Ram.cc

Go to the documentation of this file.

#include "Ram.hh"
 
#include "DeviceConfig.hh"
#include "XMLElement.hh"
#include "MSXException.hh"
 
#include "Base64.hh"
#include "HexDump.hh"
#include "narrow.hh"
#include "one_of.hh"
#include "serialize.hh"
 
#include <zlib.h>
 
#include <algorithm>
#include <bit>
 
namespace openmsx {
 
Ram::Ram(const DeviceConfig& config, const std::string& name,
         static_string_view description, size_t size)
        : xml(*config.getXML())
        , ram(size)
        , debuggable(std::in_place,
                config.getMotherBoard(), name, description, *this)
{
        clear();
}
 
Ram::Ram(const XMLElement& xml_, size_t size)
        : xml(xml_)
        , ram(size)
{
        clear();
}
 
void Ram::clear(byte c)
{
        if (const auto* init = xml.findChild("initialContent")) {
                // get pattern (and decode)
                auto encoding = init->getAttributeValue("encoding");
                size_t done = 0;
                if (encoding == "gz-base64") {
                        auto buf = Base64::decode(init->getData());
                        auto dstLen = narrow<uLongf>(size());
                        if (uncompress(std::bit_cast<Bytef*>(ram.data()), &dstLen,
                                       std::bit_cast<const Bytef*>(buf.data()), uLong(buf.size()))
                             != Z_OK) {
                                throw MSXException("Error while decompressing initialContent.");
                        }
                        done = dstLen;
                } else if (encoding == one_of("hex", "base64")) {
                        auto buf = (encoding == "hex")
                               ? HexDump::decode(init->getData())
                               : Base64 ::decode(init->getData());
                        if (buf.empty()) {
                                throw MSXException("Zero-length initial pattern");
                        }
                        done = std::min(size(), buf.size());
                        ranges::copy(buf.first(done), ram.data());
                } else {
                        throw MSXException("Unsupported encoding \"", encoding,
                                           "\" for initialContent");
                }
 
                // repeat pattern over whole ram
                auto left = size() - done;
                while (left) {
                        auto tmp = std::min(done, left);
                        ranges::copy(std::span{ram.data(), tmp}, &ram[done]);
                        done += tmp;
                        left -= tmp;
                }
        } else {
                // no init pattern specified
                ranges::fill(*this, c);
        }
}
 
const std::string& Ram::getName() const
{
        assert(debuggable);
        return debuggable->getName();
}
 
RamDebuggable::RamDebuggable(MSXMotherBoard& motherBoard_,
                             const std::string& name_,
                             static_string_view description_, Ram& ram_)
        : SimpleDebuggable(motherBoard_, name_, description_, narrow<unsigned>(ram_.size()))
        , ram(ram_)
{
}
 
byte RamDebuggable::read(unsigned address)
{
        return ram[address];
}
 
void RamDebuggable::write(unsigned address, byte value)
{
        ram[address] = value;
}
 
 
template<typename Archive>
void Ram::serialize(Archive& ar, unsigned /*version*/)
{
        // ar.serialize_blob("ram", std::span{*this}); // TODO error with clang-15/libc++
        ar.serialize_blob("ram", std::span{begin(), end()});
}
INSTANTIATE_SERIALIZE_METHODS(Ram);
 
} // namespace openmsx