raspberryPi HAT
Hardware Attached on Top
Introducing Raspberry Pi HATs - Raspberry Pi
Device Trees, overlays, and parameters - Raspberry Pi Documentation
use a Device Tree (DT) to manage some resource allocation and module loading by default.
to allow
HAT modules
to be auto-configured
https://www.raspberrypi.org/wp-content/uploads/2014/07/HAT-Pi-Flexis.jpg
Raspberry Pi 3 のDevice Tree Sourceを読む - Qiita
自分の知らない部分
Device Tree