How To Build CyanogenMod For Samsung Galaxy Note 4 T-Mobile ("trltetmo")

Introduction

These instructions will hopefully assist you to start with a stock Galaxy Note 4 T-Mobile, unlock the bootloader (if necessary), and then download the required tools as well as the very latest source code for CyanogenMod (based on Google’s Android operating system). Using these, you can build both CyanogenMod and CyanogenMod Recovery image from source code, and then install them both to your device.

It is difficult to say how much experience is necessary to follow these instructions. While this guide is certainly not for the very very very 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 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 Galaxy Note 4 T-Mobile
• A relatively recent computer (Linux, OS X, or Windows) with a reasonable amount of RAM and about 100 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 8 GB or more). Using SSDs results in considerably faster build times than traditional hard drives.
• A USB cable compatible with the Galaxy Note 4 T-Mobile (typically micro USB, but older devices may use mini USB or have a proprietary cable)
• A decent internet connection & 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 for “change directory”, the concept of directory hierarchies, that in Linux they are separated by /, etc.

If you are not accustomed to using Linux-- this is an excellent chance to learn. It’s free-- just download and run a virtual machine (VM) such as Virtualbox, then install a Linux distribution such as Ubuntu (AOSP vets Ubuntu as well). Any recent 64-bit version should work great, but the latest is recommended.

Using a VM allows Linux to run as a guest inside your host computer-- a computer in a computer, if you will. If you hate Linux for whatever reason, you can always just uninstall and delete the whole thing. (There are plenty of places to find instructions for setting up Virtualbox with Ubuntu, so I’ll leave it to you to do that.)

So let’s begin!

Build CyanogenMod and CyanogenMod Recovery

Prepare the Build Environment

Install the SDK

If you have not previously installed adb and fastboot, install the Android SDK. "SDK" stands for Software Developer Kit, and it includes useful tools that you can use to flash software, look at the system logs in real time, grab screenshots, and more-- all from your computer.

Install the Build Packages

Several "build packages" are needed to build CyanogenMod. You can install these using the package manager of your choice.

For both 32-bit & 64-bit systems, you'll need:

bc bison build-essential curl flex git gnupg gperf libesd0-dev liblz4-tool libncurses5-dev libsdl1.2-dev libwxgtk2.8-dev libxml2 libxml2-utils lzop maven openjdk-7-jdk pngcrush schedtool squashfs-tools xsltproc zip zlib1g-dev

In addition to the above, for 64-bit systems, get these:

g++-multilib gcc-multilib lib32ncurses5-dev lib32readline-gplv2-dev lib32z1-dev

For Ubuntu 15.10 (wily) and newer, substitute:

• lib32readline-gplv2-dev → lib32readline6-dev

For Ubuntu 16.04 (xenial) and newer, substitute (additionally see java notes below):

• libwxgtk2.8-dev → libwxgtk3.0-dev
• openjdk-7-jdk → openjdk-8-jdk

Java versions: Different versions of CyanogenMod require different versions of the JDK (Java Development Kit):

• CyanogenMod 7 - 9: Sun/Oracle Java SE 1.6
• CyanogenMod 10.1: Sun/Oracle Java SE 1.6 or 1.7
• CyanogenMod 10.2 - 11.0: Sun/Oracle Java SE 1.6 or 1.7 (OpenJDK 1.7 works fine, but the build system will display a warning)
• CyanogenMod 12.0 - 13.0: OpenJDK 1.7 (see note about OpenJDK 1.8 below)
• CyanogenMod 14.1: OpenJDK 1.8

Ubuntu 16.04 (Xenial Xerus) or newer and OpenJDK: Since OpenJDK 1.7 was removed from the official Ubuntu repositories, you have a couple options:

1. Obtain OpenJDK 1.7 from the openjdk-r PPA
2. Enable experimental OpenJDK 1.8 support in CyanogenMod 13.0 (not available in earlier version). To enable OpenJDK 1.8 support, add this line to your $HOME/.bashrc file: export EXPERIMENTAL_USE_JAVA8=true.

Also see http://source.android.com/source/initializing.html which lists needed packages.

Create the directories

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

To create them:

$ mkdir -p ~/bin
$ mkdir -p ~/android/system

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

Initialize the CyanogenMod source repository

Enter the following to initialize the repository:

Note: Make sure the cm branch entered here is the one you wish to build and is supported on your device.

