CloverBootloader/Library/OcMiscLib/DataPatcher.c
2020-07-09 22:06:48 +03:00

118 lines
2.7 KiB
C

/** @file
Copyright (C) 2019, vit9696. All rights reserved.
All rights reserved.
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/OcMiscLib.h>
INT32
FindPattern (
IN CONST UINT8 *Pattern,
IN CONST UINT8 *PatternMask OPTIONAL,
IN CONST UINT32 PatternSize,
IN CONST UINT8 *Data,
IN UINT32 DataSize,
IN INT32 DataOff
)
{
BOOLEAN Matches;
UINT32 Index;
ASSERT (DataOff >= 0);
if (PatternSize == 0 || DataSize == 0 || (DataOff < 0) || (UINT32)DataOff >= DataSize || DataSize - DataOff < PatternSize) {
return -1;
}
while (DataOff + PatternSize < DataSize) {
Matches = TRUE;
for (Index = 0; Index < PatternSize; ++Index) {
if ((PatternMask == NULL && Data[DataOff + Index] != Pattern[Index])
|| (PatternMask != NULL && (Data[DataOff + Index] & PatternMask[Index]) != Pattern[Index])) {
Matches = FALSE;
break;
}
}
if (Matches) {
return DataOff;
}
++DataOff;
}
return -1;
}
UINT32
ApplyPatch (
IN CONST UINT8 *Pattern,
IN CONST UINT8 *PatternMask OPTIONAL,
IN CONST UINT32 PatternSize,
IN CONST UINT8 *Replace,
IN CONST UINT8 *ReplaceMask OPTIONAL,
IN UINT8 *Data,
IN UINT32 DataSize,
IN UINT32 Count,
IN UINT32 Skip
)
{
UINT32 ReplaceCount;
INT32 DataOff;
ReplaceCount = 0;
DataOff = 0;
do {
DataOff = FindPattern (Pattern, PatternMask, PatternSize, Data, DataSize, DataOff);
if (DataOff >= 0) {
//
// Skip this finding if requested.
//
if (Skip > 0) {
--Skip;
DataOff += PatternSize;
continue;
}
//
// Perform replacement.
//
if (ReplaceMask == NULL) {
CopyMem (&Data[DataOff], Replace, PatternSize);
} else {
for (UINTN Index = 0; Index < PatternSize; ++Index) {
Data[DataOff + Index] = (Data[DataOff + Index] & ~ReplaceMask[Index]) | (Replace[Index] & ReplaceMask[Index]);
}
}
++ReplaceCount;
DataOff += PatternSize;
//
// Check replace count if requested.
//
if (Count > 0) {
--Count;
if (Count == 0) {
break;
}
}
}
} while (DataOff >= 0);
return ReplaceCount;
}