lib/efi_loader/efi_esrt.c - u-boot - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  EFI application ESRT tables support
  *
  *  Copyright (C) 2021 Arm Ltd.
  */

 #include <common.h>
 #include <efi_loader.h>
 #include <log.h>
 #include <efi_api.h>
 #include <malloc.h>

 const efi_guid_t efi_esrt_guid = EFI_SYSTEM_RESOURCE_TABLE_GUID;

 static struct efi_system_resource_table *esrt;

 #define EFI_ESRT_VERSION 1

 /**
  * efi_esrt_image_info_to_entry() - copy the information present in a fw image
  * descriptor to a ESRT entry.
  * The function ensures the ESRT entry matches the image_type_id in @img_info.
  * In case of a mismatch we leave the entry unchanged.
  *
  * @img_info:     the source image info descriptor
  * @entry:        pointer to the ESRT entry to be filled
  * @desc_version: the version of the elements in img_info
  * @image_type:   the image type value to be set in the ESRT entry
  * @flags:        the capsule flags value to be set in the ESRT entry
  *
  * Return:
  * - EFI_SUCCESS if the entry is correctly updated
  * - EFI_INVALID_PARAMETER if entry does not match image_type_id in @img_info.
  */
 static efi_status_t
 efi_esrt_image_info_to_entry(struct efi_firmware_image_descriptor *img_info,
 			     struct efi_system_resource_entry *entry,
 			     u32 desc_version, u32 image_type, u32 flags)
 {
 	if (guidcmp(&entry->fw_class, &img_info->image_type_id)) {
 		EFI_PRINT("ESRT entry %pUL mismatches img_type_id %pUL\n",
 			  &entry->fw_class, &img_info->image_type_id);
 		return EFI_INVALID_PARAMETER;
 	}

 	entry->fw_version = img_info->version;

 	entry->fw_type = image_type;
 	entry->capsule_flags = flags;

 	/*
 	 * The field lowest_supported_image_version is only present
 	 * on image info structure of version 2 or greater.
 	 * See the EFI_FIRMWARE_IMAGE_DESCRIPTOR definition in UEFI.
 	 */
 	if (desc_version >= 2)
 		entry->lowest_supported_fw_version =
 			img_info->lowest_supported_image_version;
 	else
 		entry->lowest_supported_fw_version = 0;

 	/*
 	 * The fields last_attempt_version and last_attempt_status
 	 * are only present on image info structure of version 3 or
 	 * greater.
 	 * See the EFI_FIRMWARE_IMAGE_DESCRIPTOR definition in UEFI.
 	 */
 	if (desc_version >= 3) {
 		entry->last_attempt_version =
 			img_info->last_attempt_version;

 		entry->last_attempt_status =
 			img_info->last_attempt_status;
 	} else {
 		entry->last_attempt_version = 0;
 		entry->last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
 	}

 	return EFI_SUCCESS;
 }

 /**
  * efi_esrt_entries_to_size() - Obtain the bytes used by an ESRT
  * datastructure with @num_entries.
  *
  * @num_entries: the number of entries in the ESRT.
  *
  * Return: the number of bytes an ESRT with @num_entries occupies in memory.
  */
 static
 inline u32 efi_esrt_entries_to_size(u32 num_entries)
 {
 	u32 esrt_size = sizeof(struct efi_system_resource_table) +
 		num_entries * sizeof(struct efi_system_resource_entry);

 	return esrt_size;
 }

 /**
  * efi_esrt_allocate_install() - Allocates @num_entries for the ESRT and
  * performs basic ESRT initialization.
  *
  * @num_entries: the number of entries that the ESRT will hold.
  *
  * Return:
  * - pointer to the ESRT if successful.
  * - NULL otherwise.
  */
 static
 efi_status_t efi_esrt_allocate_install(u32 num_entries)
 {
 	efi_status_t ret;
 	struct efi_system_resource_table *new_esrt;
 	u32 size = efi_esrt_entries_to_size(num_entries);
 	efi_guid_t esrt_guid = efi_esrt_guid;

