Rock3a Android Image with serial port support

[ks_D.E]

the forum shows android support serial port:

Android 11 Image For Rock3A Is Now Available

Android 11 image and also source code for Rock3A is now available(Download) Release for Radxa Rock 3A Currently support hardware/feature Radxa Wireless module A1/A2/A3 module 1000Mbps Ethernet USB2.0 x2, USB3.0(with mtp,adb) HDMI output(up to FullHD@60Hz) SD card auto mount Serial Port Headphone jack play&record Video decode(H.264, H.265, up to 3840x2160@60P) RKupdate&GPT image support Power key Known issues: Sdcard/Nvme boot HDMI audio output

which one is enable and how to custom a image with multi serial ports.