How to manually update your Nexus

How to install Android 5.0 Lollipop on a Nexus 5 - Nexus, the line of Android devices developed in partnership between Google and different hardware manufacturers, is a program that allows developers to get their hands on a stock Android experience. It can help them develop applications for the platform quicker and easier than if they were using a device with a manufacturer skin onboard, and that's a good thing. But no matter whether a developer or average consumer buys a Nexus, either has the benefit of sideloading software updates from Google directly.

When Google works on updates to Android, it's building them to work specifically on Nexus devices. This means when Google releases an update to Android itself, it will come quickly to the supported Nexus devices instead of having to be modified to run on devices from other manufacturers. Among Nexus updates there are fast and slow(er) ways to get the update onto your phone or tablet — we're going to show you the fast way.

Before we go into the steps of sideloading Android updates to Nexus devices, it is strongly recommended that you have previous knowledge of working with the Android SDK (software development kit) and Terminal (OS X or Linux) or Command Prompt (Windows), as it is possible to harm your device if something were to go wrong in the following process.

If you need to download the Android SDK you can grab it from the Android Development website and follow their instructions on how to install it correctly. For the following process all you will need is the adb and fastboot files which are located in the Platform Tools folder.

Additionally, all the following commands are written as they would be in Terminal on a Linux or OS X platform. If you are following this guide and using a Windows machine, you will not need to use the "./" seen in the guide.

Enable developer settings and USB debugging

1. Go to your Nexus' Settings and scroll down to About Phone/Tablet
2. Tap on the Build number seven times until the dialog box says you are now a developer
3. Go back to the Settings menu and you should find a new option called Developer options. Click into the Developer options
4. Make sure that the developer options are turned on and that USB debugging is checked on
5. If you're upgrading a device running Lolipop already, make sure Enable OEM unlock is checked
6. Plug your Nexus device into your computer and click "ok" on the dialog box asking you to Allow USB debugging while connected to the computer. You can also select to always allow access on that computer

If done correctly, this will be everything you will need to do on your phone or tablet for the moment.

Unlocking your device

Now that you can connect to your Nexus device from your computer it's time to unlock your bootloader. To do this you must first boot into your bootloader. You can either manually turn off your phone or tablet and hold down the power button and the volume down button to enter your device's Bootloader Menu or you can enter the following commands into your terminal or command prompt.

Run the following command to make sure your device is properly connected to your computer. If it returns a string of characters it means that you are all set to start updating your device.

./adb devices

Now to enter into the Bootloader menu just run the following command.

./adb reboot bootloader

At the bottom of the screen there will be several things listed including the lock state of the device. This should say locked unless you have unlocked your bootloader in the past and never went back and locked it again.

Now to unlock your bootloader, which is required only when flashing a stock firmware image (not sideloading and update, which we'll get to soon), you must enter the below commands. Remember that when unlocking your Nexus' bootloader it will factory reset your device, so you will lose everything stored on it. If you have not yet backed up anything important on your device you can hit the power button while Start is highlighted in the Bootloader menu and this will boot you back into your device like normal. Now back to unlocking your bootloader.

./fastboot oem unlock

A dialog will appear on the device asking if you are sure about unlocking. Again this will factory reset your device, so if you want to back out of the process you just need to select no with the power button. If you are ready to unlock your bootloader you press the volume up button and then the power button to confirm that you wish to unlock your bootloader.

./fastboot reboot-bootloader

It is recommended to reboot the bootloader just to give itself a check to make sure everything is working correctly before moving onto the next step.

Flashing the Stock Nexus firmware image

Now that your bootloader is unlocked, it's time to flash the new firmware onto your Nexus device. To find the Nexus system images, head on over to the Nexus Factory Images page, find your Nexus device, and download the latest firmware available for it. It is easiest to then uncompress the file in the Platform Tools folder where the adb and fastboot files are so that you do have to type the path to the different files when flashing the firmware.

To begin, make sure you are still in the bootloader menu on your device and double check that your bootloader is in fact unlocked. If it is not unlocked the following commands will not do anything to your device.

Now it is time to flash the brand new bootloader with the following command.

./fastboot flash bootloader [bootloader file].img

You will not see anything on the screen of your device but there should be a dialog in your terminal or command prompt. When it is done flashing the bootloader you should reboot back into the bootloader as to make sure everything is still working correctly.

./fastboot reboot-bootloader

Next you flash the updated radios. This step is only necessary if you are updating the firmware of your Nexus phone or tablet that has cellular radios built into it.

./fastboot flash radio [radio file].img

./fastboot reboot-bootloader

Finally, it's time to flash the actual system image to your phone or tablet.

./fastboot -w update [image file].zip

When this is done, your Nexus will restart itself and boot up normally. As this process clears all data from your device, it will take slightly longer for your device to boot up for the first time. Once you have been greeted with the device setup walkthrough process, you know you have successfully flashed a new version of the firmware onto your Nexus.

If you do not want to enter the commands manually there are scripts included inside the compressed folder containing the system image that will do most but not all of the heavy lifting for you. The flash-all script files will automate the flashing of the bootloader, radios (if needed), and the system image. The problem with this process is that you must first make sure that your Nexus is in the bootloader menu and its bootloader must be unlocked before starting the script. Of course if these are not already done the script will fail to run and nothing will happen.

Flashing an OTA update image

When it comes to getting official Android updates, Nexus devices almost always win the race but that does not mean the updates roll out fast enough for Nexus owners. With every update there are two different types of files that become available for the different Nexus devices — the factory image that is a clean, fresh build of Android, and the OTA (over the air) update file that is sent to all the different Nexus phones and tablets on the market.

Once the OTAs start rolling out to consumers it is very common for someone to find the file's download path and pull the update .zip file. These can be found almost immediately online. Once you have the OTA file we recommend you backup your device's data just in case something goes wrong in the update process, but this process will generally not wipe your device unless done incorrectly.

Just as is the case with the factory image update, put the OTA file in the Platform Tools directory to simplify the process of sending the file to your phone.

First, make sure that your computer is communicating correctly with your Nexus phone or tablet. As long as your device's serial number comes back as a connected device you are ready to begin updating your device.

./adb devices

Next, put your device into the bootloader menu by either the following command or by holding down the power button and the volume down button while your Nexus is turned off.

./adb reboot bootloader

Now use the volume down button twice until you have scrolled to Recovery mode, and press the power button to select it. It will look like your Nexus is restarting itself but an image of an Android with a red exclamation mark over it will appear. Next hold down the power button and press the volume up button, and you will be in recovery mode.

Now that you are in the Android system recovery, use the volume down button to highlight apply update from ADB and press the power button to select it. The text on your Nexus' screen will now say that you can send the OTA to the device using adb.

./adb sideload [OTA file].zip

In your terminal or command prompt you will see dialog that shows you the progress of transferring the update to your phone or tablet and once it has been completely transferred you can read what is happening with the update live on screen. Again, once the process is done your Nexus device will restart itself and attempt to boot normally. You have successfully updated your Nexus!

Getting the newest software updates on your Nexus device is easy to do but understandably difficult the first time. Once you've gone through this process multiple times it will become second nature to you, so don't be discouraged. Luckily Nexus devices are extremely easy to get back into working order if something gets installed wrong or flashed incorrectly — so don't be alarmed if you've pressed the wrong button.

Source : androidcentral