[Google Pixel 4 XL Guides, News, & Discussion] i5lee8bit:
READ THIS ENTIRE POST BEFORE PROCEEDING!

ADDITIONAL PRELIMINARY STEPS COMPARED TO PREVIOUS MONTHS - DO NOT SKIP!!!!:

A. Make sure all of your Magisk / EdXposed modules are updated for compatibility with R. For example:

* Magisk Module: Riru (Riru - Core) v21.3

* Magisk Module / EdXposed version: EdXposed v.0.5.0.6-android_r (4561) [this is a Canary build]

B. Recommend disabling any Magisk and/or Xposed modules that have not been tested with Android R.

C. Install latest Magisk Manager Canary build: https://raw.githubusercontent.com/topjohnwu/magisk_files/canary/app-debug.apk

D. Regular reboot the phone to make sure updates are applied before proceeding with the rest of the update process.

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EASY UPDATE / SEAMLESS KEEP-ROOT UPDATE PROCESS

(using a PC - a very intuitive, effective, and relatively safe method).

** You can only follow this guide verbatim if coming

EXACTLY from build "10.0.0 (QQ3A.200805.001, Aug 2020)"

. But the general idea is the same for other builds, you just need the correct files for your device.

coral-qq3a.200805.001-factory-dtbo.img: https://androidfilehost.com/?fid=8889791610682906527

coral-qq3a.200805.001-factory-boot.img: https://androidfilehost.com/?fid=8889791610682906525

September 2020 sideload OTA zip: https://dl.google.com/dl/android/aosp/coral-ota-rp1a.200720.009-b447daff.zip

DO NOT BOOT BACK INTO O/S UNTIL ALL STEPS ARE COMPLETED - THIS ENSURES EVERYTHING BOOTS BACK UP WITH MAGISK / EDXPOSED ALL RUNNING PROPERLY RIGHT AWAY

1. boot into bootloader

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** I was on custom kernel, so I needed to flash BOTH the stock boot and dtbo images

2. fastboot flash boot coral-qq3a.200805.001-factory-boot.img

3. fastboot flash dtbo coral-qq3a.200805.001-factory-dtbo.img

......* these steps to restore stock recovery; dtbo.img also necessary for some kernel installations.

......* won't hurt to flash both anyway, so if you're unsure, go ahead and do both.

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4. use volume keys to change selection to boot to Recovery Mode

......- when you reach the android symbol with No Command, hold power button, tap volume up, in case you've forgotten

5. choose option "Apply update from ADB"

6. adb sideload coral-ota-rp1a.200720.009-b447daff.zip

7. Once the OTA sideload is done, Reboot to bootloader (you'll also notice it's now on the other slot after OTA flashed)

8. fastboot flash boot coral-rp1a.200720.009-magisk_patched-c20424.img

9. done, start the phone

(Optional - Flash custom kernel. If you had a custom kernel, you need to re-flash it)

This is a 100% seamless update that requires no additional / re-setup of any of my Magisk or EdXposed setups. All of the factory files can be found here https://developers.google.com/android/images. boot.img and dtbo.img are in their corresponding full Factory Image zips, and the ota zip is under Full OTA Images.

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ADDITIONAL NOTES FROM [MENTION=1607642]sidhaarthm[/MENTION], WHO TESTED FOR ME - THERE'S SOME GOOD INFO HERE TO HELP PREP YOU BEFORE UPDATING YOUR PHONE:

Big thanks to [MENTION=1607642]sidhaarthm[/MENTION] for being an awesome and detailed tester!