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 2.3 Compatibility Definition</title> 6 <link rel="stylesheet" type="text/css" href="cdd.css"/> 7 </head> 8 <body> 9 <h1>Android 2.3 Compatibility Definition</h1> 10 <!-- <span style="color: red; font-weight: bold;"><h2>DRAFT</h2></span> --> 11 <p>Copyright © 2010, Google Inc. All rights reserved.<br/> 12 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 13 </p> 14 15 <h2> Table of Contents</h2> 16 <div style="margin-left: 2em;"> 17 <a href="#section-1">1. Introduction</a><br/> 18 <a href="#section-2">2. Resources</a><br/> 19 <a href="#section-3">3. Software</a><br/> 20 <div style="margin-left: 2em;"> 21 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 22 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 23 <div style="margin-left: 2em;"> 24 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 25 <a href="#section-3.2.3">3.2.2. Build Parameters</a><br/> 26 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 27 <div style="margin-left: 2em;"> 28 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 29 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 30 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 31 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 32 </div> 33 </div> 34 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 35 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 36 <div style="margin-left: 2em;"> 37 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 38 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 39 </div> 40 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 41 <a href="#section-3.6">3.6. API Namespaces</a><br/> 42 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 43 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 44 <div style="margin-left: 2em;"> 45 <a href="#section-3.8.1">3.8.1. Widgets</a><br/> 46 <a href="#section-3.8.2">3.8.2. Notifications</a><br/> 47 <a href="#section-3.8.3">3.8.3. Search</a><br/> 48 <a href="#section-3.8.4">3.8.4. Toasts</a><br/> 49 <a href="#section-3.8.5">3.8.5. Live Wallpapers</a><br/> 50 </div> 51 </div> 52 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 53 <a href="#section-5">5. Multimedia Compatibility</a><br/> 54 <div style="margin-left: 2em;"> 55 <a href="#section-5.1">5.1. Media Codecs</a><br/> 56 <a href="#section-5.1.1">5.1.1. Media Decoders</a><br/> 57 <a href="#section-5.1.2">5.1.2. Media Encoders</a><br/> 58 <a href="#section-5.2">5.2. Audio Recording</a><br/> 59 <a href="#section-5.3">5.3. Audio Latency</a><br/> 60 </div> 61 <a href="#section-6">6. Developer Tool Compatibility</a><br/> 62 <a href="#section-7">7. Hardware Compatibility</a><br/> 63 <div style="margin-left: 2em;"> 64 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 65 <div style="margin-left: 2em;"> 66 <a href="#section-7.1.1">7.1.1. Screen Configurations</a><br/> 67 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 68 <a href="#section-7.1.3">7.1.3. Declared Screen Support</a><br/> 69 <a href="#section-7.1.4">7.1.4. Screen Orientation</a><br/> 70 <a href="#section-7.1.5">7.1.5. 3D Graphics Accleration</a><br/> 71 </div> 72 <a href="#section-7.2">7.2. Input Devices</a><br/> 73 <div style="margin-left: 2em;"> 74 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 75 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 76 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 77 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 78 </div> 79 <a href="#section-7.3">7.3. Sensors</a><br/> 80 <div style="margin-left: 2em;"> 81 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 82 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 83 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 84 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 85 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 86 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 87 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 88 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 89 </div> 90 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 91 <div style="margin-left: 2em;"> 92 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 93 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/> 94 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 95 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 96 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 97 </div> 98 <a href="#section-7.5">7.5. Cameras</a><br/> 99 <div style="margin-left: 2em;"> 100 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 101 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 102 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 103 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 104 </div> 105 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 106 <div style="margin-left: 2em;"> 107 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 108 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/> 109 </div> 110 <a href="#section-7.7">7.7. USB</a><br/> 111 </div> 112 <a href="#section-8">8. Performance Compatibility</a><br/> 113 <a href="#section-9">9. Security Model Compatibility</a><br/> 114 <div style="margin-left: 2em;"> 115 <a href="#section-9.1">9.1. Permissions</a><br/> 116 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 117 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 118 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 119 </div> 120 <a href="#section-10">10. Software Compatibility Testing</a><br/> 121 <div style="margin-left: 2em;"> 122 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 123 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 124 <a href="#section-10.3">10.3. Reference Applications</a><br/> 125 </div> 126 <a href="#section-11">11. Updatable Software</a><br/> 127 <a href="#section-12">12. Contact Us</a><br/> 128 <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/> 129 </div> 130 131 <div style="page-break-before: always;"></div> 132 133 <a name="section-1"></a><h2>1. Introduction</h2> 134 <p>This document enumerates the requirements that must be met in order for 135 mobile phones to be compatible with Android 2.3.</p> 136 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 137 "should not", "recommended", "may" and "optional" is per the IETF standard 138 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 139 <p>As used in this document, a "device implementer" or "implementer" is a 140 person or organization developing a hardware/software solution running Android 141 2.3. A "device implementation" or "implementation" is the hardware/software 142 solution so developed.</p> 143 <p>To be considered compatible with Android 2.3, device implementations 144 MUST meet the requirements presented in this Compatibility Definition, 145 including any documents incorporated via reference.</p> 146 <p>Where this definition or the software tests described in <a 147 href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 148 the responsibility of the device implementer to ensure compatibility with 149 existing implementations. For this reason, the Android Open Source Project [<a 150 href="#resources03">Resources, 3</a>] is both the reference and preferred 151 implementation of Android. Device implementers are strongly encouraged to base 152 their implementations to the greatest extent possible on the "upstream" source 153 code available from the Android Open Source Project. While some components can 154 hypothetically be replaced with alternate implementations this practice is 155 strongly discouraged, as passing the software tests will become substantially 156 more difficult. It is the implementer's responsibility to ensure full 157 behavioral compatibility with the standard Android implementation, including 158 and beyond the Compatibility Test Suite. Finally, note that certain component 159 substitutions and modifications are explicitly forbidden by this document.</p> 160 <p>Please note that this Compatibility Definition is issued to correspond with 161 the 2.3.3 update to Android, which is API level 10. This Definition obsoletes 162 and replaces the Compatibility Definition for Android 2.3 versions prior to 163 2.3.3. (That is, versions 2.3.1 and 2.3.2 are obsolete.) Future 164 Android-compatible devices running Android 2.3 MUST ship with version 2.3.3 or 165 later.</p> 166 <a name="section-2"></a><h2>2. Resources</h2> 167 <ol> 168 <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> 169 <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> 170 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 171 <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> 172 <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> 173 <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> 174 <a name="resources07"></a><li>Android 2.3 allowed version strings: <a href="http://source.android.com/compatibility/2.3/versions.html">http://source.android.com/compatibility/2.3/versions.html</a></li> 175 <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> 176 <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> 177 <a name="resources10"></a><li>HTML5 offline capabilities: <a href="http://dev.w3.org/html5/spec/Overview.html#offline">http://dev.w3.org/html5/spec/Overview.html#offline</a></li> 178 <a name="resources11"></a><li>HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></li> 179 <a name="resources12"></a><li>HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></li> 180 <a name="resources13"></a><li>HTML5/W3C webdatabase API: <a href="http://www.w3.org/TR/webdatabase/">http://www.w3.org/TR/webdatabase/</a></li> 181 <a name="resources14"></a><li>HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></li> 182 <a name="resources15"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 183 <a name="resources16"></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> 184 <a name="resources17"></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> 185 <a name="resources18"></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> 186 <a name="resources19"></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> 187 <a name="resources20"></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> 188 <a name="resources21"></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> 189 <a name="resources22"></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> 190 <a name="resources23"></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> 191 <a name="resources24"></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> 192 <a name="resources25"></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> 193 <a name="resources26"></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> 194 <a name="resources27"></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> 195 <a name="resources28"></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> 196 <a name="resources29"></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> 197 <a name="resources30"></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> 198 <a name="resources31"></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> 199 <a name="resources32"></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> 200 <a name="resources33"></a><li>NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></li> 201 <a name="resources34"></a><li>MIFARE MF1S503X: <a href="http://www.nxp.com/documents/data_sheet/MF1S503x.pdf">http://www.nxp.com/documents/data_sheet/MF1S503x.pdf</a></li> 202 <a name="resources35"></a><li>MIFARE MF1S703X: <a href="http://www.nxp.com/documents/data_sheet/MF1S703x.pdf">http://www.nxp.com/documents/data_sheet/MF1S703x.pdf</a></li> 203 <a name="resources36"></a><li>MIFARE MF0ICU1: <a href="http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf">http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf</a></li> 204 <a name="resources37"></a><li>MIFARE MF0ICU2: <a href="http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf">http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf</a></li> 205 <a name="resources38"></a><li>MIFARE AN130511: <a href="http://www.nxp.com/documents/application_note/AN130511.pdf">http://www.nxp.com/documents/application_note/AN130511.pdf</a></li> 206 <a name="resources39"></a><li>MIFARE AN130411: <a href="http://www.nxp.com/documents/application_note/AN130411.pdf">http://www.nxp.com/documents/application_note/AN130411.pdf</a></li> 207 <a name="resources40"></a><li>Camera orientation API: <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)</a></li> 208 <a name="resources41"></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> 209 <a name="resources42"></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> 210 <a name="resources43"></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> 211 </ol> 212 <p>Many of these resources are derived directly or indirectly from the Android 213 2.3 SDK, and will be functionally identical to the information in that SDK's 214 documentation. In any cases where this Compatibility Definition or the 215 Compatibility Test Suite disagrees with the SDK documentation, the SDK 216 documentation is considered authoritative. Any technical details provided in 217 the references included above are considered by inclusion to be part of this 218 Compatibility Definition.