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 **/
43 GUID *
44 EFIAPI
CopyGuid(OUT GUID * DestinationGuid,IN CONST GUID * SourceGuid)45 CopyGuid (
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 **/
77 BOOLEAN
78 EFIAPI
CompareGuid(IN CONST GUID * Guid1,IN CONST GUID * Guid2)79 CompareGuid (
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 **/
119 VOID *
120 EFIAPI
ScanGuid(IN CONST VOID * Buffer,IN UINTN Length,IN CONST GUID * Guid)121 ScanGuid (
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 **/
158 BOOLEAN
159 EFIAPI
IsZeroGuid(IN CONST GUID * Guid)160 IsZeroGuid (
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