A demonstration of how to send an interrupt from the Cyclone V FPGA to the HPS and handle the IRQ in Linux.

Includes Verilog description which triggers interrupt when a switch or push button changes state, as well as Linux kernel sysfs driver and userspace command-line program.

1. Go into the fpga directory.
2. Open interrupt_example.qpf in quartus.
3. Open the soc_system.qsys file in Qsys and generate the system.
4. Compile the SOF file and program it onto the FPGA.

1. Go into the software/kernel directory and run make.
2. Copy the fpga_uinput.ko file to the SDCard.
3. On the HPS, run echo 1 > /sys/class/fpga-bridge/lwhps2fpga/enable.
4. Run insmod fpga\_uinput.ko.
5. Make sure that the file "/sys/bus/platform/drivers/fpga_uinput/fpga_uinput"

1. Go into the software/userspace directory and run make.
2. Copy the readstate binary to the SD card.
3. Run the executable on the HPS.
4. Start flipping switches and pushing buttons. The program should print out information when an input changes state.