 	/* Reserve memory for ESRT */
 	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, size,
 				(void **)&new_esrt);

 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT cannot allocate memory for %u entries (%u bytes)\n",
 			  num_entries, size);

 		return ret;
 	}

 	new_esrt->fw_resource_count_max = num_entries;
 	new_esrt->fw_resource_count = 0;
 	new_esrt->fw_resource_version = EFI_ESRT_VERSION;

 	/* Install the ESRT in the system configuration table. */
 	ret = efi_install_configuration_table(&esrt_guid, (void *)new_esrt);
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to install the ESRT in the system table\n");
 		return ret;
 	}

 	/* If there was a previous ESRT, deallocate its memory now. */
 	if (esrt)
 		ret = efi_free_pool(esrt);

 	esrt = new_esrt;

 	return EFI_SUCCESS;
 }

 /**
  * esrt_find_entry() - Obtain the ESRT entry for the image with GUID
  * @img_fw_class.
  *
  * If the img_fw_class is not yet present in the ESRT, this function
  * reserves the tail element of the current ESRT as the entry for that fw_class.
  * The number of elements in the ESRT is updated in that case.
  *
  * @img_fw_class: the GUID of the FW image which ESRT entry we want to obtain.
  *
  * Return:
  *  - A pointer to the ESRT entry for the image with GUID img_fw_class,
  *  - NULL if:
  *   - there is no more space in the ESRT,
  *   - ESRT is not initialized,
  */
 static
 struct efi_system_resource_entry *esrt_find_entry(efi_guid_t *img_fw_class)
 {
 	u32 filled_entries;
 	u32 max_entries;
 	struct efi_system_resource_entry *entry;

 	if (!esrt) {
 		EFI_PRINT("ESRT access before initialized\n");
 		return NULL;
 	}

 	filled_entries = esrt->fw_resource_count;
 	entry = esrt->entries;

 	/* Check if the image with img_fw_class is already in the ESRT. */
 	for (u32 idx = 0; idx < filled_entries; idx++) {
 		if (!guidcmp(&entry[idx].fw_class, img_fw_class)) {
 			EFI_PRINT("ESRT found entry for image %pUs at index %u\n",
 				  img_fw_class, idx);
 			return &entry[idx];
 		}
 	}

 	max_entries = esrt->fw_resource_count_max;
 	/*
 	 * Since the image with img_fw_class is not present in the ESRT, check
 	 * if ESRT is full before appending the new entry to it.
 	 */
 	if (filled_entries == max_entries) {
 		EFI_PRINT("ESRT full, this should not happen\n");
 		return NULL;
 	}

 	/*
 	 * This is a new entry for a fw image, increment the element
 	 * number in the table and set the fw_class field.
 	 */
 	esrt->fw_resource_count++;
 	entry[filled_entries].fw_class = *img_fw_class;
 	EFI_PRINT("ESRT allocated new entry for image %pUs at index %u\n",
 		  img_fw_class, filled_entries);

 	return &entry[filled_entries];
 }

 /**
  * efi_esrt_add_from_fmp() - Populates a sequence of ESRT entries from the FW
  * images in the FMP.
  *
  * @fmp: the FMP instance from which FW images are added to the ESRT
  *
  * Return:
  * - EFI_SUCCESS if all the FW images in the FMP are added to the ESRT
  * - Error status otherwise
  */
 static
 efi_status_t efi_esrt_add_from_fmp(struct efi_firmware_management_protocol *fmp)
 {
 	struct efi_system_resource_entry *entry = NULL;
 	size_t info_size = 0;
 	struct efi_firmware_image_descriptor *img_info = NULL;
 	u32 desc_version;
 	u8 desc_count;
 	size_t desc_size;
 	u32 package_version;
 	u16 *package_version_name;
 	efi_status_t ret = EFI_SUCCESS;

