Jasmin (Java assembler) - AbsoluteAstronomy.com

Jasmin is a free

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

assembler

Assembly language

An assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...

to create class files from human readable assembler-like syntax using the Java Virtual Machine instruction sets. Jasmin is not a Java programming language compiler.

Jasmin as an assembler takes ASCII descriptions of JVM Classes, written in a simple assembler-like syntax using the Java Virtual Machine instruction set. It converts them into binary JVM Class files, suitable for loading by a Java runtime system.

Example

The traditional HelloWorld starter in Jasmin:



 .class public HelloWorld

 .super java/lang/Object



 .method public static main([Ljava/lang/String;)V

   .limit stack 2

   .limit locals 1



   getstatic      java/lang/System/out Ljava/io/PrintStream;

   ldc            "Hello World."

   invokevirtual  java/io/PrintStream/println(Ljava/lang/String;)V

   return



 .end method

Invoking

Referenced from the Readme file
Then, to run Jasmin, use:

java -jar jasmin.jar examples\HelloWorld.j [Windows]
or
java -jar jasmin.jar examples/HelloWorld.j [Unix/Mac OS X]

History

Jon Meyer and Troy Downing wrote Jasmin for their published book "Java Virtual Machine".

At the time of writing there were no known freely available assembler for the Java Virtual Machine instruction set.
The only known compilers at the time required input in Java syntax source code, and explicitly using a JVM instruction was impossible.
Therefore the authors set out to create an assembler suitable for manipulating and producing a class file to be executed on the Virtual machine.

Jasmin remains the oldest and the original Java assembler known for JVM.

Jasmin is currently located under a SourceForge Open Source project.

Java bytecode
Java bytecode
Java bytecode is the form of instructions that the Java virtual machine executes. Each bytecode opcode is one byte in length, although some require parameters, resulting in some multi-byte instructions. Not all of the possible 256 opcodes are used. 51 are reserved for future use...
the Java .class file format
Class (file format)
In the Java programming language, source files are compiled into machine-readable class files which have a .class extension. Since Java is a platform-independent language, source code is compiled into an output file known as bytecode, which it stores in a .class file. If a source file has more...
C to Java Virtual Machine compilers
ARM9E
ARM9E
ARM9 is an ARM architecture 32-bit RISC CPU family. With this design generation, ARM moved from a von Neumann architecture to a Harvard architecture with separate instruction and data buses , significantly increasing its potential speed...

, a CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

family with direct Java bytecode execution ability
Common Intermediate Language
Common Intermediate Language
Common Intermediate Language is the lowest-level human-readable programming language defined by the Common Language Infrastructure specification and is used by the .NET Framework and Mono...

(CIL), a similar bytecode specification that runs on the CLR
Common Language Runtime
The Common Language Runtime is the virtual machine component of Microsoft's .NET framework and is responsible for managing the execution of .NET programs. In a process known as just-in-time compilation, the CLR compiles the intermediate language code known as CIL into the machine instructions...

of the .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...

.
Compiler
Compiler
A compiler is a computer program that transforms source code written in a programming language into another computer language...
Disassembler
Disassembler
A disassembler is a computer program that translates machine language into assembly language—the inverse operation to that of an assembler. A disassembler differs from a decompiler, which targets a high-level language rather than an assembly language...
List of assemblers
Instruction set
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
Microassembler
Microassembler
A microassembler is a computer program that helps prepare a microprogram to control the low level operation of a computer in much the same way an assembler helps prepare higher level code for a processor. The difference is that the microprogram is usually only developed by the processor...

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Example

Invoking

History

See also

Further reading

External links