Mesen-SX/Core/BaseCartridge.cpp

#include "stdafx.h"
#include "BaseCartridge.h"
#include "RamHandler.h"
#include "RomHandler.h"
#include "MemoryManager.h"
#include "IMemoryHandler.h"
#include "MessageManager.h"
#include "../Utilities/HexUtilities.h"
#include "../Utilities/VirtualFile.h"
#include "../Utilities/FolderUtilities.h"
#include "../Utilities/Serializer.h"
#include "../Utilities/sha1.h"

BaseCartridge::~BaseCartridge()
{
	SaveBattery();

	delete[] _prgRom;
	delete[] _saveRam;
}

shared_ptr<BaseCartridge> BaseCartridge::CreateCartridge(VirtualFile &romFile, VirtualFile &patchFile)
{
	if(romFile.IsValid()) {
		shared_ptr<BaseCartridge> cart(new BaseCartridge());
		if(patchFile.IsValid()) {
			cart->_patchPath = patchFile;
			if(romFile.ApplyPatch(patchFile)) {
				MessageManager::DisplayMessage("Patch", "ApplyingPatch", patchFile.GetFileName());
			}
		}

		vector<uint8_t> romData;
		romFile.ReadFile(romData);
		
		if(romData.size() < 0x8000) {
			return nullptr;
		}

		cart->_romPath = romFile;
		cart->_prgRomSize = (uint32_t)romData.size();
		cart->_prgRom = new uint8_t[cart->_prgRomSize];
		memcpy(cart->_prgRom, romData.data(), cart->_prgRomSize);
		cart->Init();

		return cart;
	} else {
		return nullptr;
	}
}

int32_t BaseCartridge::GetHeaderScore(uint32_t addr)
{
	//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;
	}

	uint32_t resetVectorAddr = addr + 0x7FFC;
	uint32_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()
{
	//Find the best potential header among lorom/hirom + headerless/headered combinations
	vector<uint32_t> baseAddresses = { 0, 0x200, 0x8000, 0x8200, 0x408000, 0x408200 };
	int32_t bestScore = -1;
	bool hasHeader = false;
	bool isLoRom = true;
	bool isExRom = true;
	for(uint32_t baseAddress : baseAddresses) {
		int32_t score = GetHeaderScore(baseAddress);
		if(score >= 0 && score >= bestScore) {
			bestScore = score;
			isLoRom = (baseAddress & 0x8000) == 0;
			isExRom = (baseAddress & 0x400000) != 0;
			hasHeader = (baseAddress & 0x200) != 0;
			uint32_t headerOffset = std::min(baseAddress + 0x7FB0, _prgRomSize - 0x40);
			memcpy(&_cartInfo, _prgRom + headerOffset, sizeof(SnesCartInformation));
		}
	}

	uint32_t flags = 0;
	if(isLoRom) {
		if(hasHeader) {
			flags |= CartFlags::CopierHeader;
		}
		flags |= CartFlags::LoRom;
	} else {
		if(hasHeader) {
			flags |= CartFlags::CopierHeader;
		}
		flags |= isExRom ? CartFlags::ExHiRom : CartFlags::HiRom;
	}

	if(flags & CartFlags::CopierHeader) {
		//Remove the copier header
		memmove(_prgRom, _prgRom + 512, _prgRomSize - 512);
		_prgRomSize -= 512;
	}
	
	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];

	LoadBattery();

	DisplayCartInfo();
}

RomInfo BaseCartridge::GetRomInfo()
{
	RomInfo info;
	info.Header = _cartInfo;
	info.RomFile = static_cast<VirtualFile>(_romPath);
	info.PatchFile = static_cast<VirtualFile>(_patchPath);
	return info;
}

string BaseCartridge::GetSha1Hash()
{
	return SHA1::GetHash(_prgRom, _prgRomSize);
}

void BaseCartridge::LoadBattery()
{
	if(_saveRamSize > 0) {
		string saveFilePath = FolderUtilities::CombinePath(FolderUtilities::GetSaveFolder(), FolderUtilities::GetFilename(_romPath, false) + ".srm");
		VirtualFile saveFile(saveFilePath);
		if(saveFile.IsValid()) {
			vector<uint8_t> saveData;
			saveFile.ReadFile(saveData);

			if(saveData.size() == _saveRamSize) {
				memcpy(_saveRam, saveData.data(), _saveRamSize);
			}
		}
	}
}

void BaseCartridge::SaveBattery()
{
	if(_saveRamSize > 0) {
		string saveFilePath = FolderUtilities::CombinePath(FolderUtilities::GetSaveFolder(), FolderUtilities::GetFilename(_romPath, false) + ".srm");
		ofstream saveFile(saveFilePath, ios::binary);
		saveFile.write((char*)_saveRam, _saveRamSize);
	}
}

