[Google Pixel 3a ROMs, Kernels, Recoveries, & Other] ZVNexus:
Team Win Recovery Project 3.x, or TWRP3 for short, is a custom recovery built with ease of use and customization in mind. Its 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.

[I]#include <std_disclaimer.h>

/*
* Your warranty is not void.
*
* We are not responsible for bricked devices, dead SD cards,
* thermonuclear war, or you getting fired because the alarm app failed. Please
* do some research if you have any concerns about features included in this recovery
* before flashing it! YOU are choosing to make these modifications, and if
* you point the finger at us for messing up your device, we will laugh at you.
*
*/[/I]

Pixel devices have 2 "slots" for ROMs / firmware. TWRP will detect whichever slot is currently active and use that slot for backup AND restore. There are buttons on the reboot page and under backup -> options to change slots. Changing the active slot will cause TWRP to switch which slot that TWRP is backing up or restoring. You can make a backup of slot A, switch to B, then restore the backup which will restore the backup of A to slot B. Changing the slot in TWRP also tells the bootloader to boot that slot.

Note: Please be aware that you cannot install this without a kernel with LZMA compression support, I believe most ROMs have included my commit for this so you should be good for all custom ROMs and kernels (Not Android 10), if not please file a request to the maintainer.

To follow up, please be aware that TWRP is currently not compatible with Android 10. If you would like to use TWRP you will need to go back to Android 9. If you would like more information you can read at the link here.

Installation:

If you already have TWRP installed: Download the latest zip and install the zip using TWRP.

If you do not already have TWRP installed: Download both the img and the zip. You will need to have fastboot binaries and the correct drivers installed. Power off your device completely. Hold volume down and turn on the device. Your device should now be in the bootloader. Connect the device to your PC. Open a command window and run the following command from the proper location:

fastboot boot path/to/twrp.img

This will temporarily boot TWRP on your device. Use ADB or MTP to transfer the zip onto your device.

Go to install and browse to the zip and install the zip. The zip will install TWRP to both boot slots. Installing TWRP at this time will remove root if you are currently rooted.

If you accidently flash TWRP to your device using fastboot instead of temporarily booting the image, you will need to download the latest factory image for your device and reflash the boot image.

Changelog:

[BETA]

3.3.1-0: Initial release for Pixel 3A devices

3.3.1-1: Fixed having to manually change slots before rebooting.

3.3.1-2: Updated to July blobs!

3.3.1-3: Can now install TWRP to boot image. ADB, MTP, LOGD, Repack Tools and Logcat have all been removed to save the necessary space for this to work. You can grab stuff while in the OS, then flash it in TWRP (Keep in mind I have only tested this on stock as of now, feel free to test it on whatever ROM you use. It should work, but let me know if it doesn't).

3.3.1-4: Changed back to LZMA compression, also added back all the features besides ADB/Logcat. As long as your kernel supports LZMA you will be able to take advantage of installing it permanently without having to worry about space restrictions.

3.3.1-5:

Add persist entry to fstab

* To allow TWRP to store a backup settings file on /persist

and also to be used as QCOM time fix source during early boot.

Revert "Don't include logcat."

Revert "Don't include repack tools."

3.3.1-6:

Revert "Revert "Don't include repack tools.""

Add haptics firmware.

* This obviously on it's own isn't enough to get haptics working for the 3A in TWRP, but its a start.

Don't include a precompiled update_engine_sideload

* This should fix the issue of flashing officials for StatiXOS

[STABLE]

3.3.1-0: Initial official release!

Download:

https://twrp.me/google/googlepixel3a.html

XDA:DevDB Information

TWRP, Tool/Utility for the Google Pixel 3a

Contributors

ZVNexus, janjan

Source Code: https://github.com/TeamWin/android_device_google_bonito

Version Information

Status: Beta

Current Stable Version: 3.3.1-0

Stable Release Date: 2019-07-17

Current Beta Version: 3.3.1-6

Beta Release Date: 2019-06-27

Created 2019-06-27

Last Updated 2019-11-15