[PATCH 2/3] efi_loader: Introduce eventlog support for TCG2_PROTOCOL

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

In the previous patches we only introduced a minimal subset of the
EFI_TCG2_PROTOCOL protocol implementing GetCapability().
So let's continue adding features to it, introducing the
GetEventLog() and HashLogExtendEvent() functions.

In order to do that we first need to construct the eventlog in memory,
specifically in EFI_BOOT_SERVICES_DATA memory and a configuration table
from EFI_ACPI_MEMORY_NVS.
U-Boot won't currently add any events to the log or measure any
components, but will expose the necessary EFI APIs for applications
to do so.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
---
 include/efi_api.h          |   4 +
 include/efi_tcg2.h         |  48 +++-
 lib/efi_loader/efi_setup.c |  12 +-
 lib/efi_loader/efi_tcg2.c  | 554 +++++++++++++++++++++++++++++++++++--
 4 files changed, 594 insertions(+), 24 deletions(-)

diff --git a/include/efi_api.h b/include/efi_api.h
index 5744f6aed86d..364c578a3b1b 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -356,6 +356,10 @@ struct efi_runtime_services {
 	EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e, \
 		 0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d)
 
+#define EFI_TCG2_FINAL_EVENTS_TABLE_GUID \
+	EFI_GUID(0x1e2ed096, 0x30e2, 0x4254, 0xbd, \
+		 0x89, 0x86, 0x3b, 0xbe, 0xf8, 0x23, 0x25)
+
 struct efi_configuration_table {
 	efi_guid_t guid;
 	void *table;
diff --git a/include/efi_tcg2.h b/include/efi_tcg2.h
index 86b8fe4c01af..6de86156ac4d 100644
--- a/include/efi_tcg2.h
+++ b/include/efi_tcg2.h
@@ -17,6 +17,8 @@
 
 /* TPMV2 only */
 #define TCG2_EVENT_LOG_FORMAT_TCG_2 0x00000002
+#define EFI_TCG2_EXTEND_ONLY 0x0000000000000001
+#define PE_COFF_IMAGE 0x0000000000000010
 
 /* Algorithm Registry */
 #define EFI_TCG2_BOOT_HASH_ALG_SHA1    0x00000001
@@ -25,6 +27,15 @@
 #define EFI_TCG2_BOOT_HASH_ALG_SHA512  0x00000008
 #define EFI_TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
 
+#define TPM2_SHA1_DIGEST_SIZE 20
+#define TPM2_SHA256_DIGEST_SIZE 32
+#define TPM2_SHA384_DIGEST_SIZE 48
+#define TPM2_SHA512_DIGEST_SIZE 64
+
+#define EFI_TCG2_FINAL_EVENTS_TABLE_VERSION 1
+
+#define TPM2_EVENT_LOG_SIZE 4096
+
 typedef u32 efi_tcg_event_log_bitmap;
 typedef u32 efi_tcg_event_log_format;
 typedef u32 efi_tcg_event_algorithm_bitmap;
@@ -65,6 +76,40 @@ struct efi_tcg2_boot_service_capability {
 	sizeof(struct efi_tcg2_boot_service_capability) - \
 	offsetof(struct efi_tcg2_boot_service_capability, number_of_pcr_banks)
 
