1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 4 <head> 5 <title>Android 2.2 Compatibility Definition</title> 6 <link rel="stylesheet" type="text/css" href="cdd.css"/> 7 </head> 8 <body> 9 <div><img src="header.jpg" alt="Android logo"/></div> 10 <h1>Android 2.2 Compatibility Definition</h1> 11 <!--<span style="color: red; font-weight: bold;"><h2>DRAFT</h2></span>--> 12 <p>Copyright © 2010, Google Inc. All rights reserved.<br/> 13 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 14 </p> 15 16 <h2> Table of Contents</h2> 17 <div style="margin-left: 2em;"> 18 <a href="#section-1">1. Introduction</a><br/> 19 <a href="#section-2">2. Resources</a><br/> 20 <a href="#section-3">3. Software</a><br/> 21 <div style="margin-left: 2em;"> 22 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 23 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 24 <div style="margin-left: 2em;"> 25 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 26 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/> 27 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 28 <div style="margin-left: 2em;"> 29 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 30 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 31 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 32 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 33 </div> 34 </div> 35 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 36 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 37 <div style="margin-left: 2em;"> 38 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 39 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 40 </div> 41 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 42 <a href="#section-3.6">3.6. API Namespaces</a><br/> 43 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 44 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 45 <div style="margin-left: 2em;"> 46 <a href="#section-3.8.1">3.8.1. Widgets</a><br/> 47 <a href="#section-3.8.2">3.8.2. Notifications</a><br/> 48 <a href="#section-3.8.3">3.8.3. Search</a><br/> 49 <a href="#section-3.8.4">3.8.4. Toasts</a><br/> 50 <a href="#section-3.8.5">3.8.5. Live Wallpapers</a><br/> 51 </div> 52 </div> 53 <a href="#section-4">4. Reference Software Compatibility</a><br/> 54 <a href="#section-5">5. Application Packaging Compatibility</a><br/> 55 <a href="#section-6">6. Multimedia Compatibility</a><br/> 56 <div style="margin-left: 2em;"> 57 <a href="#section-6.1">6.1. Media Codecs</a><br/> 58 <a href="#section-6.2">6.2. Audio Recording</a><br/> 59 <a href="#section-6.3">6.3. Audio Latency</a><br/> 60 </div> 61 <a href="#section-7">7. Developer Tool Compatibility</a><br/> 62 <a href="#section-8">8. Hardware Compatibility</a><br/> 63 <div style="margin-left: 2em;"> 64 <a href="#section-8.1">8.1. Display</a><br/> 65 <div style="margin-left: 2em;"> 66 <a href="#section-8.1.2">8.1.2. Non-Standard Display Configurations</a><br/> 67 <a href="#section-8.1.3">8.1.3. Display Metrics</a><br/> 68 <a href="#section-8.1.4">8.1.4. Declared Screen Support</a><br/> 69 </div> 70 <a href="#section-8.2">8.2. Keyboard</a><br/> 71 <a href="#section-8.3">8.3. Non-touch Navigation</a><br/> 72 <a href="#section-8.4">8.4. Screen Orientation</a><br/> 73 <a href="#section-8.5">8.5. Touchscreen input</a><br/> 74 <a href="#section-8.6">8.6. USB</a><br/> 75 <a href="#section-8.7">8.7. Navigation keys</a><br/> 76 <a href="#section-8.8">8.8. Wireless Data Networking</a><br/> 77 <a href="#section-8.9">8.9. Camera</a><br/> 78 <a href="#section-8.10">8.10. Accelerometer</a><br/> 79 <a href="#section-8.11">8.11. Compass</a><br/> 80 <a href="#section-8.12">8.12. GPS</a><br/> 81 <a href="#section-8.13">8.13. Telephony</a><br/> 82 <a href="#section-8.14">8.14. Memory and Storage</a><br/> 83 <a href="#section-8.15">8.15. Application Shared Storage</a><br/> 84 <a href="#section-8.16">8.16. Bluetooth</a><br/> 85 </div> 86 <a href="#section-9">9. Performance Compatibility</a><br/> 87 <a href="#section-10">10. Security Model Compatibility</a><br/> 88 <div style="margin-left: 2em;"> 89 <a href="#section-10.1">10.1. Permissions</a><br/> 90 <a href="#section-10.2">10.2. UID and Process Isolation</a><br/> 91 <a href="#section-10.3">10.3. Filesystem Permissions</a><br/> 92 <a href="#section-10.4">10.4. Alternate Execution Environments</a><br/> 93 </div> 94 <a href="#section-11">11. Compatibility Test Suite</a><br/> 95 <a href="#section-12">12. Updatable Software</a><br/> 96 <a href="#section-13">13. Contact Us</a><br/> 97 <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/> 98 </div> 99 100 <div style="page-break-before: always;"></div> 101 102 <a name="section-1"></a><h2>1. Introduction</h2> 103 <p>This document enumerates the requirements that must be met in order for 104 mobile phones to be compatible with Android 2.2.</p> 105 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 106 "should not", "recommended", "may" and "optional" is per the IETF standard 107 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 108 <p>As used in this document, a "device implementer" or "implementer" is a 109 person or organization developing a hardware/software solution running Android 110 2.2. A "device implementation" or "implementation" is the hardware/software 111 solution so developed.</p> 112 <p>To be considered compatible with Android 2.2, device implementations:</p> 113 <ul> 114 <li>MUST meet the requirements presented in this Compatibility Definition, 115 including any documents incorporated via reference.</li> 116 <li>MUST pass the most recent version of the Android Compatibility Test Suite 117 (CTS) available at the time of the device implementation's software is 118 completed. (The CTS is available as part of the Android Open Source Project [<a 119 href="#resources02">Resources, 2</a>].) The CTS tests many, but not all, of the 120 components outlined in this document.</li> 121 </ul> 122 <p>Where this definition or the CTS is silent, ambiguous, or incomplete, it is 123 the responsibility of the device implementer to ensure compatibility with 124 existing implementations. For this reason, the Android Open Source Project [<a 125 href="#resources03">Resources, 3</a>] is both the reference and preferred 126 implementation of Android. Device implementers are strongly encouraged to base 127 their implementations on the "upstream" source code available from the Android 128 Open Source Project. While some components can hypothetically be replaced with 129 alternate implementations this practice is strongly discouraged, as passing 130 the CTS tests will become substantially more difficult. It is the 131 implementer's responsibility to ensure full behavioral compatibility with the 132 standard Android implementation, including and beyond the Compatibility Test 133 Suite. Finally, note that certain component substitutions and modifications 134 are explicitly forbidden by this document.</p> 135 136 <a name="section-2"></a><h2>2. Resources</h2> 137 <ol> 138 <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> 139 <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> 140 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 141 <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> 142 <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> 143 <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> 144 <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> 145 <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> 146 <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> 147 <a name="resources10"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 148 <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> 149 <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> 150 <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> 151 <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> 152 <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> 153 <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> 154 <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> 155 <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> 156 <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> 157 <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> 158 <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> 159 <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> 160 <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> 161 <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> 162 <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> 163 <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> 164 <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> 165 <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> 166 <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> 167 <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> 168 </ol> 169 <p>Many of these resources are derived directly or indirectly from the Android 170 2.2 SDK, and will be functionally identical to the information in that SDK's 171 documentation. In any cases where this Compatibility Definition or the 172 Compatibility Test Suite disagrees with the SDK documentation, the SDK 173 documentation is considered authoritative. Any technical details provided in 174 the references included above are considered by inclusion to be part of this 175 Compatibility Definition.</p> 176 177 <a name="section-3"></a><h2>3. Software</h2> 178 <p>The Android platform includes a set of managed APIs, a set of native APIs, 179 and a body of so-called "soft" APIs such as the Intent system and 180 web-application APIs. This section details the hard and soft APIs that are 181 integral to compatibility, as well as certain other relevant technical and 182 user interface behaviors. Device implementations MUST comply with all the 183 requirements in this section.</p> 184 185 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 186 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 187 Android applications. The Android application programming interface (API) is 188 the set of Android platform interfaces exposed to applications running in the 189 managed VM environment. Device implementations MUST provide complete 190 implementations, including all documented behaviors, of any documented API 191 exposed by the Android 2.2 SDK [<a href="#resources04">Resources, 4</a>].</p> 192 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 193 or signatures, deviate from the documented behavior, or include no-ops, except 194 where specifically allowed by this Compatibility Definition.</p> 195 196 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 197 <p>In addition to the managed APIs from Section 3.1, Android also includes a 198 significant runtime-only "soft" API, in the form of such things such as 199 Intents, permissions, and similar aspects of Android applications that cannot 200 be enforced at application compile time. This section details the "soft" APIs 201 and system behaviors required for compatibility with Android 2.2. Device 202 implementations MUST meet all the requirements presented in this section.</p> 203 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 204 <p>Device implementers MUST support and enforce all permission constants as 205 documented by the Permission reference page [<a 206 href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional 207 requirements related to the Android security model.</p> 208 <a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4> 209 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 210 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 211 the current device. To provide consistent, meaningful values across device 212 implementations, the table below includes additional restrictions on the 213 formats of these values to which device implementations MUST conform.</p> 214 <table> 215 <tbody> 216 <tr> 217 <td><b>Parameter</b></td> 218 <td><b>Comments</b></td> 219 </tr> 220 <tr> 221 <td>android.os.Build.VERSION.RELEASE</td> 222 <td>The version of the currently-executing Android system, in human-readable 223 format. This field MUST have one of the string values defined in [<a 224 href="#resources07">Resources, 7</a>].</td> 225 </tr> 226 <tr> 227 <td>android.os.Build.VERSION.SDK</td> 228 <td>The version of the currently-executing Android system, in a format 229 accessible to third-party application code. For Android 2.2, this field MUST have 230 the integer value 8.</td> 231 </tr> 232 <tr> 233 <td>android.os.Build.VERSION.INCREMENTAL</td> 234 <td>A value chosen by the device implementer designating the specific build of 235 the currently-executing Android system, in human-readable format. This value 236 MUST NOT be re-used for different builds made available to end users. A typical use 237 of this field is to indicate which build number or source-control change 238 identifier was used to generate the build. There are no requirements on the 239 specific format of this field, except that it MUST NOT be null or the empty 240 string ("").</td> 241 </tr> 242 <tr> 243 <td>android.os.Build.BOARD</td> 244 <td>A value chosen by the device implementer identifying the specific internal 245 hardware used by the device, in human-readable format. A possible use of this 246 field is to indicate the specific revision of the board powering the device. 247 There are no requirements on the specific format of this field, except that it 248 MUST NOT be null or the empty string ("").</td> 249 </tr> 250 <tr> 251 <td>android.os.Build.BRAND</td> 252 <td>A value chosen by the device implementer identifying the name of the 253 company, organization, individual, etc. who produced the device, in 254 human-readable format. A possible use of this field is to indicate the OEM 255 and/or carrier who sold the device. There are no requirements on the specific 256 format of this field, except that it MUST NOT be null or the empty string 257 ("").</td> 258 </tr> 259 <tr> 260 <td>android.os.Build.DEVICE</td> 261 <td>A value chosen by the device implementer identifying the specific 262 configuration or revision of the body (sometimes called "industrial design") 263 of the device. There are no requirements on the specific format of this field, 264 except that it MUST NOT be null or the empty string ("").</td> 265 </tr> 266 <tr> 267 <td>android.os.Build.FINGERPRINT</td> 268 <td>A string that uniquely identifies this build. It SHOULD be reasonably 269 human-readable. It MUST follow this template: 270 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE)/$(BOARD):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 271 For example: 272 <br/><code>acme/mydevice/generic/generic:2.2/ERC77/3359:userdebug/test-keys</code><br/> 273 The fingerprint MUST NOT include whitespace characters. If other fields included in the 274 template above have whitespace characters, they MUST be replaced in the build 275 fingerprint with another character, such as the underscore ("_") character.</td> 276 </tr> 277 <tr> 278 <td>android.os.Build.HOST</td> 279 <td>A string that uniquely identifies the host the build was built on, in 280 human readable format. There are no requirements on the specific format of 281 this field, except that it MUST NOT be null or the empty string ("").</td> 282 </tr> 283 <tr> 284 <td>android.os.Build.ID</td> 285 <td>An identifier chosen by the device implementer to refer to a specific 286 release, in human readable format. This field can be the same as 287 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 288 meaningful for end users to distinguish between software builds. There are no 289 requirements on the specific format of this field, except that it MUST NOT be 290 null or the empty string ("").</td> 291 </tr> 292 <tr> 293 <td>android.os.Build.MODEL</td> 294 <td>A value chosen by the device implementer containing the name of the device 295 as known to the end user. This SHOULD be the same name under which the device 296 is marketed and sold to end users. There are no requirements on the specific 297 format of this field, except that it MUST NOT be null or the empty string 298 ("").</td> 299 </tr> 300 <tr> 301 <td>android.os.Build.PRODUCT</td> 302 <td>A value chosen by the device implementer containing the development name 303 or code name of the device. MUST be human-readable, but is not necessarily 304 intended for view by end users. There are no requirements on the specific 305 format of this field, except that it MUST NOT be null or the empty string 306 ("").</td> 307 </tr> 308 <tr> 309 <td>android.os.Build.TAGS</td> 310 <td>A comma-separated list of tags chosen by the device implementer that 311 further distinguish the build. For example, "unsigned,debug". This field MUST 312 NOT be null or the empty string (""), but a single tag (such as "release") is 313 fine.</td> 314 </tr> 315 <tr> 316 <td>android.os.Build.TIME</td> 317 <td>A value representing the timestamp of when the build occurred.</td> 318 </tr> 319 <tr> 320 <td>android.os.Build.TYPE</td> 321 <td>A value chosen by the device implementer specifying the runtime 322 configuration of the build. This field SHOULD have one of the values 323 corresponding to the three typical Android runtime configurations: "user", 324 "userdebug", or "eng".</td> 325 </tr> 326 <tr> 327 <td>android.os.Build.USER</td> 328 <td>A name or user ID of the user (or automated user) that generated the 329 build. There are no requirements on the specific format of this field, except 330 that it MUST NOT be null or the empty string ("").</td> 331 </tr> 332 </tbody> 333 </table> 334 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 335 <p>Android uses Intents to achieve loosely-coupled integration between 336 applications. This section describes requirements related to the Intent 337 patterns that MUST be honored by device implementations. By "honored", it is 338 meant that the device implementer MUST provide an Android Activity or Service 339 that specifies a matching Intent filter and binds to and implements correct 340 behavior for each specified Intent pattern.</p> 341 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 342 <p>The Android upstream project defines a number of core applications, such as 343 a phone dialer, calendar, contacts book, music player, and so on. Device 344 implementers MAY replace these applications with alternative versions.</p> 345 <p>However, any such alternative versions MUST honor the same Intent patterns 346 provided by the upstream project. For example, if a device contains an 347 alternative music player, it must still honor the Intent pattern issued by 348 third-party applications to pick a song.</p> 349 <p>The following applications are considered core Android system 350 applications:</p> 351 <ul> 352 <li>Desk Clock</li> 353 <li>Browser</li> 354 <li>Calendar</li> 355 <li>Calculator</li> 356 <li>Camera</li> 357 <li>Contacts</li> 358 <li>Email</li> 359 <li>Gallery</li> 360 <li>GlobalSearch</li> 361 <li>Launcher</li> 362 <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 363 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> 364 <li>Messaging (AKA "Mms")</li> 365 <li>Music</li> 366 <li>Phone</li> 367 <li>Settings</li> 368 <li>SoundRecorder</li> 369 </ul> 370 <p>The core Android system applications include various Activity, or Service 371 components that are considered "public". 372 That is, the attribute "android:exported" may be absent, or may have the value 373 "true".</p> 374 <p>For every Activity or Service defined 375 in one of the core Android system apps that is not marked as non-public via an 376 android:exported attribute with the value "false", device implementations MUST 377 include a compontent of the same type implementing the same Intent filter 378 patterns as the core Android system app.</p> 379 <p>In other words, a device implementation MAY replace core Android system 380 apps; however, if it does, the device implementation MUST support all Intent 381 patterns defined by each core Android system app being replaced.</p> 382 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 383 <p>As Android is an extensible platform, device implementers MUST allow each 384 Intent pattern referenced in Section 3.2.3.1 to be overridden by third-party 385 applications. The upstream Android open source project allows this by default; 386 device implementers MUST NOT attach special privileges to system applications' 387 use of these Intent patterns, or prevent third-party applications from binding 388 to and assuming control of these patterns. This prohibition specifically 389 includes but is not limited to disabling the "Chooser" user interface which 390 allows the user to select between multiple applications which all handle the 391 same Intent pattern.</p> 392 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 393 <p>Device implementers MUST NOT include any Android component that honors any 394 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 395 key string in the android.* namespace. Device implementers MUST NOT include 396 any Android components that honor any new Intent or Broadcast Intent patterns 397 using an ACTION, CATEGORY, or other key string in a package space belonging to 398 another organization. Device implementers MUST NOT alter or extend any of the 399 Intent patterns used by the core apps listed in Section 3.2.3.1.</p> 400 <p>This prohibition is analogous to that specified for Java language classes 401 in Section 3.6.</p> 402 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 403 <p>Third-party applications rely on the platform to broadcast certain Intents 404 to notify them of changes in the hardware or software environment. 405 Android-compatible devices MUST broadcast the public broadcast Intents in 406 response to appropriate system events. Broadcast Intents are described in the 407 SDK documentation.</p> 408 409 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 410 <p>Managed code running in Dalvik can call into native code provided in the 411 application .apk file as an ELF .so file compiled for the appropriate device 412 hardware architecture. Device implementations MUST include support for code 413 running in the managed environment to call into native code, using the 414 standard Java Native Interface (JNI) semantics. The following APIs MUST be 415 available to native code:</p> 416 <ul> 417 <li>libc (C library)</li> 418 <li>libm (math library)</li> 419 <li>JNI interface</li> 420 <li>libz (Zlib compression)</li> 421 <li>liblog (Android logging)</li> 422 <li>Minimal support for C++</li> 423 <li>Support for OpenGL, as described below</li> 424 </ul> 425 <p>Device implementations MUST support OpenGL ES 1.0. Devices that lack 426 hardware acceleration MUST implement OpenGL ES 1.0 using a software renderer. 427 Device implementations SHOULD implement as much of OpenGL ES 1.1 as the device 428 hardware supports. Device implementations SHOULD provide an implementation 429 for OpenGL ES 2.0, if the hardware is capable of reasonable performance on 430 those APIs.</p> 431 <p>These libraries MUST be source-compatible (i.e. header compatible) and 432 binary-compatible (for a given processor architecture) with the versions 433 provided in Bionic by the Android Open Source project. Since the Bionic 434 implementations are not fully compatible with other implementations such as 435 the GNU C library, device implementers SHOULD use the Android implementation. 436 If device implementers use a different implementation of these libraries, they 437 MUST ensure header, binary, and behavioral compatibility.</p> 438 <p>Device implementations MUST accurately report the native Application Binary 439 Interface (ABI) supported by the device, via the 440 <code>android.os.Build.CPU_ABI</code> API. The ABI MUST be one of the entries 441 documented in the latest version of the Android NDK, in the file 442 <code>docs/CPU-ARCH-ABIS.txt</code>. Note that additional releases of the 443 Android NDK may introduce support for additional ABIs.</p> 444 <p>Native code compatibility is challenging. For this reason, it should be 445 repeated that device implementers are VERY strongly encouraged to use the 446 upstream implementations of the libraries listed above to help ensure 447 compatibility.</p> 448 449 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 450 <p>Many developers and applications rely on the behavior of the 451 <code>android.webkit.WebView</code> class [<a 452 href="#resources08">Resources, 8</a>] 453 for their user interfaces, so the WebView implementation must be 454 compatible across Android implementations. Similarly, a full web experience is 455 central to the Android user experience. Device implementations MUST include a 456 version of <code>android.webkit.WebView</code> consistent with the upstream 457 Android software, and MUST include a modern HTML5-capable browser, as 458 described below.</p> 459 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 460 <p>The Android Open Source implementation uses the WebKit rendering engine to 461 implement the <code>android.webkit.WebView</code>. Because it is not feasible 462 to develop a comprehensive test suite for a web rendering system, device 463 implementers MUST use the specific upstream build of WebKit in the WebView 464 implementation. Specifically:</p> 465 <ul> 466 <li>Device implementations' <code>android.webkit.WebView</code> 467 implementations MUST be based on the 533.1 WebKit build from the upstream 468 Android Open Source tree for Android 2.2. This build includes a specific set 469 of functionality and security fixes for the WebView. Device implementers MAY 470 include customizations to the WebKit implementation; however, any such 471 customizations MUST NOT alter the behavior of the WebView, including rendering 472 behavior.</li> 473 <li>The user agent string reported by the WebView MUST be in this format:<br/> 474 <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> 475 <ul> 476 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 477 <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> 478 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 479 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 480 </ul></li> 481 </ul> 482 <p>The WebView configuration MUST include support for the HTML5 database, 483 application cache, and geolocation APIs [<a href="#resources09">Resources, 484 9</a>]. The WebView MUST include support for the HTML5 485 <code><video></code> tag. HTML5 APIs, like all JavaScript APIs, MUST be 486 disabled by default in a WebView, unless the developer explicitly enables them 487 via the usual Android APIs.</p> 488 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 489 <p>Device implementations MUST include a standalone Browser application for 490 general user web browsing. The standalone Browser MAY be based on an 491 browser technology other than WebKit. However, even if an alternate Browser 492 application is shipped, the <code>android.webkit.WebView</code> component 493 provided to third-party applications MUST be based on WebKit, as described in 494 Section 3.4.1.</p> 495 <p>Implementations MAY ship a custom user agent string in the standalone 496 Browser application.</p> 497 <p>The standalone Browser application (whether based on the upstream 498 WebKit Browser application or a third-party replacement) SHOULD include support 499 for as much of HTML5 [<a href="#resources09">Resources, 9</a>] as possible. 500 Minimally, device implementations MUST support HTML5 geolocation, application 501 cache, and database APIs and the <video> tag in standalone the Browser 502 application.</p> 503 504 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 505 <p>The behaviors of each of the API types (managed, soft, native, and web) 506 must be consistent with the preferred implementation of the upstream Android 507 open-source project [<a href="#resources03">Resources, 3</a>]. Some specific areas 508 of compatibility are:</p> 509 <ul> 510 <li>Devices MUST NOT change the behavior or meaning of a standard Intent</li> 511 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular type of system component (such as Service, Activity, ContentProvider, etc.)</li> 512 <li>Devices MUST NOT change the semantics of a particular permission</li> 513 </ul> 514 <p>The above list is not comprehensive, and the onus is on device implementers 515 to ensure behavioral compatibility. For this reason, device implementers 516 SHOULD use the source code available via the Android Open Source Project where 517 possible, rather than re-implement significant parts of the system.</p> 518 <p>The Compatibility Test Suite (CTS) tests significant portions of the 519 platform for behavioral compatibility, but not all. It is the responsibility 520 of the implementer to ensure behavioral compatibility with the Android Open 521 Source Project.</p> 522 523 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 524 <p>Android follows the package and class namespace conventions defined by the 525 Java programming language. To ensure compatibility with third-party 526 applications, device implementers MUST NOT make any prohibited modifications 527 (see below) to these package namespaces:</p> 528 <ul> 529 <li>java.*</li> 530 <li>javax.*</li> 531 <li>sun.*</li> 532 <li>android.*</li> 533 <li>com.android.*</li> 534 </ul> 535 <p>Prohibited modifications include:</p> 536 <ul> 537 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 538 Android platform by changing any method or class signatures, or by removing 539 classes or class fields.</li> 540 <li>Device implementers MAY modify the underlying implementation of the APIs, 541 but such modifications MUST NOT impact the stated behavior and Java-language 542 signature of any publicly exposed APIs.</li> 543 <li>Device implementers MUST NOT add any publicly exposed elements (such as 544 classes or interfaces, or fields or methods to existing classes or interfaces) 545 to the APIs above.</li> 546 </ul> 547 <p>A "publicly exposed element" is any construct which is not decorated with 548 the "@hide" marker in the upstream Android source code. In other words, device 549 implementers MUST NOT expose new APIs or alter existing APIs in the namespaces 550 noted above. Device implementers MAY make internal-only modifications, but 551 those modifications MUST NOT be advertised or otherwise exposed to 552 developers.