1page.title=Initializing a Build Environment
2@jd:body
3
4<!--
5    Copyright 2015 The Android Open Source Project
6
7    Licensed under the Apache License, Version 2.0 (the "License");
8    you may not use this file except in compliance with the License.
9    You may obtain a copy of the License at
10
11        http://www.apache.org/licenses/LICENSE-2.0
12
13    Unless required by applicable law or agreed to in writing, software
14    distributed under the License is distributed on an "AS IS" BASIS,
15    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16    See the License for the specific language governing permissions and
17    limitations under the License.
18-->
19<div id="qv-wrapper">
20  <div id="qv">
21    <h2>In this document</h2>
22    <ol id="auto-toc">
23    </ol>
24  </div>
25</div>
26
27<p>This section describes how to set up your local work environment to build
28the Android source files. You will need to use Linux or Mac OS. Building under
29Windows is not currently supported.</p>
30<p>For an overview of the entire code-review and code-update process, see <a
31href="life-of-a-patch.html">Life of a Patch</a>.</p>
32<h2 id="choosing-a-branch">Choosing a Branch</h2>
33<p>Some of the requirements for your build environment are determined by which
34version of the source code you plan to compile. See
35<a href="build-numbers.html">Build Numbers</a> for a full listing of branches you may
36choose from. You may also choose to download and build the latest source code
37(called <code>master</code>), in which case you will simply omit the branch specification
38when you initialize the repository.</p>
39<p>Once you have selected a branch, follow the appropriate instructions below to
40set up your build environment.</p>
41<h2 id="setting-up-a-linux-build-environment">Setting up a Linux build environment</h2>
42<p>These instructions apply to all branches, including <code>master</code>.</p>
43<p>The Android build is routinely tested in house on recent versions of
44Ubuntu LTS (14.04), but most distributions should have the required
45build tools available. Reports of successes or failures on other
46distributions are welcome.</p>
47<p>For Gingerbread (2.3.x) and newer versions, including the <code>master</code>
48branch, a 64-bit environment is required. Older versions can be
49compiled on 32-bit systems.</p>
50<p><strong>Note</strong>: See the <a href="building.html">Downloading and
51Building</a> page for the list of hardware and software requirements. Then
52follow the detailed instructions for Ubuntu and Mac OS below.</p>
53
54<h3 id="installing-the-jdk">Installing the JDK</h3>
55<p>The <code>master</code> branch of Android in the <a
56href="https://android.googlesource.com/">Android Open Source Project (AOSP)</a>
57requires Java 7. On Ubuntu, use <a href="http://openjdk.java.net/install/">OpenJDK</a>.</p>
58<p>Java 7: For the latest version of Android</p>
59<pre><code>$ sudo apt-get update
60$ sudo apt-get install openjdk-7-jdk
61</code></pre>
62
63<p>Optionally, update the default Java version by running:</p>
64<pre><code>$ sudo update-alternatives --config java
65$ sudo update-alternatives --config javac
66</code></pre>
67
68<p>If you encounter version errors for Java, set its
69path as described in the <a href="building-running.html#wrong-java-version">Wrong
70Java Version</a> section.</p>
71
72<p>To develop older versions of Android, download and install the corresponding version of the <a
73href="http://www.oracle.com/technetwork/java/javase/archive-139210.html">Java JDK</a>:<br/>
74Java 6: for Gingerbread through KitKat<br/>
75Java 5: for Cupcake through Froyo</p>
76
77<p><strong>Note</strong>: The <code>lunch</code> command in the build step will ensure that the Sun JDK is
78used instead of any previously installed JDK.</p>
79
80<h3 id="installing-required-packages-ubuntu-1404">Installing required packages (Ubuntu 14.04)</h3>
81<p>You will need a 64-bit version of Ubuntu. Ubuntu 14.04 is recommended.</p>
82<pre><code>$ sudo apt-get install bison g++-multilib git gperf libxml2-utils make zlib1g-dev:i386 zip</code></pre>
83
84<h3 id="installing-required-packages-ubuntu-1204">Installing required packages (Ubuntu 12.04)</h3>
85<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>
86<pre><code>$ sudo apt-get install git gnupg flex bison gperf build-essential \
