Android Virtual Devices (AVDs) are configurations of emulator options that let you better model an actual device.
Each AVD is made up of:
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.
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 Emulator documentation.
To create and manage AVDs, you use the android tool provided in the Android SDK. For more information about how to work with AVDs from inside your development environment, see Developing in Eclipse with ADT or Developing in Other IDEs, as appropriate for your environment.
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).
To create an AVD, you use the android tool, a command-line utility
available in the
<sdk>/tools/ directory. Managing AVDs is one
of the two main function of the android tool (the other is creating and updating
Android projects). Open a terminal window and change to the
<sdk>/tools/ directory, if needed
To create each AVD, you issue the command
android create avd,
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.
Here's the command-line usage for creating an AVD:
android create avd -n <name> -t <targetID> [-<option> <value>] ...
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.
As shown in the usage above, you must use the
--target) 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 — 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
To specify the system image to use, you refer to its target ID
— an integer — as assigned by the android 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 android tool list the available system images and the
target ID of each, as described in the next section. You should do this
before you run the
android create avd command.
To generate a list of system image targets, use this command:
android list targets
The android tool scans the
<sdk>/add-ons directories looking for valid system images and
then generates the list of targets. Here's an example of the command output:
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
Once you have generated the list of targets available, you can look at the characteristics of each system image — name, API Level, external libraries, and so on — and determine which target is appropriate for the new AVD.
Keep these points in mind when you are selecting a system image target for your AVD:
minSdkVersionattribute of the application's manifest file. For more information about the relationship between system API Level and application
minSdkVersion, see Specifying Minimum System API Version.
uses-libraryelement 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
uses-libraryelement and select a system image target that includes that library.
When you've selected the target you want to use and made a note of its ID,
android create avd command to create the AVD, supplying the
target ID as the
-t 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):
android create avd -n my_android1.5 -t 2
If the target you selected was a standard Android system image ("Type: platform"), the android tool next asks you whether you want to create a custom hardware profile.
Android 1.5 is a basic Android platform. Do you wish to create a custom hardware profile [no]
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 android tool creates the AVD with name and system image mapping you requested, with the options you specified.
If you are creating an AVD whose target is an SDK add-on, the android 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.
For a list of options you can use in the
android create avd
command, see the table in Command-line options for AVDs,
at the bottom of
When are creating a new AVD that uses a standard Android system image ("Type: platform"), the android 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).
|Device ram size||The amount of physical RAM on the device, in megabytes. Default value is "96".||hw.ramSize|
|Touch-screen support||Whether there is a touch screen or not on the device. Default value is "yes".||hw.touchScreen|
|Trackball support||Whether there is a trackball on the device. Default value is "yes".||hw.trackBall|
|Keyboard support||Whether the device has a QWERTY keyboard. Default value is "yes".||hw.keyboard|
|DPad support||Whether the device has DPad keys. Default value is "yes".||hw.dPad|
|GSM modem support||Whether there is a GSM modem in the device. Default value is "yes".||hw.gsmModem|
|Camera support||Whether the device has a camera. Default value is "no".||hw.camera|
|Maximum horizontal camera pixels||Default value is "640".||hw.camera.maxHorizontalPixels|
|Maximum vertical camera pixels||Default value is "480".||hw.camera.maxVerticalPixels|
|GPS support||Whether there is a GPS in the device. Default value is "yes".||hw.gps|
|Battery support||Whether the device can run on a battery. Default value is "yes".||hw.battery|
|Accelerometer||Whether there is an accelerometer in the device. Default value is "yes".||hw.accelerometer|
|Audio recording support||Whether the device can record audio. Default value is "yes".||hw.audioInput|
|Audio playback support||Whether the device can play audio. Default value is "yes".||hw.audioOutput|
|SD Card support||Whether the device supports insertion/removal of virtual SD Cards. Default value is "yes".||hw.sdCard|
|Cache partition support||Whether we use a /cache partition on the device. Default value is "yes".||disk.cachePartition|
|Cache partition size||Default value is "66MB".||disk.cachePartition.size|
When you create an AVD, the android 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 — instead, the AVD configuration file contains a mapping to the system image, which it loads when the AVD is launched.
The android tool also creates a <AVD name>.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.
By default, the android tool creates the AVD directory inside
~/.android/avd/ (on Linux/Mac),
Settings\<user>\.android\ on Windows XP, and
C:\Users\<user>\.android\ on Windows Vista.
If you want to use a custom location for the AVD directory, you
can do so by using the
-p <path> option when
you create the AVD:
android create avd -n my_android1.5 -t 2 -p path/to/my/avd
If the .android directory is hosted on a network drive, we recommend using
-p 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.
The sections below provide more information about how to manage AVDs once you've created them.
If you want to move or rename an AVD, you can do so using this command:
android move avd -n <name> [-<option> <value>] ...
The options for this command are listed in Command-line options for AVDs at the bottom of this page.
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
android list targets command will produce this output:
The following Android Virtual Devices could not be loaded: Name: foo Path: <path>/.android/avd/foo.avd Error: Invalid value in image.sysdir. Run 'android update avd -n foo'
To fix this error, use the
android update avd command to recompute the path to the system images.
You can use the android tool to delete an AVD. Here is the command usage:
android delete avd -n <name>
When you issue the command, the android tool looks for an AVD matching the specified name deletes the AVD's directory and files.
The table below lists the command-line options you can use with the android tool.
||List all known AVDs, with name, path, target, and skin.|
||The name for the AVD.||Required|
||Target ID of the system image to use with the new AVD.||Required. To obtain a list of available targets, use
||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.||Examples:
||Force creation of the AVD||By default, if the name of the AVD being created matches that of an
existing AVD, the android tool will not create the new AVD or overwrite
the existing AVD. If you specify the
||Path to the location at which to create the directory for this AVD's files.|
||The skin to use for this AVD, identified by name or dimensions.||The android tool scans for a matching skin by name or dimension in the
||Delete the specified AVD.||Required|
||The name of the AVD to move.||Required|
||The path to the new location for the AVD.|
||Rename the AVD.|
||Recompute the paths to all system images.|