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 page.title=Initializing a Build Environment
 @jd:body

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 <div id="qv-wrapper">
   <div id="qv">
     <h2>In this document</h2>
     <ol id="auto-toc">
     </ol>
   </div>
 </div>

 <p>This section describes how to set up your local work environment to build
 the Android source files. You will need to use Linux or Mac OS. Building under
 Windows is not currently supported.</p>
 <p>For an overview of the entire code-review and code-update process, see <a
 href="life-of-a-patch.html">Life of a Patch</a>.</p>
 <h2 id="choosing-a-branch">Choosing a Branch</h2>
 <p>Some of the requirements for your build environment are determined by which
 version of the source code you plan to compile. See
 <a href="build-numbers.html">Build Numbers</a> for a full listing of branches you may
 choose from. You may also choose to download and build the latest source code
 (called <code>master</code>), in which case you will simply omit the branch specification
 when you initialize the repository.</p>
 <p>Once you have selected a branch, follow the appropriate instructions below to
 set up your build environment.</p>
 <h2 id="setting-up-a-linux-build-environment">Setting up a Linux build environment</h2>
 <p>These instructions apply to all branches, including <code>master</code>.</p>
 <p>The Android build is routinely tested in house on recent versions of
 Ubuntu LTS (14.04), but most distributions should have the required
 build tools available. Reports of successes or failures on other
 distributions are welcome.</p>
 <p>For Gingerbread (2.3.x) and newer versions, including the <code>master</code>
 branch, a 64-bit environment is required. Older versions can be
 compiled on 32-bit systems.</p>
 <p><strong>Note</strong>: See the <a href="building.html">Downloading and
 Building</a> page for the list of hardware and software requirements. Then
 follow the detailed instructions for Ubuntu and Mac OS below.</p>

 <h3 id="installing-the-jdk">Installing the JDK</h3>
 <p>The <code>master</code> branch of Android in the <a
 href="https://android.googlesource.com/">Android Open Source Project (AOSP)</a>
 requires Java 7. On Ubuntu, use <a href="http://openjdk.java.net/install/">OpenJDK</a>.</p>
 <p>Java 7: For the latest version of Android</p>
 <pre><code>$ sudo apt-get update
 $ sudo apt-get install openjdk-7-jdk
 </code></pre>

 <p>Optionally, update the default Java version by running:</p>
 <pre><code>$ sudo update-alternatives --config java
 $ sudo update-alternatives --config javac
 </code></pre>

 <p>If you encounter version errors for Java, set its
 path as described in the <a href="building-running.html#wrong-java-version">Wrong
 Java Version</a> section.</p>

 <p>To develop older versions of Android, download and install the corresponding version of the <a
 href="http://www.oracle.com/technetwork/java/javase/archive-139210.html">Java JDK</a>:<br/>
 Java 6: for Gingerbread through KitKat<br/>
 Java 5: for Cupcake through Froyo</p>

 <p><strong>Note</strong>: The <code>lunch</code> command in the build step will ensure that the Sun JDK is
 used instead of any previously installed JDK.</p>

 <h3 id="installing-required-packages-ubuntu-1404">Installing required packages (Ubuntu 14.04)</h3>
 <p>You will need a 64-bit version of Ubuntu. Ubuntu 14.04 is recommended.</p>
 <pre><code>$ sudo apt-get install bison g++-multilib git gperf libxml2-utils make zlib1g-dev:i386 zip</code></pre>

 <h3 id="installing-required-packages-ubuntu-1204">Installing required packages (Ubuntu 12.04)</h3>
 <p>You may use Ubuntu 12.04 to build older versions of Android. Version 12.04 is not supported on master or recent releases.</p>
 <pre><code>$ sudo apt-get install git gnupg flex bison gperf build-essential \
   zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \
   libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \
   libgl1-mesa-dev g++-multilib mingw32 tofrodos \
   python-markdown libxml2-utils xsltproc zlib1g-dev:i386
 $ sudo ln -s /usr/lib/i386-linux-gnu/mesa/libGL.so.1 /usr/lib/i386-linux-gnu/libGL.so
 </code></pre>

