Rebuilt with KBUILD_BUILD_USER/HOST/TIMESTAMP pinned. Without them the kernel
bakes the builder's user@hostname and wall-clock build time into /proc/version,
which publishes operator identity in a public artifact and makes the build
unreproducible. Pinned, anyone can rebuild and diff the bytes — the only trust
story available for an unsigned community kernel.
The installer refuses to run on anything but a Pi 4, refuses a mismatched
image/modules pair (vermagic failure means no /dev/pps0 on a kernel that
otherwise boots fine — silent and miserable to debug), verifies SHA256SUMS,
never touches kernel8.img, and leaves rollback as deleting one config.txt line.
Boot-tested on the Pi: Stratum 1, 273 ns offset, PPS handler confirmed NOT
threaded. Binaries ship as release assets, not in git.
Nine cuckoos on an idle click is a lot. There's no singleclick event and click
always fires before dblclick, so the single call is deferred by one double-click
interval (260ms) and cancelled if a second click lands.
The clock strikes the current hour. Two things in it are mechanism rather than
decoration:
- The pendulum TICKS. steps(2) over 2s = two discrete positions, one per second.
That is what an escapement does — it chops continuous energy into countable
ticks. A swept pendulum would contradict the entire site.
- The call is SYNTHESIZED, not sampled. A real cuckoo clock is two wooden pipes
a minor third apart (6:5, so 700 Hz -> 583 Hz), pushed by a bellows. That's
twenty lines of Web Audio: triangle pipes with a slight pitch sag as the
bellows empties, plus a puff of bandpassed noise for the breath. The sound is
the mechanism rebuilt, and the hero ships zero bytes of audio.
The talk is regenerated for a public audience — the finding, not the
procurement case. Transcript ships with it: audio is the alternative to reading,
never a replacement for the text. preload=none so the 800 KB only downloads for
readers who actually press play.
What the Raspberry Pi time-server guides get wrong on a Pi 4, with the
measurements. The headline artifact is a four-line pps-gpio patch: PREEMPT_RT
force-threads IRQ handlers, and pps-gpio takes its timestamp inside its handler,
so the realtime kernel puts a scheduler between the electrical edge and the
clock. IRQF_NO_THREAD takes RMS offset from 2468 ns to 199 ns.
- kernel/ the patch
- dashboard/ live status page (position hidden by default)
- docs-site/ the write-up (Astro/Starlight, brass, no tutorial section)
