Core Paths - MiSTer-devel/Wiki_MiSTer GitHub Wiki
The standard paths are of the form /media/fat/games/<CORE>, where <CORE> is the path of the given system.
Please check the respective README file for each core to determine the appropriate full path.
They are of the form /media/usb<0..5>/games/<CORE>. Where <0..5> indicates number of the USB drive mounted by the operating system.
They are of the form /media/fat/cifs/games/<CORE>.
There are other valid paths, that are available for backwards-compatibility reasons, and also to ease testing. You should use the standard paths instead whenever possible.
There is a priority order of core paths. When you plug in a USB drive and it has a folder /games/PSX on it (mounted locally as /media/usb<0..5>/games/PSX when plugged in), then the MiSTer PSX core will look to that folder on the USB drive instead of the local one on the MicroSD at /media/fat/games/PSX. Here is the priority list from Main_MiSTer's file_io.cpp in order of highest priority to lowest:
/media/fat/media/usb<0..5>/media/usb<0..5>/games/media/fat/cifs/media/fat/cifs/games/media/fat/games
If the core's folder isn't found in any of these it should create the folder.