OnePlus One Marshmallow update starts rolling out
OnePlus One has started receiving its Marshmallow update which is based on Cyanogen OS 13 with version ZNH0EAS26M. The update weighs in at about 508 MB and should be downloaded over WiFi.
With the new Marshmallow update you are also getting the March security update, then there's App Permissions, Doze mode for better battery life on standby and more.
Cyanogen OS 13 for the OnePlus One is being rolled out gradually, so you may not get it just today. But if you are feeling a bit more adventurous you can flash the update file from here, using recovery or the Cyanogen Update Tracker.
Next in line for the update is the OnePlus 2, which already has Oxygen OS 3.0 beta based on Android Marshmallow 6.0.1 available for it.
Via: OnePlus Forums