gamescope's built-in PipeWire node has always been SDR-only: it offers BGRx
and NV12, and `paint_pipewire()` hardcodes a Gamma-2.2 composite with the SDR
screenshot LUT set. So an HDR game reaches punktfunk already tone-mapped down,
and the whole gamescope backend streams 8-bit no matter what the client can
decode. Games CAN render HDR on a headless gamescope today — only the capture
half is missing.
Carry the two patches that close it (packaging/gamescope/patches): the node
additionally offers `xRGB_210LE`/`xBGR_210LE` with MANDATORY SMPTE ST.2084 +
BT.2020 props, mapped to the same 10-bit capture texture the HDR AVIF
screenshot path already allocates, and `paint_pipewire()` composites into them
with the HDR screenshot LUTs + `EOTF_PQ` — which is exactly the in-tree
`bHDRScreenshot` branch. The new formats are listed LAST, so every existing
consumer keeps negotiating the 8-bit stream bit-for-bit. Offered upstream
against ValveSoftware/gamescope#2126.
Ship it as `punktfunk-gamescope`, beside the distro's own binary rather than
replacing it: a Bazzite sysext payload (`build-sysext.sh --gamescope`, which
refuses a binary without the marker), an Arch package, a nix derivation +
`services.punktfunk.host.gamescopeHdr`, and one distro-agnostic build script
the rest call.
The second patch stamps `+pfhdr1` into the `--version` banner. That is not
cosmetic: punktfunk fixes a session's bit depth in the Welcome, before the
display exists and with no way to take it back, so its capability answer has to
be a static property of the binary it will spawn.
Layering is a last resort per the Bazzite docs (slows every OS update, can
block upgrades until removed); a sysext never enters an rpm-ostree
transaction, survives OS updates, and installs/updates with no reboot —
the mechanism Fedora Atomic ships via fedora-sysexts.
- build-sysext.sh wraps the built host+web RPMs into punktfunk-<V-R>-x86-64.raw:
/etc payload relocated to /usr/share/punktfunk/etc (a sysext carries only
/usr), the punktfunk-sysext helper embedded, ID=fedora + VERSION_ID pinned
(merges on Bazzite via ID_LIKE; REFUSED after a major rebase instead of
running soname-broken binaries — both behaviors validated live on Bazzite 43).
SELinux labels are baked in as squashfs pseudo-xattrs from matchpathcon:
unlabeled files run fine for user units but system daemons are DENIED
(udev couldn't read the gamepad rule under enforcing) — validated on-glass.
Refuses duplicate input package names (a stale noarch punktfunk-web next to
the x86_64 one built a chimera image with the dead node launcher once).
- punktfunk-sysext.sh: install/update/status/remove against per-Fedora-major
feeds (…/generic/punktfunk-sysext/f43[-canary]), SHA-256-verified, applies
the udev/sysctl scriptlet work + /etc copies, prints the layering-migration
hint. Live-validated on the .41 Bazzite box incl. service restart + web console.
- publish-sysext-feed.sh + rpm.yml: build + publish the image per matrix leg
(fedver 43/44), canary feeds pruned to 6, stable release assets attached.
- update-punktfunk.sh warns when the sysext shadows a layered install.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
enricobuehler
