VBoot Reference: Add version checking to for preventing rollbacks.

src/platform/vboot_reference/include/rollback_index.h

+/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Functions for querying, manipulating and locking rollback indices
+ * stored in the TPM NVRAM.
+ */
+
+#ifndef VBOOT_REFERENCE_ROLLBACK_INDEX_H_
+#define VBOOT_REFERENCE_ROLLBACK_INDEX_H_
+
+#include <stdint.h>
+
+extern uint16_t g_firmware_key_version;
+extern uint16_t g_firmware_version;
+extern uint16_t g_kernel_key_version;
+extern uint16_t g_kernel_version;
+
+/* Rollback version types. */
+#define FIRMWARE_KEY_VERSION 0
+#define FIRMWARE_VERSION 1
+#define KERNEL_KEY_VERSION 2
+#define KERNEL_VERSION 3
+
+/* TPM NVRAM location indices. */
+#define FIRMWARE_KEY_VERSION_NV_INDEX  0x1001
+#define FIRMWARE_VERSION_NV_INDEX 0x1002
+#define KERNEL_KEY_VERSION_NV_INDEX 0x1003
+#define KERNEL_VERSION_NV_INDEX 0x1004
+
+void SetupTPM(void);
+uint16_t GetStoredVersion(int type);
+int WriteStoredVersion(int type, uint16_t version);
+void LockStoredVersion(int type);
+
+#endif  /* VBOOT_REFERENCE_ROLLBACK_INDEX_H_ */