lib/efi_loader/efi_tcg2.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Defines APIs that allow an OS to interact with UEFI firmware to query
 * information about the device.
 * https://trustedcomputinggroup.org/resource/tcg-efi-protocol-specification/
 *
 * Copyright (c) 2020, Linaro Limited
 */

#define LOG_CATEGORY LOGC_EFI

#include <dm.h>
#include <efi_loader.h>
#include <efi_variable.h>
#include <efi_tcg2.h>
#include <log.h>
#include <malloc.h>
#include <smbios.h>
#include <version_string.h>
#include <tpm_api.h>
#include <u-boot/hash-checksum.h>
#include <linux/unaligned/be_byteshift.h>
#include <linux/unaligned/le_byteshift.h>
#include <linux/unaligned/generic.h>
#include <hexdump.h>

/**
 * struct event_log_buffer - internal eventlog management structure
 *
 * @buffer:		eventlog buffer
 * @final_buffer:	finalevent config table buffer
 * @pos:		current position of 'buffer'
 * @final_pos:		current position of 'final_buffer'
 * @get_event_called:	true if GetEventLog has been invoked at least once
 * @ebs_called:		true if ExitBootServices has been invoked
 * @truncated:		true if the 'buffer' is truncated
 */
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 ebs_called;
	bool truncated;
};

static struct event_log_buffer event_log;
static bool tcg2_efi_app_invoked;
/*
 * When requesting TPM2_CAP_TPM_PROPERTIES the value is on a standard offset.
 * Since the current tpm2_get_capability() response buffers starts at
 * 'union tpmu_capabilities data' of 'struct tpms_capability_data', calculate
 * the response size and offset once for all consumers
 */
#define TPM2_RESPONSE_BUFFER_SIZE (sizeof(struct tpms_capability_data) - \
				   offsetof(struct tpms_capability_data, data))
#define properties_offset (offsetof(struct tpml_tagged_tpm_property, tpm_property) + \
			   offsetof(struct tpms_tagged_property, value))

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 variable_info {
	const u16	*name;
	bool		accept_empty;
	u32		pcr_index;
};

static struct variable_info secure_variables[] = {
	{u"SecureBoot",		true,	7},
	{u"PK",			true,	7},
	{u"KEK",		true,	7},
	{u"db",			true,	7},
	{u"dbx",		true,	7},
	{u"dbt",		false,	7},
	{u"dbr",		false,	7},
	{u"DeployedMode",	false,	1},
	{u"AuditMode",		false,	1},
};

static bool is_tcg2_protocol_installed(void)
{
	struct efi_handler *handler;
	efi_status_t ret;

	ret = efi_search_protocol(efi_root, &efi_guid_tcg2_protocol, &handler);
	return ret == EFI_SUCCESS;
}

/* tcg2_agile_log_append - Append an agile event to an 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
 * @log:		log buffer to append the event
 *
 * @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 = (void *)((uintptr_t)event_log.buffer + event_log.pos);
	u32 event_size = size + tcg2_event_get_size(digest_list);
	struct efi_tcg2_final_events_table *final_event;
	efi_status_t ret = EFI_SUCCESS;

	/* if ExitBootServices hasn't been called update the normal log */
	if (!event_log.ebs_called) {
		if (event_log.truncated ||
		    event_log.pos + event_size > CONFIG_TPM2_EVENT_LOG_SIZE) {
			event_log.truncated = true;
			return EFI_VOLUME_FULL;
		}
		tcg2_log_append(pcr_index, event_type, digest_list, size, event, log);
		event_log.pos += event_size;
		event_log.last_event_size = event_size;
	}

	if (!event_log.get_event_called)
		return ret;

	/* if GetEventLog has been called update FinalEventLog as well */
	if (event_log.final_pos + event_size > CONFIG_TPM2_EVENT_LOG_SIZE)
		return EFI_VOLUME_FULL;

	log = (void *)((uintptr_t)event_log.final_buffer + event_log.final_pos);
	tcg2_log_append(pcr_index, event_type, digest_list, size, event, log);

	final_event = event_log.final_buffer;
	final_event->number_of_events++;
	event_log.final_pos += event_size;

	return ret;
}

/**
 * tpm2_get_max_command_size() - get the supported max command size
 *
 * @dev:		TPM device
 * @max_command_size:	output buffer for the size
 *
 * Return: 0 on success, -1 on error
 */
static int tpm2_get_max_command_size(struct udevice *dev, u16 *max_command_size)
{
	u8 response[TPM2_RESPONSE_BUFFER_SIZE];
	u32 ret;

	memset(response, 0, sizeof(response));
	ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
				  TPM2_PT_MAX_COMMAND_SIZE, response, 1);
	if (ret)
		return -1;

	*max_command_size = (uint16_t)get_unaligned_be32(response +
							 properties_offset);

	return 0;
}

/**
 * tpm2_get_max_response_size() - get the supported max response size
 *
 * @dev:		TPM device
 * @max_response_size:	output buffer for the size
 *
 * Return: 0 on success, -1 on error
 */
static int tpm2_get_max_response_size(struct udevice *dev,
				      u16 *max_response_size)
{
	u8 response[TPM2_RESPONSE_BUFFER_SIZE];
	u32 ret;

	memset(response, 0, sizeof(response));
	ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
				  TPM2_PT_MAX_RESPONSE_SIZE, response, 1);
	if (ret)
		return -1;

	*max_response_size = (uint16_t)get_unaligned_be32(response +
							  properties_offset);

	return 0;
}

/**
 * tpm2_get_manufacturer_id() - get the manufacturer ID
 *
 * @dev:		TPM device
 * @manufacturer_id:	output buffer for the id
 *
 * Return: 0 on success, -1 on error
 */
static int tpm2_get_manufacturer_id(struct udevice *dev, u32 *manufacturer_id)
{
	u8 response[TPM2_RESPONSE_BUFFER_SIZE];
	u32 ret;

	memset(response, 0, sizeof(response));
	ret = tpm2_get_capability(dev, TPM2_CAP_TPM_PROPERTIES,
				  TPM2_PT_MANUFACTURER, response, 1);
	if (ret)
		return -1;

