avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/include/cros_ec_message.h

@@ -0,0 +1,29 @@
+/*
+ * Chromium OS Matrix Keyboard Message Protocol definitions
+ *
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _CROS_MESSAGE_H
+#define _CROS_MESSAGE_H
+
+/*
+ * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
+ *
+ * This is copied from the Chromium OS Open Source Embedded Controller code.
+ */
+enum {
+	/* The header byte, which follows the preamble */
+	MSG_HEADER	= 0xec,
+
+	MSG_HEADER_BYTES	= 3,
+	MSG_TRAILER_BYTES	= 2,
+	MSG_PROTO_BYTES		= MSG_HEADER_BYTES + MSG_TRAILER_BYTES,
+
+	/* Max length of messages */
+	MSG_BYTES		= EC_PROTO2_MAX_PARAM_SIZE + MSG_PROTO_BYTES,
+};
+
+#endif