[OnePlus 8T ROMs, Kernels, Recoveries, & Other Deve] Siddhant221:
Introduction:

Team Win Recovery Project or TWRP for short, is a custom recovery built with ease of use and customization in mind. We started from the ground up by taking AOSP recovery and loading it with the standard recovery options, then added a lot of our own features. It's a fully touch driven user interface , no more volume rocker or power buttons to mash. The GUI is also fully XML driven and completely theme-able. You can change just about every aspect of the look and feel.

Key Features:

Touchscreen driven with real buttons and drag-to-scroll

XML-based GUI that allows full customization of the layout true theming!

Settings are saved to the sdcard and persist through reboots

Ability to choose which partitions to back up and which to restore

Ability to choose to compress backups now with pigz (multi-core processor support for faster compression times)

Onscreen keyboard

Easy selection of internal/external storage

In addition to the above new features, TWRP features a scripting engine that allows an app to send commands to the recovery for the recovery to perform during startup. We call this scripting engine OpenRecoveryScript. This engine will be put to use immediately in the GooManager app. GooManager will be able to install recoveries automatically for most supported devices. The app will also let you choose to install multiple zips from within Android, wipe, and run a backup.

We are looking for other talented developers, themers, and device maintainers if they are interested in helping with a free, open source project.

Extra Fixes :-

Switched To 60 fps from 30 fps

Variant Script Fixed

Boot Control Revision from 1.1 to 1.2

Added Fix for Transferring File Above 4GB

Added Recovery Recovery Variant Of Fastboot Client

Working :-

Decryption

Fixed TWRP Boot up time

Backup/Restore Fixed :)

ADB/MTP

Flashing Rom

stock rom flashing is now supported

fixed fastbootd and adb sideload

Both Ext4 & Erofs is supported

BUGS :-

Other Bugs You tell me that !!!

Source Code:

GitHub - https://github.com/TeamWin/android_bootable_recovery

Gerrit Instance - http://gerrit.twrp.me

Hello, this is TWRP, for Oneplus 8T/9R

Installation:

# To temporarily boot it

fastboot boot <twrp_file_name>.img

# Since 8T/9R has a separate recovery partition, you can flash the recovery with

fastboot flash recovery <twrp_file_name>.img

Updating to a newer build:

Simply flash the latest TWRP installer zip from TWRP

OR

Flash the img from TWRP/fastboot

Send me a beer, if you think I deserve it: PayPal

Huge thanks to:

@bigbiff (For everything :D 🥰 )

@Lossyx

@osm0sis

@Nebrassy

@Qnorsten

@TheIncognito

for helping in making this recovery. Without these people, TWRP for this device would not have been possible. :D

Trees:

Device: https://github.com/ApexLegend007/twrp_device_oneplus_lemonades

Kernel: https://github.com/OnePlusOSS/android_kernel_oneplus_sm8250/tree/oneplus/sm8250_s_12.1

Download:

https://github.com/ApexLegend007/twrp_device_oneplus_lemonades/releases

Steps for backing up and restoring data in TWRP (Huge thanks to @BillGoss )

Flashing Rom :-

Make Sure That you have OOS 13 firmware On both slots before flashing rom based on OOS 13 firmware

Copy Rom.zip in your internal Storage Take Backup if you want to take backup Data Backup instruction are given below👇

After Flashing rom format data and reboot

(!!!!! Warning After flashing custom rom zip The recovery will get changed to AOSP recovery in the inactive slot in which rom got flashed if you want to flash twrp in that same recovery you can do it in bootloader mode!!!!!)

TWRP for data backup on custom ROMs:

Backup /data (copy the backup folder to PC if you will format /data).

Flash the ROM and boot it once to system.

Restore /data (copy the backup folder back from PC if you formatted in step 1) and boot into system.

If you find any issues like missing navigation bar or blank screen or something, just do a normal reboot again to system.

System Backup and Restore

The "system" partitions on the OnePlus 8T/9R are:

Boot

DTBO

Super which contains the logical system, system_ext, odm, product, and vendor partitions

VBMETA

VBMETA_SYSTEM

Just backup and restore these partitions.

Do NOT backup/restore any of the logical partitions individually.

Data Backup

Make sure USB debugging is enabled

You do NOT need to remove your password

In TWRP

Backup: Select only the Data partition.

Reboot System

Restore

Remove the current password before starting the restore process by Settings>Security & Lock Screen>Screen lock: Select Swipe (if prompted tap on "Yes, remove")

If you don't do this, the system will not reboot properly after restoring.

This will also remove your fingerprint data and your lockscreen (encryption) password (you won't be prompted for a password in TWRP or when you restart the system)

In TWRP

Wipe>Factory Reset

Reboot System (this will rebuild the data partition)

Back in TWRP

Restore: Select the backup you want to restore

Remove the SIM card. If you don't do this the system won't boot properly.

Reboot system, making sure the phone is not connected to a PC

Notes:

At this point the phone will take longer than usual to boot - that's normal

You will be presented with a blank screen

Connect the phone to a PC. You should be able to see the phone using adb devices

Disconnect the phone from the PC

Hold the Power button down and select Restart

In System

Settings>Security & Lock Screen>Screen lock: set your password

Insert the SIM card

Note: Your fingerprints will have been restored because the backup was taken with the password set.