fdt: Make it easier to debug u-boot.dtsi files
At present one must hack the Makefile to see what is going on with these
files. Also it doesn't quite work correctly.
Fix this by using an environment variable for debugging. Update the docs
also.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 39f0339..b4e63bc 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -175,7 +175,9 @@
# Uncomment for debugging
# This shows all the files that were considered and the one that we chose.
-# u_boot_dtsi_options_debug = $(u_boot_dtsi_options_raw)
+ifdef DEVICE_TREE_DEBUG
+u_boot_dtsi_options_debug = $(warning $(u_boot_dtsi_options_raw))
+endif
# We use the first match
u_boot_dtsi = $(strip $(u_boot_dtsi_options_debug) \