Original draft (PR #3) speculated wrongly on host-to-SoC mapping:
- hertz and tesla were listed under RK3588. Verified via
/proc/device-tree/compatible: both are raspberrypi,5-model-b /
brcm,bcm2712 (tesla is an LXD container hosted on hertz, so
necessarily shares the host SoC).
- boltzmann (the only actual RK3588 in the fleet, 32 GB, kernel-
dev / MCP hub, 8 W always-on) was omitted entirely.
- noether (Pi 4 / BCM2711, the user's interactive workstation,
where Firefox and mpv actually run) was omitted entirely.
Corrects the per-SoC coverage table:
BCM2712 Pi 5 — higgs, hertz, broglie, tesla (LXD on hertz)
BCM2711 Pi 4 — noether (workstation), dcw3, dcw2
RK3588 — boltzmann
Allwinner H6 — (not in fleet)
Reasoning consequences:
- Pi 5 row is now four hosts but one SoC. Adding a fifth Pi 5
doesn't pressure-test the architecture; substrate decisions
are identical across the row.
- The realistic forcing function for the Pi 4 path is "HW decode
on noether matters and rpivid is still unstable upstream" —
noether is a daily-driver Pi 4 workstation, so this is closer
than the original draft implied.
- The realistic forcing function for an RK3588 caps file is
"AV1 playback on boltzmann matters" — rkvdec doesn't cover
AV1, so Mali Valhall compute substrate becomes the only HW
acceleration option there.
"Re-read this when" list at the top + "Why deferred" section
+ decision log all updated. No change to the architecture sketch
(caps directory, plugin layout, two-backend conclusion) — those
were correct in the original; only the host-to-SoC mapping
underneath them was wrong.
Refs PR #3 (the merged original).
claude-noether