leXia

After installing the firmware shown in the link and requesting modifications by decompiling your dtb, there's been some progress, but it's still not working yet.
 
However, I'm hopeful that with a little more effort, it should work.

For this device, ttyS2 is used for BT, but the problem was that the system was trying to use it for logging. After modifying that part in boot.cmd and rebooting, the firmware came up.