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/libfdt/fdt_strerror.c

@@ -0,0 +1,55 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2006 David Gibson, IBM Corporation.
+ * SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause
+ */
+#include <libfdt_env.h>
+
+#ifndef USE_HOSTCC
+#include <fdt.h>
+#include <libfdt.h>
+#else
+#include "fdt_host.h"
+#endif
+
+#include "libfdt_internal.h"
+
+struct fdt_errtabent {
+	const char *str;
+};
+
+#define FDT_ERRTABENT(val) \
+	[(val)] = { .str = #val, }
+
+static struct fdt_errtabent fdt_errtable[] = {
+	FDT_ERRTABENT(FDT_ERR_NOTFOUND),
+	FDT_ERRTABENT(FDT_ERR_EXISTS),
+	FDT_ERRTABENT(FDT_ERR_NOSPACE),
+
+	FDT_ERRTABENT(FDT_ERR_BADOFFSET),
+	FDT_ERRTABENT(FDT_ERR_BADPATH),
+	FDT_ERRTABENT(FDT_ERR_BADSTATE),
+
+	FDT_ERRTABENT(FDT_ERR_TRUNCATED),
+	FDT_ERRTABENT(FDT_ERR_BADMAGIC),
+	FDT_ERRTABENT(FDT_ERR_BADVERSION),
+	FDT_ERRTABENT(FDT_ERR_BADSTRUCTURE),
+	FDT_ERRTABENT(FDT_ERR_BADLAYOUT),
+};
+#define FDT_ERRTABSIZE	(sizeof(fdt_errtable) / sizeof(fdt_errtable[0]))
+
+const char *fdt_strerror(int errval)
+{
+	if (errval > 0)
+		return "<valid offset/length>";
+	else if (errval == 0)
+		return "<no error>";
+	else if (errval > -FDT_ERRTABSIZE) {
+		const char *s = fdt_errtable[-errval].str;
+
+		if (s)
+			return s;
+	}
+
+	return "<unknown error>";
+}