Android system operating system
Android system operating system
Types of operating systemCUPCAKE (1.5) DONUT (1.6)ECLAIR(2.0,2.1)FROYO (2.2,2.2.3)GINGERBREAD (18.104.22.168.7)HONEYCOMB (3.0,3.2.6)
ICE CREAM SANDWICH (22.214.171.124.4)JELLY BEAN (4.1 , 4.3.1 )KITKAT ( 4.4 , 4.4.4, 4.4W, 4.4W.2)LOLLIPOP ( 5.0 , 5.1.1)MARSHMALLOW ( 6.0)
OHA (Open Handset Alliance)
A business alliance consisting of 47 companies to develop open standards for mobile devices
Anoperating system(OS) issystem softwarethat managescomputer hardwareandsoftwareresources and provides commonservicesforcomputer programs. The operating system is a component of thesystem softwarein a computer system.Application programsusually require an operating system to function. Time-sharingoperating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources. For hardware functions such as input and output andmemory allocation, the operating system acts as an intermediary between programs and the computer hardware,although the application code is usually executed directly by the hardware and frequently makessystem callsto an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfromcellular phonesandvideo game consolestoweb serversandsupercomputers.
EXAMPLES Examples of popular modern operating systems includeBlackBerry,BSD,iOS,Linux(Android,Chrome OS,Debian,Fedora,Gentoo,PCLinuxOS,RHEL),OS X,QNX,Steam OS,Microsoft Windows(and variantWindows Phone),andz/OS. The first seven of these examples share roots inUnix. Popular hardreal-time operating systemsincludeFreeRTOS,MicriumandVxWorks
WHAT IS AN ANDROID
Android is a software stack for mobile devices that includes an operating system, middleware and key applications.
HTC G1,Droid,TattooMotorola Droid (X)
Velocity Micro Cruz
Toshiba Android SmartBook
Cisco Android Tablet
Android S/W Stack - ApplicationAndroid provides a set of core applications:Email ClientSMS ProgramCalendarMapsBrowserContactsEtc
All applications are written using the Java language.
Android S/W Stack App Framework (Cont)Features
Android S/W Stack - LibrariesIncluding a set of C/C++ libraries used by components of the Android system
Exposed to developers through the Android application framework
Android S/W Stack - RuntimeCore LibrariesProviding most of the functionality available in the core libraries of the Java languageAPIsData StructuresUtilitiesFile AccessNetwork AccessGraphicsEtc
Android S/W Stack Runtime (Cont)
Dalvik Virtual MachineProviding environment on which every Android application runsEach Android application runs in its own process, with its own instance of the Dalvik VM.Dalvik has been written such that a device can run multiple VMs efficiently.
Register-based virtual machine
Android S/W Stack Runtime (Cont) 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:ThreadingLow-level memory management
Android S/W Stack Linux Kernel
Relying on Linux Kernel 2.6 for core system servicesMemory and Process ManagementNetwork StackDriver ModelSecurityProviding an abstraction layer between the H/W and the rest of the S/W stack