ref-manual, yocto-project-qs, poky.ent: Fixed CentOS essentials

Fixes [YOCTO #10854]

I added extra "yum" commands and a make command to deal with
some essential packages needed for CentOS distribution.  These
packages were missing.

(From yocto-docs rev: 38ac6cf0165f7dd7bbfd583e218b6948dafae29c)

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

1 files changed, 22 insertions, 2 deletions

diff --git a/documentation/ref-manual/introduction.xml b/documentation/ref-manual/introduction.xml
index ddf6a860eb..cec23b6039 100644
--- a/documentation/ref-manual/introduction.xml
+++ b/documentation/ref-manual/introduction.xml
@@ -368,8 +368,28 @@
                         Packages needed to build an image for a headless
                         system:
                         <literallayout class='monospaced'>
-     $ sudo yum install &CENTOS_HOST_PACKAGES_ESSENTIAL;
-                        </literallayout></para></listitem>
+     $ sudo yum install &CENTOS_HOST_PACKAGES_ESSENTIAL; SDL-devel xterm
+                        </literallayout>
+                        <note><title>Notes</title>
+                            <itemizedlist>
+                                <listitem><para>
+                                    Extra Packages for Enterprise Linux
+                                    (i.e. <filename>epel-release</filename>)
+                                    is a collection of packages from Fedora
+                                    built on RHEL/CentOS for easy installation
+                                    of packages not included in enterprise
+                                    Linux by default.
+                                    You need to install these packages
+                                    separately.
+                                    </para></listitem>
+                                <listitem><para>
+                                    The <filename>makecache</filename> command
+                                    consumes additional Metadata from
+                                    <filename>epel-release</filename>.
+                                    </para></listitem>
+                            </itemizedlist>
+                        </note>
+                        </para></listitem>
                     <listitem><para><emphasis>Graphical and Eclipse Plug-In Extras:</emphasis>
                         Packages recommended if the host system has graphics
                         support or if you are going to use the Eclipse