</p> 219 220 <a name="section-3"></a><h2>3. Software</h2> 221 <p>The Android platform includes a set of managed APIs, a set of native APIs, 222 and a body of so-called "soft" APIs such as the Intent system and 223 web-application APIs. This section details the hard and soft APIs that are 224 integral to compatibility, as well as certain other relevant technical and 225 user interface behaviors. Device implementations MUST comply with all the 226 requirements in this section.</p> 227 228 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 229 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 230 Android applications. The Android application programming interface (API) is 231 the set of Android platform interfaces exposed to applications running in the 232 managed VM environment. Device implementations MUST provide complete 233 implementations, including all documented behaviors, of any documented API 234 exposed by the Android 2.3 SDK [<a href="#resources04">Resources, 4</a>].</p> 235 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 236 or signatures, deviate from the documented behavior, or include no-ops, except 237 where specifically allowed by this Compatibility Definition.</p> 238 <p>This Compatibility Definition permits some types of hardware for which 239 Android includes APIs to be omitted by device implementations. In such cases, 240 the APIs MUST still be present and behave in a reasonable way. See Section 7 241 for specific requirements for this scenario.</p> 242 243 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 244 <p>In addition to the managed APIs from Section 3.1, Android also includes a 245 significant runtime-only "soft" API, in the form of such things such as 246 Intents, permissions, and similar aspects of Android applications that cannot 247 be enforced at application compile time. This section details the "soft" APIs 248 and system behaviors required for compatibility with Android 2.3. Device 249 implementations MUST meet all the requirements presented in this section.</p> 250 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 251 <p>Device implementers MUST support and enforce all permission constants as 252 documented by the Permission reference page [<a 253 href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional 254 requirements related to the Android security model.</p> 255 <a name="section-3.2.3"></a><h4>3.2.2. Build Parameters</h4> 256 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 257 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 258 the current device. To provide consistent, meaningful values across device 259 implementations, the table below includes additional restrictions on the 260 formats of these values to which device implementations MUST conform.</p> 261 <table> 262 <tbody> 263 <tr> 264 <td><b>Parameter</b></td> 265 <td><b>Comments</b></td> 266 </tr> 267 <tr> 268 <td>android.os.Build.VERSION.RELEASE</td> 269 <td>The version of the currently-executing Android system, in human-readable 270 format. This field MUST have one of the string values defined in [<a 271 href="#resources07">Resources, 7</a>].</td> 272 </tr> 273 <tr> 274 <td>android.os.Build.VERSION.SDK</td> 275 <td>The version of the currently-executing Android system, in a format 276 accessible to third-party application code. For Android 2.3, this field MUST have 277 the integer value 9.</td> 278 </tr> 279 <tr> 280 <td>android.os.Build.VERSION.INCREMENTAL</td> 281 <td>A value chosen by the device implementer designating the specific build of 282 the currently-executing Android system, in human-readable format. This value 283 MUST NOT be re-used for different builds made available to end users. A typical use 284 of this field is to indicate which build number or source-control change 285 identifier was used to generate the build. There are no requirements on the 286 specific format of this field, except that it MUST NOT be null or the empty 287 string ("").</td> 288 </tr> 289 <tr> 290 <td>android.os.Build.BOARD</td> 291 <td>A value chosen by the device implementer identifying the specific internal 292 hardware used by the device, in human-readable format. A possible use of this 293 field is to indicate the specific revision of the board powering the device. 294 The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 295 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 296 </tr> 297 <tr> 298 <td>android.os.Build.BRAND</td> 299 <td>A value chosen by the device implementer identifying the name of the 300 company, organization, individual, etc. who produced the device, in 301 human-readable format. A possible use of this field is to indicate the OEM 302 and/or carrier who sold the device. The value of this field MUST be 303 encodable as 7-bit ASCII and match the regular expression 304 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 305 </td> 306 </tr> 307 <tr> 308 <td>android.os.Build.DEVICE</td> 309 <td>A value chosen by the device implementer identifying the specific 310 configuration or revision of the body (sometimes called "industrial design") 311 of the device. The value of this field MUST be encodable as 7-bit ASCII and 312 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 313 </tr> 314 <tr> 315 <td>android.os.Build.FINGERPRINT</td> 316 <td>A string that uniquely identifies this build. It SHOULD be reasonably 317 human-readable. It MUST follow this template: 318 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 319 For example: 320 <br/><code>acme/mydevice/generic/generic:2.3/ERC77/3359:userdebug/test-keys</code><br/> 321 The fingerprint MUST NOT include whitespace characters. If other fields included in the 322 template above have whitespace characters, they MUST be replaced in the build 323 fingerprint with another character, such as the underscore ("_") character. 324 The value of this field MUST be encodable as 7-bit ASCII.</td> 325 </tr> 326 <tr> 327 <td>android.os.Build.HOST</td> 328 <td>A string that uniquely identifies the host the build was built on, in 329 human readable format. There are no requirements on the specific format of 330 this field, except that it MUST NOT be null or the empty string ("").</td> 331 </tr> 332 <tr> 333 <td>android.os.Build.ID</td> 334 <td>An identifier chosen by the device implementer to refer to a specific 335 release, in human readable format. This field can be the same as 336 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 337 meaningful for end users to distinguish between software builds. The value of 338 this field MUST be encodable as 7-bit ASCII and match the regular expression 339 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 340 </td> 341 </tr> 342 <tr> 343 <td>android.os.Build.MODEL</td> 344 <td>A value chosen by the device implementer containing the name of the device 345 as known to the end user. This SHOULD be the same name under which the device 346 is marketed and sold to end users. There are no requirements on the specific 347 format of this field, except that it MUST NOT be null or the empty string 348 ("").</td> 349 </tr> 350 <tr> 351 <td>android.os.Build.PRODUCT</td> 352 <td>A value chosen by the device implementer containing the development name 353 or code name of the device. MUST be human-readable, but is not necessarily 354 intended for view by end users. The value of this field MUST be 355 encodable as 7-bit ASCII and match the regular expression 356 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 357 </tr> 358 <tr> 359 <td>android.os.Build.TAGS</td> 360 <td>A comma-separated list of tags chosen by the device implementer that 361 further distinguish the build. For example, "unsigned,debug". The value of 362 this field MUST be encodable as 7-bit ASCII and match the regular expression 363 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 364 </tr> 365 <tr> 366 <td>android.os.Build.TIME</td> 367 <td>A value representing the timestamp of when the build occurred.</td> 368 </tr> 369 <tr> 370 <td>android.os.Build.TYPE</td> 371 <td>A value chosen by the device implementer specifying the runtime 372 configuration of the build. This field SHOULD have one of the values 373 corresponding to the three typical Android runtime configurations: "user", 374 "userdebug", or "eng". The value of this field MUST be 375 encodable as 7-bit ASCII and match the regular expression 376 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 377 </tr> 378 <tr> 379 <td>android.os.Build.USER</td> 380 <td>A name or user ID of the user (or automated user) that generated the 381 build. There are no requirements on the specific format of this field, except 382 that it MUST NOT be null or the empty string ("").</td> 383 </tr> 384 </tbody> 385 </table> 386 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 387 <p>Android uses Intents to achieve loosely-coupled integration between 388 applications. This section describes requirements related to the Intent 389 patterns that MUST be honored by device implementations. By "honored", it is 390 meant that the device implementer MUST provide an Android Activity or Service 391 that specifies a matching Intent filter and binds to and implements correct 392 behavior for each specified Intent pattern.</p> 393 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 394 <p>The Android upstream project defines a number of core applications, such as 395 a phone dialer, calendar, contacts book, music player, and so on. Device 396 implementers MAY replace these applications with alternative versions.</p> 397 <p>However, any such alternative versions MUST honor the same Intent patterns 398 provided by the upstream project. For example, if a device contains an 399 alternative music player, it must still honor the Intent pattern issued by 400 third-party applications to pick a song.</p> 401 <p>The following applications are considered core Android system 402 applications:</p> 403 <ul> 404 <li>Desk Clock</li> 405 <li>Browser</li> 406 <li>Calendar</li> 407 <li>Calculator</li> 408 <!-- <li>Camera</li> --> 409 <li>Contacts</li> 410 <li>Email</li> 411 <li>Gallery</li> 412 <li>GlobalSearch</li> 413 <li>Launcher</li> 414 <!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 415 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 416 <!-- <li>Messaging (AKA "Mms")</li> --> 417 <li>Music</li> 418 <!-- <li>Phone</li> --> 419 <li>Settings</li> 420 <!-- <li>SoundRecorder</li> --> 421 </ul> 422 <p>The core Android system applications include various Activity, or Service 423 components that are considered "public". That is, the attribute 424 "android:exported" may be absent, or may have the value "true".</p> 425 <p>For every Activity or Service defined 426 in one of the core Android system apps that is not marked as non-public via an 427 android:exported attribute with the value "false", device implementations MUST 428 include a compontent of the same type implementing the same Intent filter 429 patterns as the core Android system app.</p> 430 <p>In other words, a device implementation MAY replace core Android system 431 apps; however, if it does, the device implementation MUST support all Intent 432 patterns defined by each core Android system app being replaced.</p> 433 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 434 <p>As Android is an extensible platform, device implementers MUST allow each 435 Intent pattern referenced in Section 3.2.3.1 to be overridden by third-party 436 applications. The upstream Android open source project allows this by default; 437 device implementers MUST NOT attach special privileges to system applications' 438 use of these Intent patterns, or prevent third-party applications from binding 439 to and assuming control of these patterns. This prohibition specifically 440 includes but is not limited to disabling the "Chooser" user interface which 441 allows the user to select between multiple applications which all handle the 442 same Intent pattern.</p> 443 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 444 <p>Device implementers MUST NOT include any Android component that honors any 445 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 446 key string in the android.* namespace. Device implementers MUST NOT include 447 any Android components that honor any new Intent or Broadcast Intent patterns 448 using an ACTION, CATEGORY, or other key string in a package space belonging to 449 another organization. Device implementers MUST NOT alter or extend any of the 450 Intent patterns used by the core apps listed in Section 3.2.3.1.</p> 451 <p>This prohibition is analogous to that specified for Java language classes 452 in Section 3.6.</p> 453 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 454 <p>Third-party applications rely on the platform to broadcast certain Intents 455 to notify them of changes in the hardware or software environment. 456 Android-compatible devices MUST broadcast the public broadcast Intents in 457 response to appropriate system events. Broadcast Intents are described in the 458 SDK documentation.</p> 459 460 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 461 <p>Managed code running in Dalvik can call into native code provided in the 462 application .apk file as an ELF .so file compiled for the appropriate device 463 hardware architecture. As native code is highly dependent on the underlying 464 processor technology, Android defines a number of Application Binary 465 Interfaces (ABIs) in the Android NDK, in the file 466 <code>docs/CPU-ARCH-ABIS.txt</code>. If a device implementation is compatible 467 with one or more defined ABIs, it SHOULD implement compatibility with the 468 Android NDK, as below.