efi_boottime.c

	r = efi_search_protocol(handle, protocol, &handler);
	if (r != EFI_SUCCESS)
		goto out;

	/* Count entries */
	count = 0;
	list_for_each_entry(item, &handler->open_infos, link) {
		if (item->info.open_count)
			++count;
	}
	*entry_count = count;
	*entry_buffer = NULL;
	if (!count) {
		r = EFI_SUCCESS;
		goto out;
	}

	/* Copy entries */
	buffer_size = count * sizeof(struct efi_open_protocol_info_entry);
	r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, buffer_size,
			      (void **)entry_buffer);
	if (r != EFI_SUCCESS)
		goto out;
	list_for_each_entry_reverse(item, &handler->open_infos, link) {
		if (item->info.open_count)
			(*entry_buffer)[--count] = item->info;
	}
out:
	return EFI_EXIT(r);
}

/*
 * Get protocols installed on a handle.
 *
 * This function implements the ProtocolsPerHandleService.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @handle			handle for which the information is retrieved
 * @protocol_buffer		buffer with protocol GUIDs
 * @protocol_buffer_count	number of entries in the buffer
 * @return			status code
 */
static efi_status_t EFIAPI efi_protocols_per_handle(
			efi_handle_t handle, efi_guid_t ***protocol_buffer,
			efi_uintn_t *protocol_buffer_count)
{
	unsigned long buffer_size;
	struct efi_object *efiobj;
	struct list_head *protocol_handle;
	efi_status_t r;

	EFI_ENTRY("%p, %p, %p", handle, protocol_buffer,
		  protocol_buffer_count);

	if (!handle || !protocol_buffer || !protocol_buffer_count)
		return EFI_EXIT(EFI_INVALID_PARAMETER);

	*protocol_buffer = NULL;
	*protocol_buffer_count = 0;

	efiobj = efi_search_obj(handle);
	if (!efiobj)
		return EFI_EXIT(EFI_INVALID_PARAMETER);

	/* Count protocols */
	list_for_each(protocol_handle, &efiobj->protocols) {
		++*protocol_buffer_count;
	}

	/* Copy guids */
	if (*protocol_buffer_count) {
		size_t j = 0;

		buffer_size = sizeof(efi_guid_t *) * *protocol_buffer_count;
		r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, buffer_size,
				      (void **)protocol_buffer);
		if (r != EFI_SUCCESS)
			return EFI_EXIT(r);
		list_for_each(protocol_handle, &efiobj->protocols) {
			struct efi_handler *protocol;

			protocol = list_entry(protocol_handle,
					      struct efi_handler, link);
			(*protocol_buffer)[j] = (void *)protocol->guid;
			++j;
		}
	}

	return EFI_EXIT(EFI_SUCCESS);
}

/*
 * Locate handles implementing a protocol.
 *
 * This function implements the LocateHandleBuffer service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @search_type		selection criterion
 * @protocol		GUID of the protocol
 * @search_key		registration key
 * @no_handles		number of returned handles
 * @buffer		buffer with the returned handles
 * @return		status code
 */
static efi_status_t EFIAPI efi_locate_handle_buffer(
			enum efi_locate_search_type search_type,
			const efi_guid_t *protocol, void *search_key,
			efi_uintn_t *no_handles, efi_handle_t **buffer)
{
	efi_status_t r;
	efi_uintn_t buffer_size = 0;

	EFI_ENTRY("%d, %pUl, %p, %p, %p", search_type, protocol, search_key,
		  no_handles, buffer);

	if (!no_handles || !buffer) {
		r = EFI_INVALID_PARAMETER;
		goto out;
	}
	*no_handles = 0;
	*buffer = NULL;
	r = efi_locate_handle(search_type, protocol, search_key, &buffer_size,
			      *buffer);
	if (r != EFI_BUFFER_TOO_SMALL)
		goto out;
	r = efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, buffer_size,
			      (void **)buffer);
	if (r != EFI_SUCCESS)
		goto out;
	r = efi_locate_handle(search_type, protocol, search_key, &buffer_size,
			      *buffer);
	if (r == EFI_SUCCESS)
		*no_handles = buffer_size / sizeof(efi_handle_t);
out:
	return EFI_EXIT(r);
}

