emulator: xemu
type: standalone + libretro
core_classification: community_fork
source:
  standalone: "https://github.com/xemu-project/xemu"
  libretro: "https://github.com/LibretroAdmin/xemu-libretro"
upstream: "https://github.com/xemu-project/xemu"
logo: "https://raw.githubusercontent.com/xemu-project/xemu/master/data/xemu_64x64.png"
profiled_date: "2026-09-17"
source_commit:
  standalone: "f9b14039e5bb56ae2d8f028e31e7cc19f13f7e12"
  libretro: "d9804db79f87f6a6a5548b14ca4a8d5164390338"
core_version:
  standalone: "0.8.136-49-gf9b14039e5"
  libretro: "libretro-experimental"
display_name: "Microsoft - Xbox (xemu)"
cores:
  - xemu
systems:
  - microsoft-xbox

notes: |
  Full-system Xbox emulator built on QEMU. One tree builds the standalone
  application and, with the libretro build option, a core in which a shim
  replaces ui/xemu.c: the QEMU machine runs on its own thread, retro_run pumps
  the RetroPads into the Duke controllers and blits the NV2A surface into the
  frontend's framebuffer through an OpenGL 4.0 core context, and content is a
  .iso or .xiso image that QEMU opens from its full path. Save states are not
  implemented; game saves live inside the hard disk image.
  ref: meson_options.txt:52-53, ui/xemu-libretro.c:1-27,
       ui/xemu-libretro.c:609-617, ui/xemu-libretro.c:680-697,
       ui/xemu-libretro.c:874-876

  Four files feed the machine through the sys.files block of the
  configuration: the MCPX boot ROM, the flash ROM, the EEPROM and the hard disk
  image. qemu_init turns them into machine arguments: bootrom= on the xbox
  machine, -bios, a smbus-storage device and an IDE drive at index 0 with
  locked=on. The standalone keeps them in xemu.toml, read from the SDL
  preference directory or from the directory of the executable when a
  xemu.toml already sits there, and the file pickers of the settings menu fill
  the four paths; nothing is searched by name and only the EEPROM has a
  default location.
  ref: config_spec.yml:353-367, system/vl.c:2983-3006, system/vl.c:3030-3074,
       ui/xemu-settings.cc:70-133, ui/xemu.c:1382-1402,
       ui/xui/main-menu.cc:1553-1575

  The core reads the same four files from the frontend system directory, each
  under a name picked by a core option that offers a default and a few
  alternatives, and keeps its configuration as xemu-libretro.toml in that
  directory. The boot ROM, the flash ROM and the disk image are opened before
  the machine starts, and a missing one fails the load with a message naming
  the file. The EEPROM is left to the machine, which generates one.
  ref: ui/xemu-libretro.c:112-127, ui/xemu-libretro.c:139-145,
       ui/xemu-libretro.c:178-236

  The standalone boots whatever it can. An unreadable flash file or a
  rejected EEPROM clears autostart and queues an error for the HUD, an
  unreadable disk image only queues the error, and an empty boot ROM path
  starts the flash without the overlay.
  ref: system/vl.c:2983-3006, system/vl.c:3030-3039, system/vl.c:3041-3053,
       system/vl.c:3060-3074, hw/xbox/xbox.c:143-165

files:
  - name: mcpx_1.0.bin
    path: mcpx_1.0.bin
    required: true
    size: 512
    validation: [size]
    config_key: sys.files.bootrom_path
    description: "MCPX boot ROM"
    note: >-
      Passed as the bootrom machine property and read over the last 512 bytes
      of the flash image, which the machine maps as a writable overlay at the
      top of the address space. qemu_init drops the path with an error when
      the file cannot be opened or is not 512 bytes, and the machine then runs
      the flash alone. The core option xemu_bootrom names the file, default
      mcpx_1.0.bin, with mcpx.bin, MCPX_1.0.bin and boot_rom.bin offered as
      alternatives; the core refuses to load when the chosen file is absent.
    source_ref:
      standalone: "system/vl.c:2983-3006, hw/xbox/xbox.c:143-171, hw/xbox/xbox.c:468-470"
      libretro: "ui/xemu-libretro.c:113-114, ui/xemu-libretro.c:192-193, ui/xemu-libretro.c:210-236"