	*manufacturer_id = get_unaligned_be32(response + properties_offset);

	return 0;
}

/**
 * efi_tcg2_get_capability() - protocol capability information and state information
 *
 * @this:		TCG2 protocol instance
 * @capability:		caller allocated memory with size field to the size of
 *			the structure allocated

 * Return:	status code
 */
static efi_status_t EFIAPI
efi_tcg2_get_capability(struct efi_tcg2_protocol *this,
			struct efi_tcg2_boot_service_capability *capability)
{
	struct udevice *dev;
	efi_status_t efi_ret;
	int ret;

	EFI_ENTRY("%p, %p", this, capability);

	if (!this || !capability) {
		efi_ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	if (capability->size < BOOT_SERVICE_CAPABILITY_MIN) {
		capability->size = BOOT_SERVICE_CAPABILITY_MIN;
		efi_ret = EFI_BUFFER_TOO_SMALL;
		goto out;
	}

	if (capability->size < sizeof(*capability)) {
		capability->size = sizeof(*capability);
		efi_ret = EFI_BUFFER_TOO_SMALL;
		goto out;
	}

	capability->structure_version.major = 1;
	capability->structure_version.minor = 1;
	capability->protocol_version.major = 1;
	capability->protocol_version.minor = 1;

	ret = tcg2_platform_get_tpm2(&dev);
	if (ret) {
		capability->supported_event_logs = 0;
		capability->hash_algorithm_bitmap = 0;
		capability->tpm_present_flag = false;
		capability->max_command_size = 0;
		capability->max_response_size = 0;
		capability->manufacturer_id = 0;
		capability->number_of_pcr_banks = 0;
		capability->active_pcr_banks = 0;

		efi_ret = EFI_SUCCESS;
		goto out;
	}

	/* We only allow a TPMv2 device to register the EFI protocol */
	capability->supported_event_logs = TCG2_EVENT_LOG_FORMAT_TCG_2;

	capability->tpm_present_flag = true;

	/* Supported and active PCRs */
	capability->hash_algorithm_bitmap = 0;
	capability->active_pcr_banks = 0;
	ret = tcg2_get_pcr_info(dev, &capability->hash_algorithm_bitmap,
				&capability->active_pcr_banks,
				&capability->number_of_pcr_banks);
	if (ret) {
		efi_ret = EFI_DEVICE_ERROR;
		goto out;
	}

	/* Max command size */
	ret = tpm2_get_max_command_size(dev, &capability->max_command_size);
	if (ret) {
		efi_ret = EFI_DEVICE_ERROR;
		goto out;
	}

	/* Max response size */
	ret = tpm2_get_max_response_size(dev, &capability->max_response_size);
	if (ret) {
		efi_ret = EFI_DEVICE_ERROR;
		goto out;
	}

	/* Manufacturer ID */
	ret = tpm2_get_manufacturer_id(dev, &capability->manufacturer_id);
	if (ret) {
		efi_ret = EFI_DEVICE_ERROR;
		goto out;
	}

	return EFI_EXIT(EFI_SUCCESS);
out:
	return EFI_EXIT(efi_ret);
}

/**
 * efi_tcg2_get_eventlog() -	retrieve the the address of an event log and its
 *				last entry
 *
 * @this:			TCG2 protocol instance
 * @log_format:			type of event log format
 * @event_log_location:		pointer to the memory address of the event log
 * @event_log_last_entry:	pointer to the address of the start of the last
 *				entry in the event log in memory, if log contains
 *				more than 1 entry
 * @event_log_truncated:	set to true, if the Event Log is missing at i
 *				least one entry
 *
 * Return:	status code
 */
static efi_status_t EFIAPI
efi_tcg2_get_eventlog(struct efi_tcg2_protocol *this,
		      efi_tcg_event_log_format log_format,
		      u64 *event_log_location, u64 *event_log_last_entry,
		      bool *event_log_truncated)
{
	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);

	if (!this || !event_log_location || !event_log_last_entry ||
	    !event_log_truncated) {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	/* Only support TPMV2 */
	if (log_format != TCG2_EVENT_LOG_FORMAT_TCG_2) {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	if (tcg2_platform_get_tpm2(&dev)) {
		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);
}

/**
 * tcg2_hash_pe_image() - calculate PE/COFF image hash
 *
 * @efi:		pointer to the EFI binary
 * @efi_size:		size of @efi binary
 * @digest_list:	list of digest algorithms to extend
 *
 * Return:	status code
 */
static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
				       struct tpml_digest_values *digest_list)
{
	WIN_CERTIFICATE *wincerts = NULL;
	size_t wincerts_len;
	struct efi_image_regions *regs = NULL;
	void *new_efi = NULL;
	u8 hash[TPM2_SHA512_DIGEST_SIZE];
	struct udevice *dev;
	efi_status_t ret = EFI_SUCCESS;
	u32 active;
	int i;

	new_efi = efi_prepare_aligned_image(efi, &efi_size);
	if (!new_efi)
		return EFI_OUT_OF_RESOURCES;

	if (!efi_image_parse(new_efi, efi_size, &regs, &wincerts,
			     &wincerts_len)) {
		log_err("Parsing PE executable image failed\n");
		ret = EFI_UNSUPPORTED;
		goto out;
	}

	if (tcg2_platform_get_tpm2(&dev)) {
		ret = EFI_DEVICE_ERROR;
		goto out;
	}

	if (tcg2_get_active_pcr_banks(dev, &active)) {
		ret = EFI_DEVICE_ERROR;
		goto out;
	}

	digest_list->count = 0;
	for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
		u16 hash_alg = hash_algo_list[i].hash_alg;

