overview-manual, ref-manual: Moved introductory material to overview manual

Fixes [YOCTO #12370]

Moved an introductory section for YP that was in the ref-manual
to the beginning of the YP environment chapter of the overview-manual.
Had to move a figure and update the makefile as well as adjust some
links.

(From yocto-docs rev: 8ec45f945a21b1f64e7529b95df6b5fb21e87449)

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

2 files changed, 117 insertions, 0 deletions

diff --git a/documentation/overview-manual/figures/YP-flow-diagram.png b/documentation/overview-manual/figures/YP-flow-diagram.png
new file mode 100644
index 0000000000..8264410504
--- /dev/null
+++ b/documentation/overview-manual/figures/YP-flow-diagram.png
diff --git a/documentation/overview-manual/overview-development-environment.xml b/documentation/overview-manual/overview-development-environment.xml
index 32fe1816ab..d34f35ec88 100644
--- a/documentation/overview-manual/overview-development-environment.xml
+++ b/documentation/overview-manual/overview-development-environment.xml
@@ -21,6 +21,123 @@
     syntax.
 </para>
 
+<section id='yp-intro'>
+    <title>Introduction</title>
+
+    <para>
+        The Yocto Project is an open-source collaboration project whose
+        focus is for developers of embedded Linux systems.
+        Among other things, the Yocto Project uses an
+        <ulink url='&YOCTO_DOCS_REF_URL;#build-system-term'>OpenEmbedded build system</ulink>.
+        The build system, which is based on the OpenEmbedded (OE) project and
+        uses the
+        <ulink url='&YOCTO_DOCS_REF_URL;#bitbake-term'>BitBake</ulink> tool,
+        constructs complete Linux images for architectures based on ARM, MIPS,
+        PowerPC, x86 and x86-64.
+        <note>
+            Historically, the OpenEmbedded build system, which is the
+            combination of BitBake and OE components, formed a reference
+            build host that was known as
+            "<ulink url='&YOCTO_DOCS_REF_URL;#poky'>Poky</ulink>"
+            (<emphasis>Pah</emphasis>-kee).
+            The term "Poky", as used throughout the Yocto Project Documentation
+            set, can have different meanings.
+        </note>
+        The Yocto Project provides various ancillary tools for the embedded
+        developer and also features the Sato reference User Interface, which
+        is optimized for stylus-driven, low-resolution screens.
+    </para>
+
+    <mediaobject>
+        <imageobject>
+            <imagedata fileref="figures/YP-flow-diagram.png"
+                format="PNG" align='center' width="8in"/>
+        </imageobject>
+    </mediaobject>
+
+    <para>
+        Here are some highlights for the Yocto Project:
+    </para>
+
+    <itemizedlist>
+        <listitem><para>
+            Provides a recent Linux kernel along with a set of system
+            commands and libraries suitable for the embedded
+            environment.
+            </para></listitem>
+        <listitem><para>
+            Makes available system components such as X11, GTK+, Qt,
+            Clutter, and SDL (among others) so you can create a rich user
+            experience on devices that have display hardware.
+            For devices that do not have a display or where you wish to
+            use alternative UI frameworks, these components need not be
+            installed.
+            </para></listitem>
+        <listitem><para>
+            Creates a focused and stable core compatible with the
+            OpenEmbedded project with which you can easily and reliably
+            build and develop.
+            </para></listitem>
+        <listitem><para>
+            Fully supports a wide range of hardware and device emulation
+            through the Quick EMUlator (QEMU).
+            </para></listitem>
+        <listitem><para>
+            Provides a layer mechanism that allows you to easily extend
+            the system, make customizations, and keep them organized.
+            </para></listitem>
+    </itemizedlist>
+
+    <para>
+        You can use the Yocto Project to generate images for many kinds
+        of devices.
+        As mentioned earlier, the Yocto Project supports creation of
+        reference images that you can boot within and emulate using QEMU.
+        The standard example machines target QEMU full-system
+        emulation for 32-bit and 64-bit variants of x86, ARM, MIPS, and
+        PowerPC architectures.
+        Beyond emulation, you can use the layer mechanism to extend
+        support to just about any platform that Linux can run on and that
+        a toolchain can target.
+    </para>
+
+    <para>
+        Another Yocto Project feature is the Sato reference User
+        Interface.
+        This optional UI that is based on GTK+ is intended for devices with
+        restricted screen sizes and is included as part of the
+        OpenEmbedded Core layer so that developers can test parts of the
+        software stack.
+    </para>
+
+    <para>
+        While the Yocto Project does not provide a strict testing framework,
+        it does provide or generate for you artifacts that let you perform
+        target-level and emulated testing and debugging.
+        Additionally, if you are an
+        <trademark class='trade'>Eclipse</trademark> IDE user, you can
+        install an Eclipse Yocto Plug-in to allow you to develop within that
+        familiar environment.
+    </para>
+
+    <para>
+        By default, using the Yocto Project to build an image creates a Poky
+        distribution.
+        However, you can create your own distribution by providing key
+        <ulink url='&YOCTO_DOCS_REF_URL;#metadata'>Metadata</ulink>.
+        A good example is Angstrom, which has had a distribution
+        based on the Yocto Project since its inception.
+        Other examples include commercial distributions like
+        <ulink url='https://www.yoctoproject.org/organization/wind-river-systems'>Wind River Linux</ulink>,
+        <ulink url='https://www.yoctoproject.org/organization/mentor-graphics'>Mentor Embedded Linux</ulink>,
+        <ulink url='https://www.yoctoproject.org/organization/enea-ab'>ENEA Linux</ulink>
+        and <ulink url='https://www.yoctoproject.org/ecosystem/member-organizations'>others</ulink>.
+        See the "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-your-own-distribution'>Creating Your Own Distribution</ulink>"
+        section in the Yocto Project Development Tasks Manual for more
+        information.
+    </para>
+</section>
+
 <section id='open-source-philosophy'>
     <title>Open Source Philosophy</title>