Measured on onefinity.local (Pi 3, Raspbian Stretch, bbctrl 1.6.7).
Before -> after:
bbctrl listen boot+20.6s -> boot+12.4s (-8.2s)
host -> /api/config/load 28.2s -> 22.5s (-5.7s)
The 4 changes (each independently revertable):
1. scripts/bbserial-rebind.service: do the bbserial unbind + reload
in a dedicated unit ordered Before=bbctrl.service, instead of in
rc.local AFTER bbctrl is already listening on the serial port.
Eliminates a full bbctrl restart mid-boot.
2. scripts/bbctrl.service: drop "After=network.target". bbctrl talks
to the AVR on a local serial port and to the LCD on I2C; it does
not need DHCP / network-online to come up. Also adds explicit
ordering after the new bbserial-rebind unit.
3. scripts/rc.local.fast: trimmed rc.local that no longer touches
bbserial and backgrounds 'startx' so chromium launches in
parallel with bbctrl rather than after rc.local finishes.
4. src/py/bbctrl/Planner.py: lazy-import camotics.gplan. Costs ~130ms
on cold cache, deferred from import-time to ctrl.mach init.
5. (bonus) src/py/bbctrl/Log.py: tolerate FileNotFoundError in
_rotate(). The improved boot path exposed a pre-existing log
rotator bug that crashed bbctrl on first start when bbctrl.log.16
was missing.
