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/mach-tegra/tegra210/funcmux.c

@@ -0,0 +1,40 @@
+/*
+ * (C) Copyright 2013-2015
+ * NVIDIA Corporation <www.nvidia.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+/* Tegra210 high-level function multiplexing */
+
+#include <common.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/funcmux.h>
+#include <asm/arch/pinmux.h>
+
+int funcmux_select(enum periph_id id, int config)
+{
+	int bad_config = config != FUNCMUX_DEFAULT;
+
+	switch (id) {
+	/*
+	 * Add other periph IDs here as needed.
+	 * Note that all pinmux/pads should have already
+	 * been set up in the board pinmux table in
+	 * pinmux-config-<board>.h for all periphs.
+	 * Leave this in for the odd case where a mux
+	 * needs to be changed on-the-fly.
+	 */
+
+	default:
+		debug("%s: invalid periph_id %d", __func__, id);
+		return -1;
+	}
+
+	if (bad_config) {
+		debug("%s: invalid config %d for periph_id %d", __func__,
+		      config, id);
+		return -1;
+	}
+	return 0;
+}