mirror of https://github.com/bsnes-emu/bsnes.git
96 lines
2.4 KiB
C++
96 lines
2.4 KiB
C++
//Memory
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unsigned Memory::size() const { return 0; }
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//StaticRAM
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uint8* StaticRAM::data() { return data_; }
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unsigned StaticRAM::size() const { return size_; }
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uint8 StaticRAM::read(unsigned addr) { return data_[addr]; }
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void StaticRAM::write(unsigned addr, uint8 n) { data_[addr] = n; }
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uint8& StaticRAM::operator[](unsigned addr) { return data_[addr]; }
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const uint8& StaticRAM::operator[](unsigned addr) const { return data_[addr]; }
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StaticRAM::StaticRAM(unsigned n) : size_(n) { data_ = new uint8[size_]; }
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StaticRAM::~StaticRAM() { delete[] data_; }
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//MappedRAM
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void MappedRAM::reset() {
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if(data_) {
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delete[] data_;
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data_ = nullptr;
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}
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size_ = 0;
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write_protect_ = false;
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}
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void MappedRAM::map(uint8* source, unsigned length) {
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reset();
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data_ = source;
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size_ = data_ ? length : 0;
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}
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void MappedRAM::copy(const stream& memory) {
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if(data_) delete[] data_;
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//round size up to multiple of 256-bytes
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size_ = (memory.size() & ~255) + ((bool)(memory.size() & 255) << 8);
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data_ = new uint8[size_]();
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memory.read(data_, memory.size());
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}
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void MappedRAM::read(const stream& memory) {
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memory.read(data_, min(memory.size(), size_));
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}
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void MappedRAM::write_protect(bool status) { write_protect_ = status; }
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uint8* MappedRAM::data() { return data_; }
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unsigned MappedRAM::size() const { return size_; }
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uint8 MappedRAM::read(unsigned addr) { return data_[addr]; }
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void MappedRAM::write(unsigned addr, uint8 n) { if(!write_protect_) data_[addr] = n; }
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const uint8& MappedRAM::operator[](unsigned addr) const { return data_[addr]; }
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MappedRAM::MappedRAM() : data_(nullptr), size_(0), write_protect_(false) {}
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//Bus
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unsigned Bus::mirror(unsigned addr, unsigned size) {
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if(size == 0) return 0;
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unsigned base = 0;
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unsigned mask = 1 << 23;
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while(addr >= size) {
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while(!(addr & mask)) mask >>= 1;
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addr -= mask;
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if(size > mask) {
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size -= mask;
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base += mask;
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}
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mask >>= 1;
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}
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return base + addr;
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}
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unsigned Bus::reduce(unsigned addr, unsigned mask) {
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while(mask) {
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unsigned bits = (mask & -mask) - 1;
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addr = ((addr >> 1) & ~bits) | (addr & bits);
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mask = (mask & (mask - 1)) >> 1;
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}
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return addr;
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}
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uint8 Bus::read(unsigned addr) {
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uint8 data = reader[lookup[addr]](target[addr]);
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if(cheat.enable()) {
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if(auto result = cheat.find(addr, data)) return result();
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}
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return data;
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}
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void Bus::write(unsigned addr, uint8 data) {
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return writer[lookup[addr]](target[addr], data);
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}
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