Bootloader freedom
Your new Nexus 6P or Nexus 5X
comes from the factory with a locked bootloader. While unlocking it is
trivial, it's important to remember that an unlocked bootloader is very
unsecure, and makes your personal data more vulnerable should someone
get your phone in their hands. If you're not the type of person who
wants to flash ROMs or system images or the like, it's probably best to
leave it locked. That's for you to decide.
Should you decide to unlock your bootloader, remember that doing so
will erase all the user data on your phone and return it to the
out-of-box state. Still with us? Cool. Here's how to do it.
You'll need a working installation of fastboot on your computer. Yes,
you need a computer to unlock the bootloader. We recommend that you install the Android SDK
and the official Google USB driver if you're using Windows, but there
are toolkits and bundles available if you'd rather go that way.
We're going to go with the premise that you've downloaded and installed
the Android SDK for your computing platform, and any needed drivers for
Windows computers.
Next, you'll need a suitable cable.
In this case, suitable means one end needs to be USB Type-A to plug
into your computer, and the other needs to be USB Type-C to plug into
your phone. For the Nexus 6P and 5X, we recommend you use the one that
came in the box.
Now you need to give permission for the bootloader to be unlocked. And
to make things easy, enable USB debugging on your phone. Go to settings,
About phone and find the entry labeled build number. Tap it five times,
read the pop up telling you that you're a developer now, then go back
to the main settings page. Near the bottom, you'll see a new entry
labeled Developer options. Tap it to get in there, and toggle the switch
to allow OEM unlocking, then enable USB debugging.
Now connect all the things together, and fire up the command line on
your Windows computer or a terminal program on your Mac or Linux
computer. Make sure your phone is unlocked and the screen is on, because
you'll be asked to authorize the computer and give it permissions to
communicate with your Nexus 6P over a wire. Once that's done and sorted,
it's time to do some typing.
On your computer, at the command prompt type:
adb devic
If everything is good, you'll see the phone's serial number in your
command line window. If not, you probably have a PATH issue. See the
tutorial about setting up the SDK for help if you're using a full SDK
installation, or ask in the developers support thread if you're using
some sort of toolkit. As a workaround, you can navigate to the folder
with the adb and fastboot executable files and work from there. If you
do this on a Mac or Linux computer, remember your dot and slash: "./adb
devices" for example.
Once you have things sorted, it's time to reboot to the bootloader:
adb reboot-bootloader
When you get to this stage, you will need to use fastboot to
communicate instead of adb. If you're working out of the folder where
the fastboot command is located, remember that dot and slash if you're
using a Mac or Linux computer. Try this command to see if everything is
working:
fastboot devices
See the serial number like we did with the adb command? If so, you're
good to go. If not, you need to troubleshoot. If you're using Windows
and having issues, chances are it's the driver. In any case, hit the
forums and work out why things aren't communicating if you need to.
Up until now, things are the same here as they have always been with
Nexus phones. But the command to actually unlock the bootloader has
changed. When you're ready, at your command line, type:
fastboot flashing unlock
Remember — this will erase everything on your phone and restore it to the way it came out of the box.
You'll need to confirm this action on your phone's screen, using the
volume and power keys. Follow the instructions on your screen.
Let it do it's thing, and when it's done send one more command to make things final:
fastboot reboot
After recovery erases everything and you've booted back to Android
(at the device setup screen) you can unplug your cable and use your
phone normally.
If you ever decide to relock your bootloader, you can do so with this command:
fastboot flashing lock
Remember, if you need to unlock your bootloader again, things will get erased again.
That's it. Your bootloader is now unlocked, and you can flash both
official and unofficial firmware to your Nexus. In fact, you'll be
reminded that your bootloader unlocked each and every time you start
your phone. Stay safe, and choose wisely!
