path: root/docs/html/guide/developing/tools/avd.jd

page.title=Android Virtual Devices
@jd:body

<div id="qv-wrapper">
<div id="qv">

  <h2>AVD quickview</h2>
  <ul>
    <li>You need to create an AVD to run any app in the Android emulator</li>
    <li>Each AVD is a completely independent virtual device, with its own
        hardware options, system image, and data storage.
    <li>You create AVD configurations to model different device environments 
        in the Android emulator.</li>
    <li>The <code>android</code> tool offers a graphical Android AVD 
        Manager and a command-line interface for creating AVDs.</li>
  </ul>
  <h2>In this document</h2>
  <ol>
    <li><a href="#creating">Creating an AVD</a>
      <ol>
        <li><a href="#listingtargets">Listing targets</a></li>
        <li><a href="#selectingtarget">Selecting a target</a></li>
        <li><a href="#createavd">Creating the AVD</a></li>
        <li><a href="#hardwareopts">Setting hardware emulation options</a></li>
        <li><a href="#location">Default location of the AVD files</a></li>
      </ol>
    </li>
    <li><a href="#managing">Managing AVDs</a>
      <ol>
        <li><a href="#moving">Moving an AVD</a></li>
        <li><a href="#updating">Updating an AVD</a></li>
        <li><a href="#deleting">Deleting an AVD</a></li>
      </ol>
    </li>
    <li><a href="#options">Command-line options</a></li>
  </ol>
  <h2>See Also</h2>
  <ol>
    <li><a href="{@docRoot}guide/developing/tools/emulator.html">Android 
        Emulator</a></li>
  </ol>
</div>
</div>

<p>Android Virtual Devices (AVDs) are configurations of emulator options that let
you better model an actual device.</p>

<p>Each AVD is made up of: </p>

<ul>
<li>A hardware profile.&nbsp;&nbsp;You can set options to define the hardware
features of the virtual device. For example, you can define whether the device
has a camera, whether it uses a physical QWERTY keyboard or a dialing pad, how
much memory it has, and so on. </li>
<li>A mapping to a system image.&nbsp;&nbsp;You can define what version of the
Android platform will run on the virtual device. You can choose a version of the
standard Android platform or the system image packaged with an SDK add-on.</li>
<li>Other options.&nbsp;&nbsp;You can specify the emulator skin you want to use
with the AVD, which lets you control the screen dimensions, appearance, and so
on. You can also specify the emulated SD card to use with the AVD.</li>
<li>A dedicated storage area on your development machine, in which is stored the
device's user data (installed applications, settings, and so on) and emulated SD
card.</li>
</ul>

<p>You can create as many AVDs as you need, based on the types of devices you
want to model and the Android platforms and external libraries you want to run
your application on. </p>

<p>In addition to the options in an AVD configuration, you can also
specify emulator command-line options at launch or by using the emulator
console to change behaviors or characteristics at run time. For a complete
reference of emulator options, please see the <a
href="{@docRoot}guide/developing/tools/emulator.html">Emulator</a>
documentation. </p>

<p>To create and manage AVDs, you use the <code>android</code> tool provided in
the <code>tools/</code> directory of the Android SDK. The tool provides both a
graphical AVD manager and a command-line interface that you can use to
create AVDs. To access the graphical AVD manager, run the
<code>android</code> tool without options. The sections below describe how to
use the <code>android</code> command-line interface to create and manage AVDs.
Note that some functionality, such as the capability to create an AVD with a
custom hardware configuration, are only available through the command-line
interface. </p>

<p>For more information about how to work with AVDs from inside your development
environment, see <a
href="{@docRoot}guide/developing/eclipse-adt.html">Developing in Eclipse with
ADT</a> or <a href="{@docRoot}guide/developing/other-ide.html">Developing in
Other IDEs</a>, as appropriate for your environment.</p>

