This is a device that behaves like Hodor.
It answers to your calls with nothing but Hodor.
Really useful for, uh... Not much. Oh well.
This repo contains code to build a Linux kernel module that creates a device, /dev/hodor.
Has been tested on Ubuntu 14.04 and should work on Debian too.
Largely based on http://www.linuxdevcenter.com/pub/a/linux/2007/07/05/devhelloworld-a-simple-introduction-to-device-drivers-under-linux.html.
First you need the module-assistant package, which installs packages and configures the system to build out-of-kernel modules. Install it with:
$ sudo apt-get install module-assistant
That should be enough to build the module. To build it, run:
$ make
Then, to install the module, use:
$ sudo insmod ./hodor_dev.ko
Now you should be able to read from /dev/hodor. Note that this requires root.
$ cat /dev/hodor
To uninstall the module again, use:
$ sudo rmmod hodor_dev