Coyotos
Encyclopedia
Coyotos is a capability-based
Capability-based security
Capability-based security is a concept in the design of secure computing systems, one of the existing security models. A capability is a communicable, unforgeable token of authority. It refers to a value that references an object along with an associated set of access rights...

 security-focused microkernel
Microkernel
In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system . These mechanisms include low-level address space management, thread management, and inter-process communication...

 operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 developed
Software engineering
Software Engineering is the application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software, and the study of these approaches; that is, the application of engineering to software...

 by The EROS Group, LLC. It is a successor to the EROS
Extremely Reliable Operating System
EROS is an operating system developed by The EROS Group, LLC., the Johns Hopkins University, and the University of Pennsylvania. Features include automatic data and process persistence, some preliminary real-time support, and capability-based security. EROS is purely a research operating system,...

 system that was created at the University of Pennsylvania
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...

 and Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...

.

History

Coyotos is considered by its creators to be an “evolutionary step” beyond the EROS
Extremely Reliable Operating System
EROS is an operating system developed by The EROS Group, LLC., the Johns Hopkins University, and the University of Pennsylvania. Features include automatic data and process persistence, some preliminary real-time support, and capability-based security. EROS is purely a research operating system,...

 operating system, which in turn was derived from KeyKOS
KeyKOS
KeyKOS is a persistent, pure capability-based operating system for the IBM S/370 mainframe computers. It allows emulating the VM, MVS, and POSIX environments. It is a predecessor of the Extremely Reliable Operating System , and its successors, the CapROS and Coyotos operating systems...

, itself coming from GNOSIS
GNOSIS
GNOSIS is a capability-based operating system that was researched during the 1970s in Tymshare, Inc. It was based on the research of Norman Hardy, Dale E. Jordan, Bill Frantz, Charlie Landau, Jay Jonekait, et al. It provided a foundation for the development of future operating systems such as...

 (Great New Operating System In the Sky). The primary developer of EROS was Jonathan S. Shapiro, who is also a driving force behind Coyotos and the BitC
BitC
BitC is a systems programming language developed by researchers at the Johns Hopkins University and as part of the Coyotos project. It aims to support formal program verification.-Objectives:The language has two primary objectives:...

 programming language. A more in-depth history is located at History:"The Path to Coyotos". In 2006 the Coyotos developers worked with the developers of GNU Hurd
GNU Hurd
GNU Hurd is a free software Unix-like replacement for the Unix kernel, released under the GNU General Public License. It has been under development since 1990 by the GNU Project of the Free Software Foundation...

 to make Coyotos a suitable microkernel for GNU Hurd. However, the Hurd project returned to the Mach
Mach (kernel)
Mach is an operating system kernel developed at Carnegie Mellon University to support operating system research, primarily distributed and parallel computation. Although Mach is often mentioned as one of the earliest examples of a microkernel, not all versions of Mach are microkernels...

 microkernel instead.

From April 2009 to March 2010, Jonathan Shapiro was employed by Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

 and was not working on Coyotos or BitC.

Status

Since March 2010, the main development effort has been on the BitC language being designed for use in Coyotos: as of March 2011, the last change to Coyotos was in June 2010.

Objectives

One of the Coyotos project's many objectives was to become the first formally verified
Formal verification
In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of intended algorithms underlying a system with respect to a certain formal specification or property, using formal methods of mathematics .- Usage :Formal verification can be...

 operating system. To support this, the project contributed to developing a new programming language
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....

 called BitC
BitC
BitC is a systems programming language developed by researchers at the Johns Hopkins University and as part of the Coyotos project. It aims to support formal program verification.-Objectives:The language has two primary objectives:...

 and a new compiler called BitCC.

This title now belongs to seL4, an L4-family microkernel developed by researchers from NICTA and the University of New South Wales
University of New South Wales
The University of New South Wales , is a research-focused university based in Kensington, a suburb in Sydney, New South Wales, Australia...

.

Microkernel

Coyotos has a microkernel design which “retains the atomicity and pure capability-based design of the EROS system”, but which “introduces a more efficient memory mapping mechanism”.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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