1 files changed, 4 insertions, 0 deletions
diff --git a/README.md b/README.md
index 0dade3c..740c872 100644
--- a/README.md
+++ b/README.md
@@ -47,6 +47,7 @@ DOMU_VCPUS[1]=1
 
 UBOOT_SOURCE="boot.source"
 UBOOT_SCRIPT="boot.scr"
+FDTEDIT="imagebuilder.dtb"
 ```
 
 Where:
@@ -94,6 +95,9 @@ Where:
   as you can pass -o FILENAME to uboot-script-gen as a command line
   parameter
 
+- FDTEDIT is an optional and is off by default.  Specifies the output
+  modifited dtb, used for reference only.
+
 Then you can invoke uboot-script-gen as follows:
 
 ```