2 Provide Boot Manager related library APIs.
4 Copyright (c) 2011 - 2019, Intel Corporation. All rights reserved.<BR>
5 (C) Copyright 2015-2016 Hewlett Packard Enterprise Development LP<BR>
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution. The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
17 #ifndef _UEFI_BOOT_MANAGER_LIB_H_
18 #define _UEFI_BOOT_MANAGER_LIB_H_
20 #include <Protocol/DriverHealth.h>
21 #include <Library/SortLib.h>
24 // Boot Manager load option library functions.
32 LoadOptionTypeSysPrep
,
34 LoadOptionTypePlatformRecovery
,
36 } EFI_BOOT_MANAGER_LOAD_OPTION_TYPE
;
39 LoadOptionNumberMax
= 0x10000,
40 LoadOptionNumberUnassigned
= LoadOptionNumberMax
41 } EFI_BOOT_MANAGER_LOAD_OPTION_NUMBER
;
44 // Common structure definition for DriverOption and BootOption
48 // Data read from UEFI NV variables
50 UINTN OptionNumber
; // #### numerical value, could be LoadOptionNumberUnassigned
51 EFI_BOOT_MANAGER_LOAD_OPTION_TYPE OptionType
; // LoadOptionTypeBoot or LoadOptionTypeDriver
52 UINT32 Attributes
; // Load Option Attributes
53 CHAR16
*Description
; // Load Option Description
54 EFI_DEVICE_PATH_PROTOCOL
*FilePath
; // Load Option Device Path
55 UINT8
*OptionalData
; // Load Option optional data to pass into image
56 UINT32 OptionalDataSize
; // Load Option size of OptionalData
62 EFI_STATUS Status
; // Status returned from boot attempt gBS->StartImage ()
63 CHAR16
*ExitData
; // Exit data returned from gBS->StartImage ()
64 UINTN ExitDataSize
; // Size of ExitData
65 } EFI_BOOT_MANAGER_LOAD_OPTION
;
68 Returns an array of load options based on the EFI variable
69 L"BootOrder"/L"DriverOrder" and the L"Boot####"/L"Driver####" variables impled by it.
70 #### is the hex value of the UINT16 in each BootOrder/DriverOrder entry.
72 @param LoadOptionCount Returns number of entries in the array.
73 @param LoadOptionType The type of the load option.
75 @retval NULL No load options exist.
76 @retval !NULL Array of load option entries.
79 EFI_BOOT_MANAGER_LOAD_OPTION
*
81 EfiBootManagerGetLoadOptions (
82 OUT UINTN
*LoadOptionCount
,
83 IN EFI_BOOT_MANAGER_LOAD_OPTION_TYPE LoadOptionType
87 Free an array of load options returned from EfiBootManagerGetLoadOptions().
89 @param LoadOptions Pointer to the array of load options to free.
90 @param LoadOptionCount Number of array entries in LoadOptions.
92 @return EFI_SUCCESS LoadOptions was freed.
93 @return EFI_INVALID_PARAMETER LoadOptions is NULL.
97 EfiBootManagerFreeLoadOptions (
98 IN EFI_BOOT_MANAGER_LOAD_OPTION
*LoadOptions
,
99 IN UINTN LoadOptionCount
103 Initialize a load option.
105 @param Option Pointer to the load option to be initialized.
106 @param OptionNumber Option number of the load option.
107 @param OptionType Type of the load option.
108 @param Attributes Attributes of the load option.
109 @param Description Description of the load option.
110 @param FilePath Device path of the load option.
111 @param OptionalData Optional data of the load option.
112 @param OptionalDataSize Size of the optional data of the load option.
114 @retval EFI_SUCCESS The load option was initialized successfully.
115 @retval EFI_INVALID_PARAMETER Option, Description or FilePath is NULL.
119 EfiBootManagerInitializeLoadOption (
120 IN OUT EFI_BOOT_MANAGER_LOAD_OPTION
*Option
,
121 IN UINTN OptionNumber
,
122 IN EFI_BOOT_MANAGER_LOAD_OPTION_TYPE OptionType
,
123 IN UINT32 Attributes
,
124 IN CHAR16
*Description
,
125 IN EFI_DEVICE_PATH_PROTOCOL
*FilePath
,
126 IN UINT8
*OptionalData
,
127 IN UINT32 OptionalDataSize
131 Free a load option created by EfiBootManagerInitializeLoadOption()
132 or EfiBootManagerVariableToLoadOption().
