Simple example on how to create a IOCTL driver for Linux. This can be used for simple testing purposes:

• Access to a special register from kernel mode to get the result in user mode. For example Arm register from CP15 processor.
• Access to some memory mapped region
• ...

This repo contains the following folders:

• ioctl_interface.c is the source code of the driver. The function that should be modified to add more IOCTL
• ioctl_dev.h is the header file
• ioctl.h contains the list of IOCTL codes. This list is also included in the application
• Makefile to build the driver. If the driver is cross-compiled, the variable KDEV should be adjusted

• ioctl_app.c shows an example to access the driver and get the returned value
• Makefile to build the application

Load the driver ioctl. This probably needs sudo permissions!