TF-A: Add Event Log for Measured Boot

This patch adds support for Event Log generation required
for Measured Boot functionality.

Change-Id: I34f05a33565e6659e78499d62cc6fb00b7d6c2dc
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
diff --git a/drivers/auth/mbedtls/mbedtls_common.mk b/drivers/auth/mbedtls/mbedtls_common.mk
index 564a4c9..94f2f59 100644
--- a/drivers/auth/mbedtls/mbedtls_common.mk
+++ b/drivers/auth/mbedtls/mbedtls_common.mk
@@ -75,19 +75,10 @@
 
 ifeq (${HASH_ALG}, sha384)
     TF_MBEDTLS_HASH_ALG_ID	:=	TF_MBEDTLS_SHA384
-    MBEDTLS_MD_ID		:=	MBEDTLS_MD_SHA384
-    TPM_ALG_ID			:=	TPM_ALG_SHA384
-    TCG_DIGEST_SIZE		:=	48
 else ifeq (${HASH_ALG}, sha512)
     TF_MBEDTLS_HASH_ALG_ID	:=	TF_MBEDTLS_SHA512
-    MBEDTLS_MD_ID		:=	MBEDTLS_MD_SHA512
-    TPM_ALG_ID			:=	TPM_ALG_SHA512
-    TCG_DIGEST_SIZE		:=	64
 else
     TF_MBEDTLS_HASH_ALG_ID	:=	TF_MBEDTLS_SHA256
-    MBEDTLS_MD_ID		:=	MBEDTLS_MD_SHA256
-    TPM_ALG_ID			:=	TPM_ALG_SHA256
-    TCG_DIGEST_SIZE		:=	32
 endif
 
 ifeq (${TF_MBEDTLS_KEY_ALG},ecdsa)
@@ -112,11 +103,6 @@
 $(eval $(call add_define,TF_MBEDTLS_HASH_ALG_ID))
 $(eval $(call add_define,TF_MBEDTLS_USE_AES_GCM))
 
-# Set definitions for measured boot driver
-$(eval $(call add_define,MBEDTLS_MD_ID))
-$(eval $(call add_define,TPM_ALG_ID))
-$(eval $(call add_define,TCG_DIGEST_SIZE))
-
 $(eval $(call MAKE_LIB,mbedtls))
 
 endif
diff --git a/drivers/measured_boot/event_log.c b/drivers/measured_boot/event_log.c
new file mode 100644
index 0000000..0042c96
--- /dev/null
+++ b/drivers/measured_boot/event_log.c
@@ -0,0 +1,406 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <arch_helpers.h>
+
+#include <common/bl_common.h>
+#include <common/debug.h>
+#include <drivers/auth/crypto_mod.h>
+#include <drivers/measured_boot/event_log.h>
+#include <mbedtls/md.h>
+
+#include <plat/common/platform.h>
+
+/* Event Log data */
+static uint8_t event_log[EVENT_LOG_SIZE];
+
+/* End of Event Log */
+#define	EVENT_LOG_END	((uintptr_t)event_log + sizeof(event_log) - 1U)
+
+CASSERT(sizeof(event_log) >= LOG_MIN_SIZE, assert_event_log_size);
+
+/* Pointer in event_log[] */
+static uint8_t *log_ptr = event_log;
+
+/* Pointer to measured_boot_data_t */
+const static measured_boot_data_t *plat_data_ptr;
+
+static uintptr_t tos_fw_config_base;
+static uintptr_t nt_fw_config_base;
+
+/* TCG_EfiSpecIdEvent */
+static const id_event_headers_t id_event_header = {
+	.header = {
+		.pcr_index = PCR_0,
+		.event_type = EV_NO_ACTION,
+		.digest = {0},
+		.event_size = (uint32_t)(sizeof(id_event_struct_t) +
+				(sizeof(id_event_algorithm_size_t) *
+				HASH_ALG_COUNT))
+	},
+
+	.struct_header = {
+		.signature = TCG_ID_EVENT_SIGNATURE_03,
+		.platform_class = PLATFORM_CLASS_CLIENT,
+		.spec_version_minor = TCG_SPEC_VERSION_MINOR_TPM2,
+		.spec_version_major = TCG_SPEC_VERSION_MAJOR_TPM2,
+		.spec_errata = TCG_SPEC_ERRATA_TPM2,
+		.uintn_size = (uint8_t)(sizeof(unsigned int) /
+					sizeof(uint32_t)),
+		.number_of_algorithms = HASH_ALG_COUNT
+	}
+};
+
+static const event2_header_t locality_event_header = {
+		/*
+		 * All EV_NO_ACTION events SHALL set
+		 * TCG_PCR_EVENT2.pcrIndex = 0, unless otherwise specified
+		 */
+		.pcr_index = PCR_0,
+
+		/*
+		 * All EV_NO_ACTION events SHALL set
+		 * TCG_PCR_EVENT2.eventType = 03h
+		 */
