MSXCPU.cc

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#include "MSXCPU.hh"
 
#include "CPUCore.hh"
#include "MSXCPUInterface.hh"
#include "R800.hh"
#include "Z80.hh"
 
#include "MSXMotherBoard.hh"
#include "Debugger.hh"
#include "Scheduler.hh"
#include "IntegerSetting.hh"
#include "TclObject.hh"
#include "serialize.hh"
 
#include "outer.hh"
#include "ranges.hh"
#include "unreachable.hh"
#include "xrange.hh"
 
#include <cassert>
#include <memory>
 
namespace openmsx {
 
MSXCPU::MSXCPU(MSXMotherBoard& motherboard_)
        : motherboard(motherboard_)
        , traceSetting(
                motherboard.getCommandController(), "cputrace",
                "CPU tracing on/off", false, Setting::Save::NO)
        , diHaltCallback(
                motherboard.getCommandController(), "di_halt_callback",
                "Tcl proc called when the CPU executed a DI/HALT sequence",
                "default_di_halt_callback",
                Setting::Save::YES) // user must be able to override
        , z80(std::make_unique<CPUCore<Z80TYPE>>(
                motherboard, "z80", traceSetting,
                diHaltCallback, EmuTime::zero()))
        , r800(motherboard.isTurboR()
                ? std::make_unique<CPUCore<R800TYPE>>(
                        motherboard, "r800", traceSetting,
                        diHaltCallback, EmuTime::zero())
                : nullptr)
        , timeInfo(motherboard.getMachineInfoCommand())
        , z80FreqInfo(motherboard.getMachineInfoCommand(), "z80_freq", *z80)
        , r800FreqInfo(r800
                ? std::make_unique<CPUFreqInfoTopic>(
                        motherboard.getMachineInfoCommand(), "r800_freq", *r800)
                : nullptr)
        , debuggable(motherboard_)
{
        motherboard.getDebugger().setCPU(this);
        motherboard.getScheduler().setCPU(this);
        traceSetting.attach(*this);
 
        z80->freqLocked.attach(*this);
        z80->freqValue.attach(*this);
        if (r800) {
                r800->freqLocked.attach(*this);
                r800->freqValue.attach(*this);
        }
        invalidateMemCacheSlot();
}
 
MSXCPU::~MSXCPU()
{
        traceSetting.detach(*this);
        z80->freqLocked.detach(*this);
        z80->freqValue.detach(*this);
        if (r800) {
                r800->freqLocked.detach(*this);
                r800->freqValue.detach(*this);
        }
        motherboard.getScheduler().setCPU(nullptr);
        motherboard.getDebugger() .setCPU(nullptr);
}
 
void MSXCPU::setInterface(MSXCPUInterface* interface_)
{
        interface = interface_;
                  z80 ->setInterface(interface);
        if (r800) r800->setInterface(interface);
}
 
void MSXCPU::doReset(EmuTime::param time)
{
                  z80 ->doReset(time);
        if (r800) r800->doReset(time);
 
        invalidateAllSlotsRWCache(0x0000, 0x10000);
 
        reference = time;
}
 
void MSXCPU::setActiveCPU(Type cpu)
{
        if (cpu == Type::R800) assert(r800);
 
        bool tmp = cpu == Type::Z80;
        if (tmp != z80Active) {
                exitCPULoopSync();
                newZ80Active = tmp;
        }
}
 
void MSXCPU::setDRAMmode(bool dram)
{
        assert(r800);
        r800->setDRAMmode(dram);
}
 
void MSXCPU::execute(bool fastForward)
{
        if (z80Active != newZ80Active) {
                EmuTime time = getCurrentTime();
                z80Active = newZ80Active;
                z80Active ? z80 ->warp(time)
                          : r800->warp(time);
                // copy Z80/R800 cache lines
                auto zCache = z80 ->getCacheLines();
                auto rCache = r800->getCacheLines();
                auto from = z80Active ? rCache : zCache;
                auto to   = z80Active ? zCache : rCache;
                ranges::copy(from.read,  to.read);
                ranges::copy(from.write, to.write);
        }
        z80Active ? z80 ->execute(fastForward)
                  : r800->execute(fastForward);
}
 
void MSXCPU::exitCPULoopSync()
{
        z80Active ? z80 ->exitCPULoopSync()
                  : r800->exitCPULoopSync();
}
void MSXCPU::exitCPULoopAsync()
{
        z80Active ? z80 ->exitCPULoopAsync()
                  : r800->exitCPULoopAsync();
}
 
EmuTime::param MSXCPU::getCurrentTime() const
{
        return z80Active ? z80 ->getCurrentTime()
                         : r800->getCurrentTime();
}
 
void MSXCPU::setNextSyncPoint(EmuTime::param time)
{
        z80Active ? z80 ->setNextSyncPoint(time)
                  : r800->setNextSyncPoint(time);
}
 
void MSXCPU::invalidateMemCacheSlot()
{
        ranges::fill(slots, 0);
 
        // nullptr: means not a valid entry and not yet attempted to fill this entry
        for (auto i : xrange(16)) {
                ranges::fill(slotReadLines[i], nullptr);
                ranges::fill(slotWriteLines[i], nullptr);
        }
}
 
void MSXCPU::updateVisiblePage(byte page, byte primarySlot, byte secondarySlot)
{
        assert(primarySlot < 4);
        assert(secondarySlot < 4);
 
        byte from = slots[page];
        byte to = narrow<byte>(4 * primarySlot + secondarySlot);
        slots[page] = to;
 
        auto [cpuReadLines, cpuWriteLines] = z80Active ? z80->getCacheLines() : r800->getCacheLines();
 
        unsigned first = page * (0x4000 / CacheLine::SIZE);
        unsigned num = 0x4000 / CacheLine::SIZE;
        std::copy_n(&cpuReadLines      [first], num, &slotReadLines [from][first]);
        std::copy_n(&slotReadLines [to][first], num, &cpuReadLines        [first]);
        std::copy_n(&cpuWriteLines     [first], num, &slotWriteLines[from][first]);
        std::copy_n(&slotWriteLines[to][first], num, &cpuWriteLines       [first]);
 
        if (r800) r800->updateVisiblePage(page, primarySlot, secondarySlot);
}
 
void MSXCPU::invalidateAllSlotsRWCache(word start, unsigned size)
{
        if (interface) interface->tick(CacheLineCounters::InvalidateAllSlots);
        auto [cpuReadLines, cpuWriteLines] = z80Active ? z80->getCacheLines() : r800->getCacheLines();
 
        unsigned first = start / CacheLine::SIZE;
        unsigned num = (size + CacheLine::SIZE - 1) / CacheLine::SIZE;
        ranges::fill(subspan(cpuReadLines,  first, num), nullptr); // nullptr: means not a valid entry and not
        ranges::fill(subspan(cpuWriteLines, first, num), nullptr); //   yet attempted to fill this entry
 
        for (auto i : xrange(16)) {
                ranges::fill(subspan(slotReadLines [i], first, num), nullptr);
                ranges::fill(subspan(slotWriteLines[i], first, num), nullptr);
        }
}
 
template<bool READ, bool WRITE, bool SUB_START>
void MSXCPU::setRWCache(unsigned start, unsigned size, const byte* rData, byte* wData, int ps, int ss,
                        std::span<const byte, 256> disallowRead,
                        std::span<const byte, 256> disallowWrite)
{
        if constexpr (!SUB_START) {
                assert(rData == nullptr);
                assert(wData == nullptr);
        }
 
        // aligned on cache lines
        assert((start & CacheLine::LOW) == 0);
        assert((size  & CacheLine::LOW) == 0);
 
        int slot = 4 * ps + ss;
        unsigned page = start >> 14;
        assert(((start + size - 1) >> 14) == page); // all in same page
        if constexpr (SUB_START && READ)  rData -= start;
        if constexpr (SUB_START && WRITE) wData -= start;
 
