1 files changed, 34 insertions, 0 deletions
diff --git a/src/commonlib/bsd/include/commonlib/bsd/metadata_hash.h b/src/commonlib/bsd/include/commonlib/bsd/metadata_hash.h
new file mode 100644
index 0000000000..d5e54b508e
--- /dev/null
+++ b/src/commonlib/bsd/include/commonlib/bsd/metadata_hash.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0-only */
+
+#ifndef _COMMONLIB_BSD_METADATA_HASH_H_
+#define _COMMONLIB_BSD_METADATA_HASH_H_
+
+#include <stdint.h>
+#include <vb2_sha.h>
+
+/* This structure is embedded somewhere in the (uncompressed) bootblock. */
+struct metadata_hash_anchor {
+	uint8_t magic[8];
+	struct vb2_hash cbfs_hash;
+	/* NOTE: This is just reserving space. sizeof(struct vb2_hash) may change between
+	   configurations/versions and cannot be relied upon, so the FMAP hash must be placed
+	   right after the actual data for the particular CBFS hash algorithm used ends. */
+	uint8_t reserved_space_for_fmap_hash[VB2_MAX_DIGEST_SIZE];
+} __packed;
+
+/* Always use this function to figure out the actual location of the FMAP hash. It always uses
+   the same algorithm as the CBFS hash. */
+static inline uint8_t *metadata_hash_anchor_fmap_hash(struct metadata_hash_anchor *anchor)
+{
+	return anchor->cbfs_hash.raw + vb2_digest_size(anchor->cbfs_hash.algo);
+}
+
+/*
+ * Do not use this constant anywhere else in coreboot code to ensure the bit pattern really only
+ * appears once in the CBFS image. The only coreboot file allowed to use this is
+ * src/lib/metadata_anchor.c to define the actual anchor data structure. It is defined here so
+ * that it can be shared with cbfstool (which may use it freely).
+ */
+#define DO_NOT_USE_METADATA_HASH_ANCHOR_MAGIC_DO_NOT_USE	"\xadMdtHsh\x15"
+
+#endif /* _COMMONLIB_BSD_MASTER_HASH_H_ */