i have spent a long time to get JTAG to work on my Arduino MKR Vidor 4000. It now finally works and I have put everything together in a nice litte, easy-to-use package. That way, uploading the bitstream is handled for you, as well as data transfer to and from the FPGA. Everything is set up to be as universal as possible, just make sure to read the readme.
The url to the Github repository is the following:
Take a look at it, use it and please share if it works.
I would really appreciate any feedback in the repository to make it better for everyone!