1/** @file
2  Implementation of GUID functions.
3
4  The following BaseMemoryLib instances contain the same copy of this file:
5
6    BaseMemoryLib
7    BaseMemoryLibMmx
8    BaseMemoryLibSse2
9    BaseMemoryLibRepStr
10    BaseMemoryLibOptDxe
11    BaseMemoryLibOptPei
12    PeiMemoryLib
13    UefiMemoryLib
14
15  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
16  This program and the accompanying materials
17  are licensed and made available under the terms and conditions of the BSD License
18  which accompanies this distribution.  The full text of the license may be found at
19  http://opensource.org/licenses/bsd-license.php.
20
21  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
22  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
23
24**/
25
26#include "MemLibInternals.h"
27
28/**
29  Copies a source GUID to a destination GUID.
30
31  This function copies the contents of the 128-bit GUID specified by SourceGuid to
32  DestinationGuid, and returns DestinationGuid.
33
34  If DestinationGuid is NULL, then ASSERT().
35  If SourceGuid is NULL, then ASSERT().
36
37  @param  DestinationGuid   The pointer to the destination GUID.
38  @param  SourceGuid        The pointer to the source GUID.
39
40  @return DestinationGuid.
41
42**/
43GUID *
44EFIAPI
45CopyGuid (
46  OUT GUID       *DestinationGuid,
47  IN CONST GUID  *SourceGuid
48  )
49{
50  WriteUnaligned64 (
51    (UINT64*)DestinationGuid,
52    ReadUnaligned64 ((CONST UINT64*)SourceGuid)
53    );
54  WriteUnaligned64 (
55    (UINT64*)DestinationGuid + 1,
56    ReadUnaligned64 ((CONST UINT64*)SourceGuid + 1)
57    );
58  return DestinationGuid;
59}
60
61/**
62  Compares two GUIDs.
63
64  This function compares Guid1 to Guid2.  If the GUIDs are identical then TRUE is returned.
65  If there are any bit differences in the two GUIDs, then FALSE is returned.
66
67  If Guid1 is NULL, then ASSERT().
68  If Guid2 is NULL, then ASSERT().
69
70  @param  Guid1       A pointer to a 128 bit GUID.
71  @param  Guid2       A pointer to a 128 bit GUID.
72
73  @retval TRUE        Guid1 and Guid2 are identical.
74  @retval FALSE       Guid1 and Guid2 are not identical.
75
76**/
77BOOLEAN
78EFIAPI
79CompareGuid (
80  IN CONST GUID  *Guid1,
81  IN CONST GUID  *Guid2
82  )
83{
84  UINT64  LowPartOfGuid1;
85  UINT64  LowPartOfGuid2;
86  UINT64  HighPartOfGuid1;
87  UINT64  HighPartOfGuid2;
88
89  LowPartOfGuid1  = ReadUnaligned64 ((CONST UINT64*) Guid1);
90  LowPartOfGuid2  = ReadUnaligned64 ((CONST UINT64*) Guid2);
91  HighPartOfGuid1 = ReadUnaligned64 ((CONST UINT64*) Guid1 + 1);
92  HighPartOfGuid2 = ReadUnaligned64 ((CONST UINT64*) Guid2 + 1);
93
94  return (BOOLEAN) (LowPartOfGuid1 == LowPartOfGuid2 && HighPartOfGuid1 == HighPartOfGuid2);
95}
96
97/**
98  Scans a target buffer for a GUID, and returns a pointer to the matching GUID
99  in the target buffer.
100
101  This function searches the target buffer specified by Buffer and Length from
102  the lowest address to the highest address at 128-bit increments for the 128-bit
103  GUID value that matches Guid.  If a match is found, then a pointer to the matching
104  GUID in the target buffer is returned.  If no match is found, then NULL is returned.
105  If Length is 0, then NULL is returned.
106
107  If Length > 0 and Buffer is NULL, then ASSERT().
108  If Buffer is not aligned on a 32-bit boundary, then ASSERT().
109  If Length is not aligned on a 128-bit boundary, then ASSERT().
110  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
111
112  @param  Buffer  The pointer to the target buffer to scan.
113  @param  Length  The number of bytes in Buffer to scan.
114  @param  Guid    The value to search for in the target buffer.
115
116  @return A pointer to the matching Guid in the target buffer or NULL otherwise.
117
118**/
119VOID *
120EFIAPI
121ScanGuid (
122  IN CONST VOID  *Buffer,
123  IN UINTN       Length,
124  IN CONST GUID  *Guid
125  )
126{
127  CONST GUID                        *GuidPtr;
128
129  ASSERT (((UINTN)Buffer & (sizeof (Guid->Data1) - 1)) == 0);
130  ASSERT (Length <= (MAX_ADDRESS - (UINTN)Buffer + 1));
131  ASSERT ((Length & (sizeof (*GuidPtr) - 1)) == 0);
132
133  GuidPtr = (GUID*)Buffer;
134  Buffer  = GuidPtr + Length / sizeof (*GuidPtr);
135  while (GuidPtr < (CONST GUID*)Buffer) {
136    if (CompareGuid (GuidPtr, Guid)) {
137      return (VOID*)GuidPtr;
138    }
139    GuidPtr++;
140  }
141  return NULL;
142}
143
144/**
145  Checks if the given GUID is a zero GUID.
146
147  This function checks whether the given GUID is a zero GUID. If the GUID is
148  identical to a zero GUID then TRUE is returned. Otherwise, FALSE is returned.
149
150  If Guid is NULL, then ASSERT().
151
152  @param  Guid        The pointer to a 128 bit GUID.
153
154  @retval TRUE        Guid is a zero GUID.
155  @retval FALSE       Guid is not a zero GUID.
156
157**/
158BOOLEAN
159EFIAPI
160IsZeroGuid (
161  IN CONST GUID  *Guid
162  )
163{
164  UINT64  LowPartOfGuid;
165  UINT64  HighPartOfGuid;
166
167  LowPartOfGuid  = ReadUnaligned64 ((CONST UINT64*) Guid);
168  HighPartOfGuid = ReadUnaligned64 ((CONST UINT64*) Guid + 1);
169
170  return (BOOLEAN) (LowPartOfGuid == 0 && HighPartOfGuid == 0);
171}
172