Date: Mon, 21 Apr 2014 21:29:57 +0000 (UTC) From: Dru Lavigne <dru@FreeBSD.org> To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r44622 - head/en_US.ISO8859-1/books/handbook/boot Message-ID: <201404212129.s3LLTvZ5040808@svn.freebsd.org>
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Author: dru Date: Mon Apr 21 21:29:57 2014 New Revision: 44622 URL: http://svnweb.freebsd.org/changeset/doc/44622 Log: Prep work for boot chapter. Add missing items from what is covered in this chapter list. Add note about GPT and EFI/UEFI. Some shuffling of headings to improve flow. More commits to come. Sponsored by: iXsystems Modified: head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Modified: head/en_US.ISO8859-1/books/handbook/boot/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Mon Apr 21 21:16:02 2014 (r44621) +++ head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Mon Apr 21 21:29:57 2014 (r44622) @@ -19,7 +19,7 @@ <para>The process of starting a computer and loading the operating system is referred to as <quote>the bootstrap process</quote>, - or simply <quote>booting</quote>. &os;'s boot process provides + or <quote>booting</quote>. &os;'s boot process provides a great deal of flexibility in customizing what happens when the system starts, including the ability to select from different operating systems installed on the same computer, @@ -47,18 +47,27 @@ </listitem> <listitem> - <para>The basics of &man.device.hints.5;.</para> + <para>How to configure a customized boot splash screen.</para> + </listitem> + + <listitem> + <para>The basics of setting device hints.</para> + </listitem> + + <listitem> + <para>How to boot into single- and multi-user mode and how to + properly shutdown a &os; system.</para> </listitem> </itemizedlist> <note> <para>This chapter only describes the boot process for &os; - running on Intel x86 systems.</para> + running on x86 and amd64 systems.</para> </note> </sect1> <sect1 xml:id="boot-introduction"> - <title>The Booting Problem</title> + <title>&os; Boot Process</title> <para>Turning on a computer and starting the operating system poses an interesting dilemma. By definition, the computer does @@ -71,7 +80,7 @@ <para>This problem parallels one in the book <citetitle>The Adventures of Baron Munchausen</citetitle>. A character had fallen part way down a manhole, and pulled himself - out by grabbing his bootstraps, and lifting. In the early days + out by grabbing his bootstraps and lifting. In the early days of computing the term <firstterm>bootstrap</firstterm> was applied to the mechanism used to load the operating system, which has become shortened to <quote>booting</quote>.</para> @@ -81,9 +90,9 @@ <indexterm><primary>Basic Input/Output System</primary><see><acronym>BIOS</acronym></see></indexterm> - <para>On x86 hardware the Basic Input/Output System + <para>On x86 hardware, the Basic Input/Output System (<acronym>BIOS</acronym>) is responsible for loading the - operating system. To do this, the <acronym>BIOS</acronym> + operating system. The <acronym>BIOS</acronym> looks on the hard disk for the Master Boot Record (<acronym>MBR</acronym>), which must be located in a specific place on the disk. The <acronym>BIOS</acronym> has enough @@ -91,6 +100,19 @@ assumes that the <acronym>MBR</acronym> can then carry out the rest of the tasks involved in loading the operating system, possibly with the help of the <acronym>BIOS</acronym>.</para> + + <note> + <para>amd64 hardware is backward compatible as it understands + <acronym>BIOS</acronym> instructions. Newer hardware uses + a GUID Partition Table (<acronym>GPT</acronym>) instead of a + <acronym>MBR</acronym>. &os; can boot from a + <acronym>MBR</acronym> or <acronym>GPT</acronym> partition. + When booting from <acronym>GPT</acronym>, &os; can boot from + either a legacy <acronym>BIOS</acronym> or an Extensible + Firmware Interface (<acronym>EFI</acronym>). Work is in + progress to provide Unified Extensible Firmware Interface + (<acronym>UEFI</acronym>) support.</para> + </note> <indexterm><primary>Master Boot Record <acronym>MBR</acronym>)</primary></indexterm> @@ -101,60 +123,50 @@ <para>The code within the <acronym>MBR</acronym> is usually referred to as a <emphasis>boot manager</emphasis>, especially - when it interacts with the user. In this case, the boot + when it interacts with the user. The boot manager usually has more code in the first - <emphasis>track</emphasis> of the disk or within the file - system of some operating systems. A boot manager is sometimes - also called a <emphasis>boot loader</emphasis>, but &os; uses - that term for a later stage of booting. Popular boot managers - include <application>boot0</application>, also called - <application>Boot Easy</application>, the standard &os; boot - manager, <application>Grub</application>, - <application>GAG</application>, and - <application>LILO</application>. Only - <application>boot0</application> fits within the - <acronym>MBR</acronym>.</para> + track of the disk or within the file + system. Examples of boot managers + include the standard &os; boot + manager <application>boot0</application>, also called + <application>Boot Easy</application>, and <application>Grub</application>, + which is used by many &linux; distributions.</para> - <para>If only one operating system is installed, a standard PC - <acronym>MBR</acronym> will suffice. This + <para>If only one operating system is installed, the <acronym>MBR</acronym> searches for the first bootable (active) slice on the disk, and then runs the code on that slice to load - the remainder of the operating system. By default, the - <acronym>MBR</acronym> installed by &man.fdisk.8; is such an - <acronym>MBR</acronym> and is based on - <filename>/boot/mbr</filename>.</para> - - <para>If multiple operating systems are present, a different boot + the remainder of the operating system. If multiple operating + systems are present, a different boot manager can be installed which displays the list of operating - systems so that the user can choose which one to boot from. Two - boot managers are discussed in the next subsection.</para> + systems so that the user can choose which one to boot from.</para> <para>The remainder of the &os; bootstrap system is divided into - three stages. The first stage is run by the - <acronym>MBR</acronym>, which knows just enough to get the + three stages. The first stage knows just enough to get the computer into a specific state and run the second stage. The second stage can do a little bit more, before running the third stage. The third stage finishes the task of loading the operating system. The work is split into three stages because - PC standards put limits on the size of the programs that can be + the <acronym>MBR</acronym> puts limits on the size of the programs that can be run at stages one and two. Chaining the tasks together allows &os; to provide a more flexible loader.</para> <indexterm><primary>kernel</primary></indexterm> <indexterm><primary>&man.init.8;</primary></indexterm> - <para>The kernel is then started and it begins to probe for + <para>The kernel is then started and begins to probe for devices and initialize them for use. Once the kernel boot process is finished, the kernel passes control to the user - process &man.init.8;, which then makes sure the disks are in a - usable state. &man.init.8; then starts the user-level resource + process &man.init.8;, which makes sure the disks are in a + usable state, starts the user-level resource configuration which mounts file systems, sets up network cards to communicate on the network, and starts the processes which - have been configured to run on a &os; system at startup.</para> - </sect1> + have been configured to run at startup.</para> + + <para>This section describes these stages in more detail and + demonstrates how to interact with the &os; boot process.</para> - <sect1 xml:id="boot-boot0"> - <title>The Boot Manager and Boot Stages</title> + <sect2 xml:id="boot-boot0"> + <title>The Boot Manager</title> <indexterm><primary>Boot Manager</primary></indexterm> @@ -232,6 +244,7 @@ label=FreeBSD</programlisting> run <command>/sbin/lilo -v</command> to commit the new changes. Verify these are correct by checking the screen messages.</para> + </sect2> <sect2 xml:id="boot-boot1"> <title>Stage One and Stage Two</title> @@ -605,6 +618,7 @@ boot:</screen> boot flags.</para> </note> </sect2> + </sect1> <!-- <sect2 id="boot-kernel-userconfig"> @@ -613,7 +627,7 @@ boot:</screen> <para> </para> </sect2> --> - <sect2 xml:id="boot-splash"> + <sect1 xml:id="boot-splash"> <info> <title>Configuring Boot Time Splash Screens</title> @@ -766,7 +780,6 @@ bitmap_name="<replaceable>/boot/splash.b <para>For more information, refer to &man.splash.4;, &man.loader.conf.5;, and &man.vga.4;.</para> - </sect2> </sect1> <sect1 xml:id="device-hints">
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