LDP/LDP/guide/docbook/Linux-Filesystem-Hierarchy/boot.xml

<sect1 id="boot">
  <title>/boot</title>

  <para>This directory contains everything required for the boot process
  except for configuration files not needed at boot time (the most notable
  of those being those that belong to the GRUB boot-loader) and the map 
  installer. Thus, the /boot directory stores data that is used before 
  the kernel begins executing user-mode programs. This may include redundant 
  (back-up) master boot records, sector/system map files, the kernel and 
  other important boot files and data that is not directly edited by hand.
  Programs necessary to arrange for the boot loader to be able to boot a 
  file are placed in /sbin. Configuration files for boot loaders are placed 
  in /etc. The system kernel is located in either / or /boot (or as under 
  Debian in /boot but is actually a symbolically linked at / in accordance
  with the FSSTND).</para>

  <para><variablelist><varlistentry><term>/boot/boot.0300</term><listitem><para>Backup
  master boot record.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/boot.b</term><listitem><para>This
  is installed as the basic boot sector. In the case of most modern
  distributions it is actually a symbolic link to one of four files
  /boot/boot-bmp.b, /boot/boot-menu.b, /boot/boot-text.b, /boot/boot-compat.b
  which allow a user to change the boot-up schema so that it utilises a splash
  screen, a simple menu, a text based interface or a minimal boot loader to
  ensure compatibility respectively. In each case re-installation of lilo is
  necessary in order to complete the changes. To change the actual
  &#39;boot-logo&#39; you can either use utilities such as fblogo or the more
  refined bootsplash.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/chain.b</term><listitem><para>Used
  to boot non-Linux operating systems.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/config-kernel-version</term><listitem><para>Installed
  kernel configuration. This file is most useful when compiling kernels on
  other systems or device modules. Below is a small sample of what the
  contents of the file looks like.</para>
  
  <para><screen>
        CONFIG_X86=y
        CONFIG_MICROCODE=m
        CONFIG_X86_MSR=m
        CONFIG_MATH_EMULATION=y
        CONFIG_MTRR=y
        CONFIG_MODULES=y
        CONFIG_MODVERSIONS=y
        CONFIG_SCSI_DEBUG=m
        CONFIG_I2O=m
        CONFIG_ARCNET_ETH=y
        CONFIG_FMV18X=m
        CONFIG_HPLAN_PLUS=m
        CONFIG_ETH16I=m
        CONFIG_NE2000=m
        CONFIG_HISAX_HFC_PCI=y
        CONFIG_ISDN_DRV_AVMB1_C4=m
        CONFIG_USB_RIO500=m
        CONFIG_QUOTA=y
        CONFIG_AUTOFS_FS=m
        CONFIG_ADFS_FS=m
        CONFIG_AFFS_FS=m
        CONFIG_HFS_FS=m
        CONFIG_FAT_FS=y
        CONFIG_MSDOS_FS=y
        CONFIG_UMSDOS_FS=m
        CONFIG_FBCON_VGA=m
        CONFIG_FONT_8x8=y
        CONFIG_FONT_8x16=y
        CONFIG_SOUND=m
        CONFIG_SOUND_CMPCI=m
        CONFIG_AEDSP16=m
  </screen></para>
			
  <para>As you can see, it's rather
  simplistic. The line begins with the configuration option and whether it's
  configured as part of the kernel, as a module or not at all. Lines beginning
  with a # symbol are comments and are not interpreted during processing.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/os2_d.b</term><listitem><para>Used
  to boot to the 0S/2 operating system.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/map</term><listitem><para>Contains
  the location of the kernel.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/vmlinuz, /boot/vmlinuz-kernel-version</term><listitem><para>Normally the kernel or
  symbolic link to the kernel.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/grub</term><listitem><para>This
  subdirectory contains the GRUB configuration files including boot-up images
  and sounds. GRUB is the GNU GRand Unified Bootloader, a project which
  intends to solve all bootup problems once and for all. One of the most
  interesting features, is that you don&#39;t have to install a new partition
  or kernel, you can change all parameters at boot time via the GRUB Console,
  since it knows about the filesystems.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/grub/device.map</term><listitem><para>Maps
  devices in /dev to those used by grub. For example, (/dev/fd0) is
  represented by /dev/fd0 and (hd0, 4) is referenced by /dev/hda5.</para></listitem>
  
  </varlistentry><varlistentry><term>/boot/grub/grub.conf,
  /boot/grub/menu.lst</term><listitem><para>Grub configuration file.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/grub/messages</term><listitem><para>Grub
  boot-up welcome message.</para></listitem></varlistentry>
  
  <varlistentry><term>/boot/grub/splash.xpm.gz</term><listitem><para>Grub
  boot-up background image.</para></listitem></varlistentry></variablelist></para>

</sect1>