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/lib/crc8.c

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include "linux/crc8.h"
+
+#define POLY	(0x1070U << 3)
+
+static unsigned char _crc8(unsigned short data)
+{
+	int i;
+
+	for (i = 0; i < 8; i++) {
+		if (data & 0x8000)
+			data = data ^ POLY;
+		data = data << 1;
+	}
+
+	return (unsigned char)(data >> 8);
+}
+
+unsigned int crc8(unsigned int crc, const unsigned char *vptr, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		crc = _crc8((crc ^ vptr[i]) << 8);
+
+	return crc;
+}