</p> 553 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 554 namespace owned by or referring to another organization. For instance, device 555 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 556 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 557 namespaces.</p> 558 <p>If a device implementer proposes to improve one of the package namespaces 559 above (such as by adding useful new functionality to an existing API, or 560 adding a new API), the implementer SHOULD visit source.android.com and begin 561 the process for contributing changes and code, according to the information on 562 that site.</p> 563 <p>Note that the restrictions above correspond to standard conventions for 564 naming APIs in the Java programming language; this section simply aims to 565 reinforce those conventions and make them binding through inclusion in this 566 compatibility definition.</p> 567 568 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 569 <p>Device implementations MUST support the full Dalvik Executable (DEX) 570 bytecode specification and Dalvik Virtual Machine semantics [<a 571 href="#resources10">Resources, 10</a>].</p> 572 <p>Device implementations with screens classified as medium- or low-density 573 MUST configure Dalvik to allocate at least 16MB of memory to each application. 574 Device implementations with screens classified as high-density MUST configure 575 Dalvik to allocate at least 24MB of memory to each application. Note that 576 device implementations MAY allocate more memory than these figures.</p> 577 578 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 579 <p>The Android platform includes some developer APIs that allow developers to 580 hook into the system user interface. Device implementations MUST incorporate 581 these standard UI APIs into custom user interfaces they develop, as explained 582 below.</p> 583 <a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4> 584 <p>Android defines a component type and corresponding API and lifecycle that 585 allows applications to expose an "AppWidget" to the end user [<a 586 href="#resources11">Resources, 11</a>]. 587 The Android Open Source reference release includes a Launcher application that 588 includes user interface elements allowing the user to add, view, and remove 589 AppWidgets from the home screen.</p> 590 <p>Device implementers MAY substitute an alternative to the reference Launcher 591 (i.e. home screen). Alternative Launchers SHOULD include built-in support for 592 AppWidgets, and expose user interface elements to add, configure, view, and remove 593 AppWidgets directly within the Launcher. Alternative Launchers MAY omit these 594 user interface elements; however, if they are omitted, the device implementer 595 MUST provide a separate application accessible from the Launcher that allows 596 users to add, configure, view, and remove AppWidgets.</p> 597 <a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4> 598 <p>Android includes APIs that allow developers to notify users of notable 599 events [<a href="#resources12">Resources, 12</a>]. Device implementers MUST provide support for each 600 class of notification so defined; specifically: sounds, vibration, light and 601 status bar.</p> 602 <p>Additionally, the implementation MUST correctly render all resources 603 (icons, sound files, etc.) provided for in the APIs [<a 604 href="#resources13">Resources, 13</a>], or in the 605 Status Bar icon style guide [<a href="#resources14">Resources, 14</a>]. Device implementers MAY provide 606 an alternative user experience for notifications than that provided by the 607 reference Android Open Source implementation; however, such alternative 608 notification systems MUST support existing notification resources, as 609 above.</p> 610 <a name="section-3.8.3"></a><h4>3.8.3. Search</h4> 611 <p>Android includes APIs [<a href="#resources15">Resources, 15</a>] that allow developers to incorporate 612 search into their applications, and expose their application's data into the 613 global system search. Generally speaking, this functionality consists of a 614 single, system-wide user interface that allows users to enter queries, 615 displays suggestions as users type, and displays results. The Android APIs 616 allow developers to reuse this interface to provide search within their own 617 apps, and allow developers to supply results to the common global search user 618 interface.</p> 619 <p>Device implementations MUST include a single, shared, system-wide search 620 user interface capable of real-time suggestions in response to user input. 621 Device implementations MUST implement the APIs that allow developers to reuse 622 this user interface to provide search within their own applications. Device 623 implementations MUST implement the APIs that allow third-party applications to 624 add suggestions to the search box when it is run in global search mode. If no 625 third-party applications are installed that make use of this functionality, 626 the default behavior SHOULD be to display web search engine results and 627 suggestions.</p> 628 <p>Device implementations MAY ship alternate search user interfaces, but 629 SHOULD include a hard or soft dedicated search button, that can be used at any 630 time within any app to invoke the search framework, with the behavior provided 631 for in the API documentation.</p> 632 <a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4> 633 <p>Applications can use the "Toast" API (defined in [<a 634 href="#resources16">Resources, 16</a>]) to 635 display short non-modal strings to the end user, that disappear after a brief 636 period of time. Device implementations MUST display Toasts from applications 637 to end users in some high-visibility manner.</p> 638 <a name="section-3.8.5"></a><h4>3.8.5. Live Wallpapers</h4> 639 <p>Android defines a component type and corresponding API and lifecycle that 640 allows applications to expose one or more "Live Wallpapers" to the end user 641 [<a href="#resources17">Resources, 17</a>]. Live Wallpapers are animations, 642 patterns, or similar images with limited input capabilities that display as a 643 wallpaper, behind other applications.</p> 644 <p>Hardware is considered capable of reliably running live wallpapers if it 645 can run all live wallpapers, with no limitations on functionality, at a 646 reasonable framerate with no adverse affects on other applications. If 647 limitations in the hardware cause wallpapers and/or applications to crash, 648 malfunction, consume excessive CPU or battery power, or run at unacceptably 649 low frame rates, the hardware is considered incapable of running live 650 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 651 context to render their content. Live wallpaper will not run reliably on 652 hardware that does not support multiple OpenGL contexts because the live 653 wallpaper use of an OpenGL context may conflict with other applications that 654 also use an OpenGL context. </p> 655 <p>Device implementations capable of running live wallpapers reliably as 656 described above SHOULD implement live wallpapers. Device implementations 657 determined to not run live wallpapers reliably as described above MUST NOT 658 implement live wallpapers.</p> 659 660 <a name="section-4"></a><h2>4. Reference Software Compatibility</h2> 661 <p>Device implementers MUST test implementation compatibility using the 662 following open-source applications:</p> 663 <ul> 664 <li>Calculator (included in SDK)</li> 665 <li>Lunar Lander (included in SDK)</li> 666 <li>The "Apps for Android" applications [<a href="#resources18">Resources, 18</a>].</li> 667 <li>Replica Island (available in Android Market; only required for device 668 implementations that support with OpenGL ES 2.0)</li> 669 </ul> 670 <p>Each app above MUST launch and behave correctly on the implementation, for 671 the implementation to be considered compatible.</p> 672 <p>Additionally, device implementations MUST test each menu item (including all 673 sub-menus) of each of these smoke-test applications:</p> 674 <ul> 675 <li>ApiDemos (included in SDK)</li> 676 <li>ManualSmokeTests (included in CTS)</li> 677 </ul> 678 <p>Each test case in the applications above MUST run correctly on the device 679 implementation.</p> 680 681 <a name="section-5"></a><h2>5. Application Packaging Compatibility</h2> 682 <p>Device implementations MUST install and run Android ".apk" files as 683 generated by the "aapt" tool included in the official Android SDK [<a 684 href="#resources19">Resources, 19</a>].</p> 685 <p>Devices implementations MUST NOT extend either the .apk [<a 686 href="#resources20">Resources, 20</a>], Android Manifest [<a 687 href="#resources21">Resources, 21</a>], 688 or Dalvik bytecode [<a href="#resources10">Resources, 10</a>] formats in such 689 a way that would prevent those files from 690 installing and running correctly on other compatible devices. Device 691 implementers SHOULD use the reference upstream implementation of Dalvik, and 692 the reference implementation's package management system.</p> 693 694 <a name="section-6"></a><h2>6. Multimedia Compatibility</h2> 695 <p>Device implementations MUST fully implement all multimedia APIs. Device 696 implementations MUST include support for all multimedia codecs described 697 below, and SHOULD meet the sound processing guidelines described below.</p> 698 <a name="section-6.1"></a><h3>6.1. Media Codecs</h3> 699 <p>Device implementations MUST support the following multimedia codecs. All of 700 these codecs are provided as software implementations in the preferred Android 701 implementation from the Android Open Source Project.</p> 702 <p>Please note that neither Google nor the Open Handset Alliance make any 703 representation that these codecs are unencumbered by third-party patents. 704 Those intending to use this source code in hardware or software products are 705 advised that implementations of this code, including in open source software 706 or shareware, may require patent licenses from the relevant patent 707 holders.</p> 708 <table><tbody> 709 <tr> 710 <td rowspan="11"><b>Audio</b></td> 711 </tr> 712 <tr> 713 <td><b>Name</b></td> 714 <td><b>Encoder</b></td> 715 <td><b>Decoder</b></td> 716 <td><b>Details</b></td> 717 <td><b>File/Container Format</b></td> 718 </tr> 719 <tr> 720 <td>AAC LC/LTP</td> 721 <td> </td> 722 <td>X</td> 723 <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> 724 <td rowspan="3">3GPP (.3gp) and MPEG-4 (.mp4, .m4a). No support for raw AAC (.aac)</td> 725 </tr> 726 <tr> 727 <td>HE-AACv1 (AAC+)</td> 728 <td> </td> 729 <td>X</td> 730 </tr> 731 <tr> 732 <td>HE-AACv2 (enhanced AAC+)</td> 733 <td> </td> 734 <td>X</td> 735 </tr> 736 <tr> 737 <td>AMR-NB</td> 738 <td>X</td> 739 <td>X</td> 740 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 741 <td>3GPP (.3gp)</td> 742 </tr> 743 <tr> 744 <td>AMR-WB</td> 745 <td> </td> 746 <td>X</td> 747 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 748 <td>3GPP (.3gp)</td> 749 </tr> 750 <tr> 751 <td>MP3</td> 752 <td> </td> 753 <td>X</td> 754 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR)</td> 755 <td>MP3 (.mp3)</td> 756 </tr> 757 <tr> 758 <td>MIDI</td> 759 <td> </td> 760 <td>X</td> 761 <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> 762 <td>Type 0 and 1 (.mid, .xmf, .mxmf). Also RTTTL/RTX (.rtttl, .rtx), OTA (.ota), and iMelody (.imy)</td> 763 </tr> 764 <tr> 765 <td>Ogg Vorbis</td> 766 <td> </td> 767 <td>X</td> 768 <td> </td> 769 <td>Ogg (.ogg)</td> 770 </tr> 771 <tr> 772 <td>PCM</td> 773 <td> </td> 774 <td>X</td> 775 <td>8- and 16-bit linear PCM (rates up to limit of hardware)</td> 776 <td>WAVE (.wav)</td> 777 </tr> 778 <tr> 779 <td rowspan="5"><b>Image</b></td> 780 </tr> 781 <tr> 782 <td>JPEG</td> 783 <td>X</td> 784 <td>X</td> 785 <td>base+progressive</td> 786 <td> </td> 787 </tr> 788 <tr> 789 <td>GIF</td> 790 <td> </td> 791 <td>X</td> 792 <td> </td> 793 <td> </td> 794 </tr> 795 <tr> 796 <td>PNG</td> 797 <td>X</td> 798 <td>X</td> 799 <td> </td> 800 <td> </td> 801 </tr> 802 <tr> 803 <td>BMP</td> 804 <td> </td> 805 <td>X</td> 806 <td> </td> 807 <td> </td> 808 </tr> 809 <tr> 810 <td rowspan="4"><b>Video</b></td> 811 </tr> 812 <tr> 813 <td>H.263</td> 814 <td>X</td> 815 <td>X</td> 816 <td> </td> 817 <td>3GPP (.3gp) files</td> 818 </tr> 819 <tr> 820 <td>H.264</td> 821 <td> </td> 822 <td>X</td> 823 <td> </td> 824 <td>3GPP (.3gp) and MPEG-4 (.mp4) files</td> 825 </tr> 826 <tr> 827 <td>MPEG4 Simple Profile</td> 828 <td> </td> 829 <td>X</td> 830 <td> </td> 831 <td>3GPP (.3gp) file</td> 832 </tr> 833 </tbody> 834 </table> 835 <p>Note that the table above does not list specific bitrate requirements for 836 most video codecs. The reason for this is that in practice, current device 837 hardware does not necessarily support bitrates that map exactly to the 838 required bitrates specified by the relevant standards. Instead, device 839 implementations SHOULD support the highest bitrate practical on the hardware, 840 up to the limits defined by the specifications.</p> 841 842 <a name="section-6.2"></a><h3>6.2. Audio Recording</h3> 843 <p>When an application has used the <code>android.media.AudioRecord</code> API to 844 start recording an audio stream, device implementations SHOULD sample and 845 record audio with each of these behaviors:</p> 846 <ul> 847 <li>Noise reduction processing, if present, SHOULD be disabled.</li> 848 <li>Automatic gain control, if present, SHOULD be disabled.</li> 849 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 850 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 851 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 852 (SPL) source at 1000 Hz yields RMS of 5000 for 16-bit samples.</li> 853 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 854 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 855 <li>Total harmonic distortion SHOULD be less than 1% from 100 Hz to 4000 Hz at 856 90 dB SPL input level.</li> 857 </ul> 858 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD" 859 for Android 2.2, the Compatibility Definition for a future version is planned 860 to change these to "MUST". That is, these requirements are optional in Android 861 2.2 but <b>will be required</b> by a future version. Existing and new devices 862 that run Android 2.2 Android are <b>very strongly encouraged to meet 863 these requirements in Android 2.2</b>, or they will not be able to attain 864 Android compatibility when upgraded to the future version.</p> 865 866 <a name="section-6.3"></a><h3>6.3. Audio Latency</h3> 867 <p>Audio latency is broadly defined as the interval between when an 868 application requests an audio playback or record operation, and when the 869 device implementation actually begins the operation. Many classes of 870 applications rely on short latencies, to achieve real-time effects such sound 871 effects or VOIP communication. Device implementations SHOULD meet all audio 872 latency requirements outlined in this section.</p> 873 <p>For the purposes of this section:</p> 874 <ul> 875 <li>"cold output latency" is defined to be the interval between when an 876 application requests audio playback and when sound begins playing, when 877 the audio system has been idle and powered down prior to the request</li> 878 <li>"warm output latency" is defined to be the interval between when an 879 application requests audio playback and when sound begins playing, when 880 the audio system has been recently used but is currently idle (that is, 881 silent)</li> 882 <li>"continuous output latency" is defined to be the interval between when an 883 application issues a sample to be played and when the speaker physically 884 plays the corresponding sound, while the device is currently playing back 885 audio</li> 886 <li>"cold input latency" is defined to be the interval between when an 887 application requests audio recording and when the first sample is 888 delivered to the application via its callback, when the audio system and 889 microphone has been idle and powered down prior to the request</li> 890 <li>"continuous input latency" is defined to be when an ambient sound occurs 891 and when the sample corresponding to that sound is delivered to a 892 recording application via its callback, while the device is in recording 893 mode</li> 894 </ul> 895 <p>Using the above definitions, device implementations SHOULD exhibit each of 896 these properties:</p> 897 <ul> 898 <li>cold output latency of 100 milliseconds or less</li> 899 <li>warm output latency of 10 milliseconds or less</li> 900 <li>continuous output latency of 45 milliseconds or less</li> 901 <li>cold input latency of 100 milliseconds or less</li> 902 <li>continuous input latency of 50 milliseconds or less</li> 903 </ul> 904 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD" 905 for Android 2.2, the Compatibility Definition for a future version is planned 906 to change these to "MUST". That is, these requirements are optional in Android 907 2.2 but <b>will be required</b> by a future version. Existing and new devices 908 that run Android 2.2 Android are <b>very strongly encouraged to meet 909 these requirements in Android 2.2</b>, or they will not be able to attain 910 Android compatibility when upgraded to the future version.</p> 911 912 <a name="section-7"></a><h2>7. Developer Tool Compatibility</h2> 913 <p>Device implementations MUST support the Android Developer Tools provided in 914 the Android SDK. Specifically, Android-compatible devices MUST be compatible 915 with:</p> 916 <ul> 917 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources19">Resources, 19</a>]<br/> 918 Device implementations MUST support all <code>adb</code> functions as 919 documented in the Android SDK. The device-side <code>adb</code> daemon SHOULD 920 be inactive by default, but there MUST be a user-accessible mechanism to turn 921 on the Android Debug Bridge.</li> 922 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources19">Resources, 19</a>]<br/> 923 Device implementations MUST support all <code>ddms</code> features as documented in the 924 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 925 <code>ddms</code> SHOULD be inactive by default, 926 but MUST be supported whenever the user has activated the Android Debug 927 Bridge, as above.</li> 928 <li><b>Monkey</b> [<a href="#resources22">Resources, 22</a>]<br/> 929 Device implementations MUST include the Monkey framework, and make it 930 available for applications to use.</li> 931 </ul> 932 933 <a name="section-8"></a><h2>8. Hardware Compatibility</h2> 934 <p>Android is intended to support device implementers creating innovative form 935 factors and configurations. At the same time Android developers expect 936 certain hardware, sensors and APIs across all Android device. This section 937 lists the hardware features that all Android 2.2 compatible devices must 938 support.</p> 939 <p>If a device includes a particular hardware component that has a 940 corresponding API for third-party developers, the device implementation MUST 941 implement that API as defined in the Android SDK documentation. If an API in 942 the SDK interacts with a hardware component that is stated to be optional and the device 943 implementation does not possess that component:</p> 944 <ul> 945 <li>class definitions for the component's APIs MUST be present</li> 946 <li>the API's behaviors MUST be implemented as no-ops in some reasonable fashion</li> 947 <li>API methods MUST return null values where permitted by the SDK documentation</li> 948 <li>API methods MUST return no-op implementations of classes where null values are not permitted by the SDK documentation</li> 949 </ul> 950 <p>A typical example of a scenario where these requirements apply is the 951 telephony API: even on non-phone devices, these APIs must be implemented as 952 reasonable no-ops.</p> 953 <p>Device implementations MUST accurately report accurate hardware configuration 954 information via the <code>getSystemAvailableFeatures()</code> and 955 <code>hasSystemFeature(String)</code> methods on the 956 <code>android.content.pm.PackageManager</code> class. [<a 957 href="#resources23">Resources, 23</a>]</p> 958 959 <a name="section-8.1"></a><h3>8.1. Display</h3> 960 <p>Android 2.2 includes facilities that perform certain automatic scaling and 961 transformation operations under some circumstances, to ensure that third-party 962 applications run reasonably well on a variety of hardware configurations [<a 963 href="#resources24">Resources, 24</a>]. Devices MUST properly implement these 964 behaviors, as detailed in this section.