emulator: Gearboy
type: libretro
core_classification: official_port
source: "https://github.com/drhelius/Gearboy"
upstream: "https://github.com/drhelius/Gearboy"
profiled_date: "2026-11-09"
source_commit: "c2beeea6e202a41f796c4026fa0caaee1b904662"
core_version: "3.8.20-11-gc2beeea"
version_basis:
  kind: tag
  tag: "3.8.20"
  distance: 11
display_name: "Nintendo - Game Boy / Color / Super Game Boy (Gearboy)"
cores:
  - gearboy
systems:
  - nintendo-gb
  - nintendo-gbc
  - nintendo-sgb

notes: |
  Gearboy is a Game Boy / Game Boy Color emulator by drhelius (Ignacio Sanchez).
  The buildbot builds from drhelius/Gearboy (upstream), not from libretro/Gearboy,
  an archived fork (its description reads "NOTE: PUBLIC ARCHIVE") whose
  src/definitions.h states version 2.6.0.
  Bootrom loading is gated behind core options (disabled by default).
  Without bootroms, the core HLE-skips the boot animation.

  Super Game Boy mode (core option gearboy_sgb, enabled by default, one
  instance only) reads the SNES cartridge ROM of the Super Game Boy,
  SGB1.sfc then SGB2.sfc in the system directory. Only its default border
  and palettes are taken from it, and SGB games run without it on the
  built-in defaults. The ROM is identified by CRC32 and size against four
  known dumps, whichever of the two names it carries, and an unknown dump
  is refused (src/SGB.cpp:38-44, 200-223, 1096-1105).

files:
  - name: dmg_boot.bin
    description: Game Boy DMG bootrom
    size: 256
    required: false
    hle_fallback: true
    validation: [size]
    source_ref: "platforms/libretro/libretro.cpp:1036-1045, platforms/libretro/libretro.cpp:474-479"

  - name: cgb_boot.bin
    description: Game Boy Color bootrom
    size: 2304
    required: false
    hle_fallback: true
    validation: [size]
    source_ref: "platforms/libretro/libretro.cpp:1047-1056, platforms/libretro/libretro.cpp:475-480"

  - name: "SGB1.sfc"
    system: nintendo-sgb
    description: "Super Game Boy SNES cartridge ROM"
    size: 262144
    crc32: ["2e35edbb", "27a03c98", "8a4a174f"]
    validation: [size, crc32]
    required: false
    hle_fallback: true
    note: "Tried first. Any of the four known dumps loads under this name, the 512 KiB SGB2 one included. Read only with Super Game Boy mode on and a single instance."
    source_ref: "platforms/libretro/libretro.cpp:447-467, platforms/libretro/libretro.cpp:879-885, src/SGB.cpp:38-44, src/SGB.cpp:200-223"

  - name: "SGB2.sfc"
    system: nintendo-sgb
    description: "Super Game Boy 2 SNES cartridge ROM"
    size: 524288
    crc32: "cb176e45"
    validation: [size, crc32]
    required: false
    hle_fallback: true
    note: "Tried when SGB1.sfc is absent or refused. Any of the four known dumps loads under this name."
    source_ref: "platforms/libretro/libretro.cpp:447-467, src/SGB.cpp:38-44, src/SGB.cpp:200-223"