• Dalvik Linux
• Dalvik Vm

I know you are little excited go to further into android, but before enter into the world of android there are some basic concepts which you should understand starting from Dalvik Virtual Machine

• Dalvik is the virtual machine that powers the Java platform on Android-based phones. Alien Dalvik will enable the majority of. This will allow app owners in the Android Market to simply repackage Android Package (APK) files for users running Alien Davik for download. The Alien Dalvik apps will appear as.
• Seamless replacement for the standard Dalvik Virtual Machine, the engine powering Android applications; Increases the execution speed of applications developed using the Java programming language by up to five times; Advanced optimization techniques inherited from Myriad's Java virtual machine expertise.

Dalvik Virtual Machine

As its name suggests that it’s a virtual machine not hardware based machine. This is Software which helps to execute java byte code written for Android Application in Java Programming Language. It is middleware Software between java byte and executable file. It is almost same as JVM (Java Virtual Machine) but has some differences in architecture and working efficiency . Following are the steps converting a java file into dex file

Step 1:- We have some source code written in java. Source file with .java Extension for example (task.java)

Nov 28, 2013. This slide is an introduction to Android Dalvik Virtual Machine on a short course. We use two hand-made JVM and DVM which called Simple JVM and Simple DVM re.

Step 2:- Then this .java file will be compiled and converted into object code with file extension .class for example (task. Class)

Step 3:- Then this .class file will be translated into .dex file by the Dalvik Virtual Machine dex stands for Dalvik Executable.

Now the little bit about the Architecture of Dalvik Virtual Machine .
Dalvik Virtual Machine is based on Registers, because registers take less memory to run and it is designed as because we have to run Multiple Virtual Machines at the same time. It requires fewer instructions to complete the execution. While JVM is stack based it requires more memory and instructions to complete the Execution.
DVM is Register based which is designed to run on low memory, uses its own byte code and runs .dex file.
JVM is Stack based which uses java byte code and runs .class file having JIT.

.apk file Extention

.apk file is an installer package file which install on google’s Operating System Called Android. Apk stands for Android Application Package. It can also be run on certain other operating systems like Blackberry Version 10.2.1 or higher than this version.

Dalvik Linux

.apk package file contain the following directories:-

META-INF directory:

MANIFEST.MF: the Manifest file

CERT.RSA: The certificate of the application.

CERT.SF: The list of resources and SHA-1 digest of the corresponding lines in the MANIFEST.MF file;

LIB: the directory containing the compiled code that is specific to a software layer of a processor, the directory is split into more directories within it:

ARMEABI: compiled code for all ARM based processors only

ARMEABI-V7A: compiled code for all ARMv7 and above based processors only

X86: compiled code for x86 processors only

MIPS: compiled code for MIPS processors only

RES: the directory containing resources not compiled into resources.arsc (see below).

ASSETS: a directory containing applications assets, which can be retrieved by AssetManager.

ANDROIDMANIFEST.XML: An additional Android manifest file, describing the name, version, access rights, referenced library files for the application. This file may be in Android binary XML that can be converted into human-readable plaintext XML with tools such as AXMLPrinter2, android-apktool, or Androguard.

CLASSES.DEX: The classes compiled in the dex file format understandable by the Dalvik virtual machine

Dalvik Vm

RESOURCES.ARSC: a file containing precompiled resources, such as binary XML