134 @param LoadOption Pointer to the load option to free.
135 CONCERN: Check Boot#### instead of BootOrder, optimize, spec clarify
136 @return EFI_SUCCESS LoadOption was freed.
137 @return EFI_INVALID_PARAMETER LoadOption is NULL.
142 EfiBootManagerFreeLoadOption (
143 IN EFI_BOOT_MANAGER_LOAD_OPTION
*LoadOption
147 Initialize the load option from the VariableName.
149 @param VariableName EFI Variable name which could be Boot#### or
151 @param LoadOption Pointer to the load option to be initialized
153 @retval EFI_SUCCESS The option was created
154 @retval EFI_INVALID_PARAMETER VariableName or LoadOption is NULL.
155 @retval EFI_NOT_FOUND The variable specified by VariableName cannot be found.
159 EfiBootManagerVariableToLoadOption (
160 IN CHAR16
*VariableName
,
161 IN OUT EFI_BOOT_MANAGER_LOAD_OPTION
*LoadOption
165 Create the Boot#### or Driver#### variable from the load option.
167 @param LoadOption Pointer to the load option.
169 @retval EFI_SUCCESS The variable was created.
170 @retval Others Error status returned by RT->SetVariable.
174 EfiBootManagerLoadOptionToVariable (
175 IN CONST EFI_BOOT_MANAGER_LOAD_OPTION
*LoadOption
179 This function will register the new Boot####, Driver#### or SysPrep#### option.
180 After the *#### is updated, the *Order will also be updated.
182 @param Option Pointer to load option to add. If on input
183 Option->OptionNumber is LoadOptionNumberUnassigned,
184 then on output Option->OptionNumber is updated to
185 the number of the new Boot####,
186 Driver#### or SysPrep#### option.
187 @param Position Position of the new load option to put in the ****Order variable.
189 @retval EFI_SUCCESS The *#### have been successfully registered.
190 @retval EFI_INVALID_PARAMETER The option number exceeds 0xFFFF.
191 @retval EFI_ALREADY_STARTED The option number of Option is being used already.
192 Note: this API only adds new load option, no replacement support.
193 @retval EFI_OUT_OF_RESOURCES There is no free option number that can be used when the
194 option number specified in the Option is LoadOptionNumberUnassigned.
195 @return Status codes of gRT->SetVariable ().
200 EfiBootManagerAddLoadOptionVariable (
201 IN OUT EFI_BOOT_MANAGER_LOAD_OPTION
*Option
,
206 Delete the load option according to the OptionNumber and OptionType.
208 Only the BootOrder/DriverOrder is updated to remove the reference of the OptionNumber.
210 @param OptionNumber Option number of the load option.
211 @param OptionType Type of the load option.
213 @retval EFI_NOT_FOUND The load option cannot be found.
214 @retval EFI_SUCCESS The load option was deleted.
218 EfiBootManagerDeleteLoadOptionVariable (
219 IN UINTN OptionNumber
,
220 IN EFI_BOOT_MANAGER_LOAD_OPTION_TYPE OptionType
224 Sort the load options. The DriverOrder/BootOrder variables will be re-created to
225 reflect the new order.
227 @param OptionType The type of the load option.
228 @param CompareFunction The comparator function pointer.
232 EfiBootManagerSortLoadOptionVariable (
233 IN EFI_BOOT_MANAGER_LOAD_OPTION_TYPE OptionType
,
234 IN SORT_COMPARE CompareFunction
238 Return the index of the load option in the load option array.
240 The function consider two load options are equal when the
241 OptionType, Attributes, Description, FilePath and OptionalData are equal.
243 @param Key Pointer to the load option to be found.
244 @param Array Pointer to the array of load options to be found.
245 @param Count Number of entries in the Array.
247 @retval -1 Key wasn't found in the Array.
248 @retval 0 ~ Count-1 The index of the Key in the Array.
252 EfiBootManagerFindLoadOption (
253 IN CONST EFI_BOOT_MANAGER_LOAD_OPTION
*Key
,
254 IN CONST EFI_BOOT_MANAGER_LOAD_OPTION
*Array
,
259 // Boot Manager hot key library functions.
268 /// Specifies options about how the key will be processed.
270 EFI_BOOT_KEY_DATA KeyData
;
272 /// The CRC-32 which should match the CRC-32 of the entire EFI_LOAD_OPTION to
273 /// which BootOption refers. If the CRC-32s do not match this value, then this key
274 /// option is ignored.
276 UINT32 BootOptionCrc
;
278 /// The Boot#### option which will be invoked if this key is pressed and the boot option
279 /// is active (LOAD_OPTION_ACTIVE is set).
283 /// The key codes to compare against those returned by the
284 /// EFI_SIMPLE_TEXT_INPUT and EFI_SIMPLE_TEXT_INPUT_EX protocols.
285 /// The number of key codes (0-3) is specified by the EFI_KEY_CODE_COUNT field in KeyOptions.
287 EFI_INPUT_KEY Keys
[3];
289 } EFI_BOOT_MANAGER_KEY_OPTION
;
293 Start the hot key service so that the key press can trigger the boot option.
295 @param HotkeyTriggered Return the waitable event and it will be signaled
296 when a valid hot key is pressed.
298 @retval EFI_SUCCESS The hot key service is started.
302 EfiBootManagerStartHotkeyService (
303 IN EFI_EVENT
*HotkeyTriggered
307 // Modifier for EfiBootManagerAddKeyOptionVariable and EfiBootManagerDeleteKeyOptionVariable
309 #define EFI_BOOT_MANAGER_SHIFT_PRESSED 0x00000001
310 #define EFI_BOOT_MANAGER_CONTROL_PRESSED 0x00000002
311 #define EFI_BOOT_MANAGER_ALT_PRESSED 0x00000004
312 #define EFI_BOOT_MANAGER_LOGO_PRESSED 0x00000008
313 #define EFI_BOOT_MANAGER_MENU_KEY_PRESSED 0x00000010
314 #define EFI_BOOT_MANAGER_SYS_REQ_PRESSED 0x00000020
318 It adds the key option variable and the key option takes affect immediately.
320 @param AddedOption Return the added key option.
321 @param BootOptionNumber The boot option number for the key option.
322 @param Modifier Key shift state.
323 @param ... Parameter list of pointer of EFI_INPUT_KEY.
325 @retval EFI_SUCCESS The key option is added.
326 @retval EFI_ALREADY_STARTED The hot key is already used by certain key option.
330 EfiBootManagerAddKeyOptionVariable (
331 OUT EFI_BOOT_MANAGER_KEY_OPTION
*AddedOption
, OPTIONAL
332 IN UINT16 BootOptionNumber
,
338 Delete the Key Option variable and unregister the hot key
340 @param DeletedOption Return the deleted key options.
341 @param Modifier Key shift state.
342 @param ... Parameter list of pointer of EFI_INPUT_KEY.
344 @retval EFI_SUCCESS The key option is deleted.
345 @retval EFI_NOT_FOUND The key option cannot be found.
349 EfiBootManagerDeleteKeyOptionVariable (
350 IN EFI_BOOT_MANAGER_KEY_OPTION
*DeletedOption
, OPTIONAL
356 Register the key option to exit the waiting of the Boot Manager timeout.
357 Platform should ensure that the continue key option isn't conflict with
358 other boot key options.
360 @param Modifier Key shift state.
361 @param ... Parameter list of pointer of EFI_INPUT_KEY.
363 @retval EFI_SUCCESS Successfully register the continue key option.
364 @retval EFI_ALREADY_STARTED The continue key option is already registered.
368 EfiBootManagerRegisterContinueKeyOption (
374 Try to boot the boot option triggered by hot key.
378 EfiBootManagerHotkeyBoot (
382 // Boot Manager boot library functions.
386 The function creates boot options for all possible bootable medias in the following order:
387 1. Removable BlockIo - The boot option only points to the removable media
388 device, like USB key, DVD, Floppy etc.
389 2. Fixed BlockIo - The boot option only points to a Fixed blockIo device,
391 3. Non-BlockIo SimpleFileSystem - The boot option points to a device supporting
392 SimpleFileSystem Protocol, but not supporting BlockIo
394 4. LoadFile - The boot option points to the media supporting
396 Reference: UEFI Spec chapter 3.3 Boot Option Variables Default Boot Behavior
398 The function won't delete the boot option not added by itself.
402 EfiBootManagerRefreshAllBootOption (
407 Attempt to boot the EFI boot option. This routine sets L"BootCurent" and
408 signals the EFI ready to boot event. If the device path for the option starts
409 with a BBS device path a legacy boot is attempted. Short form device paths are
410 also supported via this rountine. A device path starting with
411 MEDIA_HARDDRIVE_DP, MSG_USB_WWID_DP, MSG_USB_CLASS_DP gets expaned out
412 to find the first device that matches. If the BootOption Device Path
413 fails the removable media boot algorithm is attempted (\EFI\BOOTIA32.EFI,
414 \EFI\BOOTX64.EFI,... only one file type is tried per processor type)
416 @param BootOption Boot Option to try and boot.
417 On return, BootOption->Status contains the boot status:
418 EFI_SUCCESS BootOption was booted
419 EFI_UNSUPPORTED BootOption isn't supported.
420 EFI_NOT_FOUND The BootOption was not found on the system
421 Others BootOption failed with this error status
427 IN EFI_BOOT_MANAGER_LOAD_OPTION
*BootOption
431 Return the boot option corresponding to the Boot Manager Menu.
432 It may automatically create one if the boot option hasn't been created yet.
434 @param BootOption Return the Boot Manager Menu.
436 @retval EFI_SUCCESS The Boot Manager Menu is successfully returned.
437 @retval EFI_NOT_FOUND The Boot Manager Menu cannot be found.
438 @retval others Return status of gRT->SetVariable (). BootOption still points
439 to the Boot Manager Menu even the Status is not EFI_SUCCESS
444 EfiBootManagerGetBootManagerMenu (
445 EFI_BOOT_MANAGER_LOAD_OPTION
*BootOption
449 Get the next possible full path pointing to the load option.
450 The routine doesn't guarantee the returned full path points to an existing
451 file, and it also doesn't guarantee the existing file is a valid load option.
452 BmGetNextLoadOptionBuffer() guarantees.
454 @param FilePath The device path pointing to a load option.
455 It could be a short-form device path.
456 @param FullPath The full path returned by the routine in last call.
457 Set to NULL in first call.
459 @return The next possible full path pointing to the load option.
460 Caller is responsible to free the memory.
462 EFI_DEVICE_PATH_PROTOCOL
*
463 EfiBootManagerGetNextFullDevicePath (
464 IN EFI_DEVICE_PATH_PROTOCOL
*FilePath
,
465 IN EFI_DEVICE_PATH_PROTOCOL
*FullPath
469 Get the load option by its device path.
471 @param FilePath The device path pointing to a load option.
472 It could be a short-form device path.
473 @param FullPath Return the full device path of the load option after
474 short-form device path expanding.
475 Caller is responsible to free it.
476 @param FileSize Return the load option size.
478 @return The load option buffer. Caller is responsible to free the memory.
482 EfiBootManagerGetLoadOptionBuffer (
483 IN EFI_DEVICE_PATH_PROTOCOL
*FilePath
,
484 OUT EFI_DEVICE_PATH_PROTOCOL
**FullPath
,
489 The function enumerates all the legacy boot options, creates them and
490 registers them in the BootOrder variable.
494 (EFIAPI
*EFI_BOOT_MANAGER_REFRESH_LEGACY_BOOT_OPTION
) (
499 The function boots a legacy boot option.
503 (EFIAPI
*EFI_BOOT_MANAGER_LEGACY_BOOT
) (
504 IN EFI_BOOT_MANAGER_LOAD_OPTION
*BootOption
508 The function registers the legacy boot support capabilities.
510 @param RefreshLegacyBootOption The function pointer to create all the legacy boot options.
511 @param LegacyBoot The function pointer to boot the legacy boot option.
515 EfiBootManagerRegisterLegacyBootSupport (
516 EFI_BOOT_MANAGER_REFRESH_LEGACY_BOOT_OPTION RefreshLegacyBootOption
,
517 EFI_BOOT_MANAGER_LEGACY_BOOT LegacyBoot
521 Return the platform provided boot option description for the controller.
523 @param Handle Controller handle.
524 @param DefaultDescription Default boot description provided by core.
526 @return The callee allocated description string
527 or NULL if the handler wants to use DefaultDescription.
531 (EFIAPI
*EFI_BOOT_MANAGER_BOOT_DESCRIPTION_HANDLER
) (
532 IN EFI_HANDLE Handle
,
533 IN CONST CHAR16
*DefaultDescription
537 Register the platform provided boot description handler.
539 @param Handler The platform provided boot description handler
541 @retval EFI_SUCCESS The handler was registered successfully.
542 @retval EFI_ALREADY_STARTED The handler was already registered.
543 @retval EFI_OUT_OF_RESOURCES There is not enough resource to perform the registration.
547 EfiBootManagerRegisterBootDescriptionHandler (
548 IN EFI_BOOT_MANAGER_BOOT_DESCRIPTION_HANDLER Handler
552 // Boot Manager connect and disconnect library functions
556 This function will connect all the system driver to controller
557 first, and then special connect the default console, this make
558 sure all the system controller available and the platform default
563 EfiBootManagerConnectAll (
568 This function will create all handles associate with every device
569 path node. If the handle associate with one device path node can not
570 be created successfully, then still give chance to do the dispatch,
571 which load the missing drivers if possible.
573 @param DevicePathToConnect The device path which will be connected, it can be
574 a multi-instance device path
575 @param MatchingHandle Return the controller handle closest to the DevicePathToConnect
577 @retval EFI_SUCCESS All handles associate with every device path node
579 @retval EFI_OUT_OF_RESOURCES There is no resource to create new handles.
580 @retval EFI_NOT_FOUND Create the handle associate with one device path
582 @retval EFI_SECURITY_VIOLATION The user has no permission to start UEFI device
583 drivers on the DevicePath.
587 EfiBootManagerConnectDevicePath (
588 IN EFI_DEVICE_PATH_PROTOCOL
*DevicePathToConnect
,
589 OUT EFI_HANDLE
*MatchingHandle OPTIONAL
593 This function will disconnect all current system handles.
595 gBS->DisconnectController() is invoked for each handle exists in system handle buffer.
596 If handle is a bus type handle, all childrens also are disconnected recursively by
597 gBS->DisconnectController().
601 EfiBootManagerDisconnectAll (
607 // Boot Manager console library functions
621 This function will connect all the console devices base on the console
622 device variable ConIn, ConOut and ErrOut.
624 @retval EFI_DEVICE_ERROR All the consoles were not connected due to an error.
625 @retval EFI_SUCCESS Success connect any one instance of the console
626 device path base on the variable ConVarName.
630 EfiBootManagerConnectAllDefaultConsoles (
635 This function updates the console variable based on ConVarName. It can
636 add or remove one specific console device path from the variable
638 @param ConsoleType ConIn, ConOut, ErrOut, ConInDev, ConOutDev or ErrOutDev.
639 @param CustomizedConDevicePath The console device path to be added to
640 the console variable. Cannot be multi-instance.
641 @param ExclusiveDevicePath The console device path to be removed
642 from the console variable. Cannot be multi-instance.
644 @retval EFI_UNSUPPORTED The added device path is the same as a removed one.
645 @retval EFI_SUCCESS Successfully added or removed the device path from the
651 EfiBootManagerUpdateConsoleVariable (
652 IN CONSOLE_TYPE ConsoleType
,
653 IN EFI_DEVICE_PATH_PROTOCOL
*CustomizedConDevicePath
,
654 IN EFI_DEVICE_PATH_PROTOCOL
*ExclusiveDevicePath
658 Connect the console device base on the variable ConVarName, if
659 device path of the ConVarName is multi-instance device path, if
660 anyone of the instances is connected success, then this function
663 @param ConsoleType ConIn, ConOut or ErrOut.
665 @retval EFI_NOT_FOUND There is not any console devices connected
667 @retval EFI_SUCCESS Success connect any one instance of the console
668 device path base on the variable ConVarName.
673 EfiBootManagerConnectConsoleVariable (
674 IN CONSOLE_TYPE ConsoleType
678 Query all the children of VideoController and return the device paths of all the
679 children that support GraphicsOutput protocol.
681 @param VideoController PCI handle of video controller.
683 @return Device paths of all the children that support GraphicsOutput protocol.
685 EFI_DEVICE_PATH_PROTOCOL
*
687 EfiBootManagerGetGopDevicePath (
688 IN EFI_HANDLE VideoController
692 Connect the platform active active video controller.
694 @param VideoController PCI handle of video controller.
696 @retval EFI_NOT_FOUND There is no active video controller.
697 @retval EFI_SUCCESS The video controller is connected.
701 EfiBootManagerConnectVideoController (
702 EFI_HANDLE VideoController OPTIONAL
706 // Boot Manager driver health library functions.
710 EFI_DRIVER_HEALTH_PROTOCOL
*DriverHealth
;
713 /// Driver relative handles
715 EFI_HANDLE DriverHealthHandle
;
716 EFI_HANDLE ControllerHandle
;
717 EFI_HANDLE ChildHandle
;
720 /// Driver health messages of the specify Driver
722 EFI_DRIVER_HEALTH_HII_MESSAGE
*MessageList
;
725 /// HII relative handles
727 EFI_HII_HANDLE HiiHandle
;
730 /// Driver Health status
732 EFI_DRIVER_HEALTH_STATUS HealthStatus
;
733 } EFI_BOOT_MANAGER_DRIVER_HEALTH_INFO
;
736 Return all the Driver Health information.
738 When the cumulative health status of all the controllers managed by the
739 driver who produces the EFI_DRIVER_HEALTH_PROTOCOL is healthy, only one
740 EFI_BOOT_MANAGER_DRIVER_HEALTH_INFO entry is created for such
741 EFI_DRIVER_HEALTH_PROTOCOL instance.
742 Otherwise, every controller creates one EFI_BOOT_MANAGER_DRIVER_HEALTH_INFO
743 entry. Additionally every child controller creates one
744 EFI_BOOT_MANAGER_DRIVER_HEALTH_INFO entry if the driver is a bus driver.
746 @param Count Return the count of the Driver Health information.
748 @retval NULL No Driver Health information is returned.
749 @retval !NULL Pointer to the Driver Health information array.
751 EFI_BOOT_MANAGER_DRIVER_HEALTH_INFO
*
753 EfiBootManagerGetDriverHealthInfo (
758 Free the Driver Health information array.
760 @param DriverHealthInfo Pointer to array of the Driver Health information.
761 @param Count Count of the array.
763 @retval EFI_SUCCESS The array is freed.
764 @retval EFI_INVALID_PARAMETER The array is NULL.
768 EfiBootManagerFreeDriverHealthInfo (
769 EFI_BOOT_MANAGER_DRIVER_HEALTH_INFO
*DriverHealthInfo
,
774 Process (load and execute) the load option.
776 @param LoadOption Pointer to the load option.
778 @retval EFI_INVALID_PARAMETER The load option type is invalid,
779 or the load option file path doesn't point to a valid file.
780 @retval EFI_UNSUPPORTED The load option type is of LoadOptionTypeBoot.
781 @retval EFI_SUCCESS The load option is inactive, or successfully loaded and executed.
785 EfiBootManagerProcessLoadOption (
786 EFI_BOOT_MANAGER_LOAD_OPTION
*LoadOption
790 Check whether the VariableName is a valid load option variable name
791 and return the load option type and option number.
793 @param VariableName The name of the load option variable.
794 @param OptionType Return the load option type.
795 @param OptionNumber Return the load option number.
797 @retval TRUE The variable name is valid; The load option type and
798 load option number are returned.
799 @retval FALSE The variable name is NOT valid.
803 EfiBootManagerIsValidLoadOptionVariableName (
804 IN CHAR16
*VariableName
,
805 OUT EFI_BOOT_MANAGER_LOAD_OPTION_TYPE
*OptionType OPTIONAL
,
806 OUT UINT16
*OptionNumber OPTIONAL
811 Dispatch the deferred images that are returned from all DeferredImageLoad instances.
813 @retval EFI_SUCCESS At least one deferred image is loaded successfully and started.
814 @retval EFI_NOT_FOUND There is no deferred image.
815 @retval EFI_ACCESS_DENIED There are deferred images but all of them are failed to load.
819 EfiBootManagerDispatchDeferredImages (