PanasonicMemory.cc

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#include "PanasonicMemory.hh"
#include "MSXMotherBoard.hh"
#include "MSXCPU.hh"
#include "Ram.hh"
#include "Rom.hh"
#include "DeviceConfig.hh"
#include "HardwareConfig.hh"
#include "XMLElement.hh"
#include "MSXException.hh"
#include "memory.hh"

namespace openmsx {

static std::unique_ptr<Rom> createRom(MSXMotherBoard& motherBoard)
{
        const XMLElement* elem = motherBoard.getMachineConfig()->
                              getConfig().findChild("PanasonicRom");
        if (!elem) return nullptr;

        const HardwareConfig* hwConf = motherBoard.getMachineConfig();
        assert(hwConf);
        return make_unique<Rom>(
                "PanasonicRom", "Turbor-R main ROM",
                DeviceConfig(*hwConf, *elem));
}

PanasonicMemory::PanasonicMemory(MSXMotherBoard& motherBoard)
        : msxcpu(motherBoard.getCPU())
        , rom(createRom(motherBoard))
        , ram(nullptr), ramSize(0)
        , dram(false)
{
}

PanasonicMemory::~PanasonicMemory() = default;

void PanasonicMemory::registerRam(Ram& ram_)
{
        ram = &ram_[0];
        ramSize = ram_.getSize();
}

const byte* PanasonicMemory::getRomBlock(unsigned block)
{
        if (!rom) {
                throw MSXException("Missing PanasonicRom.");
        }
        if (dram &&
            (((0x28 <= block) && (block < 0x2C)) ||
             ((0x38 <= block) && (block < 0x3C)))) {
                assert(ram);
                unsigned offset = (block & 0x03) * 0x2000;
                unsigned ramOffset = (block < 0x30) ? ramSize - 0x10000 :
                                                      ramSize - 0x08000;
                return ram + ramOffset + offset;
        } else {
                unsigned offset = block * 0x2000;
                if (offset >= rom->getSize()) {
                        offset &= rom->getSize() - 1;
                }
                return &(*rom)[offset];
        }
}

const byte* PanasonicMemory::getRomRange(unsigned first, unsigned last)
{
        if (!rom) {
                throw MSXException("Missing PanasonicRom.");
        }
        if (last < first) {
                throw MSXException("Error in config file: firstblock must "
                                   "be smaller than lastblock");
        }
        unsigned start =  first     * 0x2000;
        if (start >= rom->getSize()) {
                throw MSXException("Error in config file: firstblock lies "
                                   "outside of rom image.");
        }
        unsigned stop  = (last + 1) * 0x2000;
        if (stop > rom->getSize()) {
                throw MSXException("Error in config file: lastblock lies "
                                   "outside of rom image.");
        }
        return &(*rom)[start];
}

byte* PanasonicMemory::getRamBlock(unsigned block)
{
        if (!ram) return nullptr;

        unsigned offset = block * 0x2000;
        if (offset >= ramSize) {
                offset &= ramSize - 1;
        }
        return ram + offset;
}

void PanasonicMemory::setDRAM(bool dram_)
{
        if (dram_ != dram) {
                dram = dram_;
                msxcpu.invalidateMemCache(0x0000, 0x10000);
        }
}

bool PanasonicMemory::isWritable(unsigned address) const
{
        return !dram || (address < (ramSize - 0x10000));
}

} // namespace openmsx