+#define tcg_efi_spec_id_event_signature_03 "Spec ID Event03"
+
+#define tcg_efi_spec_id_event_spec_version_major_tpm2 2
+#define tcg_efi_spec_id_event_spec_version_minor_tpm2 0
+#define tcg_efi_spec_id_event_spec_version_errata_tpm2 0
+
+struct tcg_efi_spec_id_event_algorithm_size {
+	u16      algorithm_id;
+	u16      digest_size;
+} __packed;
+
+struct tcg_efi_spec_id_event {
+	u8 signature[16];
+	u32 platform_class;
+	u8 spec_version_minor;
+	u8 spec_version_major;
+	u8 spec_errata;
+	u8 uintn_size;
+	u32 number_of_algorithms;
+	struct tcg_efi_spec_id_event_algorithm_size digest_sizes[TPM2_NUM_PCR_BANKS];
+	u8 vendor_info_size;
+	/*
+	 * filled in with vendor_info_size
+	 * currently vendor_info_size = 0
+	 */
+	u8 vendor_info[];
+} __packed;
+
+struct efi_tcg2_final_events_table {
+	u64 version;
+	u64 number_of_events;
+	struct tcg_pcr_event2 event[];
+};
+
 struct efi_tcg2_protocol {
 	efi_status_t (EFIAPI * get_capability)(struct efi_tcg2_protocol *this,
 					       struct efi_tcg2_boot_service_capability *capability);
@@ -73,7 +118,8 @@ struct efi_tcg2_protocol {
 					     u64 *event_log_location, u64 *event_log_last_entry,
 					     bool *event_log_truncated);
 	efi_status_t (EFIAPI * hash_log_extend_event)(struct efi_tcg2_protocol *this,
-						      u64 flags, u64 data_to_hash,
+						      u64 flags,
+						      efi_physical_addr_t data_to_hash,
 						      u64 data_to_hash_len,
 						      struct efi_tcg2_event *efi_tcg_event);
 	efi_status_t (EFIAPI * submit_command)(struct efi_tcg2_protocol *this,
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index e206b60bb82c..2bb2c3c7aafa 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -157,12 +157,6 @@ efi_status_t efi_init_obj_list(void)
 			goto out;
 	}
 
-	if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
-		ret = efi_tcg2_register();
-		if (ret != EFI_SUCCESS)
-			goto out;
-	}
-
 	/* Initialize variable services */
 	ret = efi_init_variables();
 	if (ret != EFI_SUCCESS)
@@ -189,6 +183,12 @@ efi_status_t efi_init_obj_list(void)
 	if (ret != EFI_SUCCESS)
 		goto out;
 
+	if (IS_ENABLED(CONFIG_EFI_TCG2_PROTOCOL)) {
+		ret = efi_tcg2_register();
+		if (ret != EFI_SUCCESS)
+			goto out;
+	}
+
 	/* Secure boot */
 	ret = efi_init_secure_boot();
 	if (ret != EFI_SUCCESS)
diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
index 62f2f9427b6e..d65a48bc65a3 100644
--- a/lib/efi_loader/efi_tcg2.c
+++ b/lib/efi_loader/efi_tcg2.c
@@ -14,11 +14,24 @@
 #include <efi_tcg2.h>
 #include <log.h>
 #include <tpm-v2.h>
+#include <u-boot/sha1.h>
+#include <u-boot/sha256.h>
+#include <u-boot/sha512.h>
 #include <linux/unaligned/access_ok.h>
 #include <linux/unaligned/generic.h>
+#include <hexdump.h>
+
+struct event_log_buffer {
+	void *buffer;
+	void *final_buffer;
+	size_t pos; /* eventlog position */
+	size_t final_pos; /* final events config table position */
+	size_t last_event_size;
+	bool get_event_called;
+	bool truncated;
+};
 
-DECLARE_GLOBAL_DATA_PTR;
-
+static struct event_log_buffer event_log;
 /*
  * When requesting TPM2_CAP_TPM_PROPERTIES the value is on a standard offset.
  * Since the current tpm2_get_capability() response buffers starts at
@@ -30,33 +43,40 @@ DECLARE_GLOBAL_DATA_PTR;
 #define properties_offset (offsetof(struct tpml_tagged_tpm_property, tpm_property) + \
 			   offsetof(struct tpms_tagged_property, value))
 
-struct {
+static const efi_guid_t efi_guid_tcg2_protocol = EFI_TCG2_PROTOCOL_GUID;
+static const efi_guid_t efi_guid_final_events = EFI_TCG2_FINAL_EVENTS_TABLE_GUID;
+
+struct digest_info {
 	u16 hash_alg;
 	u32 hash_mask;
-} hash_algo_list[] = {
+	u16 hash_len;
+};
+
+const static struct digest_info hash_algo_list[] = {
 	{
 		TPM2_ALG_SHA1,
 		EFI_TCG2_BOOT_HASH_ALG_SHA1,
+		TPM2_SHA1_DIGEST_SIZE,
 	},
 	{
 		TPM2_ALG_SHA256,
 		EFI_TCG2_BOOT_HASH_ALG_SHA256,
+		TPM2_SHA256_DIGEST_SIZE,
 	},
 	{
 		TPM2_ALG_SHA384,
 		EFI_TCG2_BOOT_HASH_ALG_SHA384,
+		TPM2_SHA384_DIGEST_SIZE,
 	},
 	{
 		TPM2_ALG_SHA512,
 		EFI_TCG2_BOOT_HASH_ALG_SHA512,
-	},
-	{
-		TPM2_ALG_SM3_256,
-		EFI_TCG2_BOOT_HASH_ALG_SM3_256,
+		TPM2_SHA512_DIGEST_SIZE,
 	},
 };
 
 #define MAX_HASH_COUNT ARRAY_SIZE(hash_algo_list)
+
 /**
  * alg_to_mask - Get a TCG hash mask for algorithms
  *
@@ -76,7 +96,146 @@ static u32 alg_to_mask(u16 hash_alg)
 	return 0;
 }
 
-const efi_guid_t efi_guid_tcg2_protocol = EFI_TCG2_PROTOCOL_GUID;
+/**
+ * alg_to_len - Get a TCG hash len for algorithms
+ *
+ * @hash_alg: TCG defined algorithm
+ *
+ * @Return: len of chosen algorithm, 0 if the algorithm is not supported
+ */
+static u16 alg_to_len(u16 hash_alg)
+{
+	int i;
+
+	for (i = 0; i < MAX_HASH_COUNT; i++) {
+		if (hash_algo_list[i].hash_alg == hash_alg)
+			return hash_algo_list[i].hash_len;
+	}
+
+	return 0;
+}
+
+static u32 tcg_event_final_size(struct tpml_digest_values *digest_list)
+{
+	u32 len;
+	int i;
+
+	len = offsetof(struct tcg_pcr_event2, digests);
+	len += offsetof(struct tpml_digest_values, digests);
+	for (i = 0; i < digest_list->count; i++) {
+		u16 hash_alg = digest_list->digests[i].hash_alg;
+
+		len += offsetof(struct tpmt_ha, digest);
+		len += alg_to_len(hash_alg);
+	}
+	len += sizeof(u32); /* tcg_pcr_event2 event_size*/
+
+	return len;
+}
+
+/* tcg2_pcr_extend - Extend PCRs for a TPM2 device for a given tpml_digest_values
+ *
+ * @dev:		device
+ * @digest_list:	list of digest algorithms to extend
+ *
+ * @Return: status code
+ */
+static efi_status_t tcg2_pcr_extend(struct udevice *dev, u32 pcr_index,
+				    struct tpml_digest_values *digest_list)
+{
+	u32 rc;
+	int i;
+
+	for (i = 0; i < digest_list->count; i++) {
+		u32 alg = digest_list->digests[i].hash_alg;
+
+		rc = tpm2_pcr_extend(dev, pcr_index, alg,
+				     (u8 *)&digest_list->digests[i].digest,
+				     alg_to_len(alg));
+		if (rc) {
+			EFI_PRINT("Failed to extend PCR\n");
+			return EFI_DEVICE_ERROR;
+		}
+	}
+
+	return EFI_SUCCESS;
+}
+
+/* tcg2_agile_log_append - Append an agile event to out eventlog
+ *
+ * @pcr_index:		PCR index
+ * @event_type:		type of event added
+ * @digest_list:	list of digest algorithms to add
+ * @size:		size of event
+ * @event:		event to add
+ *
+ * @Return: status code
+ */
+static efi_status_t tcg2_agile_log_append(u32 pcr_index, u32 event_type,
+					  struct tpml_digest_values *digest_list,
+					  u32 size, u8 event[])
+{
+	void *log = event_log.buffer + event_log.pos;
+	size_t pos;
+	int i;
+	u32 event_size;
+
+	if (event_log.get_event_called)
+		log = event_log.final_buffer + event_log.final_pos;
+
+	/*
+	 * size refers to the length of event[] only, we need to check against
+	 * the final tcg_pcr_event2 size
+	 */
+	event_size = size + tcg_event_final_size(digest_list);
+	if (event_log.pos + event_size > TPM2_EVENT_LOG_SIZE ||
+	    event_log.final_pos + event_size > TPM2_EVENT_LOG_SIZE) {
+		event_log.truncated = true;
+		return EFI_VOLUME_FULL;
+	}
+
+	put_unaligned_le32(pcr_index, log);
+	pos = offsetof(struct tcg_pcr_event2, event_type);
+	put_unaligned_le32(event_type, log + pos);
+	pos = offsetof(struct tcg_pcr_event2, digests); /* count */
+	put_unaligned_le32(digest_list->count, log + pos);
+
+	pos += offsetof(struct tpml_digest_values, digests);
+	for (i = 0; i < digest_list->count; i++) {
+		u16 hash_alg = digest_list->digests[i].hash_alg;
+		u8 *digest = (u8 *)&digest_list->digests[i].digest;
+
+		put_unaligned_le16(hash_alg, log + pos);
+		pos += offsetof(struct tpmt_ha, digest);
+		memcpy(log + pos, digest, alg_to_len(hash_alg));
+		pos += alg_to_len(hash_alg);
+	}
+
+	put_unaligned_le32(size, log + pos);
+	pos += sizeof(u32); /* tcg_pcr_event2 event_size*/
+	memcpy(log + pos, event, size);
+	pos += size;
+
+	/* make sure the calculated buffer is what we checked against */
+	if (pos != event_size)
+		return EFI_INVALID_PARAMETER;
+
+	/* if GetEventLog hasn't been called update the normal log */
+	if (!event_log.get_event_called) {
+		event_log.pos += pos;
+		event_log.last_event_size = pos;
+	} else {
+	/* if GetEventLog has been called update config table log */
+		struct efi_tcg2_final_events_table *final_event;
+
+		final_event =
+			(struct efi_tcg2_final_events_table *)(event_log.final_buffer);
+		final_event->number_of_events++;
+		event_log.final_pos += pos;
+	}
+
+	return EFI_SUCCESS;
+}
 
 /**
  * platform_get_tpm_device() - retrieve TPM device
@@ -208,7 +367,7 @@ static int tpm2_get_num_pcr(struct udevice *dev, u32 *num_pcr)
  *
  * Return: true if PCR is active
  */
-bool is_active_pcr(struct tpms_pcr_selection *selection)
+static bool is_active_pcr(struct tpms_pcr_selection *selection)
 {
 	int i;
 	/*
@@ -308,6 +467,103 @@ out:
 	return -1;
 }
 
+/**
+ * __get_active_pcr_banks() - returns the currently active PCR banks
+ *
+ * @active_pcr_banks:		pointer for receiving the bitmap of currently
+ *				active PCR banks
+ *
+ * Return:	status code
+ */
+static efi_status_t __get_active_pcr_banks(u32 *active_pcr_banks)
+{
+	struct udevice *dev;
+	u32 active, supported, pcr_banks;
+	efi_status_t ret;
+	int err;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	err = tpm2_get_pcr_info(dev, &supported, &active, &pcr_banks);
+	if (err) {
+		ret = EFI_DEVICE_ERROR;
+		goto out;
+	}
+
+	*active_pcr_banks = active;
+
+out:
+	return ret;
+}
+
+/* tcg2_create_digest - create a list of digests of the supported PCR banks
+ *			for a given memory range
+ *
+ * @input:		input memory
+ * @length:		length of buffer to calculate the digest
+ * @digest_list:	list of digests to fill in
+ *
+ * Return:		status code
+ */
+static efi_status_t tcg2_create_digest(const u8 *input, u32 length,
+				       struct tpml_digest_values *digest_list)
+{
+	sha1_context ctx;
+	sha256_context ctx_256;
+	sha512_context ctx_512;
+	u8 final[TPM2_ALG_SHA512];
+	efi_status_t ret;
+	u32 active;
+	int i;
+
+	ret = __get_active_pcr_banks(&active);
+	if (ret != EFI_SUCCESS)
+		return ret;
+
+	digest_list->count = 0;
+	for (i = 0; i < MAX_HASH_COUNT; i++) {
+		u16 hash_alg = hash_algo_list[i].hash_alg;
+
+		if (!(active & alg_to_mask(hash_alg)))
+			continue;
+		switch (hash_alg) {
+		case TPM2_ALG_SHA1:
+			sha1_starts(&ctx);
+			sha1_update(&ctx, input, length);
+			sha1_finish(&ctx, final);
+			digest_list->count++;
+			break;
+		case TPM2_ALG_SHA256:
+			sha256_starts(&ctx_256);
+			sha256_update(&ctx_256, input, length);
+			sha256_finish(&ctx_256, final);
+			digest_list->count++;
+			break;
+		case TPM2_ALG_SHA384:
+			sha384_starts(&ctx_512);
+			sha384_update(&ctx_512, input, length);
+			sha384_finish(&ctx_512, final);
+			digest_list->count++;
+			break;
+		case TPM2_ALG_SHA512:
+			sha512_starts(&ctx_512);
+			sha512_update(&ctx_512, input, length);
+			sha512_finish(&ctx_512, final);
+			digest_list->count++;
+			break;
+		default:
+			EFI_PRINT("Unsupported algorithm %x\n", hash_alg);
+			return EFI_INVALID_PARAMETER;
+		}
+		digest_list->digests[i].hash_alg = hash_alg;
+		memcpy(&digest_list->digests[i].digest, final, (u32)alg_to_len(hash_alg));
+	}
+
+	return EFI_SUCCESS;
+}
+
 /**
  * efi_tcg2_get_capability() - protocol capability information and state information
  *
@@ -427,7 +683,28 @@ efi_tcg2_get_eventlog(struct efi_tcg2_protocol *this,
 		      u64 *event_log_location, u64 *event_log_last_entry,
 		      bool *event_log_truncated)
 {
-	return EFI_UNSUPPORTED;
+	efi_status_t ret = EFI_SUCCESS;
+	struct udevice *dev;
+
+	EFI_ENTRY("%p, %u, %p, %p,  %p", this, log_format, event_log_location,
+		  event_log_last_entry, event_log_truncated);
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS) {
+		event_log_location = NULL;
+		event_log_last_entry = NULL;
+		*event_log_truncated = false;
+		ret = EFI_SUCCESS;
+		goto out;
+	}
+	*event_log_location = (uintptr_t)event_log.buffer;
+	*event_log_last_entry = (uintptr_t)(event_log.buffer + event_log.pos -
+					    event_log.last_event_size);
+	*event_log_truncated = event_log.truncated;
+	event_log.get_event_called = true;
+
+out:
+	return EFI_EXIT(ret);
 }
 
 /**
@@ -450,7 +727,76 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags,
 			       u64 data_to_hash, u64 data_to_hash_len,
 			       struct efi_tcg2_event *efi_tcg_event)
 {
-	return EFI_UNSUPPORTED;
+	struct udevice *dev;
+	efi_status_t ret;
+	u32 event_type, pcr_index, event_size;
+	struct tpml_digest_values digest_list;
+
+	EFI_ENTRY("%p, %llu, %llu, %llu, %p", this, flags, data_to_hash,
+		  data_to_hash_len, efi_tcg_event);
+
+	if (!this || !data_to_hash || !efi_tcg_event) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	if (efi_tcg_event->size < efi_tcg_event->header.header_size +
+	    sizeof(u32)) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	if (efi_tcg_event->header.pcr_index < 0 ||
+	    efi_tcg_event->header.pcr_index > TPM2_MAX_PCRS) {
+		ret = EFI_INVALID_PARAMETER;
+		goto out;
+	}
+
+	/*
+	 * if PE_COFF_IMAGE is set we need to make sure the image is not
+	 * corrupted, verify it and hash the PE/COFF image in accordance with
+	 * the  procedure  specified  in  "Calculating  the  PE  Image  Hash"
+	 * section  of the "Windows Authenticode Portable Executable Signature
+	 * Format"
+	 * Not supported for now
+	 */
+	if (flags & PE_COFF_IMAGE) {
+		ret = EFI_UNSUPPORTED;
+		goto out;
+	}
+
+	pcr_index = efi_tcg_event->header.pcr_index;
+	event_type = efi_tcg_event->header.event_type;
+
+	ret = tcg2_create_digest((u8 *)data_to_hash, data_to_hash_len,
+				 &digest_list);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = tcg2_pcr_extend(dev, pcr_index, &digest_list);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	if (flags & EFI_TCG2_EXTEND_ONLY) {
+		if (event_log.truncated)
+			ret = EFI_VOLUME_FULL;
+		goto out;
+	}
+
+	/*
+	 * The efi_tcg_event size includes the size component and the
+	 * headersize
+	 */
+	event_size = efi_tcg_event->size - sizeof(efi_tcg_event->size) -
+		efi_tcg_event->header.header_size;
+	ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
+				    event_size, efi_tcg_event->event);
+out:
+	return EFI_EXIT(ret);
 }
 
 /**
@@ -464,7 +810,7 @@ efi_tcg2_hash_log_extend_event(struct efi_tcg2_protocol *this, u64 flags,
  *
  * Return:	status code
  */
-efi_status_t EFIAPI
+static efi_status_t EFIAPI
 efi_tcg2_submit_command(struct efi_tcg2_protocol *this,
 			u32 input_param_block_size, u8 *input_param_block,
 			u32 output_param_block_size, u8 *output_param_block)
@@ -481,11 +827,16 @@ efi_tcg2_submit_command(struct efi_tcg2_protocol *this,
  *
  * Return:	status code
  */
-efi_status_t EFIAPI
+static efi_status_t EFIAPI
 efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this,
 			      u32 *active_pcr_banks)
 {
-	return EFI_UNSUPPORTED;
+	efi_status_t ret;
+
+	EFI_ENTRY("%p, %p", this, active_pcr_banks);
+	ret = __get_active_pcr_banks(active_pcr_banks);
+
+	return EFI_EXIT(ret);
 }
 
 /**
@@ -496,7 +847,7 @@ efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this,
  *
  * Return:	status code
  */
-efi_status_t EFIAPI
+static efi_status_t EFIAPI
 efi_tcg2_set_active_pcr_banks(struct efi_tcg2_protocol *this,
 			      u32 active_pcr_banks)
 {
@@ -515,7 +866,7 @@ efi_tcg2_set_active_pcr_banks(struct efi_tcg2_protocol *this,
  *
  * Return:	status code
  */
-efi_status_t EFIAPI
+static efi_status_t EFIAPI
 efi_tcg2_get_result_of_set_active_pcr_banks(struct efi_tcg2_protocol *this,
 					    u32 *operation_present, u32 *response)
 {
@@ -532,6 +883,170 @@ static const struct efi_tcg2_protocol efi_tcg2_protocol = {
 	.get_result_of_set_active_pcr_banks = efi_tcg2_get_result_of_set_active_pcr_banks,
 };
 
