Android operating system


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Android operating system

  1. 1. androidSavalia Devang110570116054WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
  2. 2. • “Android is a software stack for mobiledevices that includes an operating system,middleware and key applications”
  3. 3. • Android uses Linux for its device drivers,memory management, process management,and networking.• The next level up contains the Android nativelibraries. They are all written in C/C++internally, but you’ll be calling them throughJava interfaces. In this layer you can find theSurface Manager, 2D and 3D graphics, Mediacodecs, the SQL database (SQLite), and a nativeweb browser engine (WebKit).• Dalvik Virtual Machine. Dalvik runs dex files,which are converted at compile time fromstandard class and jar files.Android Platform :Android Platform :
  4. 4. • Cellular networking : GSM, EDGE, 3G(hardware dependent)• LAN : Bluetooth, and Wi-Fi (hardwaredependent)• Graphics Hardware Acceleration• Camera, GPS and Compass (hardwaredependent)• Touch screen and accelerometer for motionsensingHardware which are supported :Hardware which are supported :
  5. 5. @2011 Mihail L. Sichitiu 5• A business alliance consisting of 47 companiesto develop open standards for mobile devices
  6. 6. @2011 Mihail L. Sichitiu 7• Android provides a set of core applications: Email Client SMS Program Calendar Maps Browser Contacts Etc• All applications are written using the Java language.
  7. 7. @2011 Mihail L. Sichitiu 8• FeaturesFeature RoleViewSystemUsed to build an application, including lists, grids, textboxes, buttons, and embedded web browserContentProviderEnabling applications to access data from otherapplications or to share their own dataResourceManagerProviding access to non-code resources (localized strings,graphics, and layout files)NotificationManagerEnabling all applications to display customer alerts in thestatus barActivityManagerManaging the lifecycle of applications and providinga common navigation backstack
  8. 8. @2011 Mihail L. Sichitiu 9• Including a set of C/C++ libraries used bycomponents of the Android system• Exposed to developers through the Androidapplication framework
  9. 9. @2011 Mihail L. Sichitiu 10• Dalvik Virtual Machine Providing environment on which every Androidapplication runsEach Android application runs in its own process, with itsown instance of the Dalvik VM.Dalvik has been written such that a device can runmultiple VMs efficiently. Register-based virtual machine
  10. 10. @2011 Mihail L. Sichitiu 11• Dalvik Virtual Machine (Cont) Executing the Dalvik Executable (.dex) format.dex format is optimized for minimal memory footprint.Compilation Relying on the Linux Kernel for:ThreadingLow-level memory management
  11. 11. @2011 Mihail L. Sichitiu 12 Relying on Linux Kernel 2.6 for core system services Memory and Process Management Network Stack Driver Model Security Providing an abstraction layer between the H/W and the rest of theS/W stack
  12. 12. • Application Framework• Dalvik virtual machine• Integrated (webkit) browser• 2D and 3D graphics APIs with HW• SQLite• Video and audio codecs• Bluetooth, EDGE, 3G, and WiFi• Camera, GPS, compass, and accelerometer
  13. 13. • Java• Android SDK• Eclipse IDE(optional)• Android SDK has:• Class Library• Developer Toolsdx – Dalvik Cross-Assembleraapt – Android Asset Packaging Tooladb – Android Debug Bridgeddms – Dalvik Debug Monitor Service• Emulator and System Images• Documentation and Sample CodeSoftware Development Requires :Software Development Requires :
  14. 14. • CPU typically runs 500-600 Mhz• RAM available to an App may only be a few megabytes• Disk (flash) access is very slow• Lifecycle - apps must pause/quit often, and restore to givethe illusion that they are always running• UI designo typical screen may be HVGA (320x480)o may be in portrait or landscapeo very high DPI - small text may not be readableo touch resolution is very low (~25 pixel)• Network access may be slow and (very) intermittent
  15. 15. • Ability to customize the Google Androidplatform• Wide range of mobile applications to choose.• Features like weather details, opening screen,live RSS feeds and many more.• Entertainment functionalities will be taken anotch higher by Google Android being able tooffer online real time multiplayer games. Advantages :Advantages :
  16. 16. • We can only hope that the next versions ofAndroid have overcome the actual limitationsand that the future possibilities became arealityConclusion :Conclusion :