 <h3 id="installing-required-packages-ubuntu-1004-1110">Installing required packages (Ubuntu 10.04 -- 11.10)</h3>
 <p>Building on Ubuntu 10.04-11.10 is no longer supported, but may be useful for building older
 releases of AOSP.</p>
 <pre><code>$ sudo apt-get install git gnupg flex bison gperf build-essential \
   zip curl zlib1g-dev libc6-dev lib32ncurses5-dev ia32-libs \
   x11proto-core-dev libx11-dev lib32readline5-dev lib32z-dev \
   libgl1-mesa-dev g++-multilib mingw32 tofrodos python-markdown \
   libxml2-utils xsltproc
 </code></pre>
 <p>On Ubuntu 10.10:</p>
 <pre><code>$ sudo ln -s /usr/lib32/mesa/libGL.so.1 /usr/lib32/mesa/libGL.so
 </code></pre>
 <p>On Ubuntu 11.10:</p>
 <pre><code>$ sudo apt-get install libx11-dev:i386
 </code></pre>
 <h3 id="configuring-usb-access">Configuring USB Access</h3>
 <p>Under GNU/Linux systems (and specifically under Ubuntu systems),
 regular users can't directly access USB devices by default. The
 system needs to be configured to allow such access.</p>
 <p>The recommended approach is to create a file
 <code>/etc/udev/rules.d/51-android.rules</code> (as the root user) and to copy
 the following lines in it. <code>&lt;username&gt;</code> must be replaced by the
 actual username of the user who is authorized to access the phones
 over USB.</p>
 <pre><code># adb protocol on passion (Nexus One)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e12", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on passion (Nexus One)
 SUBSYSTEM=="usb", ATTR{idVendor}=="0bb4", ATTR{idProduct}=="0fff", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on crespo/crespo4g (Nexus S)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e22", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on crespo/crespo4g (Nexus S)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e20", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on stingray/wingray (Xoom)
 SUBSYSTEM=="usb", ATTR{idVendor}=="22b8", ATTR{idProduct}=="70a9", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on stingray/wingray (Xoom)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="708c", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on maguro/toro (Galaxy Nexus)
 SUBSYSTEM=="usb", ATTR{idVendor}=="04e8", ATTR{idProduct}=="6860", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on maguro/toro (Galaxy Nexus)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e30", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on panda (PandaBoard)
 SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d101", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on panda (PandaBoard ES)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="d002", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on panda (PandaBoard)
 SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d022", MODE="0600", OWNER="&lt;username&gt;"
 # usbboot protocol on panda (PandaBoard)
 SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d00f", MODE="0600", OWNER="&lt;username&gt;"
 # usbboot protocol on panda (PandaBoard ES)
 SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d010", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on grouper/tilapia (Nexus 7)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e42", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on grouper/tilapia (Nexus 7)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e40", MODE="0600", OWNER="&lt;username&gt;"
 # adb protocol on manta (Nexus 10)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4ee2", MODE="0600", OWNER="&lt;username&gt;"
 # fastboot protocol on manta (Nexus 10)
 SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4ee0", MODE="0600", OWNER="&lt;username&gt;"
 </code></pre>
 <p>Those new rules take effect the next time a device is plugged in.
 It might therefore be necessary to unplug the device and plug it
 back into the computer.</p>
 <p>This is known to work on both Ubuntu Hardy Heron (8.04.x LTS) and
 Lucid Lynx (10.04.x LTS). Other versions of Ubuntu or other
 variants of GNU/Linux might require different configurations.</p>
 <h3 id="using-a-separate-output-directory">Using a separate output directory</h3>
 <p>By default, the output of each build is stored in the <code>out/</code>
 subdirectory of the matching source tree.</p>
 <p>On some machines with multiple storage devices, builds are
 faster when storing the source files and the output on
 separate volumes. For additional performance, the output
 can be stored on a filesystem optimized for speed instead
 of crash robustness, since all files can be re-generated
 in case of filesystem corruption.</p>
 <p>To set this up, export the <code>OUT_DIR_COMMON_BASE</code> variable
 to point to the location where your output directories
 will be stored.</p>
 <pre><code>export OUT_DIR_COMMON_BASE=&lt;path-to-your-out-directory&gt;
 </code></pre>
 <p>The output directory for each separate source tree will be
 named after the directory holding the source tree.</p>
 <p>For instance, if you have source trees as <code>/source/master1</code>
 and <code>/source/master2</code> and <code>OUT_DIR_COMMON_BASE</code> is set to
 <code>/output</code>, the output directories will be <code>/output/master1</code>
 and <code>/output/master2</code>.</p>
 <p>It's important in that case to not have multiple source
 trees stored in directories that have the same name,
 as those would end up sharing an output directory, with
 unpredictable results.</p>
 <p>This is only supported on Jelly Bean (4.1) and newer,
 including the <code>master</code> branch.</p>
 <h2 id="setting-up-a-mac-os-x-build-environment">Setting up a Mac OS build environment</h2>
 <p>In a default installation, Mac OS runs on a case-preserving but case-insensitive
 filesystem. This type of filesystem is not supported by git and will cause some
 git commands (such as <code>git status</code>) to behave abnormally. Because of this, we
 recommend that you always work with the AOSP source files on a case-sensitive
 filesystem. This can be done fairly easily using a disk image, discussed below.</p>
 <p>Once the proper filesystem is available, building the <code>master</code> branch in a modern
 Mac OS environment is very straightforward. Earlier branches, including ICS,
 require some additional tools and SDKs.</p>
 <h3 id="creating-a-case-sensitive-disk-image">Creating a case-sensitive disk image</h3>
 <p>You can create a case-sensitive filesystem within your existing Mac OS environment
 using a disk image. To create the image, launch Disk
 Utility and select "New Image".  A size of 25GB is the minimum to
 complete the build; larger numbers are more future-proof. Using sparse images
 saves space while allowing to grow later as the need arises. Be sure to select
 "case sensitive, journaled" as the volume format.</p>
 <p>You can also create it from a shell with the following command:</p>
 <pre><code># hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 40g ~/android.dmg
 </code></pre>
 <p>This will create a <code>.dmg</code> (or possibly a <code>.dmg.sparseimage</code>) file which, once mounted, acts as a drive with the required formatting for Android development.
 <p>If you need a larger volume later, you can also resize the sparse image with the following command:</p>
 <pre><code># hdiutil resize -size &lt;new-size-you-want&gt;g ~/android.dmg.sparseimage
 </code></pre>
 For a disk image named <code>android.dmg</code> stored in your home directory, you can add helper functions to your <code>~/.bash_profile</code>:
 <ul>
 <li>
 To mount the image when you execute <code>mountAndroid</code>:</p>
 <pre><code># mount the android file image
 function mountAndroid { hdiutil attach ~/android.dmg -mountpoint /Volumes/android; }
 </code></pre>
 <p><strong>Note</strong>: If your system created a <code>.dmg.sparseimage</code> file, replace <code>~/android.dmg</code> with <code>~/android.dmg.sparseimage</code>.</p>
 </li>
 <li>
 <p>To unmount it when you execute <code>umountAndroid</code>:</p>
 <pre><code># unmount the android file image
 function umountAndroid() { hdiutil detach /Volumes/android; }
 </code></pre>
 </li>
 </ul>
 <p>Once you've mounted the <code>android</code> volume, you'll do all your work there. You can eject it (unmount it) just like you would with an external drive.</p>