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, uint16_t startPageNumber)
{
	if(handlers.empty()) {
		return;
	}

	while(startPageNumber >= handlers.size()) {
		startPageNumber -= (uint32_t)handlers.size();
	}

	uint32_t pageNumber = startPageNumber;
	for(uint32_t i = startBank; i <= endBank; i++) {
		uint32_t baseAddress = i << 16;
		pageNumber += pageIncrement;
		for(uint32_t j = startPage; j <= endPage; j++) {
			mm.RegisterHandler(baseAddress + (j * 0x1000), (baseAddress + (j * 0x1000)) | 0xFFF, handlers[pageNumber].get());
			//MessageManager::Log("Map [$" + HexUtilities::ToHex(i) + ":" + HexUtilities::ToHex(j)[1] + "xxx] to page number " + HexUtilities::ToHex(pageNumber));
			pageNumber++;
			if(pageNumber >= handlers.size()) {
				if(mirror) {
					pageNumber = 0;
				} else {
					return;
				}
			}
		}
	}
}

void BaseCartridge::RegisterHandlers(MemoryManager &mm)
{
	for(uint32_t i = 0; i < _prgRomSize; i += 0x1000) {
		_prgRomHandlers.push_back(unique_ptr<RomHandler>(new RomHandler(_prgRom, i, _prgRomSize, SnesMemoryType::PrgRom)));
	}

	uint32_t power = (uint32_t)std::log2(_prgRomSize);
	if(_prgRomSize > (1u << power)) {
		//If size isn't a power of 2, mirror the part above the nearest (lower) power of 2 until the size reaches the next power of 2.
		uint32_t halfSize = 1 << power;
		uint32_t fullSize = 1 << (power + 1);
		uint32_t extraHandlers = std::max<uint32_t>((_prgRomSize - halfSize) / 0x1000, 1);

		while(_prgRomHandlers.size() < fullSize / 0x1000) {
			for(uint32_t i = 0; i < extraHandlers; i += 0x1000) {
				_prgRomHandlers.push_back(unique_ptr<RomHandler>(new RomHandler(_prgRom, halfSize + i, _prgRomSize, SnesMemoryType::PrgRom)));
			}
		}
	}

	for(uint32_t i = 0; i < _saveRamSize; i += 0x1000) {
		_saveRamHandlers.push_back(unique_ptr<RamHandler>(new RamHandler(_saveRam, i, _saveRamSize, SnesMemoryType::SaveRam)));
	}

	if(MapSpecificCarts(mm)) {
		return;
	}

	if(_flags & CartFlags::LoRom) {
		MapBanks(mm, _prgRomHandlers, 0x00, 0x7D, 0x08, 0x0F, 0, true);
		MapBanks(mm, _prgRomHandlers, 0x80, 0xFF, 0x08, 0x0F, 0, true);

		if(_saveRamSize > 0) {
			if(_prgRomSize >= 1024 * 1024 * 2) {
				//For games >= 2mb in size, put ROM at 70-7D/F0-FF:0000-7FFF (e.g: Fire Emblem: Thracia 776) 
				MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x00, 0x07, 0, true);
				MapBanks(mm, _saveRamHandlers, 0xF0, 0xFF, 0x00, 0x07, 0, true);
			} else {
				//For games < 2mb in size, put save RAM at 70-7D/F0-FF:0000-FFFF (e.g: Wanderers from Ys) 
				MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x00, 0x0F, 0, true);
				MapBanks(mm, _saveRamHandlers, 0xF0, 0xFF, 0x00, 0x0F, 0, true);
			}
		}
	} else if(_flags & CartFlags::HiRom) {
		MapBanks(mm, _prgRomHandlers, 0x00, 0x3F, 0x08, 0x0F, 8, true);
		MapBanks(mm, _prgRomHandlers, 0x40, 0x7D, 0x00, 0x0F, 0, true);
		MapBanks(mm, _prgRomHandlers, 0x80, 0xBF, 0x08, 0x0F, 8, true);
		MapBanks(mm, _prgRomHandlers, 0xC0, 0xFF, 0x00, 0x0F, 0, true);

		MapBanks(mm, _saveRamHandlers, 0x20, 0x3F, 0x06, 0x07, 0, true);
		MapBanks(mm, _saveRamHandlers, 0xA0, 0xBF, 0x06, 0x07, 0, true);
	} else if(_flags & CartFlags::ExHiRom) {
		//First half is at the end
		MapBanks(mm, _prgRomHandlers, 0xC0, 0xFF, 0x00, 0x0F, 0, true);
		MapBanks(mm, _prgRomHandlers, 0x80, 0xBF, 0x08, 0x0F, 8, true); //mirror

		//Last part of the ROM is at the start
		MapBanks(mm, _prgRomHandlers, 0x40, 0x7D, 0x00, 0x0F, 0, true, 0x400);
		MapBanks(mm, _prgRomHandlers, 0x00, 0x3F, 0x08, 0x0F, 8, true, 0x400); //mirror

		//Save RAM
		MapBanks(mm, _saveRamHandlers, 0x20, 0x3F, 0x06, 0x07, 0, true);
		MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x00, 0x07, 0, true);
		MapBanks(mm, _saveRamHandlers, 0xA0, 0xBF, 0x06, 0x07, 0, true);
	}
}

bool BaseCartridge::MapSpecificCarts(MemoryManager &mm)
{
	string name = GetCartName();
	string code = GetGameCode();
	if(GetCartName() == "DEZAEMON") {
		//LOROM with mirrored SRAM?
		MapBanks(mm, _prgRomHandlers, 0x00, 0x7D, 0x08, 0x0F, 0, true);
		MapBanks(mm, _prgRomHandlers, 0x80, 0xFF, 0x08, 0x0F, 0, true);

		MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x00, 0x07, 0, true);
		MapBanks(mm, _saveRamHandlers, 0xF0, 0xFF, 0x08, 0x0F, 0, true);

		//Mirrors
		MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x08, 0x0F, 0, true);
		MapBanks(mm, _saveRamHandlers, 0xF0, 0xFF, 0x00, 0x07, 0, true);

		return true;
	} else if(code == "ZDBJ" || code == "ZR2J" || code == "ZSNJ") {
		//BSC-1A5M-02, BSC-1A7M-01
		//Games: Sound Novel Tsukuuru, RPG Tsukuuru, Derby Stallion 96
		MapBanks(mm, _prgRomHandlers, 0x00, 0x3F, 0x08, 0x0F, 0, true);
		MapBanks(mm, _prgRomHandlers, 0x80, 0x9F, 0x08, 0x0F, 0, true, 0x200);
		MapBanks(mm, _prgRomHandlers, 0xA0, 0xBF, 0x08, 0x0F, 0, true, 0x100);
		if(_saveRamSize > 0) {
			MapBanks(mm, _saveRamHandlers, 0x70, 0x7D, 0x00, 0x07, 0, true);
			MapBanks(mm, _saveRamHandlers, 0xF0, 0xFF, 0x00, 0x07, 0, true);
		}
		return true;
	}
	return false;
}

void BaseCartridge::Serialize(Serializer &s)
{
	s.StreamArray(_saveRam, _saveRamSize);
}

string BaseCartridge::GetGameCode()
{
	string code;
	code += _cartInfo.GameCode[0];
	code += _cartInfo.GameCode[1];
	code += _cartInfo.GameCode[2];
	code += _cartInfo.GameCode[3];
	return code;
}

string BaseCartridge::GetCartName()
{
	int nameLength = 21;
	for(int i = 0; i < 21; i++) {
		if(_cartInfo.CartName[i] == 0) {
			nameLength = i;
			break;
		}
	}
	string name = string(_cartInfo.CartName, nameLength);

	size_t lastNonSpace = name.find_last_not_of(' ');
	if(lastNonSpace != string::npos) {
		return name.substr(0, lastNonSpace + 1);
	} else {
		return name;
	}
}

void BaseCartridge::DisplayCartInfo()
{
	MessageManager::Log("-----------------------------");
	MessageManager::Log("Game: " + GetCartName());
	if(_flags & CartFlags::ExHiRom) {
		MessageManager::Log("Type: ExHiROM");
	} 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) {
		MessageManager::Log("FastROM");
	}

	if(_flags & CartFlags::CopierHeader) {
		MessageManager::Log("Copier header found.");
	}

	MessageManager::Log("Map Mode: $" + HexUtilities::ToHex(_cartInfo.MapMode));
	MessageManager::Log("Rom Type: $" + HexUtilities::ToHex(_cartInfo.RomType));

	MessageManager::Log("File size: " + std::to_string(_prgRomSize / 1024) + " KB");
	MessageManager::Log("ROM size: " + std::to_string((0x400 << _cartInfo.RomSize) / 1024) + " KB");
	if(_saveRamSize > 0) {
		MessageManager::Log("SRAM size: " + std::to_string(_saveRamSize / 1024) + " KB");
	}
	MessageManager::Log("-----------------------------");
}