en/setup/build/initializing.html - platform/docs/source.android.com - Git at Google

 <html devsite>
   <head>
     <title>Establishing a Build Environment</title>
     <meta name="project_path" value="/_project.yaml" />
     <meta name="book_path" value="/_book.yaml" />
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 <p>
   This section describes how to set up your local work environment to build
   the Android source files. You must 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="../contribute/life-of-a-patch.html">Life of a Patch</a>.
 </p>
 <aside class="note"><strong>Note:</strong> All commands in this site are
   preceded by a dollar sign ($) to differentiate them from output or entries
   within files. You may use the <em>Click to copy</em> feature at the top right
   of each command box to copy all lines without the dollar signs or triple-click
   each line to copy it individually without the dollar sign.
 </aside>

 <h2 id="choosing-a-branch">Choosing a branch</h2>
 <p>
   Some requirements for the build environment are determined by the version of
   the source code you plan to compile. For a full list of available branches,
   see <a href="../start/build-numbers.html">Build Numbers</a>. You can 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>
   After 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) and Debian testing. Most other distributions should
   have the required build tools available.
 </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>
 <aside class="note"><strong>Note:</strong> See
   <a href="requirements.html">Requirements</a> for the complete list of hardware
   and software requirements, then follow the detailed instructions for Ubuntu
   and Mac OS below.
 </aside>

 <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/" class="external">Android Open
   Source Project (AOSP)</a> comes with prebuilt versions of OpenJDK below
   <code>prebuilts/jdk/</code> so no additional installation is required.
 </p>
 <p>
   Older versions of Android require a separate installation of the JDK. On
   Ubuntu, use
   <a href="http://openjdk.java.net/install/" class="external">OpenJDK</a>. See
   <a href="requirements.html#jdk">JDK Requirements</a> for precise versions and
   the sections below for instructions.
 </p>
 <h4 id="for-ubuntu-15-04">For Ubuntu &gt;= 15.04</h4>
 <p>
   Run the following:
 </p>
 <pre class="devsite-click-to-copy">
 <code class="devsite-terminal">sudo apt-get update</code>
 <code class="devsite-terminal">sudo apt-get install openjdk-8-jdk</code>
 </pre>

 <h4 id="for-ubuntu-14-04">For Ubuntu LTS 14.04</h4>
 <p>
   There are no available supported OpenJDK 8 packages for Ubuntu 14.04. The
   <strong>Ubuntu 15.04 OpenJDK 8</strong> packages have been used successfully
   with Ubuntu 14.04. <em>Newer package versions (e.g. those for 15.10, 16.04) were
   found not to work on 14.04 using the instructions below.</em>
 </p>
 <ol>
   <li>Download the <code>.deb</code> packages for 64-bit architecture from
     <a href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/">old-releases.ubuntu.com</a>:
     <ul>
       <li><a
         href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre-headless_8u45-b14-1_amd64.deb">openjdk-8-jre-headless_8u45-b14-1_amd64.deb</a>
         with SHA256 <code>0f5aba8db39088283b51e00054813063173a4d8809f70033976f83e214ab56c0</code>
       </li>
       <li><a
         href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre_8u45-b14-1_amd64.deb">openjdk-8-jre_8u45-b14-1_amd64.deb</a>
         with SHA256 <code>9ef76c4562d39432b69baf6c18f199707c5c56a5b4566847df908b7d74e15849</code>
       </li>
       <li><a
         href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jdk_8u45-b14-1_amd64.deb">openjdk-8-jdk_8u45-b14-1_amd64.deb</a>
         with SHA256 <code>6e47215cf6205aa829e6a0a64985075bd29d1f428a4006a80c9db371c2fc3c4c</code>
       </li>
     </ul>
   </li>
   <li>Optionally, confirm the checksums of the downloaded files against the
     SHA256 string listed with each package above. For example, with the
     <code>sha256sum</code> tool:
     <pre class="devsite-terminal devsite-click-to-copy">
     sha256sum {downloaded.deb file}</pre>
   </li>
   <li>Install the packages:
     <pre class="devsite-terminal devsite-click-to-copy">
     sudo apt-get update</pre>
     Run <code>dpkg</code> for each of the .deb files you downloaded. It may
     produce errors due to missing dependencies:
     <pre class="devsite-terminal devsite-click-to-copy">
     sudo dpkg -i {downloaded.deb file}</pre>
     To fix missing dependencies:
     <pre class="devsite-terminal devsite-click-to-copy">
     sudo apt-get -f install</pre>
   </li>
 </ol>