87  zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \
88  libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \
89  libgl1-mesa-dev g++-multilib mingw32 tofrodos \
90  python-markdown libxml2-utils xsltproc zlib1g-dev:i386
91$ sudo ln -s /usr/lib/i386-linux-gnu/mesa/libGL.so.1 /usr/lib/i386-linux-gnu/libGL.so
92</code></pre>
93
94<h3 id="installing-required-packages-ubuntu-1004-1110">Installing required packages (Ubuntu 10.04 -- 11.10)</h3>
95<p>Building on Ubuntu 10.04-11.10 is no longer supported, but may be useful for building older
96releases of AOSP.</p>
97<pre><code>$ sudo apt-get install git gnupg flex bison gperf build-essential \
98  zip curl zlib1g-dev libc6-dev lib32ncurses5-dev ia32-libs \
99  x11proto-core-dev libx11-dev lib32readline5-dev lib32z-dev \
100  libgl1-mesa-dev g++-multilib mingw32 tofrodos python-markdown \
101  libxml2-utils xsltproc
102</code></pre>
103<p>On Ubuntu 10.10:</p>
104<pre><code>$ sudo ln -s /usr/lib32/mesa/libGL.so.1 /usr/lib32/mesa/libGL.so
105</code></pre>
106<p>On Ubuntu 11.10:</p>
107<pre><code>$ sudo apt-get install libx11-dev:i386
108</code></pre>
109<h3 id="configuring-usb-access">Configuring USB Access</h3>
110<p>Under GNU/Linux systems (and specifically under Ubuntu systems),
111regular users can't directly access USB devices by default. The
112system needs to be configured to allow such access.</p>
113<p>The recommended approach is to create a file
114<code>/etc/udev/rules.d/51-android.rules</code> (as the root user) and to copy
115the following lines in it. <code>&lt;username&gt;</code> must be replaced by the
116actual username of the user who is authorized to access the phones
117over USB.</p>
118<pre><code># adb protocol on passion (Nexus One)
119SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e12", MODE="0600", OWNER="&lt;username&gt;"
120# fastboot protocol on passion (Nexus One)
121SUBSYSTEM=="usb", ATTR{idVendor}=="0bb4", ATTR{idProduct}=="0fff", MODE="0600", OWNER="&lt;username&gt;"
122# adb protocol on crespo/crespo4g (Nexus S)
123SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e22", MODE="0600", OWNER="&lt;username&gt;"
124# fastboot protocol on crespo/crespo4g (Nexus S)
125SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e20", MODE="0600", OWNER="&lt;username&gt;"
126# adb protocol on stingray/wingray (Xoom)
127SUBSYSTEM=="usb", ATTR{idVendor}=="22b8", ATTR{idProduct}=="70a9", MODE="0600", OWNER="&lt;username&gt;"
128# fastboot protocol on stingray/wingray (Xoom)
129SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="708c", MODE="0600", OWNER="&lt;username&gt;"
130# adb protocol on maguro/toro (Galaxy Nexus)
131SUBSYSTEM=="usb", ATTR{idVendor}=="04e8", ATTR{idProduct}=="6860", MODE="0600", OWNER="&lt;username&gt;"
132# fastboot protocol on maguro/toro (Galaxy Nexus)
133SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e30", MODE="0600", OWNER="&lt;username&gt;"
134# adb protocol on panda (PandaBoard)
135SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d101", MODE="0600", OWNER="&lt;username&gt;"
136# adb protocol on panda (PandaBoard ES)
137SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="d002", MODE="0600", OWNER="&lt;username&gt;"
138# fastboot protocol on panda (PandaBoard)
139SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d022", MODE="0600", OWNER="&lt;username&gt;"
140# usbboot protocol on panda (PandaBoard)
141SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d00f", MODE="0600", OWNER="&lt;username&gt;"
142# usbboot protocol on panda (PandaBoard ES)
143SUBSYSTEM=="usb", ATTR{idVendor}=="0451", ATTR{idProduct}=="d010", MODE="0600", OWNER="&lt;username&gt;"
144# adb protocol on grouper/tilapia (Nexus 7)
145SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e42", MODE="0600", OWNER="&lt;username&gt;"
146# fastboot protocol on grouper/tilapia (Nexus 7)
147SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4e40", MODE="0600", OWNER="&lt;username&gt;"
148# adb protocol on manta (Nexus 10)
149SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4ee2", MODE="0600", OWNER="&lt;username&gt;"
150# fastboot protocol on manta (Nexus 10)
151SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", ATTR{idProduct}=="4ee0", MODE="0600", OWNER="&lt;username&gt;"
152</code></pre>
153<p>Those new rules take effect the next time a device is plugged in.
