Found by Adrian Matoga. Source site: http://ubuntuforums.org/showthread.php?t=1547435

• 1. Copy the udev rules and adapt the file to the new udev-version

sudo cp /opt/Xilinx/13.4/ISE_DS/ISE/bin/lin64/xusbdfwu.rules /etc/udev/rules.d/50-xusbdfwu.rules
sudo sed -i -e 's/TEMPNODE/tempnode/' -e 's/SYSFS/ATTRS/g' -e 's/BUS/SUBSYSTEMS/' /etc/udev/rules.d/50-xusbdfwu.rules

If your machine is running 32-bit Linux change lin64 to lin on the first line.
Change /opt/Xilinx/13.4 on the first line if your path to Xilinx or ise version are different.

• 2. Copy the hex-files used by different Xilinx cables to /usr/share and make them readable by regular users

sudo cp /opt/Xilinx/13.4/ISE_DS/ISE/bin/lin64/xusb*.hex /usr/share/
sudo chmod 644 /usr/share/xusb*.hex

Again, change path and lin64 as you need.

• 3. Install fxload, which is used by the rules, and libusb-dev, which is needed by iMPACT

sudo apt-get install fxload libusb-dev

• 4. Restart udev

sudo restart udev

• 5. To make planAhead work two script files must be edited.

sudo sed -i -e 's/#!\/bin\/sh/#!\/bin\/bash/' /opt/Xilinx/13.4/ISE_DS/PlanAhead/bin/planAhead
sudo sed -i -e 's/#!\/bin\/sh/#!\/bin\/bash/' /opt/Xilinx/13.4/ISE_DS/PlanAhead/bin/loader

Again change path and version.