  - name: Complex_4627.bin
    path: Complex_4627.bin
    required: true
    size: [262144, 524288, 1048576]
    validation: [size]
    size_note: "Any size that is a positive multiple of 64 KiB is mapped; the image is mirrored across the 16 MB flash window"
    config_key: sys.files.flashrom_path
    description: "Xbox flash ROM image"
    note: >-
      Passed as -bios and opened through qemu_find_file. An image whose size
      is not a multiple of 65536 bytes counts as a failed load, like a missing
      file: the 256 KB region is filled with 0xFF and the machine starts
      anyway. An unreadable path clears autostart in the standalone. The core
      option xemu_flashrom names the file, default Complex_4627.bin, with
      Complex_4627_v1.03.bin, complex_4627.bin, cerbios.bin, Cerbios.bin,
      bios.bin, xbox_bios.bin and Complex.bin offered as alternatives; the
      core refuses to load when the chosen file is absent.
    source_ref:
      standalone: "system/vl.c:3041-3053, hw/xbox/xbox.c:63-123"
      libretro: "ui/xemu-libretro.c:115-118, ui/xemu-libretro.c:195-196, ui/xemu-libretro.c:210-236"

  - name: xbox_eeprom.bin
    path: xbox_eeprom.bin
    standalone_path: eeprom.bin
    aliases: [eeprom.bin]
    required: false
    has_builtin: true
    size: 256
    validation: [size]
    config_key: sys.files.eeprom_path
    description: "Xbox EEPROM image"
    note: >-
      Attached as the smbus-storage device at address 0x54, which reads the
      whole file at realize and writes it back on every guest write. A missing
      file is generated as a retail 1.0 image with a random serial, MAC, hard
      disk key and online key, the North American region and the NTSC-M video
      standard; a file of any size other than 256 bytes is rejected and
      autostart is cleared. The standalone defaults to eeprom.bin next to
      xemu.toml. The core option xemu_eeprom names the file, default
      xbox_eeprom.bin, with eeprom.bin and EEPROM.bin offered as alternatives,
      and does not check for it before the machine starts.
    source_ref:
      standalone: "system/vl.c:2909-2949, system/vl.c:3030-3039, ui/xemu-settings.cc:135-146, hw/xbox/smbus_storage.c:56-87, hw/xbox/smbus_storage.c:90-128, hw/xbox/smbus_storage.c:155-160, hw/xbox/eeprom_generation.c:93-140"
      libretro: "ui/xemu-libretro.c:119-120, ui/xemu-libretro.c:198-199, ui/xemu-libretro.c:204-209"

  - name: xbox_hdd.qcow2
    path: xbox_hdd.qcow2
    required: true
    config_key: sys.files.hdd_path
    description: "Xbox hard disk image, 8 GB with the retail partition layout"
    note: >-
      Attached as the IDE drive at index 0 with locked=on when the path is set
      and the file opens; an unreadable file only queues an error and an empty
      path attaches no drive. Snapshots are stored inside the image. The
      project publishes a formatted image carrying its own unsigned dashboard
      and empty TDATA and UDATA folders. The core option xemu_hdd names the
      file, default xbox_hdd.qcow2, with xbox_hdd_8gb.qcow2, hdd.qcow2 and
      xbox_hdd.img offered as alternatives; the core refuses to load when the
      chosen file is absent.
    source_ref:
      standalone: "system/vl.c:3060-3074, ui/xemu-snapshots.c:156"
      libretro: "ui/xemu-libretro.c:121-123, ui/xemu-libretro.c:200-202, ui/xemu-libretro.c:210-236"

  - name: wpcap.dll
    required: false
    description: "Npcap packet capture library"
    note: >-
      Loaded by name on Windows, with every entry point resolved individually,
      when networking is enabled with the pcap backend; the netdev is not
      created when the library or one of its symbols is missing. Networking is
      off by default and the backend defaults to NAT.
    source_ref: "winpcap-loader/loader.c:79-113, ui/xemu-net.c:68-78, system/vl.c:2870-2875, config_spec.yml:327-335"

machine_properties:
  bootrom: "MCPX boot ROM path"
  avpack: "Video connector: scart, hdtv, vga, rfu, svideo, composite, none"
  short-animation: "Skip the boot animation"
  smc-version: "SMC version string, default P01"
  video-encoder: "Encoder presented to the OS: conexant, focus, xcalibur"
  source_ref: "hw/xbox/xbox.c:446-497"