There seems to be a lot of confusion concerning how to flash, root, and update these new a/b devices, with a lot of adventurous users bootlooping or even bricking their devices. Thought it might help to provide some basic guidelines some of you might find useful. Not intended to be exhaustively inclusive...
1. Know what you are doing before you do it, not after. Ask before try.
2. Unless you are an expert, do not be first in line to try untested procedures. Have some patience and wait for the definitive guide.
3. Do not flash images from a different model device to yours.
4. Keep your current active slot on the same version of firmware as it is your fall back when things go wrong in the inactive slot. Simply put, flash new firmware to the inactive slot, otherwise you risk bootloops.
5. Only when you have successfully booted an updated firmware, then the inactive slot becomes your current active slot, and the now inactive slot becomes your backup of the previous version.
6. Do not reboot your device out of frustration unless you are sure the active slot has a uncorrupted current system boot image. Otherwise you risk the device not booting into system.
7. Do not relock your bootloader unless you have just flashed a complete stock firmware. Otherwise you risk bricking your device.
8. Do not mod beyond your skills until you have a custom recovery installed, such as TWRP, and an nandroid backup of a working system.
9. Do not update your system or Magisk without a nandroid backup to restore when things inevitably go wrong.
10. Do not flash or OTA update a ROM without first enabling USB Debugging for ADB and Fastboot access, plus creating a TWRP nandroid backup of your working system to restore when it goes wrong. Also, an ADB or Titanium backup of your apps and data, plus phone databases to restore if successful.
How to fix a bootloop or booting directly into recovery:
1. When you are stuck on the boot screen, you can turn off by holding the power button until it shuts down.
2. From phone off, press & hold Power + Volume Down button for a few seconds to boot your phone into bootloader mode.
3. Reflash a current system stock boot image to the active slot and reboot. You can test it first...
fastboot boot stockboot.img
4. If that doesn't work, see if you can go back to your previous system in the inactive slot. In bootloader mode...
fastboot set_active other
and reboot.
5. If all else fails and you do not have a nandroid backup to restore, flash-all stock firmware removing the “-w” from the script to preserve apps, settings, and data.
Helpful Guides:
Android Backup Types...
https://android.stackexchange.com/tags/backup/info/
A/B Seamless Updates & Commands...
https://www.xda-developers.com/how-...ess-updates-affect-custom-development-on-xda/
Magisk Docs...
https://topjohnwu.github.io/Magisk/
Magisk-MagiskHide Install & Troubleshooting Guide...
https://www.didgeridoohan.com/magisk/
Pixel Firmware Images...
https://developers.google.com/android/images
1. Know what you are doing before you do it, not after. Ask before try.
2. Unless you are an expert, do not be first in line to try untested procedures. Have some patience and wait for the definitive guide.
3. Do not flash images from a different model device to yours.
4. Keep your current active slot on the same version of firmware as it is your fall back when things go wrong in the inactive slot. Simply put, flash new firmware to the inactive slot, otherwise you risk bootloops.
5. Only when you have successfully booted an updated firmware, then the inactive slot becomes your current active slot, and the now inactive slot becomes your backup of the previous version.
6. Do not reboot your device out of frustration unless you are sure the active slot has a uncorrupted current system boot image. Otherwise you risk the device not booting into system.
7. Do not relock your bootloader unless you have just flashed a complete stock firmware. Otherwise you risk bricking your device.
8. Do not mod beyond your skills until you have a custom recovery installed, such as TWRP, and an nandroid backup of a working system.
9. Do not update your system or Magisk without a nandroid backup to restore when things inevitably go wrong.
10. Do not flash or OTA update a ROM without first enabling USB Debugging for ADB and Fastboot access, plus creating a TWRP nandroid backup of your working system to restore when it goes wrong. Also, an ADB or Titanium backup of your apps and data, plus phone databases to restore if successful.
How to fix a bootloop or booting directly into recovery:
1. When you are stuck on the boot screen, you can turn off by holding the power button until it shuts down.
2. From phone off, press & hold Power + Volume Down button for a few seconds to boot your phone into bootloader mode.
3. Reflash a current system stock boot image to the active slot and reboot. You can test it first...
fastboot boot stockboot.img
4. If that doesn't work, see if you can go back to your previous system in the inactive slot. In bootloader mode...
fastboot set_active other
and reboot.
5. If all else fails and you do not have a nandroid backup to restore, flash-all stock firmware removing the “-w” from the script to preserve apps, settings, and data.
Helpful Guides:
Android Backup Types...
https://android.stackexchange.com/tags/backup/info/
A/B Seamless Updates & Commands...
https://www.xda-developers.com/how-...ess-updates-affect-custom-development-on-xda/
Magisk Docs...
https://topjohnwu.github.io/Magisk/
Magisk-MagiskHide Install & Troubleshooting Guide...
https://www.didgeridoohan.com/magisk/
Pixel Firmware Images...
https://developers.google.com/android/images
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