Download the Project
Download Ulf's pcileech-fpga project, extract it and copy the folder you need for your DMA device to another location.
*I have a Captain DMA v4 35T, I will therefor use the
PCIeSquirrelfolder
Sometimes Vivado will fail to generate the project files or fail when generating the Bitstream copy the folder to a location that doesn't have any special characters in the folder names and isn't too long, keep it simple.
Example
C:/PCIeSquirrel
This is where you'll be working on the firmware
Note
Ulf Frisk is the author of this project, without him it wouldn't be possible to use a DMA device
If you want to support his work, go to his donation page on Github