Enable TTY

modulename: tty_io.ko

configname: CONFIG_TTY

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Enable TTY
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Allows you to remove TTY support which can save space, and
blocks features that require TTY from inclusion in the kernel.
TTY is required for any text terminals or serial port
communication. Most users should leave this enabled.

source code: