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Cart: Improved logic used to find header and select between cart types

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This commit is contained in:
Sour 2019-03-08 20:18:13 -05:00
parent ae2cec058a
commit 9a0624b948
2 changed files with 88 additions and 47 deletions
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132
Core/BaseCartridge.cpp
View file

@ -36,28 +36,89 @@ shared_ptr<BaseCartridge> BaseCartridge::CreateCartridge(VirtualFile &romFile, V
}
}
void BaseCartridge::Init()
int32_t BaseCartridge::GetHeaderScore(uint32_t addr)
{
uint32_t headerOffset = 0;
if(((0x400 << _prgRom[0x7FD7]) == _prgRomSize && (_prgRom[0x7FD5] & 0x20)) || _prgRomSize < 0xFFFF) {
//LoROM
headerOffset = 0x7FB0;
} else if((0x400 << _prgRom[0xFFD7]) == _prgRomSize && (_prgRom[0xFFD5] & 0x20)) {
//HiROM
headerOffset = 0xFFB0;
} else if(_prgRom[0x7FD5] & 0x20) {
//LoROM
headerOffset = 0x7FB0;
} else if(_prgRom[0xFFD5] & 0x20) {
//HiROM
headerOffset = 0xFFB0;
} else {
headerOffset = 0x7FB0;
//throw std::runtime_error("invalid rom (?)");
//Try to figure out where the header is by using a scoring system
if(_prgRomSize < addr + 0x7FFF) {
return -1;
}
SnesCartInformation cartInfo;
memcpy(&cartInfo, _prgRom + addr + 0x7FB0, sizeof(SnesCartInformation));
uint32_t score = 0;
uint8_t mode = (cartInfo.MapMode & ~0x10);
if((mode == 0x20 || mode == 0x22) && addr < 0x8000) {
score++;
} else if((mode == 0x21 || mode == 0x25) && addr >= 0x8000) {
score++;
}
if(cartInfo.RomType < 0x08) {
score++;
}
if(cartInfo.RomSize < 0x10) {
score++;
}
if(cartInfo.SramSize < 0x08) {
score++;
}
uint16_t checksum = cartInfo.Checksum[0] | (cartInfo.Checksum[1] << 8);
uint16_t complement = cartInfo.ChecksumComplement[0] | (cartInfo.ChecksumComplement[1] << 8);
if(checksum + complement == 0xFFFF && checksum != 0 && complement != 0) {
score += 8;
}
uint16_t resetVectorAddr = addr + 0x7FFC;
uint16_t resetVector = _prgRom[resetVectorAddr] | (_prgRom[resetVectorAddr + 1] << 8);
if(resetVector < 0x8000) {
return -1;
}
uint8_t op = _prgRom[addr | (resetVector & 0x7FFF)];
if(op == 0x18 || op == 0x78 || op == 0x4C || op == 0x5C || op == 0x20 || op == 0x22 || op == 0x9C) {
//CLI, SEI, JMP, JML, JSR, JSl, STZ
score += 8;
} else if(op == 0xC2 || op == 0xE2 || op == 0xA9 || op == 0xA2 || op == 0xA0) {
//REP, SEP, LDA, LDX, LDY
score += 4;
} else if(op == 0x00 || op == 0xFF || op == 0xCC) {
//BRK, SBC, CPY
score -= 8;
}
return std::max<int32_t>(0, score);
}
void BaseCartridge::Init()
{
int32_t loRomScore = GetHeaderScore(0x0000);
int32_t hiRomScore = GetHeaderScore(0x8000);
uint32_t headerOffset = 0;
uint32_t flags = 0;
if(loRomScore >= hiRomScore) {
flags |= CartFlags::LoRom;
headerOffset = 0x7FB0;
} else {
flags |= CartFlags::HiRom;
headerOffset = 0xFFB0;
}