 <h3 id="installing-the-mac-jdk">Installing the JDK</h3>
 <p>The <code>master</code> and <code>5.0.x</code> branches of Android in the <a
 href="https://android.googlesource.com/">Android Open Source Project (AOSP)</a>
 require Java 7. On Mac OS, use <a
 href="https://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html#jdk-7u71-oth-JPR">jdk-7u71-macosx-x64.dmg</a>.</p>

 <p>To develop for versions of Android Gingerbread through KitKat, download and
 install the Java 6 version of the <a
 href="http://support.apple.com/kb/dl1572">Java JDK</a>.</p>

 <h3 id="master-branch">Master branch</h3>
 <p>To build the latest source in a Mac OS environment, you will need an Intel/x86
 machine running Mac OS X v10.8 (Mountain Lion) or later, along with Xcode
 4.5.2 or later including the Command Line Tools.</p>

 <h3 id="branch-50x-and-all-earlier-branches">Branch 5.0.x and earlier branches</h3>
 <p>To build 5.0.x and earlier source in a Mac OS environment, you will need an Intel/x86
 machine running Mac OS X v10.8 (Mountain Lion), along with Xcode
 4.5.2 and Command Line Tools.</p>

 <h3 id="branch-44x-and-all-earlier-branches">Branch 4.4.x and earlier branches</h3>
 <p>To build 4.2.x and earlier source in a Mac OS environment, you will need an Intel/x86
 machine running Mac OS X v10.6 (Snow Leopard) or Mac OS X v10.7 (Lion), along with Xcode
 4.2 (Apple's Developer Tools). Although Lion does not come with a JDK, it should
 install automatically when you attempt to build the source.</p>
 <p>The remaining sections for Mac OS apply only to those who wish to build
 earlier branches.</p>

 <h3 id="branch-40x-and-all-earlier-branches">Branch 4.0.x and all earlier branches</h3>
 <p>To build android-4.0.x and earlier branches in a Mac OS environment, you need an
 Intel/x86 machine running Mac OS X v10.5 (Leopard) or Mac OS X v10.6 (Snow Leopard). You
 will need the Mac OS X v10.5 SDK.</p>
 <h4 id="installing-required-packages">Installing required packages</h4>
 <ul>
 <li>
 <p>Install Xcode from <a href="http://developer.apple.com/">the Apple developer site</a>.
 We recommend version 3.1.4 or newer (e.g., gcc 4.2).
 Version 4.x could cause difficulties.
 If you are not already registered as an Apple developer, you will have to
 create an Apple ID in order to download.</p>
 </li>
 <li>
 <p>Install MacPorts from <a href="http://www.macports.org/install.php">macports.org</a>.</p>
 <p><em>Note: Make sure that <code>/opt/local/bin</code> appears in your path BEFORE <code>/usr/bin</code>.  If not, add</em> </p>
 <pre><code>export PATH=/opt/local/bin:$PATH
 </code></pre>
 <p><em>to your <code>~/.bash_profile</code>.</em></p>