+/**
+ * create_specid_event() - Create the first event in the eventlog
+ *
+ * @dev:			tpm device
+ * @event_header:		Pointer to the final event header
+ * @event_size:			final spec event size
+ *
+ * Return:	status code
+ */
+static efi_status_t create_specid_event(struct udevice *dev, void *buffer,
+					size_t *event_size)
+{
+	struct tcg_efi_spec_id_event *spec_event;
+	size_t spec_event_size;
+	efi_status_t ret = EFI_DEVICE_ERROR;
+	u32 active, supported;
+	int err, i;
+
+	/*
+	 * Create Spec event. This needs to be the first event in the log
+	 * according to the TCG EFI protocol spec
+	 */
+
+	/* Setup specID event data */
+	spec_event = (struct tcg_efi_spec_id_event *)buffer;
+	memcpy(spec_event->signature, tcg_efi_spec_id_event_signature_03,
+	       sizeof(spec_event->signature));
+	put_unaligned_le32(0, &spec_event->platform_class); /* type client */
+	__put_unaligned_le(tcg_efi_spec_id_event_spec_version_minor_tpm2,
+			   &spec_event->spec_version_minor);
+	__put_unaligned_le(tcg_efi_spec_id_event_spec_version_major_tpm2,
+			   &spec_event->spec_version_major);
+	__put_unaligned_le(tcg_efi_spec_id_event_spec_version_errata_tpm2,
+			   &spec_event->spec_errata);
+	__put_unaligned_le(sizeof(efi_uintn_t) / sizeof(u32),
+			   &spec_event->uintn_size);
+
+	err = tpm2_get_pcr_info(dev, &supported, &active,
+				&spec_event->number_of_algorithms);
+	if (err)
+		goto out;
+	if (spec_event->number_of_algorithms > MAX_HASH_COUNT ||
+	    spec_event->number_of_algorithms < 1)
+		goto out;
+
+	for (i = 0; i < spec_event->number_of_algorithms; i++) {
+		u16 hash_alg = hash_algo_list[i].hash_alg;
+		u16 hash_len = hash_algo_list[i].hash_len;
+
+		if (active && alg_to_mask(hash_alg)) {
+			put_unaligned_le16(hash_alg,
+					   &spec_event->digest_sizes[i].algorithm_id);
+			put_unaligned_le32(hash_len,
+					   &spec_event->digest_sizes[i].digest_size);
+		}
+	}
+	/*
+	 * the size of the spec event and placement of vendor_info_size
+	 * depends on supported algoriths
+	 */
+	spec_event_size =
+		offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
+		spec_event->number_of_algorithms * sizeof(spec_event->digest_sizes[0]);
+	/* no vendor info for us */
+	memset(buffer + spec_event_size, 0,
+	       sizeof(spec_event->vendor_info_size));
+	spec_event_size += sizeof(spec_event->vendor_info_size);
+	*event_size = spec_event_size;
+
+	return EFI_SUCCESS;
+
+out:
+	return ret;
+}
+
+/**
+ * create_final_event() - Create the final event and install the config
+ *			defined by the TCG EFI spec
+ */
+static efi_status_t create_final_event(void)
+{
+	struct efi_tcg2_final_events_table *final_event;
+	efi_status_t ret;
+
+	/*
+	 * All events generated after the invocation of
+	 * EFI_TCG2_GET_EVENT_LOGS need to be stored in an instance of an
+	 * EFI_CONFIGURATION_TABLE
+	 */
+	ret = efi_allocate_pool(EFI_ACPI_MEMORY_NVS, TPM2_EVENT_LOG_SIZE,
+				&event_log.final_buffer);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	memset(event_log.final_buffer, 0xff, TPM2_EVENT_LOG_SIZE);
+	final_event = event_log.final_buffer;
+	final_event->number_of_events = 0;
+	final_event->version = EFI_TCG2_FINAL_EVENTS_TABLE_VERSION;
+	event_log.final_pos = sizeof(*final_event);
+	ret = efi_install_configuration_table(&efi_guid_final_events,
+					      final_event);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	return EFI_SUCCESS;
+out:
+	return ret;
+}
+
+/**
+ * efi_init_event_log() - initialize an eventlog
+ */
+static efi_status_t efi_init_event_log(void)
+{
+	/*
+	 * vendor_info_size is currently set to 0, we need to change the length
+	 * and allocate the flexible array member if this changes
+	 */
+	struct tcg_pcr_event *event_header = NULL;
+	struct udevice *dev;
+	size_t spec_event_size;
+	efi_status_t ret;
+
+	ret = platform_get_tpm2_device(&dev);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, TPM2_EVENT_LOG_SIZE,
+				(void **)&event_log.buffer);
+	if (ret != EFI_SUCCESS)
+		goto out;
+
+	/*
+	 * initialize log area as 0xff so the OS can easily figure out the
+	 * last log entry
+	 */
+	memset(event_log.buffer, 0xff, TPM2_EVENT_LOG_SIZE);
+	event_log.pos = 0;
+	event_log.last_event_size = 0;
+	event_log.get_event_called = false;
+	event_log.truncated = false;
+
+	/*
+	 * The log header is defined to be in SHA1 event log entry format.
+	 * Setup event header
+	 */
+	event_header =  (struct tcg_pcr_event *)event_log.buffer;
+	put_unaligned_le32(0, &event_header->pcr_index);
+	put_unaligned_le32(EV_NO_ACTION, &event_header->event_type);
+	memset(&event_header->digest, 0, sizeof(event_header->digest));
+	ret = create_specid_event(dev, event_log.buffer + sizeof(*event_header),
+				  &spec_event_size);
+	if (ret != EFI_SUCCESS)
+		goto out;
+	put_unaligned_le32(spec_event_size, &event_header->event_size);
+	event_log.pos = spec_event_size + sizeof(*event_header);
+	event_log.last_event_size = event_log.pos;
+
+	ret = create_final_event();
+
+out:
+	return ret;
+}
+
 /**
  * efi_tcg2_register() - register EFI_TCG2_PROTOCOL
  *
@@ -549,6 +1064,11 @@ efi_status_t efi_tcg2_register(void)
 		log_warning("Unable to find TPMv2 device\n");
 		return EFI_SUCCESS;
 	}
+
+	ret = efi_init_event_log();
+	if (ret != EFI_SUCCESS)
+		return ret;
+
 	ret = efi_add_protocol(efi_root, &efi_guid_tcg2_protocol,
 			       (void *)&efi_tcg2_protocol);
 	if (ret != EFI_SUCCESS)
-- 
2.29.2