154It might therefore be necessary to unplug the device and plug it
155back into the computer.</p>
156<p>This is known to work on both Ubuntu Hardy Heron (8.04.x LTS) and
157Lucid Lynx (10.04.x LTS). Other versions of Ubuntu or other
158variants of GNU/Linux might require different configurations.</p>
159<h3 id="using-a-separate-output-directory">Using a separate output directory</h3>
160<p>By default, the output of each build is stored in the <code>out/</code>
161subdirectory of the matching source tree.</p>
162<p>On some machines with multiple storage devices, builds are
163faster when storing the source files and the output on
164separate volumes. For additional performance, the output
165can be stored on a filesystem optimized for speed instead
166of crash robustness, since all files can be re-generated
167in case of filesystem corruption.</p>
168<p>To set this up, export the <code>OUT_DIR_COMMON_BASE</code> variable
169to point to the location where your output directories
170will be stored.</p>
171<pre><code>export OUT_DIR_COMMON_BASE=&lt;path-to-your-out-directory&gt;
172</code></pre>
173<p>The output directory for each separate source tree will be
174named after the directory holding the source tree.</p>
175<p>For instance, if you have source trees as <code>/source/master1</code>
176and <code>/source/master2</code> and <code>OUT_DIR_COMMON_BASE</code> is set to
177<code>/output</code>, the output directories will be <code>/output/master1</code>
178and <code>/output/master2</code>.</p>
179<p>It's important in that case to not have multiple source
180trees stored in directories that have the same name,
181as those would end up sharing an output directory, with
182unpredictable results.</p>
183<p>This is only supported on Jelly Bean (4.1) and newer,
184including the <code>master</code> branch.</p>
185<h2 id="setting-up-a-mac-os-x-build-environment">Setting up a Mac OS build environment</h2>
186<p>In a default installation, Mac OS runs on a case-preserving but case-insensitive
187filesystem. This type of filesystem is not supported by git and will cause some
188git commands (such as <code>git status</code>) to behave abnormally. Because of this, we
189recommend that you always work with the AOSP source files on a case-sensitive
190filesystem. This can be done fairly easily using a disk image, discussed below.</p>
191<p>Once the proper filesystem is available, building the <code>master</code> branch in a modern
192Mac OS environment is very straightforward. Earlier branches, including ICS,
193require some additional tools and SDKs.</p>
194<h3 id="creating-a-case-sensitive-disk-image">Creating a case-sensitive disk image</h3>
195<p>You can create a case-sensitive filesystem within your existing Mac OS environment
196using a disk image. To create the image, launch Disk
197Utility and select "New Image".  A size of 25GB is the minimum to
198complete the build; larger numbers are more future-proof. Using sparse images
199saves space while allowing to grow later as the need arises. Be sure to select
200"case sensitive, journaled" as the volume format.</p>
201<p>You can also create it from a shell with the following command:</p>
202<pre><code># hdiutil create -type SPARSE -fs 'Case-sensitive Journaled HFS+' -size 40g ~/android.dmg
203</code></pre>
204<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.
205<p>If you need a larger volume later, you can also resize the sparse image with the following command:</p>
206<pre><code># hdiutil resize -size &lt;new-size-you-want&gt;g ~/android.dmg.sparseimage
207</code></pre>
208For a disk image named <code>android.dmg</code> stored in your home directory, you can add helper functions to your <code>~/.bash_profile</code>:
209<ul>
210<li>
211To mount the image when you execute <code>mountAndroid</code>:</p>
212<pre><code># mount the android file image
213function mountAndroid { hdiutil attach ~/android.dmg -mountpoint /Volumes/android; }
214</code></pre>
215<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>
216</li>
217<li>
218<p>To unmount it when you execute <code>umountAndroid</code>:</p>
219<pre><code># unmount the android file image
220function umountAndroid() { hdiutil detach /Volumes/android; }
221</code></pre>
222</li>
223</ul>
224<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>
225
226<h3 id="installing-the-mac-jdk">Installing the JDK</h3>
227<p>The <code>master</code> and <code>5.0.x</code> branches of Android in the <a
228href="https://android.googlesource.com/">Android Open Source Project (AOSP)</a>
229require Java 7. On Mac OS, use <a
230href="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>
231
232<p>To develop for versions of Android Gingerbread through KitKat, download and
233install the Java 6 version of the <a
234href="http://support.apple.com/kb/dl1572">Java JDK</a>.</p>
235
236<h3 id="master-branch">Master branch</h3>
237<p>To build the latest source in a Mac OS environment, you will need an Intel/x86
238machine running Mac OS X v10.8 (Mountain Lion) or later, along with Xcode
2394.5.2 or later including the Command Line Tools.</p>
240
241<h3 id="branch-50x-and-all-earlier-branches">Branch 5.0.x and earlier branches</h3>
242<p>To build 5.0.x and earlier source in a Mac OS environment, you will need an Intel/x86
243machine running Mac OS X v10.8 (Mountain Lion), along with Xcode
2444.5.2 and Command Line Tools.</p>
245
246<h3 id="branch-44x-and-all-earlier-branches">Branch 4.4.x and earlier branches</h3>
247<p>To build 4.2.x and earlier source in a Mac OS environment, you will need an Intel/x86
248machine running Mac OS X v10.6 (Snow Leopard) or Mac OS X v10.7 (Lion), along with Xcode
2494.2 (Apple's Developer Tools). Although Lion does not come with a JDK, it should
250install automatically when you attempt to build the source.</p>
251<p>The remaining sections for Mac OS apply only to those who wish to build
252earlier branches.</p>
253
254<h3 id="branch-40x-and-all-earlier-branches">Branch 4.0.x and all earlier branches</h3>
255<p>To build android-4.0.x and earlier branches in a Mac OS environment, you need an
256Intel/x86 machine running Mac OS X v10.5 (Leopard) or Mac OS X v10.6 (Snow Leopard). You
257will need the Mac OS X v10.5 SDK.</p>
258<h4 id="installing-required-packages">Installing required packages</h4>
259<ul>
260<li>
261<p>Install Xcode from <a href="http://developer.apple.com/">the Apple developer site</a>.
