I recently went through the process of installing Ubuntu Touch on my OnePlus 6T, and I thought some of the notes I took might be of help to someone else out there since the the current installation instructions do leave a few gaps, which perhaps are obvious if you are a bit more experienced but less so for noobs.

1. In order to get the UBPorts installer to recognise my device, I had I enable developer options (tap build number 4 times), select the USB connection option "Transfer files" from the notification drop down, AND then go enable USB debugging in developer options
2. Downgrade to OxygenOS 9 (i.e. Android 9) per instructions here: https://forum.xda-developers.com/t/guide-rollback-downgrade-from-oos-android-10-q-to-stable-9-pie.4000645/
   • Download the OnePlus 6T rollback zip
     MD5: 54ede6b7887f295cf8564904693cda34
   • Backup your phone if you so please
   • Copy the zip to the root of your internal storage
     • this wasn't as easy as I had hoped, because I had to find where the internal storage was actually located
     • I did this from the terminal on my laptop (Ubuntu)
       adb shell
cd storage
ls storage
# and then find the folder where you can see all of the directories, like Pictures
# you will probably need to recursively search under this folder, for me it was /storage/self/primary
# get out of the shell
exit
# finally, I pushed the zip file
adb push <zip_file> /storage/self/primary
   • On the phone, go to Settings > System > System Updates
   • Tap the gear icon top right, followed by 'Local upgrade'
   • Tap the "Fulldowngrade..." package you just downloaded
   • Read the warning and tap confirm
   • Wait for the progress bar
   • (the above steps probably could have also been done with a fresh flash, but this seemed easier)
3. Enable OEM Unlocking from Developer Options
4. Unlock the bootloader
   • Connect the device to your PC via USB.
   • On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type:
     adb reboot bootloader
     You can also boot into fastboot mode via a key combination: With the device powered off, hold Volume Up + Volume Down + Power.
   • 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 try running fastboot as root. When the output is empty, check your USB cable and port!
   • Now type the following command to unlock the bootloader:
     fastboot oem unlock
     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 to proceed. In my case, this involved selecting "Unlock Bootloader" with the Volume Down button and then Power Button to confirm
   • If the device doesn’t automatically reboot, reboot it. It should now be unlocked.
   • Since the device resets completely, you will need to re-enable USB debugging to continue, and remember to set the USB connection option from the notification menu to "File Transfer"
5. Check for any upgrades on the phone: Settings > System > System Updates
6. Run UB Ports Installer and let it do its thing

At the moment, it appears that the 6T isn't able to power down or restart smoothly (issue here). You will need to long press power button and volume up (and I do mean long!!! > 10 seconds). This caught me out when I was asked to reboot when putting in my SIM card.

From my preliminary searching of these forums, I get the sense that bluetooth is a bit of a fraught subject when it comes to Ubuntu Touch. Nevertheless, I want to see what my options are for getting my headset (Sony WH-1000XM3) to play audio from my OP6T.

At the moment, the UT side says that it is connected to the headphones, but I don't get the usual "Bluetooth Connected" notification from the headphones themselves. Upon trying to play some audio from the phone, it just plays out of the phone speakers, and not the headphone as desired.

This sounds similar to a problem on the Pixel 3a.

I know it says on the OP6/6T device page that bluetooth "works" so I am curious if any others are having similar issues?

Regardless of that, what are my options for trouble shooting?

I have attempted a restart of the bluetooth service:

sudo service bluetooth restart

But that just hangs and I need to restart the device. Also tried this:

rfkill block bluetooth && rfkill unblock bluetooth

But that also didn't resolve it.

bluetoothctl has also been mentioned in a few posts, and it looks like quite a powerful tool, but I don't have much experience with it. Any pointers?

I recently went through the process of installing Ubuntu Touch on my OnePlus 6T, and I thought some of the notes I took might be of help to someone else out there since the the current installation instructions do leave a few gaps, which perhaps are obvious if you are a bit more experienced but less so for noobs.

1. In order to get the UBPorts installer to recognise my device, I had I enable developer options (tap build number 4 times), select the USB connection option "Transfer files" from the notification drop down, AND then go enable USB debugging in developer options
2. Downgrade to OxygenOS 9 (i.e. Android 9) per instructions here: https://forum.xda-developers.com/t/guide-rollback-downgrade-from-oos-android-10-q-to-stable-9-pie.4000645/
   • Download the OnePlus 6T rollback zip
     MD5: 54ede6b7887f295cf8564904693cda34
   • Backup your phone if you so please
   • Copy the zip to the root of your internal storage
     • this wasn't as easy as I had hoped, because I had to find where the internal storage was actually located
     • I did this from the terminal on my laptop (Ubuntu)
       adb shell
cd storage
ls storage
# and then find the folder where you can see all of the directories, like Pictures
# you will probably need to recursively search under this folder, for me it was /storage/self/primary
# get out of the shell
exit
# finally, I pushed the zip file
adb push <zip_file> /storage/self/primary
   • On the phone, go to Settings > System > System Updates
   • Tap the gear icon top right, followed by 'Local upgrade'
   • Tap the "Fulldowngrade..." package you just downloaded
   • Read the warning and tap confirm
   • Wait for the progress bar
   • (the above steps probably could have also been done with a fresh flash, but this seemed easier)
3. Enable OEM Unlocking from Developer Options
4. Unlock the bootloader
   • Connect the device to your PC via USB.
   • On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type:
     adb reboot bootloader
     You can also boot into fastboot mode via a key combination: With the device powered off, hold Volume Up + Volume Down + Power.
   • 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 try running fastboot as root. When the output is empty, check your USB cable and port!
   • Now type the following command to unlock the bootloader:
     fastboot oem unlock
     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 to proceed. In my case, this involved selecting "Unlock Bootloader" with the Volume Down button and then Power Button to confirm
   • If the device doesn’t automatically reboot, reboot it. It should now be unlocked.
   • Since the device resets completely, you will need to re-enable USB debugging to continue, and remember to set the USB connection option from the notification menu to "File Transfer"
5. Check for any upgrades on the phone: Settings > System > System Updates
6. Run UB Ports Installer and let it do its thing

At the moment, it appears that the 6T isn't able to power down or restart smoothly (issue here). You will need to long press power button and volume up (and I do mean long!!! > 10 seconds). This caught me out when I was asked to reboot when putting in my SIM card.