My issue was simple and common: I wanted to use ChipScopePro on a remote linux computer. The linux drivers provided by Xilinx are very old (as old as ISE), so they don't work on my computer.
There is http://www.rmdir.de/~michael/xilinx/ but I was not able to run it (althought I was in the past).
Plug the Xilinx Cable II. It first appears as:
$ lsusb
Bus 001 Device 011: ID 03fd:0013 Xilinx, Inc.
You then need to program its firmware.
$ sudo fxload -v -t fx2 -I xusb_xp2.hex -D /dev/bus/usb/BUS/DEV
(xusb_xp2.hex can be found in ISE installs).
The device now appears as:
$ lsusb
Bus 001 Device 013: ID 03fd:0008 Xilinx, Inc. Platform Cable USB II
Start the server:
$ sudo xvcd
Open ChipScope.
$ analyzer
In menu JTAG Chain, click on Open Plug-In, and set:
xilinx_xvc host=HOST:2542 disableversioncheck=true
The procotol is documented on https://github.com/Xilinx/XilinxVirtualCable
GPL
The code for xpc.c is derived from: https://sourceforge.net/p/urjtag/git/ci/master/tree/
The code for xvcd.c is derived from: https://github.com/tmbinc/xvcd/blob/ftdi/src/xvcd.c
Discussion about XPCU-II schematics (but 404): https://www.mikrocontroller.net/topic/142358?page=single
Open-source firmware for USB JTAG: https://github.com/mithro/ixo-usb-jtag
An open-source USB JTAG adapter: https://www.geek-share.com/detail/2395472121.html