Explain why we don't support ELDK toolchains.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

docs/buildroot.html

@@ -740,6 +740,31 @@ $(ZLIB_DIR)/libz.a: $(ZLIB_DIR)/.configured
     toolchains that support the <i>sysroot</i> feature should
     work. If not, do not hesitate to contact the developers.</p>
 
+    <p>We do not support toolchains from
+    the <a href="http://www.denx.de/wiki/DULG/ELDK">ELDK of Denx</a>,
+    for two reasons:</p>
+
+    <ul>
+
+      <li>The ELDK does not contain a pure toolchain (i.e just the
+      compiler, binutils, the C and C++ libraries), but a toolchain
+      that comes with a very large set of pre-compiled libraries and
+      programs. Therefore, Buildroot cannot import the <i>sysroot</i>
+      of the toolchain, as it would contain hundreds of megabytes of
+      pre-compiled libraries that are normally built by
+      Buildroot.</li>
+
+      <li>The ELDK toolchains have a completely non-standard custom
+      mechanism to handle multiple library variants. Instead of using
+      the standard GCC <i>multilib</i> mechanism, the ARM ELDK uses
+      different symbolic links to the compiler to differentiate
+      between library variants (for ARM soft-float and ARM VFP), and
+      the PowerPC ELDK compiler uses a <code>CROSS_COMPILE</code>
+      environment variable. This non-standard behaviour makes it
+      difficult to support ELDK in Buildroot.</li>
+
+    </ul>
+
     <h2 id="add_packages">Adding new packages to Buildroot</h2>
 
     <p>This section covers how new packages (userspace libraries or