rockchip: Add the rkimage format to mkimage

Rockchip SoCs require certain formats for code that they execute, The
simplest format is a 4-byte header at the start of a binary file. Add
support for this so that we can create images that the boot ROM understands.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/rkcommon.h

@@ -0,0 +1,28 @@
+/*
+ * (C) Copyright 2015 Google,  Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _RKCOMMON_H
+#define _RKCOMMON_H
+
+enum {
+	RK_BLK_SIZE		= 512,
+	RK_CODE1_OFFSET		= 4,
+	RK_MAX_CODE1_SIZE	= 32 << 10,
+};
+
+/**
+ * rkcommon_set_header() - set up the header for a Rockchip boot image
+ *
+ * This sets up a 2KB header which can be interpreted by the Rockchip boot ROM.
+ *
+ * @buf:	Pointer to header place (must be at least 2KB in size)
+ * @file_size:	Size of the file we want the boot ROM to load, in bytes
+ * @return 0 if OK, -ENOSPC if too large
+ */
+int rkcommon_set_header(void *buf, uint file_size);
+
+#endif