 	/*
 	 * TODO: set the field image_type depending on the FW image type
 	 * defined in a platform basis.
 	 */
 	u32 image_type = ESRT_FW_TYPE_UNKNOWN;

 	/* TODO: set the capsule flags as a function of the FW image type. */
 	u32 flags = 0;

 	ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, img_info,
 					   &desc_version, &desc_count,
 					   &desc_size, NULL, NULL));

 	if (ret != EFI_BUFFER_TOO_SMALL) {
 		/*
 		 * An input of info_size=0 should always lead
 		 * fmp->get_image_info to return BUFFER_TO_SMALL.
 		 */
 		EFI_PRINT("Erroneous FMP implementation\n");
 		return EFI_INVALID_PARAMETER;
 	}

 	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, info_size,
 				(void **)&img_info);
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to allocate memory for image info.\n");
 		return ret;
 	}

 	ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, img_info,
 					   &desc_version, &desc_count,
 					   &desc_size, &package_version,
 					   &package_version_name));
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to obtain the FMP image info\n");
 		goto out;
 	}

 	/*
 	 * Iterate over all the FW images in the FMP.
 	 */
 	for (u32 desc_idx = 0; desc_idx < desc_count; desc_idx++) {
 		struct efi_firmware_image_descriptor *cur_img_info =
 			(struct efi_firmware_image_descriptor *)
 			((uintptr_t)img_info + desc_idx * desc_size);

 		/*
 		 * Obtain the ESRT entry for the FW image with fw_class
 		 * equal to cur_img_info->image_type_id.
 		 */
 		entry = esrt_find_entry(&cur_img_info->image_type_id);

 		if (entry) {
 			ret = efi_esrt_image_info_to_entry(cur_img_info, entry,
 							   desc_version,
 							   image_type, flags);
 			if (ret != EFI_SUCCESS)
 				EFI_PRINT("ESRT entry mismatches image_type\n");

 		} else {
 			EFI_PRINT("ESRT failed to add entry for %pUs\n",
 				  &cur_img_info->image_type_id);
 			continue;
 		}
 	}

 out:
 	efi_free_pool(img_info);
 	return EFI_SUCCESS;
 }

 /**
  * efi_esrt_populate() - Populates the ESRT entries from the FMP instances
  * present in the system.
  * If an ESRT already exists, the old ESRT is replaced in the system table.
  * The memory of the old ESRT is deallocated.
  *
  * Return:
  * - EFI_SUCCESS if the ESRT is correctly created
  * - error code otherwise.
  */
 efi_status_t efi_esrt_populate(void)
 {
 	efi_handle_t *base_handle = NULL;
 	efi_handle_t *it_handle;
 	efi_uintn_t no_handles = 0;
 	struct efi_firmware_management_protocol *fmp;
 	efi_status_t ret;
 	u32 num_entries = 0;
 	struct efi_handler *handler;

 	/*
 	 * Obtain the number of registered FMP handles.
 	 */
 	ret = EFI_CALL(efi_locate_handle_buffer(BY_PROTOCOL,
 						&efi_guid_firmware_management_protocol,
 						NULL, &no_handles,
 						(efi_handle_t **)&base_handle));

 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT There are no FMP instances\n");

 		ret = efi_esrt_allocate_install(0);
 		if (ret != EFI_SUCCESS) {
 			EFI_PRINT("ESRT failed to create table with 0 entries\n");
 			return ret;
 		}
 		return EFI_SUCCESS;
 	}

 	EFI_PRINT("ESRT populate esrt from (%zd) available FMP handles\n",
 		  no_handles);

