Merge tag 'efi-2023-01-rc1' of https://source.denx.de/u-boot/custodians/u-boot-efi

Pull request for efi-2023-01-rc1

UEFI:

* Provide driver binding protocol to registered events for block devices
* Code simplification and refactoring
* Fix pylint errors in test_efi_secboot

Other:

* Improve checks for register ranges

10 files changed, 266 insertions, 134 deletions

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 1bfd094e89f..e776d25830f 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2590,35 +2590,31 @@ found:
 }
 
 /**
- * efi_install_multiple_protocol_interfaces() - Install multiple protocol
+ * efi_install_multiple_protocol_interfaces_int() - Install multiple protocol
  *                                              interfaces
  * @handle: handle on which the protocol interfaces shall be installed
- * @...:    NULL terminated argument list with pairs of protocol GUIDS and
- *          interfaces
+ * @argptr: va_list of args
  *
- * This function implements the MultipleProtocolInterfaces service.
- *
- * See the Unified Extensible Firmware Interface (UEFI) specification for
- * details.
+ * Core functionality of efi_install_multiple_protocol_interfaces
+ * Must not be called directly
  *
  * Return: status code
  */
-efi_status_t EFIAPI efi_install_multiple_protocol_interfaces
-				(efi_handle_t *handle, ...)
+static efi_status_t EFIAPI
+efi_install_multiple_protocol_interfaces_int(efi_handle_t *handle,
+					     efi_va_list argptr)
 {
-	EFI_ENTRY("%p", handle);
-
-	efi_va_list argptr;
 	const efi_guid_t *protocol;
 	void *protocol_interface;
 	efi_handle_t old_handle;
-	efi_status_t r = EFI_SUCCESS;
+	efi_status_t ret = EFI_SUCCESS;
 	int i = 0;
+	efi_va_list argptr_copy;
 
 	if (!handle)
-		return EFI_EXIT(EFI_INVALID_PARAMETER);
+		return EFI_INVALID_PARAMETER;
 
-	efi_va_start(argptr, handle);
+	efi_va_copy(argptr_copy, argptr);
 	for (;;) {
 		protocol = efi_va_arg(argptr, efi_guid_t*);
 		if (!protocol)
@@ -2628,104 +2624,212 @@ efi_status_t EFIAPI efi_install_multiple_protocol_interfaces
 		if (!guidcmp(protocol, &efi_guid_device_path)) {
 			struct efi_device_path *dp = protocol_interface;
 
-			r = EFI_CALL(efi_locate_device_path(protocol, &dp,
-							    &old_handle));
-			if (r == EFI_SUCCESS &&
+			ret = EFI_CALL(efi_locate_device_path(protocol, &dp,
+							      &old_handle));
+			if (ret == EFI_SUCCESS &&
 			    dp->type == DEVICE_PATH_TYPE_END) {
 				EFI_PRINT("Path %pD already installed\n",
 					  protocol_interface);
-				r = EFI_ALREADY_STARTED;
+				ret = EFI_ALREADY_STARTED;
 				break;
 			}
 		}
-		r = EFI_CALL(efi_install_protocol_interface(
-						handle, protocol,
-						EFI_NATIVE_INTERFACE,
-						protocol_interface));
-		if (r != EFI_SUCCESS)
+		ret = EFI_CALL(efi_install_protocol_interface(handle, protocol,
+							      EFI_NATIVE_INTERFACE,
+							      protocol_interface));
+		if (ret != EFI_SUCCESS)
 			break;
 		i++;
 	}
-	efi_va_end(argptr);
-	if (r == EFI_SUCCESS)
-		return EFI_EXIT(r);
+	if (ret == EFI_SUCCESS)
+		goto out;
 
 	/* If an error occurred undo all changes. */
-	efi_va_start(argptr, handle);
 	for (; i; --i) {
-		protocol = efi_va_arg(argptr, efi_guid_t*);
-		protocol_interface = efi_va_arg(argptr, void*);
+		protocol = efi_va_arg(argptr_copy, efi_guid_t*);
+		protocol_interface = efi_va_arg(argptr_copy, void*);
 		EFI_CALL(efi_uninstall_protocol_interface(*handle, protocol,
 							  protocol_interface));
 	}
-	efi_va_end(argptr);
 
