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/arch/sandbox/include/asm/rtc.h

@@ -0,0 +1,28 @@
+/*
+ * Simulate an I2C real time clock
+ *
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __asm_rtc_h
+#define __asm_rtc_h
+
+/* Register numbers in the sandbox RTC */
+enum {
+	REG_SEC		= 5,
+	REG_MIN,
+	REG_HOUR,
+	REG_MDAY,
+	REG_MON,
+	REG_YEAR,
+	REG_WDAY,
+
+	REG_RESET	= 0x20,
+
+	REG_COUNT	= 0x80,
+};
+
+#endif