 <p><strong>Note</strong>: If you do not have a <code>.bash_profile</code> file in your home directory, create one.</p>

 </li>
 <li>
 <p>Get make, git, and GPG packages from MacPorts: </p>
 <pre><code>$ POSIXLY_CORRECT=1 sudo port install gmake libsdl git gnupg
 </code></pre>
 <p>If using Mac OS X v10.4, also install bison:</p>
 <pre><code>$ POSIXLY_CORRECT=1 sudo port install bison
 </code></pre>
 </li>
 </ul>
 <h4 id="reverting-from-make-382">Reverting from make 3.82</h4>
 <p>For versions of Android before ICS, there is a bug in gmake 3.82 that prevents android from building.  You can install version 3.81 using MacPorts by taking the following steps:</p>
 <ul>
 <li>
 <p>Edit <code>/opt/local/etc/macports/sources.conf</code> and add a line that says</p>
 <pre><code>file:///Users/Shared/dports
 </code></pre>
 <p>above the rsync line.  Then create this directory: </p>
 <pre><code>$ mkdir /Users/Shared/dports
 </code></pre>
 </li>
 <li>
 <p>In the new <code>dports</code> directory, run </p>
 <pre><code>$ svn co --revision 50980 http://svn.macports.org/repository/macports/trunk/dports/devel/gmake/ devel/gmake/
 </code></pre>
 </li>
 <li>
 <p>Create a port index for your new local repository: </p>
 <pre><code>$ portindex /Users/Shared/dports
 </code></pre>
 </li>
 <li>
 <p>Finally, install the old version of gmake with </p>
 <pre><code>$ sudo port install gmake @3.81
 </code></pre>
 </li>
 </ul>
 <h4 id="setting-a-file-descriptor-limit">Setting a file descriptor limit</h4>
 <p>On Mac OS, the default limit on the number of simultaneous file descriptors open is too low and a highly parallel build process may exceed this limit.<br />
 </p>
 <p>To increase the cap, add the following lines to your <code>~/.bash_profile</code>: </p>
 <pre><code># set the number of open files to be 1024
 ulimit -S -n 1024
 </code></pre>
 <h2 id="optimizing-a-build-environment">Optimizing a build environment (optional)</h2>
 <p><a name="ccache"></a></p>
 <h3 id="setting-up-ccache">Setting up ccache</h3>
 <p>You can optionally tell the build to use the ccache compilation tool.
 Ccache acts as a compiler cache that can be used to speed up rebuilds.
 This works very well if you use <code>make clean</code> often, or if you frequently
 switch between different build products.</p>
 <p>Put the following in your <code>.bashrc</code> (or equivalent):</p>
 <pre><code>export USE_CCACHE=1
 </code></pre>
 <p>By default the cache will be stored in <code>~/.ccache</code>.
 If your home directory is on NFS or some other non-local filesystem,
 you will want to specify the directory in your <code>.bashrc</code> file as well:</p>
 <pre><code>export CCACHE_DIR=&lt;path-to-your-cache-directory&gt;
 </code></pre>
 <p>The suggested cache size is 50-100GB.
 You will need to run the following command once you have downloaded
 the source code:</p>
 <pre><code>prebuilts/misc/linux-x86/ccache/ccache -M 50G
 </code></pre>
 <p>On Mac OS, you should replace <code>linux-x86</code> with <code>darwin-x86</code>:</p>
 <pre><code>prebuilts/misc/darwin-x86/ccache/ccache -M 50G
 </code></pre>
 <p>When building Ice Cream Sandwich (4.0.x) or older, ccache is in
 a different location:</p>
 <pre><code>prebuilt/linux-x86/ccache/ccache -M 50G
 </code></pre>
 <p>This setting is stored in the CCACHE_DIR and is persistent.</p>
 <h2 id="next-download-the-source">Next: Download the source</h2>
 <p>Your build environment is good to go! Proceed to <a href="downloading.html">downloading the source</a>.</p>
	page.title=Initializing a Build Environment
	@jd:body

	<!--
	Copyright 2015 The Android Open Source Project

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software
	distributed under the License is distributed on an "AS IS" BASIS,
	WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	See the License for the specific language governing permissions and
	limitations under the License.
	-->
	<div id="qv-wrapper">
	<div id="qv">
	<h2>In this document</h2>
	<ol id="auto-toc">
	</ol>
	</div>
	</div>

	<p>This section describes how to set up your local work environment to build
	the Android source files. You will need to use Linux or Mac OS. Building under
	Windows is not currently supported.</p>
	<p>For an overview of the entire code-review and code-update process, see <a
	href="life-of-a-patch.html">Life of a Patch</a>.</p>
	<h2 id="choosing-a-branch">Choosing a Branch</h2>
	<p>Some of the requirements for your build environment are determined by which
	version of the source code you plan to compile. See
	<a href="build-numbers.html">Build Numbers</a> for a full listing of branches you may
	choose from. You may also choose to download and build the latest source code
	(called <code>master</code>), in which case you will simply omit the branch specification
	when you initialize the repository.</p>
	<p>Once you have selected a branch, follow the appropriate instructions below to
	set up your build environment.</p>
	<h2 id="setting-up-a-linux-build-environment">Setting up a Linux build environment</h2>
	<p>These instructions apply to all branches, including <code>master</code>.</p>
	<p>The Android build is routinely tested in house on recent versions of
	Ubuntu LTS (14.04), but most distributions should have the required
	build tools available. Reports of successes or failures on other
	distributions are welcome.</p>
	<p>For Gingerbread (2.3.x) and newer versions, including the <code>master</code>
	branch, a 64-bit environment is required. Older versions can be
	compiled on 32-bit systems.</p>
	<p><strong>Note</strong>: See the <a href="building.html">Downloading and
	Building</a> page for the list of hardware and software requirements. Then
	follow the detailed instructions for Ubuntu and Mac OS below.</p>

	<h3 id="installing-the-jdk">Installing the JDK</h3>
	<p>The <code>master</code> branch of Android in the <a
	href="https://android.googlesource.com/">Android Open Source Project (AOSP)</a>
	requires Java 7. On Ubuntu, use <a href="http://openjdk.java.net/install/">OpenJDK</a>.</p>
	<p>Java 7: For the latest version of Android</p>
	<pre><code>$ sudo apt-get update
	$ sudo apt-get install openjdk-7-jdk
	</code></pre>

	<p>Optionally, update the default Java version by running:</p>
	<pre><code>$ sudo update-alternatives --config java
	$ sudo update-alternatives --config javac
	</code></pre>

	<p>If you encounter version errors for Java, set its
	path as described in the <a href="building-running.html#wrong-java-version">Wrong
	Java Version</a> section.</p>

	<p>To develop older versions of Android, download and install the corresponding version of the <a
	href="http://www.oracle.com/technetwork/java/javase/archive-139210.html">Java JDK</a>:<br/>
	Java 6: for Gingerbread through KitKat<br/>
	Java 5: for Cupcake through Froyo</p>

	<p><strong>Note</strong>: The <code>lunch</code> command in the build step will ensure that the Sun JDK is
	used instead of any previously installed JDK.</p>

	<h3 id="installing-required-packages-ubuntu-1404">Installing required packages (Ubuntu 14.04)</h3>
	<p>You will need a 64-bit version of Ubuntu. Ubuntu 14.04 is recommended.</p>
	<pre><code>$ sudo apt-get install bison g++-multilib git gperf libxml2-utils make zlib1g-dev:i386 zip</code></pre>

	<h3 id="installing-required-packages-ubuntu-1204">Installing required packages (Ubuntu 12.04)</h3>
	<p>You may use Ubuntu 12.04 to build older versions of Android. Version 12.04 is not supported on master or recent releases.</p>
	<pre><code>$ sudo apt-get install git gnupg flex bison gperf build-essential \
	zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \
	libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \
	libgl1-mesa-dev g++-multilib mingw32 tofrodos \
	python-markdown libxml2-utils xsltproc zlib1g-dev:i386
	$ sudo ln -s /usr/lib/i386-linux-gnu/mesa/libGL.so.1 /usr/lib/i386-linux-gnu/libGL.so
	</code></pre>

