[mirror_edk2.git] / MdePkg / Library / UefiLib / UefiLib.c

/** @file\r
  Mde UEFI library functions.\r
\r
  Copyright (c) 2006 - 2007, Intel Corporation<BR>\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
  Module Name:  UefiLib.c\r
\r
**/\r
\r
/**\r
  Compare whether two names of languages are identical.\r
\r
  @param  Language1 Name of language 1.\r
  @param  Language2 Name of language 2.\r
\r
  @retval TRUE      Language 1 and language 2 are the same.\r
  @retval FALSE     Language 1 and language 2 are not the same.\r
\r
**/\r
STATIC\r
BOOLEAN\r
CompareIso639LanguageCode (\r
  IN CONST CHAR8  *Language1,\r
  IN CONST CHAR8  *Language2\r
  )\r
{\r
  UINT32  Name1;\r
  UINT32  Name2;\r
\r
  Name1 = ReadUnaligned24 ((CONST UINT32 *) Language1);\r
  Name2 = ReadUnaligned24 ((CONST UINT32 *) Language2);\r
\r
  return (BOOLEAN) (Name1 == Name2);\r
}\r
\r
/**\r
  This function searches the list of configuration tables stored in the EFI System \r
  Table for a table with a GUID that matches TableGuid.  If a match is found, \r
  then a pointer to the configuration table is returned in Table, and EFI_SUCCESS \r
  is returned.  If a matching GUID is not found, then EFI_NOT_FOUND is returned.\r
\r
  @param  TableGuid       Pointer to table's GUID type..\r
  @param  Table           Pointer to the table associated with TableGuid in the EFI System Table.\r
\r
  @retval EFI_SUCCESS     A configuration table matching TableGuid was found.\r
  @retval EFI_NOT_FOUND   A configuration table matching TableGuid could not be found.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
EfiGetSystemConfigurationTable (  \r
  IN  EFI_GUID  *TableGuid,\r
  OUT VOID      **Table\r
  )\r
{\r
  EFI_SYSTEM_TABLE  *SystemTable;\r
  UINTN             Index;\r
\r
  ASSERT (TableGuid != NULL);\r
  ASSERT (Table != NULL);\r
\r
  SystemTable = gST;\r
  *Table = NULL;\r
  for (Index = 0; Index < SystemTable->NumberOfTableEntries; Index++) {\r
    if (CompareGuid (TableGuid, &(SystemTable->ConfigurationTable[Index].VendorGuid))) {\r
      *Table = SystemTable->ConfigurationTable[Index].VendorTable;\r
      return EFI_SUCCESS;\r
    }\r
  }\r
\r
  return EFI_NOT_FOUND;\r
}\r
\r
/**\r
  This function causes the notification function to be executed for every protocol \r
  of type ProtocolGuid instance that exists in the system when this function is \r
  invoked.  In addition, every time a protocol of type ProtocolGuid instance is \r
  installed or reinstalled, the notification function is also executed.\r
\r
  @param  ProtocolGuid    Supplies GUID of the protocol upon whose installation the event is fired.\r
  @param  NotifyTpl       Supplies the task priority level of the event notifications.\r
  @param  NotifyFunction  Supplies the function to notify when the event is signaled.\r
  @param  NotifyContext   The context parameter to pass to NotifyFunction.\r
  @param  Registration    A pointer to a memory location to receive the registration value.\r
\r
  @return The notification event that was created. \r
\r
**/\r
EFI_EVENT\r
EFIAPI\r
EfiCreateProtocolNotifyEvent(\r
  IN  EFI_GUID          *ProtocolGuid,\r
  IN  EFI_TPL           NotifyTpl,\r
  IN  EFI_EVENT_NOTIFY  NotifyFunction,\r
  IN  VOID              *NotifyContext,  OPTIONAL\r
  OUT VOID              **Registration\r
  )\r
{\r
  EFI_STATUS  Status;\r
  EFI_EVENT   Event;\r
\r
  //\r
  // Create the event\r
  //\r
\r
  Status = gBS->CreateEvent (\r
                  EFI_EVENT_NOTIFY_SIGNAL,\r
                  NotifyTpl,\r
                  NotifyFunction,\r
                  NotifyContext,\r
                  &Event\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Register for protocol notifactions on this event\r
  //\r
\r
  Status = gBS->RegisterProtocolNotify (\r
                  ProtocolGuid,\r
                  Event,\r
                  Registration\r
                  );\r
\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Kick the event so we will perform an initial pass of\r
  // current installed drivers\r
  //\r
\r
  gBS->SignalEvent (Event);\r
  return Event;\r
