71 lines
1.7 KiB
C
71 lines
1.7 KiB
C
/** @file
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UEFI Decompress Library implementation refer to UEFI specification.
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Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
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Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include <Base.h>
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#include <Library/BaseLib.h>
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#include <Library/DebugLib.h>
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#include <Library/BaseMemoryLib.h>
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/**
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Decompress data blob using RLE.
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@param Data Source data buffer pointer.
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@param Length Source data size.
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@param Buffer Destination data buffer.
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If NULL, no data will be written.
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The caller needs to ensure the buffer size is big enough.
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@retval Decompressed data length.
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**/
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UINTN
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RleDecompressData (
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IN UINT8 *Data,
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IN UINTN Length,
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IN OUT UINT8 *Buffer
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)
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{
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UINTN Index;
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UINT16 LastChar;
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UINTN LastCharCount;
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UINT8 CurrentChar;
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UINT8 Repeat;
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UINTN DeCompressedIndex;
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LastChar = (UINT16) -1;
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LastCharCount = 0;
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DeCompressedIndex = 0;
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for (Index = 0; Index < Length; Index++) {
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CurrentChar = Data[Index];
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if (LastCharCount == 2) {
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LastCharCount = 0;
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Repeat = CurrentChar;
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if (Buffer != NULL) {
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SetMem (Buffer, Repeat, (UINT8)LastChar);
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Buffer += Repeat;
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}
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DeCompressedIndex += Repeat;
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LastChar = (UINT16) -1;
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} else {
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if (LastChar != CurrentChar) {
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LastCharCount = 0;
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}
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LastCharCount++;
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if (Buffer != NULL) {
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*Buffer++ = CurrentChar;
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}
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LastChar = CurrentChar;
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DeCompressedIndex++;
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}
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}
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return DeCompressedIndex;
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}
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