ARM: kirkwood: Enforce size limit for guruplug

The u-boot binary sits in flash immediately before the environment.
Don't allow the binary size to grow into the environment space.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>

include/configs/guruplug.h

@@ -39,6 +39,11 @@
  */
 #define CONFIG_ENV_SIZE			0x20000	/* 128k */
 #define CONFIG_ENV_OFFSET		0xE0000	/* env starts here */
+/*
+ * Environment is right behind U-Boot in flash. Make sure U-Boot
+ * doesn't grow into the environment area.
+ */
+#define CONFIG_BOARD_SIZE_LIMIT		CONFIG_ENV_OFFSET
 
 /*
  * Default environment variables