MSXMultiMemDevice.cc

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#include "MSXMultiMemDevice.hh"
#include "DummyDevice.hh"
#include "MSXCPUInterface.hh"
#include "TclObject.hh"
#include "ranges.hh"
#include "stl.hh"
#include "view.hh"
#include <cassert>
 
namespace openmsx {
 
MSXMultiMemDevice::Range::Range(
                unsigned base_, unsigned size_, MSXDevice& device_)
        : base(base_), size(size_), device(&device_)
{
}
 
 
MSXMultiMemDevice::MSXMultiMemDevice(const HardwareConfig& hwConf)
        : MSXMultiDevice(hwConf)
{
        // add sentinel at the end
        ranges.emplace_back(0x0000, 0x10000, getCPUInterface().getDummyDevice());
}
 
MSXMultiMemDevice::~MSXMultiMemDevice()
{
        assert(empty());
}
 
static constexpr bool isInside(unsigned x, unsigned start, unsigned size)
{
        return (x - start) < size;
}
 
static constexpr bool overlap(unsigned start1, unsigned size1,
                              unsigned start2, unsigned size2)
{
        return (isInside(start1,             start2, size2)) ||
               (isInside(start1 + size1 - 1, start2, size2));
}
 
bool MSXMultiMemDevice::canAdd(unsigned base, unsigned size)
{
        return ranges::none_of(view::drop_back(ranges, 1), [&](auto& rn) {
                return overlap(base, size, rn.base, rn.size);
        });
}
 
void MSXMultiMemDevice::add(MSXDevice& device, unsigned base, unsigned size)
{
        assert(canAdd(base, size));
        ranges.insert(begin(ranges), Range(base, size, device));
}
 
void MSXMultiMemDevice::remove(MSXDevice& device, unsigned base, unsigned size)
{
        ranges.erase(rfind_unguarded(ranges, Range(base, size, device)));
}
 
std::vector<MSXDevice*> MSXMultiMemDevice::getDevices() const
{
        return to_vector(view::transform(view::drop_back(ranges, 1),
                                         [](auto& rn) { return rn.device; }));
}
 
const std::string& MSXMultiMemDevice::getName() const
{
        TclObject list;
        getNameList(list);
        const_cast<std::string&>(deviceName) = list.getString();
        return deviceName;
}
void MSXMultiMemDevice::getNameList(TclObject& result) const
{
        for (const auto& r : ranges) {
                const auto& name = r.device->getName();
                if (!name.empty()) {
                        result.addListElement(name);
                }
        }
}
 
const MSXMultiMemDevice::Range& MSXMultiMemDevice::searchRange(unsigned address) const
{
        auto it = ranges::find_if(ranges, [&](const auto& r) { return isInside(address, r.base, r.size); });
        assert(it != ranges.end());
        return *it;
}
 
MSXDevice* MSXMultiMemDevice::searchDevice(unsigned address) const
{
        return searchRange(address).device;
}
 
byte MSXMultiMemDevice::readMem(word address, EmuTime::param time)
{
        return searchDevice(address)->readMem(address, time);
}
 
byte MSXMultiMemDevice::peekMem(word address, EmuTime::param time) const
{
        return searchDevice(address)->peekMem(address, time);
}
 
void MSXMultiMemDevice::writeMem(word address, byte value, EmuTime::param time)
{
        searchDevice(address)->writeMem(address, value, time);
}
 
const byte* MSXMultiMemDevice::getReadCacheLine(word start) const
{
        assert((start & CacheLine::HIGH) == start); // start is aligned
        // Because start is aligned we don't need to worry about the begin
        // address of the range. But we must make sure the end of the range
        // doesn't only fill a partial cacheline.
        const auto& range = searchRange(start);
        if (((range.base + range.size) & CacheLine::HIGH) == start) [[unlikely]] {
                // The end of this memory device only fills a partial
                // cacheline. This can't be cached.
                return nullptr;
        }
        return range.device->getReadCacheLine(start);
}
 
byte* MSXMultiMemDevice::getWriteCacheLine(word start)
{
        assert((start & CacheLine::HIGH) == start);
        const auto& range = searchRange(start);
        if (((range.base + range.size) & CacheLine::HIGH) == start) [[unlikely]] {
                return nullptr;
        }
        return range.device->getWriteCacheLine(start);
}
 
} // namespace openmsx