$ cd ~/android/system/
$ repo init -u https://github.com/CyanogenMod/android.git -b cm-13.0

Download the source code

To start the download of all the source code to your computer:

$ repo sync

The CM 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. -c will ask repo to pull in only the current branch, instead of the entire CM history.

Prepare to wait a long time while the source code downloads.

Get prebuilt apps (CM11 and below)

Next,

$ cd ~/android/system/vendor/cm

then enter:

$ ./get-prebuilts

You won't see any confirmation- just another prompt. But this should cause some prebuilt apps to be loaded and installed into the source code. Once completed, this does not need to be done again.

Prepare the device-specific code

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

$ source build/envsetup.sh
$ breakfast trltetmo

This will download the device specific configuration and kernel source for your device. An alternative to using the breakfast command is to build your own local manifest. To do this, you will need to locate your device on CyanogenMod's GitHub and list all of the repositories defined in cm.dependencies in your local manifest.

Extract proprietary blobs

Now ensure that your Galaxy Note 4 T-Mobile is connected to your computer via the USB cable and that you are in the ~/android/system/device/samsung/trltetmo directory (you can cd ~/android/system/device/samsung/trltetmo if necessary). Then run the extract-files.sh script:

$ ./extract-files.sh

You should see the proprietary files (aka “blobs”) get pulled from the device and moved to the ~/android/system/vendor/samsung directory. If you see errors about adb being unable to pull the files, adb may not be in the path of execution. If this is the case, see the adb page for suggestions for dealing with "command not found" errors.

Turn on caching to speed up build

You can speed up subsequent builds by adding

export USE_CCACHE=1

to your ~/.bashrc file (what's a .bashrc file?). Then, specify the amount of disk space to dedicate to ccache by typing this from the top of your Android tree:

prebuilts/misc/linux-x86/ccache/ccache -M 50G

where 50G corresponds to 50GB of cache. This only needs to be run once and the setting will be remembered. Anywhere in the range of 25GB to 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. See more information about ccache on Google's android build environment initialization page.

Start the build

Time to start building! So now type:

$ croot
$ brunch trltetmo

The build should begin.

If the build breaks...

• If you experience this not-enough-memory-related error...

ERROR: signapk.jar failed: return code 1make: *** [out/target/product/trltetmo/cm_trltetmo-ota-eng.root.zip] Error 1

...you may want to make the following change to ~/android/system/build/tools/releasetools/common.py:

Search for instances of -Xmx2048m (it should appear either under OPTIONS.java_args or near usage of signapk.jar), and replace it with -Xmx1024m or -Xmx512m.

Then start the build again (with brunch).

• If you see a message about things suddenly being “killed” for no reason, your (virtual) machine may have run out of memory or storage space. Assign it more resources and try again.

Install the build

Assuming the build completed without error (it will be obvious when it finishes), type:

$ cd $OUT

in the same terminal window that you did the build. Here you’ll find all the files that were created. The stuff that will go in /system is in a folder called system. The stuff that will become your ramdisk is in a folder called root. And your kernel is called... kernel.

But that’s all just background info. The two files we are interested in are (1) recovery.img, which contains CyanogenMod Recovery, and (2) cm-13.0-20161224-UNOFFICIAL-trltetmo.zip, which is the CyanogenMod installation package.

Install CyanogenMod

Back to the $OUT directory on your computer-- you should see a file that looks something like:

cm-13.0-20161224-UNOFFICIAL-trltetmo.zip

Now you can flash the cm...zip file above as usual via recovery mode. Before doing so, now is a good time to make a backup of whatever installation is currently running on the device in case something goes wrong with the flash attempt. While CyanogenMod Recovery doesn't have a backup feature, there are other custom recoveries available that do. You can also use something like Titanium Backup (root required) as an alternative.

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.

Now that you've succeeded in building CyanogenMod for your device, here are some suggestions on what to do next.

Also, be sure to take a glance at the Dev Center on this wiki for all kinds of more detailed information about developer topics ranging from collecting logs, understanding what's in the source code directories, submitting your own contributions, porting CyanogenMod to new devices, and a lot more.

Congrats again!

To get assistance

• #cyanogenmod-dev - A helpful, real-time chat room (or “channel”) on Freenode IRC (Internet Relay Chat).