		if (!(active & hash_algo_list[i].hash_mask))
			continue;
		switch (hash_alg) {
		case TPM2_ALG_SHA1:
			hash_calculate("sha1", regs->reg, regs->num, hash);
			break;
		case TPM2_ALG_SHA256:
			hash_calculate("sha256", regs->reg, regs->num, hash);
			break;
		case TPM2_ALG_SHA384:
			hash_calculate("sha384", regs->reg, regs->num, hash);
			break;
		case TPM2_ALG_SHA512:
			hash_calculate("sha512", regs->reg, regs->num, hash);
			break;
		default:
			continue;
		}
		digest_list->digests[digest_list->count].hash_alg = hash_alg;
		memcpy(&digest_list->digests[digest_list->count].digest, hash,
		       (u32)tpm2_algorithm_to_len(hash_alg));
		digest_list->count++;
	}

out:
	if (new_efi != efi)
		free(new_efi);
	free(regs);

	return ret;
}

/**
 * tcg2_measure_pe_image() - measure PE/COFF image
 *
 * @efi:		pointer to the EFI binary
 * @efi_size:		size of @efi binary
 * @handle:		loaded image handle
 * @loaded_image:	loaded image protocol
 *
 * Return:	status code
 */
efi_status_t tcg2_measure_pe_image(void *efi, u64 efi_size,
				   struct efi_loaded_image_obj *handle,
				   struct efi_loaded_image *loaded_image)
{
	struct tpml_digest_values digest_list;
	efi_status_t ret;
	struct udevice *dev;
	u32 pcr_index, event_type, event_size;
	struct uefi_image_load_event *image_load_event;
	struct efi_device_path *device_path;
	u32 device_path_length;
	IMAGE_DOS_HEADER *dos;
	IMAGE_NT_HEADERS32 *nt;
	struct efi_handler *handler;
	int rc;

	if (!is_tcg2_protocol_installed())
		return EFI_SUCCESS;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_SECURITY_VIOLATION;

	switch (handle->image_type) {
	case IMAGE_SUBSYSTEM_EFI_APPLICATION:
		pcr_index = 4;
		event_type = EV_EFI_BOOT_SERVICES_APPLICATION;
		break;
	case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
		pcr_index = 2;
		event_type = EV_EFI_BOOT_SERVICES_DRIVER;
		break;
	case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
		pcr_index = 2;
		event_type = EV_EFI_RUNTIME_SERVICES_DRIVER;
		break;
	default:
		return EFI_UNSUPPORTED;
	}

	ret = tcg2_hash_pe_image(efi, efi_size, &digest_list);
	if (ret != EFI_SUCCESS)
		return ret;

	rc = tcg2_pcr_extend(dev, pcr_index, &digest_list);
	if (rc)
		return EFI_DEVICE_ERROR;

	ret = efi_search_protocol(&handle->header,
				  &efi_guid_loaded_image_device_path, &handler);
	if (ret != EFI_SUCCESS)
		return ret;

	device_path = handler->protocol_interface;
	device_path_length = efi_dp_size(device_path);
	if (device_path_length > 0) {
		/* add end node size */
		device_path_length += sizeof(struct efi_device_path);
	}
	event_size = sizeof(struct uefi_image_load_event) + device_path_length;
	image_load_event = calloc(1, event_size);
	if (!image_load_event)
		return EFI_OUT_OF_RESOURCES;

	image_load_event->image_location_in_memory = (uintptr_t)efi;
	image_load_event->image_length_in_memory = efi_size;
	image_load_event->length_of_device_path = device_path_length;

	dos = (IMAGE_DOS_HEADER *)efi;
	nt = (IMAGE_NT_HEADERS32 *)(efi + dos->e_lfanew);
	if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
		IMAGE_NT_HEADERS64 *nt64 = (IMAGE_NT_HEADERS64 *)nt;

		image_load_event->image_link_time_address =
				nt64->OptionalHeader.ImageBase;
	} else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
		image_load_event->image_link_time_address =
				nt->OptionalHeader.ImageBase;
	} else {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	/* device_path_length might be zero */
	memcpy(image_load_event->device_path, device_path, device_path_length);

	ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
				    event_size, (u8 *)image_load_event);

out:
	free(image_load_event);

	return ret;
}

/**
 * efi_tcg2_hash_log_extend_event() - extend and optionally log events
 *
 * @this:			TCG2 protocol instance
 * @flags:			bitmap providing additional information on the
 *				operation
 * @data_to_hash:		physical address of the start of the data buffer
 *				to be hashed
 * @data_to_hash_len:		the length in bytes of the buffer referenced by
 *				data_to_hash
 * @efi_tcg_event:		pointer to data buffer containing information
 *				about the event
 *
 * Return:	status code
 */
static efi_status_t EFIAPI
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)
{
	struct udevice *dev;
	efi_status_t ret = EFI_SUCCESS;
	u32 event_type, pcr_index, event_size;
	struct tpml_digest_values digest_list;
	int rc = 0;

	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;
	}

	if (tcg2_platform_get_tpm2(&dev)) {
		ret = EFI_DEVICE_ERROR;
		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 > EFI_TCG2_MAX_PCR_INDEX) {
		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"
	 */
	if (flags & PE_COFF_IMAGE) {
		ret = efi_check_pe((void *)(uintptr_t)data_to_hash,
				   data_to_hash_len, NULL);
		if (ret != EFI_SUCCESS) {
			ret = EFI_UNSUPPORTED;
			goto out;
		}
		ret = tcg2_hash_pe_image((void *)(uintptr_t)data_to_hash,
					 data_to_hash_len, &digest_list);
	} else {
		rc = tcg2_create_digest(dev, (u8 *)(uintptr_t)data_to_hash,
					data_to_hash_len, &digest_list);
		if (rc)
			ret = EFI_DEVICE_ERROR;
	}

	if (ret != EFI_SUCCESS)
		goto out;

	pcr_index = efi_tcg_event->header.pcr_index;
	event_type = efi_tcg_event->header.event_type;

	rc = tcg2_pcr_extend(dev, pcr_index, &digest_list);
	if (rc) {
		ret = EFI_DEVICE_ERROR;
		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);
}

