MdePkg/Library/UefiLib/UefiLib.c - SHIFTPHONES/android_bootable_bootloader_edk2 - Gitiles

 /** @file
   Mde UEFI library functions.

   Copyright (c) 2006, Intel Corporation<BR>
   All rights reserved. This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
   http://opensource.org/licenses/bsd-license.php

   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

   Module Name:  UefiLib.c

 **/

 /**
   Compare whether two names of languages are identical.

   @param  Language1 Name of language 1.
   @param  Language2 Name of language 2.

   @retval TRUE      Language 1 and language 2 are the same.
   @retval FALSE     Language 1 and language 2 are not the same.

 **/
 BOOLEAN
 CompareIso639LanguageCode (
   IN CONST CHAR8  *Language1,
   IN CONST CHAR8  *Language2
   )
 {
   return (BOOLEAN) (ReadUnaligned24 ((CONST UINT32 *) Language1) == ReadUnaligned24 ((CONST UINT32 *) Language2));
 }

 /**
   This function searches the list of configuration tables stored in the EFI System
   Table for a table with a GUID that matches TableGuid.  If a match is found,
   then a pointer to the configuration table is returned in Table, and EFI_SUCCESS
   is returned.  If a matching GUID is not found, then EFI_NOT_FOUND is returned.

   @param  TableGuid       Pointer to table's GUID type..
   @param  Table           Pointer to the table associated with TableGuid in the EFI System Table.

   @retval EFI_SUCCESS     A configuration table matching TableGuid was found.
   @retval EFI_NOT_FOUND   A configuration table matching TableGuid could not be found.

 **/
 EFI_STATUS
 EFIAPI
 EfiGetSystemConfigurationTable (
   IN  EFI_GUID  *TableGuid,
   OUT VOID      **Table
   )
 {
   EFI_SYSTEM_TABLE  *SystemTable;
   UINTN             Index;

   ASSERT (TableGuid != NULL);
   ASSERT (Table != NULL);

   SystemTable = gST;
   *Table = NULL;
   for (Index = 0; Index < SystemTable->NumberOfTableEntries; Index++) {
     if (CompareGuid (TableGuid, &(SystemTable->ConfigurationTable[Index].VendorGuid))) {
       *Table = SystemTable->ConfigurationTable[Index].VendorTable;
       return EFI_SUCCESS;
     }
   }

   return EFI_NOT_FOUND;
 }

 /**
   This function causes the notification function to be executed for every protocol
   of type ProtocolGuid instance that exists in the system when this function is
   invoked.  In addition, every time a protocol of type ProtocolGuid instance is
   installed or reinstalled, the notification function is also executed.

   @param  ProtocolGuid    Supplies GUID of the protocol upon whose installation the event is fired.
   @param  NotifyTpl       Supplies the task priority level of the event notifications.
   @param  NotifyFunction  Supplies the function to notify when the event is signaled.
   @param  NotifyContext   The context parameter to pass to NotifyFunction.
   @param  Registration    A pointer to a memory location to receive the registration value.

   @return The notification event that was created.

 **/
 EFI_EVENT
 EFIAPI
 EfiCreateProtocolNotifyEvent(
   IN  EFI_GUID          *ProtocolGuid,
   IN  EFI_TPL           NotifyTpl,
   IN  EFI_EVENT_NOTIFY  NotifyFunction,
   IN  VOID              *NotifyContext,  OPTIONAL
   OUT VOID              *Registration
   )
 {
   EFI_STATUS  Status;
   EFI_EVENT   Event;

   //
   // Create the event
   //

   Status = gBS->CreateEvent (
                   EFI_EVENT_NOTIFY_SIGNAL,
                   NotifyTpl,
                   NotifyFunction,
                   NotifyContext,
                   &Event
                   );
   ASSERT_EFI_ERROR (Status);

   //
   // Register for protocol notifactions on this event
   //

   Status = gBS->RegisterProtocolNotify (
                   ProtocolGuid,
                   Event,
                   Registration
                   );

   ASSERT_EFI_ERROR (Status);

   //
   // Kick the event so we will perform an initial pass of
   // current installed drivers
   //

   gBS->SignalEvent (Event);
   return Event;
 }

 /**
   This function creates an event using NotifyTpl, NoifyFunction, and NotifyContext.
   This event is signaled with EfiNamedEventSignal().  This provide the ability for
   one or more listeners on the same event named by the GUID specified by Name.

   @param  Name                  Supplies GUID name of the event.
   @param  NotifyTpl             Supplies the task priority level of the event notifications.
   @param  NotifyFunction        Supplies the function to notify when the event is signaled.
   @param  NotifyContext         The context parameter to pass to NotifyFunction.
   @param  Registration          A pointer to a memory location to receive the registration value.

   @retval EFI_SUCCESS           A named event was created.
   @retval EFI_OUT_OF_RESOURCES  There are not enough resource to create the named event.

 **/
 EFI_STATUS
 EFIAPI
 EfiNamedEventListen (
   IN CONST EFI_GUID    *Name,
   IN EFI_TPL           NotifyTpl,
   IN EFI_EVENT_NOTIFY  NotifyFunction,
   IN CONST VOID        *NotifyContext,  OPTIONAL
   OUT VOID             *Registration    OPTIONAL
   )
 {
   EFI_STATUS  Status;
   EFI_EVENT   Event;
   VOID        *RegistrationLocal;

   //
   // Create event
   //
   Status = gBS->CreateEvent (
                   EFI_EVENT_NOTIFY_SIGNAL,
                   NotifyTpl,
                   NotifyFunction,
                   (VOID *) NotifyContext,
                   &Event
                   );
   ASSERT_EFI_ERROR (Status);

   //
   // The Registration is not optional to RegisterProtocolNotify().
   // To make it optional to EfiNamedEventListen(), may need to substitute with a local.
   //
   if (Registration != NULL) {
     RegistrationLocal = Registration;
   } else {
     RegistrationLocal = &RegistrationLocal;
   }

   //
   // Register for an installation of protocol interface
   //

   Status = gBS->RegisterProtocolNotify (
                   (EFI_GUID *) Name,
                   Event,
                   RegistrationLocal
                   );
   ASSERT_EFI_ERROR (Status);

   return EFI_SUCCESS;
 }

 /**
   This function signals the named event specified by Name.  The named event must
   have been created with EfiNamedEventListen().

   @param  Name                  Supplies GUID name of the event.

   @retval EFI_SUCCESS           A named event was signaled.
   @retval EFI_OUT_OF_RESOURCES  There are not enough resource to signal the named event.

 **/
 EFI_STATUS
 EFIAPI
 EfiNamedEventSignal (
   IN CONST EFI_GUID  *Name
   )
 {
   EFI_STATUS  Status;
   EFI_HANDLE  Handle;

   Handle = NULL;
   Status = gBS->InstallProtocolInterface (
                   &Handle,
                   (EFI_GUID *) Name,
                   EFI_NATIVE_INTERFACE,
                   NULL
                   );
   ASSERT_EFI_ERROR (Status);

   Status = gBS->UninstallProtocolInterface (
                   Handle,
                   (EFI_GUID *) Name,
                   NULL
                   );
   ASSERT_EFI_ERROR (Status);

   return EFI_SUCCESS;
 }


 /**
   This function initializes a basic mutual exclusion lock to the released state
   and returns the lock.  Each lock provides mutual exclusion access at its task
   priority level.  Since there is no preemption or multiprocessor support in EFI,
   acquiring the lock only consists of raising to the locks TPL.

   @param  Lock       A pointer to the lock data structure to initialize.
   @param  Priority   EFI TPL associated with the lock.

   @return The lock.

 **/
 EFI_LOCK *
 EFIAPI
 EfiInitializeLock (
   IN OUT EFI_LOCK  *Lock,
   IN EFI_TPL        Priority
   )
 {
   ASSERT (Lock != NULL);
   ASSERT (Priority <= EFI_TPL_HIGH_LEVEL);

   Lock->Tpl       = Priority;
   Lock->OwnerTpl  = EFI_TPL_APPLICATION;
   Lock->Lock      = EfiLockReleased ;
   return Lock;
 }

 /**
   This function raises the system¡¯s current task priority level to the task
   priority level of the mutual exclusion lock.  Then, it places the lock in the
   acquired state.

   @param  Priority  The task priority level of the lock.

 **/
 VOID
 EFIAPI
 EfiAcquireLock (
   IN EFI_LOCK  *Lock
   )
 {
   ASSERT (Lock != NULL);
   ASSERT (Lock->Lock == EfiLockReleased);

   Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);
   Lock->Lock     = EfiLockAcquired;
 }

 /**
   This function raises the system¡¯s current task priority level to the task
   priority level of the mutual exclusion lock.  Then, it attempts to place the
   lock in the acquired state.

   @param  Lock              A pointer to the lock to acquire.

   @retval EFI_SUCCESS       The lock was acquired.
   @retval EFI_ACCESS_DENIED The lock could not be acquired because it is already owned.

 **/
 EFI_STATUS
 EFIAPI
 EfiAcquireLockOrFail (
   IN EFI_LOCK  *Lock
   )
 {

   ASSERT (Lock != NULL);
   ASSERT (Lock->Lock != EfiLockUninitialized);

   if (Lock->Lock == EfiLockAcquired) {
     //
     // Lock is already owned, so bail out
     //
     return EFI_ACCESS_DENIED;
   }

   Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);

   Lock->Lock = EfiLockAcquired;

   return EFI_SUCCESS;
 }

 /**
   This function transitions a mutual exclusion lock from the acquired state to
   the released state, and restores the system¡¯s task priority level to its
   previous level.

   @param  Lock  A pointer to the lock to release.

 **/
 VOID
 EFIAPI
 EfiReleaseLock (
   IN EFI_LOCK  *Lock
   )
 {
   EFI_TPL Tpl;

   ASSERT (Lock != NULL);
   ASSERT (Lock->Lock == EfiLockAcquired);

   Tpl = Lock->OwnerTpl;

   Lock->Lock = EfiLockReleased;

   gBS->RestoreTPL (Tpl);
 }

 /**
   This function looks up a Unicode string in UnicodeStringTable.  If Language is
   a member of SupportedLanguages and a Unicode string is found in UnicodeStringTable
   that matches the language code specified by Language, then it is returned in
   UnicodeString.

