ApexNanshan 8A2130h

A 4.X.X based firmware used for testing iPhone devices. Found on an iPhone 4.

Toolkit
After booting up, SwitchBoard.app screen shows up allowing you to choose different options.

They consist of:
 * AT Command
 * BurnIn
 * CameraFA
 * GrapeCal
 * LcdUTest
 * Operator
 * Rumble
 * SkankPhone
 * Soundwave

Binaries
The firmware includes standard set of UNIX binaries. apt-get is present suggesting that there is an internal APT repository.