1 /** @file
2   Architecture Independent Base Memory Library Implementation.
3 
4   The following BaseMemoryLib instances contain the same copy of this file:
5     BaseMemoryLib
6     PeiMemoryLib
7     UefiMemoryLib
8 
9   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
10   This program and the accompanying materials
11   are licensed and made available under the terms and conditions of the BSD License
12   which accompanies this distribution.  The full text of the license may be found at
13   http://opensource.org/licenses/bsd-license.php.
14 
15   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
16   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
17 
18 **/
19 
20 #include "MemLibInternals.h"
21 
22 /**
23   Fills a target buffer with a 16-bit value, and returns the target buffer.
24 
25   @param  Buffer  The pointer to the target buffer to fill.
26   @param  Length  The count of 16-bit value to fill.
27   @param  Value   The value with which to fill Length bytes of Buffer.
28 
29   @return Buffer
30 
31 **/
32 VOID *
33 EFIAPI
InternalMemSetMem16(OUT VOID * Buffer,IN UINTN Length,IN UINT16 Value)34 InternalMemSetMem16 (
35   OUT     VOID                      *Buffer,
36   IN      UINTN                     Length,
37   IN      UINT16                    Value
38   )
39 {
40   do {
41     ((UINT16*)Buffer)[--Length] = Value;
42   } while (Length != 0);
43   return Buffer;
44 }
45 
46 /**
47   Fills a target buffer with a 32-bit value, and returns the target buffer.
48 
49   @param  Buffer  The pointer to the target buffer to fill.
50   @param  Length  The count of 32-bit value to fill.
51   @param  Value   The value with which to fill Length bytes of Buffer.
52 
53   @return Buffer
54 
55 **/
56 VOID *
57 EFIAPI
InternalMemSetMem32(OUT VOID * Buffer,IN UINTN Length,IN UINT32 Value)58 InternalMemSetMem32 (
59   OUT     VOID                      *Buffer,
60   IN      UINTN                     Length,
61   IN      UINT32                    Value
62   )
63 {
64   do {
65     ((UINT32*)Buffer)[--Length] = Value;
66   } while (Length != 0);
67   return Buffer;
68 }
69 
70 /**
71   Fills a target buffer with a 64-bit value, and returns the target buffer.
72 
73   @param  Buffer  The pointer to the target buffer to fill.
74   @param  Length  The count of 64-bit value to fill.
75   @param  Value   The value with which to fill Length bytes of Buffer.
76 
77   @return Buffer
78 
79 **/
80 VOID *
81 EFIAPI
InternalMemSetMem64(OUT VOID * Buffer,IN UINTN Length,IN UINT64 Value)82 InternalMemSetMem64 (
83   OUT     VOID                      *Buffer,
84   IN      UINTN                     Length,
85   IN      UINT64                    Value
86   )
87 {
88   do {
89     ((UINT64*)Buffer)[--Length] = Value;
90   } while (Length != 0);
91   return Buffer;
92 }
93 
94 /**
95   Set Buffer to 0 for Size bytes.
96 
97   @param  Buffer Memory to set.
98   @param  Length The number of bytes to set
99 
100   @return Buffer
101 
102 **/
103 VOID *
104 EFIAPI
InternalMemZeroMem(OUT VOID * Buffer,IN UINTN Length)105 InternalMemZeroMem (
106   OUT     VOID                      *Buffer,
107   IN      UINTN                     Length
108   )
109 {
110   return InternalMemSetMem (Buffer, Length, 0);
111 }
112 
113 /**
114   Compares two memory buffers of a given length.
115 
116   @param  DestinationBuffer The first memory buffer
117   @param  SourceBuffer      The second memory buffer
118   @param  Length            The length of DestinationBuffer and SourceBuffer memory
119                             regions to compare. Must be non-zero.
120 
121   @return 0                 All Length bytes of the two buffers are identical.
122   @retval Non-zero          The first mismatched byte in SourceBuffer subtracted from the first
123                             mismatched byte in DestinationBuffer.
