RomMSXDOS2.cc

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#include "RomMSXDOS2.hh"
#include "Rom.hh"
#include "CacheLine.hh"
#include "MSXException.hh"
#include "serialize.hh"
#include "unreachable.hh"

namespace openmsx {

RomMSXDOS2::RomMSXDOS2(const DeviceConfig& config, std::unique_ptr<Rom> rom_)
        : Rom16kBBlocks(config, std::move(rom_))
        , range((*rom)[0x94])
{
        if ((range != 0x00) && (range != 0x60) && (range != 0x7f)) {
                throw MSXException("Invalid rom for MSXDOS2 mapper");
        }
        reset(EmuTime::dummy());
}

void RomMSXDOS2::reset(EmuTime::param /*time*/)
{
        setUnmapped(0);
        setRom(1, 0);
        setUnmapped(2);
        setUnmapped(3);
}

void RomMSXDOS2::writeMem(word address, byte value, EmuTime::param /*time*/)
{
        switch (range) {
        case 0x00:
                if (address != 0x7ff0) return;
                break;
        case 0x60:
                if ((address & 0xf000) != 0x6000) return;
                break;
        case 0x7f:
                if (address != 0x7ffe) return;
                break;
        default:
                UNREACHABLE;
        }
        setRom(1, value);
}

byte* RomMSXDOS2::getWriteCacheLine(word address) const
{
        switch (range) {
        case 0x00:
                if (address == (0x7ff0 & CacheLine::HIGH)) return nullptr;
                break;
        case 0x60:
                if ((address & 0xf000) == 0x6000) return nullptr;
                break;
        case 0x7f:
                if (address == (0x7ffe & CacheLine::HIGH)) return nullptr;
                break;
        default:
                UNREACHABLE;
        }
        return unmappedWrite;
}

REGISTER_MSXDEVICE(RomMSXDOS2, "RomMSXDOS2");

} // namespace openmsx