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/mips/mach-ath79/dram.c

@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/sizes.h>
+#include <asm/addrspace.h>
+#include <mach/ddr.h>
+
+phys_size_t initdram(int board_type)
+{
+	ddr_tap_tuning();
+	return get_ram_size((void *)KSEG1, SZ_256M);
+}