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      1 page.title=Using the Emulator
      2 @jd:body
      3 
      4 <div id="qv-wrapper">
      5 <div id="qv">
      6 
      7   <h2>In this document</h2>
      8     <ol>
      9       <li><a href="#overview">Overview</a></li>
     10       <li><a href="#avds">Android Virtual Devices and the Emulator</a></li>
     11       <li><a href="#starting">Starting and Stopping the Emulator</a></li>
     12       <li><a href="#apps">Installing Applications on the Emulator</a></li>
     13       <li><a href="#acceleration">Using Hardware Acceleration</a>
     14         <ol>
     15           <li><a href="#accel-graphics">Configuring Graphics Acceleration</a></li>
     16           <li><a href="#accel-vm">Configuring Virtual Machine Acceleration</a></li>
     17         </ol>
     18       </li>
     19       <li><a href="#sdcard">SD Card Emulation</a>
     20         <ol>
     21           <li><a href="#sdcard-creating">Creating an SD card image</a></li>
     22           <li><a href="#sdcard-files">Copying files to an SD card image</a></li>
     23           <li><a href="#sdcard-loading">Loading an SD card image</a></li>
     24         </ol>
     25       </li>
     26       <li><a href="#diskimages">Working with Emulator Disk Images</a>
     27 	      <ol>
     28 	        <li><a href="#defaultimages">Default image files</a></li>
     29 	        <li><a href="#runtimeimages">Runtime images: user data and SD card</a></li>
     30 	        <li><a href="#temporaryimages">Temporary images</a></li>
     31 	      </ol>
     32 	    </li>
     33       <li><a href="#emulatornetworking">Emulator Networking</a>
     34 	      <ol>
     35           <li><a href="#networkaddresses">Network Address Space</a></li>
     36           <li><a href="#networkinglimitations">Local Networking Limitations</a></li>
     37           <li><a href="#redirection">Using Network Redirection</a></li>
     38           <li><a href="#dns">Configuring the Emulator's DNS Settings</a></li>
     39           <li><a href="#proxy">Using the Emulator with a Proxy</a></li>
     40           <li><a href="#connecting">Interconnecting Emulator Instances</a></li>
     41           <li><a href="#calling">Sending a Voice Call or SMS to Another Emulator Instance</a></li>
     42         </ol>
     43       </li>
     44       <li><a href="#console">Using the Emulator Console</a>
     45         <ol>
     46           <li><a href="#portredirection">Port Redirection</a></li>
     47           <li><a href="#geo">Geo Location Provider Emulation</a></li>
     48           <li><a href="#events">Hardware Events Emulation</a></li>
     49           <li><a href="#power">Device Power Characteristics</a></li>
     50           <li><a href="#netstatus">Network Status</a></li>
     51           <li><a href="#netdelay">Network Delay Emulation</a></li>
     52           <li><a href="#netspeed">Network Speed Emulation</a></li>
     53           <li><a href="#telephony">Telephony Emulation</a></li>
     54           <li><a href="#sms">SMS Emulation</a></li>
     55           <li><a href="#vm">VM State</a></li>
     56           <li><a href="#window">Emulator Window</a></li>
     57           <li><a href="#terminating">Terminating an Emulator Instance</a></li>
     58         </ol>
     59       </li>
     60       <li><a href="#limitations">Emulator Limitations</a></li>
     61       <li><a href="#troubleshooting">Troubleshooting Emulator Problems</a></li>
     62     </ol>
     63 
     64   <h2>See also</h2>
     65   <ol>
     66     <li><a href="{@docRoot}tools/help/emulator.html">Android Emulator</a></li>
     67     <li><a href="{@docRoot}tools/devices/managing-avds.html">Managing AVDs with AVD Manager</a></li>
     68   </ol>
     69 </div>
     70 </div>
     71 
     72 <p>The Android SDK includes a virtual mobile device emulator
     73 that runs on your computer. The emulator lets you prototype, develop and test
     74 Android applications without using a physical device. </p>
     75 
     76 <p>The Android emulator mimics all of the hardware and software features
     77 of a typical mobile device, except that it cannot place actual phone
     78 calls. It provides a variety of navigation and control keys, which you can "press"
     79 using your mouse or keyboard to generate events for your application. It also
     80 provides a screen in which your application is displayed, together with any other
     81 active Android applications. </p>
     82 
     83 <img src="{@docRoot}images/emulator@2x.png"
     84 srcset="{@docRoot}images/emulator.png 1x, {@docRoot}images/emulator@2x.png 2x" alt=""
     85   width="367" height="330"/>
     86 
     87 <p>To let you model and test your application more easily, the emulator utilizes
     88 Android Virtual Device (AVD) configurations. AVDs let you define certain hardware
     89 aspects of your emulated phone and allow you to create many configurations to test
     90 many Android platforms and hardware permutations. Once your application is running on
     91 the emulator, it can use the services of the Android platform to invoke other
     92 applications, access the network, play audio and video, store and retrieve data,
     93 notify the user, and render graphical transitions and themes. </p>
     94 
     95 <p>The emulator also includes a variety of debug capabilities, such as a console
     96 from which you can log kernel output, simulate application interrupts (such as
     97 arriving SMS messages or phone calls), and simulate latency effects and dropouts
     98 on the data network.</p>
     99 
    100 
    101 
    102 <h2 id="overview">Overview</h2>
    103 
    104 <p>The Android emulator is an application that provides a virtual
    105 mobile device on which you can run your Android applications. It runs a full
    106 Android system stack, down to the kernel level, that includes a set of
    107 preinstalled applications (such as the dialer) that you can access from your
    108 applications. You can choose what version of the Android system you want to
    109 run in the emulator by configuring AVDs, and you can also customize the
    110 mobile device skin and key mappings. When launching the emulator and at runtime,
    111 you can use a variety of commands and options to control its behavior.
    112 </p>
    113 
    114 <p>The Android system images available through the Android SDK Manager contain
    115 code for the Android Linux kernel, the native libraries, the Dalvik VM, and the
    116 various Android packages (such as the Android framework and preinstalled
    117 applications). The emulator provides dynamic binary translation of device
    118 machine code to the OS and processor architecture of your development
    119 machine.</p>
    120 
    121 <p>The Android emulator supports many hardware features likely to be found on
    122 mobile devices, including: </p>
    123 
    124 <ul>
    125   <li>An ARMv5, ARMv7, or x86 CPU</li>
    126   <li>A 16-bit LCD display</li>
    127   <li>One or more keyboards (a Qwerty-based keyboard and associated Dpad/Phone
    128 buttons)</li>
    129   <li>A sound chip with output and input capabilities</li>
    130   <li>Flash memory partitions (emulated through disk image files on the
    131 development machine)</li>
    132   <li>A GSM modem, including a simulated SIM Card</li>
    133   <li>A camera, using a webcam connected to your development computer.</li>
    134   <li>Sensors like an accelerometer, using data from a USB-connected Android device.</li>
    135 </ul>
    136 
    137 <p>The following sections describe the emulator and its use for development of Android
    138 applications in more detail.</p>
    139 
    140 
    141 <h2 id="avds">Android Virtual Devices and the Emulator</h2>
    142 
    143 <p>To use the emulator, you first must create one or more AVD configurations. In each
    144 configuration, you specify an Android platform to run in the emulator and the set of hardware
    145 options and emulator skin you want to use. Then, when you launch the emulator, you specify
    146 the AVD configuration that you want to load. </p>
    147 
    148 <p>Each AVD functions as an independent device, with its own private storage for
    149 user data, SD card, and so on. When you launch the emulator with an AVD configuration,
    150 it automatically loads the user data and SD card data from the AVD directory. By default,
    151 the emulator stores the user data, SD card data, and cache in the AVD directory.</p>
    152 
    153 <p>To create and manage AVDs you use the AVD Manager UI or the <code>android</code> tool
    154 that is included in the SDK.
    155 For complete information about how to set up AVDs, see <a
    156 href="{@docRoot}tools/devices/index.html">Managing Virtual Devices</a>.</p>
    157 
    158 
    159 <h2 id="starting">Starting and Stopping the Emulator</h2>
    160 
    161 <p>During development and testing of your application, you install and run your
    162 application in the Android emulator. You can launch the emulator as a standalone
    163 application from a command line, or you can run it from within your Android Studio
    164 development environment. In either case, you specify the AVD configuration to
    165 load and any startup options you want to use, as described in this document.
    166 </p>
    167 
    168 <p>You can run your application on a single instance of the emulator or,
    169 depending on your needs, you can start multiple emulator instances and run your
    170 application in more than one emulated device. You can use the emulator's
    171 built-in commands to simulate GSM phone calling or SMS between emulator
    172 instances, and you can set up network redirection that allows emulators to send
    173 data to one another. For more information, see <a href="#telephony">Telephony
    174 Emulation</a>, <a href="#sms">SMS Emulation</a>, and
    175 <a href="#emulatornetworking">Emulator Networking</a></p>
    176 
    177 <p>To start an instance of the emulator from the command line, navigate to the
    178 <code>tools/</code> folder of the SDK. Enter <code>emulator</code> command
    179 like this: </p>
    180 
    181 <pre>emulator -avd &lt;avd_name&gt; [&lt;options&gt;]</pre>
    182 
    183 <p>This initializes the emulator, loads an AVD configuration and displays the emulator
    184 window. For more information about command line options for the emulator, see the
    185 <a href="{@docRoot}tools/help/emulator.html">Android Emulator</a> tool reference.</p>
    186 
    187 <p class="note"><strong>Note:</strong> You can run multiple
    188 instances of the emulator concurrently, each with its own AVD configuration and
    189 storage area for user data, SD card, and so on.</p>
    190 
    191 <p>When you run your app from Android Studio, it installs and launches the
    192 app on your connected device or emulator (launching the emulator, if necessary).
    193 You can specify emulator startup options in the Run/Debug
    194 dialog, in the Target tab. When the emulator is running, you can issue
    195 console commands as described later in this document.</p>
    196 
    197 <p>If you are not working in Android Studio, see <a href="#apps">Installing Applications
    198 on the Emulator</a> for information about how to install your application.</p>
    199 
    200 <p>To stop an emulator instance, just close the emulator's window.</p>
    201 
    202 <p>For a reference of the emulator's startup commands and keyboard mapping, see
    203 the <a href="{@docRoot}tools/help/emulator.html">Android Emulator</a> tool
    204 reference.</p>
    205 
    206 
    207 <h2 id="apps">Installing Applications on the Emulator</h2>
    208 
    209 <p>If you don't have access to Android Studio, you can install your application on the
    210 emulator using the <a href="{@docRoot}tools/help/adb.html#move">adb</a> utility. Before
    211 installing the application, you need to build and package it into an <code>.apk</code> as described
    212 in <a href="{@docRoot}tools/building/index.html">Building and
    213 Running Apps</a>. Once the application is installed, you can start the emulator from the command
    214 line as described previously, using any startup options necessary.
    215 When the emulator is running, you can also connect to the emulator instance's
    216 <a href="#console">console</a> to issue commands as needed.</p>
    217 
    218 <p>As you update your code, you periodically package and install it on the emulator.
    219 The emulator preserves the application and its state data across restarts,
    220 in a user-data disk partition. To ensure that the application runs properly
    221 as you update it, you may need to delete the emulator's user-data partition.
    222 To do so, start the emulator with the <code>-wipe-data</code> option.
    223 For more information about the user-data partition and other emulator storage,
    224 see <a href="#diskimages">Working with Emulator Disk Images</a>.</p>
    225 
    226 
    227 <h2 id="acceleration">Using Hardware Acceleration</h2>
    228 
    229 <p>In order to make the Android emulator run faster and be more responsive, you can configure it to
    230 take advantage of hardware acceleration, using a combination of configuration options, specific
    231 Android system images and hardware drivers.</p>
    232 
    233 
    234 <h3 id="accel-graphics">Configuring Graphics Acceleration</h3>
    235 
    236 <p class="caution"><strong>Caution:</strong> As of SDK Tools Revision 17, the graphics
    237 acceleration feature for the emulator is experimental; be alert for incompatibilities and
    238 errors when using this feature. </p>
    239 
    240 <p>Graphics acceleration for the emulator takes advantage of your development computer's graphics
    241 hardware, specifically its graphics processing unit (GPU), to make screen drawing faster. To use
    242 the graphics acceleration feature, you must have the following versions of the Android development
    243 tools installed:</p>
    244 
    245 <ul>
    246   <li>Android SDK Tools, Revision 17 or higher</li>
    247   <li>Android SDK Platform API 15, Revision 3 or higher</li>
    248 </ul>
    249 
    250 <p>Use the <a href="{@docRoot}sdk/installing/index.html#AddingComponents">Android SDK
    251 Manager</a> to install these components:</p>
    252 
    253 <p class="note"><strong>Note:</strong> Not all applications are compatible with graphics hardware
    254 acceleration. In particular, the Browser application and applications using the {@link
    255 android.webkit.WebView} component are not compatible with graphics acceleration.</p>
    256 
    257 <p>To configure an AVD to use graphics acceleration:</p>
    258 
    259 <ol>
    260   <li>Make sure you have the required SDK components installed (listed above).</li>
    261   <li>Start the AVD Manager and create a new AVD with the <strong>Target</strong> value of
    262 <strong>Android 4.0.3 (API Level 15)</strong>, revision 3 or higher.</li>
    263   <li>If you want to have graphics acceleration enabled by default for this AVD, in the
    264 <strong>Hardware</strong> section, click <strong>New</strong>, select <strong>GPU emulation</strong>
    265 and set the value to <strong>Yes</strong>.
    266   <p class="note"><strong>Note:</strong> You can also enable graphics acceleration when you
    267 start an emulator using command line options as describe in the next section.</p>
    268   </li>
    269   <li>Name the AVD instance and select any other configuration options.
    270   <p class="caution"><strong>Caution:</strong> Do not select the <strong>Snapshot: Enabled</strong>
    271 option. Snapshots are not supported for emulators with graphics acceleration enabled.</p>
    272   </li>
    273   <li>Click <strong>Create AVD</strong> to save the emulator configuration.</li>
    274 </ol>
    275 
    276 <p>If you set <strong>GPU emulation</strong> to <strong>Yes</strong> for your AVD, then graphics
    277 acceleration is automatically enabled when you run it. If you did not enable <strong>GPU
    278 emulation</strong> when you created the AVD, you can still enable it at runtime.</p>
    279 
    280 <p>To enable graphics acceleration at runtime for an AVD:</p>
    281 
    282 <ul>
    283   <li>If you are running the emulator from the command line, just include the {@code -gpu on}
    284 option:
    285 <pre>emulator -avd &lt;avd_name&gt; -gpu on</pre>
    286     <p class="note"><strong>Note:</strong> You must specify an AVD configuration that uses
    287 Android 4.0.3 (API Level 15, revision 3) or higher system image target. Graphics acceleration is not
    288 available for earlier system images.</p>
    289   </li>
    290   <li>If you are running the emulator from Android Studio, run your Android application using an AVD
    291 with the {@code -gpu on} option enabled:
    292     <ol>
    293       <li>In Android Studio, click your Android application module folder and then select
    294       <strong>Run > Edit Configurations...</strong></li>
    295       <li>In the left panel of the <strong>Run/Debug Configurations</strong> dialog, select your Android
    296       run configuration or create a new configuration.</li>
    297       <li>Under the <strong>Target Device </strong> options,
    298       select the AVD you created in the previous procedure.</li>
    299       <li>In the <strong>Emulator</strong> tab, in the
    300       <strong>Additional command line options</strong> field, enter:<br>
    301         {@code -gpu on}</li>
    302       <li>Run your Android project using this run configuration.</li>
    303     </ol>
    304   </li>
    305 </ul>
    306 
    307 
    308 <h3 id="accel-vm">Configuring Virtual Machine Acceleration</h2>
    309 
    310 <p class="caution"><strong>Caution:</strong> As of SDK Tools Revision 17, the virtual machine
    311 acceleration feature for the emulator is experimental; be alert for incompatibilities and errors
    312 when using this feature.</p>
    313 
    314 <p>Many modern CPUs provide extensions for running virtual machines (VMs) more efficiently. Taking
    315 advantage of these extensions with the Android emulator requires some additional configuration of
    316 your development system, but can significantly improve the execution speed. Before attempting to use
    317 this type of acceleration, you should first determine if your development systems CPU supports one
    318 of the following virtualization extensions technologies:</p>
    319 
    320 <ul>
    321   <li>Intel Virtualization Technology (VT, VT-x, vmx) extensions</li>
    322   <li>AMD Virtualization (AMD-V, SVM) extensions (only supported for Linux)</li>
    323 </ul>
    324 
    325 <p>The specifications from the manufacturer of your CPU should indicate if it supports
    326 virtualization extensions. If your CPU does not support one of these virtualization technologies,
    327 then you cannot use virtual machine acceleration.</p>
    328 
    329 <p class="note"><strong>Note:</strong> Virtualization extensions are typically enabled through
    330 your computer's BIOS and are frequently turned off by default. Check the documentation for your
    331 system's motherboard to find out how to enable virtualization extensions.</p>
    332 
    333 <p>Once you have determined that your CPU supports virtualization extensions, make sure you can work
    334 within these additional requirements of running an emulator inside an accelerated virtual
    335 machine:</p>
    336 
    337 <ul>
    338   <li><strong>x86 AVD Only</strong> - You must use an AVD that is uses an x86 system image target.
    339 AVDs that use ARM-based system images cannot be accelerated using the emulator configurations
    340 described here.</li>
    341   <li><strong>Not Inside a VM</strong> - You cannot run a VM-accelerated emulator inside another
    342 virtual machine, such as a VirtualBox or VMWare-hosted virtual machine. You must run the emulator
    343 directly on your system hardware.</li>
    344   <li><strong>Other VM Drivers</strong> - If you are running another virtualization technology on
    345 your system such as VirtualBox or VMWare, you may need to unload the driver for that virtual machine
    346 hosting software before running an accelerated emulator.</li>
    347   <li><strong>OpenGL&reg; Graphics</strong> - Emulation of OpenGL ES graphics may not perform at the
    348 same level as an actual device.</li>
    349 </ul>
    350 
    351 <p>To use virtual machine acceleration with the emulator, you need the following version of Android
    352 development tools. Use the <a href="{@docRoot}sdk/installing/index.html#AddingComponents">Android SDK
    353 Manager</a> to install these components:</p>
    354 
    355 <ul>
    356   <li>Android SDK Tools, Revision 17 or higher</li>
    357   <li>Android x86-based system image</li>
    358 </ul>
    359 
    360 <p>If your development environment meets all of the requirements for running a VM-accelerated
    361 emulator, you can use the AVD Manager to create an x86-based AVD configuration:</p>
    362 
    363 <ol>
    364   <li>In the Android SDK Manager, make sure you have an x86-based <strong>System Image</strong>
    365     installed for your target Android version. If you do not have an x86 <strong>System
    366     Image</strong> installed, select one in the Android SDK Manager and install it.
    367     <p class="note"><strong>Tip:</strong> System images are listed under each API Level in the SDK
    368     Manager. An x86 system image may not be available for all API levels.</p>
    369   </li>
    370   <li>Start the AVD Manager and create a new AVD with an x86 value for the
    371 <strong>CPU/ABI</strong> field. You may need to select a specific <strong>Target</strong> value, or
    372 select a <strong>Target</strong> value and then select a specific <strong>CPU/ABI</strong>
    373 option.</li>
    374   <li>Name the emulator instance and select any other configuration options.</li>
    375   <li>Click <strong>Create AVD</strong> to save the emulator configuration.</li>
    376 </ol>
    377 
    378 <h4 id="vm-windows">Configuring VM Acceleration on Windows</h4>
    379 
    380 <p>Virtual machine acceleration for Windows requires the installation of the Intel Hardware
    381 Accelerated Execution Manager (Intel HAXM). The software requires an Intel CPU with
    382 Virtualization Technology (VT) support and one of the following operating systems:</p>
    383 
    384 <ul>
    385   <li>Windows 7 (32/64-bit)</li>
    386   <li>Windows Vista (32/64-bit)</li>
    387   <li>Windows XP (32-bit only)</li>
    388 </ul>
    389 
    390 <p>To install the virtualization driver:</p>
    391 
    392 <ol>
    393   <li>Start the Android SDK Manager, select <strong>Extras</strong> and then select <strong>Intel
    394 Hardware Accelerated Execution Manager</strong>.</li>
    395   <li>After the download completes, execute {@code
    396 &lt;sdk&gt;/extras/intel/Hardware_Accelerated_Execution_Manager/IntelHAXM.exe}.</li>
    397   <li>Follow the on-screen instructions to complete installation.</li>
    398   <li>After installation completes, confirm that the virtualization driver is operating correctly by
    399 opening a command prompt window and running the following command:
    400     <pre>sc query intelhaxm</pre>
    401     <p>You should see a status message including the following information:</p>
    402 <pre>
    403 SERVICE_NAME: intelhaxm
    404        ...
    405        STATE              : 4  RUNNING
    406        ...
    407 </pre>
    408   </li>
    409 </ol>
    410 
    411 <p>To run an x86-based emulator with VM acceleration:</p>
    412 <ul>
    413   <li>If you are running the emulator from the command line, just specify an x86-based AVD:
    414 <pre>emulator -avd &lt;avd_name&gt;</pre>
    415     <p class="note"><strong>Note:</strong> You must provide an x86-based AVD configuration
    416 name, otherwise VM acceleration will not be enabled.</p>
    417   </li>
    418   <li>If you are running the emulator from Android Studio, run your Android application with an x86-based
    419 AVD:
    420     <ol>
    421       <li>In Android Studio, click your Android project folder and then select <strong>Run > Edit
    422 Configurations...</strong></li>
    423       <li>In the left panel of the <strong>Run/Debug Configurations</strong> dialog, select your Android
    424 run configuration or create a new configuration.</li>
    425       <li>Under the <strong>Target Device</strong> options, select the x86-based AVD you created
    426 previously.</li>
    427       <li>Run your Android project using this run configuration.</li>
    428     </ol>
    429   </li>
    430 </ul>
    431 
    432 <p>You can adjust the amount of memory available to the Intel HAXM kernel extension by re-running
    433 its installer.</p>
    434 
    435 <p>You can stop using the virtualization driver by uninstalling it. Re-run the installer or use
    436 the Control Panel to remove the software.</p>
    437 
    438 
    439 <h4 id="vm-mac">Configuring VM Acceleration on Mac</h4>
    440 
    441 <p>Virtual machine acceleration on a Mac requires the installation of the Intel Hardware Accelerated
    442 Execution Manager (Intel HAXM) kernel extension to allow the Android emulator to make use of CPU
    443 virtualization extensions. The kernel extension is compatible with Mac OS X Snow Leopard (version
    444 10.6.0) and higher.</p>
    445 
    446 <p>To install the Intel HAXM kernel extension:</p>
    447 
    448 <ol>
    449   <li>Start the Android SDK Manager, select <strong>Extras</strong> and then select <strong>Intel
    450 Hardware Accelerated Execution Manager</strong>.
    451   <li>After the download completes, execute
    452     {@code &lt;sdk&gt;/extras/intel/Hardware_Accelerated_Execution_Manager/IntelHAXM.dmg}.</li>
    453   <li>Double click the <strong>IntelHAXM.mpkg</strong> icon to begin installation.</li>
    454   <li>Follow the on-screen instructions to complete installation.</li>
    455   <li>After installation completes, confirm that the new kernel extension is operating correctly by
    456 opening a terminal window and running the following command:
    457     <pre>kextstat | grep intel</pre>
    458     <p>You should see a status message containing the following extension name, indicating that the
    459       kernel extension is loaded:</p>
    460     <pre>com.intel.kext.intelhaxm</pre>
    461   </li>
    462 </ol>
    463 
    464 <p>To run an x86-based emulator with VM acceleration:</p>
    465 <ul>
    466   <li>If you are running the emulator from the command line, just specify an x86-based AVD:
    467 <pre>emulator -avd &lt;avd_name&gt;</pre>
    468     <p class="note"><strong>Note:</strong> You must provide an x86-based AVD configuration
    469 name, otherwise VM acceleration will not be enabled.</p>
    470   </li>
    471   <li>If you are running the emulator from Andriod Studio, run your Android application with an x86-based
    472 AVD:
    473     <ol>
    474       <li>In Android Studio, click your Android module folder and then select <strong>Run > Edit
    475 Configurations...</strong></li>
    476       <li>In the left panel of the <strong>Run/Debug Configurations</strong> dialog, select your Android
    477 run configuration or create a new configuration.</li>
    478       <li>Under the <strong>Target Device</strong> options,
    479       select the x86-based AVD you created previously.</li>
    480       <li>Run your Android project using this run configuration.</li>
    481     </ol>
    482   </li>
    483 </ul>
    484 
    485 <p>You can adjust the amount of memory available to the Intel HAXM kernel extension by re-running
    486 the installer.</p>
    487 
    488 <p>You can stop using the virtualization kernel driver by uninstalling it. Before removing it, shut
    489 down any running x86 emulators. To unload the virtualization kernel driver, run the following
    490 command in a terminal window:</p>
    491 
    492 <pre>sudo /System/Library/Extensions/intelhaxm.kext/Contents/Resources/uninstall.sh</pre>
    493 
    494 <h4 id="vm-linux">Configuring VM Acceleration on Linux</h4>
    495 
    496 <p>Linux-based systems support virtual machine acceleration through the KVM software package. Follow
    497 <a href="https://www.google.com/?q=kvm+installation">instructions for installing KVM</a> on your
    498 Linux system, and verify that KVM is enabled. In addition to following the installation
    499 instructions, be aware of these configuration requirements:</p>
    500 
    501 <ul>
    502   <li>Running KVM requires specific user permissions, make sure you have sufficient permissions
    503 according to the KVM installation instructions.</li>
    504   <li>If you use another virtualization technology in your Linux platform, unload its kernel driver
    505 before running the x86 emulator. For example, the VirtualBox driver program is {@code vboxdrv}.</li>
    506 </ul>
    507 
    508 <p>To run an x86-based emulator with VM acceleration:</p>
    509 
    510 <ul>
    511   <li>If you are running the emulator from the command line, start the emulator with an x86-based
    512 AVD and include the KVM options:
    513 <pre>emulator -avd &lt;avd_name&gt; -qemu -m 512 -enable-kvm</pre>
    514     <p class="note"><strong>Note:</strong> You must provide an x86-based AVD configuration
    515 name, otherwise VM acceleration will not be enabled.</p>
    516   </li>
    517   <li>If you are running the emulator from Android Studio, run your Android application with an
    518   x86-based AVD and include the KVM options:
    519     <ol>
    520       <li>In Android Studio, click your Android module folder and then select <strong>Run > Edit
    521 Configurations...</strong></li>
    522       <li>In the left panel of the <strong>Run/Debug Configurations</strong> dialog, select your Android
    523 run configuration or create a new configuration.</li>
    524       <li>Under the <strong>Target Device</strong> options, select the x86-based AVD you created
    525 previously.</li>
    526       <li>In the <strong>Emulator</strong> tab, in the
    527       <strong>Additional command line options</strong> field, enter:
    528       <pre>-qemu -m 512 -enable-kvm</pre>
    529       </li>
    530       <li>Run your Android project using this run configuration.</li>
    531     </ol>
    532   </li>
    533 </ul>
    534 
    535 <p class="note"><strong>Important:</strong> When using the {@code -qemu} command line option, make sure
    536 it is the last parameter in your command. All subsequent options are interpreted as qemu-specific
    537 parameters.</p>
    538 
    539 
    540 <h2 id="sdcard">SD Card Emulation</h2>
    541 
    542 <p>You can create a disk image and then load it to the emulator at startup, to
    543 simulate the presence of a user's SD card in the device. To do this, you can specify
    544 an SD card image when you create an AVD, or you can use the mksdcard utility included
    545 in the SDK.</p>
    546 
    547 <p>The following sections describe how to create an SD card disk image, how to copy
    548 files to it, and how to load it in the emulator at startup. </p>
    549 
    550 <p>Note that you can only load a disk image at emulator startup. Similarly, you
    551 can not remove a simulated SD card from a running emulator. However, you can
    552 browse, send files to, and copy/remove files from a simulated SD card either
    553 with adb or the emulator. </p>
    554 
    555 <p>The emulator supports emulated SDHC cards, so you can create an SD card image
    556 of any size up to 128 gigabytes.</p>
    557 
    558 
    559 <h3 id="sdcard-creating">Creating an SD card image</h3>
    560 
    561 <p>There are several ways of creating an SD card image. The easiest way is to use the
    562 <strong>AVD Manager</strong> to create a new SD card by specifying a size when you create an AVD.
    563 You can also use the {@code android} command line tool when creating an AVD. Just add the
    564 <code>-c</code> option to your command: </p>
    565 
    566 <pre>android create avd -n &lt;avd_name&gt; -t &lt;targetID&gt; -c &lt;size&gt;[K|M]</pre>
    567 
    568 <p>The <code>-c</code> option can also be used to to specify a path to an SD card
    569 image for the new AVD. For more information, see <a
    570 href="{@docRoot}tools/devices/managing-avds-cmdline.html">Managing Virtual Devices
    571 from the Command Line</a>.
    572 </p>
    573 
    574 <p>You can also use the mksdcard tool, included in the SDK, to create a FAT32 disk
    575 image that you can load in the emulator at startup. You can access mksdcard in
    576 the tools/ directory of the SDK and create a disk image like this: </p>
    577 
    578 <pre>mksdcard &lt;size&gt; &lt;file&gt;</pre>
    579 
    580 <p>For example:</p>
    581 
    582 <pre>mksdcard 1024M sdcard1.iso</pre>
    583 
    584 <p>For more information, see <a
    585 href="{@docRoot}tools/help/mksdcard.html"><code>mksdcard</code></a>.</p>
    586 
    587 
    588 <h3 id="sdcard-files">Copying files to an SD card image</h3>
    589 
    590 <p>Once you have created the disk image, you can copy files to it prior to
    591 loading it in the emulator. To copy files, you can mount the image as a loop
    592 device and then copy the files to it, or you can use a utility such as {@code mtools} to
    593 copy the files directly to the image. The {@code mtools} package is available for Linux,
    594 Mac, and Windows.</p>
    595 
    596 <p>Alternatively, you can use the {@code adb push} command to move files onto an SD card image
    597 while it is loaded in an emulator. For more information see the <a
    598 href="{@docRoot}tools/help/adb.html#copyfiles">{@code adb push}</a> documentation.</p>
    599 
    600 <h3 id="sdcard-loading">Loading an SD card image</h3>
    601 
    602 <p>By default, the emulator loads the SD card image that is stored with the active
    603 AVD (see the <code>-avd</code> startup option).</p>
    604 
    605 <p>Alternatively, you can start the emulator with the
    606 <code>-sdcard</code> flag and specify the name and path of your image (relative
    607 to the current working directory): </p>
    608 
    609 <pre>emulator -sdcard &lt;filepath&gt;</pre>
    610 
    611 
    612 <h2 id="diskimages">Working with Emulator Disk Images</h2>
    613 
    614 <p>The emulator uses mountable disk images stored on your development machine to
    615 simulate flash (or similar) partitions on an actual device. For example, it uses a
    616 disk image containing an emulator-specific kernel, the Android system, a
    617 ramdisk image, and writeable images for user data and simulated SD card.</p>
    618 
    619 <p>To run properly, the emulator requires access to a specific set of disk image
    620 files. By default, the Emulator always looks for the disk images in the
    621 private storage area of the AVD in use. If no images exist there when
    622 the Emulator is launched, it creates the images in the AVD directory based on
    623 default versions stored in the SDK. </p>
    624 
    625 <p class="note"><strong>Note:</strong> The default storage location for
    626 AVDs is in <code>~/.android/avd</code> on OS X and Linux, <code>C:\Documents and
    627 Settings\&lt;user&gt;\.android\</code> on Windows XP, and
    628 <code>C:\Users\&lt;user&gt;\.android\</code>
    629 on Windows Vista.</p>
    630 
    631 <p>To let you use alternate or custom versions of the image files, the emulator
    632 provides startup options that override the default locations and filenames of
    633 the image files. When you use one of these options, the emulator searches for the image
    634 file under the image name or location that you specify; if it can not locate the
    635 image, it reverts to using the default names and location.</p>
    636 
    637 <p>The emulator uses three types of image files: default image files, runtime
    638 image files, and temporary image files. The sections below describe how to
    639 override the location/name of each type of file. </p>
    640 
    641 <h3 id="defaultimages">Default image files</h3>
    642 
    643 <p>When the emulator launches, but does not find an existing user data image in
    644 the active AVD's storage area, it creates a new one from a default version
    645 included in the SDK. The default user data image is read-only. The image
    646 files are read-only.</p>
    647 
    648 <p>The emulator provides the <code>-system &lt;dir&gt;</code> startup option to
    649 let you override the location where the emulator looks for the default
    650 user data image. </p>
    651 
    652 <p>The emulator also provides a startup option that lets you override the name
    653 of the default user data image, as described in the following table. When you use the
    654 option, the emulator looks in the default directory, or in a custom location
    655 (if you specified <code>-system &lt;dir&gt;</code>). </p>
    656 
    657 
    658 <table>
    659 <tr>
    660   <th width="10%" >Name</th>
    661     <th width="30%" >Description</th>
    662     <th width="40%" >Comments</th>
    663 </tr>
    664 
    665 <!--
    666 <tr>
    667   <td><code>kernel-qemu.img</code></td>
    668   <td>The emulator-specific Linux kernel image</td>
    669   <td>Override using <code>-kernel &lt;file&gt;</code></td>
    670 </tr>
    671 
    672 <tr>
    673   <td><code>ramdisk.img</code></td>
    674   <td>The ramdisk image used to boot the system.</td>
    675   <td>Override using <code>-ramdisk &lt;file&gt;</code></td>
    676 </tr>
    677 
    678 <tr>
    679   <td><code>system.img</code></td>
    680   <td>The <em>initial</em> Android system image.</td>
    681   <td>Override using <code>-image &lt;file&gt;</code></td>
    682 </tr>
    683 -->
    684 <tr>
    685   <td><code>userdata.img</code></td>
    686   <td>The <em>initial</em> user-data disk image</td>
    687   <td>Override using <code>-initdata &lt;file&gt;</code>. Also see
    688 <code>-data &lt;file&gt;</code>, below.</td>
    689 </tr>
    690 
    691 </table>
    692 
    693 <h3 id="runtimeimages">Runtime images: user data and SD card</h3>
    694 
    695 <p>At runtime, the emulator reads and writes data to two disk images: a
    696 user-data image and (optionally) an SD card image. These images emulate the user-data
    697 partition and removable storage media on actual device. </p>
    698 
    699 <p>The emulator provides a default user-data disk image. At startup, the emulator
    700 creates the default image as a copy of the system user-data image (user-data.img),
    701 described above. The emulator stores the new image with the files of the active AVD.</p>
    702 
    703 <!--
    704 <p>The emulator provides a startup option, <code>-datadir &lt;dir&gt;</code>,
    705 that you can use to override the location under which the emulator looks for the runtime
    706 image files. </p>
    707 -->
    708 
    709 <p>The emulator provides startup options to let you override the actual names and storage
    710 locations of the runtime images to load, as described in the following table. When you use one
    711 of these options, the emulator looks for the specified file(s) in the current working directory,
    712 in the AVD directory, or in a custom location (if you specified a path with the filename). </p>
    713 
    714 <table>
    715 <tr>
    716   <th width="10%" >Name</th>
    717     <th width="30%" >Description</th>
    718     <th width="40%" >Comments</th>
    719 </tr>
    720 <tr>
    721   <td><code>userdata-qemu.img</code></td>
    722   <td>An image to which the emulator writes runtime user-data for a unique user.</td>
    723   <td>Override using <code>-data &lt;filepath&gt;</code>, where <code>&lt;filepath&gt;</code> is the
    724 path the image, relative to the current working directory. If you supply a filename only,
    725 the emulator looks for the file in the current working directory. If the file at <code>&lt;filepath&gt;</code> does
    726 not exist, the emulator creates an image from the default <code>userdata.img</code>, stores it under the name you
    727 specified, and persists user data to it at shutdown. </td>
    728 </tr>
    729 
    730 <tr>
    731   <td><code>sdcard.img</code></td>
    732   <td>An image representing an SD card inserted into the emulated device.</td>
    733   <td>Override using <code>-sdcard &lt;filepath&gt;</code>, where <code>&lt;filepath&gt;</code> is the
    734 path the image, relative to the current working directory. If you supply a filename only,
    735 the emulator looks for the file in the current working directory. </td>
    736 </tr>
    737 
    738 </table>
    739 
    740 <h4>User-Data Image</h4>
    741 
    742 <p>Each emulator instance uses a writeable user-data image to store user- and
    743 session-specific data. For example, it uses the image to store a unique user's
    744 installed application data, settings, databases, and files. </p>
    745 
    746 <p>At startup, the emulator attempts to load a user-data image stored during
    747 a previous session. It looks for the file in the current working directory,
    748 in the AVD directory described in a previous section and at the custom location/name
    749 that you specified at startup. </p>
    750 
    751 <ul>
    752 <li>If it finds a user-data image, it mounts the image and makes it available
    753 to the system for reading and writing of user data. </li>
    754 <li>If it does not find one, it creates an image by copying the system user-data
    755 image (userdata.img), described above. At device power-off, the system persists
    756 the user data to the image, so that it will be available in the next session.
    757 Note that the emulator stores the new disk image at the location/name that you
    758 specify in <code>-data</code> startup option.</li>
    759 </ul>
    760 
    761 <p class="note"><strong>Note:</strong> Because of the AVD configurations used in the emulator,
    762 each emulator instance gets its own dedicated storage. There is no longer a need
    763 to use the <code>-d</code> option to specify an instance-specific storage area.</p>
    764 
    765 <h4>SD Card</h4>
    766 
    767 <P>Optionally, you can create a writeable disk image that the emulator can use
    768 to simulate removeable storage in an actual device. For information about how to create an
    769 emulated SD card and load it in the emulator, see <a href="#sdcard">SD Card Emulation</a></p>
    770 
    771 <p>You can also use the android tool to automatically create an SD Card image
    772 for you, when creating an AVD. For more information, see <a
    773 href="{@docRoot}tools/devices/managing-avds.html">Managing Virtual Devices with AVD
    774 Manager</a>.
    775 
    776 
    777 <h3 id="temporaryimages">Temporary Images</h3>
    778 
    779 <p>The emulator creates two writeable images at startup that it deletes at
    780 device power-off. The images are: </p>
    781 
    782 <ul>
    783   <li>A writable copy of the Android system image</li>
    784   <li>The <code>/cache</code> partition image</li>
    785 </ul>
    786 
    787 <p>The emulator does not permit renaming the temporary system image or
    788 persisting it at device power-off. </p>
    789 
    790 <p>The <code>/cache</code> partition image is initially empty, and is used by
    791 the browser to cache downloaded web pages and images. The emulator provides an
    792 <code>-cache &lt;file&gt;</code>, which specifies the name of the file in which
    793 to persist the <code>/cache</code> image at device power-off. If <code>&lt;file&gt;
    794 </code> does not exist, the emulator creates it as an empty file. </p>
    795 
    796 <p>You can also disable the use of the cache partition by specifying the
    797 <code>-nocache</code> option at startup. </p>
    798 
    799 
    800 <h2 id="emulatornetworking">Emulator Networking</h2>
    801 
    802 <p>The emulator provides versatile networking capabilities that you can use to
    803 set up complex modeling and testing environments for your application. The
    804 sections below introduce the emulator's network architecture and capabilities.
    805 </p>
    806 
    807 <h3 id="networkaddresses">Network Address Space</h3>
    808 
    809 <p>Each instance of the emulator runs behind a virtual router/firewall service
    810 that isolates it from your development machine's network interfaces and settings
    811 and from the internet. An emulated device can not see your development machine
    812 or other emulator instances on the network. Instead, it sees only that it is
    813 connected through Ethernet to a router/firewall.</p>
    814 
    815 <p>The virtual router for each instance manages the 10.0.2/24 network address
    816 space &mdash; all addresses managed by the router are in the form of
    817 10.0.2.&lt;xx&gt;, where &lt;xx&gt; is a number. Addresses within this space are
    818 pre-allocated by the emulator/router as follows:</p>
    819 
    820 <table>
    821   <tr>
    822     <th>Network Address</th>
    823     <th>Description</th>
    824   </tr>
    825   <tr>
    826     <td>10.0.2.1</td>
    827     <td>Router/gateway address </td>
    828   </tr>
    829   <tr>
    830     <td>10.0.2.2</td>
    831     <td>Special alias to your host loopback interface (i.e., 127.0.0.1 on your
    832 development machine)</td>
    833   </tr>
    834   <tr>
    835     <td>10.0.2.3</td>
    836     <td>First DNS server</td>
    837   </tr>
    838   <tr>
    839     <td>10.0.2.4 / 10.0.2.5 / 10.0.2.6</td>
    840     <td>Optional second, third and fourth DNS server (if any) </td>
    841   </tr>
    842   <tr>
    843     <td>10.0.2.15</td>
    844     <td>The emulated device's own network/ethernet interface</td>
    845   </tr>
    846   <tr>
    847     <td>127.0.0.1</td>
    848     <td>The emulated device's own loopback interface </td>
    849   </tr>
    850 </table>
    851 
    852 <p>Note that the same address assignments are used by all running emulator
    853 instances. That means that if you have two instances running concurrently on
    854 your machine, each will have its own router and, behind that, each will have an
    855 IP address of 10.0.2.15. The instances are isolated by a router and can
    856 <em>not</em> see each other on the same network. For information about how to
    857 let emulator instances communicate over TCP/UDP, see <a
    858 href="#connecting">Connecting Emulator Instances</a>.</p>
    859 
    860 <p>Also note that the address 127.0.0.1 on your development machine corresponds
    861 to the emulator's own loopback interface. If you want to access services running
    862 on your development machine's loopback interface (a.k.a. 127.0.0.1 on your
    863 machine), you should use the special address 10.0.2.2 instead.</p>
    864 
    865 <p>Finally, note that each emulated device's pre-allocated addresses are
    866 specific to the Android emulator and will probably be very different on real
    867 devices (which are also very likely to be NAT-ed, i.e., behind a
    868 router/firewall)</p>
    869 
    870 
    871 <h3 id="networkinglimitations">Local Networking Limitations</h3>
    872 
    873 <p>Android applications running in an emulator can connect to the network available on your
    874 workstation. However, they connect through the emulator, not directly to hardware, and the emulator
    875 acts like a normal application on your workstation. This means that the emulator, and thus your
    876 Android applications, are subject to some limitations:</p>
    877 
    878 <ul>
    879   <li>Communication with the emulated device may be blocked by a firewall
    880 program running on your machine.</li>
    881   <li>Communication with the emulated device may be blocked by another
    882 (physical) firewall/router to which your machine is connected.</li>
    883 </ul>
    884 
    885 <p>The emulator's virtual router should be able to handle all outbound TCP and
    886 UDP connections/messages on behalf of the emulated device, provided your
    887 development machine's network environment allows it to do so. There are no
    888 built-in limitations on port numbers or ranges except the one imposed by your
    889 host operating system and network.</p>
    890 
    891 <p>Depending on the environment, the emulator may not be able to support other
    892 protocols (such as ICMP, used for "ping") might not be supported. Currently, the
    893 emulator does not support IGMP or multicast. </p>
    894 
    895 <h3 id="redirection">Using Network Redirection</h3>
    896 
    897 <p>To communicate with an emulator instance behind its virtual router, you need
    898 to set up network redirection on the virtual router. Clients can then connect
    899 to a specified guest port on the router, while the router directs traffic
    900 to/from that port to the emulated device's host port. </p>
    901 
    902 <p>To set up the network redirection, you create a mapping of host and guest
    903 ports/addresses on the emulator instance. There are two ways to set up
    904 network redirection: using emulator console commands and using the ADB tool, as
    905 described below. </p>
    906 
    907 
    908 <h4 id="consoleredir">Setting up Redirection through the Emulator Console</h4>
    909 
    910 <p>Each emulator instance provides a control console the you can connect to, to
    911 issue commands that are specific to that instance. You can use the
    912 <code>redir</code> console command to set up redirection as needed for an
    913 emulator instance. </p>
    914 
    915 <p>First, determine the console port number for the target emulator instance.
    916 For example, the console port number for the first emulator instance launched is
    917 5554. Next, connect to the console of the target emulator instance, specifying
    918 its console port number, as follows: </p>
    919 
    920 <pre><code>telnet localhost 5554</code></pre>
    921 
    922 <p>Once connected, use the <code>redir</code> command to work with redirection.
    923 To add a redirection, use:</p>
    924 
    925 <pre><code>add&nbsp;&lt;protocol&gt;:&lt;host-port&gt;:&lt;guest-port&gt;</code>
    926 </pre>
    927 
    928 <p>where <code>&lt;protocol&gt;</code> is either <code>tcp</code> or <code>udp</code>,
    929 and <code>&lt;host-port&gt;</code> and <code>&lt;guest-port&gt;</code> sets the
    930 mapping between your own machine and the emulated system, respectively. </p>
    931 
    932 <p>For example, the following command sets up a redirection that handles all
    933 incoming TCP connections to your host (development) machine on 127.0.0.1:5000
    934 and will pass them through to the emulated system's 10.0.2.15:6000.:</p>
    935 
    936 <pre>redir add tcp:5000:6000</pre>
    937 
    938 <p>To delete a redirection, you can use the <code>redir del</code> command. To
    939 list all redirection for a specific instance, you can use <code>redir
    940 list</code>. For more information about these and other console commands, see
    941 <a href="#console">Using the Emulator Console</a>. </p>
    942 
    943 <p>Note that port numbers are restricted by your local environment. this typically
    944 means that you cannot use host port numbers under 1024 without special
    945 administrator privileges.  Also, you won't be able to set up a redirection for a
    946 host port that is already in use by another process on your machine. In that
    947 case, <code>redir</code> generates an error message to that effect. </p>
    948 
    949 <h4 id="adbredir">Setting Up Redirection through ADB</h4>
    950 
    951 <p>The Android Debug Bridge (ADB) tool provides port forwarding, an alternate
    952 way for you to set up network redirection. For more information, see <a
    953 href="{@docRoot}tools/help/adb.html#forwardports">Forwarding Ports</a> in the ADB
    954 documentation.</p>
    955 
    956 <p>Note that ADB does not currently offer any way to remove a redirection,
    957 except by killing the ADB server.</p>
    958 
    959 
    960 <h3 id="dns">Configuring the Emulator's DNS Settings</h3>
    961 
    962 <p>At startup, the emulator reads the list of DNS servers that your system is
    963 currently using. It then stores the IP addresses of up to four servers on this
    964 list and sets up aliases to them on the emulated addresses 10.0.2.3, 10.0.2.4,
    965 10.0.2.5 and 10.0.2.6 as needed.  </p>
    966 
    967 <p>On Linux and OS X, the emulator obtains the DNS server addresses by parsing
    968 the file <code>/etc/resolv.conf</code>. On Windows, the emulator obtains the
    969 addresses by calling the <code>GetNetworkParams()</code> API. Note that this
    970 usually means that the emulator ignores the content of your "hosts" file
    971 (<code>/etc/hosts</code> on Linux/OS X, <code>%WINDOWS%/system32/HOSTS</code>
    972  on Windows).</P>
    973 
    974 <p>When starting the emulator at the command line, you can also use the
    975 <code>-dns-server &lt;serverList&gt;</code> option to manually specify the
    976 addresses of DNS servers to use, where &lt;serverList&gt; is a comma-separated
    977 list of server names or IP addresses. You might find this option useful if you
    978 encounter DNS resolution problems in the emulated network (for example, an
    979 "Unknown Host error" message that appears when using the web browser).</p>
    980 
    981 
    982 <h3 id="proxy">Using the Emulator with a Proxy</h3>
    983 
    984 <p>If your emulator must access the Internet through a proxy server, you can use
    985 the <code>-http-proxy &lt;proxy&gt;</code> option when starting the emulator, to
    986 set up the appropriate redirection. In this case, you specify proxy information
    987 in <code>&lt;proxy&gt;</code> in one of these formats:</p>
    988 
    989 <pre>http://<machineName>:<port>;</pre>
    990 
    991 <p>or</p>
    992 
    993 <pre>http://<username>:<password>@<machineName>:<port>;</pre>
    994 
    995 <p>The <code>-http-proxy</code> option forces the emulator to use the specified
    996 HTTP/HTTPS proxy for all outgoing TCP connections. Redirection for UDP is not
    997 currently supported.</p>
    998 
    999 <p>Alternatively, you can define the environment variable
   1000 <code>http_proxy</code> to the value you want to use for
   1001 <code>&lt;proxy&gt;</code>. In this case, you do not need to specify a value for
   1002 <code>&lt;proxy&gt;</code> in the <code>-http-proxy</code> command &mdash; the
   1003 emulator checks the value of the <code>http_proxy</code> environment variable at
   1004 startup and uses its value automatically, if defined. </p>
   1005 
   1006 <p>You can use the <code>-verbose-proxy</code> option to diagnose proxy
   1007 connection problems.</p>
   1008 
   1009 
   1010 <h3 id="connecting">Interconnecting Emulator Instances</h3>
   1011 
   1012 <p>To allow one emulator instance to communicate with another, you must set up
   1013 the necessary network redirection as illustrated below. </p>
   1014 
   1015 <p>Assume that your environment is</p>
   1016 
   1017 <ul>
   1018   <li>A is you development machine</li>
   1019   <li>B is your first emulator instance, running on A</li>
   1020   <li>C is your second emulator instance, also running on A</li>
   1021 </ul>
   1022 
   1023 <p>and you want to run a server on B, to which C will connect, here is how you
   1024 could set it up: </p>
   1025 
   1026 <ol>
   1027   <li>Set up the server on B, listening to
   1028 <code>10.0.2.15:&lt;serverPort&gt;</code></li>
   1029   <li>On B's console, set up a redirection from
   1030 <code>A:localhost:&lt;localPort&gt;</code> to <code>
   1031 B:10.0.2.15:&lt;serverPort&gt;</code></li>
   1032   <li>On C, have the client connect to <code>10.0.2.2:&lt;localPort&gt;</code></li>
   1033 </ol>
   1034 
   1035 <p>For example, if you wanted to run an HTTP server, you can select
   1036 <code>&lt;serverPort&gt;</code> as 80 and <code>&lt;localPort&gt;</code> as
   1037 8080:</p>
   1038 
   1039 <ul>
   1040   <li>B listens on 10.0.2.15:80</li>
   1041   <li>On B's console, issue <code>redir add tcp:8080:80</code></li>
   1042   <li>C connects to 10.0.2.2:8080</li>
   1043 </ul>
   1044 
   1045 <h3 id="calling">Sending a Voice Call or SMS to Another Emulator Instance</h3>
   1046 
   1047 <p>The emulator automatically forwards simulated voice calls and SMS messages from one instance to
   1048 another. To send a voice call or SMS, use the dialer application or SMS application, respectively,
   1049 from one of the emulators.</p>
   1050 
   1051 <p>To initiate a simulated voice call to another emulator instance:</p>
   1052 <ol>
   1053 <li>Launch the dialer application on the originating emulator instance.</li>
   1054 <li>As the number to dial, enter the console port number of the instance you'd like to call. You can determine
   1055   the console port number of the target instance by checking its window title, where the
   1056   console port number is reported as "Android Emulator (&lt;port&gt;). </li>
   1057 <li>Press "Dial". A new inbound call appears in the target emulator instance. </li>
   1058 </ol>
   1059 
   1060 <p>To send an SMS message to another emulator instance, launch the SMS application (if available). Specify the console port number of the target emulator instance as as the SMS address, enter the message text, and send the message. The message is delivered to the target emulator instance. </p>
   1061 
   1062 <p>You can also connect to an emulator instance's console to simulate an incoming voice call or SMS. For more information, see <a href="#telephony">Telephony Emulation</a> and <a href="#sms">SMS Emulation</a>.
   1063 
   1064 
   1065 <h2 id="console">Using the Emulator Console</h2>
   1066 
   1067 <p>Each running emulator instance provides a console that lets you query and control the emulated
   1068 device environment. For example, you can use the console to manage port redirection, network
   1069 characteristics, and telephony events while your application is running on the emulator. To
   1070 access the console and enter commands, use telnet to connect to the console's port number.</p>
   1071 
   1072 <p>To connect to the console of any running emulator instance at any time, use this command: </p>
   1073 
   1074 <pre>telnet localhost &lt;console-port&gt;</pre>
   1075 
   1076 <p>An emulator instance occupies a pair of adjacent ports: a console port and an  {@code adb} port.
   1077 The port numbers differ by 1, with the  {@code adb} port having the higher port number. The console
   1078 of the first emulator instance running on a given machine uses console port 5554 and  {@code adb}
   1079 port 5555. Subsequent instances use port numbers increasing by two &mdash; for example, 5556/5557,
   1080 5558/5559, and so on. Up to 16 concurrent emulator instances can run a console facility. </p>
   1081 
   1082 <p>To connect to the emulator console, you must specify a valid console port. If multiple emulator instances are running, you need to determine the console port of the emulator instance you want to connect to. You can find the instance's console port listed in the title of the instance window. For example, here's the window title for an instance whose console port is 5554:</p>
   1083 
   1084 <p><code>Android Emulator (5554)</code></p>
   1085 
   1086 <p>Alternatively, you can use the <code>adb devices</code> command, which prints a list of running emulator instances and their console port numbers. For more information, see <a href="{@docRoot}tools/help/adb.html#devicestatus">Querying for Emulator/Device Instances</a> in the adb documentation.</p>
   1087 
   1088 <p class="note">Note: The emulator listens for connections on ports 5554-5587 and accepts connections only from localhost.</p>
   1089 
   1090 <p>Once you are connected to the console, you can then enter <code>help [command]</code> to see a list of console commands and learn about specific commands. </p>
   1091 
   1092 <p>To exit the console session, use <code>quit</code> or <code>exit</code>.</p>
   1093 
   1094 <p>The following sections below describe the major functional areas of the console.</p>
   1095 
   1096 
   1097 <h3 id="portredirection">Port Redirection</h3>
   1098 
   1099 <p>You can use the console to add and remove port redirection while the emulator is running. After
   1100 you connect to the console, manage port redirection by entering the following command:</p>
   1101 
   1102 <pre>redir &lt;list|add|del&gt; </pre>
   1103 
   1104 <p>The <code>redir</code> command supports the subcommands listed in the table below. </p>
   1105 
   1106 <table>
   1107 <tr>
   1108   <th width="25%" >Subcommand
   1109   <th width="30%" >Description</th>
   1110   <th width="35%">Comments</th>
   1111 </tr>
   1112 
   1113   <tr>
   1114     <td><code>list</code></td>
   1115     <td>List the current port redirection.</td>
   1116   <td>&nbsp;</td>
   1117   </tr>
   1118 
   1119 
   1120 <tr>
   1121  <td><code>add&nbsp;&lt;protocol&gt;:&lt;host-port&gt;:&lt;guest-port&gt;</code></td>
   1122   <td>Add a new port redirection.</td>
   1123 <td><ul><li>&lt;protocol&gt; must be either &quot;tcp&quot; or &quot;udp&quot;</li>
   1124 <li>&lt;host-port&gt; is the port number to open on the host</li>
   1125 <li>&lt;guest-port&gt; is the port number to route data to on the emulator/device</li>
   1126 </ul></td>
   1127 </tr>
   1128 <tr>
   1129   <td><code>del &lt;protocol&gt;:&lt;host-port&gt;</code></td>
   1130   <td>Delete a port redirection.</td>
   1131 <td>The meanings of &lt;protocol&gt; and &lt;host-port&gt; are listed in the previous row.</td>
   1132 </tr>
   1133 </table>
   1134 
   1135 
   1136 <h3 id="geo">Geo Location Provider Emulation</h3>
   1137 
   1138 <p>You can use the console to set the geographic location reported to the applications running
   1139 inside an emulator. Use the <code>geo</code> command to send a simple GPS fix to the
   1140 emulator, with or without NMEA 1083 formatting:</p>
   1141 
   1142 <pre>geo &lt;fix|nmea&gt;</pre>
   1143 
   1144 <p>The <code>geo</code> command supports the subcommands listed in the table below.</p>
   1145 
   1146 <table>
   1147 <tr>
   1148   <th width="25%">Subcommand</th>
   1149   <th width="30%">Description</th>
   1150   <th width="35%">Comments</th>
   1151 </tr>
   1152 
   1153   <tr>
   1154     <td><code>fix &lt;longitude&gt; &lt;latitude&gt; [&lt;altitude&gt;]</code></td>
   1155     <td>Send a simple GPS fix to the emulator instance.</td>
   1156   <td>Specify longitude and latitude in decimal degrees. Specify altitude in meters.</td>
   1157   </tr>
   1158 <tr>
   1159   <td><code>nmea &lt;sentence&gt;</code></td>
   1160   <td>Send an NMEA 0183 sentence to the emulated device, as if it were sent from an emulated GPS modem.</td>
   1161 <td><code>&lt;sentence&gt;</code> must begin with '$GP'. Only '$GPGGA' and '$GPRCM' sentences are currently supported.</td>
   1162 </tr>
   1163 </table>
   1164 
   1165 <p>You can issue the <code>geo</code> command as soon as an emulator instance is running. The
   1166 emulator sets the location you enter by creating a mock location provider. This provider responds to
   1167 location listeners set by applications, and also supplies the location to the {@link
   1168 android.location.LocationManager}. Any application can query the location manager to obtain the
   1169 current GPS fix for the emulated device by calling:
   1170 
   1171 <pre>LocationManager.getLastKnownLocation("gps")</pre>
   1172 
   1173 <p>For more information about the Location Manager, see {@link android.location.LocationManager}.
   1174 </p>
   1175 
   1176 <h3 id="events">Hardware Events Emulation</h3>
   1177 
   1178 <p>The {@code event} console commands sends hardware events to the emulator. The syntax for this
   1179 command is as follows:</p>
   1180 
   1181 <pre>event &lt;send|types|codes|text&gt;</pre>
   1182 
   1183 <p>The <code>event</code> command supports the subcommands listed in the table below. </p>
   1184 
   1185 <table>
   1186 <tr>
   1187   <th width="25%" >Subcommand
   1188   <th width="30%" >Description</th>
   1189   <th width="35%">Comments</th>
   1190 </tr>
   1191 
   1192   <tr>
   1193     <td><code>send &lt;type&gt;:&lt;code&gt;:&lt;value&gt; [...]</code></td>
   1194     <td>Send one or more events to the Android kernel. </td>
   1195   <td>You can use text names or integers for <code>&lt;type&gt;</code> and <code>&lt;value&gt;</code>.</td>
   1196   </tr>
   1197 <tr>
   1198   <td><code>types</code></td>
   1199   <td>List all <code>&lt;type&gt;</code> string aliases supported by the <code>event</code> subcommands.</td>
   1200 <td>&nbsp;</td>
   1201 </tr>
   1202 <tr>
   1203   <td><code>codes &lt;type&gt;</code></td>
   1204   <td>List all <code>&lt;codes&gt;</code> string aliases supported by the <code>event</code>
   1205    subcommands for the specified <code>&lt;type&gt;</code>.</td>
   1206 <td>&nbsp;</td>
   1207 </tr>
   1208 <tr>
   1209   <td><code>event text &lt;message&gt;</code></td>
   1210   <td>Simulate keypresses to send the specified string of characters as a message,</td>
   1211 <td>The message must be a UTF-8 string. Unicode posts will be reverse-mapped according to the current device keyboard. Unsupported characters will be discarded silently.</td>
   1212 </tr>
   1213 </table>
   1214 
   1215 
   1216 <h3 id="power">Device Power Characteristics</h3>
   1217 
   1218 <p>The {@code power} command controls the power state reported by the emulator to applications. The
   1219 syntax for this command is as follows: </p>
   1220 
   1221 <pre>power &lt;display|ac|status|present|health|capacity&gt;</pre>
   1222 
   1223 <p>The <code>event</code> command supports the subcommands listed in the table below. </p>
   1224 
   1225 <table>
   1226 <tr>
   1227   <th width="25%" >Subcommand </th>
   1228   <th width="30%" >Description</th>
   1229   <th width="35%">Comments</th>
   1230 </tr>
   1231 
   1232   <tr>
   1233     <td><code>display</code></td>
   1234     <td>Display battery and charger state.</td>
   1235   <td>&nbsp;</td>
   1236   </tr>
   1237 <tr>
   1238   <td><code>ac &lt;on|off&gt;</code></td>
   1239   <td>Set AC charging state to on or off. </td>
   1240 <td>&nbsp;</td>
   1241 </tr>
   1242 <tr>
   1243   <td><code>status &lt;unknown|charging|discharging|not-charging|full&gt;</code></td>
   1244   <td>Change battery status as specified.</td>
   1245 <td>&nbsp;</td>
   1246 </tr>
   1247 
   1248 <tr>
   1249   <td><code>present &lt;true|false&gt;</code></td>
   1250   <td>Set battery presence state.</td>
   1251 <td>&nbsp;</td>
   1252 </tr>
   1253 <tr>
   1254   <td><code>health &lt;unknown|good|overheat|dead|overvoltage|failure&gt;</code></td>
   1255   <td>Set battery health state.</td>
   1256 <td>&nbsp;</td>
   1257 </tr>
   1258 <tr>
   1259   <td><code>capacity &lt;percent&gt;</code></td>
   1260   <td>Set remaining battery capacity state (0-100).</td>
   1261 <td>&nbsp;</td>
   1262 </tr>
   1263 </table>
   1264 
   1265 
   1266 <h3 id="netstatus">Network Status</h3>
   1267 
   1268 <p>You can use the console to check the network status and current delay and speed characteristics. To do so, connect to the console and use the <code>netstatus</code> command. Here's an example of the command and its output. </p>
   1269 
   1270 <pre>network status
   1271 </pre>
   1272 
   1273 
   1274 <h3 id="netdelay">Network Delay Emulation</h3>
   1275 
   1276 <p>The emulator lets you simulate various network latency levels, so that you can test your
   1277 application in an environment more typical of the actual conditions in which it will run. You can
   1278 set a latency level or range at emulator startup or you can use the console to change the latency,
   1279 while the application is running in the emulator. </p>
   1280 
   1281 <p>To set latency at emulator startup, use the  <code>-netdelay</code> emulator option with a
   1282 supported <code>&lt;delay&gt;</code> value, as listed in the table below. Here are some
   1283 examples:</p>
   1284 
   1285 <pre>emulator -netdelay gprs
   1286 emulator -netdelay 40 100</pre>
   1287 
   1288 <p>To make changes to  network delay while the emulator is running, connect to the console and use
   1289 the <code>netdelay</code> command with a supported <code>&lt;delay&gt;</code> value from the table
   1290 below.</p>
   1291 
   1292 <pre>network delay gprs</pre>
   1293 
   1294 <p>The format of network &lt;delay&gt; is one of the following (numbers are milliseconds):</p>
   1295 
   1296 <table style="clear:right;width:100%;">
   1297 <tr>
   1298   <th width="30%" >Value</th>
   1299   <th width="35%" >Description</th><th width="35%">Comments</th></tr>
   1300 
   1301   <tr><td><code>gprs</code></td><td>GPRS</td>
   1302   <td>(min 150, max 550)</td>
   1303   </tr>
   1304 
   1305 <tr><td><code>edge</code></td><td>EDGE/EGPRS</td>
   1306 <td>(min 80, max 400)</td>
   1307 </tr>
   1308 <tr><td><code>umts</code></td><td>UMTS/3G</td>
   1309 <td>(min 35, max 200)</td>
   1310 </tr>
   1311 <tr><td><code>none</code></td><td>No latency</td><td>(min 0, max 0)</td></tr>
   1312 <tr><td><code>&lt;num&gt;</code></td>
   1313 <td>Emulate an exact latency  (milliseconds).</td>
   1314 <td>&nbsp;</td></tr>
   1315 <tr><td><code>&lt;min&gt;:&lt;max&gt;</code></td>
   1316 <td>Emulate an specified latency range (min, max milliseconds).</td>
   1317 <td>&nbsp;</td></tr>
   1318 </table>
   1319 
   1320 
   1321 <h3 id="netspeed">Network Speed Emulation</h3>
   1322 
   1323 <p>The emulator also lets you simulate various network transfer rates.
   1324 You can set a transfer rate or range at emulator startup or you can use the console to change the
   1325 rate, while the application is running in the emulator.</p>
   1326 
   1327 <p>To set the network speed at emulator startup, use the  <code>-netspeed</code> emulator option with a supported
   1328 <code>&lt;speed&gt;</code> value, as listed in the table below. Here are some examples:</p>
   1329 
   1330 <pre>emulator -netspeed gsm
   1331 emulator -netspeed 14.4 80</pre>
   1332 
   1333 <p>To make changes to network speed while the emulator is running, connect to the console and use
   1334 the <code>netspeed</code> command with a supported <code>&lt;speed&gt;</code> value from the table
   1335 below.</p>
   1336 
   1337 <pre>network speed 14.4 80</pre>
   1338 
   1339 <p>The format of network <code>&lt;speed&gt;</code> is one of the following (numbers are
   1340 kilobits/sec):</p>
   1341 <table style="clear:right;width:100%;">
   1342 <tbody>
   1343 <tr>
   1344   <th width="30%">Value</th>
   1345   <th width="35%">Description</th><th width="35%">Comments</th></tr>
   1346 
   1347   <tr>
   1348   <td><code>gsm</code></td>
   1349   <td>GSM/CSD</td><td>(Up: 14.4, down: 14.4)</td></tr>
   1350 <tr>
   1351   <td><code>hscsd</code></td>
   1352   <td>HSCSD</td><td>(Up: 14.4, down: 43.2)</td></tr>
   1353 <tr>
   1354   <td><code>gprs</code></td>
   1355   <td>GPRS</td><td>(Up: 40.0, down: 80.0)</td></tr>
   1356 <tr>
   1357   <td><code>edge</code></td>
   1358   <td>EDGE/EGPRS</td>
   1359   <td>(Up: 118.4, down: 236.8)</td>
   1360 </tr>
   1361 <tr>
   1362   <td><code>umts</code></td>
   1363   <td>UMTS/3G</td><td>(Up: 128.0, down: 1920.0)</td></tr>
   1364 <tr>
   1365   <td><code>hsdpa</code></td>
   1366   <td>HSDPA</td><td>(Up: 348.0, down: 14400.0)</td></tr>
   1367 <tr>
   1368   <td><code>full</code></td>
   1369   <td>no limit</td><td>(Up: 0.0, down: 0.0)</td></tr>
   1370 <tr>
   1371   <td><code>&lt;num&gt;</code></td>
   1372   <td>Set an exact rate used for both upload and download.</td><td></td></tr>
   1373 <tr>
   1374   <td><code>&lt;up&gt;:&lt;down&gt;</code></td>
   1375   <td>Set exact rates for upload and download separately.</td><td></td></tr>
   1376 </table>
   1377 
   1378 
   1379 <h3 id="telephony">Telephony Emulation</h3>
   1380 
   1381 <p>The Android emulator includes its own GSM emulated modem that lets you simulate telephony
   1382 functions in the emulator. For example, you can simulate inbound phone calls, establish data
   1383 connections and terminate them. The Android system handles simulated calls exactly as it would
   1384 actual calls. The emulator does not support call audio.</p>
   1385 
   1386 <p>You can use the {@code gsm} command to access the emulator's telephony functions after connecting
   1387 to the console. The syntax for this command is as follows:</p>
   1388 
   1389 <pre>gsm &lt;call|accept|busy|cancel|data|hold|list|voice|status&gt; </pre>
   1390 
   1391 <p>The <code>gsm</code> command supports the subcommands listed in the table below. </p>
   1392 <table>
   1393   <tr>
   1394     <th>Subcommand </th>
   1395     <th width="25%">Description</th>
   1396     <th>Comments</th>
   1397   </tr>
   1398   <tr>
   1399     <td><code>call &lt;phonenumber&gt;</code></td>
   1400     <td>Simulate an inbound phone call from &lt;phonenumber&gt;.</td>
   1401     <td>&nbsp;</td>
   1402   </tr>
   1403   <tr>
   1404     <td><code>accept &lt;phonenumber&gt;</code></td>
   1405     <td>Accept an inbound call from &lt;phonenumber&gt; and change the call's state "active".</td>
   1406     <td>You can change a call's state to "active" only if its current state is "waiting" or "held".</td>
   1407   </tr>
   1408   <tr>
   1409     <td><code>busy &lt;phonenumber&gt;</code></td>
   1410     <td>Close an outbound call to &lt;phonenumber&gt; and change the call's state to "busy".</td>
   1411     <td>You can change a call's state to "busy" only if its current state is "waiting".</td>
   1412   </tr>
   1413   <tr>
   1414     <td><code>cancel &lt;phonenumber&gt;</code></td>
   1415     <td>Terminate an inbound or outbound phone call to/from &lt;phonenumber&gt;.</td>
   1416     <td>&nbsp;</td>
   1417   </tr>
   1418   <tr>
   1419     <td><code>data &lt;state&gt;</code></td>
   1420     <td>Change the state of the GPRS data connection to &lt;state&gt;.</td>
   1421     <td>Supported &lt;state&gt; values are:<br />
   1422     <ul>
   1423           <li><code>unregistered</code> -- No network available</li>
   1424           <li><code>home</code> -- On local network, non-roaming</li>
   1425           <li><code>roaming</code> -- On roaming network</li>
   1426           <li><code>searching</code> -- Searching networks</li>
   1427           <li><code>denied</code> -- Emergency calls only</li>
   1428           <li><code>off</code> -- Same as 'unregistered'</li>
   1429       <li><code>on</code> -- same as 'home'</li>
   1430     </ul>
   1431           </td>
   1432   </tr>
   1433   <tr>
   1434     <td><code>hold</code></td>
   1435     <td>Change the state of a call to "held". </td>
   1436     <td>You can change a call's state to "held" only if its current state is	 "active" or "waiting". </td>
   1437   </tr>
   1438   <tr>
   1439     <td><code>list</code></td>
   1440     <td>List all inbound and outbound calls and their states.</td>
   1441     <td>&nbsp;</td>
   1442   </tr>
   1443   <tr>
   1444     <td><code>voice &lt;state&gt;</code></td>
   1445     <td>Change the state of the GPRS voice connection to &lt;state&gt;.</td>
   1446     <td>Supported &lt;state&gt; values are:<br />
   1447     <ul>
   1448     <li><code>unregistered</code> -- No network available</li>
   1449     <li><code>home</code> -- On local network, non-roaming</li>
   1450     <li><code>roaming</code> -- On roaming network</li>
   1451     <li><code>searching</code> -- Searching networks</li>
   1452     <li><code>denied</code> -- Emergency calls only</li>
   1453     <li><code>off</code> -- Same as 'unregistered'</li>
   1454     <li><code>on</code> -- Same as 'home'</li>
   1455     </ul>
   1456     </td>
   1457   </tr>
   1458 
   1459   <tr>
   1460     <td><code>status</code></td>
   1461     <td>Report the current GSM voice/data state.</td>
   1462     <td>Values are those described for the <code>voice</code> and <code>data</code> commands.</td>
   1463   </tr>
   1464 </table>
   1465 
   1466 
   1467 <h3 id="sms">SMS Emulation</h3>
   1468 
   1469 <p>The Android emulator console lets you generate an SMS message and direct it to an emulator
   1470 instance. Once you connect to an emulator instance, you can generate an emulated incoming SMS using
   1471 the following command:</p>
   1472 
   1473 <pre>sms send &lt;senderPhoneNumber&gt; &lt;textmessage&gt;</pre>
   1474 
   1475 <p>where <code>&lt;senderPhoneNumber&gt;</code> contains an arbitrary numeric string. </p>
   1476 
   1477 <p>The console forwards the SMS message to the Android framework, which passes it through to an application that handles that message type. </p>
   1478 
   1479 
   1480 <h3 id="vm">VM State</h3>
   1481 
   1482 <p>You can use the <code>vm</code> command to control the VM on an emulator instance. The syntax for
   1483 this command is as follows: </p>
   1484 
   1485 <pre>vm &lt;start|stop|status&gt;</pre>
   1486 
   1487 <p>The <code>vm</code> command supports the subcommands listed in the table below. </p>
   1488 
   1489 <table>
   1490 <tr>
   1491   <th width="25%">Subcommand</th>
   1492   <th width="30%">Description</th>
   1493   <th width="35%">Comments</th>
   1494 </tr>
   1495 <tr>
   1496     <td><code>start</code></td>
   1497     <td>Start the VM on the instance. </td>
   1498   <td>&nbsp;</td>
   1499 </tr>
   1500 <tr>
   1501     <td><code>stop</code></td>
   1502     <td>Stop the VM on the instance. </td>
   1503   <td>&nbsp;</td>
   1504 </tr>
   1505 <tr>
   1506     <td><code>start</code></td>
   1507     <td>Display the current status of the VM (running or stopped). </td>
   1508   <td>&nbsp;</td>
   1509 </tr>
   1510 </table>
   1511 
   1512 
   1513 <h3 id="window">Emulator Window</h3>
   1514 
   1515 <p>You can use the <code>window</code> command to manage the emulator window. The syntax for this
   1516 command is as follows: </p>
   1517 
   1518 <pre>window &lt;scale&gt;</pre>
   1519 
   1520 <p>The <code>vm</code> command supports the subcommands listed in the table below. </p>
   1521 
   1522 <table>
   1523 <tr>
   1524   <th width="25%">Subcommand</th>
   1525   <th width="30%">Description</th>
   1526   <th width="35%">Comments</th>
   1527 </tr>
   1528 <tr>
   1529     <td><code>scale &lt;scale&gt;</code></td>
   1530     <td>Scale the emulator window.</td>
   1531   <td>A number between 0.1 and 3 that sets the scaling factor. You can
   1532   also specify scale as a DPI value if you add the suffix "dpi" to the scale value. A value of "auto"
   1533   tells the emulator to select the best window size.</td>
   1534 </tr>
   1535 </table>
   1536 
   1537 
   1538 <h3 id="terminating">Terminating an Emulator Instance</h3>
   1539 
   1540 <p>You can terminate an emulator instance through the console, using the <code>kill</code> command.</p>
   1541 
   1542 
   1543 <h2 id="limitations">Emulator Limitations</h2>
   1544 
   1545 <p>The functional limitations of the emulator include: </p>
   1546 <ul>
   1547   <li>No support for placing or receiving actual phone calls. You can simulate phone calls (placed
   1548     and received) through the emulator console, however. </li>
   1549   <li>No support for USB connections</li>
   1550   <li>No support for device-attached headphones</li>
   1551   <li>No support for determining network connected state</li>
   1552   <li>No support for determining battery charge level and AC charging state</li>
   1553   <li>No support for determining SD card insert/eject</li>
   1554   <li>No support for Bluetooth</li>
   1555 </ul>
   1556 
   1557 
   1558 <h2 id="troubleshooting">Troubleshooting Emulator Problems</h2>
   1559 
   1560 <p>The {@code adb} utility sees the emulator as an actual physical device. For this reason, you
   1561 might have to use the {@code -d} flag with some common {@code adb} commands, such as
   1562 <code>install</code>. The {@code -d} flag lets you specify which of several connected devices to use
   1563 as the target of a command. If you don't specify {@code -d}, the emulator targets the first
   1564 device in its list. For more information about {@code adb}, see <a
   1565 href="{@docRoot}tools/help/adb.html">Android Debug Bridge</a>.</p>
   1566 
   1567 <p>For emulators running on Mac OS X, if you see an error {@code Warning: No DNS servers found}
   1568 when starting the emulator, check to see whether you have an <code>/etc/resolv.conf</code> file. If
   1569 not, please run the following line in a command window:</p>
   1570     <pre>ln -s /private/var/run/resolv.conf /etc/resolv.conf</pre>
   1571 
   1572 <p>See <a href="{@docRoot}resources/faq/index.html">Frequently Asked Questions</a> for more
   1573 troubleshooting information. </p>
   1574