 	/*
 	 * Iterate over all FMPs to determine an upper bound on the number of
 	 * ESRT entries.
 	 */
 	it_handle = base_handle;
 	for (u32 idx = 0; idx < no_handles; idx++, it_handle++) {
 		struct efi_firmware_image_descriptor *img_info = NULL;
 		size_t info_size = 0;
 		u32 desc_version = 0;
 		u8 desc_count = 0;
 		size_t desc_size = 0;
 		u32 package_version;
 		u16 *package_version_name;

 		ret = efi_search_protocol(*it_handle,
 					  &efi_guid_firmware_management_protocol,
 					  &handler);

 		if (ret != EFI_SUCCESS) {
 			EFI_PRINT("ESRT Unable to find FMP handle (%u)\n",
 				  idx);
 			goto out;
 		}
 		fmp = handler->protocol_interface;

 		ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, NULL,
 						   &desc_version, &desc_count,
 						   &desc_size, &package_version,
 						   &package_version_name));

 		if (ret != EFI_BUFFER_TOO_SMALL) {
 			/*
 			 * An input of info_size=0 should always lead
 			 * fmp->get_image_info to return BUFFER_TO_SMALL.
 			 */
 			EFI_PRINT("ESRT erroneous FMP implementation\n");
 			ret = EFI_INVALID_PARAMETER;
 			goto out;
 		}

 		ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, info_size,
 					(void **)&img_info);
 		if (ret != EFI_SUCCESS) {
 			EFI_PRINT("ESRT failed to allocate memory for image info\n");
 			goto out;
 		}

 		/*
 		 * Calls to a FMP get_image_info method do not return the
 		 * desc_count value if the return status differs from EFI_SUCCESS.
 		 * We need to repeat the call to get_image_info with a properly
 		 * sized buffer in order to obtain the real number of images
 		 * handled by the FMP.
 		 */
 		ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, img_info,
 						   &desc_version, &desc_count,
 						   &desc_size, &package_version,
 						   &package_version_name));

 		if (ret != EFI_SUCCESS) {
 			EFI_PRINT("ESRT failed to obtain image info from FMP\n");
 			efi_free_pool(img_info);
 			goto out;
 		}

 		num_entries += desc_count;

 		efi_free_pool(img_info);
 	}

 	EFI_PRINT("ESRT create table with %u entries\n", num_entries);
 	/*
 	 * Allocate an ESRT with the sufficient number of entries to accommodate
 	 * all the FMPs in the system.
 	 */
 	ret = efi_esrt_allocate_install(num_entries);
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to initialize table\n");
 		goto out;
 	}

 	/*
 	 * Populate the ESRT entries with all existing FMP.
 	 */
 	it_handle = base_handle;
 	for (u32 idx = 0; idx < no_handles; idx++, it_handle++) {
 		ret = efi_search_protocol(*it_handle,
 					  &efi_guid_firmware_management_protocol,
 					  &handler);

 		if (ret != EFI_SUCCESS) {
 			EFI_PRINT("ESRT unable to find FMP handle (%u)\n",
 				  idx);
 			break;
 		}
 		fmp = handler->protocol_interface;

 		ret = efi_esrt_add_from_fmp(fmp);
 		if (ret != EFI_SUCCESS)
 			EFI_PRINT("ESRT failed to add FMP to the table\n");
 	}

 out:

 	efi_free_pool(base_handle);

 	return ret;
 }

 /**
  * efi_esrt_new_fmp_notify() - Callback for the EVT_NOTIFY_SIGNAL event raised
  * when a new FMP protocol instance is registered in the system.
  */
 static void EFIAPI efi_esrt_new_fmp_notify(struct efi_event *event,
 					   void *context)
 {
 	efi_status_t ret;

 	EFI_ENTRY();

 	ret = efi_esrt_populate();
 	if (ret != EFI_SUCCESS)
 		EFI_PRINT("ESRT failed to populate ESRT entry\n");

 	EFI_EXIT(ret);
 }

 /**
  * efi_esrt_register() - Install the ESRT system table.
  *
  * Return: status code
  */
 efi_status_t efi_esrt_register(void)
 {
 	struct efi_event *ev = NULL;
 	void *registration;
 	efi_status_t ret;

