Android is the most widely used mobile operating system in the world. And the best part, it’s completely open source, which in layman terms, means that the Source Code, the actual program is available openly for everyone to download, customize and build their own ROMs.
There are lots of custom Android Distributions available out there, with the popular ones being CyanogenMod ,SlimROM , Paranoid Android, AOKP , Liquid Smooth , MIUI , Xylon, Ice Cold Jelly etc.
For today’s guide, we will compile CyanogenMod 10.2, the most popular Android aftermarket ROM. The procedure is 99% same for all custom ROMs out there, so this guide can be used as a reference to compile other ROMs too.
- An Android Phone with readily available Kernel and Device Source, already rooted and with a custom recovery installed.
- 64 bit Linux Distribution (We prefer Ubuntu).
- At Least 100GB free on your Hard Disk.
- Working knowledge of Linux Terminal Commands.
- Reasonably fast internet connection.
Point to note: 64 bit Linux OS is a must, and it must be a native installation, not a Virtual Machine.
Set Up Your Build Machine
1. Install the Linux OS of your choice: 64 bit version, according to the official instructions. (The guide will assume that we are running Ubuntu 13.04). Keep a partition of at least 100GB with 16GB Swap Partition.
2. Install the following list of packages: Open Terminal app, and type ‘sudo apt-get install
git-core gnupg flex bison python rar original-awk gawk p7zip-full gperf libsdl1.2-dev libesd0-dev libwxgtk2.6-dev squashfs-tools build-essential zip curl libncurses5-dev zlib1g-dev pngcrush schedtool libc6-dev x11proto-core-dev libx11-dev libg11-mesa-dev mingw32 tofrodos python-markdown libxml2-utils g++-multilib lib32z1-dev ia32-libs lib32ncurses5-dev lib32readline-gplv2-dev gcc-multilib g++-multilib xsltproc
3. Install Java JDK 1.6 for Linux 64-bit: File name should be jdk-6u##-linux-x64.bin, ## are version numbers. Move the downloaded package to your home directory. Open Terminal app and run the following set of commands:
sudo apt-get purge openjdk-\* icedtea-\* icedtea6-\* sudo mkdir –p /opt/java/64/ sudo cp jdk-6u##-linux-x64.bin /opt/java/64 sudo su – cd /opt/java/64 chmod a+x jdk-6u##-linux-x64.bin ./jdk-6u##-linux-x64.bin exit
Now, we must add JDK Path to .bashrc
sudo gedit ~/.bashrc
Add these lines in the ending of the text file
# Java Path export JAVA_HOME=/opt/java/64/jdk1.6.0_## export PATH=$PATH:$JAVA_HOME/bin
4. Install Android SDK: Open Terminal App
cd ~ mkdir android &amp;amp;&amp;amp; cd android mkdir sdk
Download Android SDK from http://developer.android.com/sdk/index.html. Extract the package contents to ~/android/sdk We must add Android SDK path to .bashrc
sudo gedit ~/.bashrc
Add these lines to the ending of the text file:
# Android SDK Path export PATH=$PATH:~/android/sdk export PATH=$PATH:~/android/sdk/platform-tools export PATH=$PATH:~/android/sdk/tools
Now, install Android SDK Tools by typing
5. Set up your github account and remote repo: You can skip this step if CyanogenMod supports your phone officially. Go to github.com, and make an account for yourself. For this guide, I am considering your username as ‘user’.
Visit ‘github.com/CyanogenMod/android’, press Fork. The remote manifest will be forked, and available in your personal repo.
Now, go to ‘github.com/user/android’. Open the file default.xml, press Edit. Find this line:
&amp;lt;project path=&amp;quot;android&amp;quot; name=&amp;quot;CyanogenMod/android&amp;quot; /&amp;gt;
And replace this with
&amp;lt;project path=&amp;quot;android&amp;quot; name=&amp;quot;user/android&amp;quot; /&amp;gt;
I am considering your device’s kernel source, device source and vendor libs for Android 4.3 to be at
github.com/user2/kernel_source github.com/user2/device_source github.com/user2/device-common_source github.com/user2/vendor
I am assuming the branch to be named ‘jb4.3’. You can find the exact name in the actual repo. Then, at the end of the file, add these lines, modifying them according to your device’s source code.
&amp;lt;project path=&amp;quot;kernel/your_company/your_device&amp;quot; name=&amp;quot;user2/kernel_source&amp;quot; remote=&amp;quot;github&amp;quot; revision=&amp;quot;jb4.3&amp;quot; /&amp;gt; &amp;lt;project path=&amp;quot;device/your_company/your_device&amp;quot; name=&amp;quot;user2/device_source&amp;quot; remote=&amp;quot;github&amp;quot; revision=&amp;quot;jb4.3&amp;quot; /&amp;gt; &amp;lt;project path=&amp;quot;device/your_company/your_device-common&amp;quot; name=&amp;quot;user2/device-common_source&amp;quot; remote=&amp;quot;github&amp;quot; revision=&amp;quot;jb4.3&amp;quot; /&amp;gt; &amp;lt;project path=&amp;quot;vendor/your_company&amp;quot; name=&amp;quot;user2/vendor&amp;quot; remote=&amp;quot;github&amp;quot; revision=&amp;quot;jb4.3&amp;quot; /&amp;gt;
Commit your changes. Your remote manifest is ready to be deployed.
6. Install Repo Command: Open Terminal and type
cd ~ mkdir ~/bin curl &amp;gt; ~/bin/repo chmod a+x ~/bin/repo
We must add Repo path to .bashrc
sudo gedit ~/.bashrc
Add this line to the end of the text file
7. Fetch the ROM source code: Open Terminal and type
mkdir ~/android/cm cd ~/android/cm
If you needed Step 5 , then type
repo init –u git://github.com/user/android.git –b cm-10.2
If your device supports CyanogenMod 10.2 officially, then type
repo init –u git://github.com/CyanogenMod/android.git –b cm-10.2
repo sync –j16
Go grab a coffee, or a meal, it’s gonna take a long time. The source code is well over 10GB in size, so it will take quite some time.
8. Set up the Device Specific Stuff: If your device supports CyanogenMod 10.2 officially, then open Terminal and type
cd ~/android/cm . build/envsetup.sh &amp;amp;&amp;amp; breakfast &amp;lt;device_codename&amp;gt;
It will take some time, the device source is about 3GB in size. Then, you need to have official CM10.2 installed on your phone, connect it to your PC in USB Debugging mode, and run the following commands:
adb root cd ~/android/cm/device/&amp;lt;your_company&amp;gt;/&amp;lt;your_device&amp;gt;/ ./extract-files.sh
If your device does not support CyanogenMod 10.2 officially, then you got nothing to do in this step, the sources are already waiting for you.
9. Download Prebuilt Stuff and set up Toolchain: Open Terminal and type
cd ~/android/cm/vendor/cm sh ./get-prebuilts
Now, we must add the Toolchain PATH to ./bashrc
cd ~/android/cm sudo gedit ~/.bashrc
Add these lines to the end of the text file
# Android Toolchain export ARCH=arm export CCOMPILE=$CROSS_COMPILE export CROSS_COMPILE=arm-eabi- export PATH=$PATH:~/android/cm/prebuilt/linux-x86/toolchain/arm-eabi-4.4.3/bin
10. Build your ROM: So, everything is all right and ready. It’s time to build the ROM. Open Terminal and type
cd ~/android/cm . build/envsetup.sh brunch &amp;lt;device_codename&amp;gt;
Time to go take a nap. It will take a zillion years to build the ROM on an average computer. Well, that was exaggeration, but on my home PC (Core i5 2nd gen with 8GB RAM), it takes over 3 hours to build from scratch. Hopefully, there will be no errors, and the build will complete fine. You will get the output package in
It’s time to install your newly compiled ROM on your phone. Download Google Apps package from “www.goo.im/gapps” for the appropriate Android version. Put both those packages in your phone, and flash them in recovery mode. Voila, your own compiled ROM is now running your device.
Well, so you learnt how to compile a ROM. So, now what?
Update Your Source ROM
To fetch new source code updates to your locally downloaded source code, open Terminal and type
cd ~/android/cm repo sync –j16
To build your ROM, after updating source code, open terminal and type
cd ~/android/cm make installclean find ./out/ -name ‘build.prop’ | xargsrm find ./out/ -name ‘cm_&amp;lt;your_device&amp;gt;-target_files-eng.*.zip’ | xargsrm . build/envsetup.sh brunch &amp;lt;your_device&amp;gt;
Since you are not re-building from scratch, but re-building as it is, it will take significantly less time, only about 15-30 mins in most cases. You should sync your local source every week or so, to keep your local source fresh.
Clean Your Working Directory
To clean your working directory completely (read: return your source folder to stock condition), open Terminal and type the following commands.
cd ~/android/cm make installclean make clobber
Bear in mind, that after running these commands, all your output data will be removed, so the next build will take 3-4 hours again, as everything is re-built from scratch. If your Hard Disk partition is small, say around 100GB, you should clean your working directory about once every 4 builds, or else, you will run out of Hard Disk space.
Speed up your build by CCACHE
Building a ROM takes a lot of time. But the time can be cut down by about 30-45% by using CCACHE. CCACHE stands for compiler cache, it caches the compilation output from your earlier builds, so that it can be re-used in later builds.
Note that CCACHE needs a lot of space on your Hard Disk for caching the content, so its recommended if and only if your Hard Disk partition is somewhere in the vicinity of 200GB or higher. To set up CCACHE, open Terminal and type:
cd ~/android/cm export USE_CCACHE=1 export CACHE_DIR=~/.ccache prebuilts/misc/linux-x86/ccache/ccache –M 50G
You can change the maximum size allocation to CCACHE from 50GB to whatever you want, but a minimum of around 30GB should be used for good results.
Fetch Commits from Other ROMs
You can cherry-pick features from other ROMs source code. Say for example, I want to pick Feature A , with commit ID “12345” from repository “github.com/user/reporepo”.
You navigate to the package in your local source code and run these in Terminal.
cd ~/&amp;lt;path_to_reporepo_packages&amp;gt; git fetch git cherry-pick 12345
Source Code Links of Famous Android Custom ROM Distributions
CyanogenMod – https://github.com/CyanogenMod
SlimROM – https://github.com/SlimRoms
ParanoidAndroid – https://github.com/ParanoidAndroid
AOKP – https://github.com/AOKP
LiquidSmooth – https://github.com/liquidsmooth
Xylon ROM –
Ice Cold Jelly – https://github.com/IceColdJelly
So, there you go guys, a simple, straightforward guide to compile virtually any Android AOSP based ROM in 10 simple steps. While my guide focuses on CyanogenMod, you can compile pretty much every AOSP ROM out there, by just modifying the repository links. Or, you can just pick features, commit them, modify stuff and create your own personalized ROM, maybe share your ROM online too?