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/arm/cpu/arm720t/cpu.c

@@ -0,0 +1,22 @@
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * cleanup_before_linux() - Prepare the CPU to jump to Linux
+ *
+ * This function is called just before we call Linux, it
+ * prepares the processor for linux
+ */
+int cleanup_before_linux(void)
+{
+	return 0;
+}