GUSS the Universal System Simulator

Table of contents

• Introduction
• News
• Status
• Download
• Documentation
• Contact us
• Links

Introduction

GUSS the Universal System Simulator simulates hardware to test, debug and profile software on. It is (or will) capable of running an operating system without any modification to the OS itself.

This project has regretfully been decommissioned; contact maintainers at gnu.org if you are interested in resurrecting it.

GUSS has several objectives:

• Be fast. Performance is important.
• Support complex memory hierarchives, with minimal performance loss.
• Simulate multiple processors, including interprocess interrupts, message passing and such.
• Run system-level code to allow studies of the interaction of operating system, user program, and architecture.
• Gather statistics, such as memory usage, frequency of important events, and instruction profiling.
• Make it possible to extend and configure the simulator using a scripting language (Scheme).
• Allow symboling debuggers as frontends.
• Be determenistic to allow repeats of both statistics gathering and debugging.
• Be as host-independent as possible.

News

Mon Sep 15 2003 - Performance is everything.

I (Johan Rydberg) have spent the last couple of months rewriting the simulator engine of GUSS. The new engine will increase the performance of GUSS by several times.

Status

GUSS currently only has one (partial) functional target: i386. This target simulates your standard x86 personal computer. The target has yet to boot GNU/Linux, but it has successfully booted L4ka+sigma0+pingpong (proof).

Work has begun on some other targets, or there are plans for:

• IA-64 (work has begun)
• MIPS32 (planned -- back-ported from old GUSS)
• PowerPC (work has begun)
• ARM (planned)
• Motorola 68K (planned)

Download

Everything old is out. To get GUSS, use the CVS repository:

  cvs -d:pserver:anoncvs@subversions.gnu.org:/cvsroot/guss login 
  {just hit enter when prompted for password}
  cvs -z3 -d:pserver:anoncvs@subversions.gnu.org:/cvsroot/guss co guss

Documentation

Not yet available. You're free to help.

Contact us

There are some public mailing lists related to GUSS.

guss-hackers (archives)

For discussing GUSS issues

guss-commit (archives)

A read-only mailing list containing the notes from checkins to the GUSS CVS repository

Links

Here are some useful resources:

• SimOS is a complete machine simulation environment designed for the efficient and accurate study of both uniprocessor and multiprocessor computer systems. SimOS simulates computer hardware in enough detail to boot and run commercial operating systems.
• QEMU. QEMU is an x86 processor emulator. Its purpose is to run x86 Linux processes on non-x86 Linux architectures such as PowerPC or ARM. By using dynamic translation it achieves a reasonnable speed while being easy to port on new host CPUs. An obviously interesting x86 only process is Wine (Windows emulation).
• bintrans - The bintrans Dynamic Binary Translator.
• Bochs - A full system emulator for the IA-32 architecture.