Evdev

evdev is
 * The open source input driver for many input devices like keyboards, mice, joysticks and more.
 * The short name of the Linux kernel's event interface (CONFIG_INPUT_EVDEV), needed for libinput.
 * The USE flag.

Kernel
You need USB support, if you have an USB input device. Also you need to activate the following kernel options:

Some USB mice (e.g. Logitech G5 and Razer Naga 2014) additionally need the following option:

Keyboard layout
To set the default layout copy the file to  and edit the keyboard section, e.g. for a German layout:

For more info please read the Configuring the keyboard.