        // select between 'active' or 'shadow' cache lines
        auto [readLines, writeLines] = [&] {
                if (slot == slots[page]) {
                        return z80Active ? z80->getCacheLines() : r800->getCacheLines();
                } else {
                        return CacheLines{slotReadLines [slot],
                                          slotWriteLines[slot]};
                }
        }();
 
        unsigned first = start / CacheLine::SIZE;
        unsigned num = size / CacheLine::SIZE;
 
        static auto* const NON_CACHEABLE = std::bit_cast<byte*>(uintptr_t(1));
        for (auto i : xrange(num)) {
                if constexpr (READ)  readLines [first + i] = disallowRead [first + i] ? NON_CACHEABLE : rData;
                if constexpr (WRITE) writeLines[first + i] = disallowWrite[first + i] ? NON_CACHEABLE : wData;
        }
}
 
static constexpr void extendForAlignment(unsigned& start, unsigned& size)
{
        constexpr unsigned MASK = ~CacheLine::LOW; // not CacheLine::HIGH because 0x0000ff00 != 0xffffff00
 
        auto end = start + size;
        start &= MASK;                            // round down to cacheline
        end = (end + CacheLine::SIZE - 1) & MASK; // round up to cacheline
        size = end - start;
}
 
void MSXCPU::invalidateRWCache(unsigned start, unsigned size, int ps, int ss,
                               std::span<const byte, 256> disallowRead,
                               std::span<const byte, 256> disallowWrite)
{
        // unaligned [start, start+size) is OK for invalidate, then simply invalidate a little more.
        extendForAlignment(start, size);
        setRWCache<true, true, false>(start, size, nullptr, nullptr, ps, ss, disallowRead, disallowWrite);
}
void MSXCPU::invalidateRCache(unsigned start, unsigned size, int ps, int ss,
                              std::span<const byte, 256> disallowRead,
                              std::span<const byte, 256> disallowWrite)
{
        extendForAlignment(start, size);
        setRWCache<true, false, false>(start, size, nullptr, nullptr, ps, ss, disallowRead, disallowWrite);
}
void MSXCPU::invalidateWCache(unsigned start, unsigned size, int ps, int ss,
                              std::span<const byte, 256> disallowRead,
                              std::span<const byte, 256> disallowWrite)
{
        extendForAlignment(start, size);
        setRWCache<false, true, false>(start, size, nullptr, nullptr, ps, ss, disallowRead, disallowWrite);
}
 
void MSXCPU::fillRWCache(unsigned start, unsigned size, const byte* rData, byte* wData, int ps, int ss,
                         std::span<const byte, 256> disallowRead,
                         std::span<const byte, 256> disallowWrite)
{
        setRWCache<true, true, true>(start, size, rData, wData, ps, ss, disallowRead, disallowWrite);
}
void MSXCPU::fillRCache(unsigned start, unsigned size, const byte* rData, int ps, int ss,
                        std::span<const byte, 256> disallowRead,
                        std::span<const byte, 256> disallowWrite)
{
        setRWCache<true, false, true>(start, size, rData, nullptr, ps, ss, disallowRead, disallowWrite);
}
void MSXCPU::fillWCache(unsigned start, unsigned size, byte* wData, int ps, int ss,
                        std::span<const byte, 256> disallowRead,
                        std::span<const byte, 256> disallowWrite)
{
        setRWCache<false, true, true>(start, size, nullptr, wData, ps, ss, disallowRead, disallowWrite);
}
 
void MSXCPU::raiseIRQ()
{
                  z80 ->raiseIRQ();
        if (r800) r800->raiseIRQ();
}
void MSXCPU::lowerIRQ()
{
                  z80 ->lowerIRQ();
        if (r800) r800->lowerIRQ();
}
void MSXCPU::raiseNMI()
{
                  z80 ->raiseNMI();
        if (r800) r800->raiseNMI();
}
void MSXCPU::lowerNMI()
{
                  z80 ->lowerNMI();
        if (r800) r800->lowerNMI();
}
 
bool MSXCPU::isM1Cycle(unsigned address) const
{
        return z80Active ? z80 ->isM1Cycle(address)
                         : r800->isM1Cycle(address);
}
 
void MSXCPU::setZ80Freq(unsigned freq)
{
        z80->setFreq(freq);
}
 
void MSXCPU::wait(EmuTime::param time)
{
        z80Active ? z80 ->wait(time)
                  : r800->wait(time);
}
 
EmuTime MSXCPU::waitCyclesZ80(EmuTime::param time, unsigned cycles)
{
        return z80Active ? z80 ->waitCycles(time, cycles)
                         : time;
}
 
EmuTime MSXCPU::waitCyclesR800(EmuTime::param time, unsigned cycles)
{
        return z80Active ? time
                         : r800->waitCycles(time, cycles);
}
 
CPURegs& MSXCPU::getRegisters()
{
        if (z80Active) {
                return *z80;
        } else {
                return *r800;
        }
}
 
void MSXCPU::update(const Setting& setting) noexcept
{
                  z80 ->update(setting);
        if (r800) r800->update(setting);
        exitCPULoopSync();
}
 
void MSXCPU::setPaused(bool paused)
{
        if (z80Active) {
                z80 ->setExtHALT(paused);
                z80 ->exitCPULoopSync();
        } else {
                r800->setExtHALT(paused);
                r800->exitCPULoopSync();
        }
}
 
 
// class TimeInfoTopic
 
MSXCPU::TimeInfoTopic::TimeInfoTopic(InfoCommand& machineInfoCommand)
        : InfoTopic(machineInfoCommand, "time")
{
}
 
void MSXCPU::TimeInfoTopic::execute(
        std::span<const TclObject> /*tokens*/, TclObject& result) const
{
        const auto& cpu = OUTER(MSXCPU, timeInfo);
        EmuDuration dur = cpu.getCurrentTime() - cpu.reference;
        result = dur.toDouble();
}
 
std::string MSXCPU::TimeInfoTopic::help(std::span<const TclObject> /*tokens*/) const
{
        return "Prints the time in seconds that the MSX is powered on\n";
}
 
 
// class CPUFreqInfoTopic
 
MSXCPU::CPUFreqInfoTopic::CPUFreqInfoTopic(
                InfoCommand& machineInfoCommand,
                const std::string& name_, CPUClock& clock_)
        : InfoTopic(machineInfoCommand, name_)
        , clock(clock_)
{
}
 
void MSXCPU::CPUFreqInfoTopic::execute(
        std::span<const TclObject> /*tokens*/, TclObject& result) const
{
        result = clock.getFreq();
}
 
std::string MSXCPU::CPUFreqInfoTopic::help(std::span<const TclObject> /*tokens*/) const
{
        return "Returns the actual frequency of this CPU.\n"
               "This frequency can vary because:\n"
               " - the user has overridden the freq via the '{z80,r800}_freq' setting\n"
               " - (only on some MSX machines) the MSX software can switch the Z80 between 2 frequencies\n"
               "See also the '{z80,r800}_freq_locked' setting.\n";
}
 
 
// class Debuggable
 
static constexpr static_string_view CPU_REGS_DESC =
        "Registers of the active CPU (Z80 or R800).\n"
        "Each byte in this debuggable represents one 8 bit register:\n"
        "  0 ->  A      1 ->  F      2 -> B       3 -> C\n"
        "  4 ->  D      5 ->  E      6 -> H       7 -> L\n"
        "  8 ->  A'     9 ->  F'    10 -> B'     11 -> C'\n"
        " 12 ->  D'    13 ->  E'    14 -> H'     15 -> L'\n"
        " 16 -> IXH    17 -> IXL    18 -> IYH    19 -> IYL\n"
        " 20 -> PCH    21 -> PCL    22 -> SPH    23 -> SPL\n"
        " 24 ->  I     25 ->  R     26 -> IM     27 -> IFF1/2\n"
        "The last position (27) contains the IFF1 and IFF2 flags in respectively\n"
        "bit 0 and 1. Bit 2 contains 'IFF1 AND last-instruction-was-not-EI', so\n"
        "this effectively indicates that the CPU could accept an interrupt at\n"
        "the start of the current instruction.\n";
 