	<h3 id="installing-required-packages-ubuntu-1004-1110">Installing required packages (Ubuntu 10.04 -- 11.10)</h3>
	<p>Building on Ubuntu 10.04-11.10 is no longer supported, but may be useful for building older
	releases of AOSP.</p>
	<pre><code>$ sudo apt-get install git gnupg flex bison gperf build-essential \
	zip curl zlib1g-dev libc6-dev lib32ncurses5-dev ia32-libs \
	x11proto-core-dev libx11-dev lib32readline5-dev lib32z-dev \
	libgl1-mesa-dev g++-multilib mingw32 tofrodos python-markdown \
	libxml2-utils xsltproc
	</code></pre>
	<p>On Ubuntu 10.10:</p>
	<pre><code>$ sudo ln -s /usr/lib32/mesa/libGL.so.1 /usr/lib32/mesa/libGL.so
	</code></pre>
	<p>On Ubuntu 11.10:</p>
	<pre><code>$ sudo apt-get install libx11-dev:i386
	</code></pre>
	<h3 id="configuring-usb-access">Configuring USB Access</h3>
	<p>Under GNU/Linux systems (and specifically under Ubuntu systems),
	regular users can't directly access USB devices by default. The
	system needs to be configured to allow such access.</p>
	<p>The recommended approach is to create a file
	<code>/etc/udev/rules.d/51-android.rules</code> (as the root user) and to copy
	the following lines in it. <code><username></code> must be replaced by the
	actual username of the user who is authorized to access the phones
	over USB.</p>
	<pre><code># adb protocol on passion (Nexus One)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e12", MODE="0600", OWNER="<username>"
	# fastboot protocol on passion (Nexus One)
	SUBSYSTEM=="usb", ATTR{idVendor}=="0bb4", ATTR{idProduct}=="0fff", MODE="0600", OWNER="<username>"
	# adb protocol on crespo/crespo4g (Nexus S)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e22", MODE="0600", OWNER="<username>"
	# fastboot protocol on crespo/crespo4g (Nexus S)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e20", MODE="0600", OWNER="<username>"
	# adb protocol on stingray/wingray (Xoom)
	SUBSYSTEM=="usb", ATTR{idVendor}=="22b8", ATTR{idProduct}=="70a9", MODE="0600", OWNER="<username>"
	# fastboot protocol on stingray/wingray (Xoom)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="708c", MODE="0600", OWNER="<username>"
	# adb protocol on maguro/toro (Galaxy Nexus)
	SUBSYSTEM=="usb", ATTR{idVendor}=="04e8", ATTR{idProduct}=="6860", MODE="0600", OWNER="<username>"
	# fastboot protocol on maguro/toro (Galaxy Nexus)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e30", MODE="0600", OWNER="<username>"
	# adb protocol on panda (PandaBoard)
	SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d101", MODE="0600", OWNER="<username>"
	# adb protocol on panda (PandaBoard ES)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="d002", MODE="0600", OWNER="<username>"
	# fastboot protocol on panda (PandaBoard)
	SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d022", MODE="0600", OWNER="<username>"
	# usbboot protocol on panda (PandaBoard)
	SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d00f", MODE="0600", OWNER="<username>"
	# usbboot protocol on panda (PandaBoard ES)
	SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d010", MODE="0600", OWNER="<username>"
	# adb protocol on grouper/tilapia (Nexus 7)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e42", MODE="0600", OWNER="<username>"
	# fastboot protocol on grouper/tilapia (Nexus 7)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e40", MODE="0600", OWNER="<username>"
	# adb protocol on manta (Nexus 10)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4ee2", MODE="0600", OWNER="<username>"
	# fastboot protocol on manta (Nexus 10)
	SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4ee0", MODE="0600", OWNER="<username>"
	</code></pre>
	<p>Those new rules take effect the next time a device is plugged in.
	It might therefore be necessary to unplug the device and plug it
	back into the computer.</p>
	<p>This is known to work on both Ubuntu Hardy Heron (8.04.x LTS) and
	Lucid Lynx (10.04.x LTS). Other versions of Ubuntu or other
	variants of GNU/Linux might require different configurations.</p>
	<h3 id="using-a-separate-output-directory">Using a separate output directory</h3>
	<p>By default, the output of each build is stored in the <code>out/</code>
	subdirectory of the matching source tree.</p>
	<p>On some machines with multiple storage devices, builds are
	faster when storing the source files and the output on
	separate volumes. For additional performance, the output
	can be stored on a filesystem optimized for speed instead
	of crash robustness, since all files can be re-generated
	in case of filesystem corruption.</p>
	<p>To set this up, export the <code>OUT_DIR_COMMON_BASE</code> variable
	to point to the location where your output directories
	will be stored.</p>
	<pre><code>export OUT_DIR_COMMON_BASE=<path-to-your-out-directory>
	</code></pre>
	<p>The output directory for each separate source tree will be
	named after the directory holding the source tree.</p>
	<p>For instance, if you have source trees as <code>/source/master1</code>
	and <code>/source/master2</code> and <code>OUT_DIR_COMMON_BASE</code> is set to
	<code>/output</code>, the output directories will be <code>/output/master1</code>
	and <code>/output/master2</code>.</p>
	<p>It's important in that case to not have multiple source
	trees stored in directories that have the same name,
	as those would end up sharing an output directory, with
	unpredictable results.</p>
	<p>This is only supported on Jelly Bean (4.1) and newer,
	including the <code>master</code> branch.</p>
	<h2 id="setting-up-a-mac-os-x-build-environment">Setting up a Mac OS build environment</h2>
	<p>In a default installation, Mac OS runs on a case-preserving but case-insensitive
	filesystem. This type of filesystem is not supported by git and will cause some
	git commands (such as <code>git status</code>) to behave abnormally. Because of this, we
	recommend that you always work with the AOSP source files on a case-sensitive
	filesystem. This can be done fairly easily using a disk image, discussed below.</p>
	<p>Once the proper filesystem is available, building the <code>master</code> branch in a modern
	Mac OS environment is very straightforward. Earlier branches, including ICS,
	require some additional tools and SDKs.</p>
	<h3 id="creating-a-case-sensitive-disk-image">Creating a case-sensitive disk image</h3>
	<p>You can create a case-sensitive filesystem within your existing Mac OS environment
	using a disk image. To create the image, launch Disk
	Utility and select "New Image". A size of 25GB is the minimum to
	complete the build; larger numbers are more future-proof. Using sparse images
	saves space while allowing to grow later as the need arises. Be sure to select
	"case sensitive, journaled" as the volume format.</p>
	<p>You can also create it from a shell with the following command:</p>
	<pre><code># hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 40g ~/android.dmg
	</code></pre>
	<p>This will create a <code>.dmg</code> (or possibly a <code>.dmg.sparseimage</code>) file which, once mounted, acts as a drive with the required formatting for Android development.
	<p>If you need a larger volume later, you can also resize the sparse image with the following command:</p>
	<pre><code># hdiutil resize -size <new-size-you-want>g ~/android.dmg.sparseimage
	</code></pre>
	For a disk image named <code>android.dmg</code> stored in your home directory, you can add helper functions to your <code>~/.bash_profile</code>:
	<ul>
	<li>
	To mount the image when you execute <code>mountAndroid</code>:</p>
	<pre><code># mount the android file image
	function mountAndroid { hdiutil attach ~/android.dmg -mountpoint /Volumes/android; }
	</code></pre>
	<p><strong>Note</strong>: If your system created a <code>.dmg.sparseimage</code> file, replace <code>~/android.dmg</code> with <code>~/android.dmg.sparseimage</code>.</p>
	</li>
	<li>
	<p>To unmount it when you execute <code>umountAndroid</code>:</p>
	<pre><code># unmount the android file image
	function umountAndroid() { hdiutil detach /Volumes/android; }
	</code></pre>
	</li>
	</ul>
	<p>Once you've mounted the <code>android</code> volume, you'll do all your work there. You can eject it (unmount it) just like you would with an external drive.</p>

