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◆ main openmsx / src / memory / RomBlockDebuggable.hh
3.6 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#ifndef ROMBLOCKDEBUGGABLE_HH
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#define ROMBLOCKDEBUGGABLE_HH
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#include "MSXDevice.hh"
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#include "SimpleDebuggable.hh"
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#include "outer.hh"
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#include <span>
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namespace openmsx {
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class RomBlockDebuggableBase
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{
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public:
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	explicit RomBlockDebuggableBase(const MSXDevice& device)
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		: debuggable8 (device)
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		, debuggable16(device) {}
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	// To support larger than 8 bit segment numbers.
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	[[nodiscard]] virtual unsigned readExt(unsigned address) = 0;
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	struct Debuggable8 final : SimpleDebuggable {
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		explicit Debuggable8(const MSXDevice& device)
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			: SimpleDebuggable(device.getMotherBoard(),
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			                   device.getName() + " romblocks",
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			                   "Shows for each byte of the mapper which memory block is selected.",
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			                   0x10000) {}
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		[[nodiscard]] RomBlockDebuggableBase& getRomBlocks() {
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			return OUTER(RomBlockDebuggableBase, debuggable8);
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		}
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		[[nodiscard]] uint8_t read(unsigned address) override {
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			auto& outer = OUTER(RomBlockDebuggableBase, debuggable8);
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			return narrow_cast<uint8_t>(outer.readExt(address));
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		}
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	} debuggable8;
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	struct Debuggable16 final : SimpleDebuggable {
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		explicit Debuggable16(const MSXDevice& device)
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			: SimpleDebuggable(device.getMotherBoard(),
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			                   device.getName() + " romblocks16",
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			                   "Shows for each byte of the mapper which memory block is selected. "
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			                   "16-bit version, bits 0-7 on even / bits 8-15 on odd addresses.",
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			                   0x10000) {}
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		[[nodiscard]] uint8_t read(unsigned address) override {
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			auto& outer = OUTER(RomBlockDebuggableBase, debuggable16);
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			auto full = outer.readExt(address);
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			return narrow_cast<uint8_t>((address & 1) ? (full >> 8) : (full & 0xff));
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		}
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	} debuggable16;
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protected:
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	~RomBlockDebuggableBase() = default;
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};
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// Generic implementation. This (only) works when the segment numbers are stored
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// in some byte-array (so limited to 8-bit segment numbers).
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class RomBlockDebuggable final : public RomBlockDebuggableBase
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{
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public:
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	RomBlockDebuggable(const MSXDevice& device, std::span<const uint8_t> blockNr_,
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	                   unsigned startAddress_, unsigned mappedSize_,
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	                   unsigned bankSizeShift_, unsigned debugShift_ = 0)
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		: RomBlockDebuggableBase(device)
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		, blockNr(blockNr_.data()), startAddress(startAddress_)
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		, mappedSize(mappedSize_), bankSizeShift(bankSizeShift_)
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		, debugShift(debugShift_), debugMask(~((1 << debugShift) - 1))
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	{
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		assert((mappedSize >> bankSizeShift) == blockNr_.size()); // no need to include 'debugMask' here
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	}
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	RomBlockDebuggable(const MSXDevice& device, std::span<const uint8_t> blockNr_,
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	                   unsigned startAddress_, unsigned mappedSize_,
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	                   unsigned bankSizeShift_, unsigned debugShift_,
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	                   unsigned debugMask_)
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		: RomBlockDebuggableBase(device)
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		, blockNr(blockNr_.data()), startAddress(startAddress_)
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		, mappedSize(mappedSize_), bankSizeShift(bankSizeShift_)
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		, debugShift(debugShift_), debugMask(debugMask_)
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	{
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		assert(((mappedSize >> bankSizeShift) & debugMask) < blockNr_.size()); // here we do need 'debugMask'
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	}
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	[[nodiscard]] unsigned readExt(unsigned address) override
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	{
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		unsigned addr = address - startAddress;
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		if (addr < mappedSize) {
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			uint8_t tmp = blockNr[(addr >> bankSizeShift) & debugMask];
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			return (tmp != 255) ? (tmp >> debugShift) : tmp;
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		} else {
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			return unsigned(-1); // outside mapped address space
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		}
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	}
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private:
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	const uint8_t* blockNr;
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	const unsigned startAddress;
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	const unsigned mappedSize;
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	const unsigned bankSizeShift;
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	const unsigned debugShift;
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	const unsigned debugMask;
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};
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} // namespace openmsx
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#endif