpackages; this will make it easier to manage the firmware packages in different Fedora variants.

A DNF plugin will be written to make use of the Supplements metadata to automatically install the appropriate firmware packages based on the hardware present on the system (see openSUSE's libzypp: https://github.com/openSUSE/libzypp/blob/a34d857dbe3b16d4a7e0219cd213cc5a87966538/zypp/target/modalias/Modalias.cc and https://github.com/openSUSE/libzypp/blob/7f345ea4892fd02345e8de47c2a08ab5b174650b/doc/autoinclude/Modalias.doc)

Feedback

Benefit to Fedora

This would save a lot of disk space on Fedora installations, and make it easier to test individual firmware updates by replacing a single subpackage. It will also bring us into alignment with openSUSE (see their kernel-firmware.spec).

Scope

  • Proposal owners:
    • Create test COPR with proposed changes
    • Add some additional firmware subpackages
    • Add the required metadata (supplements, provides)
    • Write DNF plugin to make use of supplements
    • Write libdnf plugin for PackageKit (and in the future, microdnf)
    • refactor comps for F37
  • Other developers:
    • Validate that installation works with iwl*-firmware replaced by iwlwifi-firmware
    • Test the DNF plugin
    • If it works well, preinstall the DNF plugin and stop installing iwlwifi-firmware or any of the iwl*-firmware
  • Policies and guidelines: N/A (not needed for this Change)
  • Trademark approval: N/A (not needed for this Change)
  • Alignment with Objectives:

Upgrade/compatibility impact

No compatibility impact.


How To Test

  • Enable the test COPR
  • Verify that after upgrading, no firmware subpackages are removed
  • Install the DNF plugin
  • Verify that the DNF plugin works: dnf mark remove a firmware package that is needed, then verify that dnf autoremove does not remove it
  • dnf mark remove all firmware packages, and verify that dnf autoremove only remove the unneeded packages


User Experience

More disk space available, no functional changes.

Dependencies

No dependency, linux-firmware is not required by any package

Contingency Plan

  • Contingency mechanism: (What to do? Who will do it?)
    If the plugin is not ready in time, the other changes would preserve the status quo. So we can postpone shipping the DNF plugin to F38.
  • Contingency deadline:
    Decide on whether to postpone the DNF plugin by beta freeze
  • Blocks release? No


Documentation

Documentation will be added in this HackMD

Release Notes

Retrieved from "https://fedoraproject.org/w/index.php?title=Changes/Linux_Firmware_Minimization&oldid=661561"