public PkLiteUnpacker(IServiceProvider services, string filename, byte [] rawImg) : base(services, filename, rawImg)
{
var exe = new ExeImageLoader(services, filename, rawImg);
arch = new IntelArchitecture(ProcessorMode.Real);
platform = new MsdosPlatform(services, arch);
uint pkLiteHdrOffset = (uint) (exe.e_cparHeader * 0x10);
if (RawImage[pkLiteHdrOffset] != 0xB8)
throw new ApplicationException(string.Format("Expected MOV AX,XXXX at offset 0x{0:X4}.", pkLiteHdrOffset));
uint cparUncompressed = LoadedImage.ReadLeUInt16(RawImage, pkLiteHdrOffset + 1);
abU = new byte[cparUncompressed * 0x10U];
if (RawImage[pkLiteHdrOffset + 0x04C] != 0x83)
throw new ApplicationException(string.Format("Expected ADD BX,+XX at offset 0x{0:X4}.", pkLiteHdrOffset + 0x04C));
uint offCompressedData = pkLiteHdrOffset + RawImage[pkLiteHdrOffset + 0x04E] * 0x10u - PspSize;
bitStm = new BitStream(RawImage, (int) offCompressedData);
}
public LoadedImage Unpack(byte [] abC, Address addrLoad)
{
// Extract the LZ stuff.
ImageReader rdr = new LeImageReader(abC, (uint) lzHdrOffset);
lzIp = rdr.ReadLeUInt16();
lzCs = rdr.ReadLeUInt16();
ushort lzSp = rdr.ReadLeUInt16();
ushort lzSs = rdr.ReadLeUInt16();
ushort lzcpCompressed = rdr.ReadLeUInt16();
ushort lzcpDecompressed = rdr.ReadLeUInt16();
// Find the start of the compressed stream.
int ifile = lzHdrOffset - (lzcpCompressed << 4);
// Allocate space for the decompressed goo.
int cbUncompressed = ((int) lzcpDecompressed + lzcpDecompressed) << 4;
byte [] abU = new byte[cbUncompressed];
// Decompress this sorry mess.
int len;
int span;
int p = 0;
BitStream bits = new BitStream(abC, ifile);
for (;;)
{
if (bits.GetBit() != 0)
{
// 1....
abU[p++] = bits.GetByte();
continue;
}
if (bits.GetBit() == 0)
{
// 00.....
len = bits.GetBit() << 1;
len |= bits.GetBit();
len += 2;
span = bits.GetByte() | ~0xFF;
}
else
{
// 01.....
span = bits.GetByte();
len = bits.GetByte();;
span |= ((len & ~0x07)<<5) | ~0x1FFF;
len = (len & 0x07) + 2;
if (len == 2)
{
len = bits.GetByte();
if (len == 0)
break; // end mark of compressed load module
if (len == 1)
continue; // segment change
else
++len;
}
}
for( ;len > 0; --len, ++p)
{
abU[p] = abU[p+span];
}
}
// Create a new image based on the uncompressed data.
this.imgLoaded = new LoadedImage(addrLoad, abU);
this.imageMap = imgLoaded.CreateImageMap();
return imgLoaded;
}
public uint CopyDictionaryWord2(byte [] abU, int BX, int bytes, BitStream stm, uint dst)
{
BX = (ushort) (ab022C[BX] << 8);
return CopyDictionaryWord(abU, BX, bytes, stm, dst);
}
public uint CopyDictionaryWord(byte [] abU, int offset, int bytes, BitStream stm, uint dst)
{
offset |= stm.GetByte();
var src = dst - offset;
do
{
abU[dst++] = abU[src++];
} while (--bytes != 0);
return dst;
}