[mirror_edk2.git] / MdePkg / Include / Uefi / UefiSpec.h

/** @file\r
  Include file that supports UEFI.\r
\r
  This include file must only contain things defined in the UEFI 2.1 specification.\r
  If a code construct is defined in the UEFI 2.1 specification it must be included\r
  by this include file.\r
\r
  Copyright (c) 2006 - 2008, Intel Corporation\r
  All rights reserved. This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#ifndef __UEFI_SPEC_H__\r
#define __UEFI_SPEC_H__\r
\r
#include <Uefi/UefiMultiPhase.h>\r
\r
#include <Protocol/DevicePath.h>\r
#include <Protocol/SimpleTextIn.h>\r
#include <Protocol/SimpleTextOut.h>\r
\r
///\r
/// Enumeration of EFI memory allocation types.\r
///\r
typedef enum {\r
  ///\r
  /// Allocate any available range of pages that satisfies the request\r
  ///\r
  AllocateAnyPages,\r
  ///\r
  /// Allocate any available range of pages whose uppermost address is less than \r
  /// or equal to a specified maximum address\r
  ///\r
  AllocateMaxAddress,\r
  ///\r
  /// Allocate pages at a specified address\r
  ///\r
  AllocateAddress,\r
  ///\r
  /// Maximum enumeration value that may be used for bounds checking\r
  ///\r
  MaxAllocateType\r
} EFI_ALLOCATE_TYPE;\r
\r
//\r
// Bit definitions for EFI_TIME.Daylight\r
//\r
#define EFI_TIME_ADJUST_DAYLIGHT  0x01\r
#define EFI_TIME_IN_DAYLIGHT      0x02\r
\r
///\r
/// Value definition for EFI_TIME.TimeZone\r
///\r
#define EFI_UNSPECIFIED_TIMEZONE  0x07FF\r
\r
//\r
// Memory cacheability attributes\r
//\r
#define EFI_MEMORY_UC   0x0000000000000001ULL\r
#define EFI_MEMORY_WC   0x0000000000000002ULL\r
#define EFI_MEMORY_WT   0x0000000000000004ULL\r
#define EFI_MEMORY_WB   0x0000000000000008ULL\r
#define EFI_MEMORY_UCE  0x0000000000000010ULL\r
//\r
// Physical memory protection attributes\r
//\r
#define EFI_MEMORY_WP   0x0000000000001000ULL\r
#define EFI_MEMORY_RP   0x0000000000002000ULL\r
#define EFI_MEMORY_XP   0x0000000000004000ULL\r
//\r
// Runtime memory attribute\r
//\r
#define EFI_MEMORY_RUNTIME  0x8000000000000000ULL\r
\r
///\r
/// Memory descriptor version number\r
///\r
#define EFI_MEMORY_DESCRIPTOR_VERSION 1\r
\r
///\r
/// Definition of an EFI memory descriptor\r
///\r
typedef struct {\r
  ///\r
  /// Type of the memory region.  See EFI_MEMORY_TYPE\r
  ///\r
  UINT32                Type;\r
  ///\r
  /// Physical address of the first byte of the memory region.  Must aligned \r
  /// on a 4 KB boundary.\r
  ///\r
  EFI_PHYSICAL_ADDRESS  PhysicalStart;\r
  ///\r
  /// Virtual address of the first byte of the memory region.  Must aligned \r
  /// on a 4 KB boundary.\r
  ///\r
  EFI_VIRTUAL_ADDRESS   VirtualStart;\r
  ///\r
  /// Number of 4KB pages in the memory region.\r
  ///\r
  UINT64                NumberOfPages;\r
  ///\r
  /// Attributes of the memory region that describe the bit mask of capabilities\r
  /// for that memory region, and not necessarily the current settings for that \r
  /// memory region.\r
  ///\r
  UINT64                Attribute;\r
} EFI_MEMORY_DESCRIPTOR;\r
\r
/**\r
  Allocates memory pages from the system.\r
\r
  @param  Type        The type of allocation to perform.\r
  @param  MemoryType  The type of memory to allocate.\r
  @param  Pages       The number of contiguous 4 KB pages to allocate.\r
  @param  Memory      Pointer to a physical address. On input, the way in which the address is\r
                      used depends on the value of Type.\r
\r
  @retval EFI_SUCCESS           The requested pages were allocated.\r
  @retval EFI_INVALID_PARAMETER 1) Type is not AllocateAnyPages or\r
                                AllocateMaxAddress or AllocateAddress.\r
                                2) MemoryType is in the range\r
                                EfiMaxMemoryType..0x7FFFFFFF.\r
  @retval EFI_OUT_OF_RESOURCES  The pages could not be allocated.\r
  @retval EFI_NOT_FOUND         The requested pages could not be found.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_ALLOCATE_PAGES)(\r