 	EFI_PRINT("ESRT creation start\n");

 	ret = efi_esrt_populate();
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to initiate the table\n");
 		return ret;
 	}

 	ret = efi_create_event(EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
 			       efi_esrt_new_fmp_notify, NULL, NULL, &ev);
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to create event\n");
 		return ret;
 	}

 	ret = EFI_CALL(efi_register_protocol_notify(&efi_guid_firmware_management_protocol,
 						    ev, &registration));
 	if (ret != EFI_SUCCESS) {
 		EFI_PRINT("ESRT failed to register FMP callback\n");
 		return ret;
 	}

 	EFI_PRINT("ESRT table created\n");

 	return ret;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* EFI application ESRT tables support
	*
	* Copyright (C) 2021 Arm Ltd.
	*/

	#include <common.h>
	#include <efi_loader.h>
	#include <log.h>
	#include <efi_api.h>
	#include <malloc.h>

	const efi_guid_t efi_esrt_guid = EFI_SYSTEM_RESOURCE_TABLE_GUID;

	static struct efi_system_resource_table *esrt;

	#define EFI_ESRT_VERSION 1

	/**
	* efi_esrt_image_info_to_entry() - copy the information present in a fw image
	* descriptor to a ESRT entry.
	* The function ensures the ESRT entry matches the image_type_id in @img_info.
	* In case of a mismatch we leave the entry unchanged.
	*
	* @img_info: the source image info descriptor
	* @entry: pointer to the ESRT entry to be filled
	* @desc_version: the version of the elements in img_info
	* @image_type: the image type value to be set in the ESRT entry
	* @flags: the capsule flags value to be set in the ESRT entry
	*
	* Return:
	* - EFI_SUCCESS if the entry is correctly updated
	* - EFI_INVALID_PARAMETER if entry does not match image_type_id in @img_info.
	*/
	static efi_status_t
	efi_esrt_image_info_to_entry(struct efi_firmware_image_descriptor *img_info,
	struct efi_system_resource_entry *entry,
	u32 desc_version, u32 image_type, u32 flags)
	{
	if (guidcmp(&entry->fw_class, &img_info->image_type_id)) {
	EFI_PRINT("ESRT entry %pUL mismatches img_type_id %pUL\n",
	&entry->fw_class, &img_info->image_type_id);
	return EFI_INVALID_PARAMETER;
	}

	entry->fw_version = img_info->version;

	entry->fw_type = image_type;
	entry->capsule_flags = flags;

	/*
	* The field lowest_supported_image_version is only present
	* on image info structure of version 2 or greater.
	* See the EFI_FIRMWARE_IMAGE_DESCRIPTOR definition in UEFI.
	*/
	if (desc_version >= 2)
	entry->lowest_supported_fw_version =
	img_info->lowest_supported_image_version;
	else
	entry->lowest_supported_fw_version = 0;

	/*
	* The fields last_attempt_version and last_attempt_status
	* are only present on image info structure of version 3 or
	* greater.
	* See the EFI_FIRMWARE_IMAGE_DESCRIPTOR definition in UEFI.
	*/
	if (desc_version >= 3) {
	entry->last_attempt_version =
	img_info->last_attempt_version;

	entry->last_attempt_status =
	img_info->last_attempt_status;
	} else {
	entry->last_attempt_version = 0;
	entry->last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
	}

	return EFI_SUCCESS;
	}

	/**
	* efi_esrt_entries_to_size() - Obtain the bytes used by an ESRT
	* datastructure with @num_entries.
	*
	* @num_entries: the number of entries in the ESRT.
	*
	* Return: the number of bytes an ESRT with @num_entries occupies in memory.
	*/
	static
	inline u32 efi_esrt_entries_to_size(u32 num_entries)
	{
	u32 esrt_size = sizeof(struct efi_system_resource_table) +
	num_entries * sizeof(struct efi_system_resource_entry);

	return esrt_size;
	}

	/**
	* efi_esrt_allocate_install() - Allocates @num_entries for the ESRT and
	* performs basic ESRT initialization.
	*
	* @num_entries: the number of entries that the ESRT will hold.
	*
	* Return:
	* - pointer to the ESRT if successful.
	* - NULL otherwise.
	*/
	static
	efi_status_t efi_esrt_allocate_install(u32 num_entries)
	{
	efi_status_t ret;
	struct efi_system_resource_table *new_esrt;
	u32 size = efi_esrt_entries_to_size(num_entries);
	efi_guid_t esrt_guid = efi_esrt_guid;

