xv6 is a modern reimplementation of

Sixth Edition Unix Sixth Edition Unix, also called Version 6 Unix or just V6 is a version of the Unix operating system first released in May 1975 and the first version of the Unix operating system to see wide release outside Bell Labs. Like its direct predecessor, t ...

ANSI C ANSI C, ISO C, and Standard C are successive standards for the C programming language published by the American National Standards Institute (ANSI) and ISO/IEC JTC 1/SC 22/WG 14 of the International Organization for Standardization (ISO) and the ...

for

multiprocessor Multiprocessing (MP) is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor or the ability to allocate tasks between them. The ...

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. Th ...

and

RISC-V RISC-V (pronounced "risk-five") is an open standard instruction set architecture (ISA) based on established reduced instruction set computer (RISC) principles. The project commenced in 2010 at the University of California, Berkeley. It transfer ...

systems. It was created for educational purposes in

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

's Operating System Engineering course in 2006.

Purpose

MIT's Operating System Engineering course formerly used the original V6 source code. xv6 was created as a modern replacement, because

PDP-11 The PDP–11 is a series of 16-bit minicomputers originally sold by Digital Equipment Corporation (DEC) from 1970 into the late 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of a ...

machines are not widely available and the original operating system was written in archaic pre-ANSI C. Unlike

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

BSD The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginni ...

, xv6 is simple enough to cover in a semester, yet still contains the important concepts and organization of

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

Self-documentation

One feature of the

Makefile In software development, Make is a command-line interface software tool that performs actions ordered by configured Dependence analysis, dependencies as defined in a configuration file called a ''makefile''. It is commonly used for build automati ...

for xv6 is the option to produce a

PDF Portable document format (PDF), standardized as ISO 32000, is a file format developed by Adobe Inc., Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, computer hardware, ...

of the entire source code listing in a readable format. The entire printout is only 99 pages, including cross references. 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.''

Educational use

xv6 has been used in operating systems courses at many universities, including: *

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University of the Andes (Colombia) The University of the Andes (), also commonly self-styled as Uniandes, is a private research university located in the city centre of Bogotá, Colombia. Founded in 1948 by a group of Colombian intellectuals led by Mario Laserna Pinzón, it was ...

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Binghamton University The State University of New York at Binghamton (Binghamton University or SUNY Binghamton) is a public university, public research university in Binghamton metropolitan area, Greater Binghamton, New York, United States. It is one of the four uni ...

Boston College Boston College (BC) is a private university, private Catholic Jesuits, Jesuit research university in Chestnut Hill, Massachusetts, United States. Founded in 1863 by the Society of Jesus, a Catholic Religious order (Catholic), religious order, t ...

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* Ghulam Ishaq Khan Institute *

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* IIIT Allahabad * IIT Bhubaneswar and PEC Chandigarh *

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IIT Delhi Indian Institute of Technology Delhi (IIT- Delhi) is a public institute of technology located in Delhi, India. It is one of the 23 Indian Institutes of Technology created to be a Centre of Excellence for India's training, research and developme ...

IIT Madras The Indian Institute of Technology Madras (IIT Madras or IIT-M) is a public technical university located in Chennai, Tamil Nadu, India. It is one of the eight public Institutes of Eminence of India. As an Indian Institute of Technology (IIT), ...

* IIIT Delhi * IIIT Bangalore *

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Iran University of Science and Technology Iran University of Science and Technology (IUST) (, ''Dâneshgâh-e 'elm va San'at-e Irân'') is a research institution and university of engineering and science in Iran. The university is home to 15 faculties offering undergraduate and postgr ...

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Karlsruhe Institute of Technology The Karlsruhe Institute of Technology (KIT; ) is both a German public research university in Karlsruhe, Baden-Württemberg, and a research center of the Helmholtz Association. KIT was created in 2009 when the University of Karlsruhe (), founde ...

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* National University of Río Cuarto *

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References

External links

6.1810: Operating Systems Engineering
RISC-V:
xv6 source code

xv6 book source code

xv6: a simple, Unix-like teaching operating system
xv6 book rev4. x86 (unmaintained):
xv6 source code

xv6 book source code

xv6: a simple, Unix-like teaching operating system
xv6 book rev11.
Printable version of the xv6 source code
rev11. {{unix-like Educational operating systems Free software operating systems Massachusetts Institute of Technology software Software using the MIT license Unix variants X86 operating systems

Purpose

Self-documentation

Educational use

See also

References

External links