[FE training-materials-updates] Elaborate on how to set ARCH and CROSS_COMPILE

[Michael Opdenacker]

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

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=aedbe78eeeeaae1936ce279444859605df3f230e

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

commit aedbe78eeeeaae1936ce279444859605df3f230e
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date:   Wed Oct 3 06:44:57 2012 +0200

    Elaborate on how to set ARCH and CROSS_COMPILE


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

aedbe78eeeeaae1936ce279444859605df3f230e
 .../sysdev-linux-intro-cross-compilation.tex       |   41 ++++++++++++++------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/slides/sysdev-linux-intro-cross-compilation/sysdev-linux-intro-cross-compilation.tex b/slides/sysdev-linux-intro-cross-compilation/sysdev-linux-intro-cross-compilation.tex
index 2a4d94a..a643a2b 100644
--- a/slides/sysdev-linux-intro-cross-compilation/sysdev-linux-intro-cross-compilation.tex
+++ b/slides/sysdev-linux-intro-cross-compilation/sysdev-linux-intro-cross-compilation.tex
@@ -18,8 +18,8 @@
   \end{itemize}
 \end{frame}
 
-\begin{frame}[fragile]
-  \frametitle{Specifying cross-compilation}
+\begin{frame}
+  \frametitle{Specifying cross-compilation (1)}
 
   The CPU architecture and cross-compiler prefix are defined through
   the \code{ARCH} and \code{CROSS_COMPILE} variables in the toplevel
@@ -28,21 +28,38 @@
   \begin{itemize}
   \item \code{ARCH} is the name of the architecture. It is defined by
     the name of the subdirectory in \code{arch/} in the kernel sources
+    \begin{itemize}
+    \item Example: \code{arm} if you want to compile a kernel for
+          the \code{arm} architecture.
+    \end{itemize}
   \item \code{CROSS_COMPILE} is the prefix of the cross compilation
     tools
     \begin{itemize}
     \item Example: \code{arm-linux-} if your compiler is \code{arm-linux-gcc}
     \end{itemize}
-  \item Two solutions
-    \begin{itemize}
-    \item Pass \code{ARCH} and \code{CROSS_COMPILE} on the \code{make}
-      command line
-    \item Define \code{ARCH} and \code{CROSS_COMPILE} as environment
-      variables
-    \item Don't forget to have the values properly set at all steps,
-      otherwise the kernel configuration and build system gets
-      confused
-    \end{itemize}
+  \end{itemize}
+\end{frame}
+
+\begin{frame}
+  \frametitle{Specifying cross-compilation (2)}
+
+  Two solutions to define \code{ARCH} and \code{CROSS_COMPILE}:
+
+  \begin{itemize}
+  \item Pass \code{ARCH} and \code{CROSS_COMPILE} on the \code{make}
+    command line: \\
+    \code{make ARCH=arm CROSS_COMPILE=arm-linux- ...} \\
+    Not recommended, because you can screw up your build and
+    configuration if you ever forget to pass these variables when
+    you run any \code{make} command.
+  \item Define \code{ARCH} and \code{CROSS_COMPILE} as environment
+    variables: \\
+    \code{export ARCH=arm} \\
+    \code{export CROSS_COMPILE=arm-linux-} \\
+    Recommended solution, but it only works inside the current
+    shell or terminal. You may put these settings in your
+    \code{~/.bashrc} file to make them permanent and visible from
+    anywhere.
   \end{itemize}
 \end{frame}