util: add smmstoretool for editing SMMSTORE

Offline SMMSTORE variable modification tool.  Can be used to
pre-configure ROM image or debug EFI state stored in a dump.

Change-Id: I6c1c06f1d0c39c13b5be76a3070f09b715aca6e0
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79080
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

util/smmstoretool/fv.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef SMMSTORETOOL__FV_H__
+#define SMMSTORETOOL__FV_H__
+
+#include <stdbool.h>
+
+#include "utils.h"
+
+// Firmware volume is what's stored in SMMSTORE region of CBFS.  It wraps
+// variable store.
+
+bool fv_init(struct mem_range_t fv);
+
+bool fv_parse(struct mem_range_t fv,
+	      struct mem_range_t *var_store,
+	      bool *auth_vars);
+
+#endif // SMMSTORETOOL__FV_H__