ref-manual: Updated image-live.bbclass description

Fixes [YOCTO #9001]

Updated the image-live class description to specifically mention
creating *.iso and *.hddimg images as "live" images.  Provided more
explanation about usage through the NOISO and NOHDD variables.

Also, provided a cross-referencing link back to the updated
image-live class from the EFI_PROVIDERS variable.

(From yocto-docs rev: 788061b2911339c8396b798a0ab5635ab5bb89e1)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 16 insertions, 6 deletions

diff --git a/documentation/ref-manual/ref-classes.xml b/documentation/ref-manual/ref-classes.xml
index fc0314b957..16af6f9d07 100644
--- a/documentation/ref-manual/ref-classes.xml
+++ b/documentation/ref-manual/ref-classes.xml
@@ -1301,19 +1301,27 @@
     <title><filename>image-live.bbclass</filename></title>
 
     <para>
-        The <filename>image-live</filename> class supports building "live"
-        images.
+        This class controls building "live" (i.e. HDDIMG and ISO) images.
+        Live images contain syslinux for legacy booting, as well as the
+        bootloader specified by
+        <link linkend='var-EFI_PROVIDER'><filename>EFI_PROVIDER</filename></link>
+        if
+        <link linkend='var-MACHINE_FEATURES'><filename>MACHINE_FEATURES</filename></link>
+        contains "efi".
     </para>
 
     <para>
         Normally, you do not use this class directly.
         Instead, you add "live" to
         <link linkend='var-IMAGE_FSTYPES'><filename>IMAGE_FSTYPES</filename></link>.
+        You can selectively build just one of these types through the
+        <link linkend='var-NOISO'><filename>NOISO</filename></link>
+        and
+        <link linkend='var-NOHDD'><filename>NOHDD</filename></link> variables.
         For example, if you were building an ISO image, you would add "live"
         to <filename>IMAGE_FSTYPES</filename>, set the
-        <link linkend='var-NOISO'><filename>NOISO</filename></link> variable to
-        "0" and the build system would use the <filename>image-live</filename>
-        class to build the ISO image.
+        <filename>NOISO</filename> variable to "0" and the build system would
+        use the <filename>image-live</filename> class to build the ISO image.
     </para>
 </section>
 
diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index be509c4a81..94558df4b9 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -3880,7 +3880,9 @@
                 <para>
                     See the
                     <link linkend='ref-classes-systemd-boot'><filename>systemd-boot</filename></link>
-                    class for more information.
+                    and
+                    <link linkend='ref-classes-image-live'><filename>image-live</filename></link>
+                    classes for more information.
                 </para>
             </glossdef>
         </glossentry>