[Nexus 5X General] SlimSnoopOS:
[size=+1]Frequently Asked Questions[/size]

1. How do I boot into the bootloader?

Power off your device. Once it's powered off hold power + volume down and the phone will boot into the bootloader. You can also use the following adb command:

adb reboot bootloader

You can also use an app called Quick Boot to boot into the bootloader directly from Android (root required).

2. How do I boot into recovery?

Boot into the bootloader (see above), use the volume keys to scroll through the options and use the power button to select the recovery mode option. You can also use the following adb command:

adb reboot recovery

You can also use an app called Quick Boot to boot into the recovery directly from Android (root required).

3. When issuing the fastboot flashing unlock command it doesn't work, I only get a list of possible commands. What's going on?

This is usually due to having an outdated adb/fastboot setup. If you installed adb/fastboot by any means other than via the Android SDK this is probably the cause. Visit the prerequisites section in the beginning of this guide to properly install adb/fastboot and ensure that it's up to date.

4. How do I take an OTA or update if I have root or other system modifications on the stock ROM?

You can't take an OTA update while you have root or any system modifications. You'd need to use fastboot to flash the system, boot, and recovery images. It's much easier to just flash the newer build with fastboot, see section 9 of this guide for full instructions.

5. Does taking an OTA update wipe my user data?

No, it doesn't.

6. Do I need to make an EFS backup?

Absolutely yes. An EFS backup is extremely important. If your EFS partition becomes corrupt, your IMEI will disappear and you will not be able to use the phone as a phone. Without a backup it can be extremely difficult (or impossible) to restore your EFS. See the next question for an EFS backup related issue and solution.

7. I have a bootloop after restoring my EFS backup in TWRP 3.0.2-1. What can I do?

TWRP 3.0.2-1 and 3.0.2-2 are the first official TWRP releases with Nougat 7.0 or newer compatibility. Unfortunately, there are separate bugs affecting TWRP 3.0.2-1 and 3.0.2-2. A member of the TWRP development team details these issues right here. This link redirects to a thread in the Nexus 6P forums but also applies to the Nexus 5X. Read the original post of that same thread to learn how to resolve this EFS restore bootloop. You must use ADB and the phone must be booted in TWRP to resolve this issue. These ADB commands work on the Nexus 5X and 6P.

8. Can I flash just the xxxxxx.img from the factory image without losing my data?

Flashing userdata.img will format your entire phone (personal data including SMS/MMS, pictures, downloaded files, etc). You can flash any combination of these partitions (boot, system, vendor, radio, or bootloader) and this will leave your personal data intact. However, any mods that you have installed into system, vendor, or boot will be overwritten and returned to the default factory image setup when you flash these partitions. Flashing recovery.img or a newer version of your custom recovery will replace your existing recovery.

9. After updating my ROM, I get this message on every boot: "There's an internal problem with your device. Contact your manufacturer."

This warning indicates a mismatched vendor and system partition. The vendor partition was formerly integrated in the system partition for previous Nexus devices but is now a separate partition that must be flashed for each Google security update. Download a factory image and update your vendor partition using fastboot so that it matches your rom's OS build and monthly security update. If you have a file explorer installed on your phone, you can determine which vendor.img is installed by navigating to /vendor/build.prop and clicking on the build.prop. The specific vendor installed will be a combination of six numbers and letters listed in all capitals (example: NMF26F) in the ro.vendor.build.fingerprint line. These will always match up with the factory image of the same Android build (six digit alphanumeric name) for this device.

Vendor.img is specific to each OTA and contains proprietary binaries for the phone that regularly receive updates to resolve security risks. If you are a custom rom user, make sure that you flash the vendor.img for the Google monthly security update that you are moving to. Be aware that sometimes AOSP roms utilize the AOSP master branch which has a newer Android build than the monthly security update for this device. You will still need to install that month's vendor.img.

The phone will fail to boot if you mismatch the vendor.img with a different Android version. For instance, a 6.0 Marshmallow vendor.img will not allow your phone to boot on 7.0 Nougat. The vendor.img is typically not included in the custom rom zip but is often available as a separate download in the custom rom thread's first post.