DirectXBox - RetroBIOS

Type	libretro
Classification	Pure libretro
Source	https://github.com/libretro/libretro-directxbox
Version	alpha
Profiled	2026-03-23
Cores	directxbox
Systems	xbox

2 files | 2 required, 0 optional | 2 in repo, 0 missing

mcpx_1.0.bin required in repo

• Size: 512 B
• Validation: size
• Source: src/xbox.cpp:186-207, src/libretro/libretro.cpp:202
• Platforms: batocera, emudeck, recalbox, retrobat, retrodeck, rocknix, romm
• Xbox MCPX ROM (secret boot ROM on the southbridge). Contains the initial boot vector that loads the flash BIOS. Overlaid at the last 512 bytes of the 16 MB flash region (0xFFFFFE00-0xFFFFFFFF). Only needed for retail machine types; Debug and Chihiro skip this file.

cromwell_1024.bin required in repo

• Size: 1.0 MB
• Validation: size
• Source: src/xbox.cpp:143-178, src/libretro/libretro.cpp:203
• Cromwell open-source Xbox BIOS (1024 KB variant). Loaded as the flash ROM and mirrored across the 16 MB flash region at 0xFF000000. Size must be a multiple of 0x10000. This is the only BIOS that currently boots in the emulator. The Microsoft retail BIOS (xbox-3944.bin) is referenced in commented-out code but does not work yet.

Generated on 2026-09-14T09:03:09Z