  IN     EFI_ALLOCATE_TYPE            Type,\r
  IN     EFI_MEMORY_TYPE              MemoryType,\r
  IN     UINTN                        Pages,\r
  IN OUT EFI_PHYSICAL_ADDRESS         *Memory\r
  );\r
\r
/**\r
  Frees memory pages.\r
\r
  @param  Memory      The base physical address of the pages to be freed.\r
  @param  Pages       The number of contiguous 4 KB pages to free.\r
\r
  @retval EFI_SUCCESS           The requested pages were freed.\r
  @retval EFI_INVALID_PARAMETER Memory is not a page-aligned address or Pages is invalid.\r
  @retval EFI_NOT_FOUND         The requested memory pages were not allocated with\r
                                AllocatePages().\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_FREE_PAGES)(\r
  IN  EFI_PHYSICAL_ADDRESS         Memory,\r
  IN  UINTN                        Pages\r
  );\r
\r
/**\r
  Returns the current memory map.\r
\r
  @param  MemoryMapSize         A pointer to the size, in bytes, of the MemoryMap buffer.\r
                                On input, this is the size of the buffer allocated by the caller.\r
                                On output, it is the size of the buffer returned by the firmware if\r
                                the buffer was large enough, or the size of the buffer needed to contain\r
                                the map if the buffer was too small.\r
  @param  MemoryMap             A pointer to the buffer in which firmware places the current memory\r
                                map.\r
  @param  MapKey                A pointer to the location in which firmware returns the key for the\r
                                current memory map.\r
  @param  DescriptorSize        A pointer to the location in which firmware returns the size, in bytes, of\r
                                an individual EFI_MEMORY_DESCRIPTOR.\r
  @param  DescriptorVersion     A pointer to the location in which firmware returns the version number\r
                                associated with the EFI_MEMORY_DESCRIPTOR.\r
\r
  @retval EFI_SUCCESS           The memory map was returned in the MemoryMap buffer.\r
  @retval EFI_BUFFER_TOO_SMALL  The MemoryMap buffer was too small. The current buffer size\r
                                needed to hold the memory map is returned in MemoryMapSize.\r
  @retval EFI_INVALID_PARAMETER 1) MemoryMapSize is NULL.\r
                                2) The MemoryMap buffer is not too small and MemoryMap is\r
                                   NULL.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_GET_MEMORY_MAP)(\r
  IN OUT UINTN                       *MemoryMapSize,\r
  IN OUT EFI_MEMORY_DESCRIPTOR       *MemoryMap,\r
  OUT    UINTN                       *MapKey,\r
  OUT    UINTN                       *DescriptorSize,\r
  OUT    UINT32                      *DescriptorVersion\r
  );\r
\r
/**\r
  Allocates pool memory.\r
\r
  @param  PoolType              The type of pool to allocate.\r
  @param  Size                  The number of bytes to allocate from the pool.\r
  @param  Buffer                A pointer to a pointer to the allocated buffer if the call succeeds;\r
                                undefined otherwise.\r
\r
  @retval EFI_SUCCESS           The requested number of bytes was allocated.\r
  @retval EFI_OUT_OF_RESOURCES  The pool requested could not be allocated.\r
  @retval EFI_INVALID_PARAMETER PoolType was invalid.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_ALLOCATE_POOL)(\r
  IN  EFI_MEMORY_TYPE              PoolType,\r
  IN  UINTN                        Size,\r
  OUT VOID                         **Buffer\r
  );\r
\r
/**\r
  Returns pool memory to the system.\r
\r
  @param  Buffer                Pointer to the buffer to free.\r
\r
  @retval EFI_SUCCESS           The memory was returned to the system.\r
  @retval EFI_INVALID_PARAMETER Buffer was invalid.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_FREE_POOL)(\r
  IN  VOID                         *Buffer\r
  );\r
\r