}\r
\r
/**\r
  This function creates an event using NotifyTpl, NoifyFunction, and NotifyContext.\r
  This event is signaled with EfiNamedEventSignal().  This provide the ability for \r
  one or more listeners on the same event named by the GUID specified by Name.\r
\r
  @param  Name                  Supplies GUID name of the event.\r
  @param  NotifyTpl             Supplies the task priority level of the event notifications.\r
  @param  NotifyFunction        Supplies the function to notify when the event is signaled.\r
  @param  NotifyContext         The context parameter to pass to NotifyFunction. \r
  @param  Registration          A pointer to a memory location to receive the registration value.\r
\r
  @retval EFI_SUCCESS           A named event was created.\r
  @retval EFI_OUT_OF_RESOURCES  There are not enough resource to create the named event.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
EfiNamedEventListen (\r
  IN CONST EFI_GUID    *Name,\r
  IN EFI_TPL           NotifyTpl,\r
  IN EFI_EVENT_NOTIFY  NotifyFunction,\r
  IN CONST VOID        *NotifyContext,  OPTIONAL\r
  OUT VOID             *Registration OPTIONAL\r
  )\r
{\r
  EFI_STATUS  Status;\r
  EFI_EVENT   Event;\r
  VOID        *RegistrationLocal;\r
\r
  //\r
  // Create event\r
  //\r
  Status = gBS->CreateEvent (\r
                  EFI_EVENT_NOTIFY_SIGNAL,\r
                  NotifyTpl,\r
                  NotifyFunction,\r
                  (VOID *) NotifyContext,\r
                  &Event\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // The Registration is not optional to RegisterProtocolNotify().\r
  // To make it optional to EfiNamedEventListen(), may need to substitute with a local.\r
  //\r
  if (Registration != NULL) {\r
    RegistrationLocal = Registration;\r
  } else {\r
    RegistrationLocal = &RegistrationLocal;\r
  }\r
\r
  //\r
  // Register for an installation of protocol interface\r
  //\r
\r
  Status = gBS->RegisterProtocolNotify (\r
                  (EFI_GUID *) Name,\r
                  Event,\r
                  RegistrationLocal\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  This function signals the named event specified by Name.  The named event must \r
  have been created with EfiNamedEventListen().\r
\r
  @param  Name                  Supplies GUID name of the event.\r
\r
  @retval EFI_SUCCESS           A named event was signaled.\r
  @retval EFI_OUT_OF_RESOURCES  There are not enough resource to signal the named event.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
EfiNamedEventSignal (\r
  IN CONST EFI_GUID  *Name\r
  )\r
{\r
  EFI_STATUS  Status;\r
  EFI_HANDLE  Handle;\r
\r
  Handle = NULL;\r
  Status = gBS->InstallProtocolInterface (\r
                  &Handle,\r
                  (EFI_GUID *) Name,\r
                  EFI_NATIVE_INTERFACE,\r
                  NULL\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  Status = gBS->UninstallProtocolInterface (\r
                  Handle,\r
                  (EFI_GUID *) Name,\r
                  NULL\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
\r
/**\r
  This function initializes a basic mutual exclusion lock to the released state \r
  and returns the lock.  Each lock provides mutual exclusion access at its task \r
  priority level.  Since there is no preemption or multiprocessor support in EFI,\r
  acquiring the lock only consists of raising to the locks TPL.\r
\r
  @param  Lock       A pointer to the lock data structure to initialize.\r
  @param  Priority   EFI TPL associated with the lock.\r
\r
  @return The lock.\r
\r
**/\r
EFI_LOCK *\r
EFIAPI\r
EfiInitializeLock (\r
  IN OUT EFI_LOCK  *Lock,\r
  IN EFI_TPL        Priority\r
  )\r
{\r
  ASSERT (Lock != NULL);\r
  ASSERT (Priority <= EFI_TPL_HIGH_LEVEL);\r
\r
  Lock->Tpl       = Priority;\r
  Lock->OwnerTpl  = EFI_TPL_APPLICATION;\r
  Lock->Lock      = EfiLockReleased ;\r
  return Lock;\r
}\r
\r
/**\r
  This function raises the system's current task priority level to the task \r
  priority level of the mutual exclusion lock.  Then, it places the lock in the \r
