Microsoft - Xbox (xemu)¶

Background¶

A port of xemu, the original Xbox emulator, to libretro. The emulator is upstream's: the core follows xemu-project/xemu and reports upstream's version. It is experimental.

The core is built for Linux (x86_64, arm64), Windows (x64), macOS (Apple Silicon, Intel) and Android (arm64-v8a, x86_64).

The xemu core has been authored by

xemu-project team
Matt Borgerson
WizzardSK

The xemu core is licensed under

GPLv2

A summary of the licenses behind RetroArch and its cores can be found here.

Requirements¶

A 64-bit CPU and a GPU with OpenGL 4.0 (core profile) or Vulkan 1.1 support. The Graphics API core option picks the renderer, Vulkan by default; a change takes effect after RetroArch is restarted.

On Android the core renders with Vulkan only.
On macOS it renders with OpenGL only: MoltenVK has no geometry shaders, which xemu's Vulkan renderer needs. Use RetroArch's glcore video driver there.

BIOS¶

The core needs the console's boot ROM and BIOS and a hard disk image, none of which are included with it. Put them in an xemu folder in RetroArch's system directory.

Filename	Description	md5sum
mcpx_1.0.bin	MCPX boot ROM, 512 bytes - Required	d49c52a4102f6df7bcf8d0617ac475ed
Complex_4627v1.03.bin	Flash ROM (BIOS), 1 MB or 256 KB - Required	-
xbox_hdd.qcow2	Hard disk image - Required	-
xbox_eeprom.bin	EEPROM - Optional, created when it is missing	-

The boot ROM and the BIOS are Microsoft's and have to be dumped from your own console; see xemu's required files. A ready-made hard disk image is published by the xemu project as xemu-hdd-image.

Extensions¶

Content that can be loaded by the xemu core have the following file extensions:

.iso
.xiso

Games are loaded as XISO images, the format made by tools such as extract-xiso. A plain redump .iso of an Xbox disc has to be converted to XISO first.

Features¶

Frontend-level settings or features that the xemu core respects.

Feature	Supported
Restart	✔
Screenshots	✔
Saves	✕
States	✕
Rewind	✕
Netplay	✕
Core Options	✔
Memory Monitoring (achievements)	✕
RetroArch Cheats	✕
Native Cheats	✕
Controls	✔
Remapping	✔
Multi-Mouse	✕
Rumble	✔
Sensors	✕
Camera	✕
Location	✕
Subsystem	✕
Softpatching	✕
Disk Control	✕
Username	✕
Language	✕
Crop Overscan	✕
LEDs	✕

Games save to the emulated console's hard disk, inside xbox_hdd.qcow2, not to RetroArch save files. Save states are not supported.

Directories¶

The xemu core's library name is 'xemu'.

Frontend's System directory

xemu/mcpx_1.0.bin, xemu/Complex_4627v1.03.bin (boot ROM and BIOS)
xemu/xbox_hdd.qcow2 (hard disk image, which holds the game saves)
xemu/xbox_eeprom.bin (EEPROM)

Core options¶

The xemu core has the following option(s) that can be tweaked from the core options menu. The default setting is bolded.

System¶

System Memory (MB) [xemu_memory] (64 MB|128 MB)

Amount of system RAM. 64 MB is standard; 128 MB is used by debug kits.
Network Backend [xemu_network_backend] (Disabled|NAT)

Enable network support for Xbox games with LAN/System Link features. NAT backend provides basic connectivity.
Skip Boot Animation [xemu_skip_boot_anim] (Disabled|Enabled)

Skip the Xbox boot animation.
Hardware FPU Emulation [xemu_hard_fpu] (Enabled|Disabled)

Use host FPU for x87 emulation. Faster but may have minor inaccuracies.

Video¶

Graphics API (Restart) [xemu_renderer] (Vulkan|OpenGL)

The renderer the emulated GPU is drawn with. Vulkan is the default; OpenGL is the fallback for drivers where Vulkan misbehaves. Takes effect after RetroArch is restarted. Android always uses Vulkan, macOS always OpenGL.
Aspect Ratio [xemu_aspect_ratio] (Auto|4:3|16:9)

The shape the picture is shown in. Auto follows the game: 16:9 when it switches the console to widescreen (Widescreen has to be on in the dashboard's video settings), 4:3 otherwise. Choose 16:9 for a game that renders widescreen but is shown squashed.
Internal Resolution Scale [xemu_surface_scale] (1x (640x480)|2x (1280x960)|3x (1920x1440)|4x (2560x1920)|5x (3200x2400)|6x (3840x2880)|7x (4480x3360)|8x (5120x3840)|9x (5760x4320)|10x (6400x4800))

Scales the internal rendering resolution. Higher values improve quality but reduce performance.
AV Pack [xemu_avpack] (HDTV|Composite|S-Video|SCART|VGA)

Select the AV pack type. Affects available video modes.
Shader Cache [xemu_cache_shaders] (Enabled|Disabled)

Cache compiled GPU shaders to disk. Reduces stutter on subsequent runs.
Reduced Vulkan Buffers (Restart) [xemu_vk_reduced_buffers] (Enabled|Disabled)

The Vulkan renderer reserves its work buffers when it starts, whatever the game needs. Enabled keeps the buffer for inline vertex data at a tenth of xemu's size, which takes about 1.2 GB less video memory and as much less system memory. Disabled reserves xemu's full size on graphics cards with 4 GB or more; try it if a game is slower with this enabled.
Display Filtering [xemu_display_filtering] (Bilinear|Nearest Neighbor)

Texture filtering mode for the display output.

Audio¶

APU DSP Emulation [xemu_use_dsp] (Disabled|Enabled)

Enable DSP emulation for improved audio accuracy. May impact performance.
Audio Volume Limit (%) [xemu_audio_volume] (100%|80%|60%|40%|20%|Muted)

Limit Xbox audio output volume independently from RetroArch master volume.

Controllers¶

Up to four Xbox controllers, one per RetroArch port. Rumble goes through the frontend's rumble interface.

Joypad¶

RetroPad Inputs	Xbox controller
	A
	B
	X
	Y
	Back
	Start
	D-Pad Up
	D-Pad Down
	D-Pad Left
	D-Pad Right
	White
	Black
	Left Trigger
	Right Trigger
	Left Stick click
	Right Stick click
	Left stick
	Right stick