8/14/2019 Google Android Phones
1/2
All about Google Android...
On 5 November 2007 Google announced to develop jointly with 33
other members of the OpenHandset Alliance, a mobile operating
system called Android. The Android operating system is freesoftware
distributed under the Apache License 2.0.
As the first device with Android as the operating system came on
22 October 2008 under the nameof the HTC Dream T-Mobile G1 in the
U.S. on the market.Architecture
The architecture of Android is based on the Linux kernel 2.6. He
is responsible for memorymanagement, process management and network
communications. It also provides the hardwareabstraction layer for
the rest of the software and provides the device drivers for the
system.
Other important components are based on the Sun Microsystems
developed Java technology-basedvirtual machine and associated
Dalvik Android Java class libraries.
To provide programming of its own Android applications on 12
Published November 2007development system (m3 rc20a) 1448 Java
classes and 394 interfaces. Of these, 511 classes and 128interfaces
Android-specific. In the java and javax packages are 612 or 145
classes and 150 and 51interfaces. Numerically significant is the
contribution of the Apache Commons project: 128 classesand 20
interfaces. The remaining non-Google emanating class libraries
distributed over the
packages org.bluez, org.json, org.w3c.dom and org.xml.sax.
The runtime environment of Android is based on the Dalvik
virtual machine, virtual, developed byGoogle employee Dan Bornstein
machine. The Dalvik VM functionally similar to the normal JavaVM,
both of which lead from the so-called byte-code. One major
difference is the underlyingvirtual processor architecture. The
Java VM is based on a stack machine; Dalvik VM contrast, is a
register machine. By differentiating processor architecture, the
normal Java compiler compiledprograms are not suitable for the
Dalvik VM, but Google could draw on the existing Javadevelopment
tools.
Most modern compilers generate intermediate code as a stack
machine code. This intermediateallows to abstract from the
processor architecture of the target platform, part of the
programming isseparated from the concrete processor architecture.
Since the processor model of the stackingmachine is very simple, it
is usually used for the bersetzerzwischensprache. Most real
processorstoday are register machines, such as the 80x86 and the
ARM processor. Register architectures areoften more efficient,
since the CPU on its own especially fast access memory cells,
registers, has.Dalvik notes the transformation of the stack machine
code into the register machine code at compiletime already
anticipated. To this end, the tool is used dx, "dx" stands for
Dalvik cross-assembler.Checkhttp://googlephoneandroid.com/ for more
infos.Applications for the Androidplattform are invariably written
in Java, but take them in speed-criticalareas to many in C or C + +
written in native libraries. Among them are beside codecs for
media
playback, a web browser based on WebKit, a database (SQLite) and
an OpenGL based 3D graphicslibrary.
To develop your own applications for Android, you need a recent
Java SDK and also the AndroidSDK. First written in the Java source
code is compiled with a normal Java compiler, and thenadjusted by a
cross-assembler for the Dalvik VM. For this reason, in principle,
programs can be
created with any Java development environment.
The framework relies on a strong modularity. Thus, all
components of the system) are generallyequal (except the Virtual
Machine and the underlying core system and can always be replaced.
It is
http://googlephoneandroid.com/http://googlephoneandroid.com/http://googlephoneandroid.com/
8/14/2019 Google Android Phones
2/2
therefore possible, for example, create a separate application
for creating Flash, or to dial phonenumbers from and to replace the
existing application with it.Existing software
Although the project is still very young, there are already over
10,000 applications (September 8,2009). In the SDK, a Web browser
in addition, a mapping application (Google Maps), a program
for managing contacts and a set of API demonstration
applications included. Developed softwarecan be offered by the
developers on the Android Market. This platform, however - not
unlike theopen source Android system -. The access to the Android
Market is currently very limited in mostcountries is available on
handsets only freely available software, while commercial software
issubject to a few countries.Phones with Android as the operating
system
By end 2009, Google expects the world for at least 18 models of
mobile phones Android .
The first Android phone was the HTC Dream, the second android
phone was the HTC Magic. Butthere will be release many more android
phones.
At http://googlephoneandroid.com/ you can find a full list of
all android phones.
http://googlephoneandroid.com/http://googlephoneandroid.com/
