[FE training-materials-updates] yocto: slides: add information about variable precedence

[Antoine Ténart]

Repository : git://git.free-electrons.com/training-materials.git

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=08fffc9aa517a8809dfe68347fa665ae839738e9

>---------------------------------------------------------------

commit 08fffc9aa517a8809dfe68347fa665ae839738e9
Author: Antoine Tenart <antoine.tenart at free-electrons.com>
Date:   Mon Nov 24 16:58:33 2014 +0100

    yocto: slides: add information about variable precedence
    
    Signed-off-by: Antoine Tenart <antoine.tenart at free-electrons.com>


>---------------------------------------------------------------

08fffc9aa517a8809dfe68347fa665ae839738e9
 slides/yocto-advanced/yocto-advanced.tex | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/slides/yocto-advanced/yocto-advanced.tex b/slides/yocto-advanced/yocto-advanced.tex
index 3938071..419aca8 100644
--- a/slides/yocto-advanced/yocto-advanced.tex
+++ b/slides/yocto-advanced/yocto-advanced.tex
@@ -40,7 +40,7 @@
 \end{frame}
 
 \begin{frame}
-  \frametitle{Methods and conditions 1/2}
+  \frametitle{Methods and conditions 1/3}
   \begin{itemize}
     \item Append the keyword \code{_append} to a configuration
       variable to add values {\bf after} the ones previously defined
@@ -70,7 +70,7 @@
 \end{frame}
 
 \begin{frame}
-  \frametitle{Methods and conditions 2/2}
+  \frametitle{Methods and conditions 2/3}
   \begin{itemize}
     \item The previous methods can be combined.
     \item If we define:
@@ -90,6 +90,26 @@
   \end{itemize}
 \end{frame}
 
+\begin{frame}[fragile]
+  \frametitle{Methods and conditions 3/3}
+  \begin{itemize}
+    \item The most specific variable takes precedence.
+    \item Example:
+      \begin{minted}[fontsize=\footnotesize]{console}
+IMAGE_INSTALL_beaglebone = "busybox mtd-utils i2c-tools"
+IMAGE_INSTALL = "busybox mtd-utils"
+      \end{minted}
+    \item If the machine is \code{beaglebone}:
+      \begin{itemize}
+        \item \code{IMAGE_INSTALL = "busybox mtd-utils i2c-tools"}
+      \end{itemize}
+    \item Otherwise:
+      \begin{itemize}
+        \item \code{IMAGE_INSTALL = "busybox mtd-utils"}
+      \end{itemize}
+  \end{itemize}
+\end{frame}
+
 \begin{frame}
   \frametitle{Operators 1/2}
   \begin{itemize}