evidence · 5.1 KiB

README.md

Committed at docs/evidence/mainline-system-trial/uart-observer-physical-2026-10-03/README.md. This is what grounds the requirements that cite it.

Open raw source

Autonomous UART observer: physical READY boundary

Evidence class: physical board UART runtime, with a separate limited private camera observation. Source revision 11d49eb0f72d28c0f9cdc070fea4662410451c10; integration branch integrate/mainline-probe-path, bounded base 65578ff2. The coordinator held the build slot, then the board/serial reservation.

The matching observer bundle is /nix/store/16cpjjiifxgwyb6bndhi39vfmlvcdw6h-k230-mainline-uart-observer-boot-files; system /nix/store/k1zjqdn4ks7b5dd7b3py6cavhf85g6j6-nixos-system-nixos-26.11.20260919.20b1ddd. Kernel remains the tested 9vdk79… / Linux 7.3.0-rc5. Exact public artifact/source digests and immutable paths are in result.json. The original five-clock SD1 support is retained; no clk_ignore_unused, kernel patch, persistent boot selection or normal profile change was introduced by this diagnostic.

Preparation and command

The first wrapper build failed because cp -a retained a read-only output directory. The corrected wrapper built, but controller preparation rejected its missing helper in the system-derived closure inventory. Both were caught before UART. The optional system now retains the same helper through system.extraDependencies; the final rebuilt bundle passed standard matching Image/DTB/ramdisk/hash/CRC checks and the controller’s full actual archive and closure checks. These preparation limits and fixes are recorded in the host note.

The native helper’s 18 tests and controller’s 26 tests passed on the integrated source. No tests were repeated to claim a physical result. Under the build lock, nix build .#kernelMainlineUartObserverBootFiles --no-link --print-out-paths --max-jobs 1 --cores 16 passed. Actual initrd inspection verified the ELF64 little-endian RISC-V helper, exact version marker/drop-in and unchanged original debug unit. Both the kernel Image and normalized DT hardware remained equal to the proven base. Four new closure paths (634 total bundle closure, 630 system inventory) were exported and staged; transfer SHA, store import, separate observer GC root and staging script returned RC=0.

From the integration worktree, with Python3.14 and dtc tools:

nix shell --inputs-from . nixpkgs#dtc --command \
  python3 tools/mainline-drm-uart-observer-trial.py \
  --bundle /nix/store/16cpjjiifxgwyb6bndhi39vfmlvcdw6h-k230-mainline-uart-observer-boot-files \
  --manifest "$HOME/tmp/k230-mainline-uart-observer-board/candidate-manifest.json" \
  --normal-report "$HOME/tmp/k230-mainline-uart-observer-board/normal-report.json" \
  --blkid-result "$HOME/tmp/k230-mainline-blkid-board/trial-result.json" \
  --log "$HOME/tmp/k230-mainline-uart-observer-board/observer-uart.log" \
  --result "$HOME/tmp/k230-mainline-uart-observer-board/observer-result.json"

Observation and limits

Protected normal preflight passed before the volatile boot; each U-Boot load and CRC and printed volatile bootargs passed the controller’s checks. Fresh mainline and systemd 261.2 banners were observed. One complete, fresh, CRC-checked sequence 0 READY frame (83 payload bytes) was observed. It reports the guard marker, main shell PID and 12-second window. The matched helper emits this only after its initial guard and getter operation finish; this narrows the observed stop but does not publish any counter values or identify a kernel cause.

No before/after/return frame or primary shell prompt followed. The host reception gate therefore sent zero receipt commands. Return acknowledgement was unknown after 60 seconds; passive recovery continued to the 180-second bound after READY. No new SPL/normal boot was observed. The controller exited 2 with recovery-required-unknown; no candidate input or reboot retry followed.

Final UART write timestamp: 2026-10-03T06:15:42.034494+00:00. Controller result written: 2026-10-03T06:18:42.042507+00:00. Private raw UART: 53,905 bytes, SHA256 7fefbf17759b9ea8accd808a3e6cb9fcdf92ad811cb730eba62118450ddd8427. Its final printed kernel timestamp is 8.103408. The raw log, volatile nonce/boot IDs and transfer URL remain private. A separately reserved C920 camera capture showed boot text with glare; it does not establish readable candidate identity, a usable root, or deliberate touch. That private frame is not published.

The user pressed reset. Protected normal postflight passed with a fresh boot ID, the exact system/profile/kernel/init, three active shell services, all eight unchanged protected boot hashes and registration-marker absence. Qualified normal Home IPC returned RC=0, and a separately reserved private camera frame visually showed Home icons, clock and background. Glare limits detail; it is not published and is not a mainline/touch proof. This proves operator-reset recovery; automatic return from the observer remains UNVERIFIED. Task 5b.5 remains open: ordinary usable mainline root, panel photograph, deliberate glass touch and protected return are not satisfied by READY or host checks. Further source review must distinguish helper early exit, kernel progress/console output and RX delivery; none is claimed as the cause here.