EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseMemoryLib/MemLibGuid.c

   1 /*++
   2
   3 Copyright (c) 2004 - 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   MemLibGuid.c
  15
  16 Abstract:
  17
  18   Implementation of GUID functions.
  19
  20 --*/
  21
  22 #include "BaseMemoryLibInternal.h"
  23
  24 /**
  25   Copies a source GUID to a destination GUID.
  26
  27   This function copies the contents of the 128-bit GUID specified by SourceGuid to
  28   DestinationGuid, and returns DestinationGuid.
  29   If DestinationGuid is NULL, then ASSERT().
  30   If SourceGuid is NULL, then ASSERT().
  31
  32   @param  DestinationGuid   Pointer to the destination GUID.
  33   @param  SourceGuid        Pointer to the source GUID.
  34
  35   @return DestinationGuid.
  36
  37 **/
  38 GUID *
  39 EFIAPI
  40 CopyGuid (
  41   OUT GUID       *DestinationGuid,
  42   IN CONST GUID  *SourceGuid
  43   )
  44 {
  45   WriteUnaligned64 (
  46     (UINT64*)DestinationGuid,
  47     ReadUnaligned64 ((CONST UINT64*)SourceGuid)
  48     );
  49   WriteUnaligned64 (
  50     (UINT64*)DestinationGuid + 1,
  51     ReadUnaligned64 ((CONST UINT64*)SourceGuid + 1)
  52     );
  53   return DestinationGuid;
  54 }
  55
  56 /**
  57   Compares two GUIDs.
  58
  59   This function compares Guid1 to Guid2.  If the GUIDs are identical then TRUE is returned.
  60   If there are any bit differences in the two GUIDs, then FALSE is returned.
  61   If Guid1 is NULL, then ASSERT().
  62   If Guid2 is NULL, then ASSERT().
  63
  64   @param  Guid1       A pointer to a 128 bit GUID.
  65   @param  Guid2       A pointer to a 128 bit GUID.
  66
  67   @retval TRUE        Guid1 and Guid2 are identical.
  68   @retval FALSE       Guid1 and Guid2 are not identical.
  69
  70 **/
  71 BOOLEAN
  72 EFIAPI
  73 GlueCompareGuid (
  74   IN CONST GUID  *Guid1,
  75   IN CONST GUID  *Guid2
  76   )
  77 {
  78   return (BOOLEAN)(
  79            ReadUnaligned64 ((CONST UINT64*)Guid1)
  80              == ReadUnaligned64 ((CONST UINT64*)Guid2) &&
  81            ReadUnaligned64 ((CONST UINT64*)Guid1 + 1)
  82              == ReadUnaligned64 ((CONST UINT64*)Guid2 + 1)
  83            );
  84 }
  85
  86 /**
  87   Scans a target buffer for a GUID, and returns a pointer to the matching GUID
  88   in the target buffer.
  89
  90   This function searches target the buffer specified by Buffer and Length from
  91   the lowest address to the highest address at 128-bit increments for the 128-bit
  92   GUID value that matches Guid.  If a match is found, then a pointer to the matching
  93   GUID in the target buffer is returned.  If no match is found, then NULL is returned.
  94   If Length is 0, then NULL is returned.
  95   If Length > 0 and Buffer is NULL, then ASSERT().
  96   If Buffer is not aligned on a 32-bit boundary, then ASSERT().
  97   If Length is not aligned on a 128-bit boundary, then ASSERT().
  98   If Length is greater than (MAX_ADDRESS ? Buffer + 1), then ASSERT().
  99
 100   @param  Buffer  Pointer to the target buffer to scan.
 101   @param  Length  Number of bytes in Buffer to scan.
 102   @param  Guid    Value to search for in the target buffer.
 103
 104   @return A pointer to the matching Guid in the target buffer or NULL otherwise.
 105
 106 **/
 107 VOID *
 108 EFIAPI
 109 ScanGuid (
 110   IN CONST VOID  *Buffer,
 111   IN UINTN       Length,
 112   IN CONST GUID  *Guid
 113   )
 114 {
 115   CONST GUID                        *GuidPtr;
 116
 117   ASSERT (((UINTN)Buffer & (sizeof (Guid->Data1) - 1)) == 0);
 118   ASSERT (Length <= (MAX_ADDRESS - (UINTN)Buffer + 1));
 119   ASSERT ((Length & (sizeof (*GuidPtr) - 1)) == 0);
 120
 121   GuidPtr = (GUID*)Buffer;
 122   Buffer  = GuidPtr + Length / sizeof (*GuidPtr);
 123   while (GuidPtr < (CONST GUID*)Buffer) {
 124     if (CompareGuid (GuidPtr, Guid)) {
 125       return (VOID*)GuidPtr;
 126     }
 127     GuidPtr++;
 128   }
 129   return NULL;
 130 }