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◆ main openmsx / src / memory / Ram.cc
2.9 KiB · C++ · last changed chore(): initial commit 1 month ago source blame history raw
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#include "Ram.hh"
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#include "DeviceConfig.hh"
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#include "MSXException.hh"
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#include "XMLElement.hh"
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#include "Base64.hh"
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#include "HexDump.hh"
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#include "narrow.hh"
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#include "one_of.hh"
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#include "serialize.hh"
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#include <zlib.h>
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#include <algorithm>
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#include <bit>
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namespace openmsx {
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Ram::Ram(const DeviceConfig& config, const std::string& name,
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         static_string_view description, size_t size, bool* debugWrite)
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	: xml(*config.getXML())
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	, ram(size)
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	, debuggable(std::in_place,
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		config.getMotherBoard(), name, description, *this, debugWrite ? debugWrite : &dummyDebugWrite)
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{
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	clear();
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}
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Ram::Ram(const XMLElement& xml_, size_t size)
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	: xml(xml_)
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	, ram(size)
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{
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	clear();
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}
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void Ram::clear(uint8_t c)
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{
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	if (const auto* init = xml.findChild("initialContent")) {
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		// get pattern (and decode)
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		auto encoding = init->getAttributeValue("encoding");
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		size_t done = 0;
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		if (encoding == "gz-base64") {
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			auto buf = Base64::decode(init->getData());
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			auto dstLen = narrow<uLongf>(size());
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			if (uncompress(std::bit_cast<Bytef*>(ram.data()), &dstLen,
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			               std::bit_cast<const Bytef*>(buf.data()), uLong(buf.size()))
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			     != Z_OK) {
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				throw MSXException("Error while decompressing initialContent.");
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			}
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			done = dstLen;
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		} else if (encoding == one_of("hex", "base64")) {
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			auto buf = (encoding == "hex")
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			       ? HexDump::decode(init->getData())
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			       : Base64 ::decode(init->getData());
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			if (buf.empty()) {
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				throw MSXException("Zero-length initial pattern");
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			}
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			done = std::min(size(), buf.size());
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			copy_to_range(buf.first(done), ram);
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		} else {
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			throw MSXException("Unsupported encoding \"", encoding,
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			                   "\" for initialContent");
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		}
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		// repeat pattern over whole ram
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		auto left = size() - done;
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		while (left) {
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			auto tmp = std::min(done, left);
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			copy_to_range(std::span{ram.data(), tmp}, subspan(ram, done));
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			done += tmp;
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			left -= tmp;
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		}
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	} else {
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		// no init pattern specified
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		std::ranges::fill(*this, c);
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	}
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}
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const std::string& Ram::getName() const
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{
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	assert(debuggable);
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	return debuggable->getName();
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}
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RamDebuggable::RamDebuggable(MSXMotherBoard& motherBoard_,
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                             const std::string& name_,
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                             static_string_view description_, Ram& ram_, bool* debugWrite_)
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	: SimpleDebuggable(motherBoard_, name_, description_, narrow<unsigned>(ram_.size()))
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	, ram(ram_)
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	, debugWrite(debugWrite_)
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{
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}
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uint8_t RamDebuggable::read(unsigned address)
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{
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	return ram[address];
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}
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void RamDebuggable::readBlock(unsigned start, std::span<uint8_t> output)
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{
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	copy_to_range(std::span{ram}.subspan(start, output.size()), output);
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}
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void RamDebuggable::write(unsigned address, uint8_t value)
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{
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	ram[address] = value;
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	*debugWrite = true; // for TrackedRam
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}
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template<typename Archive>
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void Ram::serialize(Archive& ar, unsigned /*version*/)
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{
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	ar.serialize_blob("ram", std::span{*this});
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}
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INSTANTIATE_SERIALIZE_METHODS(Ram);
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} // namespace openmsx