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/sections.h

@@ -0,0 +1,24 @@
+/*
+ * decls for symbols defined in the linker script
+ *
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __SANDBOX_SECTIONS_H
+#define __SANDBOX_SECTIONS_H
+
+#include <asm-generic/sections.h>
+
+struct sandbox_cmdline_option;
+
+extern struct sandbox_cmdline_option *__u_boot_sandbox_option_start[],
+	*__u_boot_sandbox_option_end[];
+
+static inline size_t __u_boot_sandbox_option_count(void)
+{
+	return __u_boot_sandbox_option_end - __u_boot_sandbox_option_start;
+}
+
+#endif