Day 2 android internals a quick overview
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Android is an open source software stack that includes an operating system, middleware, and key applications for mobile devices. It uses the Linux kernel for core system services like memory management and process management. The Android runtime uses the Dalvik virtual machine. The application framework provides APIs for location services, connectivity, multimedia, sensors, and more. Developers can create Android applications using the Android SDK which provides tools and APIs to access device capabilities.
Day 2 android internals a quick overview
- 1. Android Application Development Android Internals: A Quick Overview Ahsanul Karim http://androidstream.wordpress.com
- 2. What is Android? An Open Platform for Mobile Development Google’s Andy Rubin describes Android as: The first truly open and comprehensive platform for mobile devices, all of the software to run a mobile phone but without the proprietary obstacles that have hindered mobile innovation Android is a software stack for wide range of devices including mobiles, tablets and televisions that includes an Operating System Middleware Key Applications.
- 3. The Stack
- 4. The Stack: Linux Kernel Android runs of Linux Linux provides: 1. Hardware Abstraction Layer 2. Memory Management 3. Process Management 4. Networking Users never see Linux sub- system (adb shell commands opens Linux shell we’ll see later)
- 5. The Stack: Linux Kernel Android runs of Linux Linux provides: 1. Hardware Abstraction Layer 2. Memory Management 3. Process Management 4. Networking Users never see Linux sub- system (adb shell commands opens Linux shell we’ll see later)
- 6. The Stack: Native Libraries Bionic, a super fast and small GPL-based libc library optimized for embedded use. Surface Manager for composing window manager with off- screen buffering. 2D and 3D graphics hardware support or software simulation. Media codecs offer support for major audio/video codecs SQLite database WebKit library for fast HTML rendering
- 7. The Stack: Android Runtime Dalvik VM Every Android app runs in its own process, with its own instance of the Dalvik VM. Why Dalvik VM? 1. Optimized 2. Small memory footprints 3. Register based architecture 4. Security 5. Or may be Google’s trick to avoid SUN’s lawsuit
- 8. The Stack: Application Framework Activity Manager controls the life cycle of the app Resource Manager manages everything that is not the code Location Manager figures out the location of the phone (GPS, GSM, WiFi) Notification Manager for events such as arriving messages, appointments, etc
- 9. The Stack: Applications Shipped Apps: an email client, SMS program, calendar, maps, browser, contacts etc. Third Party Apps This is where we are
- 10. What is Android SDK Provides all necessary tools to develop Android applications. This includes 1. a compiler, 2. debugger 3. a device emulator, 4. Own virtual machine to run Android programs. background processing rich user interface library OpenGL libraries access to the file system embedded SQLite database
- 11. Android SDK Features Features/APIs Connectivity+Telephony GSM, EDGE, 3G, 4G, and LTE data transfer+calls+SMS Location API APIs for GPS and Network based location detection MAP Controls Full support for map integration+controls Multimedia Full Multimedia hardware control (camera+recorder+audio+video+still images) Sensors APIs for using sensor hardware including accelerometer, compasses, barometers etc. Bluetooth & NFC Peer to peer communication C2DM Cloud to Device Messaging (Push Notification)
- 12. Android SDK Features Features/APIs Shared Data Stores Shared Data Stores, APIs for contacts, social networks, calendar and multimedia Background Services Background Services and processes Home Screen Widgets+ Live Wallpaper HTML5 Web-kit browser Localization Framework Reuse of Application component SQLite Data storage
- 13. Android Features (Cont.) Accelerometer GPS Thermal Sensor Your App + With logic to Actuate = Gyroscope Light Sensor TTS Voice Search Magnetic Sensor