/**\r
  Changes the runtime addressing mode of EFI firmware from physical to virtual.\r
\r
  @param  MemoryMapSize         The size in bytes of VirtualMap.\r
  @param  DescriptorSize        The size in bytes of an entry in the VirtualMap.\r
  @param  DescriptorVersion     The version of the structure entries in VirtualMap.\r
  @param  VirtualMap            An array of memory descriptors which contain new virtual\r
                                address mapping information for all runtime ranges.\r
\r
  @retval EFI_SUCCESS           The virtual address map has been applied.\r
  @retval EFI_UNSUPPORTED       EFI firmware is not at runtime, or the EFI firmware is already in\r
                                virtual address mapped mode.\r
  @retval EFI_INVALID_PARAMETER DescriptorSize or DescriptorVersion is invalid.\r
  @retval EFI_NO_MAPPING        A virtual address was not supplied for a range in the memory\r
                                map that requires a mapping.\r
  @retval EFI_NOT_FOUND         A virtual address was supplied for an address that is not found\r
                                in the memory map.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_SET_VIRTUAL_ADDRESS_MAP)(\r
  IN  UINTN                        MemoryMapSize,\r
  IN  UINTN                        DescriptorSize,\r
  IN  UINT32                       DescriptorVersion,\r
  IN  EFI_MEMORY_DESCRIPTOR        *VirtualMap\r
  );\r
\r
/**\r
  Connects one or more drivers to a controller.\r
\r
  @param  ControllerHandle      The handle of the controller to which driver(s) are to be connected.\r
  @param  DriverImageHandle     A pointer to an ordered list handles that support the\r
                                EFI_DRIVER_BINDING_PROTOCOL.\r
  @param  RemainingDevicePath   A pointer to the device path that specifies a child of the\r
                                controller specified by ControllerHandle.\r
  @param  Recursive             If TRUE, then ConnectController() is called recursively\r
                                until the entire tree of controllers below the controller specified\r
                                by ControllerHandle have been created. If FALSE, then\r
                                the tree of controllers is only expanded one level.\r
\r
  @retval EFI_SUCCESS           1) One or more drivers were connected to ControllerHandle.\r
                                2) No drivers were connected to ControllerHandle, but\r
                                RemainingDevicePath is not NULL, and it is an End Device\r
                                Path Node.\r
  @retval EFI_INVALID_PARAMETER ControllerHandle is not a valid EFI_HANDLE.\r
  @retval EFI_NOT_FOUND         1) There are no EFI_DRIVER_BINDING_PROTOCOL instances\r
                                present in the system.\r
                                2) No drivers were connected to ControllerHandle.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_CONNECT_CONTROLLER)(\r
  IN  EFI_HANDLE                    ControllerHandle,\r
  IN  EFI_HANDLE                    *DriverImageHandle,   OPTIONAL\r
  IN  EFI_DEVICE_PATH_PROTOCOL      *RemainingDevicePath, OPTIONAL\r
  IN  BOOLEAN                       Recursive\r
  );\r
\r
/**\r
  Disconnects one or more drivers from a controller.\r
\r
  @param  ControllerHandle      The handle of the controller from which driver(s) are to be disconnected.\r
  @param  DriverImageHandle     The driver to disconnect from ControllerHandle.\r
                                If DriverImageHandle is NULL, then all the drivers currently managing\r
                                ControllerHandle are disconnected from ControllerHandle.\r
  @param  ChildHandle           The handle of the child to destroy.\r
                                If ChildHandle is NULL, then all the children of ControllerHandle are\r
                                destroyed before the drivers are disconnected from ControllerHandle.\r
\r
