Back in February, a commit to the Chromium Gerrit revealed that "secret" 4K Chromebooks were in the pipeline. The comment attached to the commit, at the time, seemed like just a wink and a nod to the future possibility, but it appears there may be a specific name attached to Chrome OS' 4K future. "Atlas" is the codename for a 4K-equipped board recently discovered in a file on Google's Chromium Git. 

For the uninitiated, Chromebooks, like Android phones, have a secret name attached to their hardware. The original 2016 Pixels were Sailfish and Marlin, Google's Pixelbook is Eve, and this upcoming hardware (whatever it ends up being) is named Atlas.

The full excerpt, which really just details the resolution of the framebuffer/screen and localization options, is just below:

atlas:
# 3840x2160, boots recovery image on USB ports.
screen: [3840, 2160] sdcard: False
hi_res: [en, es-419, pt-BR, fr, es, it, de, nl, da, nb, sv, ko, ja, id, th, ar, ms, zh-CN, zh-TW, fi, pl]

Right now, all we know is that Atlas, whatever it is, can support a 4K panel, and it's probably a Chromebook. Devices without screens built in (i.e., Chromeboxes) usually specify in a comment that there is "no standard panel size," and define much lower resolutions than 4K.

Other useful details, like who is manufacturing it or what specs it has, are lacking. Atlas may even just be a development board, destined to never see the light of day.

Whatever Atlas is, though, it looks like Google's testing Chrome OS on 4K hardware.