The official OnePlus One does not show how to install OxygenOS on OnePlus One using Linux OS. So here is a summary on how to do it which take 15 mn.
I believe you know what you are doing. Your data will be wiped out completely, so prepare a backup before doing any thing from this tutorial.
Download required files as indicated here with instruction of Mac OS and OPO2.1.4_Patch_Mac.zip
Install Android development tools (android adb and fastboot):
sudo apt-get update sudo apt-get install android-tools-adb android-tools-fastboot
Extract OPO2.1.4_Patch_Mac.zip and cd into it
Check Device Status:
sudo fastboot devices
sudo fastboot oem unlock
Flash Oxygen Recovery and appsboot patch
sudo fastboot flash recovery sys/recovery.img sudo fastboot flash aboot sys/emmc_appsboot.mbn
Boot into Recovery
sudo fastboot boot sys/recovery.img
If the system don’t go to recovery turn it of and press power+volumen down button again.
Then you can either follow the Mac instructions items from 11 or Wipe the cache and data and use USB install from the recovery, then you have to run this command of course with your phone connected via usb to your laptop/pc:
sudo adb sideload ../OnePlus_Bacon_OxygenOS_201601190107.zip
Just wait until the install is done and then reboot the phone. You have now successfully installed OxygenOS on your phone.