10th October 2015
I upgraded my OnePlus One smartphone from Oxygen 1.0.0 to 1.0.3, see Installing OxygenOS 1.0 on the OnePlus One Smartphone.
Download OxygenOS 1.0.3 from OxygenOS 1.0.3 with the latest Stagefright patches, and check MD5. Then upload the zip-file.
adb push ~/Download/ONE_12_A.01_150827.zip /sdcard/
It is stated in Oxygen 1.0.2 Release with Stagefright security patches that "If you are already on OxygenOS, this update does not require a reset." I had to factory reset my phone as TWRP didn't recognize the system partition; it was encrypted, although encryption in my previous efforts never worked. It looks like it worked for TWRP only.
Shut down phone, and reboot with power-button and volume-down pressed, boot into TWRP, select your image on
/sdcard. That's it.
These are the versions displayed:
Using OxygenOS 1.0.3 I noticed the following:
For an answer as why not update to a higher OxygenOS version see OxygenOS 2.0 Q&A:
As for all of you wondering when the OnePlus One will get an update to the latest OxygenOS version, the answer is that we are working on it but the official date is not quite set yet. Since 2.0 is optimized for Snapdragon 810, it will take us a bit of time to port things over. In the meantime, the OnePlus One will still be officially supported by CM.The OnePlus One has a [Snapdragon 801](https://en.wikipedia.org/wiki/Qualcomm_Snapdragon).
For the OnePlus One, Cyanogen OS will be updating to Marshmallow in the first quarter of 2016. We created a community build of OxygenOS for the OnePlus One, but this isn’t what the product officially ships with. We will be updating the community build of OxygenOS for the OnePlus One when time allows.
Update 23-Jan-2016: Oxygen 2.1.4 for the OnePlus One is out, see https://forums.oneplus.net/threads/oxygenos-2-1-4-for-the-oneplus-one.425544/