/**
 * efi_tcg2_submit_command() - Send command to the TPM
 *
 * @this:			TCG2 protocol instance
 * @input_param_block_size:	size of the TPM input parameter block
 * @input_param_block:		pointer to the TPM input parameter block
 * @output_param_block_size:	size of the TPM output parameter block
 * @output_param_block:		pointer to the TPM output parameter block
 *
 * Return:	status code
 */
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)
{
	struct udevice *dev;
	efi_status_t ret = EFI_SUCCESS;
	u32 rc;
	size_t resp_buf_size = output_param_block_size;

	EFI_ENTRY("%p, %u, %p, %u, %p", this, input_param_block_size,
		  input_param_block, output_param_block_size, output_param_block);

	if (!this || !input_param_block || !input_param_block_size) {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	if (tcg2_platform_get_tpm2(&dev)) {
		ret = EFI_DEVICE_ERROR;
		goto out;
	}

	rc = tpm2_submit_command(dev, input_param_block,
				 output_param_block, &resp_buf_size);
	if (rc) {
		ret = (rc == -ENOSPC) ? EFI_OUT_OF_RESOURCES : EFI_DEVICE_ERROR;

		goto out;
	}

out:
	return EFI_EXIT(ret);
}

/**
 * efi_tcg2_get_active_pcr_banks() - returns the currently active PCR banks
 *
 * @this:			TCG2 protocol instance
 * @active_pcr_banks:		pointer for receiving the bitmap of currently
 *				active PCR banks
 *
 * Return:	status code
 */
static efi_status_t EFIAPI
efi_tcg2_get_active_pcr_banks(struct efi_tcg2_protocol *this,
			      u32 *active_pcr_banks)
{
	struct udevice *dev;
	efi_status_t ret = EFI_INVALID_PARAMETER;

	EFI_ENTRY("%p, %p", this, active_pcr_banks);

	if (!this || !active_pcr_banks)
		goto out;

	if (tcg2_platform_get_tpm2(&dev))
		goto out;

	/*
	 * EFI_INVALID_PARAMETER does not convey the problem type.
	 * but that's what currently the spec specifies.
	 * EFI_DEVICE_ERROR would be better
	 */
	if (tcg2_get_active_pcr_banks(dev, active_pcr_banks))
		goto out;

	ret = EFI_SUCCESS;

out:
	return EFI_EXIT(ret);
}

/**
 * efi_tcg2_set_active_pcr_banks() - sets the currently active PCR banks
 *
 * @this:			TCG2 protocol instance
 * @active_pcr_banks:		bitmap of the requested active PCR banks
 *
 * Return:	status code
 */
static efi_status_t EFIAPI
efi_tcg2_set_active_pcr_banks(__maybe_unused struct efi_tcg2_protocol *this,
			      u32 __maybe_unused active_pcr_banks)
{
	return EFI_UNSUPPORTED;
}

/**
 * efi_tcg2_get_result_of_set_active_pcr_banks() - retrieve result for previous
 *						   set_active_pcr_banks()
 *
 * @this:			TCG2 protocol instance
 * @operation_present:		non-zero value to indicate a
 *				set_active_pcr_banks operation was
 *				invoked during last boot
 * @response:			result value could be returned
 *
 * Return:	status code
 */
static efi_status_t EFIAPI
efi_tcg2_get_result_of_set_active_pcr_banks(__maybe_unused struct efi_tcg2_protocol *this,
					    u32 __maybe_unused *operation_present,
					    u32 __maybe_unused *response)
{
	return EFI_UNSUPPORTED;
}

static const struct efi_tcg2_protocol efi_tcg2_protocol = {
	.get_capability = efi_tcg2_get_capability,
	.get_eventlog = efi_tcg2_get_eventlog,
	.hash_log_extend_event = efi_tcg2_hash_log_extend_event,
	.submit_command = efi_tcg2_submit_command,
	.get_active_pcr_banks = efi_tcg2_get_active_pcr_banks,
	.set_active_pcr_banks = efi_tcg2_set_active_pcr_banks,
	.get_result_of_set_active_pcr_banks = efi_tcg2_get_result_of_set_active_pcr_banks,
};

/**
 * tcg2_uninit - remove the final event table and free efi memory on failures
 */
static void tcg2_uninit(void)
{
	efi_status_t ret;

	ret = efi_install_configuration_table(&efi_guid_final_events, NULL);
	if (ret != EFI_SUCCESS && ret != EFI_NOT_FOUND)
		log_err("Failed to delete final events config table\n");

	efi_free_pool(event_log.buffer);
	event_log.buffer = NULL;
	efi_free_pool(event_log.final_buffer);
	event_log.final_buffer = NULL;

	if (!is_tcg2_protocol_installed())
		return;

	ret = efi_uninstall_multiple_protocol_interfaces(efi_root, &efi_guid_tcg2_protocol,
							 &efi_tcg2_protocol, NULL);
	if (ret != EFI_SUCCESS)
		log_err("Failed to remove EFI TCG2 protocol\n");
}