</p> 965 <p>For Android 2.2, these are the most common display configurations:</p> 966 <table><tbody> 967 <tr> 968 <td>Screen Type</td> 969 <td>Width (Pixels)</td> 970 <td>Height (Pixels)</td> 971 <td>Diagonal Length Range (inches)</td> 972 <td>Screen Size Group</td> 973 <td>Screen Density Group</td> 974 </tr> 975 <tr> 976 <td>QVGA</td> 977 <td>240</td> 978 <td>320</td> 979 <td>2.6 - 3.0</td> 980 <td>Small</td> 981 <td>Low</td> 982 </tr> 983 <tr> 984 <td>WQVGA</td> 985 <td>240</td> 986 <td>400</td> 987 <td>3.2 - 3.5</td> 988 <td>Normal</td> 989 <td>Low</td> 990 </tr> 991 <tr> 992 <td>FWQVGA</td> 993 <td>240</td> 994 <td>432</td> 995 <td>3.5 - 3.8</td> 996 <td>Normal</td> 997 <td>Low</td> 998 </tr> 999 <tr> 1000 <td>HVGA</td> 1001 <td>320</td> 1002 <td>480</td> 1003 <td>3.0 - 3.5</td> 1004 <td>Normal</td> 1005 <td>Medium</td> 1006 </tr> 1007 <tr> 1008 <td>WVGA</td> 1009 <td>480</td> 1010 <td>800</td> 1011 <td>3.3 - 4.0</td> 1012 <td>Normal</td> 1013 <td>High</td> 1014 </tr> 1015 <tr> 1016 <td>FWVGA</td> 1017 <td>480</td> 1018 <td>854</td> 1019 <td>3.5 - 4.0</td> 1020 <td>Normal</td> 1021 <td>High</td> 1022 </tr> 1023 <tr> 1024 <td>WVGA </td> 1025 <td>480 </td> 1026 <td>800 </td> 1027 <td>4.8 - 5.5 </td> 1028 <td>Large </td> 1029 <td>Medium</td> 1030 </tr> 1031 <tr> 1032 <td>FWVGA</td> 1033 <td>480</td> 1034 <td>854</td> 1035 <td>5.0 - 5.8</td> 1036 <td>Large</td> 1037 <td>Medium</td> 1038 </tr> 1039 1040 </tbody></table> 1041 1042 <p>Device implementations corresponding to one of the standard configurations 1043 above MUST be configured to report the indicated screen size to applications 1044 via the <code>android.content.res.Configuration</code> [<a href="#resources25">Resources, 1045 24</a>] class.</p> 1046 <p>Some .apk packages have manifests that do not identify them as supporting a 1047 specific density range. When running such applications, the following 1048 constraints apply:</p> 1049 <ul> 1050 <li>Device implementations MUST interpret resources in a .apk that lack a 1051 density qualifier as defaulting to "medium" (known as "mdpi" in the SDK 1052 documentation.)</li> 1053 <li>When operating on a "low" density screen, device implementations MUST 1054 scale down medium/mdpi assets by a factor of 0.75.</li> 1055 <li>When operating on a "high" density screen, device implementations MUST 1056 scale up medium/mdpi assets by a factor of 1.5.</li> 1057 <li>Device implementations MUST NOT scale assets within a density range, and 1058 MUST scale assets by exactly these factors between density ranges.</li> 1059 </ul> 1060 1061 <a name="section-8.1.2"></a><h4>8.1.2. Non-Standard Display Configurations</h4> 1062 <p>Display configurations that do not match one of the standard configurations 1063 listed in Section 8.1.1 require additional consideration and work to be 1064 compatible. Device implementers MUST contact Android Compatibility Team as 1065 described in Section 13 to obtain classifications for screen-size bucket, 1066 density, and scaling factor. When provided with this information, device 1067 implementations MUST implement them as specified.</p> 1068 <p>Note that some display configurations (such as very large or very small 1069 screens, and some aspect ratios) are fundamentally incompatible with Android 1070 2.2; therefore device implementers are encouraged to contact Android 1071 Compatibility Team as early as possible in the development process.</p> 1072 1073 <a name="section-8.1.3"></a><h4>8.1.3. Display Metrics</h4> 1074 <p>Device implementations MUST report correct valuesfor all display metrics 1075 defined in <code>android.util.DisplayMetrics</code> [<a 1076 href="#resources26">Resources, 26</a>].</p> 1077 1078 <a name="section-8.1.4"></a><h4>8.1.4. Declared Screen Support</h4> 1079 <p>Applications may indicate which screen sizes they support via the 1080 <code><supports-screens></code> attribute in the AndroidManifest.xml 1081 file. Device implementations MUST correctly honor applications' stated support 1082 for small, medium, and large screens, as described in the Android 1083 SDK documentation.</p> 1084 1085 <a name="section-8.2"></a><h3>8.2. Keyboard</h3> 1086 <p>Device implementations:</p> 1087 <ul> 1088 <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> 1089 <li>MUST provide at least one soft keyboard implementation (regardless of whether a hard keyboard is present)</li> 1090 <li>MAY include additional soft keyboard implementations</li> 1091 <li>MAY include a hardware keyboard</li> 1092 <li>MUST NOT include a hardware keyboard that does not match one of the 1093 formats specified in <code>android.content.res.Configuration.keyboard</code> 1094 [<a href="#resources25">Resources, 25</a>] (that is, QWERTY, or 12-key)</li> 1095 </ul> 1096 <a name="section-8.3"></a><h3>8.3. Non-touch Navigation</h3> 1097 <p>Device implementations:</p> 1098 <ul> 1099 <li>MAY omit a non-touch navigation options (that is, may omit a trackball, d-pad, or wheel)</li> 1100 <li>MUST report the correct value for 1101 <code>android.content.res.Configuration.navigation</code> [<a href="#resources25">Resources, 25</a>]</li> 1102 </ul> 1103 <a name="section-8.4"></a><h3>8.4. Screen Orientation</h3> 1104 <p>Compatible devices MUST support dynamic orientation by applications to 1105 either portrait or landscape screen orientation. That is, the device must 1106 respect the application's request for a specific screen orientation. Device 1107 implementations MAY select either portrait or landscape orientation as the 1108 default.</p> 1109 <p>Devices MUST report the correct value for the device's current orientation, 1110 whenever queried via the android.content.res.Configuration.orientation, 1111 android.view.Display.getOrientation(), or other APIs.</p> 1112 1113 <a name="section-8.5"></a><h3>8.5. Touchscreen input</h3> 1114 <p>Device implementations:</p> 1115 <ul> 1116 <li>MUST have a touchscreen</li> 1117 <li>MAY have either capacative or resistive touchscreen</li> 1118 <li>MUST report the value of <code>android.content.res.Configuration</code> 1119 [<a href="#resources25">Resources, 25</a>] 1120 reflecting corresponding to the type of the specific touchscreen on the 1121 device</li> 1122 <li>SHOULD support fully independently tracked pointers, if the touchscreen supports multiple pointers</li> 1123 </ul> 1124 1125 <a name="section-8.6"></a><h3>8.6. USB</h3> 1126 <p>Device implementations:</p> 1127 <ul> 1128 <li>MUST implement a USB client, connectable to a USB host with a standard 1129 USB-A port</li> 1130 <li>MUST implement the Android Debug Bridge over USB (as described in Section 1131 7)</li> 1132 <li>MUST implement the USB mass storage specification, to allow a host 1133 connected to the device to access the contents of the /sdcard volume </li> 1134 <li>SHOULD use the micro USB form factor on the device side</li> 1135 <li>MAY include a non-standard port on the device side, but if so MUST ship 1136 with a cable capable of connecting the custom pinout to standard USB-A 1137 port</li> 1138 <li>SHOULD implement support for the USB Mass Storage specification (so that 1139 either removable or fixed storage on the device can be accessed from a host 1140 PC)</li> 1141 </ul> 1142 1143 <a name="section-8.7"></a><h3>8.7. Navigation keys</h3> 1144 <p>The Home, Menu and Back functions are essential to the Android navigation 1145 paradigm. Device implementations MUST make these functions available to the 1146 user at all times, regardless of application state. These functions SHOULD be 1147 implemented via dedicated buttons. They MAY be implemented using software, 1148 gestures, touch panel, etc., but if so they MUST be always accessible and not 1149 obscure or interfere with the available application display area.</p> 1150 <p>Device implementers SHOULD also provide a dedicated search key. Device 1151 implementers MAY also provide send and end keys for phone calls.</p> 1152 1153 <a name="section-8.8"></a><h3>8.8. Wireless Data Networking</h3> 1154 <p>Device implementations MUST include support for wireless high-speed data 1155 networking. Specifically, device implementations MUST include support for at 1156 least one wireless data standard capable of 200Kbit/sec or greater. Examples of 1157 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, etc.</p> 1158 <p>If a device implementation includes a particular modality for which the 1159 Android SDK includes an API (that is, WiFi, GSM, or CDMA), the implementation 1160 MUST support the API.</p> 1161 <p>Devices MAY implement more than one form of wireless data connectivity. 1162 Devices MAY implement wired data connectivity (such as Ethernet), but MUST 1163 nonetheless include at least one form of wireless connectivity, as above.</p> 1164 1165 <a name="section-8.9"></a><h3>8.9. Camera</h3> 1166 <p>Device implementations MUST include a rear-facing camera. The included 1167 rear-facing camera:</p> 1168 <ul> 1169 <li>MUST have a resolution of at least 2 megapixels</li> 1170 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 1171 in the camera driver (transparent to application software)</li> 1172 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 1173 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 1174 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 1175 registered on a Camera preview surface, unless the application has explicitly 1176 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 1177 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 1178 object. Note that this constraint does not apply to the device's built-in 1179 system camera application, but only to third-party applications using 1180 <code>Camera.PreviewCallback</code>.</li> 1181 </ul> 1182 <p>Device implementations MUST implement the following behaviors for the 1183 camera-related APIs:</p> 1184 <ol> 1185 <li>If an application has never called 1186 android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 1187 use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 1188 application callbacks.