+		.event_type = EV_NO_ACTION,
+
+		/*
+		 * All EV_NO_ACTION events SHALL set
+		 * TCG_PCR_EVENT2.digests to all
+		 * 0x00's for each allocated Hash algorithm
+		 */
+		.digests = {
+			.count = HASH_ALG_COUNT
+		}
+};
+
+/* Platform's table with platform specific image IDs, names and PCRs */
+static const image_data_t plat_images_data[] = {
+	{ BL2_IMAGE_ID, BL2_STRING, PCR_0 },		/* Reserved for BL2 */
+	{ INVALID_ID, NULL, (unsigned int)(-1) }	/* Terminator */
+};
+
+static const measured_boot_data_t plat_measured_boot_data = {
+	plat_images_data,
+	NULL,	/* platform_set_nt_fw_info */
+	NULL	/* platform_set_tos_fw_info */
+};
+
+/*
+ * Function retuns pointer to platform's measured_boot_data_t structure
+ *
+ * Must be overridden in the platform code
+ */
+#pragma weak plat_get_measured_boot_data
+
+const measured_boot_data_t *plat_get_measured_boot_data(void)
+{
+	return &plat_measured_boot_data;
+}
+
+/*
+ * Add TCG_PCR_EVENT2 event
+ *
+ * @param[in] hash	Pointer to hash data of TCG_DIGEST_SIZE bytes
+ * @param[in] image_ptr	Pointer to image_data_t structure
+ * @return:
+ *	0 = success
+ *    < 0 = error code
+ */
+static int add_event2(const uint8_t *hash, const image_data_t *image_ptr)
+{
+	void *ptr = log_ptr;
+	uint32_t name_len;
+	uint32_t size_of_event;
+
+	assert(image_ptr != NULL);
+	assert(image_ptr->name != NULL);
+
+	name_len = (uint32_t)strlen(image_ptr->name) + 1U;
+	size_of_event = name_len + (uint32_t)EVENT2_HDR_SIZE;
+
+	/* Check for space in Event Log buffer */
+	if (((uintptr_t)ptr + size_of_event) > EVENT_LOG_END) {
+		ERROR("%s(): Event Log is short of memory", __func__);
+		return -ENOMEM;
+	}
+
+	/*
+	 * As per TCG specifications, firmware components that are measured
+	 * into PCR[0] must be logged in the event log using the event type
+	 * EV_POST_CODE.
+	 */
+	/* TCG_PCR_EVENT2.PCRIndex */
+	((event2_header_t *)ptr)->pcr_index = image_ptr->pcr;
+
+	/* TCG_PCR_EVENT2.EventType */
+	((event2_header_t *)ptr)->event_type = EV_POST_CODE;
+
+	/* TCG_PCR_EVENT2.Digests.Count */
+	ptr = (uint8_t *)ptr + offsetof(event2_header_t, digests);
+	((tpml_digest_values *)ptr)->count = HASH_ALG_COUNT;
+
+	/* TCG_PCR_EVENT2.Digests[] */
+	ptr = (uint8_t *)ptr + offsetof(tpml_digest_values, digests);
+
+	/* TCG_PCR_EVENT2.Digests[].AlgorithmId */
+	((tpmt_ha *)ptr)->algorithm_id = TPM_ALG_ID;
+
+	/* TCG_PCR_EVENT2.Digests[].Digest[] */
+	ptr = (uint8_t *)ptr + offsetof(tpmt_ha, digest);
+
+	/* Check for space in Event Log buffer */
+	if (((uintptr_t)ptr + TCG_DIGEST_SIZE) > EVENT_LOG_END) {
+		ERROR("%s(): Event Log is short of memory", __func__);
+		return -ENOMEM;
+	}
+
+	if (hash == NULL) {
+		/* Get BL2 hash from DTB */
+		bl2_plat_get_hash(ptr);
+	} else {
+		/* Copy digest */
+		(void)memcpy(ptr, (const void *)hash, TCG_DIGEST_SIZE);
+	}
+
+	/* TCG_PCR_EVENT2.EventSize */
+	ptr = (uint8_t *)ptr + TCG_DIGEST_SIZE;
+	((event2_data_t *)ptr)->event_size = name_len;
+
+	/* Copy event data to TCG_PCR_EVENT2.Event */
+	(void)memcpy((void *)(((event2_data_t *)ptr)->event),
+			(const void *)image_ptr->name, name_len);
+
+	/* End of event data */
+	log_ptr = (uint8_t *)ptr + offsetof(event2_data_t, event) + name_len;
+
+	return 0;
+}
+
+/*
+ * Init Event Log
+ *
+ * Initialises Event Log by writing Specification ID and
+ * Startup Locality events.
+ */
+void event_log_init(void)
+{
+	const char locality_signature[] = TCG_STARTUP_LOCALITY_SIGNATURE;
+	const uint8_t *start_ptr;
+	void *ptr = event_log;
+
+	/* Get pointer to platform's measured_boot_data_t structure */
+	plat_data_ptr = plat_get_measured_boot_data();
+
+	/*
+	 * Add Specification ID Event first
+	 *
+	 * Copy TCG_EfiSpecIDEventStruct structure header
+	 */
+	(void)memcpy(ptr, (const void *)&id_event_header,
+			sizeof(id_event_header));
+	ptr = (uint8_t *)ptr + sizeof(id_event_header);
+
+	/* TCG_EfiSpecIdEventAlgorithmSize structure */
+	((id_event_algorithm_size_t *)ptr)->algorithm_id = TPM_ALG_ID;
+	((id_event_algorithm_size_t *)ptr)->digest_size = TCG_DIGEST_SIZE;
+	ptr = (uint8_t *)ptr + sizeof(id_event_algorithm_size_t);
+
+	/*
+	 * TCG_EfiSpecIDEventStruct.vendorInfoSize
+	 * No vendor data
+	 */
+	((id_event_struct_data_t *)ptr)->vendor_info_size = 0;
+	ptr = (uint8_t *)ptr + offsetof(id_event_struct_data_t, vendor_info);
+	if ((uintptr_t)ptr != ((uintptr_t)event_log + ID_EVENT_SIZE)) {
+		panic();
+	}
+
+	start_ptr = (uint8_t *)ptr;
+
+	/*
+	 * The Startup Locality event should be placed in the log before
+	 * any event which extends PCR[0].
+	 *
+	 * Ref. TCG PC Client Platform Firmware Profile 9.4.5.3
+	 */
+
+	/* Copy Startup Locality Event Header */
+	(void)memcpy(ptr, (const void *)&locality_event_header,
+			sizeof(locality_event_header));
+	ptr = (uint8_t *)ptr + sizeof(locality_event_header);
+
+	/* TCG_PCR_EVENT2.Digests[].AlgorithmId */
+	((tpmt_ha *)ptr)->algorithm_id = TPM_ALG_ID;
+
+	/* TCG_PCR_EVENT2.Digests[].Digest[] */
+	(void)memset(&((tpmt_ha *)ptr)->digest, 0, TPM_ALG_ID);
+	ptr = (uint8_t *)ptr + offsetof(tpmt_ha, digest) + TCG_DIGEST_SIZE;
+
+	/* TCG_PCR_EVENT2.EventSize */
+	((event2_data_t *)ptr)->event_size =
+		(uint32_t)sizeof(startup_locality_event_t);
+	ptr = (uint8_t *)ptr + offsetof(event2_data_t, event);
+
+	/* TCG_EfiStartupLocalityEvent.Signature */
+	(void)memcpy(ptr, (const void *)locality_signature,
+		sizeof(TCG_STARTUP_LOCALITY_SIGNATURE));
+
+	/*
+	 * TCG_EfiStartupLocalityEvent.StartupLocality = 0:
+	 * the platform's boot firmware
+	 */
+	((startup_locality_event_t *)ptr)->startup_locality = 0U;
+	ptr = (uint8_t *)ptr + sizeof(startup_locality_event_t);
+	if ((uintptr_t)ptr != ((uintptr_t)start_ptr + LOC_EVENT_SIZE)) {
+		panic();
+	}
+
+	log_ptr = (uint8_t *)ptr;
+
+	/* Add BL2 event */
+	if (add_event2(NULL, plat_data_ptr->images_data) != 0) {
+		panic();
+	}
+}
+
+/*
+ * Calculate and write hash of image, configuration data, etc.
+ * to Event Log.
+ *
+ * @param[in] data_base		Address of data
+ * @param[in] data_size		Size of data
+ * @param[in] data_id		Data ID
+ * @return:
+ *	0 = success
+ *    < 0 = error
+ */
+int tpm_record_measurement(uintptr_t data_base, uint32_t data_size,
+			   uint32_t data_id)
+{
+	const image_data_t *data_ptr = plat_data_ptr->images_data;
+	unsigned char hash_data[MBEDTLS_MD_MAX_SIZE];
+	int rc;
+
+	/* Check if image_id is supported */
+	while (data_ptr->id != data_id) {
+		if ((data_ptr++)->id == INVALID_ID) {
+			ERROR("%s(): image_id %u not supported\n",
+				__func__, data_id);
+			return -EINVAL;
+		}
+	}
+
+	if (data_id == TOS_FW_CONFIG_ID) {
+		tos_fw_config_base = data_base;
+	} else if (data_id == NT_FW_CONFIG_ID) {
+		nt_fw_config_base = data_base;
+	} else {
+		/* No action */
+	}
+
+	/* Calculate hash */
+	rc = crypto_mod_calc_hash((unsigned int)MBEDTLS_MD_ID,
+				(void *)data_base, data_size, hash_data);
