[Google Pixel 2 XL Guides, News, & Discussion] beartek:
OEM unlocking greyed out

Unlocking the bootloader Does not work with a pixel 2xl purchased from Google Store :crying:

OEM unlocking is greyed out in Developer Options

Unlocking the bootloader

WARNING:

This WILL wipe your entire phone. Please make copies or backups of any important data. This can also go wrong rendering your device inoperable. Proceed with caution.

On your phone, open Settings, navigate to "System" then "About phone", and tap on the build number 7 times.

Go one menu up, click on "Developer options", and turn on USB debugging and OEM unlocking.

In your terminal, type the following command:

adb reboot bootloader

Next, decide if you want to do a standard unlock or critical unlock. A critical unlock allows you to directly flash bootloader files, otherwise you will get an error when you try to do so.

Depending on what you decided in the previous step, run the following commands:

fastboot flashing unlock

(OPTIONAL)

fastboot flashing unlock_critical

Follow the prompts on your device then reboot!

Flashing factory images

NOTE #1:

You CANNOT downgrade factory images. Google has prevented users from doing so to keep them safe from vulernabilities that were patched. You should only upgrade or reinstall the current image.

NOTE #2:

If you have mounted /system as rw at any point (like in TWRP), you must upgrade using the factory image method. OTAs will fail because they cannot verify the integrity of the disk since its verity data has been changed.

Updating to a new release (factory image):

Download the latest factory image from Google's website.

Reboot into the bootloader:

adb reboot bootloader

Unzip the factory image.

Inside you will see a bootloader image, a radio image, an image zip file, and a couple of flash scripts.

If you are on Windows, open the "flash-all.bat" file in a text editor. If you are on Mac or Linux, open the "flash-all.sh" instead.

Remove the "-w" flag before the fastboot command towards the end of the file. This will prevent fastboot from formatting your device.

Run the flash all script! Open a command prompt, navigate to the folder with the script, and run one of the following commands:

Windows:

flash-all

Mac/Linux:

./flash-all.sh

Reboot once it is finished!

Updating to a new release (OTA zip):

Download the latest OTA zip from Google's website

Reboot into recovery:

adb reboot recovery

Hold down the power button and push volume up

Select "Apply update from ADB"

Run the following command from the folder containing the OTA zip:

adb sideload <zip_name>.zip

Reboot once it is finished!

Clean flashing a factory image (wipe everything):

Download the latest factory image from Google's website

Reboot into the bootloader:

adb reboot bootloader

Unzip the factory image.

Run the flash all script! Open a command prompt, navigate to the folder with the script, and run one of the following commands:

Windows:

flash-all

Mac/Linux:

./flash-all.sh

Reboot once it is finished!

Rooting with Magisk

Download the Magisk Manager from the official thread and install it.

Grab a boot image to patch (either the one from the latest factory image or a custom kernel one) and push it to your device:

adb push <path_to_file> /sdcard/Download

Open Magisk Manager and click the Install button.

Click "Install" at the first prompt then choose "Patch Boot Image File". A file manager will pop up.

Select the boot image you want to patch and let Magisk Manager patch it.

Pull it off your device:

adb pull /sdcard/MagiskManager/patched_boot.img

Reboot into the bootloader:

adb reboot bootloader

Flash the boot image and reboot.

fastboot flash boot patched_boot.img
fastboot reboot

Open Magisk Manager and you should be rooted!

Closing statements

If there are any procedures you would like to see added (like flashing a custom kernel or booting TWRP), I am happy to add them if requested. Also, when requesting help, please be as specific as possible where you get confused. I want this guide to be clear as possible.[/QUOTE]