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"
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;
  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; the libretro
  port does not implement this.

  Custom palette files (palettes/*.pal) are user-created colorization
  configs loaded when GB Colorization is set to "custom". These are
  user-generated content, not distributable files.

files:
  - name: "gb_bios.bin"
    system: nintendo-gb
    description: "Original Game Boy (DMG-01) boot ROM"
    required: false
    hle_fallback: true
    size: 256
    validation: {core: [size], upstream: [size, crc32]}
    source_ref: "libretro.cpp:1303-1363 (get_bootloader_from_file), bootloader.cpp:20-55 (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
    size: 2304
    validation: {core: [size], upstream: [size, crc32]}
    source_ref: "libretro.cpp:1303-1363 (get_bootloader_from_file), bootloader.cpp:20-55 (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."