Date: Tue, 22 Apr 2014 17:49:42 +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: r44628 - head/en_US.ISO8859-1/books/handbook/boot Message-ID: <201404221749.s3MHngEA049373@svn.freebsd.org>
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Author: dru Date: Tue Apr 22 17:49:42 2014 New Revision: 44628 URL: http://svnweb.freebsd.org/changeset/doc/44628 Log: White space fix only. Translators can ignore. 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 Tue Apr 22 16:40:50 2014 (r44627) +++ head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Tue Apr 22 17:49:42 2014 (r44628) @@ -19,12 +19,12 @@ <para>The process of starting a computer and loading the operating system is referred to as <quote>the bootstrap process</quote>, - 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, - different versions of the same operating system, or a different - installed kernel.</para> + 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, different versions of + the same operating system, or a different installed + kernel.</para> <para>This chapter details the configuration options that can be set. It demonstrates how to customize the &os; boot process, @@ -53,7 +53,7 @@ <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 shut down a &os; system.</para> @@ -77,13 +77,13 @@ operating system, and the operating system programs are on the disk, how is the operating system started?</para> - <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 - 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> + <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 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> <indexterm><primary><acronym>BIOS</acronym></primary></indexterm> @@ -92,15 +92,15 @@ <para>On x86 hardware, the Basic Input/Output System (<acronym>BIOS</acronym>) is responsible for loading the - 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 - knowledge to load and run the <acronym>MBR</acronym>, and - 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> - + 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 knowledge to load and run the + <acronym>MBR</acronym>, and 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 @@ -123,22 +123,21 @@ <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. The boot - manager usually has more code in the first - 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> + when it interacts with the user. The boot manager usually has + more code in the first 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, 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. 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.</para> + 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.</para> <para>The remainder of the &os; bootstrap system is divided into three stages. The first stage knows just enough to get the @@ -146,73 +145,73 @@ 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 - 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> + 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 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 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 at startup.</para> - - <para>This section describes these stages in more detail and - demonstrates how to interact with the &os; boot process.</para> - - <sect2 xml:id="boot-boot0"> - <title>The Boot Manager</title> - - <indexterm><primary>Boot Manager</primary></indexterm> - - <indexterm><primary>Master Boot Record - (<acronym>MBR</acronym>)</primary></indexterm> - - <para>The boot manager code in the <acronym>MBR</acronym> is - sometimes referred to as <emphasis>stage zero</emphasis> of the - boot process. By default, &os; uses the - <application>boot0</application> boot manager.</para> + <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 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 at + startup.</para> + + <para>This section describes these stages in more detail and + demonstrates how to interact with the &os; boot process.</para> + + <sect2 xml:id="boot-boot0"> + <title>The Boot Manager</title> + + <indexterm><primary>Boot Manager</primary></indexterm> + + <indexterm><primary>Master Boot Record + (<acronym>MBR</acronym>)</primary></indexterm> + + <para>The boot manager code in the <acronym>MBR</acronym> is + sometimes referred to as <emphasis>stage zero</emphasis> of + the boot process. By default, &os; uses the + <application>boot0</application> boot manager.