Debugging fpga matrix creator

Hello,
I would like to to debug some signals inside the fpga so I guess the options are use an external jtag from xilinx for external debuging or maybe exits another alternative to debug signals from raspberry I don’t know.

for first option since there is no schematics I can’t see where I can connect the external jtag without modify the board for debuging because the only jtag signals are routed to the raspberry pi gpio connector. I’m rigth?.

Thanks!.

I would be interested in a detailed schematic as well.

they say the schematics are not available…