Android One 2nd Gen (seed)

LineageOS ROM Google Android One 2nd Gen (seed)

Table of contents

Install LineageOS on seed

Basic requirements

  1. Make sure your computer has adb and fastboot. Setup instructions can be found here.
  2. Enable USB debugging on your device.

Unlocking the bootloader

  1. Enable OEM unlock in the Developer options under device Settings, if present.

  2. Connect the device to your PC via USB.
  3. On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type: 
    adb reboot bootloader

    You can also boot into fastboot mode via a key combination:

    • With the device powered off, hold Volume Down + Power.
  4. Once the device is in fastboot mode, verify your PC finds it by typing: 
    fastboot devices

  5. Now type the following command to unlock the bootloader:

    fastboot oem unlock
  6. If the device doesn’t automatically reboot, reboot it. It should now be unlocked.
  7. Since the device resets completely, you will need to re-enable USB debugging to continue.

Installing a custom recovery using fastboot

  1. Download a custom recovery – you can download TWRP. Simply download the latest recovery file, named something like twrp-x.x.x-x-seed.img.

  2. Connect your device to your PC via USB.
  3. On the computer, open a command prompt (on Windows) or terminal (on Linux or macOS) window, and type: 
    adb reboot bootloader

    You can also boot into fastboot mode via a key combination:

    • With the device powered off, hold Volume Down + Power.
  4. Once the device is in fastboot mode, verify your PC finds it by typing: 
    fastboot devices
  5. Flash recovery onto your device: 
    fastboot flash recovery <recovery_filename>.img
  6. Now reboot into recovery to verify the installation:
    • With the device powered off, hold Volume Up + Power.

    Alternatively, on some devices and recoveries you can use fastboot to boot directly into the freshly flashed or any other desired recovery:

    fastboot boot <recovery_filename>.img

Installing LineageOS from recovery

  1. Build a LineageOS installation package.
    • Optionally, download additional application packages such as Google Apps (use the arm architecture).
  2. If you are not in recovery, reboot into recovery:
    • With the device powered off, hold Volume Up + Power.
  3. Now tap Wipe.
  4. Now tap Format Data and continue with the formatting process. This will remove encryption and delete all files stored in the internal storage.
  5. Return to the previous menu and tap Advanced Wipe, then select the Cache and System partitions and then Swipe to Wipe.
  6. Sideload the LineageOS .zip package:
    • On the device, select “Advanced”, “ADB Sideload”, then swipe to begin sideload.
    • On the host machine, sideload the package using: adb sideload filename.zip

  7. (Optionally): If you want to install any additional add-ons, repeat the sideload steps above for those packages in sequence.

  8. (Optionally): Root your device by installing LineageOS’ AddonSU, (use the arm package) or by using any other method you prefer.
  9. Once you have installed everything successfully, run ‘adb reboot’.

Update to a newer build of the same LineageOS version on seed

Updating your device

Using the LineageOS Updater app

  1. Open Settings, navigate to “System”, then “Updater”.
  2. Click the Refresh Icon in the top right corner.
  3. Choose which update you’d like and press “Download”.
  4. When the download completes, click “Install”. Your device will reboot to recovery and install the update, then reboot to the updated installation.

From your PC via the push_update script (Linux/macOS only)

  1. Make sure your computer has working adb. Setup instructions can be found here.
  2. Enable USB debugging on your device. Additionally, open Settings, then “System”, then “Developer Options”, and then either check “Rooted Debugging” (LineageOS 17.1 or above) or select “Root Access Options”, then “ADB Only”.
  3. Run adb root
  4. Run wget https://raw.githubusercontent.com/LineageOS/android_packages_apps_Updater/lineage-16.0/push-update.sh && chmod +x push-update.sh
  5. Run: ./push-update.sh /path/to/zip
  6. Open Settings, navigate to “System”, then “Updater”. Then proceed to click “Install” on the newly pushed update to commence installation. Your device will reboot to recovery and install the update, then reboot to the updated installation.

Sideloading from Recovery

  1. Make sure your computer has working adb. Setup instructions can be found here.
  2. Enable USB debugging on your device. Additionally, open Settings, then “System”, then “Developer Options”, and then either check “Rooted Debugging” (LineageOS 17.1 or above) or select “Root Access Options”, then “ADB Only”.
  3. Run: adb reboot sideload

  4. Run: adb sideload /path/to/zip

  5. Run: adb reboot

Upgrade to a higher version of LineageOS (e.g. lineage-15.1 -> lineage-16.0) on seed

Manually upgrading LineageOS

The updater app does not support upgrades from one version of LineageOS to another, and will block installation to any update for a different version. Upgrading manually requires similar steps to installing LineageOS for the first time.