</para> <para>The <acronym>MBR</acronym> installed by the &os; installer - is based on - <filename>/boot/boot0</filename>. The size and capability of - <application>boot0</application> is restricted to 446 bytes - due to the slice table and <literal>0x55AA</literal> - identifier at the end of the <acronym>MBR</acronym>. If - <application>boot0</application> and multiple operating - systems are installed, a message similar to this example will - be displayed at boot time:</para> + is based on <filename>/boot/boot0</filename>. The size and + capability of <application>boot0</application> is restricted + to 446 bytes due to the slice table and + <literal>0x55AA</literal> identifier at the end of the + <acronym>MBR</acronym>. If <application>boot0</application> + and multiple operating systems are installed, a message + similar to this example will be displayed at boot time:</para> - <example xml:id="boot-boot0-example"> - <title><filename>boot0</filename> Screenshot</title> + <example xml:id="boot-boot0-example"> + <title><filename>boot0</filename> Screenshot</title> - <screen>F1 Win + <screen>F1 Win F2 FreeBSD Default: F2</screen> - </example> + </example> - <para>Other operating systems will - overwrite an existing <acronym>MBR</acronym> if they are - installed after &os;. If this happens, or to replace the - existing <acronym>MBR</acronym> with the &os; - <acronym>MBR</acronym>, use the following command:</para> - - <screen>&prompt.root; <userinput>fdisk -B -b /boot/boot0 <replaceable>device</replaceable></userinput></screen> - - <para>where <replaceable>device</replaceable> is the boot disk, - such as <filename>ad0</filename> for the first - <acronym>IDE</acronym> disk, <filename>ad2</filename> for the - first <acronym>IDE</acronym> disk on a second - <acronym>IDE</acronym> controller, or <filename>da0</filename> - for the first <acronym>SCSI</acronym> disk. To create a - custom configuration of the <acronym>MBR</acronym>, refer to - &man.boot0cfg.8;.</para> + <para>Other operating systems will overwrite an existing + <acronym>MBR</acronym> if they are installed after &os;. If + this happens, or to replace the existing + <acronym>MBR</acronym> with the &os; <acronym>MBR</acronym>, + use the following command:</para> + + <screen>&prompt.root; <userinput>fdisk -B -b /boot/boot0 <replaceable>device</replaceable></userinput></screen> + + <para>where <replaceable>device</replaceable> is the boot disk, + such as <filename>ad0</filename> for the first + <acronym>IDE</acronym> disk, <filename>ad2</filename> for the + first <acronym>IDE</acronym> disk on a second + <acronym>IDE</acronym> controller, or <filename>da0</filename> + for the first <acronym>SCSI</acronym> disk. To create a + custom configuration of the <acronym>MBR</acronym>, refer to + &man.boot0cfg.8;.</para> </sect2> <sect2 xml:id="boot-boot1"> @@ -225,25 +224,26 @@ Default: F2</screen> <filename>/boot/boot</filename> by the &os; installer or <command>bsdlabel</command>.</para> - <para>These two stages are located outside file systems, in the first track - of the boot slice, starting with the first sector. This is - where <application>boot0</application>, or any other + <para>These two stages are located outside file systems, in the + first track of the boot slice, starting with the first sector. + This is where <application>boot0</application>, or any other boot manager, expects to find a program to run which will continue the boot process.</para> - <para>The first stage, <filename>boot1</filename>, is very simple, since it can - only be 512 bytes in size. It knows just enough about the - &os; <firstterm>bsdlabel</firstterm>, which stores - information about the slice, to find and execute + <para>The first stage, <filename>boot1</filename>, is very + simple, since it can only be 512 bytes in size. It knows just + enough about the &os; <firstterm>bsdlabel</firstterm>, which + stores information about the slice, to find and execute <filename>boot2</filename>.</para> - <para>Stage two, <filename>boot2</filename>, is slightly more sophisticated, - and understands the &os; file system enough to find files. It - can provide a simple interface to choose the kernel or loader - to run. It runs <application>loader</application>, which is much more sophisticated and - provides a boot configuration file. If the boot process is - interrupted at stage two, the following interactive screen is - displayed:</para> + <para>Stage two, <filename>boot2</filename>, is slightly more + sophisticated, and understands the &os; file system enough to + find files. It can provide a simple interface to choose the + kernel or loader to run. It runs + <application>loader</application>, which is much more + sophisticated and provides a boot configuration file. If the + boot process is interrupted at stage two, the following + interactive screen is displayed:</para> <example xml:id="boot-boot2-example"> <title><filename>boot2</filename> Screenshot</title> @@ -253,23 +253,21 @@ Default: 0:ad(0,a)/boot/loader boot:</screen> </example> - <para>To replace the installed - <filename>boot1</filename> and + <para>To replace the installed <filename>boot1</filename> and <filename>boot2</filename>, use <command>bsdlabel</command>, where <replaceable>diskslice</replaceable> is the disk and - slice to boot from, such as <filename>ad0s1</filename> - for the first slice on the first <acronym>IDE</acronym> - disk:</para> + slice to boot from, such as <filename>ad0s1</filename> for the + first slice on the first <acronym>IDE</acronym> disk:</para> <screen>&prompt.root; <userinput>bsdlabel -B <replaceable>diskslice</replaceable></userinput></screen> <warning> <para>If just the disk name is used, such as - <filename>ad0</filename>, <command>bsdlabel</command> will create the disk in - <quote>dangerously dedicated mode</quote>, without slices. - This is probably not the desired action, so double check the - <replaceable>diskslice</replaceable> - before pressing + <filename>ad0</filename>, <command>bsdlabel</command> will + create the disk in <quote>dangerously dedicated + mode</quote>, without slices. This is probably not the + desired action, so double check the + <replaceable>diskslice</replaceable> before pressing <keycap>Return</keycap>.</para> </warning> </sect2> @@ -279,20 +277,21 @@ boot:</screen> <indexterm><primary>boot-loader</primary></indexterm> - <para>The <application>loader</application> is the final stage of the three-stage - bootstrap process. It is located on the file system, usually as + <para>The <application>loader</application> is the final stage + of the three-stage bootstrap process. It is located on the + file system, usually as <filename>/boot/loader</filename>.</para> - <para>The <application>loader</application> is intended as an interactive method for - configuration, using a built-in command set, backed up by a - more powerful interpreter which has a more complex command - set.</para> - - <para>During initialization, <application>loader</application> will probe for a - console and for disks, and figure out which disk it is - booting from. It will set variables accordingly, and an - interpreter is started where user commands can be passed from - a script or interactively.</para> + <para>The <application>loader</application> is intended as an + interactive method for configuration, using a built-in command + set, backed up by a more powerful interpreter which has a more + complex command set.</para> + + <para>During initialization, <application>loader</application> + will probe for a console and for disks, and figure out which + disk it is booting from. It will set variables accordingly, + and an interpreter is started where user commands can be + passed from a script or interactively.</para> <indexterm><primary>loader</primary></indexterm> <indexterm><primary>loader configuration</primary></indexterm> @@ -306,15 +305,15 @@ boot:</screen> these variables, loading whichever modules and kernel are selected.</para> - <para>Finally, by default, <application>loader</application> issues a 10 second wait - for key presses, and boots the kernel if it is not - interrupted. If interrupted, the user is presented with a - prompt which understands the command set, where the user may - adjust variables, unload all modules, load modules, and then - finally boot or reboot. <xref - linkend="boot-loader-commands"/> lists the most - commonly used <application>loader</application> commands. For - a complete discussion of all available commands, refer to + <para>Finally, by default, <application>loader</application> + issues a 10 second wait for key presses, and boots the kernel + if it is not interrupted. If interrupted, the user is + presented with a prompt which understands the command set, + where the user may adjust variables, unload all modules, load + modules, and then finally boot or reboot. <xref + linkend="boot-loader-commands"/> lists the most commonly + used <application>loader</application> commands. For a + complete discussion of all available commands, refer to &man.loader.8;.</para> <table xml:id="boot-loader-commands" frame="none" pgwide="1"> @@ -326,145 +325,142 @@ boot:</screen> <entry>Variable</entry> <entry>Description</entry> </row> - </thead> - + </thead> + <tbody> <row> - <entry>autoboot <replaceable>seconds</replaceable></entry> + <entry>autoboot + <replaceable>seconds</replaceable></entry> <entry>Proceeds to boot the kernel if not interrupted within the time span given, in seconds. It displays a countdown, and the default time span is 10 seconds.</entry> </row> - <row> - <entry>boot - <optional><replaceable>-options</replaceable></optional> - <optional><replaceable>kernelname</replaceable></optional></entry> - <entry>Immediately proceeds to boot the kernel, with any - specified options or kernel name. Providing a kernel - name on the command-line is only applicable after an - <command>unload</command> has been issued. + <row> + <entry>boot + <optional><replaceable>-options</replaceable></optional> + <optional><replaceable>kernelname</replaceable></optional></entry> + <entry>Immediately proceeds to boot the kernel, with + any specified options or kernel name. Providing a + kernel name on the command-line is only applicable + after an <command>unload</command> has been issued. Otherwise, the previously-loaded kernel will be used.</entry> </row> - <row> - <entry>boot-conf</entry> - <entry>Goes through the same automatic configuration of + <row> + <entry>boot-conf</entry> + <entry>Goes through the same automatic configuration of modules based on specified variables, most commonly <envar>kernel</envar>. This only makes sense if <command>unload</command> is used first, before changing some variables.</entry> </row> - <row> - <entry>help - <optional><replaceable>topic</replaceable></optional></entry> - <entry>Shows help messages read from + <row> + <entry>help + <optional><replaceable>topic</replaceable></optional></entry> + <entry>Shows help messages read from <filename>/boot/loader.help</filename>. If the topic given is <literal>index</literal>, the list of available topics is displayed.</entry> </row> - <row> - <entry>include <replaceable>filename</replaceable> - …</entry> - <entry>Reads the specified file and interprets it line by line. An - error immediately stops the <command>include</command>.</entry> + <row> + <entry>include <replaceable>filename</replaceable> + …</entry> + <entry>Reads the specified file and interprets it line + by line. An error immediately stops the + <command>include</command>.</entry> </row> - <row> - <entry>load <optional>-t - <replaceable>type</replaceable></optional> - <replaceable>filename</replaceable></entry> - <entry>Loads the kernel, kernel module, or file of the + <row> + <entry>load <optional>-t + <replaceable>type</replaceable></optional> + <replaceable>filename</replaceable></entry> + <entry>Loads the kernel, kernel module, or file of the type given, with the specified filename. Any arguments after <replaceable>filename</replaceable> are passed to the file.</entry> </row> - <row> - <entry>ls <optional>-l</optional> - <optional><replaceable>path</replaceable></optional></entry> - <entry>Displays a listing of files in the given path, or + <row> + <entry>ls <optional>-l</optional> + <optional><replaceable>path</replaceable></optional></entry> + <entry>Displays a listing of files in the given path, or the root directory, if the path is not specified. If <option>-l</option> is specified, file sizes will also be shown.</entry> </row> - <row> - <entry>lsdev - <optional>-v</optional></entry> - <entry>Lists all of the devices from which it may be + <row> + <entry>lsdev <optional>-v</optional></entry> + <entry>Lists all of the devices from which it may be possible to load modules. If <option>-v</option> is specified, more details are printed.</entry> </row> - <row> - <entry>lsmod - <optional>-v</optional></entry> - <entry>Displays loaded modules. If <option>-v</option> + <row> + <entry>lsmod <optional>-v</optional></entry> + <entry>Displays loaded modules. If <option>-v</option> is specified, more details are shown.</entry> </row> - <row> - <entry>more <replaceable>filename</replaceable></entry> - <entry>Displays the files specified, with a pause at each - <varname>LINES</varname> displayed.</entry> - </row> - - <row> - <entry>reboot</entry> - <entry>Immediately reboots the system.</entry> - </row> - - <row> - <entry>set <replaceable>variable</replaceable>, set - <replaceable>variable</replaceable>=<replaceable>value</replaceable></entry> - <entry>Sets the specified environment variables.</entry> - </row> - - <row> - <entry>unload</entry> - <entry>Removes all loaded modules.</entry> + <row> + <entry>more <replaceable>filename</replaceable></entry> + <entry>Displays the files specified, with a pause at + each <varname>LINES</varname> displayed.</entry> + </row> + + <row> + <entry>reboot</entry> + <entry>Immediately reboots the system.</entry> + </row> + + <row> + <entry>set <replaceable>variable</replaceable>, set + <replaceable>variable</replaceable>=<replaceable>value</replaceable></entry> + <entry>Sets the specified environment variables.