124 
125 **/
126 INTN
127 EFIAPI
InternalMemCompareMem(IN CONST VOID * DestinationBuffer,IN CONST VOID * SourceBuffer,IN UINTN Length)128 InternalMemCompareMem (
129   IN      CONST VOID                *DestinationBuffer,
130   IN      CONST VOID                *SourceBuffer,
131   IN      UINTN                     Length
132   )
133 {
134   while ((--Length != 0) &&
135          (*(INT8*)DestinationBuffer == *(INT8*)SourceBuffer)) {
136     DestinationBuffer = (INT8*)DestinationBuffer + 1;
137     SourceBuffer = (INT8*)SourceBuffer + 1;
138   }
139   return (INTN)*(UINT8*)DestinationBuffer - (INTN)*(UINT8*)SourceBuffer;
140 }
141 
142 /**
143   Scans a target buffer for an 8-bit value, and returns a pointer to the
144   matching 8-bit value in the target buffer.
145 
146   @param  Buffer  The pointer to the target buffer to scan.
147   @param  Length  The count of 8-bit value to scan. Must be non-zero.
148   @param  Value   The value to search for in the target buffer.
149 
150   @return The pointer to the first occurrence or NULL if not found.
151 
152 **/
153 CONST VOID *
154 EFIAPI
InternalMemScanMem8(IN CONST VOID * Buffer,IN UINTN Length,IN UINT8 Value)155 InternalMemScanMem8 (
156   IN      CONST VOID                *Buffer,
157   IN      UINTN                     Length,
158   IN      UINT8                     Value
159   )
160 {
161   CONST UINT8                       *Pointer;
162 
163   Pointer = (CONST UINT8*)Buffer;
164   do {
165     if (*(Pointer++) == Value) {
166       return --Pointer;
167     }
168   } while (--Length != 0);
169   return NULL;
170 }
171 
172 /**
173   Scans a target buffer for a 16-bit value, and returns a pointer to the
174   matching 16-bit value in the target buffer.
175 
176   @param  Buffer  The pointer to the target buffer to scan.
177   @param  Length  The count of 16-bit value to scan. Must be non-zero.
178   @param  Value   The value to search for in the target buffer.
179 
180   @return The pointer to the first occurrence or NULL if not found.
181 
182 **/
183 CONST VOID *
184 EFIAPI
InternalMemScanMem16(IN CONST VOID * Buffer,IN UINTN Length,IN UINT16 Value)185 InternalMemScanMem16 (
186   IN      CONST VOID                *Buffer,
187   IN      UINTN                     Length,
188   IN      UINT16                    Value
189   )
190 {
191   CONST UINT16                      *Pointer;
192 
193   Pointer = (CONST UINT16*)Buffer;
194   do {
195     if (*(Pointer++) == Value) {
196       return --Pointer;
197     }
198   } while (--Length != 0);
199   return NULL;
200 }
201 
202 /**
203   Scans a target buffer for a 32-bit value, and returns a pointer to the
204   matching 32-bit value in the target buffer.
205 
206   @param  Buffer  The pointer to the target buffer to scan.
207   @param  Length  The count of 32-bit value to scan. Must be non-zero.
208   @param  Value   The value to search for in the target buffer.
209 
210   @return The pointer to the first occurrence or NULL if not found.
211 
212 **/
213 CONST VOID *
214 EFIAPI
InternalMemScanMem32(IN CONST VOID * Buffer,IN UINTN Length,IN UINT32 Value)215 InternalMemScanMem32 (
216   IN      CONST VOID                *Buffer,
217   IN      UINTN                     Length,
218   IN      UINT32                    Value
219   )
220 {
221   CONST UINT32                      *Pointer;
222 
223   Pointer = (CONST UINT32*)Buffer;
224   do {
225     if (*(Pointer++) == Value) {
226       return --Pointer;
227     }
228   } while (--Length != 0);
229   return NULL;
230 }
231 
232 /**
233   Scans a target buffer for a 64-bit value, and returns a pointer to the
234   matching 64-bit value in the target buffer.
235 
236   @param  Buffer  The pointer to the target buffer to scan.
237   @param  Length  The count of 64-bit value to scan. Must be non-zero.
238   @param  Value   The value to search for in the target buffer.
239 
240   @return The pointer to the first occurrence or NULL if not found.
241 
242 **/
243 CONST VOID *
244 EFIAPI
InternalMemScanMem64(IN CONST VOID * Buffer,IN UINTN Length,IN UINT64 Value)245 InternalMemScanMem64 (
246   IN      CONST VOID                *Buffer,
247   IN      UINTN                     Length,
248   IN      UINT64                    Value
249   )
250 {
251   CONST UINT64                      *Pointer;
252 
253   Pointer = (CONST UINT64*)Buffer;
254   do {
255     if (*(Pointer++) == Value) {
256       return --Pointer;
257     }
258   } while (--Length != 0);
259   return NULL;
260 }
261