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Nachos Introduction

Lecturer: Tei-Wei KuoTA: Ya-Su Chen, Yuan-Hao changDate: 2005/10/19

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Nachos Nachos: – Not Another Completely Heuristic Operating System

Written by Tom Anderson and his students at UC Berkeley

http://www.cs.washington.edu/homes/tom/nachos/

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Nachos 4.0 An educational OS used to

teach monolithic kernel design and implementation

do experiments

Fact: Real hardware is difficult to handle. May break if handled wrong.

Approach: Use a virtual MIPS machine Provide some basic OS elements

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Nachos 4.0

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Nachos 4.0 Simulates MIPS architecture on host system (Unix /Linux/ Windows / MacOS X ) User programs need a cross-compiler (target MIP

S) Nachos appears as a single threaded process to th

e host operating system

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Recommended Platform Redhat Linux 7.3

Install linux directly on your pc. Install linux on virtual machine.

http://www.vmware.com/ http://www.connectix.com/

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Desiginated Platform in This Class Linux in Workstation Room 217

Installation guidehttp://newslab.csie.ntu.edu.tw/course/OS2005/files/nachos/217.htm

If your project submission can’t execute on Linux in Workstation Room 217, we will consider it as fail. The Linux kernel in Workstation Room 217 is

2.4.26. Please contact the TA in Workstation Room 217 to

apply an account if you need it.

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Nachos content

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Root directoryC++ introduction to teach how to write C++

Root directory of Nachos’s source code

Building directories for different systems(Platform dependent)

File system

Nachos’s library

MIPS machine

In/Out message queues

Source code of Nachos kernel and MIPS simulatorNachos’s sample uer programs

threads

The tool to convert user programs from MIPS’s COFF into Nachos’s NOFF format

NOFF: Nachos Object File Format

User programs’ interfaces: system calls, address space, noff format.

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How does it work?(1)

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How does it work?(2)

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How does it work?(3)

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Setup the System Refer to the following document:

http://newslab.csie.ntu.edu.tw/course/OS2005/files/nachos/217.htm

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GLOBAL A source code tag system that works the same wa

y across diverse environments.

Useful for hacking a large project containing many subdirectories, many #ifdef and many main() functions.

You can download GLOBAL fromhttp://www.gnu.org/software/global/download.html

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GLOBAL (Cont.) How To Start?

http://www.gnu.org/software/global/download.html

Installation% ./configure% make% make install

gtags, htags

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GLOBAL (Cont..) gtags – Create Tag Database

% cd NachOS-4.0/% gtags

htags – Create Hypertext Files (under HTML/) for a Web-Based Interface for Global% htags –Ff

The GLOBAL for NachOS-4.0http://newslab.csie.ntu.edu.tw/course/OS2005/files/nachos/NachOS-4.0/HTML/

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How to Start Trace Codes Read interfaces in the *.h files first.

To have overview of the whole system. Then ,read the implementations in the *.cc

files. See how the executable code supports

each interface. Documentation

http://www.cs.duke.edu/~narten/110/nachos/main/main.html

http://newslab.csie.ntu.edu.tw/course/OS2005/index.php?SelectedItem=Nachos