diff --git a/configs/eagle100/README.txt b/configs/eagle100/README.txt
index f7af42c718..a4994f29ca 100644
--- a/configs/eagle100/README.txt
+++ b/configs/eagle100/README.txt
@@ -40,7 +40,7 @@ GNU Toolchain Options
 
   NOTE: the CodeSourcery and devkitARM toolchains are Windows native toolchains.
   The NuttX buildroot toolchain is a Cygwin toolchain.  There are several limitations
-  to using a Windows based toolchain in a Cygwin environment.  The two biggest are:
+  to using a Windows based toolchain in a Cygwin environment.  The three biggest are:
 
   1. The Windows toolchain cannot follow Cygwin paths.  Path conversions are
      performed automatically in the Cygwin makefiles using the 'cygpath' utility
@@ -59,6 +59,14 @@ GNU Toolchain Options
 
      An alias in your .bashrc file might make that less painful.
 
+  3. Dependencies are not made when using Windows versions of the GCC.  This is
+     because the dependencies are generated using Windows pathes which do not
+     work with the Cygwin make.
+
+  NOTE: The CodeSourcery toolchain (2009q1) does not work with default optimization
+  level of -Os (See Make.defs).  It will work with -O0, -O1, or -O2, but not with
+  -Os.
+
 NuttX buildroot Toolchain
 ^^^^^^^^^^^^^^^^^^^^^^^^^