+	if (rc != 0) {
+		return rc;
+	}
+
+	return add_event2(hash_data, data_ptr);
+}
+
+/*
+ * Finalise Event Log
+ *
+ * @param[out] log_addr	Pointer to return Event Log address
+ * @param[out] log_size	Pointer to return Event Log size
+ * @return:
+ *	0 = success
+ *    < 0 = error code
+ */
+int event_log_finalise(uint8_t **log_addr, size_t *log_size)
+{
+	/* Event Log size */
+	size_t num_bytes = (uintptr_t)log_ptr - (uintptr_t)event_log;
+	int rc;
+
+	assert(log_addr != NULL);
+	assert(log_size != NULL);
+
+	if (nt_fw_config_base == 0UL) {
+		ERROR("%s(): %s_FW_CONFIG not loaded\n", __func__, "NT");
+		return -ENOENT;
+	}
+
+	/*
+	 * Set Event Log data in NT_FW_CONFIG and
+	 * get Event Log address in Non-Secure memory
+	 */
+	if (plat_data_ptr->set_nt_fw_info != NULL) {
+
+		/* Event Log address in Non-Secure memory */
+		uintptr_t ns_log_addr;
+
+		rc = plat_data_ptr->set_nt_fw_info(
+				nt_fw_config_base,
+#ifdef SPD_opteed
+				(uintptr_t)event_log,
+#endif
+				num_bytes, &ns_log_addr);
+		if (rc != 0) {
+			ERROR("%s(): Unable to update %s_FW_CONFIG\n",
+						__func__, "NT");
+			return rc;
+		}
+
+		/* Copy Event Log to Non-secure memory */
+		(void)memcpy((void *)ns_log_addr, (const void *)event_log,
+				num_bytes);
+
+		/* Ensure that the Event Log is visible in Non-secure memory */
+		flush_dcache_range(ns_log_addr, num_bytes);
+
+		/* Return Event Log address in Non-Secure memory */
+		*log_addr = (uint8_t *)ns_log_addr;
+
+	} else {
+		INFO("%s(): set_%s_fw_info not set\n", __func__, "nt");
+
+		/* Return Event Log address in Secure memory */
+		*log_addr = event_log;
+	}
+
+	if (tos_fw_config_base != 0UL) {
+		if (plat_data_ptr->set_tos_fw_info != NULL) {
+
+			/* Set Event Log data in TOS_FW_CONFIG */
+			rc = plat_data_ptr->set_tos_fw_info(
+						tos_fw_config_base,
+						(uintptr_t)event_log,
+						num_bytes);
+			if (rc != 0) {
+				ERROR("%s(): Unable to update %s_FW_CONFIG\n",
+						__func__, "TOS");
+				return rc;
+			}
+		} else {
+			INFO("%s(): set_%s_fw_info not set\n", __func__, "tos");
+		}
+	} else {
+		INFO("%s(): %s_FW_CONFIG not loaded\n", __func__, "TOS");
+	}
+
+	/* Ensure that the Event Log is visible in Secure memory */
+	flush_dcache_range((uintptr_t)event_log, num_bytes);
+
+	/* Return Event Log size */
+	*log_size = num_bytes;
+
+	return 0;
+}
diff --git a/drivers/measured_boot/event_print.c b/drivers/measured_boot/event_print.c
new file mode 100644
index 0000000..ed970b8
--- /dev/null
+++ b/drivers/measured_boot/event_print.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <common/debug.h>
+#include <drivers/measured_boot/event_log.h>
+
+#if LOG_LEVEL >= EVENT_LOG_LEVEL
+
+/*
+ * Print TCG_EfiSpecIDEventStruct
+ *
+ * @param[in/out] log_addr	Pointer to Event Log
+ * @param[in/out] log_size	Pointer to Event Log size
+ */
+static void id_event_print(uint8_t **log_addr, size_t *log_size)
+{
+	unsigned int i;
+	uint8_t info_size, *info_size_ptr;
+	void *ptr = *log_addr;
+	id_event_headers_t *event = (id_event_headers_t *)ptr;
+	id_event_algorithm_size_t *alg_ptr;
+	uint32_t event_size, number_of_algorithms;
+	size_t digest_len;
+#if ENABLE_ASSERTIONS
+	const uint8_t *end_ptr = *log_addr + *log_size;
+	bool valid = true;
+#endif
+
+	assert(*log_size >= sizeof(id_event_headers_t));
+
+	/* The fields of the event log header are defined to be PCRIndex of 0,
+	 * EventType of EV_NO_ACTION, Digest of 20 bytes of 0, and
+	 * Event content defined as TCG_EfiSpecIDEventStruct.