	/* Reserve memory for ESRT */
	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, size,
	(void **)&new_esrt);

	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT cannot allocate memory for %u entries (%u bytes)\n",
	num_entries, size);

	return ret;
	}

	new_esrt->fw_resource_count_max = num_entries;
	new_esrt->fw_resource_count = 0;
	new_esrt->fw_resource_version = EFI_ESRT_VERSION;

	/* Install the ESRT in the system configuration table. */
	ret = efi_install_configuration_table(&esrt_guid, (void *)new_esrt);
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to install the ESRT in the system table\n");
	return ret;
	}

	/* If there was a previous ESRT, deallocate its memory now. */
	if (esrt)
	ret = efi_free_pool(esrt);

	esrt = new_esrt;

	return EFI_SUCCESS;
	}

	/**
	* esrt_find_entry() - Obtain the ESRT entry for the image with GUID
	* @img_fw_class.
	*
	* If the img_fw_class is not yet present in the ESRT, this function
	* reserves the tail element of the current ESRT as the entry for that fw_class.
	* The number of elements in the ESRT is updated in that case.
	*
	* @img_fw_class: the GUID of the FW image which ESRT entry we want to obtain.
	*
	* Return:
	* - A pointer to the ESRT entry for the image with GUID img_fw_class,
	* - NULL if:
	* - there is no more space in the ESRT,
	* - ESRT is not initialized,
	*/
	static
	struct efi_system_resource_entry esrt_find_entry(efi_guid_t img_fw_class)
	{
	u32 filled_entries;
	u32 max_entries;
	struct efi_system_resource_entry *entry;

	if (!esrt) {
	EFI_PRINT("ESRT access before initialized\n");
	return NULL;
	}

	filled_entries = esrt->fw_resource_count;
	entry = esrt->entries;

	/* Check if the image with img_fw_class is already in the ESRT. */
	for (u32 idx = 0; idx < filled_entries; idx++) {
	if (!guidcmp(&entry[idx].fw_class, img_fw_class)) {
	EFI_PRINT("ESRT found entry for image %pUs at index %u\n",
	img_fw_class, idx);
	return &entry[idx];
	}
	}

	max_entries = esrt->fw_resource_count_max;
	/*
	* Since the image with img_fw_class is not present in the ESRT, check
	* if ESRT is full before appending the new entry to it.
	*/
	if (filled_entries == max_entries) {
	EFI_PRINT("ESRT full, this should not happen\n");
	return NULL;
	}

	/*
	* This is a new entry for a fw image, increment the element
	* number in the table and set the fw_class field.
	*/
	esrt->fw_resource_count++;
	entry[filled_entries].fw_class = *img_fw_class;
	EFI_PRINT("ESRT allocated new entry for image %pUs at index %u\n",
	img_fw_class, filled_entries);

	return &entry[filled_entries];
	}

	/**
	* efi_esrt_add_from_fmp() - Populates a sequence of ESRT entries from the FW
	* images in the FMP.
	*
	* @fmp: the FMP instance from which FW images are added to the ESRT
	*
	* Return:
	* - EFI_SUCCESS if all the FW images in the FMP are added to the ESRT
	* - Error status otherwise
	*/
	static
	efi_status_t efi_esrt_add_from_fmp(struct efi_firmware_management_protocol *fmp)
	{
	struct efi_system_resource_entry *entry = NULL;
	size_t info_size = 0;
	struct efi_firmware_image_descriptor *img_info = NULL;
	u32 desc_version;
	u8 desc_count;
	size_t desc_size;
	u32 package_version;
	u16 *package_version_name;
	efi_status_t ret = EFI_SUCCESS;

