Datasheet

4
❘
CHAPTER 1 HELLO, ANDROID
stack produced and supported by the Open Handset Alliance and designed to operate on any
handset that meets the requirements. Google has now released its first direct-to-consumer
handset, the Nexus 1, but this device remains simply one hardware implementation running
on the Android platform.
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. (
http://googleblog.blogspot.com/2007/11/
wheres-my-gphone.html)
Put simply, Android is a combination of three components:
➤ A free, open-source operating system for mobile devices
➤ An open-source development platform for creating mobile applications
➤ Devices, particularly mobile phones, that run the Android operating system and the applica-
tions created for it
More specifically, Android is made up of several necessary and dependent parts, including the
following:
➤ A hardware reference design that describes the capabilities required for a mobile device to
support the software stack.
➤ A Linux operating system kernel that provides low-level interface with the hardware, memory
management, and process control, all optimized for mobile devices.
➤ Open-source libraries for application development, including SQLite, WebKit, OpenGL, and
a media manager.
➤ A run time used to execute and host Android applications, including the Dalvik virtual
machine and the core libraries that provide Android-specific functionality. The run time is
designed to be small and efficient for use on mobile devices.
➤ An application framework that agnostically exposes system services to the application layer,
including the window manager and location manager, content providers, telephony, and
sensors.
➤ A user interface framework used to host and launch applications.
➤ Preinstalled applications shipped as part of the stack.
➤ A software development kit used to create applications, including tools, plug-ins, and docu-
mentation.
What really makes Android compelling is its open philosophy, which ensures that you can fix any defi-
ciencies in user interface or native application design by writing an extension or replacement. Android