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 - 2016, 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 34 InternalMemSetMem16 ( 35 OUT VOID *Buffer, 36 IN UINTN Length, 37 IN UINT16 Value 38 ) 39 { 40 for (; Length != 0; Length--) { 41 ((UINT16*)Buffer)[Length - 1] = Value; 42 } 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 58 InternalMemSetMem32 ( 59 OUT VOID *Buffer, 60 IN UINTN Length, 61 IN UINT32 Value 62 ) 63 { 64 for (; Length != 0; Length--) { 65 ((UINT32*)Buffer)[Length - 1] = Value; 66 } 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 82 InternalMemSetMem64 ( 83 OUT VOID *Buffer, 84 IN UINTN Length, 85 IN UINT64 Value 86 ) 87 { 88 for (; Length != 0; Length--) { 89 ((UINT64*)Buffer)[Length - 1] = Value; 90 } 91 return Buffer; 92 } 93 94 /** 95 Set Buffer to 0 for Size bytes. 96 97 @param Buffer The memory to set. 98 @param Length The number of bytes to set 99 100 @return Buffer. 101 102 **/ 103 VOID * 104 EFIAPI 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 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 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 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 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 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 } 261 262 /** 263 Checks whether the contents of a buffer are all zeros. 264 265 @param Buffer The pointer to the buffer to be checked. 266 @param Length The size of the buffer (in bytes) to be checked. 267 268 @retval TRUE Contents of the buffer are all zeros. 269 @retval FALSE Contents of the buffer are not all zeros. 270 271 **/ 272 BOOLEAN 273 EFIAPI 274 InternalMemIsZeroBuffer ( 275 IN CONST VOID *Buffer, 276 IN UINTN Length 277 ) 278 { 279 CONST UINT8 *BufferData; 280 UINTN Index; 281 282 BufferData = Buffer; 283 for (Index = 0; Index < Length; Index++) { 284 if (BufferData[Index] != 0) { 285 return FALSE; 286 } 287 } 288 return TRUE; 289 } 290