	/*
	* TODO: set the field image_type depending on the FW image type
	* defined in a platform basis.
	*/
	u32 image_type = ESRT_FW_TYPE_UNKNOWN;

	/* TODO: set the capsule flags as a function of the FW image type. */
	u32 flags = 0;

	ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, img_info,
	&desc_version, &desc_count,
	&desc_size, NULL, NULL));

	if (ret != EFI_BUFFER_TOO_SMALL) {
	/*
	* An input of info_size=0 should always lead
	* fmp->get_image_info to return BUFFER_TO_SMALL.
	*/
	EFI_PRINT("Erroneous FMP implementation\n");
	return EFI_INVALID_PARAMETER;
	}

	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, info_size,
	(void **)&img_info);
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to allocate memory for image info.\n");
	return ret;
	}

	ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, img_info,
	&desc_version, &desc_count,
	&desc_size, &package_version,
	&package_version_name));
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to obtain the FMP image info\n");
	goto out;
	}

	/*
	* Iterate over all the FW images in the FMP.
	*/
	for (u32 desc_idx = 0; desc_idx < desc_count; desc_idx++) {
	struct efi_firmware_image_descriptor *cur_img_info =
	(struct efi_firmware_image_descriptor *)
	((uintptr_t)img_info + desc_idx * desc_size);

	/*
	* Obtain the ESRT entry for the FW image with fw_class
	* equal to cur_img_info->image_type_id.
	*/
	entry = esrt_find_entry(&cur_img_info->image_type_id);

	if (entry) {
	ret = efi_esrt_image_info_to_entry(cur_img_info, entry,
	desc_version,
	image_type, flags);
	if (ret != EFI_SUCCESS)
	EFI_PRINT("ESRT entry mismatches image_type\n");

	} else {
	EFI_PRINT("ESRT failed to add entry for %pUs\n",
	&cur_img_info->image_type_id);
	continue;
	}
	}

	out:
	efi_free_pool(img_info);
	return EFI_SUCCESS;
	}

	/**
	* efi_esrt_populate() - Populates the ESRT entries from the FMP instances
	* present in the system.
	* If an ESRT already exists, the old ESRT is replaced in the system table.
	* The memory of the old ESRT is deallocated.
	*
	* Return:
	* - EFI_SUCCESS if the ESRT is correctly created
	* - error code otherwise.
	*/
	efi_status_t efi_esrt_populate(void)
	{
	efi_handle_t *base_handle = NULL;
	efi_handle_t *it_handle;
	efi_uintn_t no_handles = 0;
	struct efi_firmware_management_protocol *fmp;
	efi_status_t ret;
	u32 num_entries = 0;
	struct efi_handler *handler;

	/*
	* Obtain the number of registered FMP handles.
	*/
	ret = EFI_CALL(efi_locate_handle_buffer(BY_PROTOCOL,
	&efi_guid_firmware_management_protocol,
	NULL, &no_handles,
	(efi_handle_t **)&base_handle));

	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT There are no FMP instances\n");

	ret = efi_esrt_allocate_install(0);
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to create table with 0 entries\n");
	return ret;
	}
	return EFI_SUCCESS;
	}

	EFI_PRINT("ESRT populate esrt from (%zd) available FMP handles\n",
	no_handles);

	/*
	* Iterate over all FMPs to determine an upper bound on the number of
	* ESRT entries.
	*/
	it_handle = base_handle;
	for (u32 idx = 0; idx < no_handles; idx++, it_handle++) {
	struct efi_firmware_image_descriptor *img_info = NULL;
	size_t info_size = 0;
	u32 desc_version = 0;
	u8 desc_count = 0;
	size_t desc_size = 0;
	u32 package_version;
	u16 *package_version_name;

	ret = efi_search_protocol(*it_handle,
	&efi_guid_firmware_management_protocol,
	&handler);