/*
 * Find an interface implementing a protocol.
 *
 * This function implements the LocateProtocol service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @protocol		GUID of the protocol
 * @registration	registration key passed to the notification function
 * @protocol_interface	interface implementing the protocol
 * @return		status code
 */
static efi_status_t EFIAPI efi_locate_protocol(const efi_guid_t *protocol,
					       void *registration,
					       void **protocol_interface)
{
	struct list_head *lhandle;
	efi_status_t ret;

	EFI_ENTRY("%pUl, %p, %p", protocol, registration, protocol_interface);

	if (!protocol || !protocol_interface)
		return EFI_EXIT(EFI_INVALID_PARAMETER);

	list_for_each(lhandle, &efi_obj_list) {
		struct efi_object *efiobj;
		struct efi_handler *handler;

		efiobj = list_entry(lhandle, struct efi_object, link);

		ret = efi_search_protocol(efiobj->handle, protocol, &handler);
		if (ret == EFI_SUCCESS) {
			*protocol_interface = handler->protocol_interface;
			return EFI_EXIT(EFI_SUCCESS);
		}
	}
	*protocol_interface = NULL;

	return EFI_EXIT(EFI_NOT_FOUND);
}

/*
 * Get the device path and handle of an device implementing a protocol.
 *
 * This function implements the LocateDevicePath service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @protocol		GUID of the protocol
 * @device_path		device path
 * @device		handle of the device
 * @return		status code
 */
static efi_status_t EFIAPI efi_locate_device_path(
			const efi_guid_t *protocol,
			struct efi_device_path **device_path,
			efi_handle_t *device)
{
	struct efi_device_path *dp;
	size_t i;
	struct efi_handler *handler;
	efi_handle_t *handles;
	size_t len, len_dp;
	size_t len_best = 0;
	efi_uintn_t no_handles;
	u8 *remainder;
	efi_status_t ret;

	EFI_ENTRY("%pUl, %p, %p", protocol, device_path, device);

	if (!protocol || !device_path || !*device_path || !device) {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	/* Find end of device path */
	len = efi_dp_size(*device_path);

	/* Get all handles implementing the protocol */
	ret = EFI_CALL(efi_locate_handle_buffer(BY_PROTOCOL, protocol, NULL,
						&no_handles, &handles));
	if (ret != EFI_SUCCESS)
		goto out;

	for (i = 0; i < no_handles; ++i) {
		/* Find the device path protocol */
		ret = efi_search_protocol(handles[i], &efi_guid_device_path,
					  &handler);
		if (ret != EFI_SUCCESS)
			continue;
		dp = (struct efi_device_path *)handler->protocol_interface;
		len_dp = efi_dp_size(dp);
		/*
		 * This handle can only be a better fit
		 * if its device path length is longer than the best fit and
		 * if its device path length is shorter of equal the searched
		 * device path.
		 */
		if (len_dp <= len_best || len_dp > len)
			continue;
		/* Check if dp is a subpath of device_path */
		if (memcmp(*device_path, dp, len_dp))
			continue;
		*device = handles[i];
		len_best = len_dp;
	}
	if (len_best) {
		remainder = (u8 *)*device_path + len_best;
		*device_path = (struct efi_device_path *)remainder;
		ret = EFI_SUCCESS;
	} else {
		ret = EFI_NOT_FOUND;
	}
out:
	return EFI_EXIT(ret);
}

