Adding OpenWrt support for tp-link Archer AX55 Pro V2 (US) (MT7981B, 2.5GE x2)

Hi. Community!

I am not a developer. I create this thread hoping those knowledgeable people will notice this rather cheap yet with good hardware router. It’s based on MT7981B.

SoC: MT7981B
RAM: 512 MB
flash: 128 MB(??)
Ethernet: 2.5GE x2, 1GE x3
WiFi: AX3000, MT7976DAN
USB: USB 2.0
power: 12V 2A

FCC ID: https://fccid.io/2AXJ4AX55PRO
website: https://www.tp-link.com/us/home-networking/wifi-router/archer-ax55-pro/

photos from FCC:

Thank you for your attention!

congratulation
now you are

at the bottom of page 3 at "60mm" looks like a serial.
Don't connect the "red wire" aka 5V from you serial here

You can find some things without opening the device.
Firmware encrypted...
Search GPL sources from OEM if any
try this TP Link firmware decryption
Then binwalk (-eM) to find DTB file, chop it out with dd
Then use dtc to convert it to dts.

the exploit to enable telnet also worked on the ax55 pro, tested on tplink firmware 1.0.5.