bool PsxRelocator::parseObject(ByteArray data, PsxRelocatorFile& dest)
{
if (memcmp(data.data(),psxObjectFileMagicNum,sizeof(psxObjectFileMagicNum)) != 0)
return false;
int pos = 6;
std::vector<PsxSegment>& segments = dest.segments;
std::vector<PsxSymbol>& syms = dest.symbols;
int activeSegment = -1;
int lastSegmentPartStart = -1;
while (pos < data.size())
{
switch (data[pos])
{
case 0x10: // segment definition
{
PsxSegment seg;
seg.id = data.getDoubleWord(pos+1);
segments.push_back(seg);
pos += 5;
if (data[pos] != 8)
return false;
int nameLen = data[pos+1];
std::wstring& name = segments[segments.size()-1].name;
pos += 1 + loadString(data,pos+1,name);
}
break;
case 0x14: // group?
pos += data[pos+4]+5;
break;
case 0x1C: // source file name
pos += data[pos+3]+4;
break;
case 0x06: // set segment id
{
int id = data.getWord(pos+1);
pos += 3;
int num = -1;
for (size_t i = 0; i < segments.size(); i++)
{
if (segments[i].id == id)
{
num = i;
break;
}
}
activeSegment = num;
}
break;
case 0x02: // append to data segment
{
int size = data.getWord(pos+1);
pos += 3;
ByteArray d = data.mid(pos,size);
pos += size;
lastSegmentPartStart = segments[activeSegment].data.size();
segments[activeSegment].data.append(d);
}
break;
case 0x08: // append zeroes data segment
{
int size = data.getWord(pos+1);
pos += 3;
ByteArray d;
d.reserveBytes(size);
segments[activeSegment].data.append(d);
}
break;
case 0x0A: // relocation data
{
int type = data[pos+1];
pos += 2;
PsxRelocation rel;
rel.relativeOffset = 0;
rel.filePos = pos-2;
switch (type)
{
case 0x10: // 32 bit word
rel.type = PsxRelocationType::WordLiteral;
rel.segmentOffset = data.getWord(pos);
pos += 2;
break;
case 0x4A: // jal
rel.type = PsxRelocationType::FunctionCall;
rel.segmentOffset = data.getWord(pos);
pos += 2;
break;
case 0x52: // upper immerdiate
rel.type = PsxRelocationType::UpperImmediate;
rel.segmentOffset = data.getWord(pos);
pos += 2;
break;
case 0x54: // lower immediate (add)
rel.type = PsxRelocationType::LowerImmediate;
rel.segmentOffset = data.getWord(pos);
pos += 2;
break;
default:
return false;
}
rel.segmentOffset += lastSegmentPartStart;
checkothertype:
int otherType = data[pos++];
switch (otherType)
{
case 0x02: // reference to symbol with id num
rel.refType = PsxRelocationRefType::SymblId;
rel.referenceId = data.getWord(pos);
pos += 2;
break;
case 0x2C: // ref to other segment?
rel.refType = PsxRelocationRefType::SegmentOffset;
switch (data[pos++])
{
case 0x00:
rel.relativeOffset = data.getDoubleWord(pos);
pos += 4;
goto checkothertype;
case 0x04:
rel.referenceId = data.getWord(pos); // segment id
pos += 2;
if (data[pos++] != 0x00)
{
return false;
}
rel.referencePos = data.getDoubleWord(pos);
pos += 4;
break;
default:
return false;
}
break;
case 0x2E: // negative ref?
rel.refType = PsxRelocationRefType::SegmentOffset;
switch (data[pos++])
{
case 0x00:
rel.relativeOffset = -data.getDoubleWord(pos);
pos += 4;
goto checkothertype;
default:
return false;
}
break;
default:
return false;
}
segments[activeSegment].relocations.push_back(rel);
}
break;
case 0x12: // internal symbol
{
PsxSymbol sym;
sym.type = PsxSymbolType::Internal;
sym.segment = data.getWord(pos+1);
sym.offset = data.getDoubleWord(pos+3);
pos += 7 + loadString(data,pos+7,sym.name);
syms.push_back(sym);
}
break;
case 0x0E: // external symbol
{
PsxSymbol sym;
sym.type = PsxSymbolType::External;
sym.id = data.getWord(pos+1);
pos += 3 + loadString(data,pos+3,sym.name);
syms.push_back(sym);
}
break;
case 0x30: // bss symbol?
{
PsxSymbol sym;
sym.type = PsxSymbolType::BSS;
sym.id = data.getWord(pos+1);
sym.segment = data.getWord(pos+3);
sym.size = data.getDoubleWord(pos+5);
pos += 9 + loadString(data,pos+9,sym.name);
syms.push_back(sym);
}
break;
case 0x0C: // internal with id
{
PsxSymbol sym;
sym.type = PsxSymbolType::InternalID;
sym.id = data.getWord(pos+1);
sym.segment = data.getWord(pos+3);
sym.offset = data.getDoubleWord(pos+5);
pos += 9 + loadString(data,pos+9,sym.name);
syms.push_back(sym);
}
break;
case 0x4A: // function
{
PsxSymbol sym;
sym.type = PsxSymbolType::Function;
sym.segment = data.getWord(pos+1);
sym.offset = data.getDoubleWord(pos+3);
pos += 0x1D + loadString(data,pos+0x1D,sym.name);
syms.push_back(sym);
}
break;
case 0x4C: // function size
pos += 11;
break;
case 0x3C: // ??
pos += 3;
break;
case 0x00: // ??
pos++;
break;
case 0x32: // ??
pos += 3;
break;
case 0x3A: // ??
pos += 9;
break;
default:
return false;
}
}
return true;
}
