$ sudo apt-get update
$ sudo apt-get install gcc-arm-none-eabi 

gcc-arm-none-eabi is installed in your system.

Make ensure the gcc-arm-none-eabi package were installed using the commands given below,

$ sudo dpkg-query -l | grep gcc-arm-none-eabi *

You will get with gcc-arm-none-eabi package name, version, architecture and description in a table

gcc-arm-none-eabi package basic information: