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 <h1>Android 2.2 Compatibility Definition</h1>
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 <p>Copyright &copy; 2010, Google Inc. All rights reserved.<br/>
 <a href="mailto:compatibility@android.com">compatibility@android.com</a>
 </p>

 <h2> Table of Contents</h2>
 <div style="margin-left: 2em;">
   <a href="#section-1">1. Introduction</a><br/>
   <a href="#section-2">2. Resources</a><br/>
   <a href="#section-3">3. Software</a><br/>
   <div style="margin-left: 2em;">
     <a href="#section-3.1">3.1. Managed API Compatibility</a><br/>
     <a href="#section-3.2">3.2. Soft API Compatibility</a><br/>
     <div style="margin-left: 2em;">
       <a href="#section-3.2.1">3.2.1. Permissions</a><br/>
       <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/>
       <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/>
       <div style="margin-left: 2em;">
         <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/>
         <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/>
         <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/>
         <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/>
       </div>
     </div>
     <a href="#section-3.3">3.3. Native API Compatibility</a><br/>
     <a href="#section-3.4">3.4. Web Compatibility</a><br/>
     <div style="margin-left: 2em;">
       <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/>
       <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/>
     </div>
     <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/>
     <a href="#section-3.6">3.6. API Namespaces</a><br/>
     <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/>
     <a href="#section-3.8">3.8. User Interface Compatibility</a><br/>
     <div style="margin-left: 2em;">
       <a href="#section-3.8.1">3.8.1. Widgets</a><br/>
       <a href="#section-3.8.2">3.8.2. Notifications</a><br/>
       <a href="#section-3.8.3">3.8.3. Search</a><br/>
       <a href="#section-3.8.4">3.8.4. Toasts</a><br/>
       <a href="#section-3.8.5">3.8.5. Live Wallpapers</a><br/>
     </div>
   </div>
   <a href="#section-4">4. Reference Software Compatibility</a><br/>
   <a href="#section-5">5. Application Packaging Compatibility</a><br/>
   <a href="#section-6">6. Multimedia Compatibility</a><br/>
     <div style="margin-left: 2em;">
       <a href="#section-6.1">6.1. Media Codecs</a><br/>
       <a href="#section-6.2">6.2. Audio Recording</a><br/>
       <a href="#section-6.3">6.3. Audio Latency</a><br/>
     </div>
   <a href="#section-7">7. Developer Tool Compatibility</a><br/>
   <a href="#section-8">8. Hardware Compatibility</a><br/>
   <div style="margin-left: 2em;">
     <a href="#section-8.1">8.1. Display</a><br/>
     <div style="margin-left: 2em;">
       <a href="#section-8.1.2">8.1.2. Non-Standard Display Configurations</a><br/>
       <a href="#section-8.1.3">8.1.3. Display Metrics</a><br/>
       <a href="#section-8.1.4">8.1.4. Declared Screen Support</a><br/>
     </div>
     <a href="#section-8.2">8.2. Keyboard</a><br/>
     <a href="#section-8.3">8.3. Non-touch Navigation</a><br/>
     <a href="#section-8.4">8.4. Screen Orientation</a><br/>
     <a href="#section-8.5">8.5. Touchscreen input</a><br/>
     <a href="#section-8.6">8.6. USB</a><br/>
     <a href="#section-8.7">8.7. Navigation keys</a><br/>
     <a href="#section-8.8">8.8. Wireless Data Networking</a><br/>
     <a href="#section-8.9">8.9. Camera</a><br/>
     <a href="#section-8.10">8.10. Accelerometer</a><br/>
     <a href="#section-8.11">8.11. Compass</a><br/>
     <a href="#section-8.12">8.12. GPS</a><br/>
     <a href="#section-8.13">8.13. Telephony</a><br/>
     <a href="#section-8.14">8.14. Memory and Storage</a><br/>
     <a href="#section-8.15">8.15. Application Shared Storage</a><br/>
     <a href="#section-8.16">8.16. Bluetooth</a><br/>
   </div>
   <a href="#section-9">9. Performance Compatibility</a><br/>
   <a href="#section-10">10. Security Model Compatibility</a><br/>
   <div style="margin-left: 2em;">
     <a href="#section-10.1">10.1. Permissions</a><br/>
     <a href="#section-10.2">10.2. UID and Process Isolation</a><br/>
     <a href="#section-10.3">10.3. Filesystem Permissions</a><br/>
     <a href="#section-10.4">10.4. Alternate Execution Environments</a><br/>
   </div>
   <a href="#section-11">11. Compatibility Test Suite</a><br/>
   <a href="#section-12">12. Updatable Software</a><br/>
   <a href="#section-13">13. Contact Us</a><br/>
   <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/>
 </div>

 <div style="page-break-before: always;"></div>

 <a name="section-1"></a><h2>1. Introduction</h2>
 <p>This document enumerates the requirements that must be met in order for
 mobile phones to be compatible with Android 2.2.</p>
 <p>The use of "must", "must not", "required", "shall", "shall not", "should",
 "should not", "recommended", "may" and "optional" is per the IETF standard
 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p>
 <p>As used in this document, a "device implementer" or "implementer" is a
 person or organization developing a hardware/software solution running Android
 2.2. A "device implementation" or "implementation" is the hardware/software
 solution so developed.</p>
 <p>To be considered compatible with Android 2.2, device implementations:</p>
 <ul>
 <li>MUST meet the requirements presented in this Compatibility Definition,
 including any documents incorporated via reference.</li>
 <li>MUST pass the most recent version of the Android Compatibility Test Suite
 (CTS) available at the time of the device implementation's software is
 completed. (The CTS is available as part of the Android Open Source Project [<a
 href="#resources02">Resources, 2</a>].) The CTS tests many, but not all, of the
 components outlined in this document.</li>
 </ul>
 <p>Where this definition or the CTS is silent, ambiguous, or incomplete, it is
 the responsibility of the device implementer to ensure compatibility with
 existing implementations. For this reason, the Android Open Source Project [<a
 href="#resources03">Resources, 3</a>] is both the reference and preferred
 implementation of Android. Device implementers are strongly encouraged to base
 their implementations on the "upstream" source code available from the Android
 Open Source Project. While some components can hypothetically be replaced with
 alternate implementations this practice is strongly discouraged, as passing
 the CTS tests will become substantially more difficult. It is the
 implementer's responsibility to ensure full behavioral compatibility with the
 standard Android implementation, including and beyond the Compatibility Test
 Suite. Finally, note that certain component substitutions and modifications
 are explicitly forbidden by this document.</p>

 <a name="section-2"></a><h2>2. Resources</h2>
 <ol>
 <a name="resources01"></a><li>IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></li>
 <a name="resources02"></a><li>Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></li>
 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li>
 <a name="resources04"></a><li>API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></li>
 <a name="resources05"></a><li>Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></li>
 <a name="resources06"></a><li>android.os.Build reference: <a href="http://developer.android.com/reference/android/os/Build.html">http://developer.android.com/reference/android/os/Build.html</a></li>
 <a name="resources07"></a><li>Android 2.2 allowed version strings: <a href="http://source.android.com/compatibility/2.2/versions.html">http://source.android.com/compatibility/2.2/versions.html</a></li>
 <a name="resources08"></a><li>android.webkit.WebView class: <a href="http://developer.android.com/reference/android/webkit/WebView.html">http://developer.android.com/reference/android/webkit/WebView.html</a></li>
 <a name="resources09"></a><li>HTML5: <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/">http://www.whatwg.org/specs/web-apps/current-work/multipage/</a></li>
 <a name="resources10"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li>
 <a name="resources11"></a><li>AppWidgets: <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">http://developer.android.com/guide/practices/ui_guidelines/widget_design.html</a></li>
 <a name="resources12"></a><li>Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></li>
 <a name="resources13"></a><li>Application Resources: <a href="http://code.google.com/android/reference/available-resources.html">http://code.google.com/android/reference/available-resources.html</a></li>
 <a name="resources14"></a><li>Status Bar icon style guide: <a href="http://developer.android.com/guide/practices/ui_guidelines/icon_design.html#statusbarstructure">http://developer.android.com/guide/practices/ui_guideline /icon_design.html#statusbarstructure</a></li>
 <a name="resources15"></a><li>Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></li>
 <a name="resources16"></a><li>Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></li>
 <a name="resources17"></a><li>Live Wallpapers: <a href="http://developer.android.com/resources/articles/live-wallpapers.html">http://developer.android.com/resources/articles/live-wallpapers.html</a></li>
 <a name="resources18"></a><li>Apps for Android: <a href="http://code.google.com/p/apps-for-android">http://code.google.com/p/apps-for-android</a></li>
 <a name="resources19"></a><li>Reference tool documentation (for adb, aapt, ddms): <a href="http://developer.android.com/guide/developing/tools/index.html">http://developer.android.com/guide/developing/tools/index.html</a></li>
 <a name="resources20"></a><li>Android apk file description: <a href="http://developer.android.com/guide/topics/fundamentals.html">http://developer.android.com/guide/topics/fundamentals.html</a></li>
 <a name="resources21"></a><li>Manifest files: <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">http://developer.android.com/guide/topics/manifest/manifest-intro.html</a></li>
 <a name="resources22"></a><li>Monkey testing tool: <a href="http://developer.android.com/guide/developing/tools/monkey.html">http://developer.android.com/guide/developing/tools/monkey.html</a></li>
 <a name="resources23"></a><li>Android Hardware Features List: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></li>
 <a name="resources24"></a><li>Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></li>
 <a name="resources25"></a><li>android.content.res.Configuration: <a href="http://developer.android.com/reference/android/content/res/Configuration.html">http://developer.android.com/reference/android/content/res/Configuration.html</a></li>
 <a name="resources26"></a><li>android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></li>
 <a name="resources27"></a><li>android.hardware.Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></li>
 <a name="resources28"></a><li>Sensor coordinate space: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></li>
 <a name="resources29"></a><li>Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/security.html">http://developer.android.com/guide/topics/security/security.html</a></li>
 <a name="resources30"></a><li>Bluetooth API: <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">http://developer.android.com/reference/android/bluetooth/package-summary.html</a></li>
 </ol>
 <p>Many of these resources are derived directly or indirectly from the Android
 2.2 SDK, and will be functionally identical to the information in that SDK's
 documentation. In any cases where this Compatibility Definition or the
 Compatibility Test Suite disagrees with the SDK documentation, the SDK
 documentation is considered authoritative. Any technical details provided in
 the references included above are considered by inclusion to be part of this
 Compatibility Definition.</p>

 <a name="section-3"></a><h2>3. Software</h2>
 <p>The Android platform includes a set of managed APIs, a set of native APIs,
 and a body of so-called "soft" APIs such as the Intent system and
 web-application APIs. This section details the hard and soft APIs that are
 integral to compatibility, as well as certain other relevant technical and
 user interface behaviors. Device implementations MUST comply with all the
 requirements in this section.</p>

 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3>
 <p>The managed (Dalvik-based) execution environment is the primary vehicle for
 Android applications. The Android application programming interface (API) is
 the set of Android platform interfaces exposed to applications running in the
 managed VM environment. Device implementations MUST provide complete
 implementations, including all documented behaviors, of any documented API
 exposed by the Android 2.2 SDK [<a href="#resources04">Resources, 4</a>].</p>
 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces
 or signatures, deviate from the documented behavior, or include no-ops, except
 where specifically allowed by this Compatibility Definition.</p>

 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3>
 <p>In addition to the managed APIs from Section 3.1, Android also includes a
 significant runtime-only "soft" API, in the form of such things such as
 Intents, permissions, and similar aspects of Android applications that cannot
 be enforced at application compile time. This section details the "soft" APIs
 and system behaviors required for compatibility with Android 2.2. Device
 implementations MUST meet all the requirements presented in this section.</p>
 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4>
 <p>Device implementers MUST support and enforce all permission constants as
 documented by the Permission reference page [<a
 href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional
 requirements related to the Android security model.</p>
 <a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4>
 <p>The Android APIs include a number of constants on the <code>android.os.Build</code>
 class [<a href="#resources06">Resources, 6</a>] that are intended to describe
 the current device. To provide consistent, meaningful values across device
 implementations, the table below includes additional restrictions on the
 formats of these values to which device implementations MUST conform.</p>
 <table>
 <tbody>
 <tr>
 <td><b>Parameter</b></td>
 <td><b>Comments</b></td>
 </tr>
 <tr>
 <td>android.os.Build.VERSION.RELEASE</td>
 <td>The version of the currently-executing Android system, in human-readable
 format. This field MUST have one of the string values defined in [<a
 href="#resources07">Resources, 7</a>].</td>
 </tr>
 <tr>
 <td>android.os.Build.VERSION.SDK</td>
 <td>The version of the currently-executing Android system, in a format
 accessible to third-party application code. For Android 2.2, this field MUST have
 the integer value 8.</td>
 </tr>
 <tr>
 <td>android.os.Build.VERSION.INCREMENTAL</td>
 <td>A value chosen by the device implementer designating the specific build of
 the currently-executing Android system, in human-readable format. This value
 MUST NOT be re-used for different builds made available to end users. A typical use
 of this field is to indicate which build number or source-control change
 identifier was used to generate the build. There are no requirements on the
 specific format of this field, except that it MUST NOT be null or the empty
 string ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.BOARD</td>
 <td>A value chosen by the device implementer identifying the specific internal
 hardware used by the device, in human-readable format. A possible use of this
 field is to indicate the specific revision of the board powering the device.
 There are no requirements on the specific format of this field, except that it
 MUST NOT be null or the empty string ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.BRAND</td>
 <td>A value chosen by the device implementer identifying the name of the
 company, organization, individual, etc. who produced the device, in
 human-readable format. A possible use of this field is to indicate the OEM
 and/or carrier who sold the device. There are no requirements on the specific
 format of this field, except that it MUST NOT be null or the empty string
 ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.DEVICE</td>
 <td>A value chosen by the device implementer identifying the specific
 configuration or revision of the body (sometimes called "industrial design")
 of the device. There are no requirements on the specific format of this field,
 except that it MUST NOT be null or the empty string ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.FINGERPRINT</td>
 <td>A string that uniquely identifies this build. It SHOULD be reasonably
 human-readable. It MUST follow this template:
 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE)/$(BOARD):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/>
 For example:
 <br/><code>acme/mydevice/generic/generic:2.2/ERC77/3359:userdebug/test-keys</code><br/>
 The fingerprint MUST NOT include whitespace characters. If other fields included in the
 template above have whitespace characters, they MUST be replaced in the build
 fingerprint with another character, such as the underscore ("_") character.</td>
 </tr>
 <tr>
 <td>android.os.Build.HOST</td>
 <td>A string that uniquely identifies the host the build was built on, in
 human readable format. There are no requirements on the specific format of
 this field, except that it MUST NOT be null or the empty string ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.ID</td>
 <td>An identifier chosen by the device implementer to refer to a specific
 release, in human readable format. This field can be the same as
 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently
 meaningful for end users to distinguish between software builds. There are no
 requirements on the specific format of this field, except that it MUST NOT be
 null or the empty string ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.MODEL</td>
 <td>A value chosen by the device implementer containing the name of the device
 as known to the end user. This SHOULD be the same name under which the device
 is marketed and sold to end users. There are no requirements on the specific
 format of this field, except that it MUST NOT be null or the empty string
 ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.PRODUCT</td>
 <td>A value chosen by the device implementer containing the development name
 or code name of the device. MUST be human-readable, but is not necessarily
 intended for view by end users. There are no requirements on the specific
 format of this field, except that it MUST NOT be null or the empty string
 ("").</td>
 </tr>
 <tr>
 <td>android.os.Build.TAGS</td>
 <td>A comma-separated list of tags chosen by the device implementer that
 further distinguish the build. For example, "unsigned,debug". This field MUST
 NOT be null or the empty string (""), but a single tag (such as "release") is
 fine.</td>
 </tr>
 <tr>
 <td>android.os.Build.TIME</td>
 <td>A value representing the timestamp of when the build occurred.</td>
 </tr>
 <tr>
 <td>android.os.Build.TYPE</td>
 <td>A value chosen by the device implementer specifying the runtime
 configuration of the build. This field SHOULD have one of the values
 corresponding to the three typical Android runtime configurations: "user",
 "userdebug", or "eng".</td>
 </tr>
 <tr>
 <td>android.os.Build.USER</td>
 <td>A name or user ID of the user (or automated user) that generated the
 build. There are no requirements on the specific format of this field, except
 that it MUST NOT be null or the empty string ("").</td>
 </tr>
 </tbody>
 </table>
 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4>
 <p>Android uses Intents to achieve loosely-coupled integration between
 applications. This section describes requirements related to the Intent
 patterns that MUST be honored by device implementations. By "honored", it is
 meant that the device implementer MUST provide an Android Activity or Service
 that specifies a matching Intent filter and binds to and implements correct
 behavior for each specified Intent pattern.</p>
 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4>
 <p>The Android upstream project defines a number of core applications, such as
 a phone dialer, calendar, contacts book, music player, and so on. Device
 implementers MAY replace these applications with alternative versions.</p>
 <p>However, any such alternative versions MUST honor the same Intent patterns
 provided by the upstream project. For example, if a device contains an
 alternative music player, it must still honor the Intent pattern issued by
 third-party applications to pick a song.</p>
 <p>The following applications are considered core Android system
 applications:</p>
 <ul>
 <li>Desk Clock</li>
 <li>Browser</li>
 <li>Calendar</li>
 <li>Calculator</li>
 <li>Camera</li>
 <li>Contacts</li>
 <li>Email</li>
 <li>Gallery</li>
 <li>GlobalSearch</li>
 <li>Launcher</li>
 <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted
 if the device does not support Live Wallpapers, per Section 3.8.5.)</li>
 <li>Messaging (AKA "Mms")</li>
 <li>Music</li>
 <li>Phone</li>
 <li>Settings</li>
 <li>SoundRecorder</li>
 </ul>
 <p>The core Android system applications include various Activity, or Service
 components that are considered "public".
 That is, the attribute "android:exported" may be absent, or may have the value
 "true".</p>
 <p>For every Activity or Service defined
 in one of the core Android system apps that is not marked as non-public via an
 android:exported attribute with the value "false", device implementations MUST
 include a compontent of the same type implementing the same Intent filter
 patterns as the core Android system app.</p>
 <p>In other words, a device implementation MAY replace core Android system
 apps; however, if it does, the device implementation MUST support all Intent
 patterns defined by each core Android system app being replaced.</p>
 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4>
 <p>As Android is an extensible platform, device implementers MUST allow each
 Intent pattern referenced in Section 3.2.3.1 to be overridden by third-party
 applications. The upstream Android open source project allows this by default;
 device implementers MUST NOT attach special privileges to system applications'
 use of these Intent patterns, or prevent third-party applications from binding
 to and assuming control of these patterns. This prohibition specifically
 includes but is not limited to disabling the "Chooser" user interface which
 allows the user to select between multiple applications which all handle the
 same Intent pattern.</p>
 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4>
 <p>Device implementers MUST NOT include any Android component that honors any
 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other
 key string in the android.* namespace.  Device implementers MUST NOT include
 any Android components that honor any new Intent or Broadcast Intent patterns
 using an ACTION, CATEGORY, or other key string in a package space belonging to
 another organization. Device implementers MUST NOT alter or extend any of the
 Intent patterns used by the core apps listed in Section 3.2.3.1.</p>
 <p>This prohibition is analogous to that specified for Java language classes
 in Section 3.6.</p>
 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4>
 <p>Third-party applications rely on the platform to broadcast certain Intents
 to notify them of changes in the hardware or software environment.
 Android-compatible devices MUST broadcast the public broadcast Intents in
 response to appropriate system events. Broadcast Intents are described in the
 SDK documentation.</p>

 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3>
 <p>Managed code running in Dalvik can call into native code provided in the
 application .apk file as an ELF .so file compiled for the appropriate device
 hardware architecture. Device implementations MUST include support for code
 running in the managed environment to call into native code, using the
 standard Java Native Interface (JNI) semantics. The following APIs MUST be
 available to native code:</p>
 <ul>
 <li>libc (C library)</li>
 <li>libm (math library)</li>
 <li>JNI interface</li>
 <li>libz (Zlib compression)</li>
 <li>liblog (Android logging)</li>
 <li>Minimal support for C++</li>
 <li>Support for OpenGL, as described below</li>
 </ul>
 <p>Device implementations MUST support OpenGL ES 1.0. Devices that lack
 hardware acceleration MUST implement OpenGL ES 1.0 using a software renderer.
 Device implementations SHOULD implement as much of OpenGL ES 1.1 as the device
 hardware supports.  Device implementations SHOULD provide an implementation
 for OpenGL ES 2.0, if the hardware is capable of reasonable performance on
 those APIs.</p>
 <p>These libraries MUST be source-compatible (i.e. header compatible) and
 binary-compatible (for a given processor architecture) with the versions
 provided in Bionic by the Android Open Source project. Since the Bionic
 implementations are not fully compatible with other implementations such as
 the GNU C library, device implementers SHOULD use the Android implementation.
 If device implementers use a different implementation of these libraries, they
 MUST ensure header, binary, and behavioral compatibility.</p>
 <p>Device implementations MUST accurately report the native Application Binary
 Interface (ABI) supported by the device, via the
 <code>android.os.Build.CPU_ABI</code> API. The ABI MUST be one of the entries
 documented in the latest version of the Android NDK, in the file
 <code>docs/CPU-ARCH-ABIS.txt</code>. Note that additional releases of the
 Android NDK may introduce support for additional ABIs.</p>
 <p>Native code compatibility is challenging. For this reason, it should be
 repeated that device implementers are VERY strongly encouraged to use the
 upstream implementations of the libraries listed above to help ensure
 compatibility.</p>

 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3>
 <p>Many developers and applications rely on the behavior of the
 <code>android.webkit.WebView</code> class [<a
 href="#resources08">Resources, 8</a>]
 for their user interfaces, so the WebView implementation must be
 compatible across Android implementations. Similarly, a full web experience is
 central to the Android user experience. Device implementations MUST include a
 version of <code>android.webkit.WebView</code> consistent with the upstream
 Android software, and MUST include a modern HTML5-capable browser, as
 described below.</p>
 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4>
 <p>The Android Open Source implementation uses the WebKit rendering engine to
 implement the <code>android.webkit.WebView</code>. Because it is not feasible
 to develop a comprehensive test suite for a web rendering system, device
 implementers MUST use the specific upstream build of WebKit in the WebView
 implementation.  Specifically:</p>
 <ul>
 <li>Device implementations' <code>android.webkit.WebView</code>
 implementations MUST be based on the 533.1 WebKit build from the upstream
 Android Open Source tree for Android 2.2. This build includes a specific set
 of functionality and security fixes for the WebView. Device implementers MAY
 include customizations to the WebKit implementation; however, any such
 customizations MUST NOT alter the behavior of the WebView, including rendering
 behavior.</li>
 <li>The user agent string reported by the WebView MUST be in this format:<br/>
     <code>Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1</code>
   <ul>
   <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li>
   <li>The value of the $(LOCALE) string SHOULD follow the ISO conventions for country code and language, and SHOULD refer to the current configured locale of the device</li>
   <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li>
   <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li>
   </ul></li>
 </ul>
 <p>The WebView configuration MUST include support for the HTML5 database,
 application cache, and geolocation APIs [<a href="#resources09">Resources,
 9</a>]. The WebView MUST include support for the HTML5
 <code>&lt;video&gt;</code> tag. HTML5 APIs, like all JavaScript APIs, MUST be
 disabled by default in a WebView, unless the developer explicitly enables them
 via the usual Android APIs.</p>
 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4>
 <p>Device implementations MUST include a standalone Browser application for
 general user web browsing. The standalone Browser MAY be based on an
 browser technology other than WebKit. However, even if an alternate Browser
 application is shipped, the <code>android.webkit.WebView</code> component
 provided to third-party applications MUST be based on WebKit, as described in
 Section 3.4.1.</p>
 <p>Implementations MAY ship a custom user agent string in the standalone
 Browser application.</p>
 <p>The standalone Browser application (whether based on the upstream
 WebKit Browser application or a third-party replacement) SHOULD include support
 for as much of HTML5 [<a href="#resources09">Resources, 9</a>] as possible.
 Minimally, device implementations MUST support HTML5 geolocation, application
 cache, and database APIs and the &lt;video&gt; tag in standalone the Browser
 application.</p>

 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3>
 <p>The behaviors of each of the API types (managed, soft, native, and web)
 must be consistent with the preferred implementation of the upstream Android
 open-source project [<a href="#resources03">Resources, 3</a>]. Some specific areas
 of compatibility are:</p>
 <ul>
 <li>Devices MUST NOT change the behavior or meaning of a standard Intent</li>
 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular type of system component (such as Service, Activity, ContentProvider, etc.)</li>
 <li>Devices MUST NOT change the semantics of a particular permission</li>
 </ul>
 <p>The above list is not comprehensive, and the onus is on device implementers
 to ensure behavioral compatibility. For this reason, device implementers
 SHOULD use the source code available via the Android Open Source Project where
 possible, rather than re-implement significant parts of the system.</p>
 <p>The Compatibility Test Suite (CTS) tests significant portions of the
 platform for behavioral compatibility, but not all. It is the responsibility
 of the implementer to ensure behavioral compatibility with the Android Open
 Source Project.</p>

 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3>
 <p>Android follows the package and class namespace conventions defined by the
 Java programming language. To ensure compatibility with third-party
 applications, device implementers MUST NOT make any prohibited modifications
 (see below) to these package namespaces:</p>
 <ul>
 <li>java.*</li>
 <li>javax.*</li>
 <li>sun.*</li>
 <li>android.*</li>
 <li>com.android.*</li>
 </ul>
 <p>Prohibited modifications include:</p>
 <ul>
 <li>Device implementations MUST NOT modify the publicly exposed APIs on the
 Android platform by changing any method or class signatures, or by removing
 classes or class fields.</li>
 <li>Device implementers MAY modify the underlying implementation of the APIs,
 but such modifications MUST NOT impact the stated behavior and Java-language
 signature of any publicly exposed APIs.</li>
 <li>Device implementers MUST NOT add any publicly exposed elements (such as
 classes or interfaces, or fields or methods to existing classes or interfaces)
 to the APIs above.</li>
 </ul>
 <p>A "publicly exposed element" is any construct which is not decorated with
 the "@hide" marker in the upstream Android source code. In other words, device
 implementers MUST NOT expose new APIs or alter existing APIs in the namespaces
 noted above. Device implementers MAY make internal-only modifications, but
 those modifications MUST NOT be advertised or otherwise exposed to
 developers.</p>
 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a
 namespace owned by or referring to another organization. For instance, device
 implementers MUST NOT add APIs to the com.google.* or similar namespace; only
 Google may do so. Similarly, Google MUST NOT add APIs to other companies'
 namespaces.</p>
 <p>If a device implementer proposes to improve one of the package namespaces
 above (such as by adding useful new functionality to an existing API, or
 adding a new API), the implementer SHOULD visit source.android.com and begin
 the process for contributing changes and code, according to the information on
 that site.</p>
 <p>Note that the restrictions above correspond to standard conventions for
 naming APIs in the Java programming language; this section simply aims to
 reinforce those conventions and make them binding through inclusion in this
 compatibility definition.</p>

 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3>
 <p>Device implementations MUST support the full Dalvik Executable (DEX)
 bytecode specification and Dalvik Virtual Machine semantics [<a
 href="#resources10">Resources, 10</a>].</p>
 <p>Device implementations with screens classified as medium- or low-density
 MUST configure Dalvik to allocate at least 16MB of memory to each application.
 Device implementations with screens classified as high-density MUST configure
 Dalvik to allocate at least 24MB of memory to each application. Note that
 device implementations MAY allocate more memory than these figures.</p>

 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3>
 <p>The Android platform includes some developer APIs that allow developers to
 hook into the system user interface. Device implementations MUST incorporate
 these standard UI APIs into custom user interfaces they develop, as explained
 below.</p>
 <a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4>
 <p>Android defines a component type and corresponding API and lifecycle that
 allows applications to expose an "AppWidget" to the end user [<a
 href="#resources11">Resources, 11</a>].
 The Android Open Source reference release includes a Launcher application that
 includes user interface elements allowing the user to add, view, and remove
 AppWidgets from the home screen.</p>
 <p>Device implementers MAY substitute an alternative to the reference Launcher
 (i.e. home screen).  Alternative Launchers SHOULD include built-in support for
 AppWidgets, and expose user interface elements to add, configure, view, and remove
 AppWidgets directly within the Launcher. Alternative Launchers MAY omit these
 user interface elements; however, if they are omitted, the device implementer
 MUST provide a separate application accessible from the Launcher that allows
 users to add, configure, view, and remove AppWidgets.</p>
 <a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4>
 <p>Android includes APIs that allow developers to notify users of notable
 events [<a href="#resources12">Resources, 12</a>]. Device implementers MUST provide support for each
 class of notification so defined; specifically: sounds, vibration, light and
 status bar.</p>
 <p>Additionally, the implementation MUST correctly render all resources
 (icons, sound files, etc.) provided for in the APIs [<a
 href="#resources13">Resources, 13</a>], or in the
 Status Bar icon style guide [<a href="#resources14">Resources, 14</a>]. Device implementers MAY provide
 an alternative user experience for notifications than that provided by the
 reference Android Open Source implementation; however, such alternative
 notification systems MUST support existing notification resources, as
 above.</p>
 <a name="section-3.8.3"></a><h4>3.8.3. Search</h4>
 <p>Android includes APIs [<a href="#resources15">Resources, 15</a>] that allow developers to incorporate
 search into their applications, and expose their application's data into the
 global system search. Generally speaking, this functionality consists of a
 single, system-wide user interface that allows users to enter queries,
 displays suggestions as users type, and displays results. The Android APIs
 allow developers to reuse this interface to provide search within their own
 apps, and allow developers to supply results to the common global search user
 interface.</p>
 <p>Device implementations MUST include a single, shared, system-wide search
 user interface capable of real-time suggestions in response to user input.
 Device implementations MUST implement the APIs that allow developers to reuse
 this user interface to provide search within their own applications.  Device
 implementations MUST implement the APIs that allow third-party applications to
 add suggestions to the search box when it is run in global search mode. If no
 third-party applications are installed that make use of this functionality,
 the default behavior SHOULD be to display web search engine results and
 suggestions.</p>
 <p>Device implementations MAY ship alternate search user interfaces, but
 SHOULD include a hard or soft dedicated search button, that can be used at any
 time within any app to invoke the search framework, with the behavior provided
 for in the API documentation.</p>
 <a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4>
 <p>Applications can use the "Toast" API (defined in [<a
 href="#resources16">Resources, 16</a>]) to
 display short non-modal strings to the end user, that disappear after a brief
 period of time. Device implementations MUST display Toasts from applications
 to end users in some high-visibility manner.</p>
 <a name="section-3.8.5"></a><h4>3.8.5. Live Wallpapers</h4>
 <p>Android defines a component type and corresponding API and lifecycle that
 allows applications to expose one or more "Live Wallpapers" to the end user
 [<a href="#resources17">Resources, 17</a>]. Live Wallpapers are animations,
 patterns, or similar images with limited input capabilities that display as a
 wallpaper, behind other applications.</p>
 <p>Hardware is considered capable of reliably running live wallpapers if it
 can run all live wallpapers, with no limitations on functionality, at a
 reasonable framerate with no adverse affects on other applications. If
 limitations in the hardware cause wallpapers and/or applications to crash,
 malfunction, consume excessive CPU or battery power, or run at unacceptably
 low frame rates, the hardware is considered incapable of running live
 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0
 context to render their content. Live wallpaper will not run reliably on
 hardware that does not support multiple OpenGL contexts because the live
 wallpaper use of an OpenGL context may conflict with other applications that
 also use an OpenGL context. </p>
 <p>Device implementations capable of running live wallpapers reliably as
 described above SHOULD implement live wallpapers. Device implementations
 determined to not run live wallpapers reliably as described above MUST NOT
 implement live wallpapers.</p>

 <a name="section-4"></a><h2>4. Reference Software Compatibility</h2>
 <p>Device implementers MUST test implementation compatibility using the
 following open-source applications:</p>
 <ul>
 <li>Calculator (included in SDK)</li>
 <li>Lunar Lander (included in SDK)</li>
 <li>The "Apps for Android" applications [<a href="#resources18">Resources, 18</a>].</li>
 <li>Replica Island (available in Android Market; only required for device
     implementations that support with OpenGL ES 2.0)</li>
 </ul>
 <p>Each app above MUST launch and behave correctly on the implementation, for
 the implementation to be considered compatible.</p>
 <p>Additionally, device implementations MUST test each menu item (including all
 sub-menus) of each of these smoke-test applications:</p>
 <ul>
 <li>ApiDemos (included in SDK)</li>
 <li>ManualSmokeTests (included in CTS)</li>
 </ul>
 <p>Each test case in the applications above MUST run correctly on the device
 implementation.</p>

 <a name="section-5"></a><h2>5. Application Packaging Compatibility</h2>
 <p>Device implementations MUST install and run Android ".apk" files as
 generated by the "aapt" tool included in the official Android SDK [<a
 href="#resources19">Resources, 19</a>].</p>
 <p>Devices implementations MUST NOT extend either the .apk [<a
 href="#resources20">Resources, 20</a>], Android Manifest [<a
 href="#resources21">Resources, 21</a>],
 or Dalvik bytecode [<a href="#resources10">Resources, 10</a>] formats in such
 a way that would prevent those files from
 installing and running correctly on other compatible devices. Device
 implementers SHOULD use the reference upstream implementation of Dalvik, and
 the reference implementation's package management system.</p>

 <a name="section-6"></a><h2>6. Multimedia Compatibility</h2>
 <p>Device implementations MUST fully implement all multimedia APIs. Device
 implementations MUST include support for all multimedia codecs described
 below, and SHOULD meet the sound processing guidelines described below.</p>
 <a name="section-6.1"></a><h3>6.1. Media Codecs</h3>
 <p>Device implementations MUST support the following multimedia codecs. All of
 these codecs are provided as software implementations in the preferred Android
 implementation from the Android Open Source Project.</p>
 <p>Please note that neither Google nor the Open Handset Alliance make any
 representation that these codecs are unencumbered by third-party patents.
 Those intending to use this source code in hardware or software products are
 advised that implementations of this code, including in open source software
 or shareware, may require patent licenses from the relevant patent
 holders.</p>
 <table><tbody>
 <tr>
 <td rowspan="11"><b>Audio</b></td>
 </tr>
 <tr>
 <td><b>Name</b></td>
 <td><b>Encoder</b></td>
 <td><b>Decoder</b></td>
 <td><b>Details</b></td>
 <td><b>File/Container Format</b></td>
 </tr>
 <tr>
 <td>AAC LC/LTP</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td rowspan="3">Mono/Stereo content in any combination of standard bit rates up to 160 kbps and sampling rates between 8 to 48kHz</td>
 <td rowspan="3">3GPP (.3gp) and MPEG-4 (.mp4, .m4a). No support for raw AAC (.aac)</td>
 </tr>
 <tr>
 <td>HE-AACv1 (AAC+)</td>
 <td>&nbsp;</td>
 <td>X</td>
 </tr>
 <tr>
 <td>HE-AACv2 (enhanced AAC+)</td>
 <td>&nbsp;</td>
 <td>X</td>
 </tr>
 <tr>
 <td>AMR-NB</td>
 <td>X</td>
 <td>X</td>
 <td>4.75 to 12.2 kbps sampled @ 8kHz</td>
 <td>3GPP (.3gp)</td>
 </tr>
 <tr>
 <td>AMR-WB</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td>
 <td>3GPP (.3gp)</td>
 </tr>
 <tr>
 <td>MP3</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR)</td>
 <td>MP3 (.mp3)</td>
 </tr>
 <tr>
 <td>MIDI</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for ringtone formats RTTTL/RTX, OTA, and iMelody</td>
 <td>Type 0 and 1 (.mid, .xmf, .mxmf). Also RTTTL/RTX (.rtttl, .rtx), OTA (.ota), and iMelody (.imy)</td>
 </tr>
 <tr>
 <td>Ogg Vorbis</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>Ogg (.ogg)</td>
 </tr>
 <tr>
 <td>PCM</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>8- and 16-bit linear PCM (rates up to limit of hardware)</td>
 <td>WAVE (.wav)</td>
 </tr>
 <tr>
 <td rowspan="5"><b>Image</b></td>
 </tr>
 <tr>
 <td>JPEG</td>
 <td>X</td>
 <td>X</td>
 <td>base+progressive</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>GIF</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>PNG</td>
 <td>X</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>BMP</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td rowspan="4"><b>Video</b></td>
 </tr>
 <tr>
 <td>H.263</td>
 <td>X</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>3GPP (.3gp) files</td>
 </tr>
 <tr>
 <td>H.264</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>3GPP (.3gp) and MPEG-4 (.mp4) files</td>
 </tr>
 <tr>
 <td>MPEG4 Simple Profile</td>
 <td>&nbsp;</td>
 <td>X</td>
 <td>&nbsp;</td>
 <td>3GPP (.3gp) file</td>
 </tr>
 </tbody>
 </table>
 <p>Note that the table above does not list specific bitrate requirements for
 most video codecs. The reason for this is that in practice, current device
 hardware does not necessarily support bitrates that map exactly to the
 required bitrates specified by the relevant standards. Instead, device
 implementations SHOULD support the highest bitrate practical on the hardware,
 up to the limits defined by the specifications.</p>

 <a name="section-6.2"></a><h3>6.2. Audio Recording</h3>
 <p>When an application has used the <code>android.media.AudioRecord</code> API to
 start recording an audio stream, device implementations SHOULD sample and
 record audio with each of these behaviors:</p>
 <ul>
 <li>Noise reduction processing, if present, SHOULD be disabled.</li>
 <li>Automatic gain control, if present, SHOULD be disabled.</li>
 <li>The device SHOULD exhibit approximately flat amplitude versus frequency
     characteristics; specifically, &plusmn;3 dB, from 100 Hz to 4000 Hz</li>
 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level
     (SPL) source at 1000 Hz yields RMS of 5000 for 16-bit samples.</li>
 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least
     a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li>
 <li>Total harmonic distortion SHOULD be less than 1% from 100 Hz to 4000 Hz at
     90 dB SPL input level.</li>
 </ul>
 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD"
 for Android 2.2, the Compatibility Definition for a future version is planned
 to change these to "MUST". That is, these requirements are optional in Android
 2.2 but <b>will be required</b> by a future version. Existing and new devices
 that run Android 2.2 Android are <b>very strongly encouraged to meet
 these requirements in Android 2.2</b>, or they will not be able to attain
 Android compatibility when upgraded to the future version.</p>

 <a name="section-6.3"></a><h3>6.3. Audio Latency</h3>
 <p>Audio latency is broadly defined as the interval between when an
 application requests an audio playback or record operation, and when the
 device implementation actually begins the operation. Many classes of
 applications rely on short latencies, to achieve real-time effects such sound
 effects or VOIP communication. Device implementations SHOULD meet all audio
 latency requirements outlined in this section.</p>
 <p>For the purposes of this section:</p>
 <ul>
 <li>"cold output latency" is defined to be the interval between when an
     application requests audio playback and when sound begins playing, when
     the audio system has been idle and powered down prior to the request</li>
 <li>"warm output latency" is defined to be the interval between when an
     application requests audio playback and when sound begins playing, when
     the audio system has been recently used but is currently idle (that is,
     silent)</li>
 <li>"continuous output latency" is defined to be the interval between when an
     application issues a sample to be played and when the speaker physically
     plays the corresponding sound, while the device is currently playing back
     audio</li>
 <li>"cold input latency" is defined to be the interval between when an
     application requests audio recording and when the first sample is
     delivered to the application via its callback, when the audio system and
     microphone has been idle and powered down prior to the request</li>
 <li>"continuous input latency" is defined to be when an ambient sound occurs
     and when the sample corresponding to that sound is delivered to a
     recording application via its callback, while the device is in recording
     mode</li>
 </ul>
 <p>Using the above definitions, device implementations SHOULD exhibit each of
 these properties:</p>
 <ul>
 <li>cold output latency of 100 milliseconds or less</li>
 <li>warm output latency of 10 milliseconds or less</li>
 <li>continuous output latency of 45 milliseconds or less</li>
 <li>cold input latency of 100 milliseconds or less</li>
 <li>continuous input latency of 50 milliseconds or less</li>
 </ul>
 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD"
 for Android 2.2, the Compatibility Definition for a future version is planned
 to change these to "MUST". That is, these requirements are optional in Android
 2.2 but <b>will be required</b> by a future version. Existing and new devices
 that run Android 2.2 Android are <b>very strongly encouraged to meet
 these requirements in Android 2.2</b>, or they will not be able to attain
 Android compatibility when upgraded to the future version.</p>

 <a name="section-7"></a><h2>7. Developer Tool Compatibility</h2>
 <p>Device implementations MUST support the Android Developer Tools provided in
 the Android SDK. Specifically, Android-compatible devices MUST be compatible
 with:</p>
 <ul>
 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources19">Resources, 19</a>]<br/>
 Device implementations MUST support all <code>adb</code> functions as
 documented in the Android SDK. The device-side <code>adb</code> daemon SHOULD
 be inactive by default, but there MUST be a user-accessible mechanism to turn
 on the Android Debug Bridge.</li>
 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources19">Resources, 19</a>]<br/>
 Device implementations MUST support all <code>ddms</code> features as documented in the
 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for
 <code>ddms</code> SHOULD be inactive by default,
 but MUST be supported whenever the user has activated the Android Debug
 Bridge, as above.</li>
 <li><b>Monkey</b> [<a href="#resources22">Resources, 22</a>]<br/>
 Device implementations MUST include the Monkey framework, and make it
 available for applications to use.</li>
 </ul>

 <a name="section-8"></a><h2>8. Hardware Compatibility</h2>
 <p>Android is intended to support device implementers creating innovative form
 factors and configurations.  At the same time Android developers expect
 certain hardware, sensors and APIs across all Android device. This section
 lists the hardware features that all Android 2.2 compatible devices must
 support.</p>
 <p>If a device includes a particular hardware component that has a
 corresponding API for third-party developers, the device implementation MUST
 implement that API as defined in the Android SDK documentation. If an API in
 the SDK interacts with a hardware component that is stated to be optional and the device
 implementation does not possess that component:</p>
 <ul>
 <li>class definitions for the component's APIs MUST be present</li>
 <li>the API's behaviors MUST be implemented as no-ops in some reasonable fashion</li>
 <li>API methods MUST return null values where permitted by the SDK documentation</li>
 <li>API methods MUST return no-op implementations of classes where null values are not permitted by the SDK documentation</li>
 </ul>
 <p>A typical example of a scenario where these requirements apply is the
 telephony API: even on non-phone devices, these APIs must be implemented as
 reasonable no-ops.</p>
 <p>Device implementations MUST accurately report accurate hardware configuration
 information via the <code>getSystemAvailableFeatures()</code> and
 <code>hasSystemFeature(String)</code> methods on the
 <code>android.content.pm.PackageManager</code> class. [<a
 href="#resources23">Resources, 23</a>]</p>

 <a name="section-8.1"></a><h3>8.1. Display</h3>
 <p>Android 2.2 includes facilities that perform certain automatic scaling and
 transformation operations under some circumstances, to ensure that third-party
 applications run reasonably well on a variety of hardware configurations [<a
 href="#resources24">Resources, 24</a>]. Devices MUST properly implement these
 behaviors, as detailed in this section.</p>
 <p>For Android 2.2, these are the most common display configurations:</p>
 <table><tbody>
 <tr>
 <td>Screen Type</td>
 <td>Width (Pixels)</td>
 <td>Height (Pixels)</td>
 <td>Diagonal Length Range (inches)</td>
 <td>Screen Size Group</td>
 <td>Screen Density Group</td>
 </tr>
 <tr>
 <td>QVGA</td>
 <td>240</td>
 <td>320</td>
 <td>2.6 - 3.0</td>
 <td>Small</td>
 <td>Low</td>
 </tr>
 <tr>
 <td>WQVGA</td>
 <td>240</td>
 <td>400</td>
 <td>3.2 - 3.5</td>
 <td>Normal</td>
 <td>Low</td>
 </tr>
 <tr>
 <td>FWQVGA</td>
 <td>240</td>
 <td>432</td>
 <td>3.5 - 3.8</td>
 <td>Normal</td>
 <td>Low</td>
 </tr>
 <tr>
 <td>HVGA</td>
 <td>320</td>
 <td>480</td>
 <td>3.0 - 3.5</td>
 <td>Normal</td>
 <td>Medium</td>
 </tr>
 <tr>
 <td>WVGA</td>
 <td>480</td>
 <td>800</td>
 <td>3.3 - 4.0</td>
 <td>Normal</td>
 <td>High</td>
 </tr>
 <tr>
 <td>FWVGA</td>
 <td>480</td>
 <td>854</td>
 <td>3.5 - 4.0</td>
 <td>Normal</td>
 <td>High</td>
 </tr>
 <tr>
 <td>WVGA </td>
 <td>480 </td>
 <td>800 </td>
 <td>4.8 - 5.5 </td>
 <td>Large </td>
 <td>Medium</td>
 </tr>
 <tr>
 <td>FWVGA</td>
 <td>480</td>
 <td>854</td>
 <td>5.0 - 5.8</td>
 <td>Large</td>
 <td>Medium</td>
 </tr>

 </tbody></table>

 <p>Device implementations corresponding to one of the standard configurations
 above MUST be configured to report the indicated screen size to applications
 via the <code>android.content.res.Configuration</code> [<a href="#resources25">Resources,
 24</a>] class.</p>
 <p>Some .apk packages have manifests that do not identify them as supporting a
 specific density range. When running such applications, the following
 constraints apply:</p>
 <ul>
 <li>Device implementations MUST interpret resources in a .apk that lack a
 density qualifier as defaulting to "medium" (known as "mdpi" in the SDK
 documentation.)</li>
 <li>When operating on a "low" density screen, device implementations MUST
 scale down medium/mdpi assets by a factor of 0.75.</li>
 <li>When operating on a "high" density screen, device implementations MUST
 scale up medium/mdpi assets by a factor of 1.5.</li>
 <li>Device implementations MUST NOT scale assets within a density range, and
 MUST scale assets by exactly these factors between density ranges.</li>
 </ul>

 <a name="section-8.1.2"></a><h4>8.1.2. Non-Standard Display Configurations</h4>
 <p>Display configurations that do not match one of the standard configurations
 listed in Section 8.1.1 require additional consideration and work to be
 compatible. Device implementers MUST contact Android Compatibility Team as
 described in Section 13 to obtain classifications for screen-size bucket,
 density, and scaling factor. When provided with this information, device
 implementations MUST implement them as specified.</p>
 <p>Note that some display configurations (such as very large or very small
 screens, and some aspect ratios) are fundamentally incompatible with Android
 2.2; therefore device implementers are encouraged to contact Android
 Compatibility Team as early as possible in the development process.</p>

 <a name="section-8.1.3"></a><h4>8.1.3. Display Metrics</h4>
 <p>Device implementations MUST report correct valuesfor all display metrics
 defined in <code>android.util.DisplayMetrics</code> [<a
 href="#resources26">Resources, 26</a>].</p>

 <a name="section-8.1.4"></a><h4>8.1.4. Declared Screen Support</h4>
 <p>Applications may indicate which screen sizes they support via the
 <code>&lt;supports-screens&gt;</code> attribute in the AndroidManifest.xml
 file. Device implementations MUST correctly honor applications' stated support
 for small, medium, and large screens, as described in the Android
 SDK documentation.</p>

 <a name="section-8.2"></a><h3>8.2. Keyboard</h3>
 <p>Device implementations:</p>
 <ul>
 <li>MUST include support for the Input Management Framework (which allows third party developers to create Input Management Engines -- i.e. soft keyboard) as detailed at developer.android.com</li>
 <li>MUST provide at least one soft keyboard implementation (regardless of whether a hard keyboard is present)</li>
 <li>MAY include additional soft keyboard implementations</li>
 <li>MAY include a hardware keyboard</li>
 <li>MUST NOT include a hardware keyboard that does not match one of the
 formats specified in <code>android.content.res.Configuration.keyboard</code>
 [<a href="#resources25">Resources, 25</a>] (that is, QWERTY, or 12-key)</li>
 </ul>
 <a name="section-8.3"></a><h3>8.3. Non-touch Navigation</h3>
 <p>Device implementations:</p>
 <ul>
 <li>MAY omit a non-touch navigation options (that is, may omit a trackball, d-pad, or wheel)</li>
 <li>MUST report the correct value for
 <code>android.content.res.Configuration.navigation</code> [<a href="#resources25">Resources, 25</a>]</li>
 </ul>
 <a name="section-8.4"></a><h3>8.4. Screen Orientation</h3>
 <p>Compatible devices MUST support dynamic orientation by applications to
 either portrait or landscape screen orientation. That is, the device must
 respect the application's request for a specific screen orientation. Device
 implementations MAY select either portrait or landscape orientation as the
 default.</p>
 <p>Devices MUST report the correct value for the device's current orientation,
 whenever queried via the android.content.res.Configuration.orientation,
 android.view.Display.getOrientation(), or other APIs.</p>

 <a name="section-8.5"></a><h3>8.5. Touchscreen input</h3>
 <p>Device implementations:</p>
 <ul>
 <li>MUST have a touchscreen</li>
 <li>MAY have either capacative or resistive touchscreen</li>
 <li>MUST report the value of <code>android.content.res.Configuration</code>
 [<a href="#resources25">Resources, 25</a>]
 reflecting corresponding to the type of the specific touchscreen on the
 device</li>
 <li>SHOULD support fully independently tracked pointers, if the touchscreen supports multiple pointers</li>
 </ul>

 <a name="section-8.6"></a><h3>8.6. USB</h3>
 <p>Device implementations:</p>
 <ul>
 <li>MUST implement a USB client, connectable to a USB host with a standard
 USB-A port</li>
 <li>MUST implement the Android Debug Bridge over USB (as described in Section
 7)</li>
 <li>MUST implement the USB mass storage specification, to allow a host
 connected to the device to access the contents of the /sdcard volume </li>
 <li>SHOULD use the micro USB form factor on the device side</li>
 <li>MAY include a non-standard port on the device side, but if so MUST ship
 with a cable capable of connecting the custom pinout to standard USB-A
 port</li>
 <li>SHOULD implement support for the USB Mass Storage specification (so that
 either removable or fixed storage on the device can be accessed from a host
 PC)</li>
 </ul>

 <a name="section-8.7"></a><h3>8.7. Navigation keys</h3>
 <p>The Home, Menu and Back functions are essential to the Android navigation
 paradigm. Device implementations MUST make these functions available to the
 user at all times, regardless of application state. These functions SHOULD be
 implemented via dedicated buttons. They MAY be implemented using software,
 gestures, touch panel, etc., but if so they MUST be always accessible and not
 obscure or interfere with the available application display area.</p>
 <p>Device implementers SHOULD also provide a dedicated search key. Device
 implementers MAY also provide send and end keys for phone calls.</p>

 <a name="section-8.8"></a><h3>8.8. Wireless Data Networking</h3>
 <p>Device implementations MUST include support for wireless high-speed data
 networking. Specifically, device implementations MUST include support for at
 least one wireless data standard capable of 200Kbit/sec or greater. Examples of
 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, etc.</p>
 <p>If a device implementation includes a particular modality for which the
 Android SDK includes an API (that is, WiFi, GSM, or CDMA), the implementation
 MUST support the API.</p>
 <p>Devices MAY implement more than one form of wireless data connectivity.
 Devices MAY implement wired data connectivity (such as Ethernet), but MUST
 nonetheless include at least one form of wireless connectivity, as above.</p>

 <a name="section-8.9"></a><h3>8.9. Camera</h3>
 <p>Device implementations MUST include a rear-facing camera. The included
 rear-facing camera:</p>
 <ul>
 <li>MUST have a resolution of at least 2 megapixels</li>
 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented
 in the camera driver (transparent to application software)</li>
 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li>
 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST
 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been
 registered on a Camera preview surface, unless the application has explicitly
 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or
 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code>
 object. Note that this constraint does not apply to the device's built-in
 system camera application, but only to third-party applications using
 <code>Camera.PreviewCallback</code>.</li>
 </ul>
 <p>Device implementations MUST implement the following behaviors for the
 camera-related APIs:</p>
 <ol>
 <li>If an application has never called
 android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST
 use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to
 application callbacks.</li>
 <li>If an application registers an android.hardware.Camera.PreviewCallback
 instance and the system calls the onPreviewFrame() method when the preview
 format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame()
 must further be in the NV21 encoding format. (This is the format used natively
 by the 7k hardware family.) That is, NV21 MUST be the default.</li>
 </ol>
 <p>Device implementations MUST implement the full Camera API included in the
 Android 2.2 SDK documentation [<a href="#resources27">Resources, 27</a>]),
 regardless of whether the device includes hardware autofocus or other
 capabilities. For instance, cameras that lack autofocus MUST still call any
 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though
 this has no relevance to a non-autofocus camera.)</p>
 <p>Device implementations MUST recognize and honor each parameter name defined
 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the
 underlying hardware supports the feature. If the device hardware does not
 support a feature, the API must behave as documented. Conversely, Device
 implementations MUST NOT honor or recognize string constants passed
 to the <code>android.hardware.Camera.setParameters()</code> method other than
 those documented as constants on the
 <code>android.hardware.Camera.Parameters</code>.  That is,
 device implementations MUST support all standard Camera parameters if the
 hardware allows, and MUST NOT support custom Camera parameter types.</p>
 <p>Device implementations MAY include a front-facing camera. However, if
 a device implementation includes a front-facing camera, the camera API as
 implemented on the device MUST NOT use the front-facing camera by default.
 That is, the camera API in Android 2.2 is for rear-facing cameras only, and
 device implementations MUST NOT reuse or overload the API to act on a
 front-facing camera, if one is present. Note that any custom APIs added by
 device implementers to support front-facing cameras MUST abide by sections 3.5
 and 3.6; for instance, if a custom <code>android.hardware.Camera</code> or
 <code>Camera.Parameters</code> subclass is provided to support front-facing
 cameras, it MUST NOT be located in an existing namespace, as described by
 sections 3.5 and 3.6. Note that the inclusion of a front-facing camera does
 not meet the requirement that devices include a rear-facing camera.</p>

 <a name="section-8.10"></a><h3>8.10. Accelerometer</h3>
 <p>Device implementations MUST include a 3-axis accelerometer and MUST be able
 to deliver events at 50 Hz or greater. The coordinate system used by the
 accelerometer MUST comply with the Android sensor coordinate system as detailed
 in the Android APIs (see [<a href="#resources28">Resources, 28</a>]).</p>

 <a name="section-8.11"></a><h3>8.11. Compass</h3>
 <p>Device implementations MUST include a 3-axis compass and MUST be able to
 deliver events 10 Hz or greater. The coordinate system used by the compass
 MUST comply with the Android sensor coordinate system as defined in the Android
 API (see [<a href="#resources28">Resources, 28</a>]).</p>

 <a name="section-8.12"></a><h3>8.12. GPS</h3>
 <p>Device implementations MUST include a GPS receiver, and SHOULD include
 some form of "assisted GPS" technique to minimize GPS lock-on time.</p>

 <a name="section-8.13"></a><h3>8.13. Telephony</h3>
 <p>Android 2.2 MAY be used on devices that do not include telephony hardware.
 That is, Android 2.2 is compatible with devices that are not phones.
 However, if a device implementation does include GSM or CDMA telephony, it
 MUST implement the full support for the API for that technology. Device
 implementations that do not include telephony hardware MUST implement the full
 APIs as no-ops.</p>
 <p>See also Section 8.8, Wireless Data Networking.</p>

 <a name="section-8.14"></a><h3>8.14. Memory and Storage</h3>
 <p>Device implementations MUST have at least 92MB of memory available to the
 kernel and userspace. The 92MB MUST be in addition to any memory dedicated to
 hardware components such as radio, memory, and so on that is not under the
 kernel's control.</p>
 <p>Device implementations MUST have at least 150MB of non-volatile storage
 available for user data. That is, the <code>/data</code> partition MUST be at
 least 150MB.</p>
 <p>Beyond the requirements above, device implementations SHOULD have at least
 128MB of memory available to kernel and userspace, in addition to any memory
 dedicated to hardware components that is not under the kernel's control.
 Device implementations SHOULD have at least 1GB of non-volatile storage
 available for user data. Note that these higher requirements are planned to
 become hard minimums in a future version of Android. Device implementations are
 strongly encouraged to meet these requirements now, or else they may not be
 eligible for compatibility for a future version of Android.</p>

 <a name="section-8.15"></a><h3>8.15. Application Shared Storage</h3>
 <p>Device implementations MUST offer shared storage for applications. The
 shared storage provided MUST be at least 2GB in size.</p>
 <p>Device implementations MUST be configured with shared storage mounted by
 default, "out of the box". If the shared storage is not mounted on the Linux
 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link
 from <code>/sdcard</code> to the actual mount point.</p>
 <p>Device implementations MUST enforce as documented the
 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this
 shared storage. Shared storage MUST otherwise be writable by any application
 that obtains that permission.</p>
 <p>Device implementations MAY have hardware for user-accessible removable
 storage, such as a Secure Digital card. Alternatively, device implementations
 MAY allocate internal (non-removable) storage as shared storage for apps.</p>
 <p>Regardless of the form of shared storage used, the shared storage MUST
 implement USB mass storage, as described in Section 8.6. As shipped out of the
 box, the shared storage MUST be mounted with the FAT filesystem.</p>
 <p>It is illustrative to consider two common examples. If a device
 implementation includes an SD card slot to satisfy the shared storage
 requirement, a FAT-formatted SD card 2GB in size or larger MUST be included
 with the device as sold to users, and MUST be mounted by default.
 Alternatively, if a device implementation uses internal fixed storage to
 satisfy this requirement, that storage MUST be 2GB in size or larger,
 formatted as FAT, and mounted on <code>/sdcard</code> (or <code>/sdcard</code>
 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p>
 <p>Device implementations that include multiple shared storage paths (such as
 both an SD card slot and shared internal storage) SHOULD modify the core
 applications such as the media scanner and ContentProvider to transparently
 support files placed in both locations.</p>

 <a name="section-8.16"></a><h3>8.16. Bluetooth</h3>
 <p>Device implementations MUST include a Bluetooth transceiver. Device
 implementations MUST enable the RFCOMM-based Bluetooth API as described in the
 SDK documentation [<a href="#resources30">Resources, 30</a>]. Device
 implementations SHOULD implement relevant Bluetooth profiles, such as A2DP,
 AVRCP, OBEX, etc. as appropriate for the device.</p>
 <p>The Compatibility Test Suite includes cases that cover basic operation of
 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications
 protocol between devices, it cannot be fully tested by unit tests running on a
 single device. Consequently, device implementations MUST also pass the
 human-driven Bluetooth test procedure described in Appendix A.</p>

 <a name="section-9"></a><h2>9. Performance Compatibility</h2>
 <p>One of the goals of the Android Compatibility Program is to enable
 consistent application experience to consumers. Compatible implementations
 must ensure not only that applications simply run correctly on the device, but
 that they do so with reasonable performance and overall good user experience.
 Device implementations MUST meet the key performance metrics of an Android 2.2
 compatible device defined in the table below:</p>
 <table><tbody><tr>
 <td><b>Metric</b></td>
 <td><b>Performance Threshold</b></td>
 <td><b>Comments</b></td>
 </tr>
 <tr>
 <td>Application Launch Time</td>
 <td>The following applications should launch within the specified time.<ul>
 <li>Browser: less than 1300ms</li>
 <li>MMS/SMS: less than 700ms</li>
 <li>AlarmClock: less than 650ms</li>
 </ul></td>
 <td>The launch time is measured as the total time to
 complete loading the default activity for the application, including the time
 it takes to start the Linux process, load the Android package into the Dalvik
 VM, and call onCreate.</td>
 </tr>
 <tr>
 <td>Simultaneous Applications</td>
 <td>When multiple applications have been launched, re-launching an
 already-running application after it has been launched must take less than the
 original launch time.</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
 </table>

 <a name="section-10"></a><h2>10. Security Model Compatibility</h2>
 <p>Device implementations MUST implement a security model consistent with the
 Android platform security model as defined in Security and Permissions
 reference document in the APIs [<a href="#resources29">Resources, 29</a>] in the
 Android developer documentation. Device implementations MUST support
 installation of self-signed applications without requiring any additional
 permissions/certificates from any third parties/authorities.  Specifically,
 compatible devices MUST support the security mechanisms described in the
 follow sub-sections.</p>
 <a name="section-10.1"></a><h3>10.1. Permissions</h3>
 <p>Device implementations MUST support the Android permissions model as
 defined in the Android developer documentation [<a
 href="#resources29">Resources, 29</a>]. Specifically,
 implementations MUST enforce each permission defined as described in the SDK
 documentation; no permissions may be omitted, altered, or ignored.
 Implementations MAY add additional permissions, provided the new permission ID
 strings are not in the android.* namespace.</p>
 <a name="section-10.2"></a><h3>10.2. UID and Process Isolation</h3>
 <p>Device implementations MUST support the Android application sandbox model,
 in which each application runs as a unique Unix-style UID and in a separate
 process.  Device implementations MUST support running multiple applications as
 the same Linux user ID, provided that the applications are properly signed and
 constructed, as defined in the Security and Permissions reference [<a
 href="#resources29">Resources, 29</a>].</p>
 <a name="section-10.3"></a><h3>10.3. Filesystem Permissions</h3>
 <p>Device implementations MUST support the Android file access permissions
 model as defined in as defined in the Security and Permissions reference [<a
 href="#resources29">Resources, 29</a>].</p>
 <a name="section-10.4"></a><h3>10.4. Alternate Execution Environments</h3>
 <p>Device implementations MAY include runtime environments that execute
 applications using some other software or technology than the Dalvik virtual
 machine or native code. However, such alternate execution environments MUST
 NOT compromise the Android security model or the security of installed Android
 applications, as described in this section.</p>
 <p>Alternate runtimes MUST themselves be Android applications, and abide by
    the standard Android security model, as described elsewhere in Section 10.</p>
 <p>Alternate runtimes MUST NOT be granted access to resources protected by
    permissions not requested in the runtime's AndroidManifest.xml file via the
    <code>&lt;uses-permission&gt;</code> mechanism.</p>
 <p>Alternate runtimes MUST NOT permit applications to make use of features
    protected by Android permissions restricted to system applications.</p>
 <p>Alternate runtimes MUST abide by the Android sandbox model.  Specifically:</p>
 <ul>
 <li>Alternate runtimes SHOULD install apps via the PackageManager into
     separate Android sandboxes (that is, Linux user IDs, etc.)</li>
 <li>Alternate runtimes MAY provide a single Android sandbox shared by all
     applications using the alternate runtime.</li>
 <li>Alternate runtimes and installed applications using an alternate runtime
     MUST NOT reuse the sandbox of any other app installed on the device, except
     through the standard Android mechanisms of shared user ID and signing
     certificate</li>
 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to
     the sandboxes corresponding to other Android applications.</li>
 </ul>
 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other
    applications any privileges of the superuser (root), or of any other user ID.</p>
 <p>The .apk files of alternate runtimes MAY be included in the system image of
    a device implementation, but MUST be signed with a key distinct
    from the key used to sign other applications included with the device
    implementation.</p>
 <p>When installing applications, alternate runtimes MUST obtain user consent
    for the Android permissions used by the application. That is, if an
    application needs to make use of a device resource for which there is a
    corresponding Android permission (such as Camera, GPS, etc.), the alternate
    runtime MUST inform the user that the application will be able to access
    that resource. If the runtime environment does not record application
    capabilities in this manner, the runtime environment MUST list all
    permissions held by the runtime itself when installing any application
    using that runtime.</p>

 <a name="section-11"></a><h2>11. Compatibility Test Suite</h2>
 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS)
 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source
 Project, using the final shipping software on the device. Additionally, device
 implementers SHOULD use the reference implementation in the Android Open
 Source tree as much as possible, and MUST ensure compatibility in cases of
 ambiguity in CTS and for any reimplementations of parts of the reference
 source code.</p>
 <p>The CTS is designed to be run on an actual device. Like any software, the
 CTS may itself contain bugs.  The CTS will be versioned independently of this
 Compatibility Definition, and multiple revisions of the CTS may be released
 for Android 2.2. Device implementations MUST pass the latest CTS version
 available at the time the device software is completed.</p>

 <a name="section-12"></a><h2>12. Updatable Software</h2>
 <p>Device implementations MUST include a mechanism to replace the entirety of
 the system software. The mechanism need not perform "live" upgrades -- that
 is, a device restart MAY be required.</p>
 <p>Any method can be used, provided that it can replace the entirety of the
 software preinstalled on the device. For instance, any of the following
 approaches will satisfy this requirement:</p>
 <ul>
 <li>Over-the-air (OTA) downloads with offline update via reboot</li>
 <li>"Tethered" updates over USB from a host PC</li>
 <li>"Offline" updates via a reboot and update from a file on removable
 storage</li>
 </ul>
 <p>The update mechanism used MUST support updates without wiping user data.
 Note that the upstream Android software includes an update mechanism that
 satisfies this requirement.</p>
 <p>If an error is found in a device implementation after it has been released
 but within its reasonable product lifetime that is determined in consultation
 with the Android Compatibility Team to affect the compatibility of thid-party
 applications, the device implementer MUST correct the error via a software
 update available that can be applied per the mechanism just described.</p>

 <a name="section-13"></a><h2>13. Contact Us</h2>
 <p>You can contact the document authors at <a
 href="mailto:compatibility@android.com">compatibility@android.com</a> for
 clarifications and to bring up any issues that you think the document does not
 cover.</p>

 <div style="page-break-before: always;"></div>

 <a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2>
 <p>The Compatibility Test Suite includes cases that cover basic operation of
 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications
 protocol between devices, it cannot be fully tested by unit tests running on a
 single device. Consequently, device implementations MUST also pass the
 human-driven Bluetooth test procedure described below.</p>
 <p>The test procedure is based on the BluetoothChat sample app included in the
 Android open-source project tree. The procedure requires two devices:</p>
 <ul>
 <li>a candidate device implementation running the software build to be tested</li>
 <li>a separate device implementation already known to be compatible, and of a
     model from the device implementation being tested -- that is, a "known
     good" device implementation</li>
 </ul>
 <p>The test procedure below refers to these devices as the "candidate" and "known
 good" devices, respectively.</p>
 <h3>Setup and Installation</h3>
 <ol>
 <li>Build BluetoothChat.apk via 'make samples' from an Android source code tree.</li>
 <li>Install BluetoothChat.apk on the known-good device.</li>
 <li>Install BluetoothChat.apk on the candidate device.</li>
 </ol>
 <h3>Test Bluetooth Control by Apps</h3>
 <ol>
 <li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled.</li>
 <li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth.</li>
 </ol>
 <h3>Test Pairing and Communication</h3>
 <ol>
 <li>Launch the Bluetooth Chat app on both devices.</li>
 <li>Make the known-good device discoverable from within BluetoothChat (using the Menu).</li>
 <li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device.</li>
 <li>Send 10 or more messages from each device, and verify that the other device receives them correctly.</li>
 <li>Close the BluetoothChat app on both devices by pressing <b>Home</b>.</li>
 <li>Unpair each device from the other, using the device Settings app.</li>
 </ol>
 <h3>Test Pairing and Communication in the Reverse Direction</h3>
 <ol>
 <li>Launch the Bluetooth Chat app on both devices.</li>
 <li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li>
 <li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li>
 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li>
 <li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li>
 </ol>
 <h3>Test Re-Launches</h3>
 <ol>
 <li>Re-launch the Bluetooth Chat app on both devices.</li>
 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li>
 </ol>
 <p>Note: the above tests have some cases which end a test section by using
 Home, and some using Back. These tests are not redundant and are not optional:
 the objective is to verify that the Bluetooth API and stack works correctly
 both when Activities are explicitly terminated (via the user pressing Back,
 which calls finish()), and implicitly sent to background (via the user
 pressing Home.) Each test sequence MUST be performed as described.</p>
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