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unofficial Android 5.1.1 update OnePlus One with SlimLP ROM

The OnePlus One is famous its Cyanogenmod 12S operation system but a big problem is the speed in which new updates are rolled out to the OnePlus One. Currently, the latest Android 5.1.1 version isn’t available on the OnePlus One but the OnePlus One can be updated with an unofficial Android 5.1.1 update OnePlus One using SlimLP ROM.

Bellow is an in-depth guide on how to install Android 5.1.1 On the OnePlus One using the SlimLP ROM ( the latest version includes several additional changes, here is a full list of the SlimLP changelog:

  • Compiled with a custom toolchain Sabermod for more performance and better battery life
  • Compiled with the GCC optimisation level -O3
  • Android 5.1.1 Lollipop support.
  • Compiled with strict-aliasing compiler optimisation
  • Added patches to fix GCC strict-aliasing violation rules
  • Added ARMv7 optimised string handling routines for more smoothness and more memory optimisation
  • Disabled SQLite fsync to increase I/O performance
  • Cherry-picked some AOSP bug and memory leak fixes
  • Cherry-picked some KitKat bug and memory leak fixes

Before installing Android 5.1.1 update OnePlus One

Before upgrading your OnePlus One to Android 5.1.1, Install Custom ROM or modify Android in any way we always highly recommend you create a full system backup. There are several methods to Create a Backup in Android 5.0 Lollipop, bellow we will go step by step on how to successfully create a backup and restore it in case something goes wrong while updating OnePlus One to Android 5.1.1:

Create Android 5.1.1 Lollipop Backup:  We have already covered this in an in-depth guide on how to create a Nandroid backup Method 2: Create a cloud backup. We have already covered this in an in-depth guide on how to create Android backup to the cloud

Have Developer Mode enabled: The last requirement is to have Developer Mode enabled on your device. This can be done by Navigating to Settings > Find your Build Number > Tap it 7 times until a popup appears

SlimLP ROM Android 5.1.1 update OnePlus One

  1. Download
  2. Download Android 5.1.1 Gapps
  3. Connect your OnePlus One to your computer using your USB cable
  4. Flash the SlimSaber SlimLP ROM .zip file to your OnePlus One internal storage
  5. Disconnect your OnePlus One and turn it off
  6. Boot into CWM Recovery mode
  7. Perform a full system wipe and cache partition (Also wipe Dalvik cache)  To do this, go to ‘advanced’ option and then click Wipe Dalvik Cache.
  8. Then choose the “Install .zip from SD Card”
  9. Chooses the file
  10. After it is done, choose the Google Apps (Gapps) .zip file and install them
  11. Once the ROM and Gapps installation completes, go to “+++++Go Back+++++” and select Reboot System Now