</li> 1189 <li>If an application registers an android.hardware.Camera.PreviewCallback 1190 instance and the system calls the onPreviewFrame() method when the preview 1191 format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() 1192 must further be in the NV21 encoding format. (This is the format used natively 1193 by the 7k hardware family.) That is, NV21 MUST be the default.</li> 1194 </ol> 1195 <p>Device implementations MUST implement the full Camera API included in the 1196 Android 2.2 SDK documentation [<a href="#resources27">Resources, 27</a>]), 1197 regardless of whether the device includes hardware autofocus or other 1198 capabilities. For instance, cameras that lack autofocus MUST still call any 1199 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 1200 this has no relevance to a non-autofocus camera.)</p> 1201 <p>Device implementations MUST recognize and honor each parameter name defined 1202 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 1203 underlying hardware supports the feature. If the device hardware does not 1204 support a feature, the API must behave as documented. Conversely, Device 1205 implementations MUST NOT honor or recognize string constants passed 1206 to the <code>android.hardware.Camera.setParameters()</code> method other than 1207 those documented as constants on the 1208 <code>android.hardware.Camera.Parameters</code>. That is, 1209 device implementations MUST support all standard Camera parameters if the 1210 hardware allows, and MUST NOT support custom Camera parameter types.</p> 1211 <p>Device implementations MAY include a front-facing camera. However, if 1212 a device implementation includes a front-facing camera, the camera API as 1213 implemented on the device MUST NOT use the front-facing camera by default. 1214 That is, the camera API in Android 2.2 is for rear-facing cameras only, and 1215 device implementations MUST NOT reuse or overload the API to act on a 1216 front-facing camera, if one is present. Note that any custom APIs added by 1217 device implementers to support front-facing cameras MUST abide by sections 3.5 1218 and 3.6; for instance, if a custom <code>android.hardware.Camera</code> or 1219 <code>Camera.Parameters</code> subclass is provided to support front-facing 1220 cameras, it MUST NOT be located in an existing namespace, as described by 1221 sections 3.5 and 3.6. Note that the inclusion of a front-facing camera does 1222 not meet the requirement that devices include a rear-facing camera.</p> 1223 1224 <a name="section-8.10"></a><h3>8.10. Accelerometer</h3> 1225 <p>Device implementations MUST include a 3-axis accelerometer and MUST be able 1226 to deliver events at 50 Hz or greater. The coordinate system used by the 1227 accelerometer MUST comply with the Android sensor coordinate system as detailed 1228 in the Android APIs (see [<a href="#resources28">Resources, 28</a>]).</p> 1229 1230 <a name="section-8.11"></a><h3>8.11. Compass</h3> 1231 <p>Device implementations MUST include a 3-axis compass and MUST be able to 1232 deliver events 10 Hz or greater. The coordinate system used by the compass 1233 MUST comply with the Android sensor coordinate system as defined in the Android 1234 API (see [<a href="#resources28">Resources, 28</a>]).</p> 1235 1236 <a name="section-8.12"></a><h3>8.12. GPS</h3> 1237 <p>Device implementations MUST include a GPS receiver, and SHOULD include 1238 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1239 1240 <a name="section-8.13"></a><h3>8.13. Telephony</h3> 1241 <p>Android 2.2 MAY be used on devices that do not include telephony hardware. 1242 That is, Android 2.2 is compatible with devices that are not phones. 1243 However, if a device implementation does include GSM or CDMA telephony, it 1244 MUST implement the full support for the API for that technology. Device 1245 implementations that do not include telephony hardware MUST implement the full 1246 APIs as no-ops.</p> 1247 <p>See also Section 8.8, Wireless Data Networking.</p> 1248 1249 <a name="section-8.14"></a><h3>8.14. Memory and Storage</h3> 1250 <p>Device implementations MUST have at least 92MB of memory available to the 1251 kernel and userspace. The 92MB MUST be in addition to any memory dedicated to 1252 hardware components such as radio, memory, and so on that is not under the 1253 kernel's control.</p> 1254 <p>Device implementations MUST have at least 150MB of non-volatile storage 1255 available for user data. That is, the <code>/data</code> partition MUST be at 1256 least 150MB.</p> 1257 <p>Beyond the requirements above, device implementations SHOULD have at least 1258 128MB of memory available to kernel and userspace, in addition to any memory 1259 dedicated to hardware components that is not under the kernel's control. 1260 Device implementations SHOULD have at least 1GB of non-volatile storage 1261 available for user data. Note that these higher requirements are planned to 1262 become hard minimums in a future version of Android. Device implementations are 1263 strongly encouraged to meet these requirements now, or else they may not be 1264 eligible for compatibility for a future version of Android.</p> 1265 1266 <a name="section-8.15"></a><h3>8.15. Application Shared Storage</h3> 1267 <p>Device implementations MUST offer shared storage for applications. The 1268 shared storage provided MUST be at least 2GB in size.</p> 1269 <p>Device implementations MUST be configured with shared storage mounted by 1270 default, "out of the box". If the shared storage is not mounted on the Linux 1271 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 1272 from <code>/sdcard</code> to the actual mount point.</p> 1273 <p>Device implementations MUST enforce as documented the 1274 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 1275 shared storage. Shared storage MUST otherwise be writable by any application 1276 that obtains that permission.</p> 1277 <p>Device implementations MAY have hardware for user-accessible removable 1278 storage, such as a Secure Digital card. Alternatively, device implementations 1279 MAY allocate internal (non-removable) storage as shared storage for apps.</p> 1280 <p>Regardless of the form of shared storage used, the shared storage MUST 1281 implement USB mass storage, as described in Section 8.6. As shipped out of the 1282 box, the shared storage MUST be mounted with the FAT filesystem.</p> 1283 <p>It is illustrative to consider two common examples. If a device 1284 implementation includes an SD card slot to satisfy the shared storage 1285 requirement, a FAT-formatted SD card 2GB in size or larger MUST be included 1286 with the device as sold to users, and MUST be mounted by default. 1287 Alternatively, if a device implementation uses internal fixed storage to 1288 satisfy this requirement, that storage MUST be 2GB in size or larger, 1289 formatted as FAT, and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 1290 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 1291 <p>Device implementations that include multiple shared storage paths (such as 1292 both an SD card slot and shared internal storage) SHOULD modify the core 1293 applications such as the media scanner and ContentProvider to transparently 1294 support files placed in both locations.</p> 1295 1296 <a name="section-8.16"></a><h3>8.16. Bluetooth</h3> 1297 <p>Device implementations MUST include a Bluetooth transceiver. Device 1298 implementations MUST enable the RFCOMM-based Bluetooth API as described in the 1299 SDK documentation [<a href="#resources30">Resources, 30</a>]. Device 1300 implementations SHOULD implement relevant Bluetooth profiles, such as A2DP, 1301 AVRCP, OBEX, etc. as appropriate for the device.</p> 1302 <p>The Compatibility Test Suite includes cases that cover basic operation of 1303 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 1304 protocol between devices, it cannot be fully tested by unit tests running on a 1305 single device. Consequently, device implementations MUST also pass the 1306 human-driven Bluetooth test procedure described in Appendix A.</p> 1307 1308 <a name="section-9"></a><h2>9. Performance Compatibility</h2> 1309 <p>One of the goals of the Android Compatibility Program is to enable 1310 consistent application experience to consumers. Compatible implementations 1311 must ensure not only that applications simply run correctly on the device, but 1312 that they do so with reasonable performance and overall good user experience. 1313 Device implementations MUST meet the key performance metrics of an Android 2.2 1314 compatible device defined in the table below:</p> 1315 <table><tbody><tr> 1316 <td><b>Metric</b></td> 1317 <td><b>Performance Threshold</b></td> 1318 <td><b>Comments</b></td> 1319 </tr> 1320 <tr> 1321 <td>Application Launch Time</td> 1322 <td>The following applications should launch within the specified time.<ul> 1323 <li>Browser: less than 1300ms</li> 1324 <li>MMS/SMS: less than 700ms</li> 1325 <li>AlarmClock: less than 650ms</li> 1326 </ul></td> 1327 <td>The launch time is measured as the total time to 1328 complete loading the default activity for the application, including the time 1329 it takes to start the Linux process, load the Android package into the Dalvik 1330 VM, and call onCreate.</td> 1331 </tr> 1332 <tr> 1333 <td>Simultaneous Applications</td> 1334 <td>When multiple applications have been launched, re-launching an 1335 already-running application after it has been launched must take less than the 1336 original launch time.</td> 1337 <td> </td> 1338 </tr> 1339 </tbody> 1340 </table> 1341 1342 <a name="section-10"></a><h2>10. Security Model Compatibility</h2> 1343 <p>Device implementations MUST implement a security model consistent with the 1344 Android platform security model as defined in Security and Permissions 1345 reference document in the APIs [<a href="#resources29">Resources, 29</a>] in the 1346 Android developer documentation. Device implementations MUST support 1347 installation of self-signed applications without requiring any additional 1348 permissions/certificates from any third parties/authorities. Specifically, 1349 compatible devices MUST support the security mechanisms described in the 1350 follow sub-sections.</p> 1351 <a name="section-10.1"></a><h3>10.1. Permissions</h3> 1352 <p>Device implementations MUST support the Android permissions model as 1353 defined in the Android developer documentation [<a 1354 href="#resources29">Resources, 29</a>]. Specifically, 1355 implementations MUST enforce each permission defined as described in the SDK 1356 documentation; no permissions may be omitted, altered, or ignored. 1357 Implementations MAY add additional permissions, provided the new permission ID 1358 strings are not in the android.* namespace.</p> 1359 <a name="section-10.2"></a><h3>10.2. UID and Process Isolation</h3> 1360 <p>Device implementations MUST support the Android application sandbox model, 1361 in which each application runs as a unique Unix-style UID and in a separate 1362 process. Device implementations MUST support running multiple applications as 1363 the same Linux user ID, provided that the applications are properly signed and 1364 constructed, as defined in the Security and Permissions reference [<a 1365 href="#resources29">Resources, 29</a>].</p> 1366 <a name="section-10.3"></a><h3>10.3. Filesystem Permissions</h3> 1367 <p>Device implementations MUST support the Android file access permissions 1368 model as defined in as defined in the Security and Permissions reference [<a 1369 href="#resources29">Resources, 29</a>].</p> 1370 <a name="section-10.4"></a><h3>10.4. Alternate Execution Environments</h3> 1371 <p>Device implementations MAY include runtime environments that execute 1372 applications using some other software or technology than the Dalvik virtual 1373 machine or native code. However, such alternate execution environments MUST 1374 NOT compromise the Android security model or the security of installed Android 1375 applications, as described in this section.</p> 1376 <p>Alternate runtimes MUST themselves be Android applications, and abide by 1377 the standard Android security model, as described elsewhere in Section 10.</p> 1378 <p>Alternate runtimes MUST NOT be granted access to resources protected by 1379 permissions not requested in the runtime's AndroidManifest.xml file via the 1380 <code><uses-permission></code> mechanism.</p> 1381 <p>Alternate runtimes MUST NOT permit applications to make use of features 1382 protected by Android permissions restricted to system applications.</p> 1383 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 1384 <ul> 1385 <li>Alternate runtimes SHOULD install apps via the PackageManager into 1386 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 1387 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 1388 applications using the alternate runtime.</li> 1389 <li>Alternate runtimes and installed applications using an alternate runtime 1390 MUST NOT reuse the sandbox of any other app installed on the device, except 1391 through the standard Android mechanisms of shared user ID and signing 1392 certificate</li> 1393 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 1394 the sandboxes corresponding to other Android applications.</li> 1395 </ul> 1396 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 1397 applications any privileges of the superuser (root), or of any other user ID.</p> 1398 <p>The .apk files of alternate runtimes MAY be included in the system image of 1399 a device implementation, but MUST be signed with a key distinct 1400 from the key used to sign other applications included with the device 1401 implementation.</p> 1402 <p>When installing applications, alternate runtimes MUST obtain user consent 1403 for the Android permissions used by the application. That is, if an 1404 application needs to make use of a device resource for which there is a 1405 corresponding Android permission (such as Camera, GPS, etc.), the alternate 1406 runtime MUST inform the user that the application will be able to access 1407 that resource. If the runtime environment does not record application 1408 capabilities in this manner, the runtime environment MUST list all 1409 permissions held by the runtime itself when installing any application 1410 using that runtime.</p> 1411 1412 <a name="section-11"></a><h2>11. Compatibility Test Suite</h2> 1413 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 1414 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 1415 Project, using the final shipping software on the device. Additionally, device 1416 implementers SHOULD use the reference implementation in the Android Open 1417 Source tree as much as possible, and MUST ensure compatibility in cases of 1418 ambiguity in CTS and for any reimplementations of parts of the reference 1419 source code.</p> 1420 <p>The CTS is designed to be run on an actual device. Like any software, the 1421 CTS may itself contain bugs. The CTS will be versioned independently of this 1422 Compatibility Definition, and multiple revisions of the CTS may be released 1423 for Android 2.2. Device implementations MUST pass the latest CTS version 1424 available at the time the device software is completed.</p> 1425 1426 <a name="section-12"></a><h2>12. Updatable Software</h2> 1427 <p>Device implementations MUST include a mechanism to replace the entirety of 1428 the system software. The mechanism need not perform "live" upgrades -- that 1429 is, a device restart MAY be required.</p> 1430 <p>Any method can be used, provided that it can replace the entirety of the 1431 software preinstalled on the device. For instance, any of the following 1432 approaches will satisfy this requirement:</p> 1433 <ul> 1434 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 1435 <li>"Tethered" updates over USB from a host PC</li> 1436 <li>"Offline" updates via a reboot and update from a file on removable 1437 storage</li> 1438 </ul> 1439 <p>The update mechanism used MUST support updates without wiping user data. 1440 Note that the upstream Android software includes an update mechanism that 1441 satisfies this requirement.</p> 1442 <p>If an error is found in a device implementation after it has been released 1443 but within its reasonable product lifetime that is determined in consultation 1444 with the Android Compatibility Team to affect the compatibility of thid-party 1445 applications, the device implementer MUST correct the error via a software 1446 update available that can be applied per the mechanism just described.</p> 1447 1448 <a name="section-13"></a><h2>13. Contact Us</h2> 1449 <p>You can contact the document authors at <a 1450 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 1451 clarifications and to bring up any issues that you think the document does not 1452 cover.</p> 1453 1454 <div style="page-break-before: always;"></div> 1455 1456 <a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2> 1457 <p>The Compatibility Test Suite includes cases that cover basic operation of 1458 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 1459 protocol between devices, it cannot be fully tested by unit tests running on a 1460 single device. Consequently, device implementations MUST also pass the 1461 human-driven Bluetooth test procedure described below.</p> 1462 <p>The test procedure is based on the BluetoothChat sample app included in the 1463 Android open-source project tree. The procedure requires two devices:</p> 1464 <ul> 1465 <li>a candidate device implementation running the software build to be tested</li> 1466 <li>a separate device implementation already known to be compatible, and of a 1467 model from the device implementation being tested -- that is, a "known 1468 good" device implementation</li> 1469 </ul> 1470 <p>The test procedure below refers to these devices as the "candidate" and "known 1471 good" devices, respectively.</p> 1472 <h3>Setup and Installation</h3> 1473 <ol> 1474 <li>Build BluetoothChat.apk via 'make samples' from an Android source code tree.</li> 1475 <li>Install BluetoothChat.apk on the known-good device.</li> 1476 <li>Install BluetoothChat.apk on the candidate device.</li> 1477 </ol> 1478 <h3>Test Bluetooth Control by Apps</h3> 1479 <ol> 1480 <li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled.</li> 1481 <li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth.</li> 1482 </ol> 1483 <h3>Test Pairing and Communication</h3> 1484 <ol> 1485 <li>Launch the Bluetooth Chat app on both devices.</li> 1486 <li>Make the known-good device discoverable from within BluetoothChat (using the Menu).</li> 1487 <li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device.</li> 1488 <li>Send 10 or more messages from each device, and verify that the other device receives them correctly.</li> 1489 <li>Close the BluetoothChat app on both devices by pressing <b>Home</b>.</li> 1490 <li>Unpair each device from the other, using the device Settings app.</li> 1491 </ol> 1492 <h3>Test Pairing and Communication in the Reverse Direction</h3> 1493 <ol> 1494 <li>Launch the Bluetooth Chat app on both devices.</li> 1495 <li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li> 1496 <li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li> 1497 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 1498 <li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li> 1499 </ol> 1500 <h3>Test Re-Launches</h3> 1501 <ol> 1502 <li>Re-launch the Bluetooth Chat app on both devices.</li> 1503 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 1504 </ol> 1505 <p>Note: the above tests have some cases which end a test section by using 1506 Home, and some using Back. These tests are not redundant and are not optional: 1507 the objective is to verify that the Bluetooth API and stack works correctly 1508 both when Activities are explicitly terminated (via the user pressing Back, 1509 which calls finish()), and implicitly sent to background (via the user 1510 pressing Home.) Each test sequence MUST be performed as described.</p> 1511 <div id="footerContent"> 1512 <pdf:pagenumber/> 1513 </div> 1514 </body> 1515 </html> 1516
