struct Memory { ~Memory(); auto operator[](uint addr) -> uint8&; auto allocate(uint size) -> void; auto copy(const uint8* data, uint size) -> void; auto free() -> void; uint8* data = nullptr; uint size = 0; }; struct MMIO { virtual auto readIO(uint16 addr) -> uint8 = 0; virtual auto writeIO(uint16 addr, uint8 data) -> void = 0; }; struct Unmapped : MMIO { auto readIO(uint16) -> uint8 { return 0xff; } auto writeIO(uint16, uint8) -> void {} }; struct Bus { auto read(uint16 addr) -> uint8; auto write(uint16 addr, uint8 data) -> void; auto power() -> void; MMIO* mmio[65536]; }; extern Unmapped unmapped; extern Bus bus;