-	return EFI_EXIT(r);
+out:
+	efi_va_end(argptr_copy);
+	return ret;
+
 }
 
 /**
- * efi_uninstall_multiple_protocol_interfaces() - uninstall multiple protocol
- *                                                interfaces
- * @handle: handle from which the protocol interfaces shall be removed
+ * efi_install_multiple_protocol_interfaces() - Install multiple protocol
+ *                                              interfaces
+ * @handle: handle on which the protocol interfaces shall be installed
  * @...:    NULL terminated argument list with pairs of protocol GUIDS and
  *          interfaces
  *
- * This function implements the UninstallMultipleProtocolInterfaces service.
+ *
+ * This is the function for internal usage in U-Boot. For the API function
+ * implementing the InstallMultipleProtocol service see
+ * efi_install_multiple_protocol_interfaces_ext()
+ *
+ * Return: status code
+ */
+efi_status_t EFIAPI
+efi_install_multiple_protocol_interfaces(efi_handle_t *handle, ...)
+{
+	efi_status_t ret;
+	efi_va_list argptr;
+
+	efi_va_start(argptr, handle);
+	ret = efi_install_multiple_protocol_interfaces_int(handle, argptr);
+	efi_va_end(argptr);
+	return ret;
+}
+
+/**
+ * efi_install_multiple_protocol_interfaces_ext() - Install multiple protocol
+ *                                                  interfaces
+ * @handle: handle on which the protocol interfaces shall be installed
+ * @...:    NULL terminated argument list with pairs of protocol GUIDS and
+ *          interfaces
+ *
+ * This function implements the MultipleProtocolInterfaces service.
  *
  * See the Unified Extensible Firmware Interface (UEFI) specification for
  * details.
  *
  * Return: status code
  */
-static efi_status_t EFIAPI efi_uninstall_multiple_protocol_interfaces(
-			efi_handle_t handle, ...)
+static efi_status_t EFIAPI
+efi_install_multiple_protocol_interfaces_ext(efi_handle_t *handle, ...)
 {
 	EFI_ENTRY("%p", handle);
-
+	efi_status_t ret;
 	efi_va_list argptr;
+
+	efi_va_start(argptr, handle);
+	ret = efi_install_multiple_protocol_interfaces_int(handle, argptr);
+	efi_va_end(argptr);
+	return EFI_EXIT(ret);
+}
+
+/**
+ * efi_uninstall_multiple_protocol_interfaces_int() - wrapper for uninstall
+ *                                                  multiple protocol
+ *                                                  interfaces
+ * @handle: handle from which the protocol interfaces shall be removed
+ * @argptr: va_list of args
+ *
+ * Core functionality of efi_uninstall_multiple_protocol_interfaces
+ * Must not be called directly
+ *
+ * Return: status code
+ */
+static efi_status_t EFIAPI
+efi_uninstall_multiple_protocol_interfaces_int(efi_handle_t handle,
+					       efi_va_list argptr)
+{
 	const efi_guid_t *protocol;
 	void *protocol_interface;
-	efi_status_t r = EFI_SUCCESS;
+	efi_status_t ret;
 	size_t i = 0;
+	efi_va_list argptr_copy;
 
 	if (!handle)
-		return EFI_EXIT(EFI_INVALID_PARAMETER);
+		return EFI_INVALID_PARAMETER;
 
-	efi_va_start(argptr, handle);
+	efi_va_copy(argptr_copy, argptr);
 	for (;;) {
 		protocol = efi_va_arg(argptr, efi_guid_t*);
 		if (!protocol)
 			break;
 		protocol_interface = efi_va_arg(argptr, void*);
-		r = efi_uninstall_protocol(handle, protocol,
-					   protocol_interface);
-		if (r != EFI_SUCCESS)
+		ret = efi_uninstall_protocol(handle, protocol,
+					     protocol_interface);
+		if (ret != EFI_SUCCESS)
 			break;
 		i++;
 	}
-	efi_va_end(argptr);
-	if (r == EFI_SUCCESS) {
+	if (ret == EFI_SUCCESS) {
 		/* If the last protocol has been removed, delete the handle. */
 		if (list_empty(&handle->protocols)) {
 			list_del(&handle->link);
 			free(handle);
 		}
-		return EFI_EXIT(r);
+		goto out;
 	}
 