memcpy(&_cartInfo, _prgRom + headerOffset, sizeof(SnesCartInformation));
if((flags & CartFlags::HiRom) && (_cartInfo.MapMode & 0x27) == 0x25) {
flags |= CartFlags::ExHiRom;
} else if((flags & CartFlags::LoRom) && (_cartInfo.MapMode & 0x27) == 0x22) {
flags |= CartFlags::ExLoRom;
}
if(_cartInfo.MapMode & 0x10) {
flags |= CartFlags::FastRom;
}
_flags = (CartFlags::CartFlags)flags;
_saveRamSize = _cartInfo.SramSize > 0 ? 1024 * (1 << _cartInfo.SramSize) : 0;
_saveRam = new uint8_t[_saveRamSize];
@ -99,26 +160,6 @@ void BaseCartridge::SaveBattery()
}
}
CartFlags::CartFlags BaseCartridge::GetCartFlags()
{
uint32_t flags = 0;
if(_cartInfo.MapMode & 0x04) {
flags |= CartFlags::ExHiRom;
} else if(_cartInfo.MapMode & 0x02) {
flags |= CartFlags::ExLoRom;
} else if(_cartInfo.MapMode & 0x01) {
flags |= CartFlags::HiRom;
} else {
flags |= CartFlags::LoRom;
}
if(_cartInfo.MapMode & 0x10) {
flags |= CartFlags::FastRom;
}
return (CartFlags::CartFlags)flags;
}
void BaseCartridge::MapBanks(MemoryManager &mm, vector<unique_ptr<IMemoryHandler>> &handlers, uint8_t startBank, uint8_t endBank, uint16_t startPage, uint16_t endPage, uint16_t pageIncrement, bool mirror)
{
if(handlers.empty()) {
@ -154,7 +195,7 @@ void BaseCartridge::RegisterHandlers(MemoryManager &mm)
_saveRamHandlers.push_back(unique_ptr<RamHandler>(new RamHandler(_saveRam, i, _saveRamSize, SnesMemoryType::SaveRam)));
}
if(GetCartFlags() & CartFlags::LoRom) {
if(_flags & CartFlags::LoRom) {
if(_saveRamSize > 0) {
MapBanks(mm, _prgRomHandlers, 0x00, 0x6F, 0x08, 0x0F, 0, true);
MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x00, 0x0F, 0, true);
@ -186,20 +227,19 @@ void BaseCartridge::DisplayCartInfo()
}
}
CartFlags::CartFlags flags = GetCartFlags();
MessageManager::Log("-----------------------------");
MessageManager::Log("Game: " + string(_cartInfo.CartName, nameLength));
if(flags & CartFlags::HiRom) {
MessageManager::Log("Type: HiROM");
} else if(flags & CartFlags::LoRom) {
MessageManager::Log("Type: LoROM");
} else if(flags & CartFlags::ExHiRom) {
if(_flags & CartFlags::ExHiRom) {
MessageManager::Log("Type: ExHiROM");
} else if(flags & CartFlags::ExLoRom) {
} else if(_flags & CartFlags::ExLoRom) {
MessageManager::Log("Type: ExLoROM");
} else if(_flags & CartFlags::HiRom) {
MessageManager::Log("Type: HiROM");
} else if(_flags & CartFlags::LoRom) {
MessageManager::Log("Type: LoROM");
}
if(flags & CartFlags::FastRom) {
if(_flags & CartFlags::FastRom) {
MessageManager::Log("FastROM");
}

3
Core/BaseCartridge.h
View file

@ -53,6 +53,7 @@ private:
vector<unique_ptr<IMemoryHandler>> _saveRamHandlers;
SnesCartInformation _cartInfo;
CartFlags::CartFlags _flags;
string _romPath;
uint8_t* _prgRom = nullptr;
@ -66,7 +67,7 @@ private:
void LoadBattery();
void SaveBattery();
CartFlags::CartFlags GetCartFlags();
int32_t GetHeaderScore(uint32_t addr);
void DisplayCartInfo();
public: