emulator: PokeMini
type: libretro
source: "https://github.com/libretro/PokeMini"
profiled_date: "2026-03-18"
core_version: "v0.60"
display_name: "Nintendo - Pokemon Mini (PokeMini)"
cores:
  - pokemini
systems:
  - nintendo-pokemon-mini

notes: |
  PokeMini is a Pokemon Mini handheld emulator ported to libretro.

  The core has an embedded FreeBIOS (open-source replacement) compiled
  directly into the binary from freebios/freebios.c. This means the
  real BIOS is never strictly required -- games will run with FreeBIOS
  alone, though compatibility may differ from the original firmware.

  BIOS loading sequence in the libretro port:

  1. PokeMini_Create() clears PM_BIOS (4096 bytes at $000000-$000FFF),
     then loads FreeBIOS into it via memcpy (source/PokeMini.c:116).
     PokeMini_FreeBIOS is set to 1.

  2. retro_load_game() calls PokeMini_Reset(0) after loading the ROM.

  3. PokeMini_Reset() checks forcefreebios (hardcoded to 0 in the
     libretro port, libretro.c:499). Since FreeBIOS is currently loaded
     and forcefreebios is 0, it enters the real-BIOS path
     (source/PokeMini.c:518-523):
       - Reloads FreeBIOS as a safety fallback
       - Checks if CommandLine.bios_file exists on disk
       - If found, overwrites PM_BIOS with the real BIOS via
         PokeMini_LoadBIOSFile(), sets PokeMini_FreeBIOS to 0

  4. If bios.min is missing, FreeBIOS stays loaded and emulation
     proceeds normally.

  File path construction (libretro.c:565):
    sprintf(CommandLine.bios_file, "%s%cbios.min", g_system_dir, slash)
  The core looks for bios.min directly in the system directory root,
  no subdirectory.

  There is no core option to toggle FreeBIOS in the libretro port.
  The standalone PokeMini has a forcefreebios setting, but the libretro
  wrapper hardcodes it to 0 (always prefer real BIOS when available).

  FreeBIOS (freebios/freebios.min) is 4096 bytes, a clean-room
  reimplementation. It is NOT the official Nintendo Pokemon Mini BIOS.

files:
  - name: "bios.min"
    system: nintendo-pokemon-mini
    description: "Pokemon Mini official BIOS"
    required: false
    hle_fallback: true
    size: 4096
    md5: "1e4fb124a3a886865acb574f388c803d"
    sha1: "daad4113713ed776fbd47727762bca81ba74915f"
    source_ref: "source/PokeMini.c:189-206 (PokeMini_LoadBIOSFile), libretro/libretro.c:565 (path)"
    notes: "Mapped at $000000-$000FFF (4 KB). Read via Hardware.c:144-145. Falls back to embedded FreeBIOS if missing."

platform_details:
  bios_mapping:
    target: "$000000-$000FFF in Pokemon Mini address space (4 KB)"
    source_ref: "source/PokeMini.h:38, source/Hardware.c:144-145"
    notes: |
      PM_BIOS is a 4096-byte array. CPU reads from address range
      $000000-$000FFF are served directly from this buffer. The BIOS
      handles interrupt vectors, hardware init, and the startup logo.

  freebios_fallback:
    source_ref: "freebios/freebios.c, source/PokeMini.c:209-214"
    notes: |
      FreeBIOS is a 4096-byte open-source replacement embedded in the
      binary as a C array. It provides basic interrupt vectors and
      startup code. Loaded by default at PokeMini_Create() and used
      as fallback when bios.min is not found on disk.
    freebios_hashes:
      md5: "d6c3ff5abc88f7c42f1a5edd6889f9cf"
      sha1: "b40421defb005e836913e4e39dc1a18aa3b8887e"
      size: 4096

  load_priority:
    source_ref: "source/PokeMini.c:515-523"
    notes: |
      During PokeMini_Reset(), the core first reloads FreeBIOS as a
      safe baseline, then attempts to load bios.min from disk. If
      the file exists and is exactly 4096 bytes, it replaces FreeBIOS.
      The forcefreebios flag (hardcoded 0 in libretro) controls this:
      when 0, the core always prefers real BIOS over FreeBIOS.