bmartini/zynq-uflow

Linux UIO Driver for the Zynq AXI4Lite interface

Zynq uflow configuration Driver

This Linux driver has been developed to run on the Xilinx Zynq FPGA. It is a userspace input/output driver (UIO) that enables the passing of register values to and from the Zynq FPGA. Userspace applications use this UIO driver to configure and control the accelerator operations.

Compile

Kernel modules need to be built against the version of the kernel it will be inserted in. It is recommended to uses the Linux kernel maintained by Xilinx.

git clone https://github.com/Xilinx/linux-xlnx.git

The driver module can be compiling outside of the Linux kernel source tree. A variable 'KDIR' in the Makefile is used to point to the kernel source directory. The default value has it pointing to the default Linux install location for kernel sources. However, if cross compiling or if the sources are in a non-default location the value can be overridden using an exported environmental variable or as an argument passes into the make command.

cd zynq-uflow/dev/
export KDIR=../../linux-xlnx
make

or

cd zynq-uflow/dev/
make KDIR=../../linux-xlnx

Inserting Module

Use of the driver module requires it to be inserted into the running Linux kernel. Once inserted it will automatically create a character device file in '/dev' called '/dev/uflow-cfg'. However, the default permissions will not allow non-root users to read/write to the file. These permissions can be overridden by installing the udev rule file found in this projects 'util' directory into the systems '/etc/udev/rules.d/' directory. Alternatively, once the modules inserted the permissions can be changed manually using 'chmod'.

sudo cp util/80-uflow.rules /etc/udev/rules.d/
sudo insmod dev/uflow.ko

or

sudo insmod uflow.ko && sudo chmod 666 /dev/uflow-cfg

To remove the module.

sudo rmmod uflow

To install the module and have it loaded at boot, first install the udev rule as shown above and then follow the below instructions.

sudo mkdir -p /lib/modules/$(uname -r)/extra/
sudo cp uflow.ko /lib/modules/$(uname -r)/extra/
sudo depmod -a
sudo modprobe uflow
sudo sh -c 'echo "uflow" >> /etc/modules'

Build and install uflow library

The uflow library has to be built and installed before the demo applications can be compiled. The library offers a number of generic functions for use in configuring the accelerator. For example, it can write a single values or pass in an entire array of values.

cd lib/
sudo make install

Compiling and Running Demo

The demo application runs a simple configuration test.

cd demo
make