  @retval EFI_SUCCESS           1) One or more drivers were disconnected from the controller.\r
                                2) On entry, no drivers are managing ControllerHandle.\r
                                3) DriverImageHandle is not NULL, and on entry\r
                                   DriverImageHandle is not managing ControllerHandle.\r
  @retval EFI_INVALID_PARAMETER 1) ControllerHandle is not a valid EFI_HANDLE.\r
                                2) DriverImageHandle is not NULL, and it is not a valid EFI_HANDLE.\r
                                3) ChildHandle is not NULL, and it is not a valid EFI_HANDLE.\r
                                4) DriverImageHandle does not support the EFI_DRIVER_BINDING_PROTOCOL.\r
  @retval EFI_OUT_OF_RESOURCES  There are not enough resources available to disconnect any drivers from\r
                                ControllerHandle.\r
  @retval EFI_DEVICE_ERROR      The controller could not be disconnected because of a device error.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_DISCONNECT_CONTROLLER)(\r
  IN  EFI_HANDLE                     ControllerHandle,\r
  IN  EFI_HANDLE                     DriverImageHandle, OPTIONAL\r
  IN  EFI_HANDLE                     ChildHandle        OPTIONAL\r
  );\r
\r
\r
\r
//\r
// ConvertPointer DebugDisposition type.\r
//\r
#define EFI_OPTIONAL_PTR     0x00000001\r
#define EFI_OPTIONAL_POINTER EFI_OPTIONAL_PTR\r
\r
/**\r
  Determines the new virtual address that is to be used on subsequent memory accesses.\r
\r
  @param  DebugDisposition      Supplies type information for the pointer being converted.\r
  @param  Address               A pointer to a pointer that is to be fixed to be the value needed\r
                                for the new virtual address mappings being applied.\r
\r
  @retval EFI_SUCCESS           The pointer pointed to by Address was modified.\r
  @retval EFI_INVALID_PARAMETER 1) Address is NULL.\r
                                2) *Address is NULL and DebugDisposition does\r
                                not have the EFI_OPTIONAL_PTR bit set.\r
  @retval EFI_NOT_FOUND         The pointer pointed to by Address was not found to be part\r
                                of the current memory map. This is normally fatal.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_CONVERT_POINTER)(\r
  IN     UINTN                      DebugDisposition,\r
  IN OUT VOID                       **Address\r
  );\r
\r
\r
//\r
// These types can be ORed together as needed - for example,\r
// EVT_TIMER might be Ored with EVT_NOTIFY_WAIT or\r
// EVT_NOTIFY_SIGNAL.\r
//\r
#define EVT_TIMER                         0x80000000\r
#define EVT_RUNTIME                       0x40000000\r
#define EVT_NOTIFY_WAIT                   0x00000100\r
#define EVT_NOTIFY_SIGNAL                 0x00000200\r
\r
#define EVT_SIGNAL_EXIT_BOOT_SERVICES     0x00000201\r
#define EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE 0x60000202\r
\r
//\r
// The event's NotifyContext pointer points to a runtime memory\r
// address.\r
// The event is deprecated in UEFI2.0 and later specifications.\r
//\r
#define EVT_RUNTIME_CONTEXT               0x20000000\r
\r
\r
/**\r
  Invoke a notification event\r
\r
  @param  Event                 Event whose notification function is being invoked.\r
  @param  Context               Pointer to the notification function's context,\r
                                which is implementation-dependent.\r
\r
**/\r
typedef\r
VOID\r
(EFIAPI *EFI_EVENT_NOTIFY)(\r
  IN  EFI_EVENT                Event,\r
  IN  VOID                     *Context\r
  );\r
\r
/**\r
  Creates an event.\r
\r
  @param  Type                  The type of event to create and its mode and attributes.\r
  @param  NotifyTpl             The task priority level of event notifications, if needed.\r
  @param  NotifyFunction        Pointer to the event's notification function, if any.\r
  @param  NotifyContext         Pointer to the notification function's context; corresponds to parameter\r
                                Context in the notification function.\r
  @param  Event                 Pointer to the newly created event if the call succeeds; undefined\r
                                otherwise.\r
\r
  @retval EFI_SUCCESS           The event structure was created.\r
  @retval EFI_INVALID_PARAMETER One or more parameters are invalid.\r
  @retval EFI_OUT_OF_RESOURCES  The event could not be allocated.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_CREATE_EVENT)(\r
  IN  UINT32                       Type,\r
  IN  EFI_TPL                      NotifyTpl,\r
  IN  EFI_EVENT_NOTIFY             NotifyFunction,\r
  IN  VOID                         *NotifyContext,\r
  OUT EFI_EVENT                    *Event\r
  );\r
\r
/**\r
  Creates an event in a group.\r
\r
  @param  Type                  The type of event to create and its mode and attributes.\r
  @param  NotifyTpl             The task priority level of event notifications,if needed.\r
  @param  NotifyFunction        Pointer to the event's notification function, if any.\r
  @param  NotifyContext         Pointer to the notification function's context; corresponds to parameter\r
                                Context in the notification function.\r
  @param  EventGroup            Pointer to the unique identifier of the group to which this event belongs.\r
                                If this is NULL, then the function behaves as if the parameters were passed\r
                                to CreateEvent.\r
  @param  Event                 Pointer to the newly created event if the call succeeds; undefined\r
                                otherwise.\r
\r
  @retval EFI_SUCCESS           The event structure was created.\r
  @retval EFI_INVALID_PARAMETER One or more parameters are invalid.\r
  @retval EFI_OUT_OF_RESOURCES  The event could not be allocated.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_CREATE_EVENT_EX)(\r
  IN       UINT32                 Type,\r
  IN       EFI_TPL                NotifyTpl,\r
  IN       EFI_EVENT_NOTIFY       NotifyFunction OPTIONAL,\r
  IN CONST VOID                   *NotifyContext OPTIONAL,\r
  IN CONST EFI_GUID               *EventGroup    OPTIONAL,\r
  OUT      EFI_EVENT              *Event\r
  );\r
\r
///\r
/// Timer delay types\r
///\r
typedef enum {\r
  ///\r
  /// An event's timer settings is to be cancelled and not trigger time is to be set\r
  ///\r
  TimerCancel,\r
  ///\r
  /// An event is to be signalled periodically at a specified interval from the current time.\r
  ///\r
  TimerPeriodic,\r
  ///\r
  /// An event is to be signalled once at a specified interval from the current time.\r
  ///\r
  TimerRelative\r
} EFI_TIMER_DELAY;\r
\r
/**\r
  Sets the type of timer and the trigger time for a timer event.\r
\r
  @param  Event                 The timer event that is to be signaled at the specified time.\r
  @param  Type                  The type of time that is specified in TriggerTime.\r
  @param  TriggerTime           The number of 100ns units until the timer expires.\r
                                A TriggerTime of 0 is legal.\r
                                If Type is TimerRelative and TriggerTime is 0, then the timer\r
                                event will be signaled on the next timer tick.\r
                                If Type is TimerPeriodic and TriggerTime is 0, then the timer\r
                                event will be signaled on every timer tick.\r
\r
  @retval EFI_SUCCESS           The event has been set to be signaled at the requested time.\r
  @retval EFI_INVALID_PARAMETER Event or Type is not valid.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_SET_TIMER)(\r
  IN  EFI_EVENT                Event,\r
  IN  EFI_TIMER_DELAY          Type,\r
  IN  UINT64                   TriggerTime\r
  );\r
\r
/**\r
  Signals an event.\r
\r
  @param  Event                 The event to signal.\r
\r
  @retval EFI_SUCCESS           The event has been signaled.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_SIGNAL_EVENT)(\r
  IN  EFI_EVENT                Event\r
  );\r
\r
/**\r
  Stops execution until an event is signaled.\r
\r
  @param  NumberOfEvents        The number of events in the Event array.\r
  @param  Event                 An array of EFI_EVENT.\r
  @param  Index                 Pointer to the index of the event which satisfied the wait condition.\r
\r
  @retval EFI_SUCCESS           The event indicated by Index was signaled.\r
  @retval EFI_INVALID_PARAMETER 1) NumberOfEvents is 0.\r
                                2) The event indicated by Index is of type\r
                                   EVT_NOTIFY_SIGNAL.\r
  @retval EFI_UNSUPPORTED       The current TPL is not TPL_APPLICATION.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_WAIT_FOR_EVENT)(\r
  IN  UINTN                    NumberOfEvents,\r
  IN  EFI_EVENT                *Event,\r
  OUT UINTN                    *Index\r
  );\r
\r
/**\r
  Closes an event.\r
\r
  @param  Event                 The event to close.\r
\r
  @retval EFI_SUCCESS           The event has been closed.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_CLOSE_EVENT)(\r
  IN EFI_EVENT                Event\r
  );\r
\r
/**\r
  Checks whether an event is in the signaled state.\r
\r
  @param  Event                 The event to check.\r
\r
  @retval EFI_SUCCESS           The event is in the signaled state.\r
  @retval EFI_NOT_READY         The event is not in the signaled state.\r
  @retval EFI_INVALID_PARAMETER Event is of type EVT_NOTIFY_SIGNAL.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_CHECK_EVENT)(\r
  IN EFI_EVENT                Event\r
  );\r
\r
\r
//\r
// Task priority level\r
//\r
#define TPL_APPLICATION       4\r
#define TPL_CALLBACK          8\r
#define TPL_NOTIFY            16\r
#define TPL_HIGH_LEVEL        31\r
\r
\r
/**\r
  Raises a task's priority level and returns its previous level.\r
\r
  @param  NewTpl                The new task priority level.\r
\r
  @return Previous task priority level\r
\r
**/\r
typedef\r
EFI_TPL\r
(EFIAPI *EFI_RAISE_TPL)(\r
  IN EFI_TPL      NewTpl\r
  );\r
\r
/**\r
  Restores a task's priority level to its previous value.\r
\r
  @param  OldTpl                The previous task priority level to restore.\r
\r
**/\r
typedef\r
VOID\r
(EFIAPI *EFI_RESTORE_TPL)(\r
  IN EFI_TPL      OldTpl\r
  );\r
\r
/**\r
  Returns the value of a variable.\r
\r
  @param  VariableName          A Null-terminated Unicode string that is the name of the\r
                                vendor's variable.\r
  @param  VendorGuid            A unique identifier for the vendor.\r
  @param  Attributes            If not NULL, a pointer to the memory location to return the\r
                                attributes bitmask for the variable.\r
  @param  DataSize              On input, the size in bytes of the return Data buffer.\r
                                On output the size of data returned in Data.\r
  @param  Data                  The buffer to return the contents of the variable.\r
\r
  @retval EFI_SUCCESS            The function completed successfully.\r
  @retval EFI_NOT_FOUND          The variable was not found.\r
  @retval EFI_BUFFER_TOO_SMALL   The DataSize is too small for the result.\r
  @retval EFI_INVALID_PARAMETER  VariableName is NULL.\r
  @retval EFI_INVALID_PARAMETER  VendorGuid is NULL.\r
  @retval EFI_INVALID_PARAMETER  DataSize is NULL.\r
  @retval EFI_INVALID_PARAMETER  The DataSize is not too small and Data is NULL.\r
  @retval EFI_DEVICE_ERROR       The variable could not be retrieved due to a hardware error.\r
  @retval EFI_SECURITY_VIOLATION The variable could not be retrieved due to an authentication failure.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_GET_VARIABLE)(\r
  IN     CHAR16                      *VariableName,\r
  IN     EFI_GUID                    *VendorGuid,\r
  OUT    UINT32                      *Attributes,    OPTIONAL\r
  IN OUT UINTN                       *DataSize,\r
  OUT    VOID                        *Data\r
  );\r
\r
/**\r
  Enumerates the current variable names.\r
\r
  @param  VariableNameSize      The size of the VariableName buffer.\r
  @param  VariableName          On input, supplies the last VariableName that was returned\r
                                by GetNextVariableName(). On output, returns the Nullterminated\r
                                Unicode string of the current variable.\r
  @param  VendorGuid            On input, supplies the last VendorGuid that was returned by\r
                                GetNextVariableName(). On output, returns the\r
                                VendorGuid of the current variable.\r
\r
  @retval EFI_SUCCESS           The function completed successfully.\r
  @retval EFI_NOT_FOUND         The next variable was not found.\r
  @retval EFI_BUFFER_TOO_SMALL  The VariableNameSize is too small for the result.\r
  @retval EFI_INVALID_PARAMETER VariableNameSize is NULL.\r
  @retval EFI_INVALID_PARAMETER VariableName is NULL.\r
  @retval EFI_INVALID_PARAMETER VendorGuid is NULL.\r
  @retval EFI_DEVICE_ERROR      The variable could not be retrieved due to a hardware error.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_GET_NEXT_VARIABLE_NAME)(\r
  IN OUT UINTN                    *VariableNameSize,\r
  IN OUT CHAR16                   *VariableName,\r
  IN OUT EFI_GUID                 *VendorGuid\r
  );\r
\r
/**\r
  Sets the value of a variable.\r
\r
  @param  VariableName          A Null-terminated Unicode string that is the name of the\r
                                vendor's variable.\r
  @param  VendorGuid            A unique identifier for the vendor.\r
  @param  Attributes            Attributes bitmask to set for the variable.\r
  @param  DataSize              The size in bytes of the Data buffer.\r
  @param  Data                  The contents for the variable.\r
\r
  @retval EFI_SUCCESS            The firmware has successfully stored the variable and its data as\r
                                 defined by the Attributes.\r
  @retval EFI_INVALID_PARAMETER  An invalid combination of attribute bits was supplied, or the\r
                                 DataSize exceeds the maximum allowed.\r
  @retval EFI_INVALID_PARAMETER  VariableName is an empty Unicode string.\r
  @retval EFI_OUT_OF_RESOURCES   Not enough storage is available to hold the variable and its data.\r
  @retval EFI_DEVICE_ERROR       The variable could not be retrieved due to a hardware error.\r
  @retval EFI_WRITE_PROTECTED    The variable in question is read-only.\r
  @retval EFI_WRITE_PROTECTED    The variable in question cannot be deleted.\r
  @retval EFI_SECURITY_VIOLATION The variable could not be retrieved due to an authentication failure.\r
  @retval EFI_NOT_FOUND          The variable trying to be updated or deleted was not found.\r
\r
**/\r
typedef\r
EFI_STATUS\r
(EFIAPI *EFI_SET_VARIABLE)(\r
  IN  CHAR16                       *VariableName,\r
  IN  EFI_GUID                     *VendorGuid,\r
  IN  UINT32                       Attributes,\r
  IN  UINTN                        DataSize,\r
  IN  VOID                         *Data\r
  );\r
\r
\r
///\r
/// This provides the capabilities of the\r
/// real time clock device as exposed through the EFI interfaces.\r
///\r
typedef struct {\r
  ///\r
  /// Provides the reporting resolution of the real-time clock device in\r
  /// counts per second. For a normal PC-AT CMOS RTC device, this\r
  /// value would be 1 Hz, or 1, to indicate that the device only reports\r
  /// the time to the resolution of 1 second.\r
  ///\r
  UINT32    Resolution;\r
  ///\r
  /// Provides the timekeeping accuracy of the real-time clock in an\r
  /// error rate of 1E-6 parts per million. For a clock with an accuracy\r
  /// of 50 parts per million, the value in this field would be\r
  /// 50,000,000.\r
  ///\r
  UINT32    Accuracy;\r
  ///\r