SteamOS 3 image variant for PS5, built by extracting the rootfs from Valve's official Steam Deck recovery image and swapping in our linux-ps5 kernel.

Source

Upstream: https://steamdeck-images.steamos.cloud/recovery/steamdeck-repair-latest.img.bz2 (Steam Deck recovery image; SteamOS Holo Arch-based.)
~3.4 GB compressed bz2, ~10 GB decompressed.
Valve CDN — no per-IP throttle observed; first-time cache pull on a cold runner is ~3-5 min, subsequent runs are instant via /data/cache/ps5/downloads/.

What the build does

Resolve steamdeck-repair-latest.img.bz2 → its dated filename so the cache key is stable.
Decompress → losetup -P.
Mount the first erofs partition (rootfs-A; A and B are identical) read-only, cp -a to $CHROOT.
Mount the first ext4 < 2 GB partition that contains /lib (var-A), cp -a to $CHROOT/var — SteamOS splits /var off the rootfs and first-boot fails without it.
Extract our linux-ps5-*.pkg.tar.zst and merge usr/, boot/, etc/ into $CHROOT.
Delete SteamOS's linux-neptune kernel + modules so grub boots ours.
depmod -a $KVER.

The standard image-builder flow then packs $CHROOT into an ext4 image with our EFI partition.

Caveats

The Steam UI session expects the Deck's jupiter hardware quirks (gamepad, ALS, fan curve daemons) — most of those won't apply on PS5. Falling back to plasma desktop on the first session is normal.
SteamOS is read-only by design (steamos-readonly enable). The image we build here is regular ext4; if you want the read-only A/B atomic experience, that needs a separate variant.