- Trace reads /proc/stat btime and /proc/uptime at import so every
event in /api/diag/timing can be expressed as 'seconds since
power-on' (uptime_at_anchor + ev.t).
- Web.StaticFileHandler.prepare emits 'web.first_root_get' the first
time chromium hits / or /index.html, so we can see when the kiosk
browser actually started loading the UI on cold boot.
Add a lightweight, self-contained phase tracer for measuring end-to-end
bbctrl restart and Pi boot time. Disabled by setting BBCTRL_TRACE=0.
- src/py/bbctrl/Trace.py: monotonic-anchored event log + sd_notify helper.
- bbctrl/__init__.py: marks for imports, args parsed, ioloop, web init,
listen, and an sd_notify READY=1 once HTTP is bound.
- bbctrl/Ctrl.py: spans around each subsystem (avr, i2c, lcd, mach,
preplanner, jog, pwr, hooks, aux, mach.connect).
- bbctrl/Comm.py: avr.firmware_rebooted mark.
- bbctrl/Web.py: TimingHandler (GET /api/diag/timing) and
UITimingHandler (PUT /api/diag/timing/ui), plus a ws.first_open mark.
- src/js/restart-timing.js + app.js: UI-side performance.now() marks
(script.load, ws.open, ws.first_msg, ui.first_state, window.load),
posted once to the controller.
- scripts/bbctrl.service: stdout/stderr -> journal so TRACE lines are
visible via journalctl -u bbctrl. (Was StandardOutput=null.)
Revert: git revert this commit. To disable at runtime without
reverting, set BBCTRL_TRACE=0 in the bbctrl service environment.
