I’m getting the following error for certain ROMs (e.g. galaga and it’s various flavours) in MAME4ALL:
CPU 0 PC 00x: warning - op-code execute on mapped i/o
The game freezes during the boot sequence, and when I force quit using control-c the terminal is filled with these errors (with the number after PC changing). Searching for the error message doesn’t seem to bring up anything relevant (other than the MAME4ALL source code!). Anybody have any idea why it’s happening, and how I could fix it?
In case anyone else encounters this: it turns out that the error message was a bit of a red herring: the game was actually running, just incredibly slowly. So slow that it was taking around ten minutes to get past the boot sequence!
The fix was to switch from RetroArch to mame4all-pi. Now the games that were “freezing” are working great, and many of the other games that were running slowly are running full-speed.