About understanding ekf2 code of px4

[ajaybhatt003]

Hello, I am a graduate student. I have just started working on ekf2 (https://github.com/PX4/Firmware/blob/master/src/modules/ekf2/ekf2_main.cpp) code of px4 firmware. Kindly can you help me to understand it. I am currently referring to this site http://ardupilot.org/dev/docs/ekf2-estimation-system.html but not sure that the same code is written in cpp as ekf2 for px4 firmware. Please reply when you get time if possible provide me literature which explains about ekf2 code. Thanks in advance.