   @param  Language                A pointer to the ISO 639-2 language code for the
                                   Unicode string to look up and return.
   @param  SupportedLanguages      A pointer to the set of ISO 639-2 language codes
                                   that the Unicode string table supports.  Language
                                   must be a member of this set.
   @param  UnicodeStringTable      A pointer to the table of Unicode strings.
   @param  UnicodeString           A pointer to the Unicode string from UnicodeStringTable
                                   that matches the language specified by Language.

   @retval  EFI_SUCCESS            The Unicode string that matches the language
                                   specified by Language was found
                                   in the table of Unicoide strings UnicodeStringTable,
                                   and it was returned in UnicodeString.
   @retval  EFI_INVALID_PARAMETER  Language is NULL.
   @retval  EFI_INVALID_PARAMETER  UnicodeString is NULL.
   @retval  EFI_UNSUPPORTED        SupportedLanguages is NULL.
   @retval  EFI_UNSUPPORTED        UnicodeStringTable is NULL.
   @retval  EFI_UNSUPPORTED        The language specified by Language is not a
                                   member of SupportedLanguages.
   @retval  EFI_UNSUPPORTED        The language specified by Language is not
                                   supported by UnicodeStringTable.

 **/
 EFI_STATUS
 EFIAPI
 LookupUnicodeString (
   IN CONST CHAR8                     *Language,
   IN CONST CHAR8                     *SupportedLanguages,
   IN CONST EFI_UNICODE_STRING_TABLE  *UnicodeStringTable,
   OUT CHAR16                         **UnicodeString
   )
 {
   //
   // Make sure the parameters are valid
   //
   if (Language == NULL || UnicodeString == NULL) {
     return EFI_INVALID_PARAMETER;
   }

   //
   // If there are no supported languages, or the Unicode String Table is empty, then the
   // Unicode String specified by Language is not supported by this Unicode String Table
   //
   if (SupportedLanguages == NULL || UnicodeStringTable == NULL) {
     return EFI_UNSUPPORTED;
   }

   //
   // Make sure Language is in the set of Supported Languages
   //
   while (*SupportedLanguages != 0) {
     if (CompareIso639LanguageCode (Language, SupportedLanguages)) {

       //
       // Search the Unicode String Table for the matching Language specifier
       //
       while (UnicodeStringTable->Language != NULL) {
         if (CompareIso639LanguageCode (Language, UnicodeStringTable->Language)) {

           //
           // A matching string was found, so return it
           //
           *UnicodeString = UnicodeStringTable->UnicodeString;
           return EFI_SUCCESS;
         }

         UnicodeStringTable++;
       }

       return EFI_UNSUPPORTED;
     }

     SupportedLanguages += 3;
   }

   return EFI_UNSUPPORTED;
 }

 /**
   This function adds a Unicode string to UnicodeStringTable.
   If Language is a member of SupportedLanguages then UnicodeString is added to
   UnicodeStringTable.  New buffers are allocated for both Language and
   UnicodeString.  The contents of Language and UnicodeString are copied into
   these new buffers.  These buffers are automatically freed when
   FreeUnicodeStringTable() is called.

   @param  Language                A pointer to the ISO 639-2 language code for the Unicode
                                   string to add.
   @param  SupportedLanguages      A pointer to the set of ISO 639-2 language codes
                                   that the Unicode string table supports.
                                   Language must be a member of this set.
   @param  UnicodeStringTable      A pointer to the table of Unicode strings.
   @param  UnicodeString           A pointer to the Unicode string to add.

   @retval EFI_SUCCESS             The Unicode string that matches the language
                                   specified by Language was found in the table of
                                   Unicode strings UnicodeStringTable, and it was
                                   returned in UnicodeString.
   @retval EFI_INVALID_PARAMETER   Language is NULL.
   @retval EFI_INVALID_PARAMETER   UnicodeString is NULL.
   @retval EFI_INVALID_PARAMETER   UnicodeString is an empty string.
   @retval EFI_UNSUPPORTED         SupportedLanguages is NULL.
   @retval EFI_ALREADY_STARTED     A Unicode string with language Language is
                                   already present in UnicodeStringTable.
   @retval EFI_OUT_OF_RESOURCES    There is not enough memory to add another
                                   Unicode string to UnicodeStringTable.
   @retval EFI_UNSUPPORTED         The language specified by Language is not a
                                   member of SupportedLanguages.

 **/
 EFI_STATUS
 EFIAPI
 AddUnicodeString (
   IN CONST CHAR8               *Language,
   IN CONST CHAR8               *SupportedLanguages,
   IN EFI_UNICODE_STRING_TABLE  **UnicodeStringTable,
   IN CONST CHAR16              *UnicodeString
   )
 {
   UINTN                     NumberOfEntries;
   EFI_UNICODE_STRING_TABLE  *OldUnicodeStringTable;
   EFI_UNICODE_STRING_TABLE  *NewUnicodeStringTable;
   UINTN                     UnicodeStringLength;

   //
   // Make sure the parameter are valid
   //
   if (Language == NULL || UnicodeString == NULL || UnicodeStringTable == NULL) {
     return EFI_INVALID_PARAMETER;
   }

   //
   // If there are no supported languages, then a Unicode String can not be added
   //
   if (SupportedLanguages == NULL) {
     return EFI_UNSUPPORTED;
   }

   //
   // If the Unicode String is empty, then a Unicode String can not be added
   //
   if (UnicodeString[0] == 0) {
     return EFI_INVALID_PARAMETER;
   }

   //
   // Make sure Language is a member of SupportedLanguages
   //
   while (*SupportedLanguages != 0) {
     if (CompareIso639LanguageCode (Language, SupportedLanguages)) {

       //
       // Determine the size of the Unicode String Table by looking for a NULL Language entry
       //
       NumberOfEntries = 0;
       if (*UnicodeStringTable != NULL) {
         OldUnicodeStringTable = *UnicodeStringTable;
         while (OldUnicodeStringTable->Language != NULL) {
           if (CompareIso639LanguageCode (Language, OldUnicodeStringTable->Language)) {
             return EFI_ALREADY_STARTED;
           }

           OldUnicodeStringTable++;
           NumberOfEntries++;
         }
       }

       //
       // Allocate space for a new Unicode String Table.  It must hold the current number of
       // entries, plus 1 entry for the new Unicode String, plus 1 entry for the end of table
       // marker
       //
       NewUnicodeStringTable = AllocatePool ((NumberOfEntries + 2) * sizeof (EFI_UNICODE_STRING_TABLE));
       if (NewUnicodeStringTable == NULL) {
         return EFI_OUT_OF_RESOURCES;
       }

       //
       // If the current Unicode String Table contains any entries, then copy them to the
       // newly allocated Unicode String Table.
       //
       if (*UnicodeStringTable != NULL) {
         CopyMem (
            NewUnicodeStringTable,
            *UnicodeStringTable,
            NumberOfEntries * sizeof (EFI_UNICODE_STRING_TABLE)
            );
       }

       //
       // Allocate space for a copy of the Language specifier
       //
       NewUnicodeStringTable[NumberOfEntries].Language = AllocateCopyPool (3, Language);
       if (NewUnicodeStringTable[NumberOfEntries].Language == NULL) {
         gBS->FreePool (NewUnicodeStringTable);
         return EFI_OUT_OF_RESOURCES;
       }

       //
       // Compute the length of the Unicode String
       //
       for (UnicodeStringLength = 0; UnicodeString[UnicodeStringLength] != 0; UnicodeStringLength++)
         ;

       //
       // Allocate space for a copy of the Unicode String
       //
       NewUnicodeStringTable[NumberOfEntries].UnicodeString = AllocateCopyPool (
                                                               (UnicodeStringLength + 1) * sizeof (CHAR16),
                                                               UnicodeString
                                                               );
       if (NewUnicodeStringTable[NumberOfEntries].UnicodeString == NULL) {
         gBS->FreePool (NewUnicodeStringTable[NumberOfEntries].Language);
         gBS->FreePool (NewUnicodeStringTable);
         return EFI_OUT_OF_RESOURCES;
       }

       //
       // Mark the end of the Unicode String Table
       //
       NewUnicodeStringTable[NumberOfEntries + 1].Language       = NULL;
       NewUnicodeStringTable[NumberOfEntries + 1].UnicodeString  = NULL;

       //
       // Free the old Unicode String Table
       //
       if (*UnicodeStringTable != NULL) {
         gBS->FreePool (*UnicodeStringTable);
       }

       //
       // Point UnicodeStringTable at the newly allocated Unicode String Table
       //
       *UnicodeStringTable = NewUnicodeStringTable;

       return EFI_SUCCESS;
     }

     SupportedLanguages += 3;
   }

   return EFI_UNSUPPORTED;
 }

 /**
   This function frees the table of Unicode strings in UnicodeStringTable.
   If UnicodeStringTable is NULL, then EFI_SUCCESS is returned.
   Otherwise, each language code, and each Unicode string in the Unicode string
   table are freed, and EFI_SUCCESS is returned.

   @param  UnicodeStringTable  A pointer to the table of Unicode strings.

   @retval EFI_SUCCESS         The Unicode string table was freed.

 **/
 EFI_STATUS
 EFIAPI
 FreeUnicodeStringTable (
   IN EFI_UNICODE_STRING_TABLE  *UnicodeStringTable
   )
 {
   UINTN Index;

   //
   // If the Unicode String Table is NULL, then it is already freed
   //
   if (UnicodeStringTable == NULL) {
     return EFI_SUCCESS;
   }

   //
   // Loop through the Unicode String Table until we reach the end of table marker
   //
   for (Index = 0; UnicodeStringTable[Index].Language != NULL; Index++) {

     //
     // Free the Language string from the Unicode String Table
     //
     gBS->FreePool (UnicodeStringTable[Index].Language);

     //
     // Free the Unicode String from the Unicode String Table
     //
     if (UnicodeStringTable[Index].UnicodeString != NULL) {
       gBS->FreePool (UnicodeStringTable[Index].UnicodeString);
     }
   }

   //
   // Free the Unicode String Table itself
   //
   gBS->FreePool (UnicodeStringTable);

   return EFI_SUCCESS;
 }
	/** @file
	Mde UEFI library functions.

	Copyright (c) 2006, Intel Corporation<BR>
	All rights reserved. This program and the accompanying materials
	are licensed and made available under the terms and conditions of the BSD License
	which accompanies this distribution. The full text of the license may be found at
	http://opensource.org/licenses/bsd-license.php

	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

	Module Name: UefiLib.c

	**/

	/**
	Compare whether two names of languages are identical.

	@param Language1 Name of language 1.
	@param Language2 Name of language 2.

	@retval TRUE Language 1 and language 2 are the same.
	@retval FALSE Language 1 and language 2 are not the same.

	**/
	BOOLEAN
	CompareIso639LanguageCode (
	IN CONST CHAR8 *Language1,
	IN CONST CHAR8 *Language2
	)
	{
	return (BOOLEAN) (ReadUnaligned24 ((CONST UINT32 ) Language1) == ReadUnaligned24 ((CONST UINT32 ) Language2));
	}

	/**
	This function searches the list of configuration tables stored in the EFI System
	Table for a table with a GUID that matches TableGuid. If a match is found,
	then a pointer to the configuration table is returned in Table, and EFI_SUCCESS
	is returned. If a matching GUID is not found, then EFI_NOT_FOUND is returned.

	@param TableGuid Pointer to table's GUID type..
	@param Table Pointer to the table associated with TableGuid in the EFI System Table.

	@retval EFI_SUCCESS A configuration table matching TableGuid was found.
	@retval EFI_NOT_FOUND A configuration table matching TableGuid could not be found.

	**/
	EFI_STATUS
	EFIAPI
	EfiGetSystemConfigurationTable (
	IN EFI_GUID *TableGuid,
	OUT VOID **Table
	)
	{
	EFI_SYSTEM_TABLE *SystemTable;
	UINTN Index;

	ASSERT (TableGuid != NULL);
	ASSERT (Table != NULL);

	SystemTable = gST;
	*Table = NULL;
	for (Index = 0; Index < SystemTable->NumberOfTableEntries; Index++) {
	if (CompareGuid (TableGuid, &(SystemTable->ConfigurationTable[Index].VendorGuid))) {
	*Table = SystemTable->ConfigurationTable[Index].VendorTable;
	return EFI_SUCCESS;
	}
	}

	return EFI_NOT_FOUND;
	}

	/**
	This function causes the notification function to be executed for every protocol
	of type ProtocolGuid instance that exists in the system when this function is
	invoked. In addition, every time a protocol of type ProtocolGuid instance is
	installed or reinstalled, the notification function is also executed.

	@param ProtocolGuid Supplies GUID of the protocol upon whose installation the event is fired.
	@param NotifyTpl Supplies the task priority level of the event notifications.
	@param NotifyFunction Supplies the function to notify when the event is signaled.
	@param NotifyContext The context parameter to pass to NotifyFunction.
	@param Registration A pointer to a memory location to receive the registration value.

	@return The notification event that was created.

	**/
	EFI_EVENT
	EFIAPI
	EfiCreateProtocolNotifyEvent(
	IN EFI_GUID *ProtocolGuid,
	IN EFI_TPL NotifyTpl,
	IN EFI_EVENT_NOTIFY NotifyFunction,
	IN VOID *NotifyContext, OPTIONAL
	OUT VOID *Registration
	)
	{
	EFI_STATUS Status;
	EFI_EVENT Event;

	//
	// Create the event
	//

	Status = gBS->CreateEvent (
	EFI_EVENT_NOTIFY_SIGNAL,
	NotifyTpl,
	NotifyFunction,
	NotifyContext,
	&Event
	);
	ASSERT_EFI_ERROR (Status);

	//
	// Register for protocol notifactions on this event
	//

	Status = gBS->RegisterProtocolNotify (
	ProtocolGuid,
	Event,
	Registration
	);

	ASSERT_EFI_ERROR (Status);

	//
	// Kick the event so we will perform an initial pass of
	// current installed drivers
	//

	gBS->SignalEvent (Event);
	return Event;
	}

	/**
	This function creates an event using NotifyTpl, NoifyFunction, and NotifyContext.
	This event is signaled with EfiNamedEventSignal(). This provide the ability for
	one or more listeners on the same event named by the GUID specified by Name.

	@param Name Supplies GUID name of the event.
	@param NotifyTpl Supplies the task priority level of the event notifications.
	@param NotifyFunction Supplies the function to notify when the event is signaled.
	@param NotifyContext The context parameter to pass to NotifyFunction.
	@param Registration A pointer to a memory location to receive the registration value.

	@retval EFI_SUCCESS A named event was created.
	@retval EFI_OUT_OF_RESOURCES There are not enough resource to create the named event.

	**/
	EFI_STATUS
	EFIAPI
	EfiNamedEventListen (
	IN CONST EFI_GUID *Name,
	IN EFI_TPL NotifyTpl,
	IN EFI_EVENT_NOTIFY NotifyFunction,
	IN CONST VOID *NotifyContext, OPTIONAL
	OUT VOID *Registration OPTIONAL
	)
	{
	EFI_STATUS Status;
	EFI_EVENT Event;
	VOID *RegistrationLocal;

	//
	// Create event
	//
	Status = gBS->CreateEvent (
	EFI_EVENT_NOTIFY_SIGNAL,
	NotifyTpl,
	NotifyFunction,
	(VOID *) NotifyContext,
	&Event
	);
	ASSERT_EFI_ERROR (Status);

	//
	// The Registration is not optional to RegisterProtocolNotify().
	// To make it optional to EfiNamedEventListen(), may need to substitute with a local.
	//
	if (Registration != NULL) {
	RegistrationLocal = Registration;
	} else {
	RegistrationLocal = &RegistrationLocal;
	}

	//
	// Register for an installation of protocol interface
	//

	Status = gBS->RegisterProtocolNotify (
	(EFI_GUID *) Name,
	Event,
	RegistrationLocal
	);
	ASSERT_EFI_ERROR (Status);

	return EFI_SUCCESS;
	}

	/**
	This function signals the named event specified by Name. The named event must
	have been created with EfiNamedEventListen().

	@param Name Supplies GUID name of the event.

	@retval EFI_SUCCESS A named event was signaled.
	@retval EFI_OUT_OF_RESOURCES There are not enough resource to signal the named event.

	**/
	EFI_STATUS
	EFIAPI
	EfiNamedEventSignal (
	IN CONST EFI_GUID *Name
	)
	{
	EFI_STATUS Status;
	EFI_HANDLE Handle;

	Handle = NULL;
	Status = gBS->InstallProtocolInterface (
	&Handle,
	(EFI_GUID *) Name,
	EFI_NATIVE_INTERFACE,
	NULL
	);
	ASSERT_EFI_ERROR (Status);

	Status = gBS->UninstallProtocolInterface (
	Handle,
	(EFI_GUID *) Name,
	NULL
	);
	ASSERT_EFI_ERROR (Status);

	return EFI_SUCCESS;
	}


	/**
	This function initializes a basic mutual exclusion lock to the released state
	and returns the lock. Each lock provides mutual exclusion access at its task
	priority level. Since there is no preemption or multiprocessor support in EFI,
	acquiring the lock only consists of raising to the locks TPL.

	@param Lock A pointer to the lock data structure to initialize.
	@param Priority EFI TPL associated with the lock.

	@return The lock.

	**/
	EFI_LOCK *
	EFIAPI
	EfiInitializeLock (
	IN OUT EFI_LOCK *Lock,
	IN EFI_TPL Priority
	)
	{
	ASSERT (Lock != NULL);
	ASSERT (Priority <= EFI_TPL_HIGH_LEVEL);

	Lock->Tpl = Priority;
	Lock->OwnerTpl = EFI_TPL_APPLICATION;
	Lock->Lock = EfiLockReleased ;
	return Lock;
	}

	/**
	This function raises the system¡¯s current task priority level to the task
	priority level of the mutual exclusion lock. Then, it places the lock in the
	acquired state.

	@param Priority The task priority level of the lock.

	**/
	VOID
	EFIAPI
	EfiAcquireLock (
	IN EFI_LOCK *Lock
	)
	{
	ASSERT (Lock != NULL);
	ASSERT (Lock->Lock == EfiLockReleased);

	Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);
	Lock->Lock = EfiLockAcquired;
	}

	/**
	This function raises the system¡¯s current task priority level to the task
	priority level of the mutual exclusion lock. Then, it attempts to place the
	lock in the acquired state.

	@param Lock A pointer to the lock to acquire.

	@retval EFI_SUCCESS The lock was acquired.
	@retval EFI_ACCESS_DENIED The lock could not be acquired because it is already owned.

	**/
	EFI_STATUS
	EFIAPI
	EfiAcquireLockOrFail (
	IN EFI_LOCK *Lock
	)
	{

	ASSERT (Lock != NULL);
	ASSERT (Lock->Lock != EfiLockUninitialized);

	if (Lock->Lock == EfiLockAcquired) {
	//
	// Lock is already owned, so bail out
	//
	return EFI_ACCESS_DENIED;
	}

	Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);

	Lock->Lock = EfiLockAcquired;

	return EFI_SUCCESS;
	}

	/**
	This function transitions a mutual exclusion lock from the acquired state to
	the released state, and restores the system¡¯s task priority level to its
	previous level.

	@param Lock A pointer to the lock to release.

	**/
	VOID
	EFIAPI
	EfiReleaseLock (
	IN EFI_LOCK *Lock
	)
	{
	EFI_TPL Tpl;

	ASSERT (Lock != NULL);
	ASSERT (Lock->Lock == EfiLockAcquired);

	Tpl = Lock->OwnerTpl;

	Lock->Lock = EfiLockReleased;

	gBS->RestoreTPL (Tpl);
	}

	/**
	This function looks up a Unicode string in UnicodeStringTable. If Language is
	a member of SupportedLanguages and a Unicode string is found in UnicodeStringTable
	that matches the language code specified by Language, then it is returned in
	UnicodeString.

	@param Language A pointer to the ISO 639-2 language code for the
	Unicode string to look up and return.
	@param SupportedLanguages A pointer to the set of ISO 639-2 language codes
	that the Unicode string table supports. Language
	must be a member of this set.
	@param UnicodeStringTable A pointer to the table of Unicode strings.
	@param UnicodeString A pointer to the Unicode string from UnicodeStringTable
	that matches the language specified by Language.

	@retval EFI_SUCCESS The Unicode string that matches the language
	specified by Language was found
	in the table of Unicoide strings UnicodeStringTable,
	and it was returned in UnicodeString.
	@retval EFI_INVALID_PARAMETER Language is NULL.
	@retval EFI_INVALID_PARAMETER UnicodeString is NULL.
	@retval EFI_UNSUPPORTED SupportedLanguages is NULL.
	@retval EFI_UNSUPPORTED UnicodeStringTable is NULL.
	@retval EFI_UNSUPPORTED The language specified by Language is not a
	member of SupportedLanguages.
	@retval EFI_UNSUPPORTED The language specified by Language is not
	supported by UnicodeStringTable.

	**/
	EFI_STATUS
	EFIAPI
	LookupUnicodeString (
	IN CONST CHAR8 *Language,
	IN CONST CHAR8 *SupportedLanguages,
	IN CONST EFI_UNICODE_STRING_TABLE *UnicodeStringTable,
	OUT CHAR16 **UnicodeString
	)
	{
	//
	// Make sure the parameters are valid
	//
	if (Language == NULL \|\| UnicodeString == NULL) {
	return EFI_INVALID_PARAMETER;
	}

	//
	// If there are no supported languages, or the Unicode String Table is empty, then the
	// Unicode String specified by Language is not supported by this Unicode String Table
	//
	if (SupportedLanguages == NULL \|\| UnicodeStringTable == NULL) {
	return EFI_UNSUPPORTED;
	}

	//
	// Make sure Language is in the set of Supported Languages
	//
	while (*SupportedLanguages != 0) {
	if (CompareIso639LanguageCode (Language, SupportedLanguages)) {

	//
	// Search the Unicode String Table for the matching Language specifier
	//
	while (UnicodeStringTable->Language != NULL) {
	if (CompareIso639LanguageCode (Language, UnicodeStringTable->Language)) {

	//
	// A matching string was found, so return it
	//
	*UnicodeString = UnicodeStringTable->UnicodeString;
	return EFI_SUCCESS;
	}

	UnicodeStringTable++;
	}

	return EFI_UNSUPPORTED;
	}

	SupportedLanguages += 3;
	}

	return EFI_UNSUPPORTED;
	}

	/**
	This function adds a Unicode string to UnicodeStringTable.
	If Language is a member of SupportedLanguages then UnicodeString is added to
	UnicodeStringTable. New buffers are allocated for both Language and
	UnicodeString. The contents of Language and UnicodeString are copied into
	these new buffers. These buffers are automatically freed when
	FreeUnicodeStringTable() is called.

	@param Language A pointer to the ISO 639-2 language code for the Unicode
	string to add.
	@param SupportedLanguages A pointer to the set of ISO 639-2 language codes
	that the Unicode string table supports.
	Language must be a member of this set.
	@param UnicodeStringTable A pointer to the table of Unicode strings.
	@param UnicodeString A pointer to the Unicode string to add.

	@retval EFI_SUCCESS The Unicode string that matches the language
	specified by Language was found in the table of
	Unicode strings UnicodeStringTable, and it was
	returned in UnicodeString.
	@retval EFI_INVALID_PARAMETER Language is NULL.
	@retval EFI_INVALID_PARAMETER UnicodeString is NULL.
	@retval EFI_INVALID_PARAMETER UnicodeString is an empty string.
	@retval EFI_UNSUPPORTED SupportedLanguages is NULL.
	@retval EFI_ALREADY_STARTED A Unicode string with language Language is
	already present in UnicodeStringTable.
	@retval EFI_OUT_OF_RESOURCES There is not enough memory to add another
	Unicode string to UnicodeStringTable.
	@retval EFI_UNSUPPORTED The language specified by Language is not a
	member of SupportedLanguages.

	**/
	EFI_STATUS
	EFIAPI
	AddUnicodeString (
	IN CONST CHAR8 *Language,
	IN CONST CHAR8 *SupportedLanguages,
	IN EFI_UNICODE_STRING_TABLE **UnicodeStringTable,
	IN CONST CHAR16 *UnicodeString
	)
	{
	UINTN NumberOfEntries;
	EFI_UNICODE_STRING_TABLE *OldUnicodeStringTable;
	EFI_UNICODE_STRING_TABLE *NewUnicodeStringTable;
	UINTN UnicodeStringLength;

	//
	// Make sure the parameter are valid
	//
	if (Language == NULL \|\| UnicodeString == NULL \|\| UnicodeStringTable == NULL) {
	return EFI_INVALID_PARAMETER;
	}

	//
	// If there are no supported languages, then a Unicode String can not be added
	//
	if (SupportedLanguages == NULL) {
	return EFI_UNSUPPORTED;
	}

	//
	// If the Unicode String is empty, then a Unicode String can not be added
	//
	if (UnicodeString[0] == 0) {
	return EFI_INVALID_PARAMETER;
	}

	//
	// Make sure Language is a member of SupportedLanguages
	//
	while (*SupportedLanguages != 0) {
	if (CompareIso639LanguageCode (Language, SupportedLanguages)) {

	//
	// Determine the size of the Unicode String Table by looking for a NULL Language entry
	//
	NumberOfEntries = 0;
	if (*UnicodeStringTable != NULL) {
	OldUnicodeStringTable = *UnicodeStringTable;
	while (OldUnicodeStringTable->Language != NULL) {
	if (CompareIso639LanguageCode (Language, OldUnicodeStringTable->Language)) {
	return EFI_ALREADY_STARTED;
	}

	OldUnicodeStringTable++;
	NumberOfEntries++;
	}
	}

	//
	// Allocate space for a new Unicode String Table. It must hold the current number of
	// entries, plus 1 entry for the new Unicode String, plus 1 entry for the end of table
	// marker
	//
	NewUnicodeStringTable = AllocatePool ((NumberOfEntries + 2) * sizeof (EFI_UNICODE_STRING_TABLE));
	if (NewUnicodeStringTable == NULL) {
	return EFI_OUT_OF_RESOURCES;
	}

	//
	// If the current Unicode String Table contains any entries, then copy them to the
	// newly allocated Unicode String Table.
	//
	if (*UnicodeStringTable != NULL) {
	CopyMem (
	NewUnicodeStringTable,
	*UnicodeStringTable,
	NumberOfEntries * sizeof (EFI_UNICODE_STRING_TABLE)
	);
	}

	//
	// Allocate space for a copy of the Language specifier
	//
	NewUnicodeStringTable[NumberOfEntries].Language = AllocateCopyPool (3, Language);
	if (NewUnicodeStringTable[NumberOfEntries].Language == NULL) {
	gBS->FreePool (NewUnicodeStringTable);
	return EFI_OUT_OF_RESOURCES;
	}

	//
	// Compute the length of the Unicode String
	//
	for (UnicodeStringLength = 0; UnicodeString[UnicodeStringLength] != 0; UnicodeStringLength++)
	;

	//
	// Allocate space for a copy of the Unicode String
	//
	NewUnicodeStringTable[NumberOfEntries].UnicodeString = AllocateCopyPool (
	(UnicodeStringLength + 1) * sizeof (CHAR16),
	UnicodeString
	);
	if (NewUnicodeStringTable[NumberOfEntries].UnicodeString == NULL) {
	gBS->FreePool (NewUnicodeStringTable[NumberOfEntries].Language);
	gBS->FreePool (NewUnicodeStringTable);
	return EFI_OUT_OF_RESOURCES;
	}

	//
	// Mark the end of the Unicode String Table
	//
	NewUnicodeStringTable[NumberOfEntries + 1].Language = NULL;
	NewUnicodeStringTable[NumberOfEntries + 1].UnicodeString = NULL;

	//
	// Free the old Unicode String Table
	//
	if (*UnicodeStringTable != NULL) {
	gBS->FreePool (*UnicodeStringTable);
	}

	//
	// Point UnicodeStringTable at the newly allocated Unicode String Table
	//
	*UnicodeStringTable = NewUnicodeStringTable;

	return EFI_SUCCESS;
	}

	SupportedLanguages += 3;
	}

	return EFI_UNSUPPORTED;
	}

	/**
	This function frees the table of Unicode strings in UnicodeStringTable.
	If UnicodeStringTable is NULL, then EFI_SUCCESS is returned.
	Otherwise, each language code, and each Unicode string in the Unicode string
	table are freed, and EFI_SUCCESS is returned.

	@param UnicodeStringTable A pointer to the table of Unicode strings.

	@retval EFI_SUCCESS The Unicode string table was freed.

	**/
	EFI_STATUS
	EFIAPI
	FreeUnicodeStringTable (
	IN EFI_UNICODE_STRING_TABLE *UnicodeStringTable
	)
	{
	UINTN Index;

	//
	// If the Unicode String Table is NULL, then it is already freed
	//
	if (UnicodeStringTable == NULL) {
	return EFI_SUCCESS;
	}

	//
	// Loop through the Unicode String Table until we reach the end of table marker
	//
	for (Index = 0; UnicodeStringTable[Index].Language != NULL; Index++) {

	//
	// Free the Language string from the Unicode String Table
	//
	gBS->FreePool (UnicodeStringTable[Index].Language);

	//
	// Free the Unicode String from the Unicode String Table
	//
	if (UnicodeStringTable[Index].UnicodeString != NULL) {
	gBS->FreePool (UnicodeStringTable[Index].UnicodeString);
	}
	}

	//
	// Free the Unicode String Table itself
	//
	gBS->FreePool (UnicodeStringTable);

	return EFI_SUCCESS;
	}