NachOS

Normally, an operating system runs on the machine that it manages. Nachos is unusual in that the operating system runs "side-by-side" with the simulated machine.

Installation Procedure of Nachos

I'm using WSL-2 in windows 10 and using Ubuntu 20.04 focal fosa as a subsystem of windows. To install nachos follow these steps

• Install JDk
• Add gmake
• Download and extract nachos
• Add nachos to PATH
• Compile and run Nachos

Supplementary

• Running nachos from Netbeans
• Installing MIPS Cross-compiler

Install JDK

• Download the jdk 11 from: https://www.oracle.com/java/technologies/javase-jdk11-downloads.html
  JDK 15 won't work

• Extract the jdk you downloaded using this command

  tar zxvf jdk_file_name -C __folder-name___
  

• Check by going to that folder

• Set the jdk as default

    sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/ java-1.11.0-openjdk-amd64/bin/java 1800 
  
    sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/javac 1800
  

• TO test if the installation is complete or not. Type this two commands in the console

    java -version
    javac -version
  

Add gmake

gmake is make for GNU systems. To work:

sudo ln -s /usr/bin/make /usr/bin/gmake

Download and extract nachos

Download link: https://people.eecs.berkeley.edu/~kubitron/courses/cs162-F10/Nachos/nachos-java.tar.gz

Keep it somewhere.

Extract command:

gzcat nachos-java.tar.gz | tar xf -

Add nachos to PATH

Go to the nachos directory (where you extracted nachos). Then, navigate to the bin directory and copy the path. We need to add that to our PATH variable.

• sudo gedit /etc/profile
• add this line to the end: export PATH=$PATH:PATH_TO_NACHOS_BIN
• logout and login (so that these take effect)

Compile and run nachos

• cd to proj1 directory
• gmake
• Open the Makefile in nachos
• add the option '-Xlint' to the javac command
• cd to proj1 directory
• gmake
• nachos

Remember run the ```nachos``` command from the proj1 directory.Only then it'll run if you follow the other steps correctly

You should see something like this -

Congratulations! you've finished downloading and installing Nachos.

Installing Cross Compile MIPS

To run nachos os , we need a cross compiler. In order to install cross compiler you have to do this following steps

• Download the cross compiler from https://inst.eecs.berkeley.edu/~cs162/fa13/Nachos/xgcc.html (download the Fall 2013,24MB file)
• Extract the mips compile file.
• Add the unzipped directory path to ARCHDIR and PATH. To do so, open /etc/profile

sudo nano /etc/profile

• Write down these two lines:

export ARCHDIR=path_to_mips_unzipped_directory
export PATH=$PATH:$ARCHDIR

• Login and Logout

Type these two lines below and run them in Terminal

sudo ln -s /usr/lib/x86_64-linux-gnu/libmpfr.so.6 /usr/lib/x86_64-linux-gnu/libmpfr.so.4

sudo ln -s /usr/lib/x86_64-linux-gnu/libgmp.so.10 /usr/lib/x86_64-linux-gnu/libgmp.so.3

Login and Logout (close the terminal and again open it)

Go to the test folder in nachos directory and then run gmake command You should see something like this

After running this command you should see bunch of *.coff and *.c files.