You need to initialize xboxdrv using the –dpad-as-button flag and use the mappings I provided. This will screw up the mappings of your other emulators, so you’ll have to remap those, but it’s the only way to get reicast to work with an xbox 360 controller.

look here for how –dpad-as-button works http://pingus.seul.org/~grumbel/xboxdrv/xboxdrv.html

and here’s the mapping I’m using. https://www.petrockblock.com/forums/topic/configuring-controllers-in-reicast/#post-99160

check my posts in this thread for more details.