</entry> + </row> + + <row> + <entry>unload</entry> + <entry>Removes all loaded modules.</entry> </row> </tbody> </tgroup> - </table> + </table> - <para>Here are some practical examples of - loader usage. To boot the usual kernel in single-user - mode<indexterm><primary>single-user - mode</primary></indexterm>:</para> + <para>Here are some practical examples of loader usage. To boot + the usual kernel in single-user mode + <indexterm><primary>single-user + mode</primary></indexterm>:</para> - <screen><userinput>boot -s</userinput></screen> + <screen><userinput>boot -s</userinput></screen> - <para>To unload the usual kernel and modules and then - load the previous or another, specified kernel:</para> + <para>To unload the usual kernel and modules and then load the + previous or another, specified kernel:</para> - <screen><userinput>unload</userinput> + <screen><userinput>unload</userinput> <userinput>load <replaceable>kernel.old</replaceable></userinput></screen> - <para>Use <filename>kernel.GENERIC</filename> to refer to - the default kernel that comes with an installation, or - <filename>kernel.old</filename><indexterm> - <primary><filename>kernel.old</filename></primary></indexterm> - to refer to the previously installed kernel before a - system upgrade or before configuring a custom - kernel.</para> + <para>Use <filename>kernel.GENERIC</filename> to refer to the + default kernel that comes with an installation, or + <filename>kernel.old</filename><indexterm><primary><filename>kernel.old</filename></primary></indexterm> + to refer to the previously installed kernel before a system + upgrade or before configuring a custom kernel.</para> - <para>Use the following to load the usual modules with - another kernel:</para> + <para>Use the following to load the usual modules with another + kernel:</para> - <screen><userinput>unload</userinput> + <screen><userinput>unload</userinput> <userinput>set kernel="<replaceable>kernel.old</replaceable>"</userinput> <userinput>boot-conf</userinput></screen> - <para>To load an automated kernel configuration - script:</para> + <para>To load an automated kernel configuration script:</para> - <screen><userinput>load -t userconfig_script <replaceable>/boot/kernel.conf</replaceable></userinput></screen> + <screen><userinput>load -t userconfig_script <replaceable>/boot/kernel.conf</replaceable></userinput></screen> <indexterm> <primary>kernel</primary> @@ -472,163 +468,168 @@ boot:</screen> </indexterm> </sect2> - <sect2 xml:id="boot-init"> - <title>Last Stage</title> + <sect2 xml:id="boot-init"> + <title>Last Stage</title> - <indexterm> - <primary>&man.init.8;</primary> - </indexterm> - <para>Once the kernel is loaded by either <application>loader</application> or - by <application>boot2</application>, which bypasses - <application>loader</application>, it examines any boot - flags and adjusts its behavior as necessary. <xref + <indexterm> + <primary>&man.init.8;</primary> + </indexterm> + + <para>Once the kernel is loaded by either + <application>loader</application> or by + <application>boot2</application>, which bypasses + <application>loader</application>, it examines any boot flags + and adjusts its behavior as necessary. <xref linkend="boot-kernel"/> lists the commonly used boot flags. - Refer to &man.boot.8; for more information on the other - boot flags.</para> + Refer to &man.boot.8; for more information on the other boot + flags.</para> <indexterm> <primary>kernel</primary> <secondary>bootflags</secondary> </indexterm> - <table xml:id="boot-kernel" frame="none" pgwide="1"> - <title>Kernel Interaction During Boot</title> + <table xml:id="boot-kernel" frame="none" pgwide="1"> + <title>Kernel Interaction During Boot</title> - <tgroup cols="2"> - <thead> - <row> - <entry>Option</entry> - <entry>Description</entry> - </row> - </thead> - - <tbody> - <row> - <entry><option>-a</option></entry> - <entry>During kernel initialization, ask for the device - to mount as the root file system.</entry> - </row> - - <row> - <entry><option>-C</option></entry> - <entry>Boot the root file system from a <acronym>CDROM</acronym>.</entry> - </row> - - <row> - <entry><option>-s</option></entry> - <entry>Boot into single-user mode.</entry> - </row> - - <row> - <entry><option>-v</option></entry> - <entry>Be more verbose during kernel startup.</entry> - </row> - </tbody> - </tgroup> - </table> - - <para>Once the kernel has finished booting, it passes control to - the user process &man.init.8;, which is located at - <filename>/sbin/init</filename>, or the program path specified - in the <envar>init_path</envar> variable in - <command>loader</command>. This is the last stage of the boot - process.