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◆ main openmsx / src / MSXS1985.cc
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#include "MSXS1985.hh"
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#include "MSXMapperIO.hh"
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#include "MSXMotherBoard.hh"
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#include "SRAM.hh"
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#include "serialize.hh"
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#include "enumerate.hh"
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#include "narrow.hh"
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#include <array>
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#include <memory>
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namespace openmsx {
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static constexpr uint8_t ID = 0xFE;
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MSXS1985::MSXS1985(const DeviceConfig& config)
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	: MSXDevice(config)
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	, MSXSwitchedDevice(getMotherBoard(), ID)
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{
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	if (!config.findChild("sramname")) {
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		// special case for backwards compatibility (S1985 didn't
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		// always have SRAM in its config...)
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		sram = std::make_unique<SRAM>(
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			getName() + " SRAM", "S1985 Backup RAM",
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			0x10, config, SRAM::DontLoadTag{});
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	} else {
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		sram = std::make_unique<SRAM>(
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			getName() + " SRAM", "S1985 Backup RAM",
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			0x10, config);
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	}
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	auto& mapperIO = getMotherBoard().createMapperIO();
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	uint8_t mask = 0b0001'1111; // always(?) 5 bits
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	auto baseValue = narrow_cast<uint8_t>(config.getChildDataAsInt("MapperReadBackBaseValue", 0x80));
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	mapperIO.setMode(MSXMapperIO::Mode::INTERNAL, mask, baseValue);
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	reset(EmuTime::dummy());
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}
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MSXS1985::~MSXS1985()
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{
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	getMotherBoard().destroyMapperIO();
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}
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void MSXS1985::reset(EmuTime /*time*/)
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{
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	color1 = color2 = pattern = address = 0; // TODO check this
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}
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uint8_t MSXS1985::readSwitchedIO(uint16_t port, EmuTime time)
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{
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	uint8_t result = peekSwitchedIO(port, time);
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	switch (port & 0x0F) {
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	case 7:
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		pattern = uint8_t((pattern << 1) | (pattern >> 7));
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		break;
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	}
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	return result;
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}
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uint8_t MSXS1985::peekSwitchedIO(uint16_t port, EmuTime /*time*/) const
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{
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	switch (port & 0x0F) {
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	case 0:
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		return uint8_t(~ID);
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	case 2:
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		return (*sram)[address];
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	case 7:
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		return (pattern & 0x80) ? color2 : color1;
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	default:
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		return 0xFF;
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	}
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}
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void MSXS1985::writeSwitchedIO(uint16_t port, uint8_t value, EmuTime /*time*/)
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{
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	switch (port & 0x0F) {
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	case 1:
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		address = value & 0x0F;
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		break;
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	case 2:
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		sram->write(address, value);
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		break;
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	case 6:
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		color2 = color1;
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		color1 = value;
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		break;
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	case 7:
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		pattern = value;
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		break;
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	}
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}
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// version 1: initial version
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// version 2: replaced RAM with SRAM
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template<typename Archive>
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void MSXS1985::serialize(Archive& ar, unsigned version)
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{
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	ar.template serializeBase<MSXDevice>(*this);
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	// no need to serialize MSXSwitchedDevice base class
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	if (ar.versionAtLeast(version, 2)) {
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		// serialize normally...
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		ar.serialize("sram", *sram);
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	} else {
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		assert(Archive::IS_LOADER);
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		// version 1 had here
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		//    <ram>
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		//      <ram encoding="..">...</ram>
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		//    </ram>
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		// deserialize that structure and transfer it to SRAM
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		std::array<uint8_t, 0x10> tmp;
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		ar.beginTag("ram");
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		ar.serialize_blob("ram", tmp);
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		ar.endTag("ram");
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		for (auto [i, t] : enumerate(tmp)) {
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			sram->write(unsigned(i), t);
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		}
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	}
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	ar.serialize("address", address,
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	             "color1",  color1,
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	             "color2",  color2,
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	             "pattern", pattern);
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}
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INSTANTIATE_SERIALIZE_METHODS(MSXS1985);
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REGISTER_MSXDEVICE(MSXS1985, "S1985");
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} // namespace openmsx