A Xilinx ZYNQ Linux FPGA Board for Under $20

One of the comments links to a GitHub page [1] with some reverse engineering info on one of the boards mentioned.

[1] https://github.com/xjtuecho/EBAZ4205

7 months old video ,this looks like same board. Now they solder SD card https://www.youtube.com/watch?v=b6g5tNZZnVc