security/vboot: Add store/validate methods for AMD VBIOS FMAP cache

Add methods to store and retrieve the hash of the data stored in the
VBIOS cache FMAP region. Add a dedicated index in TPM NVRAM to store
the hash, and methods to calculate/read/write it.

Modeled after mrc_cache_hash_tpm.{c,h}

BUG=b:255812886
TEST=tested with rest of patch train

Change-Id: I030017d3bf956b8593bc09073ad6545b80a5b52b
Signed-off-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/72401
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/security/vboot/vbios_cache_hash_tpm.h b/src/security/vboot/vbios_cache_hash_tpm.h
new file mode 100644
index 0000000000..166fcaaeac
--- /dev/null
+++ b/src/security/vboot/vbios_cache_hash_tpm.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _VBIOS_CACHE_HASH_TPM_H_
+#define _VBIOS_CACHE_HASH_TPM_H_
+
+#include <types.h>
+
+/*
+ * Updates vbios cache hash.
+ */
+void vbios_cache_update_hash(const uint8_t *data, size_t size);
+
+/*
+ * Verifies vbios cache hash which is stored in FMAP region.
+ */
+enum cb_err vbios_cache_verify_hash(const uint8_t *data, size_t size);
+
+#endif /* _VBIOS_CACHE_HASH_TPM_H_ */