README.md

Setting up xv6-labs-2020 Development Environment

Prerequisites

Before starting, ensure you have:

• Git installed
• A Unix-like environment (Linux, macOS, or WSL for Windows)
• At least 1GB of free disk space
• Internet connection

Required Packages

For Ubuntu/Debian:

sudo apt-get update
sudo apt-get install git build-essential gdb-multiarch qemu-system-misc gcc-riscv64-linux-gnu binutils-riscv64-linux-gnu

For macOS (using Homebrew):

brew tap riscv/riscv
brew install riscv-tools
brew install qemu

Setup Steps

1. Clone the Repository

   git clone git://g.csail.mit.edu/xv6-labs-2020
   cd xv6-labs-2020

2. Switch to the Initial Lab Branch (util)

   git checkout util

3. Test the Installation

   make qemu

   This command will:

   • Compile the xv6 operating system
   • Start QEMU emulator
   • Boot xv6

   If successful, you should see the xv6 boot sequence and a prompt that looks like this:

   xv6 kernel is booting
   
   hart 1 starting
   hart 2 starting
   init: starting sh
   $
   

4. Exit QEMU

   • Press Ctrl-a then x to exit QEMU

console        3 21 0
$ QEMU: Terminated
(base) ➜  xv6-labs-2020 git:(util) ✗

Development Tips

1. Using GDB for Debugging In one terminal:

   make qemu-gdb

   In another terminal:

   gdb kernel/kernel

2. Useful Make Commands

   make clean     # Clean build files
   make           # Build xv6
   make qemu      # Run xv6 in QEMU
   make grade     # Test your implementation (when working on labs)

3. File Organization

   • kernel/: Kernel source files
   • user/: User programs
   • Makefile: Build configuration

Working on Labs

1. Each lab has its own branch. To switch to a different lab:

   git fetch
   git checkout [lab-name]

2. Common lab branches:

   • util
   • syscall
   • pgtbl
   • traps
   • lazy
   • cow
   • thread
   • lock
   • fs
   • mmap

3. Before starting each lab, make sure to:

   git checkout [lab-name]
   make clean

Submitting Changes

1. Make your changes in the appropriate files
2. Test your implementation:

   make grade

3. Commit your changes:

   git add [modified-files]
   git commit -m "Descriptive message about changes"

Additional Resources

• MIT 6.S081 Course Website
• xv6 Book
• RISC-V Reference