<h2 id="creating">Creating an AVD</h2>

<div class="sidebox-wrapper">
<div class="sidebox-inner">
<p>The Android SDK does not include any preconfigured AVDs, so
you need to create an AVD before you can run any application in the emulator
(even the Hello World application).</p>
</div>
</div>

<p>To create an AVD, you use the <code>android</code> tool, a command-line
utility available in the <code>&lt;sdk&gt;/tools/</code> directory. Managing
AVDs is one of the two main function of the <code>android</code> tool (the other
is creating and updating Android projects). Open a terminal window and change to
the <code>&lt;sdk&gt;/tools/</code> directory, if needed</p>

<p>To create each AVD, you issue the command <code>android create avd</code>,
with options that specify a name for the new AVD and the system image you want
to run on the emulator when the AVD is invoked. You can specify other options on
the command line also, such as to create an emulated SD card for the new AVD, set
the emulator skin to use, or set a custom location for the AVD's files.</p>

<p>Here's the command-line usage for creating an AVD: </p>

<pre>android create avd -n &lt;name&gt; -t &lt;targetID&gt; [-&lt;option&gt; &lt;value&gt;] ... </pre>

<p>You can use any name you want for the AVD, but since you are likely to be
creating multiple AVDs, you should choose a name that lets you recognize the
general characteristics offered by the AVD. </p>

<p>As shown in the usage above, you must use the <code>-t</code> (or
<code>--target</code>) argument when creating a new AVD. The argument sets up a
mapping between the AVD and the system image that you want to use whenever the
AVD is invoked. You can specify any Android system image that is available in
your local SDK &mdash; it can be the system image of a standard Android platform
version or that of any SDK add-on. Later, when applications use the AVD, they'll
be running on the system that you specify in the <code>-t</code> argument.<p>

<p>To specify the system image to use, you refer to its <em>target ID</em>
&mdash; an integer &mdash; as assigned by the <code>android</code> tool. The
target ID is not derived from the system image name, version, or API Level, or
other attribute, so you need to have the <code>android</code> tool list the
available system images and the target ID of each, as described in the next
section. You should do this <em>before</em> you run the <code>android create
avd</code> command.
</p>

<h3 id="listingtargets">Listing targets</h3>

<p>To generate a list of system image targets, use this command: </p>

<pre>android list targets</pre>

<p>The <code>android</code> tool scans the <code>&lt;sdk&gt;/platforms</code> and
<code>&lt;sdk&gt;/add-ons</code> directories looking for valid system images and
then generates the list of targets. Here's an example of the command output:
</p>

<pre>Available Android targets:
id:1
    Name: Android 1.1
    Type: platform
    API level: 2
    Skins: HVGA (default), HVGA-L, HVGA-P, QVGA-L, QVGA-P
id:2
    Name: Android 1.5
    Type: platform
    API level: 3
    Skins: HVGA (default), HVGA-L, HVGA-P, QVGA-L, QVGA-P
id:3
    Name: Google APIs
    Type: add-on
    Vendor: Google Inc.
    Description: Android + Google APIs
    Based on Android 1.5 (API level 3)
    Libraries:
    * com.google.android.maps (maps.jar)
        API for Google Maps
    Skins: HVGA (default), HVGA-L, QVGA-P, HVGA-P, QVGA-L</pre>

<h3 id="selectingtarget">Selecting a target</h3>

<p>Once you have generated the list of targets available, you can look at the
characteristics of each system image &mdash; name, API Level, external
libraries, and so on &mdash; and determine which target is appropriate for the
new AVD. </p>

<p>Keep these points in mind when you are selecting a system image target for
your AVD:</p>
<ul>
<li>The API Level of the target is important, because your application will not
be able to run on a system image whose API Level is less than that required by
your application, as specified in the <code>minSdkVersion</code> attribute of
the application's manifest file. For more information about the relationship
between system API Level and application <code>minSdkVersion</code>, see <a
href="{@docRoot}guide/publishing/versioning.html#minsdkversion">Specifying
Minimum System API Version</a>.
<li>Creating at least one AVD that uses a target whose API Level is greater than
that required by your application is strongly encouraged, because it allows you to
test the forward-compatibility of your application. Forward-compatibility
testing ensures that, when users who have downloaded your application receive a
system update, your application will continue to function normally. </li>
<li>If your application declares a <code>uses-library</code> element in its
manifest file, the application can only run on a system image in which that
external library is present. If you want your application to run on the AVD you
are creating, check the application's <code>uses-library</code> element and
select a system image target that includes that library. 