</p> 469 <p>If a device implementation includes support for an Android ABI, it:</p> 470 <ul> 471 <li>MUST include support for code running in the managed environment to call 472 into native code, using the standard Java Native Interface (JNI) 473 semantics.</li> 474 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible 475 (for the ABI) with each required library in the list below</li> 476 <li>MUST accurately report the native Application Binary Interface (ABI) 477 supported by the device, via the <code>android.os.Build.CPU_ABI</code> 478 API</li> 479 <li>MUST report only those ABIs documented in the latest version of the 480 Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li> 481 <li>SHOULD be built using the source code and header files available in the 482 upstream Android open-source project</li> 483 </ul> 484 <p>The following native code APIs MUST be available to apps that include 485 native code:</p> 486 <ul> 487 <li>libc (C library)</li> 488 <li>libm (math library)</li> 489 <li>Minimal support for C++</li> 490 <li>JNI interface</li> 491 <li>liblog (Android logging)</li> 492 <li>libz (Zlib compression)</li> 493 <li>libdl (dynamic linker)</li> 494 <li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 495 <li>libGLESv2.so (OpenGL ES 2.0)</li> 496 <li>libEGL.so (native OpenGL surface management)</li> 497 <li>libjnigraphics.so</li> 498 <li>libOpenSLES.so (Open Sound Library audio support)</li> 499 <li>libandroid.so (native Android activity support)</li> 500 <li>Support for OpenGL, as described below</li> 501 </ul> 502 <p>Note that future releases of the Android NDK may introduce support for 503 additional ABIs. If a device implementation is not compatible with an existing 504 predefined ABI, it MUST NOT report support for any ABI at all.</p> 505 <p>Native code compatibility is challenging. For this reason, it should be 506 repeated that device implementers are VERY strongly encouraged to use the 507 upstream implementations of the libraries listed above to help ensure 508 compatibility.</p> 509 510 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 511 <p>Many developers and applications rely on the behavior of the 512 <code>android.webkit.WebView</code> class [<a 513 href="#resources08">Resources, 8</a>] 514 for their user interfaces, so the WebView implementation must be 515 compatible across Android implementations. Similarly, a complete, modern web 516 broswer is central to the Android user experience. Device implementations MUST 517 include a version of <code>android.webkit.WebView</code> consistent with the 518 upstream Android software, and MUST include a modern HTML5-capable browser, as 519 described below.</p> 520 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 521 <p>The Android Open Source implementation uses the WebKit rendering engine to 522 implement the <code>android.webkit.WebView</code>. Because it is not feasible 523 to develop a comprehensive test suite for a web rendering system, device 524 implementers MUST use the specific upstream build of WebKit in the WebView 525 implementation. Specifically:</p> 526 <ul> 527 <li>Device implementations' <code>android.webkit.WebView</code> 528 implementations MUST be based on the 533.1 WebKit build from the upstream 529 Android Open Source tree for Android 2.3. This build includes a specific set 530 of functionality and security fixes for the WebView. Device implementers MAY 531 include customizations to the WebKit implementation; however, any such 532 customizations MUST NOT alter the behavior of the WebView, including rendering 533 behavior.</li> 534 <li>The user agent string reported by the WebView MUST be in this format:<br/> 535 <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> 536 <ul> 537 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 538 <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> 539 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 540 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 541 </ul></li> 542 </ul> 543 <p>The WebView component SHOULD include support for as much of HTML5 [<a 544 href="#resources09">Resources, 9</a>] as possible. 545 Minimally, device implementations MUST support each of these APIs associated 546 with HTML5 in the WebView:</p> 547 <ul> 548 <li>application cache/offline operation [<a href="#resources10">Resources, 10</a>]</li> 549 <li>the <video> tag [<a href="#resources11">Resources, 11</a>]</li> 550 <li>geolocation [<a href="#resources12">Resources, 12</a>]</li> 551 </ul> 552 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 553 API [<a href="#resources13">Resources, 13</a>], and SHOULD support the 554 HTML5/W3C IndexedDB API [<a href="#resources14">Resources, 14</a>]. <i>Note 555 that as the web development standards bodies are transitioning to favor 556 IndexedDB over webstorage, IndexedDB is expected to become a required 557 component in a future version of Android.</i></p> 558 <p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a 559 WebView, unless the developer explicitly enables them via the usual Android 560 APIs.</p> 561 562 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 563 <p>Device implementations MUST include a standalone Browser application for 564 general user web browsing. The standalone Browser MAY be based on a 565 browser technology other than WebKit. However, even if an alternate Browser 566 application is used, the <code>android.webkit.WebView</code> component 567 provided to third-party applications MUST be based on WebKit, as described in 568 Section 3.4.1.</p> 569 <p>Implementations MAY ship a custom user agent string in the standalone 570 Browser application.</p> 571 <p>The standalone Browser application (whether based on the upstream 572 WebKit Browser application or a third-party replacement) SHOULD include support 573 for as much of HTML5 [<a href="#resources09">Resources, 9</a>] as possible. 574 Minimally, device implementations MUST support each of these APIs associated 575 with HTML5:</p> 576 <ul> 577 <li>application cache/offline operation [<a href="#resources10">Resources, 10</a>]</li> 578 <li>the <video> tag [<a href="#resources11">Resources, 11</a>]</li> 579 <li>geolocation [<a href="#resources12">Resources, 12</a>]</li> 580 </ul> 581 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 582 API [<a href="#resources13">Resources, 13</a>], and SHOULD support the 583 HTML5/W3C IndexedDB API [<a href="#resources14">Resources, 14</a>]. <i>Note 584 that as the web development standards bodies are transitioning to favor 585 IndexedDB over webstorage, IndexedDB is expected to become a required 586 component in a future version of Android.</i></p> 587 588 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 589 <p>The behaviors of each of the API types (managed, soft, native, and web) 590 must be consistent with the preferred implementation of the upstream Android 591 open-source project [<a href="#resources03">Resources, 3</a>]. Some specific areas 592 of compatibility are:</p> 593 <ul> 594 <li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 595 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 596 particular type of system component (such as Service, Activity, 597 ContentProvider, etc.)</li> 598 <li>Devices MUST NOT change the semantics of a standard permission</li> 599 </ul> 600 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 601 tests significant portions of the platform for behavioral compatibility, but 602 not all. It is the responsibility of the implementer to ensure behavioral 603 compatibility with the Android Open Source Project. For this reason, device 604 implementers SHOULD use the source code available via the Android Open Source 605 Project where possible, rather than re-implement significant parts of the 606 system.</p> 607 608 609 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 610 <p>Android follows the package and class namespace conventions defined by the 611 Java programming language. To ensure compatibility with third-party 612 applications, device implementers MUST NOT make any prohibited modifications 613 (see below) to these package namespaces:</p> 614 <ul> 615 <li>java.*</li> 616 <li>javax.*</li> 617 <li>sun.*</li> 618 <li>android.*</li> 619 <li>com.android.*</li> 620 </ul> 621 <p>Prohibited modifications include:</p> 622 <ul> 623 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 624 Android platform by changing any method or class signatures, or by removing 625 classes or class fields.</li> 626 <li>Device implementers MAY modify the underlying implementation of the APIs, 627 but such modifications MUST NOT impact the stated behavior and Java-language 628 signature of any publicly exposed APIs.</li> 629 <li>Device implementers MUST NOT add any publicly exposed elements (such as 630 classes or interfaces, or fields or methods to existing classes or interfaces) 631 to the APIs above.</li> 632 </ul> 633 <p>A "publicly exposed element" is any construct which is not decorated with 634 the "@hide" marker as used in the upstream Android source code. In other 635 words, device implementers MUST NOT expose new APIs or alter existing APIs in 636 the namespaces noted above. Device implementers MAY make internal-only 637 modifications, but those modifications MUST NOT be advertised or otherwise 638 exposed to developers.</p> 639 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 640 namespace owned by or referring to another organization. For instance, device 641 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 642 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 643 namespaces. Additionally, if a device implementation includes custom APIs 644 outside the standard Android namespace, those APIs MUST be packaged in an 645 Android shared library so that only apps that explicitly use them (via the 646 <code><uses-library></code> mechanism) are affected by the increased 647 memory usage of such APIs.</p> 648 <p>If a device implementer proposes to improve one of the package namespaces 649 above (such as by adding useful new functionality to an existing API, or 650 adding a new API), the implementer SHOULD visit source.android.com and begin 651 the process for contributing changes and code, according to the information on 652 that site.</p> 653 <p>Note that the restrictions above correspond to standard conventions for 654 naming APIs in the Java programming language; this section simply aims to 655 reinforce those conventions and make them binding through inclusion in this 656 compatibility definition.</p> 657 658 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 659 <p>Device implementations MUST support the full Dalvik Executable (DEX) 660 bytecode specification and Dalvik Virtual Machine semantics [<a 661 href="#resources15">Resources, 15</a>].</p> 662 <p>Device implementations with screens classified as medium- or low-density 663 MUST configure Dalvik to allocate at least 16MB of memory to each application. 664 Device implementations with screens classified as high-density or 665 extra-high-density MUST configure Dalvik to allocate at least 24MB of memory 666 to each application. Note that device implementations MAY allocate more memory 667 than these figures.</p> 668 669 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 670 <p>The Android platform includes some developer APIs that allow developers to 671 hook into the system user interface. Device implementations MUST incorporate 672 these standard UI APIs into custom user interfaces they develop, as explained 673 below.</p> 674 <a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4> 675 <p>Android defines a component type and corresponding API and lifecycle that 676 allows applications to expose an "AppWidget" to the end user [<a 677 href="#resources16">Resources, 16</a>]. 678 The Android Open Source reference release includes a Launcher application that 679 includes user interface elements allowing the user to add, view, and remove 680 AppWidgets from the home screen.</p> 681 <p>Device implementers MAY substitute an alternative to the reference Launcher 682 (i.e. home screen). Alternative Launchers SHOULD include built-in support for 683 AppWidgets, and expose user interface elements to add, configure, view, and remove 684 AppWidgets directly within the Launcher. Alternative Launchers MAY omit these 685 user interface elements; however, if they are omitted, the device implementer 686 MUST provide a separate application accessible from the Launcher that allows 687 users to add, configure, view, and remove AppWidgets.</p> 688 <a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4> 689 <p>Android includes APIs that allow developers to notify users of notable 690 events [<a href="#resources17">Resources, 17</a>]. Device implementers MUST provide support for each 691 class of notification so defined; specifically: sounds, vibration, light and 692 status bar.</p> 693 <p>Additionally, the implementation MUST correctly render all resources 694 (icons, sound files, etc.) provided for in the APIs [<a 695 href="#resources18">Resources, 18</a>], or in the 696 Status Bar icon style guide [<a href="#resources19">Resources, 19</a>]. Device implementers MAY provide 697 an alternative user experience for notifications than that provided by the 698 reference Android Open Source implementation; however, such alternative 699 notification systems MUST support existing notification resources, as 700 above.