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/system.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __ASM_SANDBOX_SYSTEM_H
+#define __ASM_SANDBOX_SYSTEM_H
+
+/* Define this as nops for sandbox architecture */
+#define local_irq_save(x)
+#define local_irq_enable()
+#define local_irq_disable()
+#define local_save_flags(x)
+#define local_irq_restore(x)
+
+#endif