Unable to connect to hardware target in Vivado

Question

I have Vivado 2015.1 running on Ubuntu Linux 64-bit with a Nexys4 DDR board. I've got the board set up to be programmed using the JTAG (see attached image). Running dmesg on the Linux system I see:
[99537.226929] usb 1-1.2: Product: Digilent USB Device
[99537.226932] usb 1-1.2: Manufacturer: Digilent
[99537.226935] usb 1-1.2: SerialNumber: xxxxxxxx
[99537.229557] ftdi_sio 1-1.2:1.0: FTDI USB Serial Device converter detected
[99537.229631] usb 1-1.2: Detected FT2232H
[99537.230127] usb 1-1.2: FTDI USB Serial Device converter now attached to ttyUSB0
[99537.232437] ftdi_sio 1-1.2:1.1: FTDI USB Serial Device converter detected
[99537.232483] usb 1-1.2: Detected FT2232H
[99537.232819] usb 1-1.2: FTDI USB Serial Device converter now attached to ttyUSB1
I know hw_server is running as I can telnet to port 3121. In the tcl console I have done disconnect_hw_server and connect_hw_server. I do Connect Hardware Target, choose Local Target, but then I see:
[Labtoolstcl 44-26] No hardware targets exist on the server [TCP:localhost:3121]
Check to make sure the cable targets connected to this machine are properly connected
and powered up, then use the disconnect_hw_server and connect_hw_server commands
to re-register the hardware targets.
As a Linux user, I am in the dialout group and I can open /dev/ttyUSB0 and /dev/ttyUSB1 with minicom. Can someone with a Nexys4 board let me in on the secret! I can keep programming bitstreams using a USB key, but it would be much easier to use the JTAG across the USB cable.
Many thanks, Warren
P.S Hopefully my last question for a while.

Answer 1

Thanks aher for pointing that web page. On my Ubuntu 15.04 Linux box, as the root user I did this:
# cd /opt/Xilinx/Vivado/2015.1/data/xicom/cable_drivers/lin64/install_script/install_drivers
# ./install_drivers
The install script creates the file /etc/udev/rules.d/52-xilinx-pcusb.rules with contents:
# version 0002
ATTR{idVendor}=="03fd", ATTR{idProduct}=="0008", MODE="666"
ATTR{idVendor}=="03fd", ATTR{idProduct}=="0007", MODE="666"
ATTR{idVendor}=="03fd", ATTR{idProduct}=="0009", MODE="666"
ATTR{idVendor}=="03fd", ATTR{idProduct}=="000d", MODE="666"
ATTR{idVendor}=="03fd", ATTR{idProduct}=="000f", MODE="666"
ATTR{idVendor}=="03fd", ATTR{idProduct}=="0013", MODE="666"
ATTR{idVendor}=="03fd", ATTR{idProduct}=="0015", MODE="666"
After rebooting my box, I started up Vivdado, created a bitstream, went to the Hardware Manager and found that I have a xc7a100t_0 device on localhost. I was able to send the bitstream down to my Nexys4 DDR board.
Cheers & thanks again, Warren