Seminar Origins of Operating Systems

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SeminarOrigins of Operating Systems

• The Microkernel Mach
• in NeXTSTEP
• Gregor Schmidt
• 2006-06-29

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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Overview

• Introduction
• The road to NeXTSTEP
• The NeXT computers
• The NeXTSTEP operating system
• The Mach Microkernel
• Interprocess Communication by example
• The next steps

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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Overview

• Introduction
• The NeXTSTEP operating system
• The Mach Microkernel
• The next steps

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Road to NeXTStep

• 1986 - NeXT computers, Inc. was founded by Steve
  Jobs and
• colleagues from Apple
• Rich Page
• George Crow
• Bud Tribble
• DanL Lewin
• Susan Barnes
• and
• Randy Heffner
• Gary H. Moore
• 1988 - The first computer was presented

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The NeXT computers

• based on Motorola 680x0
• 2 basic models
• NeXTcube (1989)
• NeXTstation (1990)
• 25 MHz resp. 33 MHz
• 8 MB RAM (up to 32 MB)
• 105 MB SCSI HDD
• Floppy Disc Drive
• 10Base-T and 10Base-2 Ethernet
• Monochrome Display
• All later versions of NeXTSTEP operating systems
  run on these machines

4.995,-
Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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Overview

• Introduction
• The NeXTSTEP operating system
• The Mach Microkernel
• The next steps

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The NeXTStep Operating SystemMain Features

• Mach Kernel
• BSD4.3 user space server
• NeXTSTEP user interface
• Display Postscript
• Object-oriented application framework
• Objective C as standard programming language
• Extraordinary OO-development tools
• High integration of all native applications

1988 - BSD re-factoring 1990 - BSD-Reno for Mach
Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The NeXTSTEP Operating SystemDemo - By Steve Jobs

• Product Demonstration of NeXTSTEP Release 3.0

100 Start 630 Word Perfect 2400 Interface
Builder
Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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Overview

• Introduction
• The NeXTSTEP operating system
• The Mach Microkernel
• The next steps

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelHistory

• 1985 - 1994 - developed at Carnegie-Mellon
  university
• Microkernel
• Deployed in several systems
• NeXTSTEP / OPENSTEP - Rhapsody - Mac OS X
• GNU/Hurd
• MkLinux
• Tru64 (OSF/1)
• NeXTSTEP uses Mach 2.5

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelMicrokernel

• Little features - great reliability
• Only the main features run in privileged mode
• Process management
• Scheduling
• Synchronization and communication
• Device drivers and all other services run as user
  services

• lots of communication overhead
• lots of synchronization

• small interface
• little trusted computing base

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelMain Features

• Preemptive Multitasking
• Multithreading, Multiprocessing
• Memory protection, virtual memory
• Interprocess communication via mach messages

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelInterprocess Communication

• Transparent network support
• Typed messages
• including type conversion between different
  languages
• Integrated with virtual memory
• local messages are not copied
• but mapped into receivers address space
• Remote messages are send lazily
• Port Rights Management
• Ownership
• Receive
• Send
• Port names - unique Integer

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelHow to find Ports in NeXTStep

• Environment Manager
• for local use only
• Network Message Server
• enables network-wide communication
• Service Server

• in Mac OS X Bootstrap Server

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelMessage Sending the Easy Way

• Mach Interface Generator
• Corba-like Stub-and-Skeleton-Generator

• Message encoding anddecoding for free
• Little RPC-specific code

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The Mach MicrokernelInterprocess Communication
by Example

• Calculator example
• Server providing calculation facilities
• Client using command line interface to receive
  tasks and queries server for the answer

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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Overview

• Introduction
• The NeXTSTEP operating system
• The Mach Microkernel
• The next steps

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The next steps

• 1995 - reorganization of NeXT towards software
• NeXT computers, Inc. - NeXT software, Inc.
• NeXTSTEP - OPENSTEP
• support for different platforms
• all NeXT computers
• Intel based computers
• PA-RISC Workstations
• Sun SPARC
• (IBM PPC) in labs
• WebObjects - first application server

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The next stepsOpenStep and OPENSTEP

• OpenStep is an object oriented API
• Designed by NeXT and Sun
• OPENSTEP is an implementation
• Other for
• Windows NT
• Solaris
• Linux - GNUStep
• Main components
• Display PostScript
• Objective-C Runtime and Compilers
• Majority of NeXTSTEP's Objective-C libraries

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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The next steps

• 1996 - take over by Apple, Inc. - 400 Millions
  US
• OPENSTEP becomes Mac OS X
• with a new User Interface - Aqua
• but the same underlying system components
• Mach enhanced to XNU (hybrid kernel) within Darwin

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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References

• BOYKIN, Joseph KIRSCHEN, David LANGERMAN, Alan
  LoVERSO Susan Programming under Mach.
  Addison-Wesley UNIX and Open System Series, ISBN
  0-201-52739-1, Addison-Wesley 1993
• GARFINKEL, Simon L. MAHONEY, Michael K.
  NeXTSTEP PROGRAMMING STEP ONE Object-Oriented
  Applications. TELOS. The Electronic Library of
  Science ISBN 0-387-97884-4, Springer-Verlag 1993
• POLZE, Andreas Vereiltes Rechnen unter Mach.
  unix/mail 2/1995, Carl Hanser Verlag München.
  Verfügbar im Internet lthttp//www.informatik.hu-b
  erlin.de/apolze/papers/um2-95.psgt. - online im
  Internet
• SLABIHOUD, Stephan NeXT Computer, Inc.,
  1998-2005, Verfügbar im Internet
  lthttp//www.8bit-museum.de/docs/next1.htmgt.
  Stand Juni 2006 - online im Internet
• Special References
• en.wikipedia.org - for lots of information around
  NeXTStep and Mach
• lists.apple.com - for good code example and
  special information

Gregor SchmidtOrigins of Operating Systems -
The Microkernel Mach
Betriebssysteme und Middleware / Prof. Andreas
Polze Hasso-Plattner-Institut

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