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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node7.html b/sag-0.6.1-www/Invisible/sag-0.6/node7.html new file mode 100644 index 0000000..20297e9 --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node7.html @@ -0,0 +1,82 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>Important parts of the kernel</TITLE> +<META NAME="description" CONTENT="Important parts of the kernel"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html375" HREF="node8.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html373" HREF="node5.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html367" HREF="node6.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html377" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html378" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html376" HREF="node8.html">Major services in a </A> +<B>Up:</B> <A NAME="tex2html374" HREF="node5.html">Overview of a Linux </A> +<B> Previous:</B> <A NAME="tex2html368" HREF="node6.html">Various parts of an </A> +<BR> <P> +<H1><A NAME="SECTION00320000000000000000">Important parts of the kernel</A></H1> +<P> + The Linux kernel consists of several important parts: process + management, memory management, hardware device drivers, filesystem + drivers, network management, and various other bits and pieces. + Figure <A HREF="node7.html#figkerneloverview">2.1</A> shows some of them. +<A NAME="142"> </A> +<A NAME="143"> </A> +<A NAME="144"> </A> +<A NAME="145"> </A> +<A NAME="146"> </A> +<P> +<P><A NAME="151"> </A><A NAME="figkerneloverview"> </A><IMG WIDTH=626 HEIGHT=547 ALIGN=BOTTOM ALT="figure147" SRC="img2.gif"><BR> +<STRONG>Figure 2.1:</STRONG> Some of the more important parts of the Linux kernel.<BR> +<P> +<P> + Probably the most important parts of the kernel (nothing else + works without them) are memory management and + process management. Memory management takes care of assigning + memory areas and swap space areas to processes, parts of the + kernel, and for the buffer cache. Process management creates + processes, and implements multitasking by switching the + active process on the processor. +<A NAME="154"> </A> +<A NAME="155"> </A> +<A NAME="156"> </A> +<P> + At the lowest level, the kernel contains a hardware device + driver for each kind of + hardware it supports. Since the world is full of different + kinds of hardware, the number of hardware device drivers is + large. There are often many otherwise similar pieces of + hardware that differ in how they are controlled by software. + The similarities make it possible to have general classes + of drivers that support similar operations; each member of + the class has the same interface to the rest of the kernel + but differs in what it needs to do to implement them. For + example, all disk drivers look alike to the rest of the + kernel, i.e., they all have operations like `initialize the + drive', `read sector N', and `write sector N'. +<P> + Some software services provided by the kernel itself have similar + properties, and can therefore be abstracted into classes. + For example, the various network protocols have been + abstracted into one programming interface, the BSD socket library. + Another example is the <b>virtual filesystem</b> (VFS) layer + that abstracts the filesystem operations away from their + implementation. Each filesystem type provides an implementation + of each filesystem operation. When some entity tries to + use a filesystem, the request goes via the VFS, which routes + the request to the proper filesystem driver. +<A NAME="158"> </A> +<A NAME="159"> </A> +<A NAME="160"> </A> +<P> +<HR><A NAME="tex2html375" HREF="node8.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html373" HREF="node5.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html367" HREF="node6.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html377" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html378" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html376" HREF="node8.html">Major services in a </A> +<B>Up:</B> <A NAME="tex2html374" HREF="node5.html">Overview of a Linux </A> +<B> Previous:</B> <A NAME="tex2html368" HREF="node6.html">Various parts of an </A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |