GPD Micro PC serial port

Hi,

for mobile usage I've got Micro PC from GPD, some description and data
here:

https://www.amazon.com/Industry-Portable-Computer-Notebook-Graphics/dp/B07QYZHM8F

I managed to install dual boot FreeBSD/Windows here. Working with
FreeBSD 13 here, it was possible to verify working ethernet, wifi, X
on both internal display and HDMI connected monitor, and all basic
devices.

I've put dmesg from at https://dmesgd.nycbug.org/index.cgi?do=view&id=6461

There is one think I'd like to get into working state - serial port. In
Windows, it is COM2 with standard I/O address and IRQ, however, I see
nothing in FreeBSD... has somebody any hint for me?

I did not work with bluetooth, yet.

Regards,
Milan