rong liu (operating system comparison). introduction(1) what is linux? the free unix written from...
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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
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
OS Structure File System Directories Structure Common Control Keys Unix Shells
Unix OS Structure
Hardware
Kernel
Shell Editors,
Private User programsC
ompi
ler
Com
pone
nts
Com
pile
r
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.
-C: Standard interrupt key;
-U: The key deletes the entire line;
-H: Use to erase the characters;
-W: Deletes the word you are entering;
-R: Moves cursor to next line;
-D: Logs out from shell prompt;
-S: Stops terminal accepting input;
-Q: Starts terminal accepting input.
Unix Common Control Keys
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
CONTROL
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
The File systemsShared Virtual Memory
Inter-Process Communication
Identifiers
Executing Programs
EXT2 File System
Similarity of Linux and Unix
Compare Linux2.2 with Solaris7.0(1)
OS convenience
Bugfixes and other updates
Linux 2.2 Solaris 7.0
Freely download able, and available on CD. Both a stable and a bleeding-edge version is available.
Some (all???) minor updates/bugfixes can be downloaded freely.Subscription customers get's major upgrades on CD.
Run a GUI app on one machineDiaplay it on another .
yes yes
Virus no no
Compare Linux2.2 with Solaris7.0(2)
OS
Single Unix Specification v.1
(UNIX95)
Linux 2.2 Solaris 7.0
Single Unix Specification v.2
(UNIX98)
yes
Address space
no no
no
no
yes
Multiple CPU's SMP up to 16 CPU's, much improved performance in comparison to 2.0.*, clustering SMP on both Sparc and Intel 64 CPU's on
sparcMax. file size
2 GB (ext2) 1 TB (on UltraSparc)
Max. file system size 16 TB (ext2) 1 TB (on UltraSparc)
OS FlavorDesigned from scratch to be Posix and now Unix98 compliant.
Has some backwards SysV R4
Compare Linux2.2 with Solaris7.0(3)
OS(Con.)
Linux 2.2 Solaris 7.0
Memory protection Yes Yes
POSIX.1 certification
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.
Yes
Threads posix 1003.1c posix 1003.1c
XPG4 base 95
no Yes
Compare Linux2.2 with Solaris7.0(4)
Provider
Linux 2.2 Solaris 7.0
ManufactorDeveloped, programmed and maintained by a big group of people from all over the world.
Sun Microsystems Inc.901 San Antonio RoadPalo AltoCA 94303 USA
Pricing free
pay-ware or 2 year subscriptions
Compare Linux2.2 with Solaris7.0(5)
Hardware
Linux 2.2 Solaris 7.0
Peripherals Most PC hardware.
All current Sparc peripherals, some PC peripherals.
PlatformsPC >= 386, Digital Alpha, Sparc, UltraSparc, PPC, StrongARMMore are in development
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.