+	 */
+	LOG_EVENT("TCG_EfiSpecIDEvent:\n");
+	LOG_EVENT("  PCRIndex           : %u\n", event->header.pcr_index);
+	assert(event->header.pcr_index == (uint32_t)PCR_0);
+
+	LOG_EVENT("  EventType          : %u\n", event->header.event_type);
+	assert(event->header.event_type == EV_NO_ACTION);
+
+	LOG_EVENT("  Digest             :");
+	for (i = 0U; i < sizeof(event->header.digest); ++i) {
+		uint8_t val = event->header.digest[i];
+
+		(void)printf(" %02x", val);
+		if ((i & U(0xF)) == 0U) {
+			(void)printf("\n");
+			LOG_EVENT("\t\t      :");
+		}
+#if ENABLE_ASSERTIONS
+		if (val != 0U) {
+			valid = false;
+		}
+#endif
+	}
+	if ((i & U(0xF)) != 0U) {
+		(void)printf("\n");
+	}
+
+	assert(valid);
+
+	/* EventSize */
+	event_size = event->header.event_size;
+	LOG_EVENT("  EventSize          : %u\n", event_size);
+
+	LOG_EVENT("  Signature          : %s\n",
+			event->struct_header.signature);
+	LOG_EVENT("  PlatformClass      : %u\n",
+			event->struct_header.platform_class);
+	LOG_EVENT("  SpecVersion        : %u.%u.%u\n",
+			event->struct_header.spec_version_major,
+			event->struct_header.spec_version_minor,
+			event->struct_header.spec_errata);
+	LOG_EVENT("  UintnSize          : %u\n",
+			event->struct_header.uintn_size);
+
+	/* NumberOfAlgorithms */
+	number_of_algorithms = event->struct_header.number_of_algorithms;
+	LOG_EVENT("  NumberOfAlgorithms : %u\n", number_of_algorithms);
+
+	/* Address of DigestSizes[] */
+	alg_ptr = event->struct_header.digest_size;
+
+	/* Size of DigestSizes[] */
+	digest_len = number_of_algorithms * sizeof(id_event_algorithm_size_t);
+	assert(((uint8_t *)alg_ptr + digest_len) <= end_ptr);
+
+	LOG_EVENT("  DigestSizes        :\n");
+	for (i = 0U; i < number_of_algorithms; ++i) {
+		LOG_EVENT("    #%u AlgorithmId   : SHA", i);
+		uint16_t algorithm_id = alg_ptr[i].algorithm_id;
+
+		switch (algorithm_id) {
+		case TPM_ALG_SHA256:
+			(void)printf("256\n");
+			break;
+		case TPM_ALG_SHA384:
+			(void)printf("384\n");
+			break;
+		case TPM_ALG_SHA512:
+			(void)printf("512\n");
+			break;
+		default:
+			(void)printf("?\n");
+			ERROR("Algorithm 0x%x not found\n", algorithm_id);
+			assert(false);
+		}
+
+		LOG_EVENT("       DigestSize    : %u\n",
+					alg_ptr[i].digest_size);
+	}
+
+	/* Address of VendorInfoSize */
+	info_size_ptr = (uint8_t *)alg_ptr + digest_len;
+	assert(info_size_ptr <= end_ptr);
+
+	info_size = *info_size_ptr++;
+	LOG_EVENT("  VendorInfoSize     : %u\n", info_size);
+
+	/* Check VendorInfo end address */
+	assert((info_size_ptr + info_size) <= end_ptr);
+
+	/* Check EventSize */
+	assert(event_size == (sizeof(id_event_struct_t) +
+				digest_len + info_size));
+	if (info_size != 0U) {
+		LOG_EVENT("  VendorInfo         :");
+		for (i = 0U; i < info_size; ++i) {
+			(void)printf(" %02x", *info_size_ptr++);
+		}
+		(void)printf("\n");
+	}
+
+	*log_size -= (uintptr_t)info_size_ptr - (uintptr_t)*log_addr;
+	*log_addr = info_size_ptr;
+}
+
+/*
+ * Print TCG_PCR_EVENT2
+ *
+ * @param[in/out] log_addr	Pointer to Event Log
+ * @param[in/out] log_size	Pointer to Event Log size
+ */
+static void event2_print(uint8_t **log_addr, size_t *log_size)
+{
+	uint32_t event_size, count;
+	size_t sha_size, digests_size = 0U;
+	void *ptr = *log_addr;
+#if ENABLE_ASSERTIONS
+	const uint8_t *end_ptr = *log_addr + *log_size;
+#endif
+
+	assert(*log_size >= sizeof(event2_header_t));
+
+	LOG_EVENT("PCR_Event2:\n");
+	LOG_EVENT("  PCRIndex           : %u\n",
+			((event2_header_t *)ptr)->pcr_index);
+	LOG_EVENT("  EventType          : %u\n",
+			((event2_header_t *)ptr)->event_type);
+
+	count = ((event2_header_t *)ptr)->digests.count;
+	LOG_EVENT("  Digests Count      : %u\n", count);
+
+	/* Address of TCG_PCR_EVENT2.Digests[] */
+	ptr = (uint8_t *)ptr + sizeof(event2_header_t);
+	assert(((uintptr_t)ptr <= (uintptr_t)end_ptr) && (count != 0U));
+
+	for (unsigned int i = 0U; i < count; ++i) {
+		/* Check AlgorithmId address */
+		assert(((uint8_t *)ptr + offsetof(tpmt_ha, digest)) <= end_ptr);
+
+		LOG_EVENT("    #%u AlgorithmId   : SHA", i);
+		switch (((tpmt_ha *)ptr)->algorithm_id) {
+		case TPM_ALG_SHA256:
+			sha_size = SHA256_DIGEST_SIZE;
+			(void)printf("256\n");
+			break;
+		case TPM_ALG_SHA384:
+			sha_size = SHA384_DIGEST_SIZE;
+			(void)printf("384\n");
+			break;
+		case TPM_ALG_SHA512:
+			sha_size = SHA512_DIGEST_SIZE;
+			(void)printf("512\n");
+			break;
+		default:
+			(void)printf("?\n");
+			ERROR("Algorithm 0x%x not found\n",
+				((tpmt_ha *)ptr)->algorithm_id);
+			panic();
+		}
+
+		/* End of Digest[] */
+		ptr = (uint8_t *)ptr + offsetof(tpmt_ha, digest);
+		assert(((uint8_t *)ptr + sha_size) <= end_ptr);
+
+		/* Total size of all digests */
+		digests_size += sha_size;
+
+		LOG_EVENT("       Digest        :");
+		for (unsigned int j = 0U; j < sha_size; ++j) {
+			(void)printf(" %02x", *(uint8_t *)ptr++);
+			if ((j & U(0xF)) == U(0xF)) {
+				(void)printf("\n");
+				if (j < (sha_size - 1U)) {
+					LOG_EVENT("\t\t      :");
+				}
+			}
+		}
+	}
+
+	/* TCG_PCR_EVENT2.EventSize */
+	assert(((uint8_t *)ptr + offsetof(event2_data_t, event)) <= end_ptr);
+
+	event_size = ((event2_data_t *)ptr)->event_size;
+	LOG_EVENT("  EventSize          : %u\n", event_size);
+
+	/* Address of TCG_PCR_EVENT2.Event[EventSize] */
+	ptr = (uint8_t *)ptr + offsetof(event2_data_t, event);
+
+	/* End of TCG_PCR_EVENT2.Event[EventSize] */
+	assert(((uint8_t *)ptr + event_size) <= end_ptr);
+
+	if ((event_size == sizeof(startup_locality_event_t)) &&
+	     (strcmp((const char *)ptr, TCG_STARTUP_LOCALITY_SIGNATURE) == 0)) {
+		LOG_EVENT("  Signature          : %s\n",
+			((startup_locality_event_t *)ptr)->signature);
+		LOG_EVENT("  StartupLocality    : %u\n",
+			((startup_locality_event_t *)ptr)->startup_locality);
+	} else {
+		LOG_EVENT("  Event              : %s\n", (uint8_t *)ptr);
+	}
+
+	*log_size -= (uintptr_t)ptr + event_size - (uintptr_t)*log_addr;
+	*log_addr = (uint8_t *)ptr + event_size;
+}
+#endif	/* LOG_LEVEL >= EVENT_LOG_LEVEL */
+
+/*
+ * Print Event Log
+ *
+ * @param[in]	log_addr	Pointer to Event Log
+ * @param[in]	log_size	Event Log size
+ */
+void dump_event_log(uint8_t *log_addr, size_t log_size)
+{
+#if LOG_LEVEL >= EVENT_LOG_LEVEL
+	assert(log_addr != NULL);
+
+	/* Print TCG_EfiSpecIDEvent */
+	id_event_print(&log_addr, &log_size);
+
+	while (log_size != 0U) {
+		event2_print(&log_addr, &log_size);
+	}
+#endif
+}
diff --git a/drivers/measured_boot/measured_boot.c b/drivers/measured_boot/measured_boot.c
new file mode 100644
index 0000000..37fddfb
--- /dev/null
+++ b/drivers/measured_boot/measured_boot.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <common/debug.h>
+#include <drivers/measured_boot/measured_boot.h>
+
+/*
+ * Init Measured Boot driver
+ *
+ * Initialises Event Log.
+ */
+void measured_boot_init(void)
+{
+	event_log_init();
+}
+
+/*
+ * Finish Measured Boot driver
+ *
+ * Finalises Event Log and dumps the records to the debug console.
