CrazyC has updated his port of DOSBox for Playstation Portable.

Release notes (page 2 at the release thread):

I put up a new build which attempts to auto calculate the cylinder,head,sector values. The result should have a number of sectors just slightly less then the actual on the disk. Hopefully it will also be larger then the first partition, but if not it won’t be terrible as dosbox only uses CHS for int 13h operations which very few apps use. In short, don’t try to run fdisk from within dosbox. To do it run “imgmount msstor0: -t hdd -fs fat”.