-This library emulates Jungo Windrvr USB functions in userspace which are
-required by XILINX impact to access the Platform cable USB. With this library
-it is possible to access the cable without loading a proprietary kernel module
-which breaks with every new kernel release. It uses the USB functions provided
-by the libusb userspace library instead and should work on every kernel version
-which is supported by libusb. It was written against impact from ISE Webpack
-9.1SP1 and will very probably not work with older impact versions (<9.1).
+This library emulates Jungo Windrvr USB and parallel port functions in
+userspace which are required by XILINX impact to access the Platform cable USB
+and Parallel Cable III.
+With this library it is possible to access the cables without loading a
+proprietary kernel module which breaks with every new kernel release. It uses
+the functionality provided by the libusb userspace library for USB access and
+the kernel interface at /dev/parport0 for parallel port access instead and
+should work on every kernel version which is supported by libusb and supports
+ppdev. It was written against impact from ISE Webpack 9.1SP1 and tested with
+the following software:
+
+ * ISE Webpack 9.1SP3
+ * ISE Webpack 9.1SP2
+ * ISE Webpack 9.1SP1
+ * ISE Webpack 8.2SP3
+ * ISE Webpack 8.1SP3
+ * ChipScope 9.1.03i
+ * ChipScope 9.1.02i
+ * ChipScope 8.2.04i
+ * EDK 8.2.02i
Build the library by calling `make'.
$ export LD_PRELOAD=/path/to/libusb-driver.so (for sh shells)
$ setenv LD_PRELOAD /path/to/libusb-driver.so (for csh shells)
$ impact
+
+The source for this library can be found at:
+http://cvs.zerfleddert.de/cgi-bin/viewcvs.cgi/usb-driver/
+
+The main website is located at:
+http://www.rmdir.de/~michael/xilinx/
+
+
+Notes for the USB cable
+=======================
+
+To use the device as an ordinary user, put the following line in a new
+file in /etc/udev/rules.d/ and restart udev:
+ACTION=="add", BUS=="usb", SYSFS{idVendor}=="03fd", MODE="666"
+
+
+If your cable does not have the ID 03fd:0008 in the output of lsusb,
+the initial firmware has not been loaded (loading it changes the
+product-ID from another value to 8). To load the firmware follow
+these steps:
+
+1. If you have no /etc/udev/rules.d/xusbdfwu.rules file, copy it from
+ /path/to/ISE/bin/lin/xusbdfwu.rules to /etc/udev/rules.d/xusbdfwu.rules
+
+2. Install the package containing /sbin/fxload from your linux distribution.
+ It is usually called "fxload"
+
+3. copy the file /path/to/ISE/bin/lin/xusbdfwu.hex to /usr/share/xusbdfwu.hex
+
+4. restart udev and re-plug the cable
+
+
+Notes for the parallel cable
+============================
+
+To access the parallel port from userspace, the kernel needs to be built with
+the features "Parallel port support" (CONFIG_PARPORT), "PC-style hardware"
+(CONFIG_PARPORT_PC) and "Support for user-space parallel port device drivers"
+(CONFIG_PPDEV) builtin or as modules. If these features are built as modules,
+they need to be loaded before using this library.
+These modules are called:
+parport
+parport_pc
+ppdev
+
+
+To use the device as an ordinary user, put the user in the group 'lp'
+
+
+If you have an almost compatible cable which works with other software but not
+with Impact, try adding -DFORCE_PC3_IDENT to the CFLAGS line in the Makefile.
+This enables a hack by Stefan Ziegenbalg to force detection of a parallel cable.
+
+
+Parallel Cable IV is currently only supported in 'compatibility mode', as no
+attempt to configure the ECP registers is done by this library.
+
+
+If you get "Programming failed" or "DONE did not go high" when programming
+through the parallel cable with Impact 9.1, make sure to have the option "Use
+HIGHZ instead of BYPASS" enabled in Edit -> Preferences -> iMPACT Configuration
+Preferences.
+If you are using batch mode, add the following line to your cmd file:
+setPreference -pref UseHighz:TRUE
+(This problem also occurs on windows and when using the real windrvr in linux and
+is solved with the same workaround. Impact 8.2 is working fine with the same
+boards and designs)