xv6

xv6 is a modern reimplementation of Sixth Edition Unix in ANSI C for multiprocessor x86 systems. It is used for pedagogical purposes in MIT's Operating Systems Engineering (6.828) course. Unlike Linux or BSD, xv6 is simple enough to cover in a semester, yet still contains the important concepts and organization of Unix^[1]. Rather than study the original V6 code, the course uses xv6 since PDP-11 machines are not widely available and the original operating system was written in archaic pre-ANSI C^[1].

One intriguing feature of the Makefile for xv6 is the option to produce a PDF of the entire source code listing in a readable format. The entire printout is only 91 pages, including cross references^[2]. This is reminiscent of the original V6 source code, which was published in a similar form in Lions' Commentary on UNIX 6th Edition, with Source Code.

xv6 has also been used in operating systems courses at Rutgers University^[3], Yale University^[4], Johns Hopkins University^[5], Tsinghua University^[6] and the University of Wisconsin-Madison^[7].

Unofficial Extensions

Efforts are under-way to port xv6 to the ARM architecture^[8] and to extend it with virtual memory^[9] support. Other projects include new process schedulers^[10]. Many of the projects from the MIT course involved writing new functionality for the kernel as well.

References

External links

• xv6 Home page
• git://pdos.csail.mit.edu/xv6/xv6.git Source code for xv6
• Printable version of the xv6 source code
• xv6: a simple, Unix-like teaching operating system., xv6 book.
• Operating Systems Engineering (6.828)