README.falcon: Document environment variables for falcon mode

Signed-off-by: Tom Rini <trini@ti.com>

diff --git a/doc/README.falcon b/doc/README.falcon
index 6357b1e593377112deba187f6a0936498bb19f7d..bccf6c95c869388ae6824a50ccb25e378d925104 100644 (file)
--- a/doc/README.falcon
+++ b/doc/README.falcon
@@ -80,6 +80,15 @@ spl_start_uboot() : required
                Returns "0" if SPL should start the kernel, "1" if U-Boot
                must be started.
 
+Environment variables
+---------------------
+
+A board may chose to look at the environment for decisions about falcon
+mode.  In this case the following variables may be supported:
+
+boot_os :              Set to yes/Yes/true/True/1 to enable booting to OS,
+                       any other value to fall back to U-Boot (including
+                       unset)
 
 Using spl command
 -----------------