  acquired state.\r
\r
  @param  Priority  The task priority level of the lock.\r
\r
**/\r
VOID\r
EFIAPI\r
EfiAcquireLock (\r
  IN EFI_LOCK  *Lock\r
  )\r
{\r
  ASSERT (Lock != NULL);\r
  ASSERT (Lock->Lock == EfiLockReleased);\r
\r
  Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);\r
  Lock->Lock     = EfiLockAcquired;\r
}\r
\r
/**\r
  This function raises the system's current task priority level to the task \r
  priority level of the mutual exclusion lock.  Then, it attempts to place the \r
  lock in the acquired state.\r
\r
  @param  Lock              A pointer to the lock to acquire.\r
\r
  @retval EFI_SUCCESS       The lock was acquired.\r
  @retval EFI_ACCESS_DENIED The lock could not be acquired because it is already owned.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
EfiAcquireLockOrFail (\r
  IN EFI_LOCK  *Lock\r
  )\r
{\r
\r
  ASSERT (Lock != NULL);\r
  ASSERT (Lock->Lock != EfiLockUninitialized);\r
\r
  if (Lock->Lock == EfiLockAcquired) {\r
    //\r
    // Lock is already owned, so bail out\r
    //\r
    return EFI_ACCESS_DENIED;\r
  }\r
\r
  Lock->OwnerTpl = gBS->RaiseTPL (Lock->Tpl);\r
\r
  Lock->Lock = EfiLockAcquired;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  This function transitions a mutual exclusion lock from the acquired state to \r
  the released state, and restores the system's task priority level to its \r
  previous level.\r
\r
  @param  Lock  A pointer to the lock to release.\r
\r
**/\r
VOID\r
EFIAPI\r
EfiReleaseLock (\r
  IN EFI_LOCK  *Lock\r
  )\r
{\r
  EFI_TPL Tpl;\r
\r
  ASSERT (Lock != NULL);\r
  ASSERT (Lock->Lock == EfiLockAcquired);\r
\r
  Tpl = Lock->OwnerTpl;\r
  \r
  Lock->Lock = EfiLockReleased;\r
\r
  gBS->RestoreTPL (Tpl);\r
}\r
\r
/**
  Tests whether a controller is managed by a specific driver.

  This function tests whether a specific driver manages ControllerHandle by\r
  opening on DriverBindingHandle a protocol specified by ProtocolGuid with\r
  attribute EFI_OPEN_PROTOCOL_BY_DRIVER.  This library function is used to\r
  implement the Component Name Protocol for EFI Drivers.\r
  If ProtocolGuid is NULL, then ASSERT().\r

  @param  ControllerHandle     A handle for a controller to test.
  @param  DriverBindingHandle  Specifies the driver binding handle for the
                               driver.
  @param  ProtocolGuid         Supplies GUID for the protocol opened by the
                               driver on the controller. 

  @retval EFI_SUCCESS          ControllerHandle is managed by the specific
                               driver.
  @retval EFI_UNSUPPORTED      ControllerHandle is not managed by the specific
                               driver.

**/\r
EFI_STATUS\r
EFIAPI\r
EfiTestManagedDevice (\r
  IN CONST EFI_HANDLE       ControllerHandle,\r
  IN CONST EFI_HANDLE       DriverBindingHandle,\r
  IN CONST EFI_GUID         *ProtocolGuid\r
  )\r
{\r
  EFI_STATUS     Status;\r
  VOID           *ManagedInterface;\r
\r
  ASSERT (ProtocolGuid != NULL);\r
\r
  Status = gBS->OpenProtocol (\r
                  ControllerHandle,\r
                  (EFI_GUID *) ProtocolGuid,\r
                  &ManagedInterface,\r
                  DriverBindingHandle,\r
                  ControllerHandle,\r
                  EFI_OPEN_PROTOCOL_BY_DRIVER\r
                  );\r
  if (!EFI_ERROR (Status)) {\r
    gBS->CloseProtocol (\r
           ControllerHandle,\r
           (EFI_GUID *) ProtocolGuid,\r
           DriverBindingHandle,\r
           ControllerHandle\r
           );\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  if (Status != EFI_ALREADY_STARTED) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**
  Tests whether a child handle is a children device of the controller.

  This function tests whether ChildHandle is one of the children of
  ControllerHandle which are consuming a protocol specified by ProtocolGuid
  with the attribute bit EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER set.  This
  library function is used to implement the Component Name Protocol for EFI
  Drivers.
  If ProtocolGuid is NULL, then ASSERT().

