In
computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
, a single address space operating system (or SASOS) is an
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...
that provides only one globally shared
address space for all
processes. In a single address space operating system, numerically identical (
virtual memory
In computing, virtual memory, or virtual storage is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very l ...
)
logical address
In computing, a logical address is the address at which an item ( memory cell, storage element, network host) appears to reside from the perspective of an executing application program.
A logical address may be different from the physical addr ...
es in different processes all refer to exactly the same byte of data.
Single address-space operating systems offer certain advantages. In a traditional OS with private per-process address space, memory protection is based on address space boundaries ("address space isolation"). Single address-space operating systems use a different approach for memory protection that is just as strong. One advantage is that the same virtual-to-physical map
page table
A page table is the data structure used by a virtual memory system in a computer operating system to store the mapping between virtual addresses and physical addresses. Virtual addresses are used by the program executed by the accessing process, ...
can be used with every process (and in some SASOS, the kernel as well). This makes context switches on a SASOS faster than on operating systems that must change the page table and flush the
TLB caches on every context switch.
SASOS projects include the following:
* Amiga family –
AmigaOS
AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early version ...
,
AROS Aros may refer to:
*Aros (Middle-earth), a river in J. R. R. Tolkien's Middle-earth legendarium
* Aros, Mull, the location of Aros Castle, a ruined 13th-century castle on the Isle of Mull, Scotland
*AROS Research Operating System, a free software i ...
and
MorphOS
MorphOS is an AmigaOS-like computer operating system (OS). It is a mixed proprietary and open source OS produced for the Pegasos PowerPC (PPC) processor based computer, PowerUP accelerator equipped Amiga computers, and a series of Freescale dev ...
Angel*
BareMetal
BareMetal is an exokernel-based single address space operating system (OS) created by Return Infinity.
It is written in assembly to achieve high-performance computing with minimal footprint with a "just enough operating system" ( JeOS) approac ...
Br1X*
Genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
by Symbolics
*
IBM i (formerly called OS/400)
Iguanaat
NICTA
NICTA (formerly named National ICT Australia Ltd) was Australia's Information and Communications Technology (ICT) Research Centre of Excellence and is now known as CSIRO's Data61. The term "Centre of Excellence" is common marketing terminology u ...
, Australia
*
JX a research Java OS
*
IncludeOS
IncludeOS is a minimal, open source, unikernel operating system for cloud services and IoT. IncludeOS allows users to run C++ applications in the cloud without any operating system. IncludeOS adds operating system functionality to an application ...
Mungiat
NICTA
NICTA (formerly named National ICT Australia Ltd) was Australia's Information and Communications Technology (ICT) Research Centre of Excellence and is now known as CSIRO's Data61. The term "Centre of Excellence" is common marketing terminology u ...
, Australia
Nemesis*
OS-9
OS-9 is a family of real-time, process-based, multitasking, multi-user operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It was purchased by Radisys Corp in 2001, an ...
*
Phantom OS
Phantom OS is an operating system (OS) made by mostly Russian programmers (with help of some Uzbeks). It is based on a concept of persistent virtual memory, and uses a virtual machine, managed code, and bytecodes. It is one of a few OSes not bas ...
*
Scout
*
Singularity
Sombrero*
TempleOS
TempleOS (formerly J Operating System, LoseThos, and SparrowOS) is a biblical-themed lightweight operating system (OS) designed to be the Third Temple prophesied in the Bible. It was created by American programmer Terry A. Davis, who develope ...
Theseus OSTorsion*
VxWorks
VxWorks is a real-time operating system (or RTOS) developed as proprietary software by Wind River Systems, a wholly-owned subsidiary of Aptiv. First released in 1987, VxWorks is designed for use in embedded systems requiring real-time, determi ...
["Vxworks Tutorial"]
quote: "In vxworks ... all application tasks share the same address space nless theoptional tool named VxVMI as been
As, AS, A. S., A/S or similar may refer to:
Art, entertainment, and media
* A. S. Byatt (born 1936), English critic, novelist, poet and short story writer
* "As" (song), by Stevie Wonder
* , a Spanish sports newspaper
* , an academic male voic ...
used to allow each task to have its own address space."
*
Zephyr
In European tradition, a zephyr is a light wind or a west wind, named after Zephyrus, the Greek god or personification of the west wind.
Zephyr may also refer to:
Arts and media
Fiction Fiction media
* ''Zephyr'' (film), a 2010 Turkish ...
See also
*
Exokernel
Exokernel is an operating system kernel developed by the MIT Parallel and Distributed Operating Systems group, and also a class of similar operating systems.
Operating systems generally present hardware resources to applications through high-lev ...
*
Hybrid kernel
A hybrid kernel is an operating system Kernel (computer science), kernel architecture that attempts to combine aspects and benefits of microkernel and monolithic kernel architectures used in computer operating systems.
Overview
The traditional ker ...
*
Kernel
Kernel may refer to:
Computing
* Kernel (operating system), the central component of most operating systems
* Kernel (image processing), a matrix used for image convolution
* Compute kernel, in GPGPU programming
* Kernel method, in machine learn ...
*
Microkernel
In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...
*
Nanokernel
In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management ...
*
Unikernel
A unikernel is a specialised, single address space machine image constructed by using library operating systems. A developer selects, from a modular stack, the minimal set of libraries which correspond to the OS constructs required for the appl ...
*
Flat memory model
Flat memory model or linear memory model refers to a memory addressing paradigm in which "memory appears to the program as a single contiguous address space." The CPU can directly (and linearly) address all of the available memory locations witho ...
*
Virtual memory
In computing, virtual memory, or virtual storage is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" which "creates the illusion to users of a very l ...
References
Bibliography
* .
*
*
*
Operating systems
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