What is Droidian?
Droidian is a Linux distribution for Android Phones based on Mobian, and therefore supports all Debian applications. It runs on a large majority of Android 9 devices. If a device has been ported to Ubuntu Touch and is android 9 or 10, it is likely possible to run Droidian.
Dependencies: Fastboot and ADB (On Arch these can be found in the android-tools package)
Downgrading to Android 9
Since the OnePlus 6T currently has a Halium build based on Android 9, we need to make sure our device is running Android 9 before Droidian can be installed.
This can be done by flashing OOS 9 to the phone using TWRP or MSM Download Tool.
If you have Android 9 already installed, skip to “Preparing files for droidian”.
TWRP Method
Firstly, download the OOS 9 zip from:
Also, download TWRP 3.5.2 for your respective device. You can use 3.6 instead for android 11.
Once these are saved, you can load your device into fastboot mode. On the OnePlus 6 this can be done by holding POWER + VOL UP. On the OnePlus 6T this can be done by holding VOL UP + VOL DOWN + POWER, hold these until you see fastboot mode appear.
Connect the phone to your machine with a USB cable.
Next, we can boot TWRP 3.5.2:
sudo fastboot boot twrp-3.5.2_9-0-[device].img
From TWRP, select Advanced, then Sideload. Then run the command:
sudo adb sideload OnePlus6Oxygen_22_OTA_034_all_1909112343_dd26.zip
(Change the filename depending on which is required for your device)
Select reboot from TWRP, then Bootloader.
Once fastboot mode loads once again, we should have OOS 9 installed to our currently booted slot, which means we are ready to install Droidian!
MSM Download Tool Method
Preparing files required for Droidian
First we need to download a few things. TWRP 3.3.1, the droidian zips and our boot image.
TWRP
Follow Droidian upstream docs!
We used to have to manually flash images, but Droidian now have a native installer which does the job for us. https://devices.droidian.org/#/devices/enchilada