	<h3 id="installing-the-mac-jdk">Installing the JDK</h3>
	<p>The <code>master</code> and <code>5.0.x</code> branches of Android in the <a
	href="https://android.googlesource.com/">Android Open Source Project (AOSP)</a>
	require Java 7. On Mac OS, use <a
	href="https://www.oracle.com/technetwork/java/javase/downloads/java-archive-downloads-javase7-521261.html#jdk-7u71-oth-JPR">jdk-7u71-macosx-x64.dmg</a>.</p>

	<p>To develop for versions of Android Gingerbread through KitKat, download and
	install the Java 6 version of the <a
	href="http://support.apple.com/kb/dl1572">Java JDK</a>.</p>

	<h3 id="master-branch">Master branch</h3>
	<p>To build the latest source in a Mac OS environment, you will need an Intel/x86
	machine running Mac OS X v10.8 (Mountain Lion) or later, along with Xcode
	4.5.2 or later including the Command Line Tools.</p>

	<h3 id="branch-50x-and-all-earlier-branches">Branch 5.0.x and earlier branches</h3>
	<p>To build 5.0.x and earlier source in a Mac OS environment, you will need an Intel/x86
	machine running Mac OS X v10.8 (Mountain Lion), along with Xcode
	4.5.2 and Command Line Tools.</p>

	<h3 id="branch-44x-and-all-earlier-branches">Branch 4.4.x and earlier branches</h3>
	<p>To build 4.2.x and earlier source in a Mac OS environment, you will need an Intel/x86
	machine running Mac OS X v10.6 (Snow Leopard) or Mac OS X v10.7 (Lion), along with Xcode
	4.2 (Apple's Developer Tools). Although Lion does not come with a JDK, it should
	install automatically when you attempt to build the source.</p>
	<p>The remaining sections for Mac OS apply only to those who wish to build
	earlier branches.</p>

