[FE training-materials-updates] yocto: slides: add a slide about the toolchain selection

[Antoine Ténart]

Repository : git://git.free-electrons.com/training-materials.git
On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=93537fc2966f09aafbe5e721848a9899387e523b

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

commit 93537fc2966f09aafbe5e721848a9899387e523b
Author: Antoine Tenart <antoine.tenart at free-electrons.com>
Date:   Thu Mar 24 11:37:38 2016 +0100

    yocto: slides: add a slide about the toolchain selection
    
    Signed-off-by: Antoine Tenart <antoine.tenart at free-electrons.com>


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

93537fc2966f09aafbe5e721848a9899387e523b
 slides/yocto-layer-distro/yocto-layer-distro.tex | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/slides/yocto-layer-distro/yocto-layer-distro.tex b/slides/yocto-layer-distro/yocto-layer-distro.tex
index ffddf6e..c3aad1f 100644
--- a/slides/yocto-layer-distro/yocto-layer-distro.tex
+++ b/slides/yocto-layer-distro/yocto-layer-distro.tex
@@ -60,3 +60,22 @@ MAINTAINER = "..."
     \end{minted}
   \end{block}
 \end{frame}
+
+\begin{frame}
+  \frametitle{Toolchain selection}
+  \begin{itemize}
+    \item The toolchain selection is controlled by the \code{TCMODE}
+      variable.
+    \item It defaults to \code{"default"}.
+    \item The \code{conf/distro/include/tcmode-${TCMODE}.inc} file is
+      included.
+    \begin{itemize}
+      \item This configures the toolchain to use by defining preferred
+        providers and versions for packages such as \code{gcc},
+        \code{binutils}, \code{*libc}\dots
+    \end{itemize}
+    \item The providers' recipes define how to compile or/and install
+      the toolchain.
+    \item Toolchains can be built by the build system or external.
+  \end{itemize}
+\end{frame}