/*
 * Install multiple protocol interfaces.
 *
 * This function implements the MultipleProtocolInterfaces service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @handle	handle on which the protocol interfaces shall be installed
 * @...		NULL terminated argument list with pairs of protocol GUIDS and
 *		interfaces
 * @return	status code
 */
static efi_status_t EFIAPI efi_install_multiple_protocol_interfaces(
			void **handle, ...)
{
	EFI_ENTRY("%p", handle);

	va_list argptr;
	const efi_guid_t *protocol;
	void *protocol_interface;
	efi_status_t r = EFI_SUCCESS;
	int i = 0;

	if (!handle)
		return EFI_EXIT(EFI_INVALID_PARAMETER);

	va_start(argptr, handle);
	for (;;) {
		protocol = va_arg(argptr, efi_guid_t*);
		if (!protocol)
			break;
		protocol_interface = va_arg(argptr, void*);
		r = EFI_CALL(efi_install_protocol_interface(
						handle, protocol,
						EFI_NATIVE_INTERFACE,
						protocol_interface));
		if (r != EFI_SUCCESS)
			break;
		i++;
	}
	va_end(argptr);
	if (r == EFI_SUCCESS)
		return EFI_EXIT(r);

	/* If an error occurred undo all changes. */
	va_start(argptr, handle);
	for (; i; --i) {
		protocol = va_arg(argptr, efi_guid_t*);
		protocol_interface = va_arg(argptr, void*);
		EFI_CALL(efi_uninstall_protocol_interface(handle, protocol,
							  protocol_interface));
	}
	va_end(argptr);

	return EFI_EXIT(r);
}

/*
 * Uninstall multiple protocol interfaces.
 *
 * This function implements the UninstallMultipleProtocolInterfaces service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @handle	handle from which the protocol interfaces shall be removed
 * @...		NULL terminated argument list with pairs of protocol GUIDS and
 *		interfaces
 * @return	status code
 */
static efi_status_t EFIAPI efi_uninstall_multiple_protocol_interfaces(
			void *handle, ...)
{
	EFI_ENTRY("%p", handle);

	va_list argptr;
	const efi_guid_t *protocol;
	void *protocol_interface;
	efi_status_t r = EFI_SUCCESS;
	size_t i = 0;

	if (!handle)
		return EFI_EXIT(EFI_INVALID_PARAMETER);

	va_start(argptr, handle);
	for (;;) {
		protocol = va_arg(argptr, efi_guid_t*);
		if (!protocol)
			break;
		protocol_interface = va_arg(argptr, void*);
		r = EFI_CALL(efi_uninstall_protocol_interface(
						handle, protocol,
						protocol_interface));
		if (r != EFI_SUCCESS)
			break;
		i++;
	}
	va_end(argptr);
	if (r == EFI_SUCCESS)
		return EFI_EXIT(r);

	/* If an error occurred undo all changes. */
	va_start(argptr, handle);
	for (; i; --i) {
		protocol = va_arg(argptr, efi_guid_t*);
		protocol_interface = va_arg(argptr, void*);
		EFI_CALL(efi_install_protocol_interface(&handle, protocol,
							EFI_NATIVE_INTERFACE,
							protocol_interface));
	}
	va_end(argptr);

	return EFI_EXIT(r);
}

/*
 * Calculate cyclic redundancy code.
 *
 * This function implements the CalculateCrc32 service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @data	buffer with data
 * @data_size	size of buffer in bytes
 * @crc32_p	cyclic redundancy code
 * @return	status code
 */
static efi_status_t EFIAPI efi_calculate_crc32(void *data,
					       unsigned long data_size,
					       uint32_t *crc32_p)
{
	EFI_ENTRY("%p, %ld", data, data_size);
	*crc32_p = crc32(0, data, data_size);
	return EFI_EXIT(EFI_SUCCESS);
}