 <h4 id="default-java-version">Update the default Java version - optional</h4>
 <p>
   Optionally, for the Ubuntu versions above update the default Java version by
   running:
 </p>
 <pre class="devsite-click-to-copy">
 <code class="devsite-terminal">sudo update-alternatives --config java</code>
 <code class="devsite-terminal">sudo update-alternatives --config javac</code>
 </pre>
 <aside class="note">
   <b>Note:</b> If, during a build, you encounter version errors for Java, see
   <a href="building.html#wrong-java-version">Wrong Java version</a> for likely
   causes and solutions.
  </aside>

 <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 class="devsite-terminal devsite-click-to-copy">
 sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache libgl1-mesa-dev libxml2-utils xsltproc unzip
 </pre>
 <aside class="note"><strong>Note:</strong> To use SELinux tools for policy
   analysis, also install the <code>python-networkx</code> package.
 </aside>
 <aside class="note"><strong>Note:</strong> If you are using LDAP and want
   to run ART host tests, also install the <code>libnss-sss:i386</code>
   package.
 </aside>

 <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 class="devsite-click-to-copy">
 <code class="devsite-terminal">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</code>
 <code class="devsite-terminal">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 class="devsite-terminal devsite-click-to-copy">
 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
 </pre>
 <p>
   On Ubuntu 10.10:
 </p>
 <pre class="devsite-terminal devsite-click-to-copy">
 sudo ln -s /usr/lib32/mesa/libGL.so.1 /usr/lib32/mesa/libGL.so
 </pre>
 <p>
   On Ubuntu 11.10:
 </p>
 <pre class="devsite-terminal devsite-click-to-copy">
 sudo apt-get install libx11-dev:i386
 </pre>

 <h3 id="configuring-usb-access">Configuring USB access</h3>
 <p>
   Install a community-maintained default set of <code>udev</code> rules for
   all Android devices by following the instructions to <a
     href="https://developer.android.com/studio/run/device.html#setting-up"
     class="external">Set up a device for development</a>.
 </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 class="devsite-terminal devsite-click-to-copy">
 export OUT_DIR_COMMON_BASE=&lt;path-to-your-out-directory&gt;
 </pre>
 <p>
   The output directory for each separate source tree will be named after the
   directory holding the source tree. 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. 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 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 <strong>New Image</strong>. 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
   <strong>case sensitive, journaled</strong> as the volume format.
 </p>
 <p>
   You can also create it from a shell with the following command:
 </p>
 <pre class="devsite-click-to-copy devsite-terminal" data-terminal-prefix="# ">
 hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 40g ~/android.dmg
 </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>
 <p>
   If you need a larger volume later, you can also resize the sparse image with
   the following command:
 </p>
 <pre class="devsite-click-to-copy devsite-terminal" data-terminal-prefix="# ">hdiutil resize -size &lt;new-size-you-want&gt;g ~/android.dmg.sparseimage
 </pre>
 <p>
   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>:
 </p>
 <ul>
   <li>To mount the image when you execute <code>mountAndroid</code>:
     <pre class="devsite-click-to-copy">
     # mount the android file image
     mountAndroid() { hdiutil attach ~/android.dmg -mountpoint /Volumes/android; }</pre>
     <aside class="note"><strong>Note:</strong> If your system created a
       <code>.dmg.sparseimage</code> file, replace <code>~/android.dmg</code> with
       <code>~/android.dmg.sparseimage</code>.
     </aside>
   </li>
   <li>To unmount it when you execute <code>umountAndroid</code>:
     <pre class="devsite-click-to-copy">
      # unmount the android file image
      umountAndroid() { hdiutil detach /Volumes/android; }</pre>
   </li>
 </ul>
 <p>
   After you've mounted the <code>android</code> volume, you'll do all your work
   there. You can eject it (unmount it) just as you would an external drive.
 </p>

 <h3 id="installing-the-mac-jdk">Installing the JDK</h3>
 <p>
   See <a href="requirements.html">Requirements</a> for the version of Java to
   use when developing various versions of Android.
 </p>

 <h4 id="installing-required-packages">Installing required packages</h4>
 <ol>
   <li>Install Xcode command line tools with:
     <pre class="devsite-terminal devsite-click-to-copy">
     xcode-select --install</pre>
     For older versions of Mac OS (10.8 or earlier), you must install Xcode from
     the <a href="http://developer.apple.com/" class="external">Apple developer
     site</a>. If you are not already registered as an Apple developer, you must
     must create an Apple ID to download.
   </li>
   <li>Install MacPorts from
     <a href="http://www.macports.org/install.php">macports.org</a>. Ensure
     <code>/opt/local/bin</code> appears in your path <strong>before</strong>
     <code>/usr/bin</code>. If not, add the following to your
     <code>~/.bash_profile</code> file:
     <pre class="devsite-click-to-copy">
     export PATH=/opt/local/bin:$PATH</pre>
     <aside class="note"><strong>Note:</strong> If you do not have a
         <code>.bash_profile</code> file in your home directory, create one.
     </aside>
   </li>
   <li>Get make, git, and GPG packages from MacPorts:
     <pre class="devsite-terminal devsite-click-to-copy">
     POSIXLY_CORRECT=1 sudo port install gmake libsdl git gnupg</pre>
     If using Mac OS X v10.4, also install bison:
     <pre class="devsite-terminal devsite-click-to-copy">
     POSIXLY_CORRECT=1 sudo port install bison</pre>
   </li>
 </ol>

 <h4 id="reverting-from-make-382">Reverting from make 3.82</h4>
 <p>
   In Android 4.0.x (Ice Cream Sandwich) and earlier, a bug exists in gmake 3.82
   that prevents Android from building. You can install version 3.81 using
   MacPorts with these steps:
 </p>
 <ol>
   <li>Edit <code>/opt/local/etc/macports/sources.conf</code> and add a line that
     says:
     <pre class="devsite-click-to-copy">
     file:///Users/Shared/dports</pre>
     above the rsync line. Then create this directory:
     <pre class="devsite-terminal devsite-click-to-copy">
     mkdir /Users/Shared/dports</pre>
   </li>
   <li>In the new <code>dports</code> directory, run:
     <pre class="devsite-terminal devsite-click-to-copy">
     svn co --revision 50980 http://svn.macports.org/repository/macports/trunk/dports/devel/gmake/ devel/gmake/</pre>
   </li>
   <li>Create a port index for your new local repository:
     <pre class="devsite-terminal devsite-click-to-copy">
     portindex /Users/Shared/dports</pre>
   </li>
   <li>Install the old version of gmake with:
     <pre class="devsite-terminal devsite-click-to-copy">
     sudo port install gmake @3.81</pre>
   </li>
 </ol>

 <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. To
   increase the cap, add the following lines to your
   <code>~/.bash_profile</code>:
 </p>
 <pre class="devsite-click-to-copy">
 # set the number of open files to be 1024
 ulimit -S -n 1024</pre>

 <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>

   </body>
 </html>
	<html devsite>
	<head>
	<title>Establishing a Build Environment</title>
	<meta name="project_path" value="/_project.yaml" />
	<meta name="book_path" value="/_book.yaml" />
	</head>
	<body>
	<!--
	Copyright 2017 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.
	-->

	<p>
	This section describes how to set up your local work environment to build
	the Android source files. You must 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="../contribute/life-of-a-patch.html">Life of a Patch</a>.
	</p>
	<aside class="note"><strong>Note:</strong> All commands in this site are
	preceded by a dollar sign ($) to differentiate them from output or entries
	within files. You may use the <em>Click to copy</em> feature at the top right
	of each command box to copy all lines without the dollar signs or triple-click
	each line to copy it individually without the dollar sign.
	</aside>

	<h2 id="choosing-a-branch">Choosing a branch</h2>
	<p>
	Some requirements for the build environment are determined by the version of
	the source code you plan to compile. For a full list of available branches,
	see <a href="../start/build-numbers.html">Build Numbers</a>. You can 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>
	After 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) and Debian testing. Most other distributions should
	have the required build tools available.
	</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>
	<aside class="note"><strong>Note:</strong> See
	<a href="requirements.html">Requirements</a> for the complete list of hardware
	and software requirements, then follow the detailed instructions for Ubuntu
	and Mac OS below.
	</aside>

	<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/" class="external">Android Open
	Source Project (AOSP)</a> comes with prebuilt versions of OpenJDK below
	<code>prebuilts/jdk/</code> so no additional installation is required.
	</p>
	<p>
	Older versions of Android require a separate installation of the JDK. On
	Ubuntu, use
	<a href="http://openjdk.java.net/install/" class="external">OpenJDK</a>. See
	<a href="requirements.html#jdk">JDK Requirements</a> for precise versions and
	the sections below for instructions.
	</p>
	<h4 id="for-ubuntu-15-04">For Ubuntu >= 15.04</h4>
	<p>
	Run the following:
	</p>
	<pre class="devsite-click-to-copy">
	<code class="devsite-terminal">sudo apt-get update</code>
	<code class="devsite-terminal">sudo apt-get install openjdk-8-jdk</code>
	</pre>

	<h4 id="for-ubuntu-14-04">For Ubuntu LTS 14.04</h4>
	<p>
	There are no available supported OpenJDK 8 packages for Ubuntu 14.04. The
	<strong>Ubuntu 15.04 OpenJDK 8</strong> packages have been used successfully
	with Ubuntu 14.04. <em>Newer package versions (e.g. those for 15.10, 16.04) were
	found not to work on 14.04 using the instructions below.</em>
	</p>
	<ol>
	<li>Download the <code>.deb</code> packages for 64-bit architecture from
	<a href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/">old-releases.ubuntu.com</a>:
	<ul>
	<li><a
	href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre-headless_8u45-b14-1_amd64.deb">openjdk-8-jre-headless_8u45-b14-1_amd64.deb</a>
	with SHA256 <code>0f5aba8db39088283b51e00054813063173a4d8809f70033976f83e214ab56c0</code>
	</li>
	<li><a
	href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre_8u45-b14-1_amd64.deb">openjdk-8-jre_8u45-b14-1_amd64.deb</a>
	with SHA256 <code>9ef76c4562d39432b69baf6c18f199707c5c56a5b4566847df908b7d74e15849</code>
	</li>
	<li><a
	href="http://old-releases.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jdk_8u45-b14-1_amd64.deb">openjdk-8-jdk_8u45-b14-1_amd64.deb</a>
	with SHA256 <code>6e47215cf6205aa829e6a0a64985075bd29d1f428a4006a80c9db371c2fc3c4c</code>
	</li>
	</ul>
	</li>
	<li>Optionally, confirm the checksums of the downloaded files against the
	SHA256 string listed with each package above. For example, with the
	<code>sha256sum</code> tool:
	<pre class="devsite-terminal devsite-click-to-copy">
	sha256sum {downloaded.deb file}</pre>
	</li>
	<li>Install the packages:
	<pre class="devsite-terminal devsite-click-to-copy">
	sudo apt-get update</pre>
	Run <code>dpkg</code> for each of the .deb files you downloaded. It may
	produce errors due to missing dependencies:
	<pre class="devsite-terminal devsite-click-to-copy">
	sudo dpkg -i {downloaded.deb file}</pre>
	To fix missing dependencies:
	<pre class="devsite-terminal devsite-click-to-copy">
	sudo apt-get -f install</pre>
	</li>
	</ol>

	<h4 id="default-java-version">Update the default Java version - optional</h4>
	<p>
	Optionally, for the Ubuntu versions above update the default Java version by
	running:
	</p>
	<pre class="devsite-click-to-copy">
	<code class="devsite-terminal">sudo update-alternatives --config java</code>
	<code class="devsite-terminal">sudo update-alternatives --config javac</code>
	</pre>
	<aside class="note">
	<b>Note:</b> If, during a build, you encounter version errors for Java, see
	<a href="building.html#wrong-java-version">Wrong Java version</a> for likely
	causes and solutions.
	</aside>

	<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 class="devsite-terminal devsite-click-to-copy">
	sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache libgl1-mesa-dev libxml2-utils xsltproc unzip
	</pre>
	<aside class="note"><strong>Note:</strong> To use SELinux tools for policy
	analysis, also install the <code>python-networkx</code> package.
	</aside>
	<aside class="note"><strong>Note:</strong> If you are using LDAP and want
	to run ART host tests, also install the <code>libnss-sss:i386</code>
	package.
	</aside>

	<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 class="devsite-click-to-copy">
	<code class="devsite-terminal">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</code>
	<code class="devsite-terminal">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 class="devsite-terminal devsite-click-to-copy">
	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
	</pre>
	<p>
	On Ubuntu 10.10:
	</p>
	<pre class="devsite-terminal devsite-click-to-copy">
	sudo ln -s /usr/lib32/mesa/libGL.so.1 /usr/lib32/mesa/libGL.so
	</pre>
	<p>
	On Ubuntu 11.10:
	</p>
	<pre class="devsite-terminal devsite-click-to-copy">
	sudo apt-get install libx11-dev:i386
	</pre>

