38 lines
972 B
OCaml
38 lines
972 B
OCaml
open Bytes
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(** http://bgb.bircd.org/pandocs.htm#memorymap
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http://imrannazar.com/GameBoy-Emulation-in-JavaScript:-Memory *)
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type map = {
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rom_bank_00 : bytes; (* cartridge, 16KB *)
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rom_bank_01 : bytes; (* additional bank, 16KB *)
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vram : bytes; (* Video RAM, 8KB *)
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io : bytes; (* I/O ports *)
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}
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let init (cartridge: Cartridge.t) =
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{
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rom_bank_00 = sub cartridge.full_rom 0 0x4000;
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rom_bank_01 = create 0x4000;
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vram = create 0x2000;
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io = create 0x0080;
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}
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let get_mem_bank mem addr =
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match addr with
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| x when x < 0x4000 -> mem.rom_bank_00, x
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| x when x < 0x8000 -> mem.rom_bank_01, (x - 0x4000)
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| x when x < 0xA000 -> mem.vram, (x - 0x8000)
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| x when x < 0xFF00 -> failwith "Unimplemented memory range."
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| x when x < 0xFF80 -> mem.io, x - 0xFF00
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| _ -> failwith "Invalid memory range."
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let get mem addr =
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let m, x = get_mem_bank mem addr in
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get m x
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let set mem addr c =
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let m, x = get_mem_bank mem addr in
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set m x c
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