Gavare's eXperimental Emulator (formerly known as mips64emul) is a

computer architecture In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, t ...

emulator In computing, an emulator is Computer hardware, hardware or software that enables one computer system (called the ''host'') to behave like another computer system (called the ''guest''). An emulator typically enables the host system to run so ...

being developed by Anders Gavare. It is available as

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

under a revised

BSD-style license BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...

. In 2005, Gavare changed the name of the software project from mips64emul to GXemul. This was to avoid giving the impression that the emulator was confined to the

MIPS architecture MIPS (Microprocessor without Interlocked Pipelined Stages) is a family of reduced instruction set computer (RISC) instruction set architectures (ISA)Price, Charles (September 1995). ''MIPS IV Instruction Set'' (Revision 3.2), MIPS Technologies, ...

, which was the only architecture being emulated initially. Although development of the emulator is still a work-in-progress, since 2004 it has been stable enough to let various unmodified guest

operating systems An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also inc ...

run as if they were running on real hardware. Currently emulated processor architectures include

ARM In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

, MIPS, M88K,

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

, and

SuperH SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems. At t ...

. Guest operating systems that have been verified to work inside the emulator are

NetBSD NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is a ...

OpenBSD OpenBSD is a security-focused, free and open-source, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by forking NetBSD 1.0. According to the website, the OpenBSD project em ...

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

HelenOS HelenOS is an operating system based on a multiserver microkernel design. The source code of HelenOS is written in C and published under the BSD-3-Clause license. The system is described as a “research development open-source operating syste ...

Ultrix Ultrix (officially all-caps ULTRIX) is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations. History The initial development of Unix occurred on DEC equip ...

, and Sprite. Apart from running entire guest operating systems, the emulator can also be used for experiments on a smaller scale, such as hobby operating system development, or it can be used as a general

debugger A debugger or debugging tool is a computer program used to software testing, test and debugging, debug other programs (the "target" program). The main use of a debugger is to run the target program under controlled conditions that permit the pr ...

Dynamic translation

GXemul's processor emulation uses

dynamic translation In computer science, dynamic recompilation is a feature of some emulators and virtual machines, where the system may recompile some part of a program during execution. By compiling during execution, the system can tailor the generated code to ...

, to convert the emulated processor's instructions into an

intermediate representation An intermediate representation (IR) is the data structure or code used internally by a compiler or virtual machine to represent source code. An IR is designed to be conducive to further processing, such as optimization and translation. A "good" ...

(IR). The IR is in a format which can be executed by the host. In other words, it should be possible to port the emulator to new host architectures with just a recompilation; there is no need to implement a native code generation backend for each host architecture to get it running.

External links

The GXemul homepage

Free emulation software Multi-emulators PowerPC emulators

Dynamic translation

See also

External links