Introduction 1

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Chapter 1. Introduction

• History and Proliferation
• Mandate for Change
• Whats Good and Wrong
• Scope of this course

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History of UNIX

• Late 1960s, Bell Telephone Lab.
• Project with GE and MIT Multics
• Multics was canceled in March 1969
• Ken Thompson Space Travel game program
• UNIX on PDP-7 (DEC)
• PDP-11, B language
• 1973, released C compiler cc
• 1973, rewritten in C (version 4 UNIX)

3
Proliferation of UNIX

• 1973, UC Berkeley obtained UNIX
• 1979, Version 7 UNIX (portable UNIX)
• Microsoft and SCO XENIX on Intel 8086
• 1978, DEC 32-bit VAX-11 computer
• UNIX on VAX UNIX/32V
• UC Berkeley 3BSD, 1979

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Berkeley Software Distribution

• 3BSD, 1979
• paging-based virtual memory (on VAX-11)
• 4BSD by DARPA project
• Integrate TCP/IP, 4.0 BSD in 1980
• 4.1 BSD in 1981, 4.2 BSD in 1983
• 4.3 BSD in 1986
• 4.4 BSD in 1993
• UC Berkeley discontinue UNIX development

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System V

• Bell Telephone Lab.
• System III in 1982
• System V in 1983
• virtual memory different from BSD
• System V Release 2 (SVR2) in 1984
• SVR3 in 1987
• interprocess communication
• SVR4 in 1989
• security and multiprocessor

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Commercialization

• Sun Microsystems
• SunOS in 1982 (4.2 BSD-based)
• Network File System (NFS)
• Solaris (SVR4-based)
• MS, SCO
• XENIX, SCO UNIX
• IBM AIX, HP HP-UX
• DEC ULTRIX
• first multiprocessor UNIX

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Mach

• In mid-1980s, Carnegie-Mellon University
• Microkernel
• small set of essential services
• other functions at the user level
• Uni- and Multi-processor
• Distributed environment
• Mach 3.0 OSF/1 and NextStep

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Standards of UNIX

• Initially ATT System V and BSD.
• System V Interface Definition (SVID)
• System V-based
• IEEE POSIX Spec.
• Portable Operating Systems based on UNIX
• amalgam of core parts of SVR3 and 4.3BSD
• POSIX.1 in 1990
• X/Open Portability Guide
• based on POSIX.1

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OSF and UI

• Open Software Foundation
• 1988 DEC IBM HP
• free of ATT license encumbrances
• 1989, Motif GUI
• OSF/1 based on Mach 2.5
• Unix International
• ATT Sun
• marketing SVR4
• 1990s, economic downturn MS Windows

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Mandate for Change

• Functionality e.g. IPC
• Networking e.g. NFS, NIS, DCE
• Performance e.g. Fast file system
• Hardware Changes e.g. Multiprocessor, RAID
• Quality improvement
• Paradigm shifts
• from centralized to distributed (client-server)

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Traditional UNIX kernel
file system (s5fs)
virtual memory
loader (a.out)
kernel
block driver switch
character driver switch
disk driver
tape driver
printer driver
network driver
tty driver
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Modern UNIX kernel
filemappings
coff
elf
a.out
NFS
FFS
execswitch
devicemappings
s5fs
vnode/vfsinterface
virtualmemoryframework
RFS
commonfacilities
anonymousmappings
time-sharingprocesses
schedulerframework
block deviceswitch
real-timeprocesses
diskdriver
STREAMS
systemprocesses
tapedriver
networkdriver
tty driver
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Good about UNIX

• License and source code
• UC Berkeley
• small and well-designed
• simple file system
• uniform I/O interface
• portability

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Wrong with UNIX

• lack of a simple, uniform GUI
• variants of UNIX
• standardization vs. product differentiation
• bad for code reuse
• kernel became bloated, unmodular, and complex

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Scope of the Course

• Modern UNIX systems
• Baseline systems
• System V, 4BSD, and Mach
• Variant systems
• SunOS, Solaris 2.x, AIX, HP-UX, ULTRIX,
• Term project MS Windows NT