Custom made routers

Hi Everyone,

I'm new to openwrt based routers. I have a custom made router which has 4G LTE module for SIM cards. So how to find the firmware for it. What kind of information needed to get the firmware or develop the firmware

Unless it's custom made by taking a well known model and plugging an LTE modem into a USB port... it won't have a firmware. To develop a new firmware takes skills that if you had you probably wouldn't be asking the questions you are asking.... so... at the moment it's not looking great.

Perhaps you can provide some information about this router, like photos of the motherboard or some descriptions of the SOC chipset, flash chips, RAM chips, etc.?