LINUX System Components

LINUX System Components
Kernel
Shell
• Kernel
– Directly interacts with the hardware, provides common
services to program, and gives insulation from hardware
characteristics.
– Consists of file subsystem, process control subsystem, device
drivers and system calls interfaces.
– Even number kernels vs Odd number kernels
• Shell
– A program that takes commands typed in at the terminal and
translates them into instruction to internal system.
– Eg. Bourne shell (sh), C shell (csh), Korn shell (ksh), etc
The Linux Kernel
• Version 0.01 (May 1991) had no networking, ran only on
80386-compatible Intel processors and on PC hardware,
had extremely limited device-drive support, and supported
only the Minix file system.
• Linux 1.0 (March 1994) included these new features:
– Support for UNIX’s standard TCP/IP networking
protocols
– BSD-compatible socket interface for networking
programming
– Device-driver support for running IP over an Ethernet
– Enhanced file system
– Support for a range of SCSI controllers for
high-performance disk access
– Extra hardware support
• Version 1.2 (March 1995) was the final PC-only Linux
kernel.
Linux 2.0
• Released in June 1996, 2.0 added two major new
capabilities:
– Support for multiple architectures, including a fully 64-
bit native Alpha port.
– Support for multiprocessor architectures
• Other new features included:
– Improved memory-management code
– Improved TCP/IP performance
– Support for internal kernel threads, for handling
dependencies between loadable modules, and for
automatic loading of modules on demand.
– Standardized configuration interface
• Available for Motorola 68000-series processors, Sun
Sparc systems, and for PC and PowerMac systems.
Linux Distributions
• Vary according to included software packages,
package management systems, installation process,
and Window Managers.
• Distributions
– Red Hat Linux
– Caldera OpenLInux
– Linux Mandrake
– Corel Linux
– SuSE Linux
– TurboLinux
– Debian GNU/Linux
– Slackware