public void LoadElfIdentification()
{
var rdr = new BeImageReader(base.RawImage, 0);
var elfMagic = rdr.ReadBeInt32();
if (elfMagic != ELF_MAGIC)
{
throw new BadImageFormatException("File is not in ELF format.");
}
this.fileClass = rdr.ReadByte();
this.endianness = rdr.ReadByte();
this.fileVersion = rdr.ReadByte();
this.osAbi = rdr.ReadByte();
}
private int GetRunLengthValue(BeImageReader a5dr, ref int a5repeat)
{
// Run length returned is in byte(s).
// next byte read - see bit pattern from the following table for the return value
// 0xxxxxxx - 0 - $7F
// 10xxxxxx - 0 - $3FFF(run length and $3F + next byte, 14 bits)
// 110xxxxx - 0 - $1FFFFF(run length and $1F + next two bytes, 21 bits)
// 1110xxxx - next 4 bytes, 32 bits
// 1111xxxx - get both new runtime length copy in bytes and new runtime length repeat count
int runLength = a5dr.ReadByte();
if ((runLength & 0x80) == 0)
{
return(runLength);
}
if ((runLength & 0x40) == 0)
{
runLength = runLength & 0x3F;
runLength = (runLength << 8) + a5dr.ReadByte();
return(runLength);
}
if ((runLength & 0x20) == 0)
{
runLength = runLength & 0x1F;
runLength = (runLength << 16) + a5dr.ReadBeInt16();
return(runLength);
}
if ((runLength & 0x10) == 0)
{
return(a5dr.ReadBeInt32());
}
runLength = GetRunLengthValue(a5dr, ref a5repeat);
a5repeat = GetRunLengthValue(a5dr, ref a5repeat);
return(runLength);
}
private void A5Expand(BeImageReader a5dr, UInt32 a5dbelow)
{
var a5belowWriter = new BeImageWriter(platform.A5World.MemoryArea, platform.A5Offset - a5dbelow);
int a5RunLengthToken = 0;
int a5RunLengthCopySize = 0;
int a5globalSkip = 0;
int a5repeat = 0;
var a5copylength = 0;
bool a5dataEnd = false;
// Compressed data
// set Repeat count = 1, reset after each completed copy cycle
// byte token lower 4 bits number of words to copy from compressed data
// byte token upper 4 bits number of words to skip in global application data space
// if either value is 0 then get run length value which is in bytes.
// if the new run length value for copy is 0 then it's the end of compression data.
do
{
a5repeat = 1;
// Token value - upper nibble is words to skip, lower nibble is words to copy
a5RunLengthToken = a5dr.ReadByte();
a5globalSkip = a5RunLengthToken;
a5RunLengthCopySize = a5RunLengthToken & 0x0F;
if (a5RunLengthCopySize == 0)
{
a5RunLengthCopySize = GetRunLengthValue(a5dr, ref a5repeat);
if (a5RunLengthCopySize == 0)
{
a5dataEnd = true;
}
}
else
{
a5RunLengthCopySize = a5RunLengthCopySize * 2;
}
if (!a5dataEnd)
{
a5globalSkip = a5globalSkip & 0xF0;
if (a5globalSkip == 0)
{
a5globalSkip = GetRunLengthValue(a5dr, ref a5repeat);
}
else
{
// convert value 0x01 - 0x0F number of words to skip in upper nibble to number of bytes to skip
a5globalSkip = a5globalSkip >> 3;
}
do
{
a5belowWriter.Position = a5belowWriter.Position + a5globalSkip;
a5copylength = a5RunLengthCopySize;
do
{
a5belowWriter.WriteByte(a5dr.ReadByte());
a5copylength -= 1;
} while (a5copylength > 0);
a5repeat -= 1;
} while (a5repeat > 0);
}
} while (!a5dataEnd);
}
public void Relocate()
{
var memA5 = (ByteMemoryArea)platform.A5World.MemoryArea;
var a5belowWriter = new BeImageWriter(memA5, 0);
var a5belowReader = new BeImageReader(memA5, 0);
uint a5globalOffset = platform.A5Offset - a5dbelow;
var a5WorldAddress = (UInt32)((platform.A5World.Address.Offset + platform.A5Offset) & 0xFFFFFFFF);
// set Repeat count = 1, reset after each completed copy cycle
// byte token lower 4 bits number of words to copy from compressed data
// byte token upper 4 bits number of words to skip in global application data space
// if either value is 0 then get run length value which is in bytes.
// if the new run length value for copy is 0 then it's the end of compression data.
for (;;)
{
int a5repeat = 1;
// Skip is number of 16-bit words to skip
uint a5globalSkip = a5dr.ReadByte();
if (a5globalSkip == 0)
{
a5globalSkip = a5dr.ReadByte();
if (a5globalSkip == 0)
{
break;
}
if (a5globalSkip > 0x7F)
{
a5globalSkip = ((a5globalSkip & 0x7F) << 8) + a5dr.ReadByte();
a5globalSkip = (a5globalSkip << 16) + a5dr.ReadBeUInt16();
}
else
{
a5repeat = ResourceFork.GetRunLengthValue(a5dr, ref a5repeat);
//$BUG: a5repeat could return the value 0. The do-while below will
// decrement a5repeat before testing. This will lead to an effective
// repeat count of 2^32; likely not wanted.
}
}
else
{
if ((a5globalSkip & 0x80) == 0x80)
{
a5globalSkip = ((a5globalSkip & 0x7F) << 8) + a5dr.ReadByte();
}
}
a5globalSkip = a5globalSkip * 2;
do
{
a5globalOffset += a5globalSkip;
a5belowReader.Seek(a5globalOffset, SeekOrigin.Begin);
uint a5ptrOffset = a5belowReader.ReadBeUInt32();
a5belowWriter.Position = (int)a5globalOffset;
// write relocated A5World pointers to absolute address in A5World segment
// Possible register/mark as Global pointer references to strings
a5belowWriter.WriteBeUInt32((a5WorldAddress + a5ptrOffset) & 0xFFFFFFFF);
--a5repeat;
} while (a5repeat > 0);
}
}