/**
 * 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, CONFIG_TPM2_EVENT_LOG_SIZE,
				&event_log.final_buffer);
	if (ret != EFI_SUCCESS)
		goto out;

	memset(event_log.final_buffer, 0xff, CONFIG_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) {
		efi_free_pool(event_log.final_buffer);
		event_log.final_buffer = NULL;
	}

out:
	return ret;
}

/**
 * measure_event() - common function to add event log and extend PCR
 *
 * @dev:		TPM device
 * @pcr_index:		PCR index
 * @event_type:		type of event added
 * @size:		event size
 * @event:		event data
 *
 * Return:	status code
 */
static efi_status_t measure_event(struct udevice *dev, u32 pcr_index,
				  u32 event_type, u32 size, u8 event[])
{
	struct tpml_digest_values digest_list;
	efi_status_t ret = EFI_DEVICE_ERROR;
	int rc;

	rc = tcg2_create_digest(dev, event, size, &digest_list);
	if (rc)
		goto out;

	rc = tcg2_pcr_extend(dev, pcr_index, &digest_list);
	if (rc)
		goto out;

	ret = tcg2_agile_log_append(pcr_index, event_type, &digest_list,
				    size, event);

out:
	return ret;
}

/**
 * efi_append_scrtm_version - Append an S-CRTM EV_S_CRTM_VERSION event on the
 *			      eventlog and extend the PCRs
 *
 * @dev:	TPM device
 *
 * @Return:	status code
 */
static efi_status_t efi_append_scrtm_version(struct udevice *dev)
{
	efi_status_t ret;

	ret = measure_event(dev, 0, EV_S_CRTM_VERSION,
			    strlen(version_string) + 1, (u8 *)version_string);

	return ret;
}

/**
 * efi_init_event_log() - initialize an eventlog
 *
 * Return:		status code
 */
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 tcg2_event_log elog;
	struct udevice *dev;
	efi_status_t ret;
	int rc;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_DEVICE_ERROR;

	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA,
				CONFIG_TPM2_EVENT_LOG_SIZE,
				(void **)&event_log.buffer);
	if (ret != EFI_SUCCESS)
		return ret;

	/*
	 * initialize log area as 0xff so the OS can easily figure out the
	 * last log entry
	 */
	memset(event_log.buffer, 0xff, CONFIG_TPM2_EVENT_LOG_SIZE);

	/*
	 * The log header is defined to be in SHA1 event log entry format.
	 * Setup event header
	 */
	event_log.pos = 0;
	event_log.last_event_size = 0;
	event_log.get_event_called = false;
	event_log.ebs_called = false;
	event_log.truncated = false;

	/*
	 * Check if earlier firmware have passed any eventlog. Different
	 * platforms can use different ways to do so.
	 */
	elog.log = event_log.buffer;
	elog.log_size = CONFIG_TPM2_EVENT_LOG_SIZE;
	rc = tcg2_log_prepare_buffer(dev, &elog, false);
	if (rc) {
		ret = (rc == -ENOBUFS) ? EFI_BUFFER_TOO_SMALL : EFI_DEVICE_ERROR;
		goto free_pool;
	}

	event_log.pos = elog.log_position;

	/*
	 * Add SCRTM version to the log if previous firmmware
	 * doesn't pass an eventlog.
	 */
	if (!elog.found) {
		ret = efi_append_scrtm_version(dev);
		if (ret != EFI_SUCCESS)
			goto free_pool;
	}

	ret = create_final_event();
	if (ret != EFI_SUCCESS)
		goto free_pool;

	return ret;

free_pool:
	efi_free_pool(event_log.buffer);
	event_log.buffer = NULL;
	return ret;
}

/**
 * tcg2_measure_variable() - add variable event log and extend PCR
 *
 * @dev:		TPM device
 * @pcr_index:		PCR index
 * @event_type:		type of event added
 * @var_name:		variable name
 * @guid:		guid
 * @data_size:		variable data size
 * @data:		variable data
 *
 * Return:	status code
 */
static efi_status_t tcg2_measure_variable(struct udevice *dev, u32 pcr_index,
					  u32 event_type, const u16 *var_name,
					  const efi_guid_t *guid,
					  efi_uintn_t data_size, u8 *data)
{
	u32 event_size;
	efi_status_t ret;
	struct efi_tcg2_uefi_variable_data *event;

	event_size = sizeof(event->variable_name) +
		     sizeof(event->unicode_name_length) +
		     sizeof(event->variable_data_length) +
		     (u16_strlen(var_name) * sizeof(u16)) + data_size;
	event = malloc(event_size);
	if (!event)
		return EFI_OUT_OF_RESOURCES;

	guidcpy(&event->variable_name, guid);
	event->unicode_name_length = u16_strlen(var_name);
	event->variable_data_length = data_size;
	memcpy(event->unicode_name, var_name,
	       (event->unicode_name_length * sizeof(u16)));
	if (data) {
		memcpy((u16 *)event->unicode_name + event->unicode_name_length,
		       data, data_size);
	}
	ret = measure_event(dev, pcr_index, event_type, event_size,
			    (u8 *)event);
	free(event);
	return ret;
}

/**
 * tcg2_measure_boot_variable() - measure boot variables
 *
 * @dev:	TPM device
 *
 * Return:	status code
 */
static efi_status_t tcg2_measure_boot_variable(struct udevice *dev)
{
	u16 *boot_order;
	u16 *boot_index;
	u16 var_name[] = u"BootOrder";
	u16 boot_name[] = u"Boot####";
	u8 *bootvar;
	efi_uintn_t var_data_size;
	u32 count, i;
	efi_status_t ret;

	boot_order = efi_get_var(var_name, &efi_global_variable_guid,
				 &var_data_size);
	if (!boot_order) {
		/* If "BootOrder" is not defined, skip the boot variable measurement */
		return EFI_SUCCESS;
	}

	ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2, var_name,
				    &efi_global_variable_guid, var_data_size,
				    (u8 *)boot_order);
	if (ret != EFI_SUCCESS)
		goto error;

	count = var_data_size / sizeof(*boot_order);
	boot_index = boot_order;
	for (i = 0; i < count; i++) {
		efi_create_indexed_name(boot_name, sizeof(boot_name),
					"Boot", *boot_index++);

		bootvar = efi_get_var(boot_name, &efi_global_variable_guid,
				      &var_data_size);

		if (!bootvar) {
			log_debug("%ls not found\n", boot_name);
			continue;
		}

		ret = tcg2_measure_variable(dev, 1, EV_EFI_VARIABLE_BOOT2,
					    boot_name,
					    &efi_global_variable_guid,
					    var_data_size, bootvar);
		free(bootvar);
		if (ret != EFI_SUCCESS)
			goto error;
	}

error:
	free(boot_order);
	return ret;
}

/**
 * tcg2_measure_smbios() - measure smbios table
 *
 * @dev:	TPM device
 * @entry:	pointer to the smbios_entry structure
 *
 * Return:	status code
 */
static efi_status_t
tcg2_measure_smbios(struct udevice *dev,
		    const struct smbios3_entry *entry)
{
	efi_status_t ret;
	struct smbios_header *smbios_copy;
	struct smbios_handoff_table_pointers2 *event = NULL;
	u32 event_size;
	const char smbios3_anchor[] = "_SM3_";

	/* We only support SMBIOS 3.0 Entry Point structure */
	if (memcmp(entry->anchor, smbios3_anchor, sizeof(smbios3_anchor) - 1))
		return EFI_UNSUPPORTED;

	/*
	 * TCG PC Client PFP Spec says
	 * "SMBIOS structures that contain static configuration information
	 * (e.g. Platform Manufacturer Enterprise Number assigned by IANA,
	 * platform model number, Vendor and Device IDs for each SMBIOS table)
	 * that is relevant to the security of the platform MUST be measured".
	 * Device dependent parameters such as serial number are cleared to
	 * zero or spaces for the measurement.
	 */
	event_size = sizeof(struct smbios_handoff_table_pointers2) +
		     FIELD_SIZEOF(struct efi_configuration_table, guid) +
		     entry->table_maximum_size;
	event = calloc(1, event_size);
	if (!event) {
		ret = EFI_OUT_OF_RESOURCES;
		goto out;
	}

	event->table_description_size = sizeof(SMBIOS_HANDOFF_TABLE_DESC);
	memcpy(event->table_description, SMBIOS_HANDOFF_TABLE_DESC,
	       sizeof(SMBIOS_HANDOFF_TABLE_DESC));
	put_unaligned_le64(1, &event->number_of_tables);
	guidcpy(&event->table_entry[0].guid, &smbios3_guid);
	smbios_copy = (struct smbios_header *)((uintptr_t)&event->table_entry[0].table);
	memcpy(&event->table_entry[0].table,
	       (void *)((uintptr_t)entry->struct_table_address),
	       entry->table_maximum_size);

	smbios_prepare_measurement(entry, smbios_copy);

	ret = measure_event(dev, 1, EV_EFI_HANDOFF_TABLES2, event_size,
			    (u8 *)event);
	if (ret != EFI_SUCCESS)
		goto out;

out:
	free(event);

	return ret;
}

/**
 * tcg2_measure_gpt_table() - measure gpt table
 *
 * @dev:		TPM device
 * @loaded_image:	handle to the loaded image
 *
 * Return:	status code
 */
static efi_status_t
tcg2_measure_gpt_data(struct udevice *dev,
		      struct efi_loaded_image_obj *loaded_image)
{
	efi_status_t ret;
	efi_handle_t handle;
	struct efi_handler *dp_handler, *io_handler;
	struct efi_device_path *orig_device_path;
	struct efi_device_path *device_path;
	struct efi_device_path *dp;
	struct efi_block_io *block_io;
	struct efi_gpt_data *event = NULL;
	efi_guid_t null_guid = NULL_GUID;
	gpt_header *gpt_h;
	gpt_entry *entry = NULL;
	gpt_entry *gpt_e;
	u32 num_of_valid_entry = 0;
	u32 event_size;
	u32 i;
	u32 total_gpt_entry_size;

	ret = efi_search_protocol(&loaded_image->header,
				  &efi_guid_loaded_image_device_path,
				  &dp_handler);
	if (ret != EFI_SUCCESS)
		return ret;

	orig_device_path = dp_handler->protocol_interface;
	if (!orig_device_path) /* no device path, skip GPT measurement */
		return EFI_SUCCESS;

	device_path = efi_dp_dup(orig_device_path);
	if (!device_path)
		return EFI_OUT_OF_RESOURCES;

	dp = search_gpt_dp_node(device_path);
	if (!dp) {
		/* no GPT device path node found, skip GPT measurement */
		ret = EFI_SUCCESS;
		goto out1;
	}

	/* read GPT header */
	dp->type = DEVICE_PATH_TYPE_END;
	dp->sub_type = DEVICE_PATH_SUB_TYPE_END;
	dp = device_path;
	ret = EFI_CALL(systab.boottime->locate_device_path(&efi_block_io_guid,
							   &dp, &handle));
	if (ret != EFI_SUCCESS)
		goto out1;

	ret = efi_search_protocol(handle, &efi_block_io_guid, &io_handler);
	if (ret != EFI_SUCCESS)
		goto out1;
	block_io = io_handler->protocol_interface;

	gpt_h = memalign(block_io->media->io_align, block_io->media->block_size);
	if (!gpt_h) {
		ret = EFI_OUT_OF_RESOURCES;
		goto out2;
	}

	ret = block_io->read_blocks(block_io, block_io->media->media_id, 1,
				    block_io->media->block_size, gpt_h);
	if (ret != EFI_SUCCESS)
		goto out2;

	/* read GPT entry */
	total_gpt_entry_size = gpt_h->num_partition_entries *
			       gpt_h->sizeof_partition_entry;
	entry = memalign(block_io->media->io_align, total_gpt_entry_size);
	if (!entry) {
		ret = EFI_OUT_OF_RESOURCES;
		goto out2;
	}

	ret = block_io->read_blocks(block_io, block_io->media->media_id,
				    gpt_h->partition_entry_lba,
				    total_gpt_entry_size, entry);
	if (ret != EFI_SUCCESS)
		goto out2;

	/* count valid GPT entry */
	gpt_e = entry;
	for (i = 0; i < gpt_h->num_partition_entries; i++) {
		if (guidcmp(&null_guid, &gpt_e->partition_type_guid))
			num_of_valid_entry++;

		gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
	}

	/* prepare event data for measurement */
	event_size = sizeof(struct efi_gpt_data) +
		(num_of_valid_entry * gpt_h->sizeof_partition_entry);
	event = calloc(1, event_size);
	if (!event) {
		ret = EFI_OUT_OF_RESOURCES;
		goto out2;
	}
	memcpy(event, gpt_h, sizeof(gpt_header));
	put_unaligned_le64(num_of_valid_entry, &event->number_of_partitions);