MSXCPU::Debuggable::Debuggable(MSXMotherBoard& motherboard_)
        : SimpleDebuggable(motherboard_, "CPU regs", CPU_REGS_DESC, 28)
{
}
 
byte MSXCPU::Debuggable::read(unsigned address)
{
        auto& cpu = OUTER(MSXCPU, debuggable);
        const CPURegs& regs = cpu.getRegisters();
        switch (address) {
        case  0: return regs.getA();
        case  1: return regs.getF();
        case  2: return regs.getB();
        case  3: return regs.getC();
        case  4: return regs.getD();
        case  5: return regs.getE();
        case  6: return regs.getH();
        case  7: return regs.getL();
        case  8: return regs.getA2();
        case  9: return regs.getF2();
        case 10: return regs.getB2();
        case 11: return regs.getC2();
        case 12: return regs.getD2();
        case 13: return regs.getE2();
        case 14: return regs.getH2();
        case 15: return regs.getL2();
        case 16: return regs.getIXh();
        case 17: return regs.getIXl();
        case 18: return regs.getIYh();
        case 19: return regs.getIYl();
        case 20: return regs.getPCh();
        case 21: return regs.getPCl();
        case 22: return regs.getSPh();
        case 23: return regs.getSPl();
        case 24: return regs.getI();
        case 25: return regs.getR();
        case 26: return regs.getIM();
        case 27: return byte(1 *  regs.getIFF1() +
                             2 *  regs.getIFF2() +
                             4 * (regs.getIFF1() && !regs.prevWasEI()));
        default: UNREACHABLE;
        }
}
 
void MSXCPU::Debuggable::write(unsigned address, byte value)
{
        auto& cpu = OUTER(MSXCPU, debuggable);
        CPURegs& regs = cpu.getRegisters();
        switch (address) {
        case  0: regs.setA(value); break;
        case  1: regs.setF(value); break;
        case  2: regs.setB(value); break;
        case  3: regs.setC(value); break;
        case  4: regs.setD(value); break;
        case  5: regs.setE(value); break;
        case  6: regs.setH(value); break;
        case  7: regs.setL(value); break;
        case  8: regs.setA2(value); break;
        case  9: regs.setF2(value); break;
        case 10: regs.setB2(value); break;
        case 11: regs.setC2(value); break;
        case 12: regs.setD2(value); break;
        case 13: regs.setE2(value); break;
        case 14: regs.setH2(value); break;
        case 15: regs.setL2(value); break;
        case 16: regs.setIXh(value); break;
        case 17: regs.setIXl(value); break;
        case 18: regs.setIYh(value); break;
        case 19: regs.setIYl(value); break;
        case 20: regs.setPCh(value); break;
        case 21: regs.setPCl(value); break;
        case 22: regs.setSPh(value); break;
        case 23: regs.setSPl(value); break;
        case 24: regs.setI(value); break;
        case 25: regs.setR(value); break;
        case 26:
                if (value < 3) regs.setIM(value);
                break;
        case 27:
                regs.setIFF1((value & 0x01) != 0);
                regs.setIFF2((value & 0x02) != 0);
                // can't change afterEI
                break;
        default:
                UNREACHABLE;
        }
}
 
// version 1: initial version
// version 2: activeCPU,newCPU -> z80Active,newZ80Active
template<typename Archive>
void MSXCPU::serialize(Archive& ar, unsigned version)
{
        if (ar.versionAtLeast(version, 2)) {
                          ar.serialize("z80",  *z80);
                if (r800) ar.serialize("r800", *r800);
                ar.serialize("z80Active",    z80Active,
                             "newZ80Active", newZ80Active);
        } else {
                // backwards-compatibility
                assert(Archive::IS_LOADER);
 
                          ar.serializeWithID("z80",  *z80);
                if (r800) ar.serializeWithID("r800", *r800);
                CPUBase* activeCPU = nullptr;
                CPUBase* newCPU = nullptr;
                ar.serializePointerID("activeCPU", activeCPU);
                ar.serializePointerID("newCPU",    newCPU);
                z80Active = activeCPU == z80.get();
                if (newCPU) {
                        newZ80Active = newCPU == z80.get();
                } else {
                        newZ80Active = z80Active;
                }
        }
        ar.serialize("resetTime", reference);
 
        if constexpr (Archive::IS_LOADER) {
                invalidateMemCacheSlot();
                invalidateAllSlotsRWCache(0x0000, 0x10000);
        }
}
INSTANTIATE_SERIALIZE_METHODS(MSXCPU);
 
} // namespace openmsx