+ */
+void measured_boot_finish(void)
+{
+	uint8_t *log_addr;
+	size_t log_size;
+	int rc;
+
+	rc = event_log_finalise(&log_addr, &log_size);
+	if (rc != 0) {
+		panic();
+	}
+
+	dump_event_log(log_addr, log_size);
+}
diff --git a/drivers/measured_boot/measured_boot.mk b/drivers/measured_boot/measured_boot.mk
new file mode 100644
index 0000000..fc005d5
--- /dev/null
+++ b/drivers/measured_boot/measured_boot.mk
@@ -0,0 +1,45 @@
+#
+# Copyright (c) 2020, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+# TPM hash algorithm
+TPM_HASH_ALG			:=	sha256
+
+ifeq (${TPM_HASH_ALG}, sha512)
+    MBEDTLS_MD_ID		:=	MBEDTLS_MD_SHA512
+    TPM_ALG_ID			:=	TPM_ALG_SHA512
+    TCG_DIGEST_SIZE		:=	64U
+else ifeq (${TPM_HASH_ALG}, sha384)
+    MBEDTLS_MD_ID		:=	MBEDTLS_MD_SHA384
+    TPM_ALG_ID			:=	TPM_ALG_SHA384
+    TCG_DIGEST_SIZE		:=	48U
+else
+    MBEDTLS_MD_ID		:=	MBEDTLS_MD_SHA256
+    TPM_ALG_ID			:=	TPM_ALG_SHA256
+    TCG_DIGEST_SIZE		:=	32U
+endif
+
+# Event Log length in bytes
+EVENT_LOG_SIZE			:= 1024
+
+# Set definitions for mbed TLS library and Measured Boot driver
+$(eval $(call add_define,MBEDTLS_MD_ID))
+$(eval $(call add_define,TPM_ALG_ID))
+$(eval $(call add_define,TCG_DIGEST_SIZE))
+$(eval $(call add_define,EVENT_LOG_SIZE))
+
+ifeq (${HASH_ALG}, sha256)
+ifneq (${TPM_HASH_ALG}, sha256)
+$(eval $(call add_define,MBEDTLS_SHA512_C))
+endif
+endif
+
+MEASURED_BOOT_SRC_DIR	:= drivers/measured_boot/
+
+MEASURED_BOOT_SOURCES	:= ${MEASURED_BOOT_SRC_DIR}measured_boot.c	\
+    			   ${MEASURED_BOOT_SRC_DIR}event_log.c		\
+    			   ${MEASURED_BOOT_SRC_DIR}event_print.c
+
+BL2_SOURCES		+= ${MEASURED_BOOT_SOURCES}
diff --git a/include/drivers/measured_boot/event_log.h b/include/drivers/measured_boot/event_log.h
new file mode 100644
index 0000000..10dfbb3
--- /dev/null
+++ b/include/drivers/measured_boot/event_log.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef EVENT_LOG_H
+#define EVENT_LOG_H
+
+#include <stdint.h>
+
+#include <common/debug.h>
+#include <drivers/measured_boot/tcg.h>
+
+/*
+ * Set Event Log debug level to one of:
+ *
+ * LOG_LEVEL_ERROR
+ * LOG_LEVEL_INFO
+ * LOG_LEVEL_WARNING
+ * LOG_LEVEL_VERBOSE
+ */
+#define	EVENT_LOG_LEVEL	LOG_LEVEL_INFO
+
+#if EVENT_LOG_LEVEL   == LOG_LEVEL_ERROR
+#define	LOG_EVENT	ERROR
+#elif EVENT_LOG_LEVEL == LOG_LEVEL_NOTICE
+#define	LOG_EVENT	NOTICE
+#elif EVENT_LOG_LEVEL == LOG_LEVEL_WARNING
+#define	LOG_EVENT	WARN
+#elif EVENT_LOG_LEVEL == LOG_LEVEL_INFO
+#define	LOG_EVENT	INFO
+#elif EVENT_LOG_LEVEL == LOG_LEVEL_VERBOSE
+#define	LOG_EVENT	VERBOSE
+#else
+#error "Not supported EVENT_LOG_LEVEL"
+#endif
+
+/* Number of hashing algorithms supported */
+#define HASH_ALG_COUNT	1U
+
+#define	INVALID_ID	MAX_NUMBER_IDS
+
+#define MEMBER_SIZE(type, member) sizeof(((type *)0)->member)
+
+#define BL2_STRING			"BL_2"
+#define BL31_STRING			"BL_31"
+#define BL32_STRING			"BL_32"
+#define	BL32_EXTRA1_IMAGE_STRING	"BL32_EXTRA1_IMAGE"
+#define	BL32_EXTRA2_IMAGE_STRING	"BL32_EXTRA2_IMAGE"
+#define BL33_STRING			"BL_33"
+#define GPT_IMAGE_STRING		"GPT"
+#define HW_CONFIG_STRING		"HW_CONFIG"
+#define NT_FW_CONFIG_STRING		"NT_FW_CONFIG"
+#define SCP_BL2_IMAGE_STRING		"SCP_BL2_IMAGE"
+#define SOC_FW_CONFIG_STRING		"SOC_FW_CONFIG"
+#define STM32_IMAGE_STRING		"STM32"
+#define	TOS_FW_CONFIG_STRING		"TOS_FW_CONFIG"
+
+typedef struct {
+	unsigned int id;
+	const char *name;
+	unsigned int pcr;
+} image_data_t;
+
+typedef struct {
+	const image_data_t *images_data;
+	int (*set_nt_fw_info)(uintptr_t config_base,
+#ifdef SPD_opteed
+				uintptr_t log_addr,
+#endif
+				size_t log_size, uintptr_t *ns_log_addr);
+	int (*set_tos_fw_info)(uintptr_t config_base, uintptr_t log_addr,
+				size_t log_size);
+} measured_boot_data_t;
+
+#define	ID_EVENT_SIZE	(sizeof(id_event_headers_t) + \
+			(sizeof(id_event_algorithm_size_t) * HASH_ALG_COUNT) + \
