open Unix
open Printf

(** http://bgb.bircd.org/pandocs.htm#thecartridgeheader *)

type memory_bank_controller =
  | ROM_ONLY
  | MBC1

type t = {
  nintendo_logo : bytes;
  title : string;
  mem_type : memory_bank_controller;
  rom_size : int;
  ram_size : int;
  header_checksum : bytes;
  global_checksum : bytes;
}

let read_cartridge file =
  print_endline file;
  let fd = openfile file [Unix.O_RDONLY] 0o644 in
  let n_logo = Bytes.create 48 in
  let _ = lseek fd 0x0104 SEEK_SET in
  let _ = read fd n_logo 0 48 in
  print_endline "Nintendo logo:";
  Hexa.print_bytes n_logo ~width:16;
  Unix.close fd