	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT Unable to find FMP handle (%u)\n",
	idx);
	goto out;
	}
	fmp = handler->protocol_interface;

	ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, NULL,
	&desc_version, &desc_count,
	&desc_size, &package_version,
	&package_version_name));

	if (ret != EFI_BUFFER_TOO_SMALL) {
	/*
	* An input of info_size=0 should always lead
	* fmp->get_image_info to return BUFFER_TO_SMALL.
	*/
	EFI_PRINT("ESRT erroneous FMP implementation\n");
	ret = EFI_INVALID_PARAMETER;
	goto out;
	}

	ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, info_size,
	(void **)&img_info);
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to allocate memory for image info\n");
	goto out;
	}

	/*
	* Calls to a FMP get_image_info method do not return the
	* desc_count value if the return status differs from EFI_SUCCESS.
	* We need to repeat the call to get_image_info with a properly
	* sized buffer in order to obtain the real number of images
	* handled by the FMP.
	*/
	ret = EFI_CALL(fmp->get_image_info(fmp, &info_size, img_info,
	&desc_version, &desc_count,
	&desc_size, &package_version,
	&package_version_name));

	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to obtain image info from FMP\n");
	efi_free_pool(img_info);
	goto out;
	}

	num_entries += desc_count;

	efi_free_pool(img_info);
	}

	EFI_PRINT("ESRT create table with %u entries\n", num_entries);
	/*
	* Allocate an ESRT with the sufficient number of entries to accommodate
	* all the FMPs in the system.
	*/
	ret = efi_esrt_allocate_install(num_entries);
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to initialize table\n");
	goto out;
	}

	/*
	* Populate the ESRT entries with all existing FMP.
	*/
	it_handle = base_handle;
	for (u32 idx = 0; idx < no_handles; idx++, it_handle++) {
	ret = efi_search_protocol(*it_handle,
	&efi_guid_firmware_management_protocol,
	&handler);

	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT unable to find FMP handle (%u)\n",
	idx);
	break;
	}
	fmp = handler->protocol_interface;

	ret = efi_esrt_add_from_fmp(fmp);
	if (ret != EFI_SUCCESS)
	EFI_PRINT("ESRT failed to add FMP to the table\n");
	}

	out:

	efi_free_pool(base_handle);

	return ret;
	}

	/**
	* efi_esrt_new_fmp_notify() - Callback for the EVT_NOTIFY_SIGNAL event raised
	* when a new FMP protocol instance is registered in the system.
	*/
	static void EFIAPI efi_esrt_new_fmp_notify(struct efi_event *event,
	void *context)
	{
	efi_status_t ret;

	EFI_ENTRY();

	ret = efi_esrt_populate();
	if (ret != EFI_SUCCESS)
	EFI_PRINT("ESRT failed to populate ESRT entry\n");

	EFI_EXIT(ret);
	}

	/**
	* efi_esrt_register() - Install the ESRT system table.
	*
	* Return: status code
	*/
	efi_status_t efi_esrt_register(void)
	{
	struct efi_event *ev = NULL;
	void *registration;
	efi_status_t ret;

	EFI_PRINT("ESRT creation start\n");

	ret = efi_esrt_populate();
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to initiate the table\n");
	return ret;
	}

	ret = efi_create_event(EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
	efi_esrt_new_fmp_notify, NULL, NULL, &ev);
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to create event\n");
	return ret;
	}

	ret = EFI_CALL(efi_register_protocol_notify(&efi_guid_firmware_management_protocol,
	ev, &registration));
	if (ret != EFI_SUCCESS) {
	EFI_PRINT("ESRT failed to register FMP callback\n");
	return ret;
	}

	EFI_PRINT("ESRT table created\n");

	return ret;
	}