	/* copy valid GPT entry */
	gpt_e = entry;
	num_of_valid_entry = 0;
	for (i = 0; i < gpt_h->num_partition_entries; i++) {
		if (guidcmp(&null_guid, &gpt_e->partition_type_guid)) {
			memcpy((u8 *)event->partitions +
			       (num_of_valid_entry * gpt_h->sizeof_partition_entry),
			       gpt_e, gpt_h->sizeof_partition_entry);
			num_of_valid_entry++;
		}

		gpt_e = (gpt_entry *)((u8 *)gpt_e + gpt_h->sizeof_partition_entry);
	}

	ret = measure_event(dev, 5, EV_EFI_GPT_EVENT, event_size, (u8 *)event);

out2:
	free(gpt_h);
	free(entry);
	free(event);
out1:
	efi_free_pool(device_path);

	return ret;
}

/* Return the byte size of reserved map area in DTB or -1 upon error */
static ssize_t size_of_rsvmap(void *dtb)
{
	struct fdt_reserve_entry e;
	ssize_t size_max;
	ssize_t size;
	u8 *rsvmap_base;

	rsvmap_base = (u8 *)dtb + fdt_off_mem_rsvmap(dtb);
	size_max = fdt_totalsize(dtb) - fdt_off_mem_rsvmap(dtb);
	size = 0;

	do {
		memcpy(&e, rsvmap_base + size, sizeof(e));
		size += sizeof(e);
		if (size > size_max)
			return -1;
	} while (e.size);

	return size;
}

/**
 * efi_tcg2_measure_dtb() - measure DTB passed to the OS
 *
 * @dtb: pointer to the device tree blob
 *
 * Return:	status code
 */
efi_status_t efi_tcg2_measure_dtb(void *dtb)
{
	struct uefi_platform_firmware_blob2 *blob;
	struct fdt_header *header;
	sha256_context hash_ctx;
	struct udevice *dev;
	ssize_t rsvmap_size;
	efi_status_t ret;
	u32 event_size;

	if (!is_tcg2_protocol_installed())
		return EFI_SUCCESS;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_SECURITY_VIOLATION;

	rsvmap_size = size_of_rsvmap(dtb);
	if (rsvmap_size < 0)
		return EFI_SECURITY_VIOLATION;

	event_size = sizeof(*blob) + sizeof(EFI_DTB_EVENT_STRING) + SHA256_SUM_LEN;
	blob = calloc(1, event_size);
	if (!blob)
		return EFI_OUT_OF_RESOURCES;

	blob->blob_description_size = sizeof(EFI_DTB_EVENT_STRING);
	memcpy(blob->data, EFI_DTB_EVENT_STRING, blob->blob_description_size);

	/* Measure populated areas of the DTB */
	header = dtb;
	sha256_starts(&hash_ctx);
	sha256_update(&hash_ctx, (u8 *)header, sizeof(struct fdt_header));
	sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_dt_struct(dtb), fdt_size_dt_strings(dtb));
	sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_dt_strings(dtb), fdt_size_dt_struct(dtb));
	sha256_update(&hash_ctx, (u8 *)dtb + fdt_off_mem_rsvmap(dtb), rsvmap_size);
	sha256_finish(&hash_ctx, blob->data + blob->blob_description_size);

	ret = measure_event(dev, 1, EV_POST_CODE, event_size, (u8 *)blob);

	free(blob);
	return ret;
}

/**
 * efi_tcg2_measure_efi_app_invocation() - measure efi app invocation
 *
 * Return:	status code
 */
efi_status_t efi_tcg2_measure_efi_app_invocation(struct efi_loaded_image_obj *handle)
{
	efi_status_t ret;
	u32 pcr_index;
	struct udevice *dev;
	u32 event = 0;
	struct smbios3_entry *entry;

	if (!is_tcg2_protocol_installed())
		return EFI_SUCCESS;

	if (tcg2_efi_app_invoked)
		return EFI_SUCCESS;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_SECURITY_VIOLATION;

	ret = tcg2_measure_boot_variable(dev);
	if (ret != EFI_SUCCESS)
		goto out;

	ret = measure_event(dev, 4, EV_EFI_ACTION,
			    strlen(EFI_CALLING_EFI_APPLICATION),
			    (u8 *)EFI_CALLING_EFI_APPLICATION);
	if (ret != EFI_SUCCESS)
		goto out;

	entry = efi_get_configuration_table(&smbios3_guid);
	if (entry) {
		ret = tcg2_measure_smbios(dev, entry);
		if (ret != EFI_SUCCESS)
			goto out;
	}

	ret = tcg2_measure_gpt_data(dev, handle);
	if (ret != EFI_SUCCESS)
		goto out;

	for (pcr_index = 0; pcr_index <= 7; pcr_index++) {
		ret = measure_event(dev, pcr_index, EV_SEPARATOR,
				    sizeof(event), (u8 *)&event);
		if (ret != EFI_SUCCESS)
			goto out;
	}

	tcg2_efi_app_invoked = true;
out:
	return ret;
}

/**
 * efi_tcg2_measure_efi_app_exit() - measure efi app exit
 *
 * Return:	status code
 */
efi_status_t efi_tcg2_measure_efi_app_exit(void)
{
	efi_status_t ret;
	struct udevice *dev;

	if (!is_tcg2_protocol_installed())
		return EFI_SUCCESS;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_SECURITY_VIOLATION;

	ret = measure_event(dev, 4, EV_EFI_ACTION,
			    strlen(EFI_RETURNING_FROM_EFI_APPLICATION),
			    (u8 *)EFI_RETURNING_FROM_EFI_APPLICATION);
	return ret;
}