  @param  ControllerHandle     A handle for a (parent) controller to test. 
  @param  ChildHandle          A child handle to test.
  @param  ConsumsedGuid        Supplies GUID for the protocol consumed by
                               children from controller. 

  @retval EFI_SUCCESS          ChildHandle is a child of the ControllerHandle.
  @retval EFI_UNSUPPORTED      ChildHandle is not a child of the
                               ControllerHandle.

**/\r
EFI_STATUS\r
EFIAPI\r
EfiTestChildHandle (\r
  IN CONST EFI_HANDLE       ControllerHandle,\r
  IN CONST EFI_HANDLE       ChildHandle,\r
  IN CONST EFI_GUID         *ProtocolGuid\r
  )\r
{\r
  EFI_STATUS                            Status;\r
  EFI_OPEN_PROTOCOL_INFORMATION_ENTRY   *OpenInfoBuffer;\r
  UINTN                                 EntryCount;\r
  UINTN                                 Index;\r
\r
  ASSERT (ProtocolGuid != NULL);\r
\r
  //\r
  // Retrieve the list of agents that are consuming the specific protocol\r
  // on ControllerHandle.\r
  //\r
  Status = gBS->OpenProtocolInformation (\r
                  ControllerHandle,\r
                  (EFI_GUID *) ProtocolGuid,\r
                  &OpenInfoBuffer,\r
                  &EntryCount\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  //\r
  // Inspect if ChildHandle is one of the agents.\r
  //\r
  Status = EFI_UNSUPPORTED;\r
  for (Index = 0; Index < EntryCount; Index++) {\r
    if ((OpenInfoBuffer[Index].ControllerHandle == ChildHandle) &&\r
        (OpenInfoBuffer[Index].Attributes & EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER) != 0) {\r
      Status = EFI_SUCCESS;\r
      break;\r
    }\r
  }\r
  \r
  FreePool (OpenInfoBuffer);\r
  return Status;\r
}\r
\r
/**\r
  This function looks up a Unicode string in UnicodeStringTable.  If Language is \r
  a member of SupportedLanguages and a Unicode string is found in UnicodeStringTable\r
  that matches the language code specified by Language, then it is returned in \r
  UnicodeString.\r
\r
  @param  Language                A pointer to the ISO 639-2 language code for the \r
                                  Unicode string to look up and return.\r
  @param  SupportedLanguages      A pointer to the set of ISO 639-2 language codes \r
                                  that the Unicode string table supports.  Language \r
                                  must be a member of this set.\r
  @param  UnicodeStringTable      A pointer to the table of Unicode strings.\r
  @param  UnicodeString           A pointer to the Unicode string from UnicodeStringTable\r
                                  that matches the language specified by Language.\r
\r
  @retval  EFI_SUCCESS            The Unicode string that matches the language \r
                                  specified by Language was found\r
                                  in the table of Unicoide strings UnicodeStringTable, \r
                                  and it was returned in UnicodeString.\r
  @retval  EFI_INVALID_PARAMETER  Language is NULL.\r
  @retval  EFI_INVALID_PARAMETER  UnicodeString is NULL.\r
  @retval  EFI_UNSUPPORTED        SupportedLanguages is NULL.\r
  @retval  EFI_UNSUPPORTED        UnicodeStringTable is NULL.\r
  @retval  EFI_UNSUPPORTED        The language specified by Language is not a \r
                                  member of SupportedLanguages.\r
  @retval  EFI_UNSUPPORTED        The language specified by Language is not \r
                                  supported by UnicodeStringTable.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
LookupUnicodeString (\r
  IN CONST CHAR8                     *Language,\r
  IN CONST CHAR8                     *SupportedLanguages,\r
  IN CONST EFI_UNICODE_STRING_TABLE  *UnicodeStringTable,\r
  OUT CHAR16                         **UnicodeString\r
  )\r
{\r
  //\r
  // Make sure the parameters are valid\r
  //\r
  if (Language == NULL || UnicodeString == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // If there are no supported languages, or the Unicode String Table is empty, then the\r
  // Unicode String specified by Language is not supported by this Unicode String Table\r
  //\r
  if (SupportedLanguages == NULL || UnicodeStringTable == NULL) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  //\r
