MSXMapperIO.hh

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#ifndef MSXMAPPERIO_HH
#define MSXMAPPERIO_HH
 
#include "MSXDevice.hh"
#include "MSXMotherBoard.hh"
#include "SimpleDebuggable.hh"
#include <vector>
 
namespace openmsx {
 
struct MSXMemoryMapperInterface
{
        [[nodiscard]] virtual byte readIO(word port, EmuTime::param time) = 0;
        [[nodiscard]] virtual byte peekIO(word port, EmuTime::param time) const = 0;
        virtual void writeIO(word port, byte value, EmuTime::param time) = 0;
        [[nodiscard]] virtual byte getSelectedSegment(byte page) const = 0;
protected:
        ~MSXMemoryMapperInterface() = default;
};
 
 
class MSXMapperIO final : public MSXDevice
{
public:
        enum class Mode { INTERNAL, EXTERNAL };
 
public:
        explicit MSXMapperIO(const DeviceConfig& config);
 
        void setMode(Mode mode, byte mask, byte baseValue);
 
        [[nodiscard]] byte readIO(word port, EmuTime::param time) override;
        [[nodiscard]] byte peekIO(word port, EmuTime::param time) const override;
        void writeIO(word port, byte value, EmuTime::param time) override;
 
        void registerMapper(MSXMemoryMapperInterface* mapper);
        void unregisterMapper(MSXMemoryMapperInterface* mapper);
 
        template<typename Archive>
        void serialize(Archive& ar, unsigned version);
 
private:
        struct Debuggable final : SimpleDebuggable {
                Debuggable(MSXMotherBoard& motherBoard, const std::string& name);
                [[nodiscard]] byte read(unsigned address) override;
                void write(unsigned address, byte value, EmuTime::param time) override;
        } debuggable;
 
        std::vector<MSXMemoryMapperInterface*> mappers;
 
        byte registers[4]; // (copy of) the mapper register state
        byte mask; // bitmask: 1-bit -> take mapper register, 0-bit -> take baseValue
        byte baseValue = 0xff;
        Mode mode = Mode::EXTERNAL; // use the internal or the external mapper state
};
SERIALIZE_CLASS_VERSION(MSXMapperIO, 3);
 
 
class MSXMapperIOClient : public MSXMemoryMapperInterface
{
protected:
        MSXMapperIOClient(MSXMotherBoard& motherBoard_)
                : motherBoard(motherBoard_)
        {
                auto& mapperIO = motherBoard.createMapperIO();
                mapperIO.registerMapper(this);
        }
 
        ~MSXMapperIOClient()
        {
                auto& mapperIO = motherBoard.getMapperIO();
                mapperIO.unregisterMapper(this);
                motherBoard.destroyMapperIO();
        }
 
private:
        MSXMotherBoard& motherBoard;
};
 
} // namespace openmsx
 
#endif