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, Silas Boyd-Wickizer, Anton Burtsev, carlclone, Ian

Chen, Dan Cross, Cody Cutler, Mike CAT, Tej Chajed, Asami Doi,

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, Harry Porter, Greg Price, Jude

Rich, segfault, Ayan Shafqat, Eldar Sehayek, Yongming Shen, Fumiya

Shigemitsu, Cam Tenny, tyfkda, Warren Toomey, Stephen Tu, Rafael Ubal,

Amane Uehara, Pablo Ventura, Xi Wang, WaheedHafez, Keiichi Watanabe,

Nicolas Wolovick, wxdao, Grant Wu, Jindong Zhang, Icenowy Zheng,

ZhUyU1997, and Zou Chang Wei.





The code in the files that constitute xv6 is

Copyright 2006-2022 Frans Kaashoek, Robert Morris, and Russ Cox.



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".