</p> 701 <a name="section-3.8.3"></a><h4>3.8.3. Search</h4> 702 <p>Android includes APIs [<a href="#resources20">Resources, 20</a>] that allow developers to incorporate 703 search into their applications, and expose their application's data into the 704 global system search. Generally speaking, this functionality consists of a 705 single, system-wide user interface that allows users to enter queries, 706 displays suggestions as users type, and displays results. The Android APIs 707 allow developers to reuse this interface to provide search within their own 708 apps, and allow developers to supply results to the common global search user 709 interface.</p> 710 <p>Device implementations MUST include a single, shared, system-wide search 711 user interface capable of real-time suggestions in response to user input. 712 Device implementations MUST implement the APIs that allow developers to reuse 713 this user interface to provide search within their own applications. Device 714 implementations MUST implement the APIs that allow third-party applications to 715 add suggestions to the search box when it is run in global search mode. If no 716 third-party applications are installed that make use of this functionality, 717 the default behavior SHOULD be to display web search engine results and 718 suggestions.</p> 719 <p>Device implementations MAY ship alternate search user interfaces, but 720 SHOULD include a hard or soft dedicated search button, that can be used at any 721 time within any app to invoke the search framework, with the behavior provided 722 for in the API documentation.</p> 723 <a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4> 724 <p>Applications can use the "Toast" API (defined in [<a 725 href="#resources21">Resources, 21</a>]) to 726 display short non-modal strings to the end user, that disappear after a brief 727 period of time. Device implementations MUST display Toasts from applications 728 to end users in some high-visibility manner.</p> 729 <a name="section-3.8.5"></a><h4>3.8.5. Live Wallpapers</h4> 730 <p>Android defines a component type and corresponding API and lifecycle that 731 allows applications to expose one or more "Live Wallpapers" to the end user 732 [<a href="#resources22">Resources, 22</a>]. Live Wallpapers are animations, 733 patterns, or similar images with limited input capabilities that display as a 734 wallpaper, behind other applications.</p> 735 <p>Hardware is considered capable of reliably running live wallpapers if it 736 can run all live wallpapers, with no limitations on functionality, at a 737 reasonable framerate with no adverse affects on other applications. If 738 limitations in the hardware cause wallpapers and/or applications to crash, 739 malfunction, consume excessive CPU or battery power, or run at unacceptably 740 low frame rates, the hardware is considered incapable of running live 741 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 742 context to render their content. Live wallpaper will not run reliably on 743 hardware that does not support multiple OpenGL contexts because the live 744 wallpaper use of an OpenGL context may conflict with other applications that 745 also use an OpenGL context.</p> 746 <p>Device implementations capable of running live wallpapers reliably as 747 described above SHOULD implement live wallpapers. Device implementations 748 determined to not run live wallpapers reliably as described above MUST NOT 749 implement live wallpapers.</p> 750 751 <a name="section-4"></a><h2>4. Application Packaging Compatibility</h2> 752 <p>Device implementations MUST install and run Android ".apk" files as 753 generated by the "aapt" tool included in the official Android SDK [<a 754 href="#resources23">Resources, 23</a>].</p> 755 <p>Devices implementations MUST NOT extend either the .apk [<a 756 href="#resources24">Resources, 24</a>], Android Manifest [<a 757 href="#resources25">Resources, 25</a>], 758 or Dalvik bytecode [<a href="#resources15">Resources, 15</a>] formats in such 759 a way that would prevent those files from 760 installing and running correctly on other compatible devices. Device 761 implementers SHOULD use the reference upstream implementation of Dalvik, and 762 the reference implementation's package management system.</p> 763 764 <a name="section-5"></a><h2>5. Multimedia Compatibility</h2> 765 <p>Device implementations MUST fully implement all multimedia APIs. Device 766 implementations MUST include support for all multimedia codecs described 767 below, and SHOULD meet the sound processing guidelines described below. Device 768 implementations MUST include at least one form of audio output, such as 769 speakers, headphone jack, external speaker connection, etc.</p> 770 <a name="section-5.1"></a><h3>5.1. Media Codecs</h3> 771 <p>Device implementations MUST support the multimedia codecs as detailed in 772 the following sections. All of these codecs are provided as software 773 implementations in the preferred Android implementation from the Android 774 Open-Source Project.</p> 775 <p>Please note that neither Google nor the Open Handset Alliance make any 776 representation that these codecs are unencumbered by third-party patents. 777 Those intending to use this source code in hardware or software products are 778 advised that implementations of this code, including in open source software 779 or shareware, may require patent licenses from the relevant patent 780 holders.</p> 781 <p>The tables below do not list specific bitrate requirements for 782 most video codecs. The reason for this is that in practice, current device 783 hardware does not necessarily support bitrates that map exactly to the 784 required bitrates specified by the relevant standards. Instead, device 785 implementations SHOULD support the highest bitrate practical on the hardware, 786 up to the limits defined by the specifications.</p> 787 <a name="section-5.1.1"></a><h3>5.1.1. Media Decoders</h3> 788 <p>Device implementations MUST include an implementation of an decoder for 789 each codec and format described in the table below. Note that decoders for 790 each of these media types are provided by the upstream Android Open-Source 791 Project.</p> 792 <table><tbody> 793 <tr> 794 <td rowspan="11"><b>Audio</b></td> 795 </tr> 796 <tr> 797 <td><b>Name</b></td> 798 <td><b>Details</b></td> 799 <td><b>File/Container Format</b></td> 800 </tr> 801 <tr> 802 <td>AAC LC/LTP</td> 803 <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> 804 <td rowspan="3">3GPP (.3gp) and MPEG-4 (.mp4, .m4a). No support for raw AAC (.aac)</td> 805 </tr> 806 <tr> 807 <td>HE-AACv1 (AAC+)</td> 808 </tr> 809 <tr> 810 <td>HE-AACv2 (enhanced AAC+)</td> 811 </tr> 812 <tr> 813 <td>AMR-NB</td> 814 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 815 <td>3GPP (.3gp)</td> 816 </tr> 817 <tr> 818 <td>AMR-WB</td> 819 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 820 <td>3GPP (.3gp)</td> 821 </tr> 822 <tr> 823 <td>MP3</td> 824 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR)</td> 825 <td>MP3 (.mp3)</td> 826 </tr> 827 <tr> 828 <td>MIDI</td> 829 <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> 830 <td>Type 0 and 1 (.mid, .xmf, .mxmf). Also RTTTL/RTX (.rtttl, .rtx), OTA (.ota), and iMelody (.imy)</td> 831 </tr> 832 <tr> 833 <td>Ogg Vorbis</td> 834 <td> </td> 835 <td>Ogg (.ogg)</td> 836 </tr> 837 <tr> 838 <td>PCM</td> 839 <td>8- and 16-bit linear PCM (rates up to limit of hardware)</td> 840 <td>WAVE (.wav)</td> 841 </tr> 842 <tr> 843 <td rowspan="5"><b>Image</b></td> 844 </tr> 845 <tr> 846 <td>JPEG</td> 847 <td>base+progressive</td> 848 <td> </td> 849 </tr> 850 <tr> 851 <td>GIF</td> 852 <td> </td> 853 <td> </td> 854 </tr> 855 <tr> 856 <td>PNG</td> 857 <td> </td> 858 <td> </td> 859 </tr> 860 <tr> 861 <td>BMP</td> 862 <td> </td> 863 <td> </td> 864 </tr> 865 <tr> 866 <td rowspan="4"><b>Video</b></td> 867 </tr> 868 <tr> 869 <td>H.263</td> 870 <td> </td> 871 <td>3GPP (.3gp) files</td> 872 </tr> 873 <tr> 874 <td>H.264</td> 875 <td> </td> 876 <td>3GPP (.3gp) and MPEG-4 (.mp4) files</td> 877 </tr> 878 <tr> 879 <td>MPEG4 Simple Profile</td> 880 <td> </td> 881 <td>3GPP (.3gp) file</td> 882 </tr> 883 </tbody> 884 </table> 885 886 <a name="section-5.1.2"></a><h3>5.1.2. Media Encoders</h3> 887 <p>Device implementations SHOULD include encoders for as many of the media 888 formats listed in Section 5.1.1. as possible. However, some encoders do not 889 make sense for devices that lack certain optional hardware; for instance, 890 an encoder for the H.263 video does not make sense, if the device lacks any 891 cameras. Device implementations MUST therefore implement media encoders 892 according to the conditions described in the table below.</p> 893 <p>See Section 7 for details on the conditions under which hardware may be 894 omitted by device implementations.</p> 895 <table><tbody> 896 <tr> 897 <td rowspan="5"><b>Audio</b></td> 898 </tr> 899 <tr> 900 <td><b>Name</b></td> 901 <td><b>Details</b></td> 902 <td><b>File/Container Format</b></td> 903 <td><b>Conditions</b></td> 904 </tr> 905 <tr> 906 <td>AMR-NB</td> 907 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 908 <td>3GPP (.3gp)</td> 909 <td rowspan="3">Device implementations that include microphone hardware and define 910 <code>android.hardware.microphone</code> MUST include encoders for these audio 911 formats.</td> 912 </tr> 913 <tr> 914 <td>AMR-WB</td> 915 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 916 <td>3GPP (.3gp)</td> 917 </tr> 918 <tr> 919 <td>AAC LC/LTP</td> 920 <td rowspan="1">Mono/Stereo content in any combination of standard bit rates up to 160 kbps and sampling rates between 8 to 48kHz</td> 921 <td rowspan="1">3GPP (.3gp) and MPEG-4 (.mp4, .m4a).</td> 922 </tr> 923 <tr> 924 <td rowspan="2"><b>Image</b></td> 925 <td>JPEG</td> 926 <td>base+progressive</td> 927 <td> </td> 928 <td rowspan="2">All device implementations MUST include encoders for these 929 image formats, as Android 2.3 includes APIs that applications can use to 930 programmatically generate files of these types.</td> 931 </tr> 932 <tr> 933 <td>PNG</td> 934 <td> </td> 935 <td> </td> 936 </tr> 937 <tr> 938 <td><b>Video</b></td> 939 <td>H.263</td> 940 <td> </td> 941 <td>3GPP (.3gp) files</td> 942 <td>Device implementations that include camera hardware and define 943 either <code>android.hardware.camera</code> or 944 <code>android.hardware.camera.front</code> MUST include encoders for these 945 video formats.</td> 946 </tr> 947 </tbody> 948 </table> 949 <p>In addition to the encoders listed above, device implementations SHOULD include an H.264 950 encoder. Note that the Compatibility Definition for a future version is planned 951 to change this requirement to "MUST". That is, H.264 encoding is optional in Android 952 2.3 but <b>will be required</b> by a future version. Existing and new devices 953 that run Android 2.3 are <b>very strongly encouraged to meet 954 this requirement in Android 2.3</b>, or they will not be able to attain 955 Android compatibility when upgraded to the future version.</p> 956 957 <a name="section-5.2"></a><h3>5.2. Audio Recording</h3> 958 <p>When an application has used the <code>android.media.AudioRecord</code> API to 959 start recording an audio stream, device implementations SHOULD sample and 960 record audio with each of these behaviors:</p> 961 <ul> 962 <li>Noise reduction processing, if present, SHOULD be disabled.</li> 963 <li>Automatic gain control, if present, SHOULD be disabled.</li> 964 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 965 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 966 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 967 (SPL) source at 1000 Hz yields RMS of 5000 for 16-bit samples.</li> 968 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 969 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 970 <li>Total harmonic distortion SHOULD be less than 1% from 100 Hz to 4000 Hz at 971 90 dB SPL input level.</li> 972 </ul> 973 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD" 974 for Android 2.3, the Compatibility Definition for a future version is planned 975 to change these to "MUST". That is, these requirements are optional in Android 976 2.3 but <b>will be required</b> by a future version. Existing and new devices 977 that run Android 2.3 are <b>very strongly encouraged to meet 978 these requirements in Android 2.3</b>, or they will not be able to attain 979 Android compatibility when upgraded to the future version.</p> 980 981 <a name="section-5.3"></a><h3>5.3. Audio Latency</h3> 982 <p>Audio latency is broadly defined as the interval between when an 983 application requests an audio playback or record operation, and when the 984 device implementation actually begins the operation. Many classes of 985 applications rely on short latencies, to achieve real-time effects such sound 986 effects or VOIP communication. Device implementations that include microphone 987 hardware and declare <code>android.hardware.microphone</code> SHOULD meet all 988 audio latency requirements outlined in this section. See Section 7 for 989 details on the conditions under which microphone hardware may be omitted by 990 device implementations.