Modifying the kernel_utility tool to create our magic blob.

src/platform/vboot_reference/vboot_firmware/include/utility.h

 /* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* Helper functions/wrappers for memory allocations, manipulation and
  * comparison.
  */
 
 #ifndef VBOOT_REFERENCE_UTILITY_H_
@@ skipping 67 matching lines @@
 /* Like StatefulMemcpy() but copies in the opposite direction, populating
  * data from [src] into the buffer encapsulated in state [state].
  * On success, return [src] and update [state].
  * On failure, return NULL, set remaining_len in state to -1.
  *
  * Useful for iterating through a structure to populate a binary blob. After the
  * first failure (buffer overrun), successive calls will always fail.
  */
 const void* StatefulMemcpy_r(MemcpyState* state, const void* src, uint64_t len);
 
+/* Like StatefulMemcpy_r() but fills a portion of the encapsulated buffer with
+ * a constant value.
+ * On success, return a meaningless but non-NULL pointer and updates [state].
+ * On failure, return NULL, set remaining_len in state to -1.
+ *
+ * After the first failure (buffer overrun), successive calls will always fail.
+ */
+const void* StatefulMemset_r(MemcpyState* state, const uint8_t val,
+                             uint64_t len);
+
+
 #endif  /* VBOOT_REFERENCE_UTILITY_H_ */