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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node67.html b/sag-0.6.1-www/Invisible/sag-0.6/node67.html new file mode 100644 index 0000000..6a13703 --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node67.html @@ -0,0 +1,72 @@ +<!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>An overview of boots and shutdowns</TITLE> +<META NAME="description" CONTENT="An overview of boots and shutdowns"> +<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="tex2html1158" HREF="node68.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1156" HREF="node66.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1150" HREF="node66.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1160" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1161" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1159" HREF="node68.html">The boot process in </A> +<B>Up:</B> <A NAME="tex2html1157" HREF="node66.html">Boots And Shutdowns</A> +<B> Previous:</B> <A NAME="tex2html1151" HREF="node66.html">Boots And Shutdowns</A> +<BR> <P> +<H1><A NAME="SECTION00710000000000000000">An overview of boots and shutdowns</A></H1> +<P> + The act of turning on a computer system and causing its operating + system to be loaded<A NAME="tex2html29" HREF="footnode.html#1961"><IMG ALIGN=BOTTOM ALT="gif" SRC="./foot_motif.gif"></A> is called <b>booting</b>. The name + comes from an image of the computer pulling itself up from its + bootstraps, but the act itself slightly more realistic. +<A NAME="1963"> </A> +<A NAME="1964"> </A> +<P> + During bootstrapping, the computer first loads + a small piece of code called the <b>bootstrap loader</b>, + which in turn loads and starts + the operating system. The bootstrap loader is usually + stored in a fixed location on a hard disk or a floppy. The + reason for this two step process is that the operating system + is big and complicated, but the first piece of code that the + computer loads must be very small (a few hundred bytes), to avoid + making the firmware unnecessarily complicated. +<A NAME="1966"> </A> +<P> + Different computers do the bootstrapping differently. For PC's, + the computer (its BIOS) reads in the first sector (called + the <b>boot sector</b>) of a floppy or hard disk. + The bootstrap loader + is contained within this sector. It loads the operating + system from elsewhere on the disk (or from some other place). +<A NAME="1968"> </A> +<P> + After Linux has been loaded, it initializes the hardware and + device drivers, and then runs <tt>init</tt><A NAME="2115"> </A>. <tt>init</tt><A NAME="2117"> </A> + starts other processes to allow users to log in, and do things. + The details of this part will be discussed below. +<P> + In order to shut down a Linux system, first all processes + are told to terminate (this makes them close any files and + do other necessary things to keep things tidy), then filesystems + and swap areas are unmounted, and finally a message is printed + to the console that the power can be turned off. If the proper + procedure is not followed, terrible things can and will happen; + most importantly, the filesystem buffer cache might not be flushed, + which means that all data in it is lost and the filesystem on + disk is inconsistent, and therefore possibly unusable. +<A NAME="1971"> </A> +<A NAME="1972"> </A> +<P> +<HR><A NAME="tex2html1158" HREF="node68.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1156" HREF="node66.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1150" HREF="node66.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1160" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1161" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1159" HREF="node68.html">The boot process in </A> +<B>Up:</B> <A NAME="tex2html1157" HREF="node66.html">Boots And Shutdowns</A> +<B> Previous:</B> <A NAME="tex2html1151" HREF="node66.html">Boots And Shutdowns</A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |