diff --git a/include/tcg.h b/include/tcg.h
new file mode 100644
index 0000000..c9bb341
--- /dev/null
+++ b/include/tcg.h
@@ -0,0 +1,304 @@
+/*
+ * Copyright (c) 2020-2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef TCG_H
+#define TCG_H
+
+#include <sha_common_macros.h>
+#include <stdint.h>
+
+#define TCG_ID_EVENT_SIGNATURE_03 "Spec ID Event03"
+#define TCG_STARTUP_LOCALITY_SIGNATURE "StartupLocality"
+
+#define TCG_SPEC_VERSION_MAJOR_TPM2 2
+#define TCG_SPEC_VERSION_MINOR_TPM2 0
+#define TCG_SPEC_ERRATA_TPM2 2
+
+/*
+ * Event types
+ * Ref. Table 9 Events
+ * TCG PC Client Platform Firmware Profile Specification.
+ */
+#define EV_PREBOOT_CERT 0x00000000U
+#define EV_POST_CODE 0x00000001U
+#define EV_UNUSED 0x00000002U
+#define EV_NO_ACTION 0x00000003U
+#define EV_SEPARATOR 0x00000004U
+#define EV_ACTION 0x00000005U
+#define EV_EVENT_TAG 0x00000006U
+#define EV_S_CRTM_CONTENTS 0x00000007U
+#define EV_S_CRTM_VERSION 0x00000008U
+#define EV_CPU_MICROCODE 0x00000009U
+#define EV_PLATFORM_CONFIG_FLAGS 0x0000000AU
+#define EV_TABLE_OF_DEVICES 0x0000000BU
+#define EV_COMPACT_HASH 0x0000000CU
+#define EV_IPL 0x0000000DU
+#define EV_IPL_PARTITION_DATA 0x0000000EU
+#define EV_NONHOST_CODE 0x0000000FU
+#define EV_NONHOST_CONFIG 0x00000010U
+#define EV_NONHOST_INFO 0x00000011U
+#define EV_OMIT_BOOT_DEVICE_EVENTS 0x00000012U
+#define EV_EFI_EVENT_BASE 0x80000000U
+#define EV_EFI_VARIABLE_DRIVER_CONFIG 0x80000001U
+#define EV_EFI_VARIABLE_BOOT 0x80000002U
+#define EV_EFI_BOOT_SERVICES_APPLICATION 0x80000003U
+#define EV_EFI_BOOT_SERVICES_DRIVER 0x80000004U
+#define EV_EFI_RUNTIME_SERVICES_DRIVER 0x80000005U
+#define EV_EFI_GPT_EVENT 0x80000006U
+#define EV_EFI_ACTION 0x80000007U
+#define EV_EFI_PLATFORM_FIRMWARE_BLOB 0x80000008U
+#define EV_EFI_HANDOFF_TABLES 0x80000009U
+#define EV_EFI_HCRTM_EVENT 0x80000010U
+#define EV_EFI_VARIABLE_AUTHORITY 0x800000E0U
+
+/*
+ * TPM_ALG_ID constants.
+ * Ref. Table 9 - Definition of (UINT16) TPM_ALG_ID Constants
+ * Trusted Platform Module Library. Part 2: Structures
+ */
+#define TPM_ALG_SHA256 0x000B
+#define TPM_ALG_SHA384 0x000C
+#define TPM_ALG_SHA512 0x000D
+
+/* TCG Platform Type */
+#define PLATFORM_CLASS_CLIENT 0
+#define PLATFORM_CLASS_SERVER 1
+
+enum {
+	/*
+	 * SRTM, BIOS, Host Platform Extensions, Embedded
+	 * Option ROMs and PI Drivers
+	 */
+	PCR_0 = 0,
+	/* Host Platform Configuration */
+	PCR_1,
+	/* UEFI driver and application Code */
+	PCR_2,
+	/* UEFI driver and application Configuration and Data */
+	PCR_3,
+	/* UEFI Boot Manager Code (usually the MBR) and Boot Attempts */
+	PCR_4,
+	/*
+	 * Boot Manager Code Configuration and Data (for use
+	 * by the Boot Manager Code) and GPT/Partition Table
+	 */
+	PCR_5,
+	/* Host Platform Manufacturer Specific */
+	PCR_6,
+	/* Secure Boot Policy */
+	PCR_7,
+	/* 8-15: Defined for use by the Static OS */
+	PCR_8,
+	/* Debug */
+	PCR_16 = 16,
+
+	/* D-CRTM-measurements by DRTM implementation */
+	PCR_17 = 17,
+	/* DCE measurements by DRTM implementation */
+	PCR_18 = 18
+};
+
+#pragma pack(push, 1)
+
+/*
+ * PCR Event Header
+ * TCG EFI Protocol Specification
+ * 5.3 Event Log Header
+ */
+typedef struct {
+	/* PCRIndex:
+	 * The PCR Index to which this event is extended
+	 */
+	uint32_t pcr_index;
+
+	/* EventType:
+	 * SHALL be an EV_NO_ACTION event
+	 */
+	uint32_t event_type;
+
+	/* SHALL be 20 Bytes of 0x00 */
+	uint8_t digest[SHA1_DIGEST_SIZE];
+
+	/* The size of the event */
+	uint32_t event_size;
+
+	/* SHALL be a TCG_EfiSpecIdEvent */
+	uint8_t event[]; /* [event_data_size] */
+} tcg_pcr_event_t;
+
+/*
+ * Log Header Entry Data
+ * Ref. Table 14 TCG_EfiSpecIdEventAlgorithmSize
+ * TCG PC Client Platform Firmware Profile 9.4.5.1
+ */
+typedef struct {
+	/* Algorithm ID (hashAlg) of the Hash used by BIOS */
+	uint16_t algorithm_id;
+
+	/* The size of the digest produced by the implemented Hash algorithm */
+	uint16_t digest_size;
+} id_event_algorithm_size_t;
+
+/*
+ * TCG_EfiSpecIdEvent structure
+ * Ref. Table 15 TCG_EfiSpecIdEvent
+ * TCG PC Client Platform Firmware Profile 9.4.5.1
+ */
+typedef struct {
+	/*
+	 * The NUL-terminated ASCII string "Spec ID Event03".
+	 * SHALL be set to {0x53, 0x70, 0x65, 0x63, 0x20, 0x49, 0x44,
+	 * 0x20, 0x45, 0x76, 0x65, 0x6e, 0x74, 0x30, 0x33, 0x00}.
+	 */
+	uint8_t signature[16];
+
+	/*
+	 * The value for the Platform Class.
+	 * The enumeration is defined in the TCG ACPI Specification Client
+	 * Common Header.
+	 */
+	uint32_t platform_class;
+
+	/*
+	 * The PC Client Platform Profile Specification minor version number
+	 * this BIOS supports.
+	 * Any BIOS supporting this version (2.0) MUST set this value to 0x00.
+	 */
+	uint8_t spec_version_minor;
+
+	/*
+	 * The PC Client Platform Profile Specification major version number
+	 * this BIOS supports.
+	 * Any BIOS supporting this version (2.0) MUST set this value to 0x02.
+	 */
+	uint8_t spec_version_major;
+
+	/*
+	 * The PC Client Platform Profile Specification errata version number
+	 * this BIOS supports.
+	 * Any BIOS supporting this version (2.0) MUST set this value to 0x02.
+	 */
+	uint8_t spec_errata;
+
+	/*
+	 * Specifies the size of the UINTN fields used in various data
+	 * structures used in this specification.
+	 * 0x01 indicates UINT32 and 0x02 indicates UINT64.
+	 */
+	uint8_t uintn_size;
+
+	/*
+	 * The number of Hash algorithms in the digestSizes field.
+	 * This field MUST be set to a value of 0x01 or greater.
+	 */
+	uint32_t number_of_algorithms;
+
+	/*
+	 * Each TCG_EfiSpecIdEventAlgorithmSize SHALL contain an algorithmId
+	 * and digestSize for each hash algorithm used in the TCG_PCR_EVENT2
+	 * structure, the first of which is a Hash algorithmID and the second
+	 * is the size of the respective digest.
+	 */
+	id_event_algorithm_size_t digest_size[]; /* number_of_algorithms */
+} id_event_struct_header_t;
+
+typedef struct {
+	/*
+	 * Size in bytes of the VendorInfo field.
+	 * Maximum value MUST be FFh bytes.
+	 */
+	uint8_t vendor_info_size;
+
+	/*
+	 * Provided for use by Platform Firmware implementer. The value might
+	 * be used, for example, to provide more detailed information about the
+	 * specific BIOS such as BIOS revision numbers, etc. The values within
+	 * this field are not standardized and are implementer-specific.
+	 * Platform-specific or -unique information MUST NOT be provided in
+	 * this field.
+	 *
+	 */
+	uint8_t vendor_info[]; /* [vendorInfoSize] */
+} id_event_struct_data_t;
+
+typedef struct {
+	id_event_struct_header_t struct_header;
+	id_event_struct_data_t struct_data;
+} id_event_struct_t;
+
+typedef struct {
+	tcg_pcr_event_t header;
+	id_event_struct_header_t struct_header;
+} id_event_headers_t;
+
+/* TPMT_HA Structure */
+typedef struct {
+	/* Selector of the hash contained in the digest that implies
+	 * the size of the digest
+	 */
+	uint16_t algorithm_id; /* AlgorithmId */
+
+	/* Digest, depends on AlgorithmId */
+	uint8_t digest[]; /* Digest[] */
+} tpmt_ha;
+
+/*
+ * TPML_DIGEST_VALUES Structure
+ */
+typedef struct {
+	/* The number of digests in the list */
+	uint32_t count; /* Count */
+
+	/* The list of tagged digests, as sent to the TPM as part of a
+	 * TPM2_PCR_Extend or as received from a TPM2_PCR_Event command
+	 */
+	tpmt_ha digests[]; /* Digests[Count] */
+} tpml_digest_values;
+
+/*
+ * TCG_PCR_EVENT2 header
+ */
+typedef struct {
+	/* The PCR Index to which this event was extended */
+	uint32_t pcr_index; /* PCRIndex */
+
+	/* Type of event */
+	uint32_t event_type; /* EventType */
+
+	/* Digests:
+	 * A counted list of tagged digests, which contain the digest of
+	 * the event data (or external data) for all active PCR banks
+	 */
+	tpml_digest_values digests; /* Digests */
+} event2_header_t;
+
+typedef struct event2_data {
+	/* The size of the event data */
+	uint32_t event_size; /* EventSize */
+
+	/* The data of the event */
+	uint8_t event[]; /* Event[EventSize] */
+} event2_data_t;
+
+/*
+ * Startup Locality Event
+ * Ref. TCG PC Client Platform Firmware Profile 9.4.5.3
+ */
+typedef struct {
+	/*
+	 * The NUL-terminated ASCII string "StartupLocality" SHALL be
+	 * set to {0x53 0x74 0x61 0x72 0x74 0x75 0x70 0x4C 0x6F 0x63
+	 * 0x61 0x6C 0x69 0x74 0x79 0x00}
+	 */
+	uint8_t signature[16];
+
+	/* The Locality Indicator which sent the TPM2_Startup command */
+	uint8_t startup_locality;
+} startup_locality_event_t;
+
+#pragma pack(pop)
+
+#endif /* TCG_H */