  1. Build a LineageOS install package.
    • Optionally, download additional application packages such as Google Apps (use the arm architecture).
  2. Make sure your computer has working adb. Setup instructions can be found here.
  3. Enable USB debugging on your device. Additionally, open Settings, then “System”, then “Developer Options”, then select “Root Access Options”, and finally “ADB Only”. Now, run adb root’
  4. Run adb reboot sideload.
  5. Run adb sideload /path/to/zip (inserting the path to your LineageOS package).
  6. (Optionally): If you want to install any additional add-ons, click Advanced, then ADB Sideload, then swipe to begin sideload, then adb sideload /path/to/zip those packages in sequence.
  7. (Optionally): Root your device by installing LineageOS’ AddonSU, (use the arm package) or by using any other method you prefer.
  8. Once you have installed everything successfully, run adb reboot.

Build for seed

Introduction

These instructions will hopefully assist you to start with a stock Google Android One 2nd Gen, unlock the bootloader (if necessary), and then download
the required tools as well as the very latest source code for LineageOS (based on Google’s Android operating system) for your device. Using these, you can build both
a LineageOS installation zip and a LineageOS Recovery image and install them on your device.

It is difficult to say how much experience is necessary to follow these instructions. While this guide is certainly not for the extremely uninitiated,
these steps shouldn’t require a PhD in software development either. Some readers will have no difficulty and breeze through the steps easily.
Others may struggle over the most basic operation. Because people’s experiences, backgrounds, and intuitions differ, it may be a good idea to read through
just to ascertain whether you feel comfortable or are getting over your head.

Remember, you assume all risk of trying this, but you will reap the rewards! It’s pretty satisfying to boot into a fresh operating system you baked at home :).
And once you’re an Android-building ninja, there will be no more need to wait for “nightly” builds from anyone. You will have at your fingertips the skills to
build a full operating system from code and install it to a running device, whenever you want. Where you go from there– maybe you’ll add a feature, fix a bug, add a translation,
or use what you’ve learned to build a new app or port to a new device– or maybe you’ll never build again– it’s all really up to you.

What you’ll need

  • A Google Android One 2nd Gen.
  • A relatively recent 64-bit computer (Linux, macOS, or Windows) with a reasonable amount of RAM and about 200 GB of free storage (more if you enable ccache
    or build for multiple devices). The less RAM you have, the longer the build will take. Aim for 16 GB RAM or more, enabling ZRAM can be helpful. Using SSDs results in considerably faster
    build times than traditional hard drives.
  • A USB cable compatible with the Google Android One 2nd Gen.
  • A decent internet connection and reliable electricity. 🙂
  • Some familiarity with basic Android operation and terminology. It would help if you’ve installed custom roms on other devices and are familiar with recovery.
    It may also be useful to know some basic command line concepts such as cd, which stands for “change directory”, the concept of directory hierarchies, and that in Linux they are separated by /, etc.

Let’s begin!

Build LineageOS and LineageOS Recovery

Install the platform-tools

If you haven’t previously installed adb and fastboot, you can download them from Google.
Extract it running:

unzip platform-tools-latest-linux.zip -d ~

Now you have to add adb and fastboot to your PATH. Open ~/.profile and add the following:

# add Android SDK platform tools to path
if [ -d "$HOME/platform-tools" ] ; then
    PATH="$HOME/platform-tools:$PATH"
fi

Then, run source ~/.profile to update your environment.

Install the build packages

Several packages are needed to build LineageOS. You can install these using your distribution’s package manager.

To build LineageOS, you’ll need:

  • bc bison build-essential ccache curl flex g++-multilib gcc-multilib git gnupg gperf imagemagick
    lib32ncurses5-dev lib32readline-dev lib32z1-dev liblz4-tool libncurses5 libncurses5-dev
    libsdl1.2-dev libssl-dev libxml2 libxml2-utils lzop pngcrush rsync
    schedtool squashfs-tools xsltproc
    zip zlib1g-dev

For Ubuntu versions older than 20.04 (focal), install also:

  • libwxgtk3.0-dev

While for Ubuntu versions older than 16.04 (xenial), install:

  • libwxgtk2.8-dev

Java

Different versions of LineageOS require different JDK (Java Development Kit) versions.