  // Make sure Language is in the set of Supported Languages\r
  //\r
  while (*SupportedLanguages != 0) {\r
    if (CompareIso639LanguageCode (Language, SupportedLanguages)) {\r
\r
      //\r
      // Search the Unicode String Table for the matching Language specifier\r
      //\r
      while (UnicodeStringTable->Language != NULL) {\r
        if (CompareIso639LanguageCode (Language, UnicodeStringTable->Language)) {\r
\r
          //\r
          // A matching string was found, so return it\r
          //\r
          *UnicodeString = UnicodeStringTable->UnicodeString;\r
          return EFI_SUCCESS;\r
        }\r
\r
        UnicodeStringTable++;\r
      }\r
\r
      return EFI_UNSUPPORTED;\r
    }\r
\r
    SupportedLanguages += 3;\r
  }\r
\r
  return EFI_UNSUPPORTED;\r
}\r
\r
/**\r
  This function adds a Unicode string to UnicodeStringTable.\r
  If Language is a member of SupportedLanguages then UnicodeString is added to \r
  UnicodeStringTable.  New buffers are allocated for both Language and \r
  UnicodeString.  The contents of Language and UnicodeString are copied into \r
  these new buffers.  These buffers are automatically freed when \r
  FreeUnicodeStringTable() is called.\r
\r
  @param  Language                A pointer to the ISO 639-2 language code for the Unicode \r
                                  string to add.\r
  @param  SupportedLanguages      A pointer to the set of ISO 639-2 language codes\r
                                  that the Unicode string table supports.\r
                                  Language must be a member of this set.\r
  @param  UnicodeStringTable      A pointer to the table of Unicode strings.\r
  @param  UnicodeString           A pointer to the Unicode string to add.\r
\r
  @retval EFI_SUCCESS             The Unicode string that matches the language \r
                                  specified by Language was found in the table of \r
                                  Unicode strings UnicodeStringTable, and it was \r
                                  returned in UnicodeString.\r
  @retval EFI_INVALID_PARAMETER   Language is NULL.\r
  @retval EFI_INVALID_PARAMETER   UnicodeString is NULL.\r
  @retval EFI_INVALID_PARAMETER   UnicodeString is an empty string.\r
  @retval EFI_UNSUPPORTED         SupportedLanguages is NULL.\r
  @retval EFI_ALREADY_STARTED     A Unicode string with language Language is \r
                                  already present in UnicodeStringTable.\r
  @retval EFI_OUT_OF_RESOURCES    There is not enough memory to add another \r
                                  Unicode string to UnicodeStringTable.\r
  @retval EFI_UNSUPPORTED         The language specified by Language is not a \r
                                  member of SupportedLanguages.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
AddUnicodeString (\r
  IN CONST CHAR8               *Language,\r
  IN CONST CHAR8               *SupportedLanguages,\r
  IN EFI_UNICODE_STRING_TABLE  **UnicodeStringTable,\r
  IN CONST CHAR16              *UnicodeString\r
  )\r
{\r
  UINTN                     NumberOfEntries;\r
  EFI_UNICODE_STRING_TABLE  *OldUnicodeStringTable;\r
  EFI_UNICODE_STRING_TABLE  *NewUnicodeStringTable;\r
  UINTN                     UnicodeStringLength;\r
\r
  //\r
  // Make sure the parameter are valid\r
  //\r
  if (Language == NULL || UnicodeString == NULL || UnicodeStringTable == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // If there are no supported languages, then a Unicode String can not be added\r
  //\r
  if (SupportedLanguages == NULL) {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  //\r
  // If the Unicode String is empty, then a Unicode String can not be added\r
  //\r
  if (UnicodeString[0] == 0) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  //\r
  // Make sure Language is a member of SupportedLanguages\r
  //\r
  while (*SupportedLanguages != 0) {\r
    if (CompareIso639LanguageCode (Language, SupportedLanguages)) {\r
\r
      //\r
      // Determine the size of the Unicode String Table by looking for a NULL Language entry\r
      //\r
      NumberOfEntries = 0;\r
      if (*UnicodeStringTable != NULL) {\r
        OldUnicodeStringTable = *UnicodeStringTable;\r
        while (OldUnicodeStringTable->Language != NULL) {\r
          if (CompareIso639LanguageCode (Language, OldUnicodeStringTable->Language)) {\r
            return EFI_ALREADY_STARTED;\r
          }\r
\r
          OldUnicodeStringTable++;\r
          NumberOfEntries++;\r
        }\r
      }\r
\r
      //\r
      // Allocate space for a new Unicode String Table.  It must hold the current number of\r
      // entries, plus 1 entry for the new Unicode String, plus 1 entry for the end of table\r
      // marker\r
      //\r
      NewUnicodeStringTable = AllocatePool ((NumberOfEntries + 2) * sizeof (EFI_UNICODE_STRING_TABLE));\r
      if (NewUnicodeStringTable == NULL) {\r
        return EFI_OUT_OF_RESOURCES;\r
      }\r
\r
      //\r
      // If the current Unicode String Table contains any entries, then copy them to the\r
      // newly allocated Unicode String Table.\r
      //\r
      if (*UnicodeStringTable != NULL) {\r
        CopyMem (\r
           NewUnicodeStringTable,\r
           *UnicodeStringTable,\r
           NumberOfEntries * sizeof (EFI_UNICODE_STRING_TABLE)\r
           );\r
      }\r
\r
      //\r
      // Allocate space for a copy of the Language specifier\r
      //\r
      NewUnicodeStringTable[NumberOfEntries].Language = AllocateCopyPool (3, Language);\r
      if (NewUnicodeStringTable[NumberOfEntries].Language == NULL) {\r
        gBS->FreePool (NewUnicodeStringTable);\r
        return EFI_OUT_OF_RESOURCES;\r
      }\r
\r
      //\r
      // Compute the length of the Unicode String\r
      //\r
      for (UnicodeStringLength = 0; UnicodeString[UnicodeStringLength] != 0; UnicodeStringLength++)\r
        ;\r
\r
      //\r
      // Allocate space for a copy of the Unicode String\r
      //\r
      NewUnicodeStringTable[NumberOfEntries].UnicodeString = AllocateCopyPool (\r
                                                              (UnicodeStringLength + 1) * sizeof (CHAR16),\r
                                                              UnicodeString\r
                                                              );\r
      if (NewUnicodeStringTable[NumberOfEntries].UnicodeString == NULL) {\r
        gBS->FreePool (NewUnicodeStringTable[NumberOfEntries].Language);\r
        gBS->FreePool (NewUnicodeStringTable);\r
        return EFI_OUT_OF_RESOURCES;\r
      }\r
\r
      //\r
      // Mark the end of the Unicode String Table\r
      //\r
      NewUnicodeStringTable[NumberOfEntries + 1].Language       = NULL;\r
      NewUnicodeStringTable[NumberOfEntries + 1].UnicodeString  = NULL;\r
\r
      //\r
      // Free the old Unicode String Table\r
      //\r
      if (*UnicodeStringTable != NULL) {\r
        gBS->FreePool (*UnicodeStringTable);\r
      }\r
\r
      //\r
      // Point UnicodeStringTable at the newly allocated Unicode String Table\r
      //\r
      *UnicodeStringTable = NewUnicodeStringTable;\r
\r
      return EFI_SUCCESS;\r
    }\r
\r
    SupportedLanguages += 3;\r
  }\r
\r
  return EFI_UNSUPPORTED;\r
}\r
\r
/**\r
  This function frees the table of Unicode strings in UnicodeStringTable.\r
  If UnicodeStringTable is NULL, then EFI_SUCCESS is returned.\r
  Otherwise, each language code, and each Unicode string in the Unicode string \r
  table are freed, and EFI_SUCCESS is returned.\r
\r
  @param  UnicodeStringTable  A pointer to the table of Unicode strings.\r
\r
  @retval EFI_SUCCESS         The Unicode string table was freed.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
FreeUnicodeStringTable (\r
  IN EFI_UNICODE_STRING_TABLE  *UnicodeStringTable\r
  )\r
{\r
  UINTN Index;\r
\r
  //\r
  // If the Unicode String Table is NULL, then it is already freed\r
  //\r
  if (UnicodeStringTable == NULL) {\r
    return EFI_SUCCESS;\r
  }\r
\r
  //\r
  // Loop through the Unicode String Table until we reach the end of table marker\r
  //\r
  for (Index = 0; UnicodeStringTable[Index].Language != NULL; Index++) {\r
\r
    //\r
    // Free the Language string from the Unicode String Table\r
    //\r
    gBS->FreePool (UnicodeStringTable[Index].Language);\r
\r
    //\r
    // Free the Unicode String from the Unicode String Table\r
    //\r
    if (UnicodeStringTable[Index].UnicodeString != NULL) {\r
      gBS->FreePool (UnicodeStringTable[Index].UnicodeString);\r
    }\r
  }\r
\r
  //\r
  // Free the Unicode String Table itself\r
  //\r
  gBS->FreePool (UnicodeStringTable);\r
\r
  return EFI_SUCCESS;\r
}\r