1 files changed, 69 insertions, 0 deletions
diff --git a/distribution/yocto-advanced/yocto-layers.tex b/distribution/yocto-advanced/yocto-layers.tex
new file mode 100644
index 0000000..1c6dc53
--- /dev/null
+++ b/distribution/yocto-advanced/yocto-layers.tex
@@ -0,0 +1,69 @@
+\subsection{Using BSP layers}
+
+\begin{frame}[fragile]
+\frametitle{folder layout}
+\begin{verbatim}
+meta-mylayer
++ conf
+|  + layer.conf
++ classes
+|  + class1.bbclass
+|  + class2.bbclass
++ recipes-category1
+|  + package-1
+|      + package-1.bb
+|  + package-2
+|      + package-2.bb
++ recipes-category2
+| ..
+\end{verbatim}
+\end{frame}
+
+\begin{frame}[fragile]
+	\frametitle{meta-*/conf/layer.conf}
+	each layer needs a configuration file
+	\begin{itemize}
+		\item add conf and class directories to BBPATH
+			\begin{verbatim}BBPATH =. "${LAYERDIR}"\end{verbatim}
+		\item add recipe directories to BBFILES
+			\begin{verbatim}BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
+			${LAYERDIR}/recipes-*/*/*.bbappend"\end{verbatim}
+		\item add layer name to BBFILE\_COLLECTIONS
+			\begin{verbatim}BBFILE_COLLECTIONS += "mylayer"\end{verbatim}
+		\item set root of the layer
+			\begin{verbatim}BBFILE_PATTERN_mylayer = "^${LAYERDIR}/"\end{verbatim}
+		\item set default priority of the layer
+			\begin{verbatim}BBFILE_PRIORITY_mylayer = "5"\end{verbatim}
+		\item set version of layer (only increment if dependencies with other
+			layers are affected)
+			\begin{verbatim}LAYERVERSION_mylayer = "2"\end{verbatim}
+		\item set dependencies to other layers
+			\begin{verbatim}LAYERDEPENDS_mylayer = "meta-yocto"\end{verbatim}
+	\end{itemize}
+\end{frame}
+
+\begin{frame}
+\frametitle{bitbake-layers}
+is useful to debug relations between different layers, options are:
+\begin{description}
+\item [show-layers] shows the current configured layers
+\item [show-recipes] lists available recipes and the layers that provide them.
+\item [show-overlayed] lists overlayed recipes
+\item [show-appends] lists .bbappend files
+	and the recipe files to which they apply
+\item [show-cross-depends] lists dependency relationships
+	between recipes that cross layer boundaries
+\item [flatten] flattens the layer configuration
+	into a separate output directory.
+\end{description}
+\end{frame}
+
+\begin{frame}
+\frametitle{definitions}
+\begin{itemize}
+	\item It is possible for a recipe with a lower version number PV in a layer
+that has a higher priority to take precedence.
+	\item Also, the layer priority does not currently affect the precedence
+order of .conf or .bbclass files. Future versions of BitBake might address this.
+\end{itemize}
+\end{frame}