diff --git a/util/cbfstool/cbfs_image.c b/util/cbfstool/cbfs_image.c
new file mode 100644
index 0000000..5754453
--- /dev/null
+++ b/util/cbfstool/cbfs_image.c
@@ -0,0 +1,128 @@
+/*
+ * CBFS Image Manipulation
+ *
+ * Copyright (C) 2013 The Chromium OS Authors. All rights reserved.
+ *
+ * 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
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "common.h"
+#include "cbfs_image.h"
+
+/* The file name align is not defined in CBFS spec -- only a preference by
+ * (old) cbfstool. */
+#define CBFS_FILENAME_ALIGN	(16)
+
+/* To make CBFS more friendly to ROM, fill -1 (0xFF) instead of zero. */
+#define CBFS_CONTENT_DEFAULT_VALUE	(-1)
+
+static uint32_t align_up(uint32_t value, uint32_t align) {
+	if (value % align)
+		value += align - (value % align);
+	return value;
+}
+
+int cbfs_image_from_file(struct cbfs_image *image, const char *filename) {
+	if (buffer_from_file(&image->buffer, filename) != 0)
+		return -1;
+	DEBUG("read_cbfs_image: %s (%zd bytes)\n", image->buffer.name,
+	      image->buffer.size);
+	image->header = cbfs_find_header(image->buffer.data,
+					 image->buffer.size);
+	if (!image->header) {
+		ERROR("%s does not have CBFS master header.\n", filename);
+		cbfs_image_delete(image);
+		return -1;
+	}
+
+	return 0;
+}
+
+int cbfs_image_write_file(struct cbfs_image *image, const char *filename) {
+	assert(image && image->buffer.data);
+	return buffer_write_file(&image->buffer, filename);
+}
+
+int cbfs_image_delete(struct cbfs_image *image) {
+	buffer_delete(&image->buffer);
+	image->header = NULL;
+	return 0;
+}
+
+struct cbfs_header *cbfs_find_header(char *data, size_t size) {
+	size_t offset;
+	int found = 0;
+	uint32_t x86sig;
+	struct cbfs_header *header, *result = NULL;
+
+	// Try x86 style (check signature in bottom) header first.
+	x86sig = *(uint32_t *)(data + size - sizeof(uint32_t));
+	offset = (x86sig + (uint32_t)size);
+	DEBUG("x86sig: 0x%x, offset: 0x%zx\n", x86sig, offset);
+	if (offset >= size - sizeof(*header) ||
+	    ntohl(((struct cbfs_header *)(data + offset))->magic) !=
+	    CBFS_HEADER_MAGIC)
+		offset = 0;
+
+	for (; offset + sizeof(*header) < size; offset++) {
+		header = (struct cbfs_header *)(data + offset);
+		if (ntohl(header->magic) !=(CBFS_HEADER_MAGIC))
+		    continue;
+		if (ntohl(header->version) != CBFS_HEADER_VERSION1 &&
+		    ntohl(header->version) != CBFS_HEADER_VERSION2) {
+			// Probably not a real CBFS header?
+			continue;
+		}
+		found++;
+		result = header;
+	}
+	if (found > 1) {
+		ERROR("multiple (%d) CBFS headers found!\n",
+		       found);
+		result = NULL;
+	}
+	return result;
+}
+
+
+struct cbfs_file *cbfs_find_first_entry(struct cbfs_image *image) {
+	assert(image && image->header);
+	return (struct cbfs_file *)(image->buffer.data +
+				   ntohl(image->header->offset));
+}
+
+struct cbfs_file *cbfs_find_next_entry(struct cbfs_image *image,
+				       struct cbfs_file *entry) {
+	uint32_t addr = cbfs_get_entry_addr(image, entry);
+	int align = ntohl(image->header->align);
+	assert(entry && cbfs_is_valid_entry(entry));
+	addr += ntohl(entry->offset) + ntohl(entry->len);
+	addr = align_up(addr, align);
+	return (struct cbfs_file *)(image->buffer.data + addr);
+}
+
+uint32_t cbfs_get_entry_addr(struct cbfs_image *image, struct cbfs_file *entry) {
+	assert(image && image->buffer.data && entry);
+	return (int32_t)((char *)entry - image->buffer.data);
+}
+
+int cbfs_is_valid_entry(struct cbfs_file *entry) {
+	return (entry &&memcmp(entry->magic, CBFS_FILE_MAGIC,
+			       sizeof(entry->magic)) == 0);
+}
+