262We recommend version 3.1.4 or newer (e.g., gcc 4.2).
263Version 4.x could cause difficulties.
264If you are not already registered as an Apple developer, you will have to
265create an Apple ID in order to download.</p>
266</li>
267<li>
268<p>Install MacPorts from <a href="http://www.macports.org/install.php">macports.org</a>.</p>
269<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>
270<pre><code>export PATH=/opt/local/bin:$PATH
271</code></pre>
272<p><em>to your <code>~/.bash_profile</code>.</em></p>
273
274<p><strong>Note</strong>: If you do not have a <code>.bash_profile</code> file in your home directory, create one.</p>
275
276</li>
277<li>
278<p>Get make, git, and GPG packages from MacPorts: </p>
279<pre><code>$ POSIXLY_CORRECT=1 sudo port install gmake libsdl git gnupg
280</code></pre>
281<p>If using Mac OS X v10.4, also install bison:</p>
282<pre><code>$ POSIXLY_CORRECT=1 sudo port install bison
283</code></pre>
284</li>
285</ul>
286<h4 id="reverting-from-make-382">Reverting from make 3.82</h4>
287<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>
288<ul>
289<li>
290<p>Edit <code>/opt/local/etc/macports/sources.conf</code> and add a line that says</p>
291<pre><code>file:///Users/Shared/dports
292</code></pre>
293<p>above the rsync line.  Then create this directory: </p>
294<pre><code>$ mkdir /Users/Shared/dports
295</code></pre>
296</li>
297<li>
298<p>In the new <code>dports</code> directory, run </p>
299<pre><code>$ svn co --revision 50980 http://svn.macports.org/repository/macports/trunk/dports/devel/gmake/ devel/gmake/
300</code></pre>
301</li>
302<li>
303<p>Create a port index for your new local repository: </p>
304<pre><code>$ portindex /Users/Shared/dports
305</code></pre>
306</li>
307<li>
308<p>Finally, install the old version of gmake with </p>
309<pre><code>$ sudo port install gmake @3.81
310</code></pre>
311</li>
312</ul>
313<h4 id="setting-a-file-descriptor-limit">Setting a file descriptor limit</h4>
314<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 />
315</p>
316<p>To increase the cap, add the following lines to your <code>~/.bash_profile</code>: </p>
317<pre><code># set the number of open files to be 1024
318ulimit -S -n 1024
319</code></pre>
320<h2 id="optimizing-a-build-environment">Optimizing a build environment (optional)</h2>
321<p><a name="ccache"></a></p>
322<h3 id="setting-up-ccache">Setting up ccache</h3>
323<p>You can optionally tell the build to use the ccache compilation tool.
324Ccache acts as a compiler cache that can be used to speed up rebuilds.
325This works very well if you use <code>make clean</code> often, or if you frequently
326switch between different build products.</p>
327<p>Put the following in your <code>.bashrc</code> (or equivalent):</p>
328<pre><code>export USE_CCACHE=1
329</code></pre>
330<p>By default the cache will be stored in <code>~/.ccache</code>.
331If your home directory is on NFS or some other non-local filesystem,
332you will want to specify the directory in your <code>.bashrc</code> file as well:</p>
333<pre><code>export CCACHE_DIR=&lt;path-to-your-cache-directory&gt;
334</code></pre>
335<p>The suggested cache size is 50-100GB.
336You will need to run the following command once you have downloaded
337the source code:</p>
338<pre><code>prebuilts/misc/linux-x86/ccache/ccache -M 50G
339</code></pre>
340<p>On Mac OS, you should replace <code>linux-x86</code> with <code>darwin-x86</code>:</p>
341<pre><code>prebuilts/misc/darwin-x86/ccache/ccache -M 50G
342</code></pre>
343<p>When building Ice Cream Sandwich (4.0.x) or older, ccache is in
344a different location:</p>
345<pre><code>prebuilt/linux-x86/ccache/ccache -M 50G
346</code></pre>
347<p>This setting is stored in the CCACHE_DIR and is persistent.</p>
348<h2 id="next-download-the-source">Next: Download the source</h2>
349<p>Your build environment is good to go! Proceed to <a href="downloading.html">downloading the source</a>.</p>
350