Expand discussion of UEFI in kernel and grub sections

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@11165 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter08/grub.xml

@@ -38,15 +38,18 @@
 grub-mkrescue --output=grub-img.iso 
 xorriso -as cdrecord -v dev=/dev/cdrw blank=as_needed grub-img.iso</userinput></screen>
 
-    <note><para>Most newer systems now come with system firmware that is in
-    UEFI (Unified Extensible Firmware Interface) mode by default. To boot LFS
-    on these systems using the instructions here, the UEFI Mode and Secure Boot
-    capabilities need to be turned off. There are ways to boot with these
-    capabilities still enabled, but then are not covered here. For details, 
-    see <ulink
-    url="http://www.linuxfromscratch.org/hints/downloads/files/lfs-uefi.txt"> 
-    the lfs-uefi.txt hint</ulink> at
-    http://www.linuxfromscratch.org/hints/downloads/files/lfs-uefi.txt.</para></note>
+    <note>
+      <para>
+        To boot LFS on host systems that have UEFI enabled, the kernel needs to
+        have been built with the CONFIG_EFI_STUB capabality described in the
+        previous section.  However, LFS can be booted using GRUB2 without such
+        an addition. To do this, the UEFI Mode and Secure Boot capabilities in
+        the host system's BIOS need to be turned off.  For details, see <ulink
+        url="http://www.linuxfromscratch.org/hints/downloads/files/lfs-uefi.txt">
+        the lfs-uefi.txt hint</ulink> at
+        http://www.linuxfromscratch.org/hints/downloads/files/lfs-uefi.txt.
+      </para>
+    </note>
 
   </sect2>
 

chapter08/kernel.xml

@@ -121,6 +121,24 @@ File systems  --->
     Index of Kernel Settings</ulink>
     (&lfs-root;blfs/view/&short-version;/longindex.html#kernel-config-index).</para>
 
+    <note>
+      <para>If your host hardware is using UEFI, then the 'make defconfig'
+      above should automatically add in some EFI-related kernel options.</para>
+
+      <para>In order to allow your LFS kernel to be booted from within your
+      host's UEFI boot environment, your kernel must have this option
+      selected:</para>
+
+<screen role="nodump">Processor type and features  ---&gt;
+   [*]   EFI stub support  [CONFIG_EFI_STUB]</screen>
+
+      <para>A fuller description of managing UEFI environments from within LFS
+      is covered by the lfs-uefi.txt hint at
+      <ulink 
+        url="http://www.linuxfromscratch.org/hints/downloads/files/lfs-uefi.txt"/>.
+      </para>
+    </note>
+
     <variablelist>
       <title>The rationale for the above configuration items:</title>