No MCPX ROM → no hardware initialization → no emulation.
Unlike open-source BIOS files or public domain software, the MCPX ROM is intellectual property. It cannot be legally distributed with the Xemu emulator. This creates a "gray area" common in console emulation: mcpx boot rom for xemu
The MCPX ROM’s first instruction ( 0xFFFF_FFF0 ) pointed to the right initialization routine. Xemu executed that, the ROM handed off to the BIOS, and the BIOS booted the game. No MCPX ROM → no hardware initialization → no emulation