emulator: Xemu
type: standalone
source: "https://github.com/xemu-project/xemu"
logo: "https://raw.githubusercontent.com/xemu-project/xemu/master/data/xemu_64x64.png"
profiled_date: "2026-03-18"
core_version: "0.8.x"
display_name: "xemu (Xbox)"
systems: [microsoft-xbox]

notes: |
  Xemu is a free, open-source Xbox emulator based on QEMU.
  Three firmware files are required for operation: MCPX boot ROM,
  flash ROM (BIOS), and EEPROM image. A pre-built HDD image is
  also needed. The EEPROM can be auto-generated by xemu if not
  provided. Config stored in xemu.toml under sys.files section.

files:
  - name: "mcpx_1.0.bin"
    description: "MCPX HLE boot ROM (v1.0)"
    required: true
    size: 512
    source_ref: "hw/xbox/xbox.c:151 (bootrom_size != 512 -> error)"
    config_key: "sys.files.bootrom_path"
    notes: |
      Overlaid on the last 512 bytes of the flash ROM region at boot.
      Mapped to 0xFFFFFE00-0xFFFFFFFF. Disabled after early init
      via LPC config register write (hw/xbox/xbox_pci.c:362).
      Machine property: -machine xbox,bootrom=<path>

  - name: "Complex_4627.bin"
    description: "Xbox flash ROM / BIOS (256 KB, kernel 4627)"
    required: true
    size_options: [262144, 524288, 1048576]
    size_note: "Must be a multiple of 64 KB. Default 256 KB."
    source_ref: "hw/xbox/xbox.c:70-81 (bios_name, bios_size validation)"
    config_key: "sys.files.flashrom_path"
    notes: |
      Loaded as -bios argument (system/vl.c:3052-3053).
      Mapped to 0xFF000000-0xFFFFFFFF with mirroring.
      Common variants: Complex_4627 (1.0), Complex_4034 (debug),
      Complex_4817 (1.1). Any valid Xbox BIOS dump works.

  - name: "eeprom.bin"
    description: "Xbox EEPROM dump (256 bytes)"
    required: false
    hle_fallback: true
    size: 256
    source_ref: "system/vl.c:2939 (size != 256 -> error)"
    config_key: "sys.files.eeprom_path"
    notes: |
      Loaded via smbus-storage device (hw/xbox/smbus_storage.c:157).
      Auto-generated as XBOX_EEPROM_VERSION_R1 if missing
      (system/vl.c:2918-2919). Default path: <config_dir>/eeprom.bin.
      Contains serial, MAC, HDD key, region, video standard.
      Structure defined in hw/xbox/eeprom_generation.h.

  - name: "xbox_hdd.qcow2"
    description: "Xbox HDD image (8 GB, qcow2 format)"
    required: true
    source_ref: "system/vl.c:3060-3073 (hdd_path loading)"
    config_key: "sys.files.hdd_path"
    notes: |
      Attached as IDE drive index=0 with locked=on.
      Must contain Xbox partitions (C, E, X, Y, Z).
      Pre-built images available from xemu project.
      Not a BIOS file - excluded from retrobios packs.

machine_properties:
  bootrom: "MCPX boot ROM path (string)"
  avpack: "Video connector type: composite, scart, svideo, vga, rfu, hdtv, none"
  short-animation: "Skip Xbox boot animation (bool)"
  smc-version: "SMC version string, 3 chars, default P01"
  video-encoder: "Video encoder chip: conexant (default), focus, xcalibur"
  source_ref: "hw/xbox/xbox.c:446-497"

memory_layout:
  ram: "64 MB or 128 MB (configurable via sys.mem_limit)"
  flash_rom: "0xFF000000-0xFFFFFFFF (mirrored per bios_size)"
  mcpx_overlay: "Last bios_size bytes, overlays flash ROM at reset"
  source_ref: "hw/xbox/xbox.c:64-173"