UBI slides: add more U-Boot commands

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>

slides/sysdev-flash-filesystems/sysdev-flash-filesystems.tex

@@ -760,6 +760,23 @@ \section{Flash storage and filesystems}
     \end{itemize}
 \end{frame}
 
+\begin{frame}
+  \frametitle{U-Boot: UBI tools (3)}
+  U-Boot also has commands to access UBIFS partitions:
+    \begin{itemize}
+    \item \code{ubifsmount <volume-name>}\\
+	Mount the specified volume. Example:\\
+        \code{ubifsmount root}
+    \item \code{ubifsload <addr> <filename> [bytes]}\\
+	Load file contents at the specified address. Example:\\
+	\code{ubifsload 0x21000000 boot/zImage}
+    \item Other commands: \code{ubifsls} and \code{ubifsumount}
+    \end{itemize}
+    This shows that to optimize space, the kernel and DTB can
+    also be stored in a UBIFS partition. Otherwise, the DTB volume
+    consumes an entire LEB.
+\end{frame}
+
 \begin{frame}
   \frametitle{Linux: UBI target tools (1)}
   \begin{itemize}