[OnePlus 3 & 3T Cross Device Development] TerrorApple:
Installation Tutorial

Installation Tutorial

Because so many have been asking for specific installation instructions I wrote some ;) I will be using a computer in the process. I find it's the easiest and fastest way for backups, restoring and copying the files to flash after wiping as I prefer to wipe internal storage too. If you don't have a computer or don't want to wipe internal storage, this is fine too of course and the tutorial includes the steps for you too.

Obviously there are many ways on how to backup / wipe / install. If your method works for you, great :) This is just an example on how it can be done. If you find any errors or have suggestions for improvements please do let me know.

If you don't have an unlocked bootloader yet (e.g. coming from stock OOS), check out this thread on how the unlock the bootloader and install TWRP: https://xdaforums.com/oneplus-3/how-to/oneplus-3-how-to-unlock-bootloader-t3398733 (the steps are identical for the OP3 and OP3T, just make sure to download the correct TWRP for your device). You can now continue with the main tutorial.

Let's go:

1. Backup everything you need, your system and data will be wiped! I recommend Titanium Backup for your important Apps (like Google Authenticator). Copy your files and backups to a computer or a cloud storage.

2. Download all the files you will need. Check out the list below. If you have a computer, store them there in a folder. If you don't, place the files on the internal storage of your device (everything else will be wiped!).

3. Flash the newest official TWRP for your device. This is important, older versions cannot decrypt your data partition and may throw Error 7 while flashing. Official TWRP 3.2.1-0 works fine. Using the official TWRP app from Play Store to update is the easiest: https://play.google.com/store/apps/details?id=me.twrp.twrpapp (assuming you have root - if you don't use the fastboot method from the "unlock bootloader"-thread I linked above)

4. Reboot to TWRP, easiest is via advanced reboot. Or you can reboot normally and press the volume buttons when you see the "your device is unlocked and cannot be trusted" screen. Select "recovery" here.

5. Optional but recommended: make a Nandroid backup! Select backup and tick everything besides Cache. Backup. If you have space issues, use the TWRP file manager to delete large files you can redownload anyway (Spotify music, Netflix series, movies etc.). For Spotify / Netflix etc. you can also boot back into your ROM and go to settings -> apps -> Spotify / Netflix -> delete data. Once your backup is finished, copy it to your computer (or upload to a cloud storage through your ROM).

6. Change your file system to ext4, in case it is F2FS. F2FS will cause problems with RR Oreo, so use ext4. Go to Wipe -> Advanced Wipe -> Repair or change file system. Make sure System, Data and Internal Storage are formatted to ext4. Don't format Internal Storage if you don't have a computer and are keeping files here to flash later!

7. If you have a computer: Wipe -> Advanced Wipe. Select everything except USB-OTG. Wipe. Now copy you files for flashing downloaded in step 2 from your computer to the device (if you have problems copying see the end of my post, Windows copying to Android can be a bit buggy)

If you don't have a computer: Wipe -> Perform a factory reset (this will not wipe internal storage and keep the files you downloaded for flashing in step 2)

8. Flash ("Install" in TWRP) all your files in this order. Don't reboot inbetween!

- Firmware

- ROM

- GApps (optional but recommended)

- Magisk (optional but recommended if you want root; Magisk passes SafetyNet)

- anything else you'd like to install (optional)

9. Reboot and login to your Google Account in setup to restore your Apps (select to apply backup on first setup). You can't do this later!

10. Restore all other data you backupped in step 1 (Titanium Backup, files etc.)

File List:

- Firmware (OP3) (download the latest Open Beta / OB for Oreo / 8.0 / 8.1): https://xdaforums.com/oneplus-3/how-to/radio-modem-collection-flashable-zips-t3468628 (direct link: https://jamal2367.com/downloads/?dir=OnePlus 3/Firmware + Modems/Android 8.0.0/Open Beta )

- Firmware (OP3T) (download the latest Open Beta / OB): https://xdaforums.com/oneplus-3t/how-to/firmware-beta-10-t3631166

- ROM (see first post of this thread)

- GApps (see first post of this thread - but any OpenGapps for Oreo ARM64 will do) - I recommend Nano (includes everything that can't be installed from Play Store, but not overloaded with stuff you can install manually from Play Store afterwards anyway)

- Magisk (get both latest ZIP and Manager apk): https://xdaforums.com/apps/magisk/official-magisk-v7-universal-systemless-t3473445

Copying Files from Windows to Android / TWRP workaround:

0. Assuming you are in TWRP

1. Install http://xdaforums.com/showthread.php?t=2588979 (in case you don't have adb installed on your computer yet)

2. Browse to your folder where you have stored the files you want to transfer

3. Shift + Rightclick -> Open PowerShell here / Open Commandpromt here

4. If you opened PowerShell (ignore this step if you opened Commandpromt): type "cmd" and hit enter

5. type "adb devices" and hit enter. You should see your device here (weird name). If not, your adb setup is broken. If the command is not recognised, the installer from step 1 may have failed

6. type "adb push FILENAME". Replace filename with the file you want to transfer. It is enough to type the first few letters and use the tab key to autocomplete.

7. repeat step 6 for all your files

8. flash the files you just transferred in TWRP

You can also directly flash from your computer, this is called sideload:

0. Assuming you are in TWRP

1. TWRP: tap advanced -> ADB sideload. Stay in this window

2. follow steps 1 to 5 above

3. type "adb sideload FILENAME". Replace filename with the file you want to flash (stick to order in step 8 of the main tutorial above!). It is enough to type the first few letters and use the tab key to autocomplete.

4. repeat step 3 for all your files - you can now reboot your phone. Flashing in TWRP not necessary!

Enjoy RR Oreo folks :)