Picodrive by Notaz is a Genesis/MegaDrive and SegaCD emulator for GP2x.

Release notes:

Not much has changed from the previous version released a year ago (in terms of features), most of latest efforts were put to get it working well on Wiz. This version now runs both on Wiz and F100/F200, which will save me some burden of having to compile separate versions. Here is the changelog:

– Added Wiz support. Now the same GP2X binary supports F100/F200 and Wiz.
– Changed shadow/hilight handling a bit, fixes some effects in Pirates! Gold.
– Complete input code rewrite. This fixes some limitations like not allowing to control both players using single input device. It also allows to use more devices (like keyboards) on Linux based devices.
– Options menu has been reordered, “restore defaults” option added.
– Fixed a crash when uncompressed savestate is loaded.
– Fixed an idle loop detection related hanging problem.
– Fixed a sync problem between main and sub 68k. Should fix the hanging problem for some games.
– Fixed a crash when CD savestate is loaded just after loading ROM.

http://www.gp32x.com/board/index.php?/topic/49029-picodrive-1-55/