Download OVERVIEW: Linux and Unix

(Operating System Comparison)
RONG LIU
Introduction(1)
What is Linux?


The free UNIX written from scratch by Linus
Torvalds, assistance from a loosely-knit team of
hackers from across the internet.
A modern, fully fledged UNIX: true multitasking,
virtual memory, shared libraries, demand loading,
shared, copy-on-write executables, proper
memory management, and TCP/IP networking.
Introduction(2)
History of Unix
• In April, 1969, Ken Thompson, Brian Kernighan and
Dennis Ritchie sketched out an operating system that would
meet Bell Labs' needs, soon become Unix.
• In 1973, UNIX, was rewritten in C as Version 4 by Dennis
Ritchie and Brian Kernighan.
• Two major hot-beds of Unix development were at the
University of California, Berkeley, which later became BSD
(Berkeley Software Distribution), and M.I.T., which
eventually gave us the Free Software Foundation and the
GNU project, and the X Window System.
Introduction(2) (Cont...)
History of Unix
• Unix today has two major versions: System V (or
SVR4 from Unix System) and BSD (Berkeley Software
Distribution).
• UNIX (upper case) is a trademark of The Open
Group.
• Unix refers to Unix versions in general, regardless of
the source; usually it is simply referred to as SVR4 or
BSD 4.4.
Linux operating system overview
•
•
•
•
Memory Management:
– Page Allocation
– The Linux Page Cache
– The Swap Cache
Processes
The Linux Networking
Linux PCI Initialization
Processes
Processes have following
states:
•
•
•
•
Running
Waiting
Stopped
Zombie
The Linux Networking
Linux supports the following socket
address families or domains:
• UNIX -- Unix domain sockets.
• INET -- communications via
TCP/IP.
• AX25 -- Amateur radio X25.
• IPX -- Novell IPX
• AppleTalk -- AppleTalk DDP
• X25 -- X25
Linux PCI Initialization

PCI Device Driver


A. builds a linked list of data structures describing the
topology of the system.
B. numbers all of the bridges that it finds.

PCI BIOS

provides the services described in bib-pci-bios-specification.

PCI Fixup
 tidies up the system specific loose ends of PCI
initialization.
Unix operating system overview



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
OS Structure
File System
Directories Structure
Common Control Keys
Unix Shells
Unix OS Structure
Shell Editors,
Private User programs
Kernel
Hardware
Unix file system
Unix Directories Structure
1). Every directory and file is listed in its parent
directory.
2). Each file assigned inode number, an inode is a
special file designed to be read by the kernel to learn
the information about each file.
3). The system does not require any particular structure
for the data in the file itself. i.e. It can be ASCII,
binary or a combination.
4). There's no header, trailer, label information or EOF
character as part of the file.
Unix Common Control Keys
CONTROL
-C: Standard interrupt key;
CONTROL
-U: The key deletes the entire line;
CONTROL
-H: Use to erase the characters;
CONTROL
-W: Deletes the word you are entering;
CONTROL
-R: Moves cursor to next line;
CONTROL
-D: Logs out from shell prompt;
CONTROL
-S: Stops terminal accepting input;
CONTROL
-Q: Starts terminal accepting input.
Unix Shells

The shell sits between you and the operating
system, acting as a command interpreter. The
common shells as follow:
 1). Bourne shell, sh($) was the original shell.
 2). C shell prompt is %.
 3). Korn shell, ksh has nearly all the features
of Bourne Shell, maximixes execution speed
of scripts.
Linux compares with Unix
Similarity of Linux and Unix
The File systems
Shared Virtual Memory
Inter-Process
Communication
Identifiers
Executing Programs
EXT2 File System
Compare Linux2.2 with Solaris7.0(1)
OS convenience
Linux 2.2
Bugfixes and
other updates
Run a GUI app
on one machine
Diaplay it on
another .
Virus
Freely download able, and
available on CD. Both a
stable and a bleeding-edge
version is available.
yes
no
Solaris 7.0
Some (all???) minor
updates/bugfixes can be
downloaded freely.
Subscription customers get's
major upgrades on CD.
yes
no
Compare Linux2.2 with Solaris7.0(2)
OS
Linux 2.2
Single Unix
Specification v.1
(UNIX95)
Single Unix
Specification v.2
(UNIX98)
Address
space
Multiple CPU's
Max. file size
Max. file system size
OS Flavor
Solaris 7.0
no
yes
no
yes
no
no
SMP up to 16 CPU's, much improved
performance in comparison to 2.0.*, clustering
2 GB (ext2)
16 TB (ext2)
Designed from scratch to be Posix and now
Unix98 compliant.
Has some backwards
SMP on both Sparc and Intel 64 CPU's on
sparc
1 TB (on UltraSparc)
1 TB (on UltraSparc)
SysV R4
Compare Linux2.2 with Solaris7.0(3)
OS(Con.)
Memory protection
POSIX.1
certification
Threads
XPG4
base 95
Linux 2.2
Solaris 7.0
Yes
Yes
A posix.1 certified Linux 2.0.* kernel is available
from Unifix.
The main kernel is designed to be posix complient,
but haven't been certified.
posix 1003.1c
no
Yes
posix 1003.1c
Yes
Compare Linux2.2 with Solaris7.0(4)
Provider
Linux 2.2
Manufactor
Pricing
Developed, programmed and maintained
by a big group of people from all over the
world.
free
Solaris 7.0
Sun Microsystems Inc.
901 San Antonio Road
Palo Alto
CA 94303 USA
pay-ware or 2 year
subscriptions
Compare Linux2.2 with Solaris7.0(5)
Hardware
Linux 2.2
Peripherals
Most PC hardware.
Platforms
PC >= 386, Digital Alpha, Sparc,
UltraSparc, PPC, StrongARM
More are in development
Solaris 7.0
All current Sparc
peripherals, some PC
peripherals.
Sparc and PC >= 386
Reference:
1)."Linux at work ( building Strategic Applications
for Business)" by Marcus Concalves.
2). "Peter Norton's Complete Guide to Linux" by
Peter Norton and Arthur Grifficth.
3). “UNIX System V(Practical Guide) “by Mark G.
Sobell.
4). “Operating Systems” by William Stallings.
5). Web page at http://www.cs.utexas.edu.
6). Web page at http://www.idealcorp.com.
7). Web page at http://www.Linuxrx.org.