Bug 695666 – sys-kernel/linux-firmware add xz USE flag to compress firmware files

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description Chí-Thanh Christopher Nguyễn 2019-09-26 10:25:18 UTC]

Since kernel 5.3 the firmware loader supports xz compressed firmware files.

Compressing the linux-firmware tree would reduce its size considerably, for linux-firmware-20190923 from 470 MB to 145 MB.

What would need to be done:

* call xz on every firmware file
* Introduce check for CONFIG_FW_LOADER_COMPRESS
* Determine whether CONFIG_INITRAMFS_SOURCE works with compressed firmware files, and if not warn users
* Deal with symlinks in the linux-firmware tree

[Comment 1 Alexander Tsoy 2020-01-07 04:05:15 UTC]

Created attachment 602702 [details]
linux-firmware-20191215.ebuild.patch

My attempt to implement it.

* No check for CONFIG_FW_LOADER_COMPRESS yet.
* Since we are compressing files installed by the package, I thinks using "xz" is not quite appropriate. I've chosen "compress" for now.

(In reply to Chí-Thanh Christopher Nguyễn from comment #0)
> * Determine whether CONFIG_INITRAMFS_SOURCE works with compressed firmware
> files, and if not warn users
I don't understand this part.

[Comment 2 Alexander Tsoy 2020-01-07 04:08:50 UTC]

"-C none" can be used as well. The default is "crc64" which is not supported by the kernel.

[Comment 3 Alexander Tsoy 2020-01-07 04:57:51 UTC]

(In reply to Alexander Tsoy from comment #1)
> (In reply to Chí-Thanh Christopher Nguyễn from comment #0)
> > * Determine whether CONFIG_INITRAMFS_SOURCE works with compressed firmware
> > files, and if not warn users
> I don't understand this part.
Ah, got it. CONFIG_INITRAMFS_SOURCE may contain paths to firmware files.

[Comment 4 Alexander Tsoy 2020-01-07 17:07:49 UTC]

Created attachment 602760 [details]
linux-firmware-20191215.ebuild.patch

* skip compression of the amd-ucode directory. genkernel and dracut cannot read compressed AMD microcode.

[Comment 5 Larry the Git Cow 2022-10-28 17:02:04 UTC]

The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=12113f5d57730f8c36d3df433ec7f1606519e360

commit 12113f5d57730f8c36d3df433ec7f1606519e360
Author:     Sam James <[e-mail]>
AuthorDate: 2022-10-28 16:56:33 +0000
Commit:     Sam James <[e-mail]>
CommitDate: 2022-10-28 17:01:51 +0000

    sys-kernel/linux-firmware: add USE=compress
    
    This compresses installed firmware with xz. Note that
    FW_LOADER_COMPRESS must be enabled in the kernel.
    
    Closes: https://bugs.gentoo.org/695666
    Thanks-to: Alexander Tsoy <[e-mail]>
    Signed-off-by: Sam James <[e-mail]>

 .../linux-firmware-20221012-r1.ebuild              | 374 +++++++++++++++++++++
 .../linux-firmware/linux-firmware-99999999.ebuild  |  34 +-
 sys-kernel/linux-firmware/metadata.xml             |   1 +
 3 files changed, 405 insertions(+), 4 deletions(-)