</p> 991 <p>For the purposes of this section:</p> 992 <ul> 993 <li>"cold output latency" is defined to be the interval between when an 994 application requests audio playback and when sound begins playing, when 995 the audio system has been idle and powered down prior to the request</li> 996 <li>"warm output latency" is defined to be the interval between when an 997 application requests audio playback and when sound begins playing, when 998 the audio system has been recently used but is currently idle (that is, 999 silent)</li> 1000 <li>"continuous output latency" is defined to be the interval between when an 1001 application issues a sample to be played and when the speaker physically 1002 plays the corresponding sound, while the device is currently playing back 1003 audio</li> 1004 <li>"cold input latency" is defined to be the interval between when an 1005 application requests audio recording and when the first sample is 1006 delivered to the application via its callback, when the audio system and 1007 microphone has been idle and powered down prior to the request</li> 1008 <li>"continuous input latency" is defined to be when an ambient sound occurs 1009 and when the sample corresponding to that sound is delivered to a 1010 recording application via its callback, while the device is in recording 1011 mode</li> 1012 </ul> 1013 <p>Using the above definitions, device implementations SHOULD exhibit each of 1014 these properties:</p> 1015 <ul> 1016 <li>cold output latency of 100 milliseconds or less</li> 1017 <li>warm output latency of 10 milliseconds or less</li> 1018 <li>continuous output latency of 45 milliseconds or less</li> 1019 <li>cold input latency of 100 milliseconds or less</li> 1020 <li>continuous input latency of 50 milliseconds or less</li> 1021 </ul> 1022 <p><b>Note:</b> while the requirements outlined above are stated as "SHOULD" 1023 for Android 2.3, the Compatibility Definition for a future version is planned 1024 to change these to "MUST". That is, these requirements are optional in Android 1025 2.3 but <b>will be required</b> by a future version. Existing and new devices 1026 that run Android 2.3 are <b>very strongly encouraged to meet 1027 these requirements in Android 2.3</b>, or they will not be able to attain 1028 Android compatibility when upgraded to the future version.</p> 1029 <p>If a device implementation meets the requirements of this section, it MAY 1030 report support for low-latency audio, by reporting the feature 1031 "android.hardware.audio.low-latency" via the 1032 <code>android.content.pm.PackageManager</code> class. [<a 1033 href="#resources27">Resources, 27</a>] Conversely, if the device 1034 implementation does not meet these requirements it MUST NOT report support for 1035 low-latency audio.</p> 1036 1037 <a name="section-6"></a><h2>6. Developer Tool Compatibility</h2> 1038 <p>Device implementations MUST support the Android Developer Tools provided in 1039 the Android SDK. Specifically, Android-compatible devices MUST be compatible 1040 with:</p> 1041 <ul> 1042 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources23">Resources, 23</a>]<br/> 1043 Device implementations MUST support all <code>adb</code> functions as 1044 documented in the Android SDK. The device-side <code>adb</code> daemon SHOULD 1045 be inactive by default, but there MUST be a user-accessible mechanism to turn 1046 on the Android Debug Bridge.</li> 1047 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources23">Resources, 23</a>]<br/> 1048 Device implementations MUST support all <code>ddms</code> features as documented in the 1049 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1050 <code>ddms</code> SHOULD be inactive by default, 1051 but MUST be supported whenever the user has activated the Android Debug 1052 Bridge, as above.</li> 1053 <li><b>Monkey</b> [<a href="#resources26">Resources, 26</a>]<br/> 1054 Device implementations MUST include the Monkey framework, and make it 1055 available for applications to use.</li> 1056 </ul> 1057 <p>Most Linux-based systems and Apple Macintosh systems recognize Android 1058 devices using the standard Android SDK tools, without additional support; 1059 however Microsoft Windows systems typically require a driver for new Android 1060 devices. (For instance, new vendor IDs and sometimes new device IDs require 1061 custom USB drivers for Windows systems.) If a device implementation is 1062 unrecognized by the <code>adb</code> tool as provided in the standard Android 1063 SDK, device implementers MUST provide Windows drivers allowing developers to 1064 connect to the device using the <code>adb</code> protocol. These drivers MUST 1065 be provided for Windows XP, Windows Vista, and Windows 7, in both 32-bit and 1066 64-bit versions.</p> 1067 1068 <a name="section-7"></a><h2>7. Hardware Compatibility</h2> 1069 <p>Android is intended to enable device implementers to create innovative form 1070 factors and configurations. At the same time Android developers write 1071 innovative applications that rely on the various hardware and features 1072 available through the Android APIs. The requirements in this section strike a 1073 balance between innovations available to device implementers, and the needs of 1074 developers to ensure their apps are only available to devices where they will 1075 run properly.</p> 1076 <p>If a device includes a particular hardware component that has a 1077 corresponding API for third-party developers, the device implementation MUST 1078 implement that API as described in the Android SDK documentation. If an API in 1079 the SDK interacts with a hardware component that is stated to be optional and the device 1080 implementation does not possess that component:</p> 1081 <ul> 1082 <li>complete class definitions (as documented by the SDK) for the component's APIs MUST still be present</li> 1083 <li>the API's behaviors MUST be implemented as no-ops in some reasonable fashion</li> 1084 <li>API methods MUST return null values where permitted by the SDK documentation</li> 1085 <li>API methods MUST return no-op implementations of classes where null values are not permitted by the SDK documentation</li> 1086 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation</li> 1087 </ul> 1088 <p>A typical example of a scenario where these requirements apply is the 1089 telephony API: even on non-phone devices, these APIs must be implemented as 1090 reasonable no-ops.</p> 1091 <p>Device implementations MUST accurately report accurate hardware configuration 1092 information via the <code>getSystemAvailableFeatures()</code> and 1093 <code>hasSystemFeature(String)</code> methods on the 1094 <code>android.content.pm.PackageManager</code> class. [<a 1095 href="#resources27">Resources, 27</a>]</p> 1096 1097 <a name="section-7.1"></a><h3>7.1. Display and Graphics</h3> 1098 <p>Android 2.3 includes facilities that automatically adjust application 1099 assets and UI layouts appropriately for the device, to ensure that third-party 1100 applications run well on a variety of hardware configurations [<a 1101 href="#resources28">Resources, 28</a>]. Devices MUST properly implement these 1102 APIs and behaviors, as detailed in this section.</p> 1103 <a name="section-7.1.1"></a><h4>7.1.1. Screen Configurations</h4> 1104 <p>Device implementations MAY use screens of any pixel dimensions, provided 1105 that they meet the following requirements:</p> 1106 <ul> 1107 <li>screens MUST be at least 2.5 inches in physical diagonal size</li> 1108 <li>density MUST be at least 100 dpi</li> 1109 <li>the aspect ratio MUST be between 1.333 (4:3) and 1.779 (16:9)</li> 1110 <li>the display technology used consists of square pixels</li> 1111 </ul> 1112 <p>Device implementations with a screen meeting the requirements above are 1113 considered compatible, and no additional action is necessary. The Android 1114 framework implementation automatically computes display characteristics such 1115 as screen size bucket and density bucket. In the majority of cases, the 1116 framework decisions are the correct ones. If the default framework 1117 computations are used, no additional action is necessary. Device implementers 1118 wishing to change the defaults, or use a screen that does not meet the 1119 requirements above MUST contact the Android Compatibility Team for guidance, 1120 as provided for in Section 12.</p> 1121 <p>The units used by the requirements above are defined as follows:</p> 1122 <ul> 1123 <li>"Physical diagonal size" is the distance in inches between two opposing 1124 corners of the illuminated portion of the display.</li> 1125 <li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1126 linear horizontal or vertical span of 1". Where dpi values are listed, both 1127 horizontal and vertical dpi must fall within the range.</li> 1128 <li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1129 shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1130 = 1.779, or roughly "16:9".</li> 1131 </ul> 1132 <p>Device implementations MUST use only displays with a single static 1133 configuration. That is, device implementations MUST NOT enable multiple 1134 screen configurations. For instance, since a typical television supports 1135 multiple resolutions such as 1080p, 720p, and so on, this configuration is not 1136 compatible with Android 2.3. (However, support for such configurations is 1137 under investigation and planned for a future version of Android.)</p> 1138 <a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4> 1139 <p>Device implementations MUST report correct values for all display metrics 1140 defined in <code>android.util.DisplayMetrics</code> [<a 1141 href="#resources29">Resources, 29</a>].</p> 1142 <a name="section-7.1.3"></a><h4>7.1.3. Declared Screen Support</h4> 1143 <p>Applications optionally indicate which screen sizes they support via the 1144 <code><supports-screens></code> attribute in the AndroidManifest.xml 1145 file. Device implementations MUST correctly honor applications' stated support 1146 for small, medium, and large screens, as described in the Android 1147 SDK documentation.</p> 1148 <a name="section-7.1.4"></a><h4>7.1.4. Screen Orientation</h4> 1149 <p>Compatible devices MUST support dynamic orientation by applications to 1150 either portrait or landscape screen orientation. That is, the device must 1151 respect the application's request for a specific screen orientation. Device 1152 implementations MAY select either portrait or landscape orientation as the 1153 default. Devices that cannot be physically rotated MAY meet this requirement 1154 by "letterboxing" applications that request portrait mode, using only a 1155 portion of the available display.</p> 1156 <p>Devices MUST report the correct value for the device's current orientation, 1157 whenever queried via the android.content.res.Configuration.orientation, 1158 android.view.Display.getOrientation(), or other APIs.</p> 1159 <a name="section-7.1.5"></a><h4>7.1.5. 3D Graphics Acceleration</h4> 1160 <p>Device implementations MUST support OpenGL ES 1.0, as required by the 1161 Android 2.3 APIs. For devices that lack 3D acceleration hardware, a software 1162 implementation of OpenGL ES 1.0 is provided by the upstream Android 1163 Open-Source Project. Device implementations SHOULD support OpenGL ES 2.0.</p> 1164 <p>Implementations MAY omit Open GL ES 2.0 support; however if support is 1165 ommitted, device implementations MUST NOT report as supporting OpenGL ES 2.0. 1166 Specifically, if a device implementations lacks OpenGL ES 2.0 support:</p> 1167 <ul> 1168 <li>the managed APIs (such as via the <code>GLES10.getString()</code> method) 1169 MUST NOT report support for OpenGL ES 2.0</li> 1170 <li>the native C/C++ OpenGL APIs (that is, those available to apps via 1171 libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST NOT report support for 1172 OpenGL ES 2.0.</li> 1173 </ul> 1174 <p>Conversely, if a device implementation <i>does</i> support OpenGL ES 2.0, 1175 it MUST accurately report that support via the routes just listed.</p> 1176 <p>Note that Android 2.3 includes support for applications to optionally 1177 specify that they require specific OpenGL texture compression formats. These 1178 formats are typically vendor-specific. Device implementations are not required 1179 by Android 2.3 to implement any specific texture compression format. However, 1180 they SHOULD accurately report any texture compression formats that they do 1181 support, via the <code>getString()</code> method in the OpenGL API.</p> 1182 1183 <a name="section-7.2"></a><h3>7.2. Input Devices</h3> 1184 <p>Android 2.3 supports a number of modalities for user input. Device 1185 implementations MUST support user input devices as provided for in this 1186 section.</p> 1187 <a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4> 1188 <p>Device implementations:</p> 1189 <ul> 1190 <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> 1191 <li>MUST provide at least one soft keyboard implementation (regardless of whether a hard keyboard is present)</li> 1192 <li>MAY include additional soft keyboard implementations</li> 1193 <li>MAY include a hardware keyboard</li> 1194 <li>MUST NOT include a hardware keyboard that does not match one of the 1195 formats specified in <code>android.content.res.Configuration.keyboard</code> 1196 [<a href="#resources30">Resources, 30</a>] (that is, QWERTY, or 12-key)</li> 1197 </ul> 1198 <a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4> 1199 <p>Device implementations:</p> 1200 <ul> 1201 <li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, or wheel)</li> 1202 <li>MUST report the correct value for 1203 <code>android.content.res.Configuration.navigation</code> [<a href="#resources30">Resources, 30</a>]</li> 1204 <li>MUST provide a reasonable alternative user interface mechanism for the 1205 selection and editing of text, compatible with Input Management Engines. The 1206 upstream Android Open-Source code includes a selection mechanism suitable for 1207 use with devices that lack non-touch navigation inputs.</li> 1208 </ul> 1209 <a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4> 1210 <p>The Home, Menu and Back functions are essential to the Android navigation 1211 paradigm. Device implementations MUST make these functions available to the 1212 user at all times, regardless of application state. These functions SHOULD be 1213 implemented via dedicated buttons. They MAY be implemented using software, 1214 gestures, touch panel, etc., but if so they MUST be always accessible and not 1215 obscure or interfere with the available application display area.</p> 1216 <p>Device implementers SHOULD also provide a dedicated search key. Device 1217 implementers MAY also provide send and end keys for phone calls.</p> 1218 <a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4> 1219 <p>Device implementations:</p> 1220 <ul> 1221 <li>MUST have a touchscreen</li> 1222 <li>MAY have either capacitive or resistive touchscreen</li> 1223 <li>MUST report the value of <code>android.content.res.Configuration</code> 1224 [<a href="#resources30">Resources, 30</a>] 1225 reflecting corresponding to the type of the specific touchscreen on the 1226 device</li> 1227 <li>SHOULD support fully independently tracked pointers, if the touchscreen supports multiple pointers</li> 1228 </ul> 1229 1230 <a name="section-7.3"></a><h3>7.3. Sensors</h3> 1231 <p>Android 2.3 includes APIs for accessing a variety of sensor types. Devices 1232 implementations generally MAY omit these sensors, as provided for in the 1233 following subsections. If a device includes a particular sensor type that has a 1234 corresponding API for third-party developers, the device implementation MUST 1235 implement that API as described in the Android SDK documentation. For example, 1236 device implementations:</p> 1237 <ul> 1238 <li>MUST accurately report the presence or absence of sensors per the 1239 <code>android.content.pm.PackageManager</code> class. [<a 1240 href="#resources27">Resources, 27</a>]</li> 1241 <li>MUST return an accurate list of supported sensors via the 1242 <code>SensorManager.getSensorList()</code> and similar methods</li> 1243 <li>MUST behave reasonably for all other sensor APIs (for example, by 1244 returning true or false as appropriate when applications attempt to register 1245 listeners, not calling sensor listeners when the corresponding sensors are not 1246 present; etc.)</li> 1247 </ul> 1248 <p>The list above is not comprehensive; the documented behavior of the Android 1249 SDK is to be considered authoritative.</p> 1250 <p>Some sensor types are synthetic, meaning they can be derived from data 1251 provided by one or more other sensors. (Examples include the orientation 1252 sensor, and the linear acceleration sensor.) Device implementations SHOULD 1253 implement these sensor types, when they include the prerequisite physical 1254 sensors.</p> 1255 <p>The Android 2.3 APIs introduce a notion of a "streaming" sensor, which is 1256 one that returns data continuously, rather than only when the data changes. 1257 Device implementations MUST continuously provide periodic data samples for any 1258 API indicated by the Android 2.3 SDK documentation to be a streaming 1259 sensor.</p> 1260 <a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4> 1261 <p>Device implementations SHOULD include a 3-axis accelerometer. If a device 1262 implementation does include a 3-axis accelerometer, it:</p> 1263 <ul> 1264 <li>MUST be able to deliver events at 50 Hz or greater</li> 1265 <li>MUST comply with the Android sensor coordinate system as detailed 1266 in the Android APIs (see [<a href="#resources31">Resources, 31</a>])</li> 1267 <li>MUST be capable of measuring from freefall up to twice gravity (2g) or 1268 more on any three-dimensional vector</li> 1269 <li>MUST have 8-bits of accuracy or more</li> 1270 <li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 1271 </ul> 1272 <a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4> 1273 <p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 1274 If a device does include a 3-axis magnetometer, it:</p> 1275 <ul> 1276 <li>MUST be able to deliver events at 10 Hz or greater</li> 1277 <li>MUST comply with the Android sensor coordinate system as detailed 1278 in the Android APIs (see [<a href="#resources31">Resources, 31</a>]).</li> 1279 <li>MUST be capable of sampling a range of field strengths adequate to cover the geomagnetic field</li> 1280 <li>MUST have 8-bits of accuracy or more</li> 1281 <li>MUST have a standard deviation no greater than 0.5 µT</li> 1282 </ul> 1283 <a name="section-7.3.3"></a><h4>7.3.3. GPS</h4> 1284 <p>Device implementations SHOULD include a GPS receiver. If a device 1285 implementation does include a GPS receiver, it SHOULD include 1286 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1287 <a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4> 1288 <p>Device implementations SHOULD include a gyroscope (i.e. angular change 1289 sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 1290 accelerometer is also included. If a device implementation includes a 1291 gyroscope, it:</p> 1292 <ul> 1293 <li>MUST be capable of measuring orientation changes up to 5.5*Pi 1294 radians/second (that is, approximately 1,000 degrees per second)</li> 1295 <li>MUST be able to deliver events at 100 Hz or greater</li> 1296 <li>MUST have 8-bits of accuracy or more</li> 1297 </ul> 1298 <a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4> 1299 <p>Device implementations MAY include a barometer (i.e. ambient air pressure 1300 sensor.) If a device implementation includes a barometer, it:</p> 1301 <ul> 1302 <li>MUST be able to deliver events at 5 Hz or greater</li> 1303 <li>MUST have adequate precision to enable estimating altitude</li> 1304 </ul> 1305 <a name="section-7.3.6"></a><h4>7.3.7. Thermometer</h4> 1306 <p>Device implementations MAY but SHOULD NOT include a thermometer (i.e. 1307 temperature sensor.) If a device implementation does include a thermometer, it 1308 MUST measure the temperature of the device CPU. It MUST NOT measure any other 1309 temperature. (Note that this sensor type is deprecated in the Android 2.3 1310 APIs.)</p> 1311 <a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4> 1312 <p>Device implementations MAY include a photometer (i.e. ambient light 1313 sensor.)</p> 1314 <a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4> 1315 <p>Device implementations MAY include a proximity sensor. If a device 1316 implementation does include a proximity sensor, it MUST measure the proximity 1317 of an object in the same direction as the screen. That is, the proximity 1318 sensor MUST be oriented to detect objects close to the screen, as the 1319 primary intent of this sensor type is to detect a phone in use by the 1320 user. If a device implementation includes a proximity sensor with any other 1321 orientation, it MUST NOT be accessible through this API. If a device 1322 implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 1323 more.</p> 1324 1325 <a name="section-7.4"></a><h3>7.4. Data Connectivity</h3> 1326 <p>Network connectivity and access to the Internet are vital features of 1327 Android. Meanwhile, device-to-device interaction adds significant value to 1328 Android devices and applications. Device implementations MUST meet the 1329 data connectivity requirements in this section.</p> 1330 <a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4> 1331 <p>"Telephony" as used by the Android 2.3 APIs and this document refers 1332 specifically to hardware related to placing voice calls and sending SMS 1333 messages via a GSM or CDMA network. While these voice calls may or may not be 1334 packet-switched, they are for the purposes of Android 2.3 considered 1335 independent of any data connectivity that may be implemented using the same 1336 network. In other words, the Android "telephony" functionality and APIs refer 1337 specifically to voice calls and SMS; for instance, device implementations that 1338 cannot place calls or send/receive SMS messages MUST NOT report the 1339 "android.hardware.telephony" feature or any sub-features, regardless of 1340 whether they use a cellular network for data connectivity.</p> 1341 <p>Android 2.3 MAY be used on devices that do not include telephony hardware. 1342 That is, Android 2.3 is compatible with devices that are not phones. 1343 However, if a device implementation does include GSM or CDMA telephony, it 1344 MUST implement full support for the API for that technology. Device 1345 implementations that do not include telephony hardware MUST implement the full 1346 APIs as no-ops.</p> 1347 <a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4> 1348 <p>Android 2.3 device implementations SHOULD include support for one or more 1349 forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 1350 support for 802.11, it MUST implement the corresponding Android API.</p> 1351 <a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4> 1352 <p>Device implementations SHOULD include a Bluetooth transceiver. Device 1353 implementations that do include a Bluetooth transceiver MUST enable the 1354 RFCOMM-based Bluetooth API as described in the SDK documentation [<a 1355 href="#resources32">Resources, 32</a>]. Device implementations SHOULD 1356 implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 1357 appropriate for the device.</p> 1358 <p>The Compatibility Test Suite includes cases that cover basic operation of 1359 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 1360 protocol between devices, it cannot be fully tested by unit tests running on a 1361 single device. Consequently, device implementations MUST also pass the 1362 human-driven Bluetooth test procedure described in Appendix A.</p> 1363 <a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4> 1364 <p>Device implementations SHOULD include a transceiver and related hardware 1365 for Near-Field Communications (NFC). If a device implementation does include 1366 NFC hardware, then it:</p> 1367 <ul> 1368 <li>MUST report the android.hardware.nfc feature from the 1369 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. [<a href="#resources27">Resources, 27</a>]</li> 1370 <li>MUST be capable of reading and writing NDEF messages via the following NFC 1371 standards:<ul> 1372 <li>MUST be capable of acting as an NFC Forum reader/writer 1373 (as defined by the NFC Forum technical specification 1374 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards:<ul> 1375 <li>NfcA (ISO14443-3A)</li> 1376 <li>NfcB (ISO14443-3B) </li> 1377 <li>NfcF (JIS 6319-4)</li> 1378 <li>NfcV (ISO 15693)</li> 1379 <li>IsoDep (ISO 14443-4)</li> 1380 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 1381 </ul></li> 1382 <li>MUST be capable of transmitting and receiving data via the following 1383 peer-to-peer standards and protocols:<ul> 1384 <li>ISO 18092</li> 1385 <li>LLCP 1.0 (defined by the NFC Forum)</li> 1386 <li>SDP 1.0 (defined by the NFC Forum)</li> 1387 <li>NDEF Push Protocol [<a href="#resources33">Resources, 33</a>]</li> 1388 </ul></li> 1389 <li>MUST scan for all supported technologies while in NFC discovery mode.</li> 1390 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active.</li> 1391 </ul> 1392 <p>(Note that publicly available links are not available for the JIS, ISO, and 1393 NFC Forum specifications cited above.)</p> 1394 <p>Additionally, device implementations SHOULD support the following 1395 widely-deployed MIFARE technologies.</p> 1396 <ul> 1397 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources34">Resources, 34</a>], MF1S703x [<a href="#resources35">Resources, 35</a>])</li> 1398 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources36">Resources, 36</a>], MF0ICU2 [<a href="#resources37">Resources, 37</a>])</li> 1399 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources38">Resources, 38</a>], AN130411 [<a href="#resources39">Resources, 39</a>])</li> 1400 </ul> 1401 <p>Note that Android 2.3.3 includes APIs for these MIFARE types. If a 1402 device implementation supports MIFARE, it:</p> 1403 <ul> 1404 <li>MUST implement the corresponding Android APIs as documented by the 1405 Android SDK</li> 1406 <li>MUST report the feature com.nxp.mifare from the 1407 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 1408 [<a href="#resources27">Resources, 27</a>] Note that this is not a standard 1409 Android feature, and as such does not appear as a constant on the 1410 <code>PackageManager</code> class.</li> 1411 <li>MUST NOT implement the corresponding Android APIs nor report the 1412 com.nxp.mifare feature unless it also implements general NFC support as 1413 described in this section</li> 1414 </ul> 1415 <p>If a device implementation does not include NFC hardware, it MUST NOT 1416 declare the android.hardware.nfc feature from the 1417 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 1418 href="#resources27">Resources, 27</a>], and MUST implement the Android 2.3 NFC 1419 API as a no-op.