</ul>

<h3 id="createavd">Creating the AVD</h3>

<p>When you've selected the target you want to use and made a note of its ID,
use the <code>android create avd</code> command to create the AVD, supplying the
target ID as the <code>-t</code> argument. Here's an example that creates an
AVD with name "my_android1.5" and target ID "2" (the standard Android 1.5 
system image in the list above): </p>

<pre>android create avd -n my_android1.5 -t 2</pre>

<p>If the target you selected was a standard Android system image ("Type:
platform"), the <code>android</code> tool next asks you whether you want to
create a custom hardware profile. </p>
<pre>Android 1.5 is a basic Android platform.
Do you wish to create a custom hardware profile [no]</pre>

<p>If you want to set custom hardware emulation options for the AVD, enter
"yes" and set values as needed. If you want to use the default hardware
emulation options for the AVD, just press the return key (the default is "no").
The <code>android</code> tool creates the AVD with name and system image mapping you
requested, with the options you specified. 

<p class="note">If you are creating an AVD whose target is an SDK add-on, the
<code>android</code> tool does not allow you to set hardware emulation options.
It assumes that the provider of the add-on has set emulation options
appropriately for the device that the add-on is modeling, and so prevents you
from resetting the options. </p>
<p>For a list of options you can use in the <code>android create avd</code>
command, see the table in <a href="#options">Command-line options for AVDs</a>,
at the bottom of
this page. </p>

<h3 id="hardwareopts">Setting hardware emulation options</h3>

<p>When are creating a new AVD that uses a standard Android system image ("Type:
platform"), the <code>android</code> tool lets you set hardware emulation
options for virtual device. The table below lists the options available and the
default values, as well as the names of properties that store the emulated
hardware options in the AVD's configuration file (the config.ini file in the
AVD's local directory). </p>

<table>
<tr>
<th>Characteristic</th>
<th>Description</th>
<th>Property</th>
</tr>

<tr>
<td>Device ram size</td>
<td>The amount of physical RAM on the device, in megabytes. Default value is "96".
<td>hw.ramSize</td>
</tr>

<tr>
<td>Touch-screen support</td>
<td>Whether there is a touch screen or not on the device. Default value is "yes".</td>
<td>hw.touchScreen

<tr>
<td>Trackball support </td>
<td>Whether there is a trackball on the device. Default value is "yes".</td>
<td>hw.trackBall</td>
</tr>

<tr>
<td>Keyboard support</td>
<td>Whether the device has a QWERTY keyboard. Default value is "yes".</td>
<td>hw.keyboard</td>
</tr>

<tr>
<td>DPad support</td>
<td>Whether the device has DPad keys. Default value is "yes".</td>
<td>hw.dPad</td>
</tr>

<tr>
<td>GSM modem support</td>
<td>Whether there is a GSM modem in the device. Default value is "yes".</td>
<td>hw.gsmModem</td>
</tr>

<tr>
<td>Camera support</td>
<td>Whether the device has a camera. Default value is "no".</td>
<td>hw.camera</td>
</tr>

<tr>
<td>Maximum horizontal camera pixels</td>
<td>Default value is "640".</td>
<td>hw.camera.maxHorizontalPixels</td>
</tr>

<tr>
<td>Maximum vertical camera pixels</td>
<td>Default value is "480".</td>
<td>hw.camera.maxVerticalPixels</td>
</tr>

<tr>
<td>GPS support</td>
<td>Whether there is a GPS in the device. Default value is "yes".</td>
<td>hw.gps</td>
</tr>

<tr>
<td>Battery support</td>
<td>Whether the device can run on a battery. Default value is "yes".</td>
<td>hw.battery</td>
</tr>

<tr>
<td>Accelerometer</td>
<td>Whether there is an accelerometer in the device. Default value is "yes".</td>
<td>hw.accelerometer</td>
</tr>

<tr>
<td>Audio recording support</td>
<td>Whether the device can record audio. Default value is "yes".</td>
<td>hw.audioInput</td>
</tr>

<tr>
<td>Audio playback support</td>
<td>Whether the device can play audio. Default value is "yes".</td>
<td>hw.audioOutput</td>
</tr>

<tr>
<td>SD Card support</td>
<td>Whether the device supports insertion/removal of virtual SD Cards. Default value is "yes".</td>
<td>hw.sdCard</td>
</tr>

<tr>
<td>Cache partition support</td>
<td>Whether we use a /cache partition on the device. Default value is "yes".</td>
<td>disk.cachePartition</td>
</tr>

<tr>
<td>Cache partition size</td>
<td>Default value is "66MB".</td>
<td>disk.cachePartition.size </td>
</tr>

<tr>
<td>Abstracted LCD density</td>
<td>Sets the generalized density characteristic used by the AVD's screen. Default value is "160".</td>
<td>hw.lcd.density </td>
</tr>

</table>

<h3 id="location">Default location of the AVD files</h3>

<p>When you create an AVD, the <code>android</code> tool creates a dedicated directory for it
on your development computer. The directory contains the AVD configuration file,
the user data image and SD card image (if available), and any other files
associated with the device. Note that the directory does not contain a system
image &mdash; instead, the AVD configuration file contains a mapping to the
system image, which it loads when the AVD is launched. </p>

<p>The <code>android</code> tool also creates a &lt;AVD name&gt;.ini file for the AVD at the
root of the .android/avd directory on your computer. The file specifies the
location of the AVD directory and always remains at the root the .android 
directory.</p>

<p>By default, the <code>android</code> tool creates the AVD directory inside
<code>~/.android/avd/</code> (on Linux/Mac), <code>C:\Documents and
Settings\&lt;user&gt;\.android\</code> on Windows XP, and 
<code>C:\Users\&lt;user&gt;\.android\</code> on Windows Vista. 
If you want to use a custom location for the AVD directory, you 
can do so by using the <code>-p &lt;path&gt;</code> option when 
you create the AVD: </p>

<pre>android create avd -n my_android1.5 -t 2 -p path/to/my/avd</pre>

<p>If the .android directory is hosted on a network drive, we recommend using
the <code>-p</code> option to place the AVD directory in another location. 
The  AVD's .ini file remains in the .android directory on the network
drive, regardless of the location of the AVD directory. </p>

<h2 id="managing">Managing AVDs</h2>

<p>The sections below provide more information about how to manage AVDs once you've created them. </p>

<h3 id="moving">Moving an AVD</h3>

<p>If you want to move or rename an AVD, you can do so using this command:</p>

<pre>android move avd -n &lt;name&gt; [-&lt;option&gt; &lt;value&gt;] ...</pre>

<p>The options for this command are listed in <a href="#options">Command-line
options for AVDs</a> at the bottom of this page. </p>

<h3 id="updating">Updating an AVD</h3>

<p>If, for any reason, the platform/add-on root folder has its name changed (maybe because the user has installed an update of the platform/add-on) then the AVD will not be able to load the system image that it is mapped to. In this case, the <code>android list targets</code> command will produce this output: 

<pre>The following Android Virtual Devices could not be loaded: 
Name: foo 
Path: &lt;path&gt;/.android/avd/foo.avd 
Error: Invalid value in image.sysdir. Run 'android update avd -n foo' </pre>

<p>To fix this error, use the <code>android update avd</code> command to recompute the path to the system images.</p>

<h3 id="deleting">Deleting an AVD</h3>

<p>You can use the <code>android</code> tool to delete an AVD. Here is the command usage:</p>

<pre>android delete avd -n &lt;name&gt; </pre>

<p>When you issue the command, the <code>android</code> tool looks for an AVD matching the 
specified name deletes the AVD's directory and files. </p>


<h2 id="options">Command-line options for AVDs</h2>

<p>The table below lists the command-line options you can use with the 
<code>android</code> tool. </p>


<table>
<tr>
  <th width="15%">Action</th>
  <th width="20%">Option</th>
  <th width="30%">Description</th>
  <th>Comments</th>
</tr>


<tr>
  <td><code>list&nbsp;avds</code></td>
  <td>&nbsp;</td>
  <td>List all known AVDs, with name, path, target, and skin. </td>
  <td>&nbsp;</td>
</tr>
<tr>
  <td rowspan="6"><code>create&nbsp;avd</code></td>
  <td><code>-n &lt;name&gt; or <br></code></td>
  <td>The name for the AVD.</td>
  <td>Required</td>
</tr>
<tr>
  <td><code>-t &lt;targetID&gt;</code></td>
  <td>Target ID of the system image to use with the new AVD.</td>
  <td>Required. To obtain a list of available targets, use <code>android list
      targets</code>.</td>
</tr>
<tr>
  <td><code>-c &lt;path&gt;</code> or <br>
      <code>-c &lt;size&gt;[K|M]</code></td>
  <td>The path to the SD card image to use with this AVD or the size of a new SD
      card image to create for this AVD.</td>
  <td>Examples: <code>-c path/to/sdcard</code> or <code>-c 1000M</code></td>
</tr>
<tr>
  <td><code>-f</code></td>
  <td>Force creation of the AVD</td>
  <td>By default, if the name of the AVD being created matches that of an 
      existing AVD, the <code>android</code> tool will not create the new AVD or overwrite 
      the existing AVD. If you specify the <code>-f</code> option, however, the 
      <code>android</code> tool will automatically overwrite any existing AVD that has the 
      same name as the new AVD. The files and data of the existing AVD are 
      deleted. </td>
</tr>

<tr>
  <td><code>-p &lt;path&gt;</code></td>
  <td>Path to the location at which to create the directory for this AVD's
files.</td>
  <td>&nbsp;</td>
</tr>
<tr>
  <td><code>-s &lt;name&gt;</code> or <br>
      <code>-s &lt;width&gt;-&lt;height&gt;</code> </td>
  <td>The skin to use for this AVD, identified by name or dimensions.</td>
  <td>The <code>android</code> tool scans for a matching skin by name or dimension in the
<code>skins/</code> directory of the target referenced in the <code>-t
&lt;targetID&gt;</code> argument. Example: <code>-s HVGA-L</code></td>
</tr>
<tr>
  <td><code>delete&nbsp;avd</code></td>
  <td><code>-n &lt;name&gt;</code></td>
  <td>Delete the specified AVD.</td>
  <td>Required</td>
</tr>
<tr>
  <td rowspan="3"><code>move&nbsp;avd</code></td>
  <td><code>-n &lt;name&gt;</code></td>
  <td>The name of the AVD to move.</td>
  <td>Required</td>
</tr>
<tr>
  <td><code>-p &lt;path&gt;</code></td>
  <td>The path to the new location for the AVD.</td>
  <td>&nbsp;</td>
</tr>
<tr>
  <td><code>-r &lt;new-name&gt;</code></td>
  <td>Rename the AVD.</td>
  <td>&nbsp;</td>
</tr>
<tr>
  <td><code>update&nbsp;avds</code></td>
  <td>&nbsp;</td>
  <td>Recompute the paths to all system images.</td>
  <td>&nbsp;</td>
</tr>



</table>