Lenovo Thinkpad T420

After proper configuration, every part of the Thinkpad T420 is Linux friendly.

Firmware
The Linux firmware package is needed since the Centrino Advanced-N 6205 AGN wifi adapter requires a specific firmware file:

Kernel
For a pre-built, hand-selected, Gentoo specific .config file: 4.9.0

External resources

 * http://www.thinkwiki.org/wiki/Installing_Gentoo_on_a_ThinkPad_T420 - Another guide to installing Gentoo on the T420.