Expand Grub details and add a warning.

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@2987 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

1 files changed, 38 insertions, 4 deletions

diff --git a/chapter08/grub.xml b/chapter08/grub.xml
index af69909b6..4198a94d0 100644
--- a/chapter08/grub.xml
+++ b/chapter08/grub.xml
@@ -2,9 +2,30 @@
 <title>Making the LFS system bootable</title>
 <?dbhtml filename="grub.html" dir="chapter08"?>
 
-<para>Now that we have our shiny new Linux-From-Scratch system completed,
-we need to ensure we can boot it.  To do this, we will run the
-<userinput>grub</userinput> program.</para>
+<para>Your shiny new LFS system is almost complete. One of the last things to
+do is ensure you can boot it. The instructions below apply only to computers
+of IA-32 architecture, i.e. mainstream PC's. Information on "boot loading" for
+other architectures should be available in the usual resource specific
+locations for those architectures.</para>
+
+<para>Boot loading can be a complex area. First, a few cautionary words. You
+really should be familiar with your current boot loader and any other
+operating systems present on your hard drive(s) that you might wish to keep
+bootable. Please make sure that you have an emergency boot disk ready, so that
+you can rescue your computer if, by any chance, your computer becomes unusable
+(unbootable).</para>
+
+<para>Earlier, we compiled and installed the Grub boot loader software in
+preparation for this step. The procedure involves writing some special Grub
+files to specific locations on the hard drive. Before we get to that, we
+highly recommend that you create a Grub boot floppy diskette just in case.
+Insert a blank floppy diskette and run the following commands:</para>
+
+<screen><userinput>dd if=/boot/grub/stage1 of=/dev/fd0 bs=512 count=1
+dd if=/boot/grub/stage2 of=/dev/fd0 bs=512 seek=1</userinput></screen>
+
+<para>Remove the diskette and store it somewhere safe. Now we'll run the
+<userinput>grub</userinput> shell.</para>
 
 <screen><userinput>grub</userinput></screen>
 
@@ -26,13 +47,26 @@ files -- you can use Tab everywhere to make Grub show the alternatives:</para>
 
 <screen><userinput>root (hd0,3)</userinput></screen>
 
+<!-- HACK - Force some whitespace to appease tidy -->
+<literallayout></literallayout>
+
+<warning><para>The following command will overwrite your current boot loader.
+Don't run the command if this is not what you want. For example, you may be
+using a third party boot manager to manage your MBR (Master Boot Record). In
+this scenario, it would probably make more sense to install Grub into the
+"boot sector" of the LFS partition, in which case the command would become
+<userinput>setup (hd0,3)</userinput>:</para></warning>
+
+<!-- HACK - Force some whitespace to appease tidy -->
+<literallayout></literallayout>
+
 <para>Then tell it to install itself into the MBR (Master Boot Record) of
 <filename>hda</filename>:</para>
 
 <screen><userinput>setup (hd0)</userinput></screen>
 
 <para>If all is well, Grub will have reported finding its files in
-<filename>/boot/grub</filename>. That's all there was to it:</para>
+<filename>/boot/grub</filename>. That's all there is to it:</para>
 
 <screen><userinput>quit</userinput></screen>