</para> + <tgroup cols="2"> + <thead> + <row> + <entry>Option</entry> + <entry>Description</entry> + </row> + </thead> - <para>The boot sequence makes sure that the file systems available - on the system are consistent. If a <acronym>UFS</acronym> file - system is not, and <command>fsck</command> - cannot fix the inconsistencies, - <application>init</application> drops the system into single-user mode so that the - system administrator can resolve the problem directly. Otherwise, - the system boots into multi-user mode.</para> - - <sect3 xml:id="boot-singleuser"> - <title>Single-User Mode</title> - - <indexterm><primary>single-user mode</primary></indexterm> - <indexterm><primary>console</primary></indexterm> - - <para>A user can specify this mode by - booting with <option>-s</option>, or by - setting the <envar>boot_ single</envar> variable in - <application>loader</application>. It can also be reached by - running <command>shutdown now</command> from - multi-user mode. Single-user mode begins with this message:</para> + <tbody> + <row> + <entry><option>-a</option></entry> + <entry>During kernel initialization, ask for the device + to mount as the root file system.</entry> + </row> + + <row> + <entry><option>-C</option></entry> + <entry>Boot the root file system from a + <acronym>CDROM</acronym>.</entry> + </row> + + <row> + <entry><option>-s</option></entry> + <entry>Boot into single-user mode.</entry> + </row> + + <row> + <entry><option>-v</option></entry> + <entry>Be more verbose during kernel startup.</entry> + </row> + </tbody> + </tgroup> + </table> + + <para>Once the kernel has finished booting, it passes control to + the user process &man.init.8;, which is located at + <filename>/sbin/init</filename>, or the program path specified + in the <envar>init_path</envar> variable in + <command>loader</command>. This is the last stage of the boot + process.</para> + + <para>The boot sequence makes sure that the file systems + available on the system are consistent. If a + <acronym>UFS</acronym> file system is not, and + <command>fsck</command> cannot fix the inconsistencies, + <application>init</application> drops the system into + single-user mode so that the system administrator can resolve + the problem directly. Otherwise, the system boots into + multi-user mode.</para> + + <sect3 xml:id="boot-singleuser"> + <title>Single-User Mode</title> + + <indexterm><primary>single-user mode</primary></indexterm> + <indexterm><primary>console</primary></indexterm> + + <para>A user can specify this mode by booting with + <option>-s</option>, or by setting the <envar>boot + _ single</envar> variable in + <application>loader</application>. It can also be reached + by running <command>shutdown now</command> from multi-user + mode. Single-user mode begins with this message:</para> <programlisting>Enter full pathname of shell or RETURN for /bin/sh:</programlisting> - <para>If the user presses <keycap>Enter</keycap>, the system - will enter the default Bourne shell. To specify a different - shell, input the full path to the shell.</para> - - <para>Single-user mode is usually used to repair a system that will not - boot due to an inconsistent file system or an error in a boot - configuration file. It can also be used to reset the - <systemitem class="username">root</systemitem> password when - it is unknown. These actions are possible as the single-user - mode prompt gives full, local access to the system and its - configuration files. There is no networking in this mode.</para> - - <para>While single-user mode is useful for repairing a system, - it poses a security risk unless the system is in a physically - secure location. By default, any user who can gain physical - access to a system will have full control of that system after - booting into single-user mode.</para> - - <para>If the system <literal>console</literal> is changed to - <literal>insecure</literal> in <filename>/etc/ttys</filename>, - the system will first prompt for the <systemitem - class="username">root</systemitem> password before - initiating single-user mode. This adds a measure of security - while removing the ability to reset the <systemitem - class="username">root</systemitem> password when it is - unknown.</para> - - <example xml:id="boot-insecure-console"> - <title>Configuring an Insecure Console in - <filename>/etc/ttys</filename></title> + <para>If the user presses <keycap>Enter</keycap>, the system + will enter the default Bourne shell. To specify a different + shell, input the full path to the shell.