 	/* If an error occurred undo all changes. */
-	efi_va_start(argptr, handle);
 	for (; i; --i) {
-		protocol = efi_va_arg(argptr, efi_guid_t*);
-		protocol_interface = efi_va_arg(argptr, void*);
+		protocol = efi_va_arg(argptr_copy, efi_guid_t*);
+		protocol_interface = efi_va_arg(argptr_copy, void*);
 		EFI_CALL(efi_install_protocol_interface(&handle, protocol,
 							EFI_NATIVE_INTERFACE,
 							protocol_interface));
 	}
+	/*
+	 * If any errors are generated while the protocol interfaces are being
+	 * uninstalled, then the protocols uninstalled prior to the error will
+	 * be reinstalled using InstallProtocolInterface() and the status code
+	 * EFI_INVALID_PARAMETER is returned.
+	 */
+	ret = EFI_INVALID_PARAMETER;
+
+out:
+	efi_va_end(argptr_copy);
+	return ret;
+}
+
+/**
+ * efi_uninstall_multiple_protocol_interfaces() - uninstall multiple protocol
+ *                                                interfaces
+ * @handle: handle from which the protocol interfaces shall be removed
+ * @...:    NULL terminated argument list with pairs of protocol GUIDS and
+ *          interfaces
+ *
+ * This function implements the UninstallMultipleProtocolInterfaces service.
+ *
+ * This is the function for internal usage in U-Boot. For the API function
+ * implementing the UninstallMultipleProtocolInterfaces service see
+ * efi_uninstall_multiple_protocol_interfaces_ext()
+ *
+ * Return: status code
+ */
+efi_status_t EFIAPI
+efi_uninstall_multiple_protocol_interfaces(efi_handle_t handle, ...)
+{
+	efi_status_t ret;
+	efi_va_list argptr;
+
+	efi_va_start(argptr, handle);
+	ret = efi_uninstall_multiple_protocol_interfaces_int(handle, argptr);
 	efi_va_end(argptr);
+	return ret;
+}
+
+/**
+ * efi_uninstall_multiple_protocol_interfaces_ext() - uninstall multiple protocol
+ *                                                    interfaces
+ * @handle: handle from which the protocol interfaces shall be removed
+ * @...:    NULL terminated argument list with pairs of protocol GUIDS and
+ *          interfaces
+ *
+ * This function implements the UninstallMultipleProtocolInterfaces service.
+ *
+ * See the Unified Extensible Firmware Interface (UEFI) specification for
+ * details.
+ *
+ * Return: status code
+ */
+static efi_status_t EFIAPI
+efi_uninstall_multiple_protocol_interfaces_ext(efi_handle_t handle, ...)
+{
+	EFI_ENTRY("%p", handle);
+	efi_status_t ret;
+	efi_va_list argptr;
 
-	/* In case of an error always return EFI_INVALID_PARAMETER */
-	return EFI_EXIT(EFI_INVALID_PARAMETER);
+	efi_va_start(argptr, handle);
+	ret = efi_uninstall_multiple_protocol_interfaces_int(handle, argptr);
+	efi_va_end(argptr);
+	return EFI_EXIT(ret);
 }
 
 /**
@@ -3785,9 +3889,9 @@ static struct efi_boot_services efi_boot_services = {
 	.locate_handle_buffer = efi_locate_handle_buffer,
 	.locate_protocol = efi_locate_protocol,
 	.install_multiple_protocol_interfaces =
-			efi_install_multiple_protocol_interfaces,
+			efi_install_multiple_protocol_interfaces_ext,
 	.uninstall_multiple_protocol_interfaces =
-			efi_uninstall_multiple_protocol_interfaces,
+			efi_uninstall_multiple_protocol_interfaces_ext,
 	.calculate_crc32 = efi_calculate_crc32,
 	.copy_mem = efi_copy_mem,
 	.set_mem = efi_set_mem,
diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
index a6b98f066a0..b6bd2d6af88 100644
--- a/lib/efi_loader/efi_capsule.c
+++ b/lib/efi_loader/efi_capsule.c
@@ -636,17 +636,18 @@ efi_status_t __weak efi_load_capsule_drivers(void)
 
 	if (IS_ENABLED(CONFIG_EFI_CAPSULE_FIRMWARE_FIT)) {
 		handle = NULL;
-		ret = EFI_CALL(efi_install_multiple_protocol_interfaces(
-				&handle, &efi_guid_firmware_management_protocol,
-				&efi_fmp_fit, NULL));
+		ret = efi_install_multiple_protocol_interfaces(&handle,
+							       &efi_guid_firmware_management_protocol,
+							       &efi_fmp_fit,
+							       NULL);
 	}
 
 	if (IS_ENABLED(CONFIG_EFI_CAPSULE_FIRMWARE_RAW)) {
 		handle = NULL;
-		ret = EFI_CALL(efi_install_multiple_protocol_interfaces(
-				&handle,
-				&efi_guid_firmware_management_protocol,
-				&efi_fmp_raw, NULL));
+		ret = efi_install_multiple_protocol_interfaces(&handle,
+							       &efi_guid_firmware_management_protocol,
+							       &efi_fmp_raw,
+							       NULL);
 	}
 
 	return ret;
diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
index cf9fbd9cb54..3354b217a9a 100644
--- a/lib/efi_loader/efi_console.c
+++ b/lib/efi_loader/efi_console.c
@@ -1278,12 +1278,14 @@ efi_status_t efi_console_register(void)
 	struct efi_device_path *dp;
 
 	/* Install protocols on root node */
-	r = EFI_CALL(efi_install_multiple_protocol_interfaces
-		     (&efi_root,
-		      &efi_guid_text_output_protocol, &efi_con_out,
-		      &efi_guid_text_input_protocol, &efi_con_in,
-		      &efi_guid_text_input_ex_protocol, &efi_con_in_ex,
-		      NULL));
+	r = efi_install_multiple_protocol_interfaces(&efi_root,
+						     &efi_guid_text_output_protocol,
+						     &efi_con_out,
+						     &efi_guid_text_input_protocol,
+						     &efi_con_in,
+						     &efi_guid_text_input_ex_protocol,
+						     &efi_con_in_ex,
+						     NULL);
 
 	/* Create console node and install device path protocols */
 	if (CONFIG_IS_ENABLED(DM_SERIAL)) {
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index ebffb771228..acae007f26f 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -936,7 +936,8 @@ struct efi_device_path *efi_dp_part_node(struct blk_desc *desc, int part)
 		dpsize = sizeof(struct efi_device_path_hard_drive_path);
 	buf = dp_alloc(dpsize);
 
-	dp_part_node(buf, desc, part);
+	if (buf)
+		dp_part_node(buf, desc, part);
 
 	return buf;
 }
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 39ea1a68a68..e6a356b5897 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -415,6 +415,11 @@ static efi_status_t efi_disk_add_dev(
 		struct efi_handler *handler;
 		void *protocol_interface;
 
+		if (!node) {
+			ret = EFI_OUT_OF_RESOURCES;
+			goto error;
+		}
+
 		/* Parent must expose EFI_BLOCK_IO_PROTOCOL */
 		ret = efi_search_protocol(parent, &efi_block_io_guid, &handler);
 		if (ret != EFI_SUCCESS)
@@ -449,10 +454,12 @@ static efi_status_t efi_disk_add_dev(
 	 * in this case.
 	 */
 	handle = &diskobj->header;
-	ret = EFI_CALL(efi_install_multiple_protocol_interfaces(
-			&handle, &efi_guid_device_path, diskobj->dp,
-			&efi_block_io_guid, &diskobj->ops,
-			guid, NULL, NULL));
+	ret = efi_install_multiple_protocol_interfaces(&handle,
+						       &efi_guid_device_path,
+						       diskobj->dp,
+						       &efi_block_io_guid,
+						       &diskobj->ops, guid,
+						       NULL, NULL);
 	if (ret != EFI_SUCCESS)
 		goto error;
 
@@ -620,7 +627,7 @@ static int efi_disk_create_part(struct udevice *dev)
  *
  * @return	0 on success, -1 otherwise
  */
-static int efi_disk_probe(void *ctx, struct event *event)
+int efi_disk_probe(void *ctx, struct event *event)
 {
 	struct udevice *dev;
 	enum uclass_id id;
@@ -724,7 +731,7 @@ static int efi_disk_delete_part(struct udevice *dev)
  *
  * @return	0 on success, -1 otherwise
  */
-static int efi_disk_remove(void *ctx, struct event *event)
+int efi_disk_remove(void *ctx, struct event *event)
 {
 	enum uclass_id id;
 	struct udevice *dev;
@@ -740,27 +747,6 @@ static int efi_disk_remove(void *ctx, struct event *event)
 		return 0;
 }
 
-efi_status_t efi_disk_init(void)
-{
-	int ret;
-
-	ret = event_register("efi_disk add", EVT_DM_POST_PROBE,
-			     efi_disk_probe, NULL);
-	if (ret) {
-		log_err("Event registration for efi_disk add failed\n");
-		return EFI_OUT_OF_RESOURCES;
-	}
-
-	ret = event_register("efi_disk del", EVT_DM_PRE_REMOVE,
-			     efi_disk_remove, NULL);
-	if (ret) {
-		log_err("Event registration for efi_disk del failed\n");
-		return EFI_OUT_OF_RESOURCES;
-	}
-
-	return EFI_SUCCESS;
-}
-
 /**
  * efi_disk_get_device_name() - get U-Boot device name associated with EFI handle
  *
diff --git a/lib/efi_loader/efi_helper.c b/lib/efi_loader/efi_helper.c
index 8ed564e2619..c71e87d1180 100644
--- a/lib/efi_loader/efi_helper.c
+++ b/lib/efi_loader/efi_helper.c
@@ -171,3 +171,22 @@ int efi_link_dev(efi_handle_t handle, struct udevice *dev)
 	handle->dev = dev;
 	return dev_tag_set_ptr(dev, DM_TAG_EFI, handle);
 }
+
+/**
+ * efi_unlink_dev() - unlink udevice and handle
+ *
+ * @handle:	EFI handle to unlink
+ *
+ * Return:	0 on success, negative on failure
+ */
+int efi_unlink_dev(efi_handle_t handle)
+{
+	int ret;
+
+	ret = dev_tag_del(handle->dev, DM_TAG_EFI);
+	if (ret)
+		return ret;
+	handle->dev = NULL;
+
+	return 0;
+}
diff --git a/lib/efi_loader/efi_load_initrd.c b/lib/efi_loader/efi_load_initrd.c
index 3d6044f7604..87fde3f88c2 100644
--- a/lib/efi_loader/efi_load_initrd.c
+++ b/lib/efi_loader/efi_load_initrd.c
@@ -208,14 +208,13 @@ efi_status_t efi_initrd_register(void)
 	if (ret != EFI_SUCCESS)
 		return ret;
 
-	ret = EFI_CALL(efi_install_multiple_protocol_interfaces
-		       (&efi_initrd_handle,
-			/* initramfs */
-			&efi_guid_device_path, &dp_lf2_handle,
-			/* LOAD_FILE2 */
-			&efi_guid_load_file2_protocol,
-			(void *)&efi_lf2_protocol,
-			NULL));
+	ret = efi_install_multiple_protocol_interfaces(&efi_initrd_handle,
+						       /* initramfs */
+						       &efi_guid_device_path, &dp_lf2_handle,
+						       /* LOAD_FILE2 */
+						       &efi_guid_load_file2_protocol,
+						       (void *)&efi_lf2_protocol,
+						       NULL);
 
 	return ret;
 }
diff --git a/lib/efi_loader/efi_root_node.c b/lib/efi_loader/efi_root_node.c
index 739c6867f41..a4eb6f493dc 100644
--- a/lib/efi_loader/efi_root_node.c
+++ b/lib/efi_loader/efi_root_node.c
@@ -49,38 +49,38 @@ efi_status_t efi_root_node_register(void)
 	dp->end.length = sizeof(struct efi_device_path);
 
 	/* Create root node and install protocols */
-	ret = EFI_CALL(efi_install_multiple_protocol_interfaces
-			(&efi_root,
-			 /* Device path protocol */
-			 &efi_guid_device_path, dp,
+	ret = efi_install_multiple_protocol_interfaces
+		(&efi_root,
+		 /* Device path protocol */
+		 &efi_guid_device_path, dp,
 #if CONFIG_IS_ENABLED(EFI_DEVICE_PATH_TO_TEXT)
-			 /* Device path to text protocol */
-			 &efi_guid_device_path_to_text_protocol,
-			 (void *)&efi_device_path_to_text,
+		 /* Device path to text protocol */
+		 &efi_guid_device_path_to_text_protocol,
+		 &efi_device_path_to_text,
 #endif
-#ifdef CONFIG_EFI_DEVICE_PATH_UTIL
-			 /* Device path utilities protocol */
-			 &efi_guid_device_path_utilities_protocol,
-			 (void *)&efi_device_path_utilities,
+#if CONFIG_IS_ENABLED(EFI_DEVICE_PATH_UTIL)
+		 /* Device path utilities protocol */
+		 &efi_guid_device_path_utilities_protocol,
+		 &efi_device_path_utilities,
 #endif
-#ifdef CONFIG_EFI_DT_FIXUP
-			 /* Device-tree fix-up protocol */
-			 &efi_guid_dt_fixup_protocol,
-			 (void *)&efi_dt_fixup_prot,
+#if CONFIG_IS_ENABLED(EFI_DT_FIXUP)
+		 /* Device-tree fix-up protocol */
+		 &efi_guid_dt_fixup_protocol,
+		 &efi_dt_fixup_prot,
 #endif
 #if CONFIG_IS_ENABLED(EFI_UNICODE_COLLATION_PROTOCOL2)
-			 &efi_guid_unicode_collation_protocol2,
-			 (void *)&efi_unicode_collation_protocol2,
+		 &efi_guid_unicode_collation_protocol2,
+		 &efi_unicode_collation_protocol2,
 #endif
 #if CONFIG_IS_ENABLED(EFI_LOADER_HII)
-			 /* HII string protocol */
-			 &efi_guid_hii_string_protocol,
-			 (void *)&efi_hii_string,
-			 /* HII database protocol */
-			 &efi_guid_hii_database_protocol,
-			 (void *)&efi_hii_database,
+		 /* HII string protocol */
+		 &efi_guid_hii_string_protocol,
+		 &efi_hii_string,
+		 /* HII database protocol */
+		 &efi_guid_hii_database_protocol,
+		 &efi_hii_database,
 #endif
-			 NULL));
+		 NULL);
 	efi_root->type = EFI_OBJECT_TYPE_U_BOOT_FIRMWARE;
 	return ret;
 }
diff --git a/lib/efi_loader/efi_setup.c b/lib/efi_loader/efi_setup.c
index c633fcd91e3..9d7189336dc 100644
--- a/lib/efi_loader/efi_setup.c
+++ b/lib/efi_loader/efi_setup.c
@@ -198,7 +198,8 @@ static efi_status_t __efi_init_early(void)
 	if (ret != EFI_SUCCESS)
 		goto out;
 
-	ret = efi_disk_init();
+	/* Initialize EFI driver uclass */
+	ret = efi_driver_init();
 out:
 	return ret;
 }
@@ -319,11 +320,6 @@ efi_status_t efi_init_obj_list(void)
 	if (ret != EFI_SUCCESS)
 		goto out;
 
-	/* Initialize EFI driver uclass */
-	ret = efi_driver_init();
-	if (ret != EFI_SUCCESS)
-		goto out;
-
 	if (IS_ENABLED(CONFIG_EFI_HAVE_CAPSULE_SUPPORT)) {
 		ret = efi_load_capsule_drivers();
 		if (ret != EFI_SUCCESS)
diff --git a/lib/efi_loader/efi_string.c b/lib/efi_loader/efi_string.c
index 8bf1e493b89..e21e09c9461 100644
--- a/lib/efi_loader/efi_string.c
+++ b/lib/efi_loader/efi_string.c
@@ -8,6 +8,7 @@
 #include <common.h>
 #include <charset.h>
 #include <efi_loader.h>
+#include <malloc.h>
 
 /**
  * efi_create_indexed_name - create a string name with an index
@@ -41,3 +42,26 @@ u16 *efi_create_indexed_name(u16 *buffer, size_t buffer_size, const char *name,
 
 	return p;
 }
+
+/**
+ * efi_convert_string - Convert an ASCII or UTF-8 string to UTF-16
+ * @str:	String to be converted
+ *
+ * Return: Converted string in UTF-16 format. The caller is responsible for
+ *         freeing this string when it is no longer needed.
+ */
+efi_string_t efi_convert_string(const char *str)
+{
+	efi_string_t str_16, tmp;
+	size_t sz_16;
+
+	sz_16 = utf8_utf16_strlen(str);
+	str_16 = calloc(sz_16 + 1, sizeof(u16));
+	if (!str_16)
+		return NULL;
+
+	tmp = str_16;
+	utf8_utf16_strcpy(&tmp, str);
+
+	return str_16;
+}