+			sizeof(id_event_struct_data_t))
+
+#define	LOC_EVENT_SIZE	(sizeof(event2_header_t) + \
+			sizeof(tpmt_ha) + TCG_DIGEST_SIZE + \
+			sizeof(event2_data_t) + \
+			sizeof(startup_locality_event_t))
+
+#define	LOG_MIN_SIZE	(ID_EVENT_SIZE + LOC_EVENT_SIZE)
+
+#define EVENT2_HDR_SIZE	(sizeof(event2_header_t) + \
+			sizeof(tpmt_ha) + TCG_DIGEST_SIZE + \
+			sizeof(event2_data_t))
+
+/* Functions' declarations */
+void event_log_init(void);
+int event_log_finalise(uint8_t **log_addr, size_t *log_size);
+void dump_event_log(uint8_t *log_addr, size_t log_size);
+const measured_boot_data_t *plat_get_measured_boot_data(void);
+int tpm_record_measurement(uintptr_t data_base, uint32_t data_size,
+			   uint32_t data_id);
+#endif /* EVENT_LOG_H */
diff --git a/include/drivers/measured_boot/measured_boot.h b/include/drivers/measured_boot/measured_boot.h
new file mode 100644
index 0000000..f8769ab
--- /dev/null
+++ b/include/drivers/measured_boot/measured_boot.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MEASURED_BOOT_H
+#define MEASURED_BOOT_H
+
+#include <stdint.h>
+
+#include <drivers/measured_boot/event_log.h>
+
+/* Platform specific table of image IDs, names and PCRs */
+extern const image_data_t images_data[];
+
+/* Functions' declarations */
+void measured_boot_init(void);
+void measured_boot_finish(void);
+
+#endif /* MEASURED_BOOT_H */
diff --git a/include/drivers/measured_boot/tcg.h b/include/drivers/measured_boot/tcg.h
new file mode 100644
index 0000000..ab27a08
--- /dev/null
+++ b/include/drivers/measured_boot/tcg.h
@@ -0,0 +1,304 @@
+/*
+ * Copyright (c) 2020, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef TCG_H
+#define TCG_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				U(0x00000000)
+#define EV_POST_CODE				U(0x00000001)
+#define	EV_UNUSED				U(0x00000002)
+#define EV_NO_ACTION				U(0x00000003)
+#define EV_SEPARATOR				U(0x00000004)
+#define EV_ACTION				U(0x00000005)
+#define	EV_EVENT_TAG				U(0x00000006)
+#define EV_S_CRTM_CONTENTS			U(0x00000007)
+#define EV_S_CRTM_VERSION			U(0x00000008)
+#define EV_CPU_MICROCODE			U(0x00000009)
+#define EV_PLATFORM_CONFIG_FLAGS		U(0x0000000A)
+#define EV_TABLE_OF_DEVICES			U(0x0000000B)
+#define EV_COMPACT_HASH				U(0x0000000C)
+#define	EV_IPL					U(0x0000000D)
+#define	EV_IPL_PARTITION_DATA			U(0x0000000E)
+#define EV_NONHOST_CODE				U(0x0000000F)
+#define EV_NONHOST_CONFIG			U(0x00000010)
+#define EV_NONHOST_INFO				U(0x00000011)
+#define EV_OMIT_BOOT_DEVICE_EVENTS		U(0x00000012)
+#define	EV_EFI_EVENT_BASE			U(0x80000000)
+#define	EV_EFI_VARIABLE_DRIVER_CONFIG		U(0x80000001)
+#define EV_EFI_VARIABLE_BOOT			U(0x80000002)
+#define	EV_EFI_BOOT_SERVICES_APPLICATION	U(0x80000003)
+#define	EV_EFI_BOOT_SERVICES_DRIVER		U(0x80000004)
+#define	EV_EFI_RUNTIME_SERVICES_DRIVER		U(0x80000005)
+#define	EV_EFI_GPT_EVENT			U(0x80000006)
+#define	EV_EFI_ACTION				U(0x80000007)
+#define	EV_EFI_PLATFORM_FIRMWARE_BLOB		U(0x80000008)
+#define	EV_EFI_HANDOFF_TABLES			U(0x80000009)
+#define	EV_EFI_HCRTM_EVENT			U(0x80000010)
+#define	EV_EFI_VARIABLE_AUTHORITY		U(0x800000E0)
+
+/*
+ * 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
+
+/* SHA digest sizes in bytes */
+#define SHA1_DIGEST_SIZE	20
+#define SHA256_DIGEST_SIZE	32
+#define SHA384_DIGEST_SIZE	48
+#define SHA512_DIGEST_SIZE	64
+
+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
+};
+
+#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 */
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index a92bf25..96ab2d3 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -337,3 +337,9 @@
         $(error "To reclaim init code xlat tables v2 must be used")
     endif
 endif
+
+ifeq (${MEASURED_BOOT},1)
+    MEASURED_BOOT_MK := drivers/measured_boot/measured_boot.mk
+    $(info Including ${MEASURED_BOOT_MK})
+    include ${MEASURED_BOOT_MK}
+endif