The purpose
I will manually apply an OTA image to a Pixel.
(Simply put, I will be reinstalling the Android system that Google periodically sends to smartphones.)
Before trying this, I’ve also summarized the points I was curious about.
Caution
If you are performing a manual OTA image update, please be sure to back up your data and proceed at your own risk.
My concerns before starting
Can an OTA update be used for a downgrade?
The old OTA could not be applied.
Do user data and apps get erased when an OTA is applied?
While it does not appear to be deleted, please create a backup and proceed at your own discretion.
Is there a difference between applying an OTA update and flashing a factory image?
They are different.
With a factory image, you can downgrade the OS, but this will erase all data.
After a downgrade, the OS version won’t automatically revert to the latest version; the update will be listed as pending in system updates.
I also feel this method carries higher risks. (Though I’ve linked the official documentation below, the web tool didn’t work for me, and it was less clear and more nerve-wracking than an OTA installation.)
Please see the following page for instructions on how to apply a factory image.
When should an OTA image be applied?
So, when do you apply the OTA image? Apparently, it’s when the automatic OTA update fails. You could also try it as a last resort if your OS becomes unstable after an OTA has already been applied.
Steps
Preparations
ADB
You’ll need to install ADB. (I didn’t have to do this since it was automatically installed when I set up Android Studio.)
Add ADB to your system’s PATH.
USB connection
Connect the target Pixel and PC via USB and enable USB debugging in the Developer options.
Please refer to the following page for instructions on how to access the Developer options.
Downloading OTA Data
From the page below, download the OTA you’d like to use. Just a heads-up: it’s different for each model, so be careful.
Please run the following command after you download the file.
certutil -hashfile DownloadedFilePath SHA256The hash value calculated with SHA256 will be displayed.
Check if the first 8 characters of the filename (before the extension) match the first 8 characters of the hash. If they do not match, the file is corrupted and you should download it again.
The example below shows a red box, which confirms that the two values are the same.
Check for OTA updates.
Check for any pending OTA updates by navigating to Settings → System → Software updates → System updates.
Apply
Please execute the following command from the command prompt.
adb reboot recovery
Restart the device, and when “No Command” appears, press and hold the power button, then press the volume up button.
A menu will appear. Use the volume buttons to select “Apply update from ADB,” and press the power button to execute it.
Run the following command:
adb devices
Ensure the device status is “sideload” in the output below.
Apply the downloaded OTA with the following command:
adb sideload FileName
Once the process is complete, select Reboot system now and restart to finish.
Reference
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