[FE training-materials-updates] sysdev-kernel-cross-compiling: clarify explanation

[Thomas Petazzoni]

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

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=ecc26a339a457c441042e5638bfffe31c2883e04

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

commit ecc26a339a457c441042e5638bfffe31c2883e04
Author: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Date:   Mon Dec 2 10:42:53 2013 +0100

    sysdev-kernel-cross-compiling: clarify explanation
    
    Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>


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

ecc26a339a457c441042e5638bfffe31c2883e04
 .../sysdev-kernel-cross-compiling.tex              |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex b/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex
index 2e4112f..227805f 100644
--- a/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex
+++ b/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex
@@ -70,10 +70,13 @@ In the kernel configuration :
 
 \item Disable support for the IGEPv2 board compiled into the kernel
   (\code{CONFIG_MACH_IGEP0020}). We will boot our kernel with a device
-  tree for our board, and won't compile the board description
-  file (\code{arch/arm/mach-omap2/board-igep0020.c} in the kernel
-  sources.). You will have to review dependencies to be able to disable
-  this kernel configuration setting. 
+  tree for our board, and won't compile the board description file
+  (\code{arch/arm/mach-omap2/board-igep0020.c} in the kernel
+  sources.). Technically speaking, you can leave this option enabled,
+  and still boot using a {\em Device Tree}, but disabling it makes
+  sure that your board will not fall back to legacy booting if you do
+  a mistake! You will have to review dependencies to be able to
+  disable this kernel configuration setting.
 \item As an experiment, let's change the kernel compression from Gzip
   to XZ. This compression algorithm is far more efficient than Gzip,
   in terms of compression ratio, at the expense of a higher