/*
 * Copy memory.
 *
 * This function implements the CopyMem service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @destination		destination of the copy operation
 * @source		source of the copy operation
 * @length		number of bytes to copy
 */
static void EFIAPI efi_copy_mem(void *destination, const void *source,
				size_t length)
{
	EFI_ENTRY("%p, %p, %ld", destination, source, (unsigned long)length);
	memcpy(destination, source, length);
	EFI_EXIT(EFI_SUCCESS);
}

/*
 * Fill memory with a byte value.
 *
 * This function implements the SetMem service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @buffer		buffer to fill
 * @size		size of buffer in bytes
 * @value		byte to copy to the buffer
 */
static void EFIAPI efi_set_mem(void *buffer, size_t size, uint8_t value)
{
	EFI_ENTRY("%p, %ld, 0x%x", buffer, (unsigned long)size, value);
	memset(buffer, value, size);
	EFI_EXIT(EFI_SUCCESS);
}

/*
 * Open protocol interface on a handle.
 *
 * @handler		handler of a protocol
 * @protocol_interface	interface implementing the protocol
 * @agent_handle	handle of the driver
 * @controller_handle	handle of the controller
 * @attributes		attributes indicating how to open the protocol
 * @return		status code
 */
static efi_status_t efi_protocol_open(
			struct efi_handler *handler,
			void **protocol_interface, void *agent_handle,
			void *controller_handle, uint32_t attributes)
{
	struct efi_open_protocol_info_item *item;
	struct efi_open_protocol_info_entry *match = NULL;
	bool opened_by_driver = false;
	bool opened_exclusive = false;

	/* If there is no agent, only return the interface */
	if (!agent_handle)
		goto out;

	/* For TEST_PROTOCOL ignore interface attribute */
	if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
		*protocol_interface = NULL;

	/*
	 * Check if the protocol is already opened by a driver with the same
	 * attributes or opened exclusively
	 */
	list_for_each_entry(item, &handler->open_infos, link) {
		if (item->info.agent_handle == agent_handle) {
			if ((attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) &&
			    (item->info.attributes == attributes))
				return EFI_ALREADY_STARTED;
		}
		if (item->info.attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE)
			opened_exclusive = true;
	}

	/* Only one controller can open the protocol exclusively */
	if (opened_exclusive && attributes &
	    (EFI_OPEN_PROTOCOL_EXCLUSIVE | EFI_OPEN_PROTOCOL_BY_DRIVER))
		return EFI_ACCESS_DENIED;

	/* Prepare exclusive opening */
	if (attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE) {
		/* Try to disconnect controllers */
		list_for_each_entry(item, &handler->open_infos, link) {
			if (item->info.attributes ==
					EFI_OPEN_PROTOCOL_BY_DRIVER)
				EFI_CALL(efi_disconnect_controller(
						item->info.controller_handle,
						item->info.agent_handle,
						NULL));
		}
		opened_by_driver = false;
		/* Check if all controllers are disconnected */
		list_for_each_entry(item, &handler->open_infos, link) {
			if (item->info.attributes & EFI_OPEN_PROTOCOL_BY_DRIVER)
				opened_by_driver = true;
		}
		/* Only one controller can be conncected */
		if (opened_by_driver)
			return EFI_ACCESS_DENIED;
	}

	/* Find existing entry */
	list_for_each_entry(item, &handler->open_infos, link) {
		if (item->info.agent_handle == agent_handle &&
		    item->info.controller_handle == controller_handle)
			match = &item->info;
	}
	/* None found, create one */
	if (!match) {
		match = efi_create_open_info(handler);
		if (!match)
			return EFI_OUT_OF_RESOURCES;
	}

	match->agent_handle = agent_handle;
	match->controller_handle = controller_handle;
	match->attributes = attributes;
	match->open_count++;

out:
	/* For TEST_PROTOCOL ignore interface attribute. */
	if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL)
		*protocol_interface = handler->protocol_interface;

	return EFI_SUCCESS;
}

/*
 * Open protocol interface on a handle.
 *
 * This function implements the OpenProtocol interface.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @handle		handle on which the protocol shall be opened
 * @protocol		GUID of the protocol
 * @protocol_interface	interface implementing the protocol
 * @agent_handle	handle of the driver
 * @controller_handle	handle of the controller
 * @attributes		attributes indicating how to open the protocol
 * @return		status code
 */
static efi_status_t EFIAPI efi_open_protocol(
			void *handle, const efi_guid_t *protocol,
			void **protocol_interface, void *agent_handle,
			void *controller_handle, uint32_t attributes)
{
	struct efi_handler *handler;
	efi_status_t r = EFI_INVALID_PARAMETER;

	EFI_ENTRY("%p, %pUl, %p, %p, %p, 0x%x", handle, protocol,
		  protocol_interface, agent_handle, controller_handle,
		  attributes);

	if (!handle || !protocol ||
	    (!protocol_interface && attributes !=
	     EFI_OPEN_PROTOCOL_TEST_PROTOCOL)) {
		goto out;
	}

	switch (attributes) {
	case EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL:
	case EFI_OPEN_PROTOCOL_GET_PROTOCOL:
	case EFI_OPEN_PROTOCOL_TEST_PROTOCOL:
		break;
	case EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER:
		if (controller_handle == handle)
			goto out;
		/* fall-through */
	case EFI_OPEN_PROTOCOL_BY_DRIVER:
	case EFI_OPEN_PROTOCOL_BY_DRIVER | EFI_OPEN_PROTOCOL_EXCLUSIVE:
		/* Check that the controller handle is valid */
		if (!efi_search_obj(controller_handle))
			goto out;
		/* fall-through */
	case EFI_OPEN_PROTOCOL_EXCLUSIVE:
		/* Check that the agent handle is valid */
		if (!efi_search_obj(agent_handle))
			goto out;
		break;
	default:
		goto out;
	}

	r = efi_search_protocol(handle, protocol, &handler);
	if (r != EFI_SUCCESS)
		goto out;

	r = efi_protocol_open(handler, protocol_interface, agent_handle,
			      controller_handle, attributes);
out:
	return EFI_EXIT(r);
}

/*
 * Get interface of a protocol on a handle.
 *
 * This function implements the HandleProtocol service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @handle		handle on which the protocol shall be opened
 * @protocol		GUID of the protocol
 * @protocol_interface  interface implementing the protocol
 * @return		status code
 */
static efi_status_t EFIAPI efi_handle_protocol(efi_handle_t handle,
					       const efi_guid_t *protocol,
					       void **protocol_interface)
{
	return efi_open_protocol(handle, protocol, protocol_interface, NULL,
				 NULL, EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL);
}

static efi_status_t efi_bind_controller(
			efi_handle_t controller_handle,
			efi_handle_t driver_image_handle,
			struct efi_device_path *remain_device_path)
{
	struct efi_driver_binding_protocol *binding_protocol;
	efi_status_t r;

	r = EFI_CALL(efi_open_protocol(driver_image_handle,
				       &efi_guid_driver_binding_protocol,
				       (void **)&binding_protocol,
				       driver_image_handle, NULL,
				       EFI_OPEN_PROTOCOL_GET_PROTOCOL));
	if (r != EFI_SUCCESS)
		return r;
	r = EFI_CALL(binding_protocol->supported(binding_protocol,
						 controller_handle,
						 remain_device_path));
	if (r == EFI_SUCCESS)
		r = EFI_CALL(binding_protocol->start(binding_protocol,
						     controller_handle,
						     remain_device_path));
	EFI_CALL(efi_close_protocol(driver_image_handle,
				    &efi_guid_driver_binding_protocol,
				    driver_image_handle, NULL));
	return r;
}

static efi_status_t efi_connect_single_controller(
			efi_handle_t controller_handle,
			efi_handle_t *driver_image_handle,
			struct efi_device_path *remain_device_path)
{
	efi_handle_t *buffer;
	size_t count;
	size_t i;
	efi_status_t r;
	size_t connected = 0;

	/* Get buffer with all handles with driver binding protocol */
	r = EFI_CALL(efi_locate_handle_buffer(BY_PROTOCOL,
					      &efi_guid_driver_binding_protocol,
					      NULL, &count, &buffer));
	if (r != EFI_SUCCESS)
		return r;

	/*  Context Override */
	if (driver_image_handle) {
		for (; *driver_image_handle; ++driver_image_handle) {
			for (i = 0; i < count; ++i) {
				if (buffer[i] == *driver_image_handle) {
					buffer[i] = NULL;
					r = efi_bind_controller(
							controller_handle,
							*driver_image_handle,
							remain_device_path);
					/*
					 * For drivers that do not support the
					 * controller or are already connected
					 * we receive an error code here.
					 */
					if (r == EFI_SUCCESS)
						++connected;
				}
			}
		}
	}

	/*
	 * TODO: Some overrides are not yet implemented:
	 * - Platform Driver Override
	 * - Driver Family Override Search
	 * - Bus Specific Driver Override
	 */

	/* Driver Binding Search */
	for (i = 0; i < count; ++i) {
		if (buffer[i]) {
			r = efi_bind_controller(controller_handle,
						buffer[i],
						remain_device_path);
			if (r == EFI_SUCCESS)
				++connected;
		}
	}

	efi_free_pool(buffer);
	if (!connected)
		return EFI_NOT_FOUND;
	return EFI_SUCCESS;
}

/*
 * Connect a controller to a driver.
 *
 * This function implements the ConnectController service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * First all driver binding protocol handles are tried for binding drivers.
 * Afterwards all handles that have openened a protocol of the controller
 * with EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER are connected to drivers.
 *
 * @controller_handle	handle of the controller
 * @driver_image_handle	handle of the driver
 * @remain_device_path	device path of a child controller
 * @recursive		true to connect all child controllers
 * @return		status code
 */
static efi_status_t EFIAPI efi_connect_controller(
			efi_handle_t controller_handle,
			efi_handle_t *driver_image_handle,
			struct efi_device_path *remain_device_path,
			bool recursive)
{
	efi_status_t r;
	efi_status_t ret = EFI_NOT_FOUND;
	struct efi_object *efiobj;

	EFI_ENTRY("%p, %p, %p, %d", controller_handle, driver_image_handle,
		  remain_device_path, recursive);

	efiobj = efi_search_obj(controller_handle);
	if (!efiobj) {
		ret = EFI_INVALID_PARAMETER;
		goto out;
	}

	r = efi_connect_single_controller(controller_handle,
					  driver_image_handle,
					  remain_device_path);
	if (r == EFI_SUCCESS)
		ret = EFI_SUCCESS;
	if (recursive) {
		struct efi_handler *handler;
		struct efi_open_protocol_info_item *item;

		list_for_each_entry(handler, &efiobj->protocols, link) {
			list_for_each_entry(item, &handler->open_infos, link) {
				if (item->info.attributes &
				    EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) {
					r = EFI_CALL(efi_connect_controller(
						item->info.controller_handle,
						driver_image_handle,
						remain_device_path,
						recursive));
					if (r == EFI_SUCCESS)
						ret = EFI_SUCCESS;
				}
			}
		}
	}
	/*  Check for child controller specified by end node */
	if (ret != EFI_SUCCESS && remain_device_path &&
	    remain_device_path->type == DEVICE_PATH_TYPE_END)
		ret = EFI_SUCCESS;
out:
	return EFI_EXIT(ret);
}

/*
 * Get all child controllers associated to a driver.
 * The allocated buffer has to be freed with free().
 *
 * @efiobj			handle of the controller
 * @driver_handle		handle of the driver
 * @number_of_children		number of child controllers
 * @child_handle_buffer		handles of the the child controllers
 */
static efi_status_t efi_get_child_controllers(
				struct efi_object *efiobj,
				efi_handle_t driver_handle,
				efi_uintn_t *number_of_children,
				efi_handle_t **child_handle_buffer)
{
	struct efi_handler *handler;
	struct efi_open_protocol_info_item *item;
	efi_uintn_t count = 0, i;
	bool duplicate;

	/* Count all child controller associations */
	list_for_each_entry(handler, &efiobj->protocols, link) {
		list_for_each_entry(item, &handler->open_infos, link) {
			if (item->info.agent_handle == driver_handle &&
			    item->info.attributes &
			    EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER)
				++count;
		}
	}
	/*
	 * Create buffer. In case of duplicate child controller assignments
	 * the buffer will be too large. But that does not harm.
	 */
	*number_of_children = 0;
	*child_handle_buffer = calloc(count, sizeof(efi_handle_t));
	if (!*child_handle_buffer)
		return EFI_OUT_OF_RESOURCES;
	/* Copy unique child handles */
	list_for_each_entry(handler, &efiobj->protocols, link) {
		list_for_each_entry(item, &handler->open_infos, link) {
			if (item->info.agent_handle == driver_handle &&
			    item->info.attributes &
			    EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) {
				/* Check this is a new child controller */
				duplicate = false;
				for (i = 0; i < *number_of_children; ++i) {
					if ((*child_handle_buffer)[i] ==
					    item->info.controller_handle)
						duplicate = true;
				}
				/* Copy handle to buffer */
				if (!duplicate) {
					i = (*number_of_children)++;
					(*child_handle_buffer)[i] =
						item->info.controller_handle;
				}
			}
		}
	}
	return EFI_SUCCESS;
}

/*
 * Disconnect a controller from a driver.
 *
 * This function implements the DisconnectController service.
 * See the Unified Extensible Firmware Interface (UEFI) specification
 * for details.
 *
 * @controller_handle	handle of the controller
 * @driver_image_handle handle of the driver
 * @child_handle	handle of the child to destroy
 * @return		status code
 */
static efi_status_t EFIAPI efi_disconnect_controller(
				efi_handle_t controller_handle,
				efi_handle_t driver_image_handle,
				efi_handle_t child_handle)
{
	struct efi_driver_binding_protocol *binding_protocol;
	efi_handle_t *child_handle_buffer = NULL;
	size_t number_of_children = 0;
	efi_status_t r;
	size_t stop_count = 0;
	struct efi_object *efiobj;

	EFI_ENTRY("%p, %p, %p", controller_handle, driver_image_handle,
		  child_handle);

	efiobj = efi_search_obj(controller_handle);
	if (!efiobj) {
		r = EFI_INVALID_PARAMETER;
		goto out;
	}

	if (child_handle && !efi_search_obj(child_handle)) {
		r = EFI_INVALID_PARAMETER;
		goto out;
	}

	/* If no driver handle is supplied, disconnect all drivers */
	if (!driver_image_handle) {
		r = efi_disconnect_all_drivers(efiobj, NULL, child_handle);
		goto out;
	}

	/* Create list of child handles */
	if (child_handle) {
		number_of_children = 1;
		child_handle_buffer = &child_handle;
	} else {
		efi_get_child_controllers(efiobj,
					  driver_image_handle,
					  &number_of_children,
					  &child_handle_buffer);
	}

	/* Get the driver binding protocol */
	r = EFI_CALL(efi_open_protocol(driver_image_handle,
				       &efi_guid_driver_binding_protocol,
				       (void **)&binding_protocol,
				       driver_image_handle, NULL,
				       EFI_OPEN_PROTOCOL_GET_PROTOCOL));
	if (r != EFI_SUCCESS)
		goto out;
	/* Remove the children */
	if (number_of_children) {
		r = EFI_CALL(binding_protocol->stop(binding_protocol,
						    controller_handle,
						    number_of_children,
						    child_handle_buffer));
		if (r == EFI_SUCCESS)
			++stop_count;
	}
	/* Remove the driver */
	if (!child_handle)
		r = EFI_CALL(binding_protocol->stop(binding_protocol,
						    controller_handle,
						    0, NULL));
	if (r == EFI_SUCCESS)
		++stop_count;
	EFI_CALL(efi_close_protocol(driver_image_handle,
				    &efi_guid_driver_binding_protocol,
				    driver_image_handle, NULL));

	if (stop_count)
		r = EFI_SUCCESS;
	else
		r = EFI_NOT_FOUND;
out:
	if (!child_handle)
		free(child_handle_buffer);
	return EFI_EXIT(r);
}

static const struct efi_boot_services efi_boot_services = {
	.hdr = {
		.headersize = sizeof(struct efi_table_hdr),
	},
	.raise_tpl = efi_raise_tpl,
	.restore_tpl = efi_restore_tpl,
	.allocate_pages = efi_allocate_pages_ext,
	.free_pages = efi_free_pages_ext,
	.get_memory_map = efi_get_memory_map_ext,
	.allocate_pool = efi_allocate_pool_ext,
	.free_pool = efi_free_pool_ext,
	.create_event = efi_create_event_ext,
	.set_timer = efi_set_timer_ext,
	.wait_for_event = efi_wait_for_event,
	.signal_event = efi_signal_event_ext,
	.close_event = efi_close_event,
	.check_event = efi_check_event,
	.install_protocol_interface = efi_install_protocol_interface,
	.reinstall_protocol_interface = efi_reinstall_protocol_interface,
	.uninstall_protocol_interface = efi_uninstall_protocol_interface,
	.handle_protocol = efi_handle_protocol,
	.reserved = NULL,
	.register_protocol_notify = efi_register_protocol_notify,
	.locate_handle = efi_locate_handle_ext,
	.locate_device_path = efi_locate_device_path,
	.install_configuration_table = efi_install_configuration_table_ext,
	.load_image = efi_load_image,
	.start_image = efi_start_image,
	.exit = efi_exit,
	.unload_image = efi_unload_image,
	.exit_boot_services = efi_exit_boot_services,
	.get_next_monotonic_count = efi_get_next_monotonic_count,
	.stall = efi_stall,
	.set_watchdog_timer = efi_set_watchdog_timer,
	.connect_controller = efi_connect_controller,
	.disconnect_controller = efi_disconnect_controller,
	.open_protocol = efi_open_protocol,
	.close_protocol = efi_close_protocol,
	.open_protocol_information = efi_open_protocol_information,
	.protocols_per_handle = efi_protocols_per_handle,
	.locate_handle_buffer = efi_locate_handle_buffer,
	.locate_protocol = efi_locate_protocol,
	.install_multiple_protocol_interfaces =
			efi_install_multiple_protocol_interfaces,
	.uninstall_multiple_protocol_interfaces =
			efi_uninstall_multiple_protocol_interfaces,
	.calculate_crc32 = efi_calculate_crc32,
	.copy_mem = efi_copy_mem,
	.set_mem = efi_set_mem,
	.create_event_ex = efi_create_event_ex,
};

static uint16_t __efi_runtime_data firmware_vendor[] = L"Das U-Boot";

struct efi_system_table __efi_runtime_data systab = {
	.hdr = {
		.signature = EFI_SYSTEM_TABLE_SIGNATURE,
		.revision = 2 << 16 | 70, /* 2.7 */
		.headersize = sizeof(struct efi_table_hdr),
	},
	.fw_vendor = (long)firmware_vendor,
	.con_in = (void *)&efi_con_in,
	.con_out = (void *)&efi_con_out,
	.std_err = (void *)&efi_con_out,
	.runtime = (void *)&efi_runtime_services,
	.boottime = (void *)&efi_boot_services,
	.nr_tables = 0,
	.tables = (void *)efi_conf_table,
};