/**
 * efi_tcg2_notify_exit_boot_services() - ExitBootService callback
 *
 * @event:	callback event
 * @context:	callback context
 */
static void EFIAPI
efi_tcg2_notify_exit_boot_services(struct efi_event *event, void *context)
{
	efi_status_t ret;
	struct udevice *dev;

	EFI_ENTRY("%p, %p", event, context);

	event_log.ebs_called = true;

	if (!is_tcg2_protocol_installed()) {
		ret = EFI_SUCCESS;
		goto out;
	}

	if (tcg2_platform_get_tpm2(&dev)) {
		ret = EFI_SECURITY_VIOLATION;
		goto out;
	}

	ret = measure_event(dev, 5, EV_EFI_ACTION,
			    strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
			    (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
	if (ret != EFI_SUCCESS)
		goto out;

	ret = measure_event(dev, 5, EV_EFI_ACTION,
			    strlen(EFI_EXIT_BOOT_SERVICES_SUCCEEDED),
			    (u8 *)EFI_EXIT_BOOT_SERVICES_SUCCEEDED);

out:
	EFI_EXIT(ret);
}

/**
 * efi_tcg2_notify_exit_boot_services_failed()
 *  - notify ExitBootServices() is failed
 *
 * Return:	status code
 */
efi_status_t efi_tcg2_notify_exit_boot_services_failed(void)
{
	struct udevice *dev;
	efi_status_t ret;

	if (!is_tcg2_protocol_installed())
		return EFI_SUCCESS;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_SECURITY_VIOLATION;

	ret = measure_event(dev, 5, EV_EFI_ACTION,
			    strlen(EFI_EXIT_BOOT_SERVICES_INVOCATION),
			    (u8 *)EFI_EXIT_BOOT_SERVICES_INVOCATION);
	if (ret != EFI_SUCCESS)
		goto out;

	ret = measure_event(dev, 5, EV_EFI_ACTION,
			    strlen(EFI_EXIT_BOOT_SERVICES_FAILED),
			    (u8 *)EFI_EXIT_BOOT_SERVICES_FAILED);

out:
	return ret;
}

/**
 * tcg2_measure_secure_boot_variable() - measure secure boot variables
 *
 * @dev:	TPM device
 *
 * Return:	status code
 */
static efi_status_t tcg2_measure_secure_boot_variable(struct udevice *dev)
{
	u8 *data;
	efi_uintn_t data_size;
	u32 count, i;
	efi_status_t ret;
	u8 deployed_mode;
	efi_uintn_t size;
	u32 deployed_audit_pcr_index = 1;

	size = sizeof(deployed_mode);
	ret = efi_get_variable_int(u"DeployedMode", &efi_global_variable_guid,
				   NULL, &size, &deployed_mode, NULL);
	if (ret != EFI_SUCCESS || !deployed_mode)
		deployed_audit_pcr_index = 7;

	count = ARRAY_SIZE(secure_variables);
	for (i = 0; i < count; i++) {
		const efi_guid_t *guid;

		guid = efi_auth_var_get_guid(secure_variables[i].name);

		data = efi_get_var(secure_variables[i].name, guid, &data_size);
		if (!data && !secure_variables[i].accept_empty)
			continue;

		if (u16_strcmp(u"DeployedMode", secure_variables[i].name))
			secure_variables[i].pcr_index = deployed_audit_pcr_index;
		if (u16_strcmp(u"AuditMode", secure_variables[i].name))
			secure_variables[i].pcr_index = deployed_audit_pcr_index;

		ret = tcg2_measure_variable(dev, secure_variables[i].pcr_index,
					    EV_EFI_VARIABLE_DRIVER_CONFIG,
					    secure_variables[i].name, guid,
					    data_size, data);
		free(data);
		if (ret != EFI_SUCCESS)
			goto error;
	}

error:
	return ret;
}

/**
 * efi_tcg2_do_initial_measurement() - do initial measurement
 *
 * Return:	status code
 */
efi_status_t efi_tcg2_do_initial_measurement(void)
{
	efi_status_t ret;
	struct udevice *dev;

	if (!is_tcg2_protocol_installed())
		return EFI_SUCCESS;

	if (tcg2_platform_get_tpm2(&dev))
		return EFI_SECURITY_VIOLATION;

	ret = tcg2_measure_secure_boot_variable(dev);
	if (ret != EFI_SUCCESS)
		goto out;

out:
	return ret;
}

/**
 * efi_tcg2_register() - register EFI_TCG2_PROTOCOL
 *
 * If a TPM2 device is available, the TPM TCG2 Protocol is registered
 *
 * Return:	status code
 */
efi_status_t efi_tcg2_register(void)
{
	efi_status_t ret = EFI_SUCCESS;
	struct udevice *dev;
	struct efi_event *event;
	u32 err;

	if (tcg2_platform_get_tpm2(&dev)) {
		log_warning("Missing TPMv2 device for EFI_TCG_PROTOCOL\n");
		return EFI_SUCCESS;
	}

	/* initialize the TPM as early as possible. */
	err = tpm_auto_start(dev);
	if (err) {
		ret = EFI_DEVICE_ERROR;
		log_err("TPM startup failed\n");
		goto fail;
	}

	ret = efi_init_event_log();
	if (ret != EFI_SUCCESS) {
		tcg2_uninit();
		goto fail;
	}

	ret = efi_install_multiple_protocol_interfaces(&efi_root, &efi_guid_tcg2_protocol,
						       &efi_tcg2_protocol, NULL);
	if (ret != EFI_SUCCESS) {
		tcg2_uninit();
		goto fail;
	}

	ret = efi_create_event(EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,
			       efi_tcg2_notify_exit_boot_services, NULL,
			       NULL, &event);
	if (ret != EFI_SUCCESS) {
		tcg2_uninit();
		goto fail;
	}

	return ret;

fail:
	log_err("Cannot install EFI_TCG2_PROTOCOL\n");
	return ret;
}