</para> + + <para>Single-user mode is usually used to repair a system that + will not boot due to an inconsistent file system or an error + in a boot configuration file. It can also be used to reset + the <systemitem class="username">root</systemitem> password + when it is unknown. These actions are possible as the + single-user mode prompt gives full, local access to the + system and its configuration files. There is no networking + in this mode.</para> + + <para>While single-user mode is useful for repairing a system, + it poses a security risk unless the system is in a + physically secure location. By default, any user who can + gain physical access to a system will have full control of + that system after booting into single-user mode.</para> + + <para>If the system <literal>console</literal> is changed to + <literal>insecure</literal> in + <filename>/etc/ttys</filename>, the system will first prompt + for the <systemitem class="username">root</systemitem> + password before initiating single-user mode. This adds a + measure of security while removing the ability to reset the + <systemitem class="username">root</systemitem> password when + it is unknown.</para> + + <example xml:id="boot-insecure-console"> + <title>Configuring an Insecure Console in + <filename>/etc/ttys</filename></title> - <programlisting># name getty type status comments + <programlisting># name getty type status comments # # If console is marked "insecure", then init will ask for the root password # when going to single-user mode. console none unknown off <replaceable>insecure</replaceable></programlisting> - </example> + </example> <para>An <literal>insecure</literal> console means that physical security to the console is considered to be insecure, so only someone who knows the <systemitem class="username">root</systemitem> password may use single-user mode.</para> - </sect3> + </sect3> - <sect3 xml:id="boot-multiuser"> - <title>Multi-User Mode</title> + <sect3 xml:id="boot-multiuser"> + <title>Multi-User Mode</title> - <indexterm><primary>multi-user mode</primary></indexterm> + <indexterm><primary>multi-user mode</primary></indexterm> - <para>If <application>init</application> finds the file systems to be in order, or - once the user has finished their commands in single-user mode - and has typed <command>exit</command> to leave single-user mode, - the system enters - multi-user mode, in which it starts the resource configuration - of the system.</para> - - <indexterm><primary>rc files</primary></indexterm> - - <para>The resource configuration system reads in configuration - defaults from <filename>/etc/defaults/rc.conf</filename> and - system-specific details from - <filename>/etc/rc.conf</filename>. It then proceeds to mount - the system file systems listed in - <filename>/etc/fstab</filename>. It starts up networking - services, miscellaneous system daemons, then the startup - scripts of locally installed packages.</para> - - <para>To learn more about the resource configuration system, - refer to &man.rc.8; and examine the scripts located in - <filename>/etc/rc.d</filename>.</para> - </sect3> + <para>If <application>init</application> finds the file + systems to be in order, or once the user has finished their + commands in single-user mode and has typed + <command>exit</command> to leave single-user mode, the + system enters multi-user mode, in which it starts the + resource configuration of the system.</para> + + <indexterm><primary>rc files</primary></indexterm> + + <para>The resource configuration system reads in configuration + defaults from <filename>/etc/defaults/rc.conf</filename> and + system-specific details from + <filename>/etc/rc.conf</filename>. It then proceeds to + mount the system file systems listed in + <filename>/etc/fstab</filename>. It starts up networking + services, miscellaneous system daemons, then the startup + scripts of locally installed packages.</para> + + <para>To learn more about the resource configuration system, + refer to &man.rc.8; and examine the scripts located in + <filename>/etc/rc.d</filename>.</para> + </sect3> </sect2> </sect1> <!-- @@ -638,9 +639,9 @@ console none <para> </para> </sect2> --> - <sect1 xml:id="boot-splash"> - <info> - <title>Configuring Boot Time Splash Screens</title> + <sect1 xml:id="boot-splash"> + <info> + <title>Configuring Boot Time Splash Screens</title> <authorgroup> <author> @@ -653,122 +654,117 @@ console none </authorgroup> </info> - <para>Typically when a &os; system boots, it displays its - progress as a series of messages at the console. A boot splash - screen creates an alternate boot screen that - hides all of the boot probe and service - startup messages. A few boot loader messages, including the boot options - menu and a timed wait countdown prompt, are displayed at - boot time, even when the splash screen is enabled. The display of the splash screen - can be turned off by hitting any - key on the keyboard during the boot process.</para> - - <para>There are two basic environments available in &os;. The - first is the default legacy virtual console command line - environment. After the system finishes booting, a console - login prompt is presented. The second environment is a configured - graphical environment. Refer to <xref linkend="x11"/> - for more information on how to install - and configure a graphical display manager and a graphical - login manager.</para> - - <para>Once the system has booted, the splash screen defaults to being a screen saver. - After a time period of non-use, the splash screen - will display and will cycle through steps of changing - intensity of the image, from bright to very dark and over - again. The configuration of the splash screen saver can be - overridden by adding a <literal>saver=</literal> line to - <filename>/etc/rc.conf</filename>. Several built-in screen - savers are available and described in &man.splash.4;. The - <literal>saver=</literal> option only applies to virtual - consoles and has no effect on graphical display - managers.</para> - - <para>Sample splash screen files can be downloaded from the - gallery at <link - xlink:href="http://artwork.freebsdgr.org/node/3/">http://artwork.freebsdgr.org</link>. - By installing the - <package>sysutils/bsd-splash-changer</package> package or port, a random splash - image from a collection will display at - boot.</para> - - <para>The splash screen function supports 256-colors in the - bitmap (<filename>.bmp</filename>), ZSoft - <acronym>PCX</acronym> (<filename>.pcx</filename>), or - TheDraw (<filename>.bin</filename>) formats. The <filename>.bmp</filename>, - <filename>.pcx</filename>, or <filename>.bin</filename> image - has to be placed on the root partition, for example in - <filename>/boot</filename>. The splash image - files must have a resolution of 320 by 200 pixels or less in - order to work on standard <acronym>VGA</acronym> adapters. - For the default boot display resolution of 256-colors and - 320 by 200 pixels or less, add the following lines to - <filename>/boot/loader.conf</filename>. - Replace <replaceable>splash.bmp</replaceable> with the name of - the bitmap file to use:</para> + <para>Typically when a &os; system boots, it displays its progress + as a series of messages at the console. A boot splash screen + creates an alternate boot screen that hides all of the boot + probe and service startup messages. A few boot loader messages, + including the boot options menu and a timed wait countdown + prompt, are displayed at boot time, even when the splash screen + is enabled. The display of the splash screen can be turned off + by hitting any key on the keyboard during the boot + process.</para> + + <para>There are two basic environments available in &os;. The + first is the default legacy virtual console command line + environment. After the system finishes booting, a console login + prompt is presented. The second environment is a configured + graphical environment. Refer to <xref linkend="x11"/> for more + information on how to install and configure a graphical display + manager and a graphical login manager.</para> + + <para>Once the system has booted, the splash screen defaults to + being a screen saver. After a time period of non-use, the + splash screen will display and will cycle through steps of + changing intensity of the image, from bright to very dark and + over again. The configuration of the splash screen saver can be + overridden by adding a <literal>saver=</literal> line to + <filename>/etc/rc.conf</filename>. Several built-in screen + savers are available and described in &man.splash.4;. The + <literal>saver=</literal> option only applies to virtual + consoles and has no effect on graphical display managers.</para> + + <para>Sample splash screen files can be downloaded from the + gallery at <link + xlink:href="http://artwork.freebsdgr.org/node/3/">http://artwork.freebsdgr.org</link>. + By installing the <package>sysutils/bsd-splash-changer</package> + package or port, a random splash image from a collection will + display at boot.</para> + *** DIFF OUTPUT TRUNCATED AT 1000 LINES ***
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