emulator: MelonDS
type: standalone + libretro
source: "https://github.com/melonDS-emu/melonDS"
logo: "https://raw.githubusercontent.com/melonDS-emu/melonDS/master/res/melon.svg"
profiled_date: "2026-03-18"
core_version: "Git"
display_name: "Nintendo - DS (melonDS)"
systems: [nintendo-ds, nintendo-dsi]

notes: |
  MelonDS includes a built-in FreeBIOS replacement for basic DS mode (NTR).
  Native BIOS/firmware files are required for DSi mode and recommended for
  full DS compatibility (Key1 crypto for cartridge auth).
  ARM9 BIOS size: 0x1000 (4 KB), ARM7 BIOS size: 0x4000 (16 KB).
  DSi BIOS size: 0x10000 (64 KB) each.
  Config keys: DS.BIOS9Path, DS.BIOS7Path, DS.FirmwarePath,
  DSi.BIOS9Path, DSi.BIOS7Path, DSi.FirmwarePath, DSi.NANDPath.

files:
  # --- Nintendo DS (NTR) ---
  - name: "bios9.bin"
    system: nintendo-ds
    description: "ARM9 BIOS (NDS mode)"
    required: false
    hle_fallback: true
    size: 4096
    crc32: "0x2ab23573"
    source_ref: "src/MemConstants.h:30,37"
    notes: "FreeBIOS fallback available; native needed for Key1 cartridge crypto (src/NDSCart.cpp:147-153)"

  - name: "bios7.bin"
    system: nintendo-ds
    description: "ARM7 BIOS (NDS mode)"
    required: false
    hle_fallback: true
    size: 16384
    crc32: "0x1280f0d5"
    source_ref: "src/MemConstants.h:31,36"
    notes: "FreeBIOS fallback available; native needed for Key1 init at offset 0x0030 (src/NDSCart.cpp:149-153)"

  - name: "firmware.bin"
    system: nintendo-ds
    description: "NDS firmware image"
    required: false
    hle_fallback: true
    source_ref: "src/frontend/qt_sdl/EmuInstance.cpp:561"
    notes: "Generated firmware used as default; native firmware needed for boot animation and wifi settings"

  # --- Nintendo DSi (TWL) ---
  - name: "dsi_bios9.bin"
    system: nintendo-dsi
    description: "ARM9i BIOS (DSi mode)"
    required: true
    size: 65536
    crc32_full: "0xBAE84F6C"
    crc32_low32k: "0x11E7C1EA"
    source_ref: "src/MemConstants.h:32,41,45"
    notes: "No FreeBIOS fallback for DSi; full dump needed for native boot (src/DSi.cpp:150-152)"

  - name: "dsi_bios7.bin"
    system: nintendo-dsi
    description: "ARM7i BIOS (DSi mode)"
    required: true
    size: 65536
    crc32_full: "0x4316CC42"
    crc32_low32k: "0x5434691D"
    source_ref: "src/MemConstants.h:32,40,44"
    notes: "Contains eMMC key-Y at offset 0x8308 used for NAND init (src/frontend/qt_sdl/EmuInstance.cpp:1044)"

  - name: "dsi_firmware.bin"
    system: nintendo-dsi
    description: "DSi firmware image"
    required: true
    source_ref: "src/frontend/qt_sdl/EmuInstance.cpp:593"
    notes: "Separate from DS firmware; config key DSi.FirmwarePath"

  - name: "dsi_nand.bin"
    system: nintendo-dsi
    description: "DSi NAND dump"
    required: true
    source_ref: "src/DSi_NAND.h:34, src/Args.h:132"
    notes: "eMMC image; uses AES keys from ARM7i BIOS and ARM9i BIOS (src/DSi_AES.cpp:94)"