</p> 1420 <p>As the classes <code>android.nfc.NdefMessage</code> and 1421 <code>android.nfc.NdefRecord</code> represent a protocol-independent data 1422 representation format, device implementations MUST implement these APIs even 1423 if they do not include support for NFC or declare the android.hardware.nfc 1424 feature.</p> 1425 <a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4> 1426 <p>Device implementations MUST include support for one or more forms of data 1427 networking. Specifically, device implementations MUST include support for at 1428 least one data standard capable of 200Kbit/sec or greater. Examples of 1429 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 1430 Ethernet, etc.</p> 1431 <p>Device implementations where a physical networking standard (such as 1432 Ethernet) is the primary data connection SHOULD also include support for at 1433 least one common wireless data standard, such as 802.11 (WiFi).</p> 1434 <p>Devices MAY implement more than one form of data connectivity.</p> 1435 1436 1437 <a name="section-7.5"></a><h3>7.5. Cameras</h3> 1438 <p>Device implementations SHOULD include a rear-facing camera, and MAY include 1439 a front-facing camera. A rear-facing camera is a camera located on the side of 1440 the device opposite the display; that is, it images scenes on the far side of 1441 the device, like a traditional camera. A front-facing camera is a camera 1442 located on the same side of the device as the display; that is, a camera 1443 typically used to image the user, such as for video conferencing and similar 1444 applications.</p> 1445 <a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4> 1446 <p>Device implementations SHOULD include a rear-facing camera. If a device 1447 implementation includes a rear-facing camera, it:</p> 1448 <ul> 1449 <li>MUST have a resolution of at least 2 megapixels</li> 1450 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 1451 in the camera driver (transparent to application software)</li> 1452 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 1453 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 1454 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 1455 registered on a Camera preview surface, unless the application has explicitly 1456 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 1457 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 1458 object. Note that this constraint does not apply to the device's built-in 1459 system camera application, but only to third-party applications using 1460 <code>Camera.PreviewCallback</code>.</li> 1461 </ul> 1462 <a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4> 1463 <p>Device implementations MAY include a front-facing camera. If a device 1464 implementation includes a front-facing camera, it:</p> 1465 <ul> 1466 <li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 1467 <li>MUST NOT use a front-facing camera as the default for the Camera API. 1468 That is, the camera API in Android 2.3 has specific support for front-facing 1469 cameras, and device implementations MUST NOT configure the API to to treat a 1470 front-facing camera as the default rear-facing camera, even if it is the only 1471 camera on the device.</li> 1472 <li>MAY include features (such as auto-focus, flash, etc.) 1473 available to rear-facing cameras as described in Section 7.5.1.</li> 1474 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 1475 CameraPreview, as follows:</li> 1476 <ul> 1477 <li>If the device implementation is capable of being rotated by user (such as 1478 automatically via an accelerometer or manually via user input), the camera 1479 preview MUST be mirrored horizontally relative to the device's current 1480 orientation.</li> 1481 <li>If the current application has explicitly requested that the Camera 1482 display be rotated via a call to the 1483 <code>android.hardware.Camera.setDisplayOrientation()</code> [<a 1484 href="#resources40">Resources, 40</a>] method, the camera preview MUST be 1485 mirrored horizontally relative to the orientation specified by the 1486 application.</li> 1487 <li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 1488 </ul> 1489 <li>MUST mirror the image data returned to any "postview" camera callback 1490 handlers, in the same manner as the camera preview image stream. (If the device 1491 implementation does not support postview callbacks, this requirement obviously 1492 does not apply.)</li> 1493 <li>MUST NOT mirror the final captured still image or video streams returned 1494 to application callbacks or committed to media storage</li> 1495 </ul> 1496 <a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4> 1497 <p>Device implementations MUST implement the following behaviors for the 1498 camera-related APIs, for both front- and rear-facing cameras:</p> 1499 <ol> 1500 <li>If an application has never called 1501 android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 1502 use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 1503 application callbacks.</li> 1504 <li>If an application registers an android.hardware.Camera.PreviewCallback 1505 instance and the system calls the onPreviewFrame() method when the preview 1506 format is YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() 1507 must further be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 1508 <li>Device implementations SHOULD support the YV12 format (as denoted by the 1509 <code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 1510 for both front- and rear-facing cameras. Note that the Compatibility 1511 Definition for a future version is planned to change this requirement to 1512 "MUST". That is, YV12 support is optional in Android 2.3 but <b>will be 1513 required</b> by a future version. Existing and new devices that run Android 1514 2.3 are <b>very strongly encouraged to meet this requirement in Android 1515 2.3</b>, or they will not be able to attain Android compatibility when 1516 upgraded to the future version.</li> 1517 </ol> 1518 <p>Device implementations MUST implement the full Camera API included in the 1519 Android 2.3 SDK documentation [<a href="#resources41">Resources, 41</a>]), 1520 regardless of whether the device includes hardware autofocus or other 1521 capabilities. For instance, cameras that lack autofocus MUST still call any 1522 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 1523 this has no relevance to a non-autofocus camera.) Note that this does apply 1524 to front-facing cameras; for instance, even though most front-facing cameras 1525 do not support autofocus, the API callbacks must still be "faked" as 1526 described.</p> 1527 <p>Device implementations MUST recognize and honor each parameter name defined 1528 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 1529 underlying hardware supports the feature. If the device hardware does not 1530 support a feature, the API must behave as documented. Conversely, Device 1531 implementations MUST NOT honor or recognize string constants passed 1532 to the <code>android.hardware.Camera.setParameters()</code> method other than 1533 those documented as constants on the 1534 <code>android.hardware.Camera.Parameters</code>. That is, 1535 device implementations MUST support all standard Camera parameters if the 1536 hardware allows, and MUST NOT support custom Camera parameter types.</p> 1537 <a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4> 1538 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that 1539 the long dimension of the camera aligns with the screen's long dimention. That 1540 is, when the device is held in the landscape orientation, a cameras MUST 1541 capture images in the landscape orientation. This applies regardless of the 1542 device's natural orientation; that is, it applies to landscape-primary devices 1543 as well as portrait-primary devices.</p> 1544 1545 1546 <a name="section-7.6"></a><h3>7.6. Memory and Storage</h3> 1547 <p>The fundamental function of Android 2.3 is to run applications. Device 1548 implementations MUST the requirements of this section, to ensure adequate 1549 storage and memory for applications to run properly.</p> 1550 <a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4> 1551 <p>Device implementations MUST have at least 128MB of memory available to the 1552 kernel and userspace. The 128MB MUST be in addition to any memory dedicated to 1553 hardware components such as radio, memory, and so on that is not under the 1554 kernel's control.</p> 1555 <p>Device implementations MUST have at least 150MB of non-volatile storage 1556 available for user data. That is, the <code>/data</code> partition MUST be at 1557 least 150MB.</p> 1558 <p>Beyond the requirements above, device implementations SHOULD have at least 1559 1GB of non-volatile storage available for user data. Note that this higher 1560 requirement is planned to become a hard minimum in a future version of 1561 Android. Device implementations are strongly encouraged to meet these 1562 requirements now, or else they may not be eligible for compatibility for a 1563 future version of Android.</p> 1564 <p>The Android APIs include a Download Manager that applications may use to 1565 download data files. The Download Manager implementation MUST be capable of 1566 downloading individual files 55MB in size, or larger. The Download Manager 1567 implementation SHOULD be capable of downloading files 100MB in size, or 1568 larger.</p> 1569 <a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4> 1570 <p>Device implementations MUST offer shared storage for applications. The 1571 shared storage provided MUST be at least 1GB in size.</p> 1572 <p>Device implementations MUST be configured with shared storage mounted by 1573 default, "out of the box". If the shared storage is not mounted on the Linux 1574 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 1575 from <code>/sdcard</code> to the actual mount point.</p> 1576 <p>Device implementations MUST enforce as documented the 1577 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 1578 shared storage. Shared storage MUST otherwise be writable by any application 1579 that obtains that permission.</p> 1580 <p>Device implementations MAY have hardware for user-accessible removable 1581 storage, such as a Secure Digital card. Alternatively, device implementations 1582 MAY allocate internal (non-removable) storage as shared storage for apps.</p> 1583 <p>Regardless of the form of shared storage used, device implementations MUST 1584 provide some mechanism to access the contents of shared storage from a host 1585 computer, such as USB mass storage or Media Transfer Protocol.</p> 1586 <p>It is illustrative to consider two common examples. If a device 1587 implementation includes an SD card slot to satisfy the shared storage 1588 requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 1589 with the device as sold to users, and MUST be mounted by default. 1590 Alternatively, if a device implementation uses internal fixed storage to 1591 satisfy this requirement, that storage MUST be 1GB in size or larger 1592 and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 1593 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 1594 <p>Device implementations that include multiple shared storage paths (such as 1595 both an SD card slot and shared internal storage) SHOULD modify the core 1596 applications such as the media scanner and ContentProvider to transparently 1597 support files placed in both locations.</p> 1598 1599 <a name="section-7.7"></a><h3>7.7. USB</h3> 1600 <p>Device implementations:</p> 1601 <ul> 1602 <li>MUST implement a USB client, connectable to a USB host with a standard 1603 USB-A port</li> 1604 <li>MUST implement the Android Debug Bridge over USB (as described in Section 1605 7)</li> 1606 <li>MUST implement the USB mass storage specification, to allow a host 1607 connected to the device to access the contents of the /sdcard volume </li> 1608 <li>SHOULD use the micro USB form factor on the device side</li> 1609 <li>MAY include a non-standard port on the device side, but if so MUST ship 1610 with a cable capable of connecting the custom pinout to standard USB-A 1611 port</li> 1612 </ul> 1613 1614 1615 <a name="section-8"></a><h2>8. Performance Compatibility</h2> 1616 <p>Compatible implementations must ensure not only that applications simply 1617 run correctly on the device, but that they do so with reasonable performance 1618 and overall good user experience. Device implementations MUST meet the key 1619 performance metrics of an Android 2.3 compatible device defined in the table 1620 below:</p> 1621 <table><tbody><tr> 1622 <td><b>Metric</b></td> 1623 <td><b>Performance Threshold</b></td> 1624 <td><b>Comments</b></td> 1625 </tr> 1626 <tr> 1627 <td>Application Launch Time</td> 1628 <td>The following applications should launch within the specified time.<ul> 1629 <li>Browser: less than 1300ms</li> 1630 <li>MMS/SMS: less than 700ms</li> 1631 <li>AlarmClock: less than 650ms</li> 1632 </ul></td> 1633 <td>The launch time is measured as the total time to 1634 complete loading the default activity for the application, including the time 1635 it takes to start the Linux process, load the Android package into the Dalvik 1636 VM, and call onCreate.</td> 1637 </tr> 1638 <tr> 1639 <td>Simultaneous Applications</td> 1640 <td>When multiple applications have been launched, re-launching an 1641 already-running application after it has been launched must take less than the 1642 original launch time.