emulator: "emux (SMS)"
type: libretro
core_classification: official_port
source: "https://github.com/libretro/emux"
upstream: "https://github.com/sronsse/emux"
profiled_date: "2026-03-23"
core_version: "0.1"
display_name: "Sega - Master System (Emux SMS)"
cores:
  - emux_sms
systems:
  - sms

notes: |
  emux is a multi-system emulator by Sebastien Ronsse. BIOS and cartridge
  code identical between upstream and libretro fork (only difference: libretro
  adds g_ram_data/g_ram_size exposure in mach/sms.c for RETRO_MEMORY_SYSTEM_RAM).

  BIOS loaded via file_map(PATH_SYSTEM, "bios.sms", 0, BIOS_SIZE) in
  sms_mapper_init (sms_mapper.c:162-165). Returns false on failure — no HLE
  fallback. Mapped at 0x0000, overlays cartridge ROM until bios_disable bit
  set in slot control register (sms_mapper.c:79-82).

  No hash validation. Code accepts any file >= 8192 bytes.
  is_experimental=true. No save states, rewind, or netplay.

files:
  - name: "bios.sms"
    system: sms
    description: "Sega Master System BIOS"
    required: true
    size: 8192
    validation: [size]
    source_ref: "controllers/mapper/sms_mapper.c:12 (BIOS_SIZE=0x2000), :61 (bios_path), :162-170 (file_map + NULL check → return false)"
    note: "Mapped at 0x0000, overlays cartridge ROM until bios_disable bit set. file_map rejects files < 8192 bytes (file.c:59)."