1page.title=Android Core Technologies 2@jd:body 3 4<!-- 5 Copyright 2014 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 are 30looking to modify, contribute to, or port the Android software. This is "under 31the hood" information intended for engineers.</p> 32 33<h2 id="accessory-protocol-information">Accessories</h2> 34<p>Android devices can connect to hardware accessories, such as audio docks, 35keyboards and custom hardware, through USB or Bluetooth. This document 36describes the Android Open Accessory protocol for accessory hardware builders.</p> 37<p><a href="{@docRoot}accessories/index.html">» Accessory Protocol Information</a></p> 38 39<h2 id="art-technical-information">ART</h2> 40<p>The Android runtime (ART) is the heart of Android. It's a fast, ahead-of-time 41compiled runtime with modern garbage collection designed to scale. Android applications are 42compiled to Dalvik bytecode and run with ART. This section includes 43detailed information such as the Dalvik Executable format specification, 44and design information on the runtime itself.</p> 45<p><a href="{@docRoot}devices/tech/dalvik/index.html">» ART and Dalvik Information</a></p> 46 47<h2 id="data-usage-technical-information">Data Usage</h2> 48<p>Android's data usage features allow users to understand and control how their 49device uses network data. This document is designed for systems integrators 50and mobile operators, to help explain technical details they should be aware 51of when porting Android to specific devices.</p> 52<p><a href="{@docRoot}devices/tech/datausage/index.html">» Data Usage Information</a></p> 53 54<h2 id="debugging">Debugging and Tuning</h2> 55<p>Android is a large and complex system. This section includes tips and tricks 56about debugging at the platform level.</p> 57<p><a href="{@docRoot}devices/debugtune.html">» Debugging Information</a></p> 58 59<h2 id="HAL-technical-information">HAL File Reference</h2> 60<p>Android's Hardware Abstraction Layer (HAL) provides the interface between 61software APIs and hardware drivers. This section contains the commented code 62files of the HAL.</p> 63<p><a href="{@docRoot}devices/halref/files.html">» HAL Reference</a></p> 64 65<h2 id="kernel-technical-information">Kernel</h2> 66<p>The kernel configuration settings in this document are meant to be used as a base 67for an Android kernel configuration. All devices should have the options in android-base 68configuration enabled.</p> 69<p><a href="{@docRoot}devices/tech/kernel.html">» Kernel Information</a></p> 70 71<h2 id="lowram-technical-information">Low RAM</h2> 72<p>Android supports devices with limited memory through various optimizations, 73such as improved memory management, reduced system memory, and several 74build-time and kernel configuration settings.</p> 75<p><a href="{@docRoot}devices/low-ram.html">» Low RAM Information</a></p> 76 77<h2 id="power-technical-information">Power</h2> 78<p>Battery usage statistics are tracked by the framework. This involves keeping track of 79time spent by different device components in different states.</p> 80<p><a href="{@docRoot}devices/tech/power.html">» Power Information</a></p> 81 82<h2 id="security-technical-information">Security</h2> 83<p>Android security comes with a variety of measures, including an application 84sandbox, SELinux, dm-verity, encryption, and more.</p> 85<p><a href="{@docRoot}devices/tech/security/index.html">» Security Information</a></p> 86 87<h2 id="tradefed-test-infrastructure">Trade Federation Testing Infrastructure</h2> 88<p>Trade Federation is a continuous test framework for running tests on Android devices. 89Trade Federation's modularity makes it straightforward to slot into environments with existing build, 90test, and reporting infrastructures.</p> 91<p><a href="{@docRoot}devices/tech/test_infra/tradefed/index.html">» Trade Federation Testing Infrastructure Overview</a></p> 92 93