</td> 1643 <td> </td> 1644 </tr> 1645 </tbody> 1646 </table> 1647 1648 <a name="section-9"></a><h2>9. Security Model Compatibility</h2> 1649 <p>Device implementations MUST implement a security model consistent with the 1650 Android platform security model as defined in Security and Permissions 1651 reference document in the APIs [<a href="#resources42">Resources, 42</a>] in the 1652 Android developer documentation. Device implementations MUST support 1653 installation of self-signed applications without requiring any additional 1654 permissions/certificates from any third parties/authorities. Specifically, 1655 compatible devices MUST support the security mechanisms described in the 1656 follow sub-sections.</p> 1657 <a name="section-9.1"></a><h3>9.1. Permissions</h3> 1658 <p>Device implementations MUST support the Android permissions model as 1659 defined in the Android developer documentation [<a 1660 href="#resources42">Resources, 42</a>]. Specifically, 1661 implementations MUST enforce each permission defined as described in the SDK 1662 documentation; no permissions may be omitted, altered, or ignored. 1663 Implementations MAY add additional permissions, provided the new permission ID 1664 strings are not in the android.* namespace.</p> 1665 <a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3> 1666 <p>Device implementations MUST support the Android application sandbox model, 1667 in which each application runs as a unique Unix-style UID and in a separate 1668 process. Device implementations MUST support running multiple applications as 1669 the same Linux user ID, provided that the applications are properly signed and 1670 constructed, as defined in the Security and Permissions reference [<a 1671 href="#resources42">Resources, 42</a>].</p> 1672 <a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3> 1673 <p>Device implementations MUST support the Android file access permissions 1674 model as defined in as defined in the Security and Permissions reference [<a 1675 href="#resources42">Resources, 42</a>].</p> 1676 <a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3> 1677 <p>Device implementations MAY include runtime environments that execute 1678 applications using some other software or technology than the Dalvik virtual 1679 machine or native code. However, such alternate execution environments MUST 1680 NOT compromise the Android security model or the security of installed Android 1681 applications, as described in this section.</p> 1682 <p>Alternate runtimes MUST themselves be Android applications, and abide by 1683 the standard Android security model, as described elsewhere in Section 9.</p> 1684 <p>Alternate runtimes MUST NOT be granted access to resources protected by 1685 permissions not requested in the runtime's AndroidManifest.xml file via the 1686 <code><uses-permission></code> mechanism.</p> 1687 <p>Alternate runtimes MUST NOT permit applications to make use of features 1688 protected by Android permissions restricted to system applications.</p> 1689 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 1690 <ul> 1691 <li>Alternate runtimes SHOULD install apps via the PackageManager into 1692 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 1693 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 1694 applications using the alternate runtime.</li> 1695 <li>Alternate runtimes and installed applications using an alternate runtime 1696 MUST NOT reuse the sandbox of any other app installed on the device, except 1697 through the standard Android mechanisms of shared user ID and signing 1698 certificate</li> 1699 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 1700 the sandboxes corresponding to other Android applications.</li> 1701 </ul> 1702 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 1703 applications any privileges of the superuser (root), or of any other user ID.</p> 1704 <p>The .apk files of alternate runtimes MAY be included in the system image of 1705 a device implementation, but MUST be signed with a key distinct 1706 from the key used to sign other applications included with the device 1707 implementation.</p> 1708 <p>When installing applications, alternate runtimes MUST obtain user consent 1709 for the Android permissions used by the application. That is, if an 1710 application needs to make use of a device resource for which there is a 1711 corresponding Android permission (such as Camera, GPS, etc.), the alternate 1712 runtime MUST inform the user that the application will be able to access 1713 that resource. If the runtime environment does not record application 1714 capabilities in this manner, the runtime environment MUST list all 1715 permissions held by the runtime itself when installing any application 1716 using that runtime.</p> 1717 1718 <a name="section-10"></a><h2>10. Software Compatibility Testing</h2> 1719 <p>The Android Open-Source Project includes various testing tools to verify 1720 that device implementations are compatible. Device implementations MUST pass 1721 all tests described in this section.</p> 1722 <p>However, note that no software test package is fully comprehensive. For 1723 this reason, device implementers are very strongly encouraged to make the 1724 minimum number of changes as possible to the reference and preferred 1725 implementation of Android 2.3 available from the Android Open-Source Project. 1726 This will minimize the risk of introducing bugs that create incompatibilities 1727 requiring rework and potential device updates.</p> 1728 <a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3> 1729 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 1730 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 1731 Project, using the final shipping software on the device. Additionally, device 1732 implementers SHOULD use the reference implementation in the Android Open 1733 Source tree as much as possible, and MUST ensure compatibility in cases of 1734 ambiguity in CTS and for any reimplementations of parts of the reference 1735 source code.</p> 1736 <p>The CTS is designed to be run on an actual device. Like any software, the 1737 CTS may itself contain bugs. The CTS will be versioned independently of this 1738 Compatibility Definition, and multiple revisions of the CTS may be released 1739 for Android 2.3. Device implementations MUST pass the latest CTS version 1740 available at the time the device software is completed.</p> 1741 <p>MUST pass the most recent version of the Android Compatibility Test Suite 1742 (CTS) available at the time of the device implementation's software is 1743 completed. (The CTS is available as part of the Android Open Source Project [<a 1744 href="#resources02">Resources, 2</a>].) The CTS tests many, but not all, of the 1745 components outlined in this document.</p> 1746 <a name="section-10.2"></a><h3>10.2. CTS Verifier</h3> 1747 <p>Device implementations MUST correctly execute all applicable cases in the 1748 CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 1749 and is intended to be run by a human operator to test functionality that 1750 cannot be tested by an automated system, such as correct functioning of a 1751 camera and sensors.</p> 1752 <p>The CTS Verifier has tests for many kinds of hardware, including some 1753 hardware that is optional. Device implementations MUST pass all tests for 1754 hardware which they possess; for instance, if a device possesses an 1755 accelerometer, it MUST correctly execute the Accelerometer test case in the 1756 CTS Verifier. Test cases for features noted as optional by this Compatibility 1757 Definition Document MAY be skipped or omitted.</p> 1758 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 1759 above. However, since many builds are very similar, device implementers are 1760 not expected to explicitly run the CTS Verifier on builds that differ only in 1761 trivial ways. Specifically, device implementations that differ from an 1762 implementation that has passed the CTS Verfier only by the set of included 1763 locales, branding, etc. MAY omit the CTS Verifier test.</p> 1764 <a name="section-10.3"></a><h3>10.3. Reference Applications</h3> 1765 <p>Device implementers MUST test implementation compatibility using the 1766 following open-source applications:</p> 1767 <ul> 1768 <li>The "Apps for Android" applications [<a href="#resources43">Resources, 43</a>].</li> 1769 <li>Replica Island (available in Android Market; only required for device 1770 implementations that support with OpenGL ES 2.0)</li> 1771 </ul> 1772 <p>Each app above MUST launch and behave correctly on the implementation, for 1773 the implementation to be considered compatible.</p> 1774 1775 1776 <a name="section-11"></a><h2>11. Updatable Software</h2> 1777 <p>Device implementations MUST include a mechanism to replace the entirety of 1778 the system software. The mechanism need not perform "live" upgrades -- that 1779 is, a device restart MAY be required.</p> 1780 <p>Any method can be used, provided that it can replace the entirety of the 1781 software preinstalled on the device. For instance, any of the following 1782 approaches will satisfy this requirement:</p> 1783 <ul> 1784 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 1785 <li>"Tethered" updates over USB from a host PC</li> 1786 <li>"Offline" updates via a reboot and update from a file on removable 1787 storage</li> 1788 </ul> 1789 <p>The update mechanism used MUST support updates without wiping user data. 1790 Note that the upstream Android software includes an update mechanism that 1791 satisfies this requirement.</p> 1792 <p>If an error is found in a device implementation after it has been released 1793 but within its reasonable product lifetime that is determined in consultation 1794 with the Android Compatibility Team to affect the compatibility of third-party 1795 applications, the device implementer MUST correct the error via a software 1796 update available that can be applied per the mechanism just described.</p> 1797 1798 <a name="section-12"></a><h2>12. Contact Us</h2> 1799 <p>You can contact the document authors at <a 1800 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 1801 clarifications and to bring up any issues that you think the document does not 1802 cover.</p> 1803 1804 <div style="page-break-before: always;"></div> 1805 1806 <a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2> 1807 <p>The Compatibility Test Suite includes cases that cover basic operation of 1808 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 1809 protocol between devices, it cannot be fully tested by unit tests running on a 1810 single device. Consequently, device implementations MUST also pass the 1811 human-operated Bluetooth test procedure described below.</p> 1812 <p>The test procedure is based on the BluetoothChat sample app included in the 1813 Android open-source project tree. The procedure requires two devices:</p> 1814 <ul> 1815 <li>a candidate device implementation running the software build to be tested</li> 1816 <li>a separate device implementation already known to be compatible, and of a 1817 model from the device implementation being tested -- that is, a "known 1818 good" device implementation</li> 1819 </ul> 1820 <p>The test procedure below refers to these devices as the "candidate" and "known 1821 good" devices, respectively.</p> 1822 <h3>Setup and Installation</h3> 1823 <ol> 1824 <li>Build BluetoothChat.apk via 'make samples' from an Android source code tree.</li> 1825 <li>Install BluetoothChat.apk on the known-good device.</li> 1826 <li>Install BluetoothChat.apk on the candidate device.</li> 1827 </ol> 1828 <h3>Test Bluetooth Control by Apps</h3> 1829 <ol> 1830 <li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled.</li> 1831 <li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth.</li> 1832 </ol> 1833 <h3>Test Pairing and Communication</h3> 1834 <ol> 1835 <li>Launch the Bluetooth Chat app on both devices.</li> 1836 <li>Make the known-good device discoverable from within BluetoothChat (using the Menu).</li> 1837 <li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device.</li> 1838 <li>Send 10 or more messages from each device, and verify that the other device receives them correctly.</li> 1839 <li>Close the BluetoothChat app on both devices by pressing <b>Home</b>.</li> 1840 <li>Unpair each device from the other, using the device Settings app.</li> 1841 </ol> 1842 <h3>Test Pairing and Communication in the Reverse Direction</h3> 1843 <ol> 1844 <li>Launch the Bluetooth Chat app on both devices.</li> 1845 <li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li> 1846 <li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li> 1847 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 1848 <li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li> 1849 </ol> 1850 <h3>Test Re-Launches</h3> 1851 <ol> 1852 <li>Re-launch the Bluetooth Chat app on both devices.</li> 1853 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 1854 </ol> 1855 <p>Note: the above tests have some cases which end a test section by using 1856 Home, and some using Back. These tests are not redundant and are not optional: 1857 the objective is to verify that the Bluetooth API and stack works correctly 1858 both when Activities are explicitly terminated (via the user pressing Back, 1859 which calls finish()), and implicitly sent to background (via the user 1860 pressing Home.) Each test sequence MUST be performed as described.</p> 1861 <div id="footerContent"> 1862 </div> 1863 </body> 1864 </html> 1865
