1page.title=Android Core Technologies 2@jd:body 3 4<!-- 5 Copyright 2015 The Android Open Source Project 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18--> 19<div id="qv-wrapper"> 20 <div id="qv"> 21 <h2>In this document</h2> 22 <ol id="auto-toc"> 23 </ol> 24 </div> 25</div> 26 27 28<p>Welcome to the Android core technologies section of the site. Here you 29can find information on common features useful to people and organizations who 30are looking to modify, contribute to, or port the Android software. This is 31"under the hood" information intended for engineers.</p> 32 33<h2 id="art-technical-information">ART and Dalvik</h2> 34<p>The Android runtime (ART) is the heart of Android. It's a fast, ahead-of-time 35compiled runtime with modern garbage collection designed to scale. 36Android applications are compiled to Dalvik bytecode and run with ART. This 37section includes detailed information such as the Dalvik Executable format 38specification, and design information on the runtime itself.</p> 39<p><a href="{@docRoot}devices/tech/dalvik/index.html">» ART and Dalvik 40Information</a></p> 41 42<h2 id="config">Configuration</h2> 43<p>Getting the most out of Android requires tuning of the <a 44href="{@docRoot}devices/tech/config/kernel.html">kernel</a>, <a 45href="{@docRoot}devices/tech/config/renderer.html">OpenGLRenderer</a>, and 46more. See the subpages of this section for details. 47<p><a href="{@docRoot}devices/tech/config/index.html">» Configuration 48Information</a></p> 49 50<h2 id="connect">Connectivity</h2> 51<p>This section covers Android support for NFC standards (such as Felica), 52provides details on the Radio Interface Layer (RIL), describes call notification 53behavior, and gives implementation instructions for user-facing features such as 54Data Saver and phone number blocking.</p> 55<p><a href="{@docRoot}devices/tech/connect/index.html">» Connectivity 56Information</a></p> 57 58<h2 id="data-usage-technical-information">Data Usage</h2> 59<p>Android's data usage features allow users to understand and control how 60their device uses network data. This section is designed for systems 61integrators and mobile operators to help explain technical details they 62should be aware of when porting Android to specific devices.</p> 63<p><a href="{@docRoot}devices/tech/datausage/index.html">» Data Usage 64Information</a></p> 65 66<h2 id="debugging">Debugging</h2> 67<p>Android is a large and complex system. This section includes tips and tricks 68for debugging at the platform level.</p> 69<p><a href="{@docRoot}devices/tech/debug/index.html">» Debugging 70Information</a></p> 71 72<h2 id="admin-information">Device Administration</h2> 73<p>Since Android 5.0, the platform supports use cases in a corporate 74environment under the auspices of each company’s information technology (IT) 75department.</p> 76<p><a href="{@docRoot}devices/tech/admin/index.html">» Device 77administration information</a></p> 78 79<h2 id="display">Display Settings</h2> 80<p>This section covers AOSP implementation of various Android display settings 81such as do not disturb (DND) configurations and multi-window (split-screen, 82free-form, and picture-in-picture) options.</p> 83<p><a href="{@docRoot}devices/tech/display/index.html">» Display settings 84information</a></p> 85 86<h2 id="HAL-technical-information">HAL File Reference</h2> 87<p>Android's Hardware Abstraction Layer (HAL) provides the interface between 88software APIs and hardware drivers. This section contains the commented code 89files of the HAL.</p> 90<p><a href="{@docRoot}devices/halref/files.html">» HAL Reference</a></p> 91 92<h2 id="ota-technical-information">OTA Updates</h2> 93<p>Android devices in the field can receive and install over-the-air (OTA) 94updates to the system and application software. This section describes the 95structure of update packages and the tools to build them. It is intended for 96developers building OTA updates for new and released Android devices.</p> 97<p><a href="{@docRoot}devices/tech/ota/index.html">» OTA Information</a> 98</p> 99 100<h2 id="power-technical-information">Power</h2> 101<p>The framework provides battery usage statistics, keeping track of time spent 102by different device components in different states. This section covers power 103management features (such as Doze), gives instructions for accurately measuring 104device and component power (and how to determine power values), and details the 105<code>batterystats</code> command and output.</p> 106<p><a href="{@docRoot}devices/tech/power/index.html">» Power 107Information</a></p> 108 109<h2 id="tradefed-test-infrastructure">Trade Federation Testing Infrastructure 110</h2> 111<p>Trade Federation is a continuous test framework for running tests on 112Android devices. Trade Federation's modularity makes it straightforward to 113slot into environments with existing build, test, and reporting 114infrastructures.</p> 115<p><a href="{@docRoot}devices/tech/test_infra/tradefed/index.html"> 116» Trade Federation Testing Infrastructure Overview</a></p> 117