	<h3 id="branch-40x-and-all-earlier-branches">Branch 4.0.x and all earlier branches</h3>
	<p>To build android-4.0.x and earlier branches in a Mac OS environment, you need an
	Intel/x86 machine running Mac OS X v10.5 (Leopard) or Mac OS X v10.6 (Snow Leopard). You
	will need the Mac OS X v10.5 SDK.</p>
	<h4 id="installing-required-packages">Installing required packages</h4>
	<ul>
	<li>
	<p>Install Xcode from <a href="http://developer.apple.com/">the Apple developer site</a>.
	We recommend version 3.1.4 or newer (e.g., gcc 4.2).
	Version 4.x could cause difficulties.
	If you are not already registered as an Apple developer, you will have to
	create an Apple ID in order to download.</p>
	</li>
	<li>
	<p>Install MacPorts from <a href="http://www.macports.org/install.php">macports.org</a>.</p>
	<p><em>Note: Make sure that <code>/opt/local/bin</code> appears in your path BEFORE <code>/usr/bin</code>. If not, add</em> </p>
	<pre><code>export PATH=/opt/local/bin:$PATH
	</code></pre>
	<p><em>to your <code>~/.bash_profile</code>.</em></p>

	<p><strong>Note</strong>: If you do not have a <code>.bash_profile</code> file in your home directory, create one.</p>

	</li>
	<li>
	<p>Get make, git, and GPG packages from MacPorts: </p>
	<pre><code>$ POSIXLY_CORRECT=1 sudo port install gmake libsdl git gnupg
	</code></pre>
	<p>If using Mac OS X v10.4, also install bison:</p>
	<pre><code>$ POSIXLY_CORRECT=1 sudo port install bison
	</code></pre>
	</li>
	</ul>
	<h4 id="reverting-from-make-382">Reverting from make 3.82</h4>
	<p>For versions of Android before ICS, there is a bug in gmake 3.82 that prevents android from building. You can install version 3.81 using MacPorts by taking the following steps:</p>
	<ul>
	<li>
	<p>Edit <code>/opt/local/etc/macports/sources.conf</code> and add a line that says</p>
	<pre><code>file:///Users/Shared/dports
	</code></pre>
	<p>above the rsync line. Then create this directory: </p>
	<pre><code>$ mkdir /Users/Shared/dports
	</code></pre>
	</li>
	<li>
	<p>In the new <code>dports</code> directory, run </p>
	<pre><code>$ svn co --revision 50980 http://svn.macports.org/repository/macports/trunk/dports/devel/gmake/ devel/gmake/
	</code></pre>
	</li>
	<li>
	<p>Create a port index for your new local repository: </p>
	<pre><code>$ portindex /Users/Shared/dports
	</code></pre>
	</li>
	<li>
	<p>Finally, install the old version of gmake with </p>
	<pre><code>$ sudo port install gmake @3.81
	</code></pre>
	</li>
	</ul>
	<h4 id="setting-a-file-descriptor-limit">Setting a file descriptor limit</h4>
	<p>On Mac OS, the default limit on the number of simultaneous file descriptors open is too low and a highly parallel build process may exceed this limit.<br />
	</p>
	<p>To increase the cap, add the following lines to your <code>~/.bash_profile</code>: </p>
	<pre><code># set the number of open files to be 1024
	ulimit -S -n 1024
	</code></pre>
	<h2 id="optimizing-a-build-environment">Optimizing a build environment (optional)</h2>
	<p><a name="ccache"></a></p>
	<h3 id="setting-up-ccache">Setting up ccache</h3>
	<p>You can optionally tell the build to use the ccache compilation tool.
	Ccache acts as a compiler cache that can be used to speed up rebuilds.
	This works very well if you use <code>make clean</code> often, or if you frequently
	switch between different build products.</p>
	<p>Put the following in your <code>.bashrc</code> (or equivalent):</p>
	<pre><code>export USE_CCACHE=1
	</code></pre>
	<p>By default the cache will be stored in <code>~/.ccache</code>.
	If your home directory is on NFS or some other non-local filesystem,
	you will want to specify the directory in your <code>.bashrc</code> file as well:</p>
	<pre><code>export CCACHE_DIR=<path-to-your-cache-directory>
	</code></pre>
	<p>The suggested cache size is 50-100GB.
	You will need to run the following command once you have downloaded
	the source code:</p>
	<pre><code>prebuilts/misc/linux-x86/ccache/ccache -M 50G
	</code></pre>
	<p>On Mac OS, you should replace <code>linux-x86</code> with <code>darwin-x86</code>:</p>
	<pre><code>prebuilts/misc/darwin-x86/ccache/ccache -M 50G
	</code></pre>
	<p>When building Ice Cream Sandwich (4.0.x) or older, ccache is in
	a different location:</p>
	<pre><code>prebuilt/linux-x86/ccache/ccache -M 50G
	</code></pre>
	<p>This setting is stored in the CCACHE_DIR and is persistent.</p>
	<h2 id="next-download-the-source">Next: Download the source</h2>
	<p>Your build environment is good to go! Proceed to <a href="downloading.html">downloading the source</a>.</p>