Install LineageOS on
OnePlus 9

Basic requirements

1. Read through the instructions at least once before actually following them, so as to avoid any problems due to any missed steps!
2. Make sure your computer has adb and fastboot. Setup instructions can be found here.
3. Enable USB debugging on your device.
4. Make sure that your model is actually listed in the “Supported models” section here (exact match required!)
5. Boot your device with the stock OS at least once and check every functionality.
   warning

   Warning: Make sure that you can send and receive SMS and place and receive calls (also via WiFi and LTE, if available), otherwise it won’t work on LineageOS either! Additionally, some devices require that VoLTE/VoWiFi be utilized once on stock to provision IMS.
6. LineageOS is provided as-is with no warranty. While we attempt to verify everything works you are installing this at your own risk!

Checking the correct firmware

Installation on your device requires a specific firmware version to be installed before you continue.

• Firmware refers to a device-specific set of images that are included in, and updated by the stock OS
• LineageOS builds for this device require an Android 13 version of the stock OS to be installed prior to following the installation guide
• Please ensure that you are checking the Android version, and not the vendor OS version
• Being on another custom ROM, including unofficial builds of the same version of LineageOS, does not ensure that this requirement has been fulfilled
• Please re-read this section as many times as necessary to fully understand the requirements

Failing to install the correct firmware version prior to installation may result in failure to install LineageOS, unexpected crashes post-installation, or permanent damage to your device!

Unlocking the bootloader

1. Enable OEM unlock in the Developer options under device Settings, if present.
2. Connect the device to your PC via USB.
3. On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type:

   adb -d reboot bootloader
   

   You can also boot into fastboot mode via a key combination:

   • With the device powered off, hold Volume Up + Volume Down + Power.
4. Once the device is in fastboot mode, verify your PC finds it by typing:

   fastboot devices
   

   If you don’t get any output or an error:

   • on Windows: make sure the device appears in the device manager without a triangle. Try other drivers until the command above works!
   • on Linux or macOS: If you see no permissions fastboot try running fastboot as root. When the output is empty, check your USB cable and port!
5. Now type the following command to unlock the bootloader:

   fastboot oem unlock
   

   info_outline

   Note: At this point, the device may display on-screen prompts which will require interaction to continue the process of unlocking the bootloader. Please take whatever actions the device asks you to in order to proceed.
6. If the device doesn’t automatically reboot, reboot it. It should now be unlocked.
7. Since the device resets completely, you will need to re-enable USB debugging to continue.

Flashing additional partitions

1. Download the following files from here.
   • dtbo.img
   • vbmeta.img
   • vendor_boot.img
2. Power off the device, and boot it into bootloader mode:
   • With the device powered off, hold Volume Up + Volume Down + Power.
3. Flash the downloaded image files to your device by typing:

   fastboot flash dtbo dtbo.img
   fastboot flash vbmeta vbmeta.img
   fastboot flash vendor_boot vendor_boot.img
   

Installing Lineage Recovery using fastboot

1. Download Lineage Recovery. Simply download the latest recovery file, named boot.img.
   warning

   Important: Other recoveries may not work for installation or updates. We strongly recommend to use the one linked above!
2. Flash recovery onto your device:

   fastboot flash boot boot.img
   

3. Now reboot into recovery to verify the installation.
   • Use the menu to navigate to and to select the Recovery option.
   info_outline

   Note: If your recovery does not show the LineageOS logo , you accidentally booted into the wrong recovery. Please start at the top of this section!

Installing LineageOS from recovery

1. Download the LineageOS zip file that you would like to install or build the package yourself.
2. If you are not in recovery, reboot into recovery:
   • With the device powered off, hold Volume Down + Power.
3. Now tap Factory Reset, then Format data / factory reset and continue with the formatting process. This will remove encryption and delete all files stored in the internal storage, as well as format your cache partition (if you have one).
4. Return to the main menu.
5. Sideload the LineageOS .zip package but do not reboot before you read/followed the rest of the instructions!
   • On the device, select “Apply Update”, then “Apply from ADB” to begin sideload.
   • On the host machine, sideload the package using: adb -d sideload filename.zip.
     check

     Tip: After the package is installed, recovery will inform you that reboot to recovery is required to install add-ons. In case you want to do that, please select “Yes,” otherwise “No”.
     check

     Tip: Normally, adb will report Total xfer: 1.00x, but in some cases, even if the process succeeds the output will stop at 47% and report adb: failed to read command: Success. In some cases it will report adb: failed to read command: No error or adb: failed to read command: Undefined error: 0 which is also fine.

Installing Add-Ons

1. Click Apply Update, then Apply from ADB, then adb -d sideload filename.zip for all desired packages in sequence.
   When presented with a screen that says Signature verification failed, click Yes. It is expected as add-ons aren’t signed with LineageOS’s official key!

All set!

Once you have installed everything successfully, you can now reboot your device into the OS for the first time!

• Click the back arrow in the top left of the screen, then “Reboot system now”.