XiongMai's 85H50AI: hi3516ev300 + imx335 with a motorized zoom/focus
module whose MCU shares /dev/ttyAMA0 with the serial console at 115200,
speaking the XM near-Pelco protocol (majestic-webui's btzoom-xm).
Proven on a lab unit driven end to end through the WebUI
(majestic-webui#227).
The defconfig is a byte-copy of firmware's hi3516ev300_lite_defconfig.
customizer.sh (first boot) sets sensor imx335, the upgrade URL, and the
PTZ trio — ptz_control pelco-xm, ptz_port /dev/ttyAMA0, ptz_caps
'zoom focus' (majestic-webui#261) — and deletes the getty line from
/etc/inittab: the MCU owns the console UART. The edit lands in the
overlay and heals itself (an upgrade that wipes the overlay wipes
/etc/custom.ok too, so the script re-runs). S01printk quiets runtime
kernel messages that would drip onto the PTZ wire. The required
hi3516ev300_lite excludes list prunes every non-imx335 sensor blob,
generated from the live lite image so no entry is stale on arrival.
