xv6 is a re-implementation of Dennis Ritchie's and Ken Thompson's Unix Version 6 (v6). xv6 loosely follows the structure and style of v6, but is implemented for a modern RISC-V multiprocessor using ANSI C.

ACKNOWLEDGMENTS

xv6 is inspired by John Lions's Commentary on UNIX 6th Edition (Peer to Peer Communications; ISBN: 1-57398-013-7; 1st edition (June 14, 2000)). See also https://pdos.csail.mit.edu/6.1810/, which provides pointers to on-line resources for v6.

The following people have made contributions: Russ Cox (context switching, locking), Cliff Frey (MP), Xiao Yu (MP), Nickolai Zeldovich, and Austin Clements.

We are also grateful for the bug reports and patches contributed by Takahiro Aoyagi, Marcelo Arroyo, Silas Boyd-Wickizer, Anton Burtsev, carlclone, Ian Chen, Dan Cross, Cody Cutler, Mike CAT, Tej Chajed, Asami Doi, Wenyang Duan, eyalz800, Nelson Elhage, Saar Ettinger, Alice Ferrazzi, Nathaniel Filardo, flespark, Peter Froehlich, Yakir Goaron, Shivam Handa, Matt Harvey, Bryan Henry, jaichenhengjie, Jim Huang, Matúš Jókay, John Jolly, Alexander Kapshuk, Anders Kaseorg, kehao95, Wolfgang Keller, Jungwoo Kim, Jonathan Kimmitt, Eddie Kohler, Vadim Kolontsov, Austin Liew, l0stman, Pavan Maddamsetti, Imbar Marinescu, Yandong Mao, Matan Shabtay, Hitoshi Mitake, Carmi Merimovich, Mark Morrissey, mtasm, Joel Nider, Hayato Ohhashi, OptimisticSide, phosphagos, Harry Porter, Greg Price, RayAndrew, Jude Rich, segfault, Ayan Shafqat, Eldar Sehayek, Yongming Shen, Fumiya Shigemitsu, snoire, Taojie, Cam Tenny, tyfkda, Warren Toomey, Stephen Tu, Alissa Tung, Rafael Ubal, Amane Uehara, Pablo Ventura, Xi Wang, WaheedHafez, Keiichi Watanabe, Lucas Wolf, Nicolas Wolovick, wxdao, Grant Wu, x653, Jindong Zhang, Icenowy Zheng, ZhUyU1997, and Zou Chang Wei.

ERROR REPORTS

Please send errors and suggestions to Frans Kaashoek and Robert Morris (kaashoek, rtm@mit.edu). The main purpose of xv6 is as a teaching operating system for MIT's 6.1810, so we are more interested in simplifications and clarifications than new features.

BUILDING AND RUNNING XV6

You will need a RISC-V "newlib" tool chain from https://github.com/riscv/riscv-gnu-toolchain, and qemu compiled for riscv64-softmmu. Once they are installed, and in your shell search path, you can run:

make qemu

XV6-SHELL

Custom Unix-style shell implementation in xv6 supporting command execution,
pipes, and process management using C.

This project implements a custom Unix-style shell in the xv6 operating
system as part of an Operating Systems coursework project.

The shell parses and executes user commands, supporting features such as
command execution, pipelines, and process management. It interacts
directly with the xv6 kernel using system calls like fork(), exec(),
and wait() to create and manage processes.

FEATURES

• Command parsing and execution
• Support for command pipelines (|)
• Process creation using fork()
• Program execution using exec()
• Parent-child process synchronization using wait()

TECHNOLOGIES

• C
• xv6 Operating System
• Unix system calls
• Linux development environment

LEARNING OUTCOMES

This project demonstrates practical understanding of:

• Unix process management
• Inter-process communication using pipes
• Shell command parsing
• Low-level systems programming in C