Help adding support to a new device (ZTE ZXHN H108N V2.5)

Hello community,
I'm gonna try build OpenWrt for a modem isn't supported rn.
OpenWrt supported modems are few and not common in Egypt (where I live).
ISPs limit functionality of their modems with the firmware being ONT ( It has their logo and custom things and so).

The device is called ZTE ZXHN H108N V2.5
Model: ZXHN H108N V2.5
Serial Number: ZTERRT1G9J00632
Hardware Version; V1.1
Software Version: V2.5.4_EG1P6_TED
Boot Loader Version: V1.1.0
DSL Firmware Version: 4926d722
It also has
Processor: RTL8676s
Wlan: RTL8192ER

Unfortunately, the official firmware for this device isn't available online (ONT) but I found some firmware which maybe useful.

This is photo from inside.

On other thread the user @Sparks directed me to look for serial pins so to connect via it and extract the bootloader as a first step. I think these are the pins which is referred to.

So what is next?

RTL8676S = Lexra Architecture.

See for details

Good luck!

You’re very close, but the serial pins are just above in a column with a white square printed around the whole group, and rx,tx,gnd,3.3v labels. But as Tmomas mentioned, the Lexra arch isn’t supported (I was unaware).

if you’re keen to learn you could try soldering headers onto the device, and getting a serial cable to experiment with how that part works (watching/interacting with the oem firmware) , and those would be valuable skills/knowledge even if you aren’t able to add support for this device.

So basically, that means even if I got the bootloader, the the os won't be supporting it. I'll have to work it out and add both the support for the device and the architecture, which is realistically nearly impossible with my skills, right?

That's correct.