diff --git a/util/cbfstool/fmd.h b/util/cbfstool/fmd.h
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+++ b/util/cbfstool/fmd.h
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+/*
+ * fmd.h, parser frontend and utility functions for flashmap descriptor language
+ *
+ * Copyright (C) 2015 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
+ */
+
+#ifndef FMD_H_
+#define FMD_H_
+
+#include <limits.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#define FMD_NOTFOUND UINT_MAX
+
+struct flashmap_descriptor {
+	char *name;
+	bool offset_known;
+	/**
+	 * Offset relative to that of the parent node.
+	 * Exception: for the root node in the descriptor tree, it is optional.
+	 * In this case, if absent, it indicates that the flash chip will not be
+	 * memory mapped at runtime; otherwise, its value indicates the base
+	 * address of the flash chip in the virtual address space rather than
+	 * representing an offset into the flash image itself.
+	 * It is an error to read this field unless offset_known is set.
+	 */
+	unsigned offset;
+	bool size_known;
+	/** It is an error to read this field unless size_known is set. */
+	unsigned size;
+	size_t list_len;
+	/** It is an error to dereference this array if list_len is 0. */
+	struct flashmap_descriptor **list;
+};
+
+/**
+ * **Client-defined** callback.
+ * This call is used to notify client code that the user has annotated the given
+ * section node by accompanying it with a string enclosed in parentheses. It is
+ * only invoked for nodes that have annotations, and then only once per node.
+ * The annotations' syntactic validity and semantic meaning are not determined
+ * by the compiler; rather, implementations of this function should use their
+ * return type to tell the compiler whether the annotation was valid syntax, as
+ * well as perform whatever actions are necessary given the particular
+ * annotation. It's worth reiterating that this is only called on section nodes,
+ * and will never be called with the final, complete flashmap_descriptor because
+ * it is impossible to annotate the image as a whole. Note that, although the
+ * node received by this function will be preserved in memory as part of the
+ * ultimate flashmap_descriptor, the annotation string will only persist during
+ * this function call: if the implementation needs it longer, it must copy it.
+ *
+ * @param flashmap_descriptor The section node carrying the annotation
+ * @param annotation          What the user wrote (only valid during callback)
+ * @return                    Whether this annotation represented valid syntax
+ */
+bool fmd_process_annotation_impl(const struct flashmap_descriptor *node,
+							const char *annotation);
+
+/**
+ * Parse and validate a flashmap descriptor from the specified stream.
+ * As part of this process, any fields that were omitted in the input are
+ * inferred from whatever information is known, if possible. The result is a
+ * tree with all its offset and size fields filled, except possibly the former
+ * part of the root node in the case of non--memory mapped flash. If a syntax
+ * error causes the parser to fail, or if there is not enough information given
+ * in the input file to determine any single missing value, the specific error
+ * is reported to standard error and this function returns NULL.
+ *
+ * @param stream File from which to read the (partial) flashmap descriptor
+ * @return       Populated flashmap descriptor tree, or NULL on failure
+ */
+struct flashmap_descriptor *fmd_create(FILE *stream);
+
+/** @param victim Valid descriptor tree to be cleaned up, or NULL for no-op */
+void fmd_cleanup(struct flashmap_descriptor *victim);
+
+/**
+ * @param tree Must be non-NULL
+ * @return     The number of nodes in the tree, including the root
+ */
+size_t fmd_count_nodes(const struct flashmap_descriptor *tree);
+
+/**
+ * @param root The flashmap descriptor to search
+ * @param name The name of the sought-after section
+ * @return     The desired section node, or NULL if none was found
+ */
+const struct flashmap_descriptor *fmd_find_node(
+		const struct flashmap_descriptor *root, const char *name);
+
+/**
+ * @param root Parent node to whose start the "absolute" offset will be relative
+ * @param name The name of the node whose offset to determine
+ * @return     The "absolute" offset, or FMD_NOTFOUND if the node wasn't found
+ */
+unsigned fmd_calc_absolute_offset(const struct flashmap_descriptor *root,
+							const char *name);
+
+/** @param tree Must be non-NULL */
+void fmd_print(const struct flashmap_descriptor *tree);
+
+typedef struct flashmap_descriptor **flashmap_descriptor_iterator_t;
+
+/*
+ * Run the subsequent statement once on each descendant of the specified node.
+ *
+ * @param iterator A flashmap_descriptor_iterator_t (automatically declared)
+ * @param parent   The parent node of those over which the loop should iterate
+ */
+#define fmd_foreach_child_iterator(iterator, parent) \
+	for (flashmap_descriptor_iterator_t iterator = parent->list; \
+		iterator < parent->list + parent->list_len; ++iterator)
+
+/*
+ * Run the subsequent statement once on each descendant of the specified node.
+ *
+ * @param child  A struct flashmap_descriptor * (automatically declared)
+ * @param parent The parent node of those over which the loop should iterate
+ */
+#define fmd_foreach_child(child, parent) \
+	for (struct flashmap_descriptor **fmd_foreach_child_iterator_ = \
+						parent->list, *child = NULL; \
+						fmd_foreach_child_iterator_ < \
+					parent->list + parent->list_len && \
+				(child = *fmd_foreach_child_iterator_); \
+						++fmd_foreach_child_iterator_)
+
+#endif