	<h3 id="configuring-usb-access">Configuring USB access</h3>
	<p>
	Install a community-maintained default set of <code>udev</code> rules for
	all Android devices by following the instructions to <a
	href="https://developer.android.com/studio/run/device.html#setting-up"
	class="external">Set up a device for development</a>.
	</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 class="devsite-terminal devsite-click-to-copy">
	export OUT_DIR_COMMON_BASE=<path-to-your-out-directory>
	</pre>
	<p>
	The output directory for each separate source tree will be named after the
	directory holding the source tree. 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. 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 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 <strong>New Image</strong>. 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
	<strong>case sensitive, journaled</strong> as the volume format.
	</p>
	<p>
	You can also create it from a shell with the following command:
	</p>
	<pre class="devsite-click-to-copy devsite-terminal" data-terminal-prefix="# ">
	hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 40g ~/android.dmg
	</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>
	<p>
	If you need a larger volume later, you can also resize the sparse image with
	the following command:
	</p>
	<pre class="devsite-click-to-copy devsite-terminal" data-terminal-prefix="# ">hdiutil resize -size <new-size-you-want>g ~/android.dmg.sparseimage
	</pre>
	<p>
	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>:
	</p>
	<ul>
	<li>To mount the image when you execute <code>mountAndroid</code>:
	<pre class="devsite-click-to-copy">
	# mount the android file image
	mountAndroid() { hdiutil attach ~/android.dmg -mountpoint /Volumes/android; }</pre>
	<aside class="note"><strong>Note:</strong> If your system created a
	<code>.dmg.sparseimage</code> file, replace <code>~/android.dmg</code> with
	<code>~/android.dmg.sparseimage</code>.
	</aside>
	</li>
	<li>To unmount it when you execute <code>umountAndroid</code>:
	<pre class="devsite-click-to-copy">
	# unmount the android file image
	umountAndroid() { hdiutil detach /Volumes/android; }</pre>
	</li>
	</ul>
	<p>
	After you've mounted the <code>android</code> volume, you'll do all your work
	there. You can eject it (unmount it) just as you would an external drive.
	</p>

	<h3 id="installing-the-mac-jdk">Installing the JDK</h3>
	<p>
	See <a href="requirements.html">Requirements</a> for the version of Java to
	use when developing various versions of Android.
	</p>

	<h4 id="installing-required-packages">Installing required packages</h4>
	<ol>
	<li>Install Xcode command line tools with:
	<pre class="devsite-terminal devsite-click-to-copy">
	xcode-select --install</pre>
	For older versions of Mac OS (10.8 or earlier), you must install Xcode from
	the <a href="http://developer.apple.com/" class="external">Apple developer
	site</a>. If you are not already registered as an Apple developer, you must
	must create an Apple ID to download.
	</li>
	<li>Install MacPorts from
	<a href="http://www.macports.org/install.php">macports.org</a>. Ensure
	<code>/opt/local/bin</code> appears in your path <strong>before</strong>
	<code>/usr/bin</code>. If not, add the following to your
	<code>~/.bash_profile</code> file:
	<pre class="devsite-click-to-copy">
	export PATH=/opt/local/bin:$PATH</pre>
	<aside class="note"><strong>Note:</strong> If you do not have a
	<code>.bash_profile</code> file in your home directory, create one.
	</aside>
	</li>
	<li>Get make, git, and GPG packages from MacPorts:
	<pre class="devsite-terminal devsite-click-to-copy">
	POSIXLY_CORRECT=1 sudo port install gmake libsdl git gnupg</pre>
	If using Mac OS X v10.4, also install bison:
	<pre class="devsite-terminal devsite-click-to-copy">
	POSIXLY_CORRECT=1 sudo port install bison</pre>
	</li>
	</ol>

	<h4 id="reverting-from-make-382">Reverting from make 3.82</h4>
	<p>
	In Android 4.0.x (Ice Cream Sandwich) and earlier, a bug exists in gmake 3.82
	that prevents Android from building. You can install version 3.81 using
	MacPorts with these steps:
	</p>
	<ol>
	<li>Edit <code>/opt/local/etc/macports/sources.conf</code> and add a line that
	says:
	<pre class="devsite-click-to-copy">
	file:///Users/Shared/dports</pre>
	above the rsync line. Then create this directory:
	<pre class="devsite-terminal devsite-click-to-copy">
	mkdir /Users/Shared/dports</pre>
	</li>
	<li>In the new <code>dports</code> directory, run:
	<pre class="devsite-terminal devsite-click-to-copy">
	svn co --revision 50980 http://svn.macports.org/repository/macports/trunk/dports/devel/gmake/ devel/gmake/</pre>
	</li>
	<li>Create a port index for your new local repository:
	<pre class="devsite-terminal devsite-click-to-copy">
	portindex /Users/Shared/dports</pre>
	</li>
	<li>Install the old version of gmake with:
	<pre class="devsite-terminal devsite-click-to-copy">
	sudo port install gmake @3.81</pre>
	</li>
	</ol>

	<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. To
	increase the cap, add the following lines to your
	<code>~/.bash_profile</code>:
	</p>
	<pre class="devsite-click-to-copy">
	# set the number of open files to be 1024
	ulimit -S -n 1024</pre>

	<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>

	</body>
	</html>