====== Android ======
This page introduce how you can download and compile the Android kernel for **ODROID-U3/X2**. 
To build the Android Kernel, we strongly recommend the **gcc version 4.4.1** .
===== Toolchain =====
Click one of the site to download toolchain to build Linux kernel.
  * [[http://www.mdrjr.net/odroid/toots/arm-2010q1.tar.xz|Download Linux Kernel Toolchain(arm-2010q1)]]
  * [[http://dn.odroid.com/toolchains/arm-2010q1.tar.xz|Download Linux Kernel Toolchain(arm-2010q1)]]
Once the download is done, extract the tarball to **/opt/toolchains/**.
<code>
$ sudo mkdir -p /opt/toolchains
$ unxz arm-2010q1.tar.xz
$ tar xvf arm-2010q1.tar
$ sudo mkdir /opt/toolchains
$ sudo mv arm-2010q1 /opt/toolchains/
</code>
In order to add the toolchain path to PATH, paste below lines to **$HOME/.bashrc**.
<code>
export PATH=$PATH:/home/odroid/adt-bundle-linux-x86_64-20140702/sdk/platform-tools:/opt/toolchains/arm-2010q1/bin
export ARCH=arm
export CROSS_COMPILE=arm-none-linux-gnueabi-
</code>
You can apply the change if you login again or import 
to apply this change, login again or evaluate **$HOME/.bashrc** with source command.
<code>
$ source ~/.bashrc
</code>
You can check if the toolchain installed above works properly while checking the version of toolchain. If you can find **(Sourcery G++ Lite 2010q1-202) 4.4.1** at the end of the line, the toolchain is well installed.
<code>
$ source ~/.bashrc
$ $ arm-none-linux-gnueabi-gcc --version
arm-none-linux-gnueabi-gcc (Sourcery G++ Lite 2010q1-202) 4.4.1
Copyright (C) 2009 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
</code>
===== Checkout =====
You can checkout **Kernel** source tree from **[[https://github.com/hardkernel/linux|Hardkernel's Github]]**, **Android platform** source tree from **[[https://github.com/hardkernel/android|Hardkernel's Github]]**. 
Please note that we distribute the Linux kernel in different branches for Android and other Linux distributions.

==== Android Kernel ====
<code>
$ git clone --depth 1 https://github.com/hardkernel/linux.git -b odroid-3.0.y-android
$ cd linux
</code>
==== Android Platform ====
== android-4.1.2 ==
<code>
$ mkdir <Android Platform Folder Name>
$ cd <Android Platform Folder Name>
$ repo init -u https://github.com/hardkernel/android.git -b 4412_4.1.2_master
$ repo sync
$ repo start 4412_4.1.2_master --all
</code>
== android-4.4.4 ==
<code>
$ mkdir <Android Platform Folder Name>
$ cd <Android Platform Folder Name>
$ repo init -u https://github.com/hardkernel/android.git -b 4412_4.4.4_master
$ repo sync
$ repo start 4412_4.4.4_master --all
</code>
==== ====
<WRAP  left round tip 70%>
  * Visit this link to install the repo.
[[http://source.android.com/source/downloading.html]]
</WRAP>




===== Compile =====
Before compiling, you must configure for **ODROID-U3** with following command.

==== Android Kernel ====
=== Android-4.1.2 ===
== ODROID-U2/U3 ==
<code>
$ make odroidu_android_422_defconfig
$ make
</code>
== ODROID-X2 ==
<code>
$ make odroidx2_android_422_defconfig
$ make
</code>



=== Android-4.4.4 ===
We've merged the Kernel source into the Android repo. Android build-script also includes the Kernel compile.

If you still want to compile only the kernel,
<code>
$ make odroidXX_android_442_defconfig
$ make
</code>
==== Android Platform ====
=== ODROID-U2/U3 ===
<code>
$ ./build_android.sh odroidu
</code>
=== ODROID-X2 ===
<code>
$ ./build_android.sh odroidx2
</code>
===== Installation =====
There are different instructions to install Linux kernel image for Android and Linux. Since Android loads both from a kernel partition, we have to use **fastboot** to install into the dedicated partition. Please refer the partition table from [[http://odroid.com/dokuwiki/doku.php?id=en:u3_partition_table|here]]. In contrast, Linux boots by the instructions described in **boot.ini** the 1st FAT partition.

This is the instruction to install kernel image, **zImage**, to the boot card.

<code>
$ sudo fastboot flash kernel <path/of/your/zImage>
</code>

This is to install android platform files, **system.img**, **userdata.img**, **cache.img**.

<code>
$ sudo fastboot flash system <path/of/your/system.img>
$ sudo fastboot flash userdata <path/of/your/userdata.img>
$ sudo fastboot flash cache <path/of/your/cache.img>
</code>

If you want to initialize the FAT partition, run this command.

<code>
$ sudo fatboot erase fat
</code>

[[http://codewalkerster.blogspot.kr/search?q=cross_compile]]