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/tools/rksd.c

@@ -0,0 +1,87 @@
+/*
+ * (C) Copyright 2015 Google,  Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ *
+ * See README.rockchip for details of the rksd format
+ */
+
+#include "imagetool.h"
+#include <image.h>
+#include <rc4.h>
+#include "mkimage.h"
+#include "rkcommon.h"
+
+static char dummy_hdr[RK_IMAGE_HEADER_LEN];
+
+static int rksd_verify_header(unsigned char *buf,  int size,
+				 struct image_tool_params *params)
+{
+	return 0;
+}
+
+static void rksd_print_header(const void *buf)
+{
+}
+
+static void rksd_set_header(void *buf,  struct stat *sbuf,  int ifd,
+			       struct image_tool_params *params)
+{
+	unsigned int size;
+	int ret;
+
+	size = params->file_size - RK_SPL_HDR_START;
+	ret = rkcommon_set_header(buf, size, params);
+	if (ret) {
+		/* TODO(sjg@chromium.org): This method should return an error */
+		printf("Warning: SPL image is too large (size %#x) and will not boot\n",
+		       size);
+	}
+
+	memcpy(buf + RK_SPL_HDR_START, rkcommon_get_spl_hdr(params),
+	       RK_SPL_HDR_SIZE);
+}
+
+static int rksd_extract_subimage(void *buf,  struct image_tool_params *params)
+{
+	return 0;
+}
+
+static int rksd_check_image_type(uint8_t type)
+{
+	if (type == IH_TYPE_RKSD)
+		return EXIT_SUCCESS;
+	else
+		return EXIT_FAILURE;
+}
+
+/* We pad the file out to a fixed size - this method returns that size */
+static int rksd_vrec_header(struct image_tool_params *params,
+			    struct image_type_params *tparams)
+{
+	int pad_size;
+
+	pad_size = RK_SPL_HDR_START + rkcommon_get_spl_size(params);
+	debug("pad_size %x\n", pad_size);
+
+	return pad_size - params->file_size;
+}
+
+/*
+ * rk_sd parameters
+ */
+U_BOOT_IMAGE_TYPE(
+	rksd,
+	"Rockchip SD Boot Image support",
+	RK_IMAGE_HEADER_LEN,
+	dummy_hdr,
+	rkcommon_check_params,
+	rksd_verify_header,
+	rksd_print_header,
+	rksd_set_header,
+	rksd_extract_subimage,
+	rksd_check_image_type,
+	NULL,
+	rksd_vrec_header
+);