Seeed Odyssey J4125 GPIO?

[blaz...@gmail.com]

I picked up a couple of these https://www.seeedstudio.com/ODYSSEY-X86J4125864-TELEC-p-4918.html. They have an "Arduino" GPIO Header, and a "Raspberry Pi" GPIO header. From what I can surmise, the Arduino header comes off of a SAMD21 chip and I belive it's connected through USB, so I'm not really interested in that one. The Rpi GPIO header is a bit more of a mystery. These pins can be controlled through the bios and they show up in /sys/class/gpio, so the Linux GPIO driver is aware of them.

I know there's some gurus around here. This page contains some info about using the GPIO through Linux. https://wiki.seeedstudio.com/ODYSSEY-X86J4105-GPIO/. Anyone have any idea on what other information I'd need to dig up to get (someone other than me) started with setting up a hal driver or something useful in LinuxCNC?