Automatic software update from TFTP server

The auto-update feature allows to automatically download software updates
from a TFTP server and store them in Flash memory during boot. Updates are
contained in a FIT file and protected with SHA-1 checksum.

More detailed description can be found in doc/README.update.

Signed-off-by: Rafal Czubak <rcz@semihalf.com>
Signed-off-by: Bartlomiej Sieka <tur@semihalf.com>
diff --git a/doc/uImage.FIT/update_uboot.its b/doc/uImage.FIT/update_uboot.its
new file mode 100644
index 0000000..e0d27ea
--- /dev/null
+++ b/doc/uImage.FIT/update_uboot.its
@@ -0,0 +1,21 @@
+/*
+ * Automatic software update for U-Boot
+ * Make sure the flashing addresses ('load' prop) is correct for your board!
+ */
+/ {
+	description = "Automatic U-Boot update";
+	#address-cells = <1>;
+
+	images {
+		update@1 {
+			description = "U-Boot binary";
+			data = /incbin/("./u-boot.bin");
+			compression = "none";
+			type = "firmware";
+			load = <FFFC0000>;
+			hash@1 {
+				algo = "sha1";
+			};
+		};
+	};
+};