emulator: Gambatte
type: libretro
core_classification: community_fork
source: "https://github.com/libretro/gambatte-libretro"
upstream: "https://github.com/sinamas/gambatte"
profiled_date: "2026-03-23"
source_commit: "d9d6cd06382d1ced30de34d56d3609452323dab1"
core_version: "v0.5.0"
display_name: "Nintendo - Game Boy / Color (Gambatte)"
cores:
  - gambatte
systems: [nintendo-gb, nintendo-gbc]

notes: |
  Accuracy-focused GB/GBC emulator. No BIOS required for normal operation:
  the built-in HLE boot sequence skips the Nintendo logo animation.

  Core option gambatte_gb_bootloader (default: enabled) enables loading
  official boot ROMs from the system directory for the real startup animation.
  If missing, emulation works without them.

  Boot ROM selection by hardware mode:
  - DMG: gb_bios.bin (256 bytes)
  - CGB or GBA: gbc_bios.bin (2304 bytes)

  In GBA mode the core patches the CGB boot ROM at 0xF2 to fake GBA
  detection (ld b,0x01), enabling GBA-enhanced features in compatible
  GBC games.

  The upstream standalone supports SGB boot ROM loading, but the libretro
  port does not implement this.

  With GB Colorization set to "custom", a DMG game reads the first of
  palettes/<rom name>.pal, palettes/<header title>.pal and
  palettes/default.pal under the system directory. Each line sets one of
  the twelve background and sprite colours as Background0= to Sprite%2023=
  with a 24-bit RGB value. Colours the file leaves out keep their previous
  value (libgambatte/libretro/libretro.cpp:2012-2191,
  libgambatte/libretro/libretro.cpp:2521-2522,
  libgambatte/libretro/libretro.cpp:2582-2583).

files:
  - name: "gb_bios.bin"
    system: nintendo-gb
    description: "Original Game Boy (DMG-01) boot ROM"
    required: false
    hle_fallback: true
    min_size: 256
    validation: [size]
    source_ref: "source libgambatte/libretro/libretro.cpp:1426-1486 (get_bootloader_from_file), source libgambatte/libretro/libretro.cpp:1734-1742, source libgambatte/src/bootloader.cpp:30-65 (load)"
    note: "Mapped at 0x0000-0x00FF, swapped out when register 0xFF50 is written."

  - name: "gbc_bios.bin"
    system: nintendo-gbc
    description: "Game Boy Color (CGB-001) boot ROM"
    required: false
    hle_fallback: true
    min_size: 2304
    validation: [size]
    source_ref: "source libgambatte/libretro/libretro.cpp:1426-1486 (get_bootloader_from_file), source libgambatte/libretro/libretro.cpp:1734-1742, source libgambatte/src/bootloader.cpp:30-65 (load)"
    note: "Mapped at 0x0000-0x08FF with cartridge data preserved at 0x0100-0x01FF. Also used for GBA mode with a patch at 0xF2. Presence required for FORCE_CGB flag when hw mode is GBC or GBA."

  - name: "default.pal"
    path: "palettes/default.pal"
    system: nintendo-gb
    description: "Custom DMG colour palette"
    required: false
    unsourceable: "user-created palette, the core and its repository distribute none"
    source_ref: "source libgambatte/libretro/libretro.cpp:2012-2091, source libgambatte/libretro/libretro.cpp:2521-2522, source libgambatte/libretro/libretro.cpp:2582-2583"
    note: "Read only when GB Colorization is custom and no palette named after the ROM file or the header title exists."