How to create BSP

Hi my friends

I want to create the BSP for the DE1-SoC kit "http://www.terasic.com/downloads/cd-rom/de1-soc/DE1-SoC_opencl_BSP_16.0.zip", I want how they did it in the photo.

I know ".cl" and ".cpp" extension do in Visual Studio, but other file don't know how I do it?

I wait for your support, I appreciate the your help,Thank you in advance.