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/board/samsung/smdk5420/smdk5420_spl.c

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2013 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/spl.h>
+#include <asm/arch/clk.h>
+
+#define SIGNATURE	0xdeadbeef
+
+/* Parameters of early board initialization in SPL */
+static struct spl_machine_param machine_param
+		__attribute__((section(".machine_param"))) = {
+	.signature	= SIGNATURE,
+	.version	= 1,
+	.params		= "vmubfasirM",
+	.size		= sizeof(machine_param),
+
+	.mem_iv_size	= 0x1f,
+	.mem_type	= DDR_MODE_DDR3,
+
+	/*
+	 * Set uboot_size to 0x100000 bytes.
+	 *
+	 * This is an overly conservative value chosen to accommodate all
+	 * possible U-Boot image.  You are advised to set this value to a
+	 * smaller realistic size via scripts that modifies the .machine_param
+	 * section of output U-Boot image.
+	 */
+	.uboot_size	= 0x100000,
+
+	.boot_source	= BOOT_MODE_OM,
+	.frequency_mhz	= 800,
+	.arm_freq_mhz	= 900,
+	.serial_base	= 0x12c30000,
+	.i2c_base	= 0x12c60000,
+	.mem_manuf	= MEM_MANUF_SAMSUNG,
+};
+
+struct spl_machine_param *spl_get_machine_params(void)
+{
+	if (machine_param.signature != SIGNATURE) {
+		/* Will hang if SIGNATURE dont match */
+		while (1)
+			;
+	}
+
+	return &machine_param;
+}