General question about chinese ip camera module. Help, me!

There is a chinese ip camera (without documentation). I could get and change settings on the camera web-interface.

I have a task to develop software for this camera (needed own software with own user interface and full access to the hardware).

I have several questions:

a) How I can start develop for this camera? Where to begin?

b) I found buildroot, can i use it for develop? (needed full control, so may be i'll must create firmware for this camera).

c) Telnet is disabled, how I can to get access to modyfied hardware? May be USB/UART can to help me? How may understand where is USB/UART pins (module without circuit diagram).

Chip: Hisilicon 3518e, Image sensor: AR0130.

I hope, that you help to me, or bring me on the necessary thought.