  • LineageOS 16.0-17.1: OpenJDK 1.9 (included by default)
  • LineageOS 14.1-15.1: OpenJDK 1.8 (install openjdk-8-jdk)
  • LineageOS 11.0-13.0: OpenJDK 1.7 (install openjdk-7-jdk)*

* Ubuntu 16.04 and newer do not have OpenJDK 1.7 in the standard package repositories. See the Ask Ubuntu question “How do I install openjdk 7 on Ubuntu 16.04 or higher?”. Note that the suggestion to use PPA openjdk-r is outdated (the PPA has never updated their offering of openjdk-7-jdk, so it lacks security fixes); skip that answer even if it is the most upvoted.

Create the directories

You’ll need to set up some directories in your build environment.

To create them:

mkdir -p ~/bin
mkdir -p ~/android/lineage

The ~/bin directory will contain the git-repo tool (commonly named “repo”) and the ~/android/lineage directory will contain the source code of LineageOS.

Install the repo command

Enter the following to download the repo binary and make it executable (runnable):

curl https://storage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
chmod a+x ~/bin/repo

Put the ~/bin directory in your path of execution

In recent versions of Ubuntu, ~/bin should already be in your PATH. You can check this by opening ~/.profile with a text editor and verifying the following code exists (add it if it is missing):

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi

Then, run source ~/.profile to update your environment.

Configure git

Given that repo requires you to identify yourself to sync Android, run the following commands to configure your git identity:

git config --global user.email "[email protected]"
git config --global user.name "Your Name"

Initialize the LineageOS source repository

The following branches can be used to build for the Google Android One 2nd Gen:

  • cm-14.1

Enter the following to initialize the repository:

cd ~/android/lineage
repo init -u https://github.com/LineageOS/android.git -b cm-14.1

Download the source code

To start the download of the source code to your computer, type the following:

repo sync

The LineageOS manifests include a sensible default configuration for repo, which we strongly suggest you use (i.e. don’t add any options to sync).
For reference, our default values are -j 4 and -c. The -j 4 part means that there will be four simultaneous threads/connections. If you experience
problems syncing, you can lower this to -j 3 or -j 2. On the other hand, -c will ask repo to pull in only the current branch instead of all branches that are available on GitHub.

Prepare the device-specific code

After the source downloads, ensure you’re in the root of the source code (cd ~/android/lineage), then type:

source build/envsetup.sh
breakfast seed

This will download your device’s device specific configuration and
kernel.

Extract proprietary blobs

Now ensure your Android One 2nd Gen is connected to your computer via the USB cable, with ADB and root enabled, and that you are in the
~/android/lineage/device/google/seed folder. Then run the extract-files.sh script:

./extract-files.sh

The blobs should be pulled into the ~/android/lineage/vendor/google folder. If you see “command not found” errors, adb may
need to be placed in ~/bin.

Turn on caching to speed up build

Make use of ccache if you want to speed up subsequent builds by running:

export USE_CCACHE=1
export CCACHE_EXEC=/usr/bin/ccache

and adding that line to your ~/.bashrc file. Then, specify the maximum amount of disk space you want ccache to use by typing this:

ccache -M 50G

where 50G corresponds to 50GB of cache. This needs to be run once. Anywhere from 25GB-100GB will result in very noticeably increased build speeds
(for instance, a typical 1hr build time can be reduced to 20min). If you’re only building for one device, 25GB-50GB is fine. If you plan to build
for several devices that do not share the same kernel source, aim for 75GB-100GB. This space will be permanently occupied on your drive, so take this
into consideration.

You can also enable the optional ccache compression. While this may involve a slight performance slowdown, it increases the number of files that fit in the cache. To enable it, run:

ccache -o compression=true

Configure jack

Jack is the currently used Java toolchain for building LineageOS 14.1 and 15.1. It is known to run out of memory often if not configured correctly – a simple fix is to run this command:

export ANDROID_JACK_VM_ARGS="-Dfile.encoding=UTF-8 -XX:+TieredCompilation -Xmx4G"

Adding that command to your ~/.bashrc file will automatically configure Jack to allocate a sufficient amount of memory (in this case, 4GB).

Start the build

Time to start building! Now, type:

croot
brunch seed

The build should begin.

Install the build

Assuming the build completed without errors (it will be obvious when it finishes), type the following in the terminal window the build ran in:

cd $OUT

There you’ll find all the files that were created. The two files of more interest are:

  1. recovery.img, which is the LineageOS recovery image.

  2. lineage-14.1-20201116-UNOFFICIAL-seed.zip, which is the LineageOS
    installer package.

Success! So… what’s next?

You’ve done it! Welcome to the elite club of self-builders. You’ve built your operating system from scratch, from the ground up. You are the master/mistress of your domain… and
hopefully you’ve learned a bit on the way and had some fun too.

Content of this page is based on informations from github and LineageOS Wiki, under CC BY-SA 3.0 licence.