Domm released his port of VisualBoyAdvance for the GP2x.

This is a straight port of VisualBoyAdvance SDL. It isn’t very fast and there is no sound. Most of the time it rounds around 6fps. You can tweak frame skipping and other settings in VisualBoyAdvance.cfg.

http://www.gp2x.de/cgi-bin/cfiles.cgi?0,0,0,0,1,1018