Doing driver or userland cross-development using recipes and bitbake is pretty cumbersome even with a fast machine.
If you are just porting I guess it doesn't matter.
For userland stuff, I'd recommend setting up a Makefile to point to the
cross-tools that OE built for you and run make as you would for a native
There is an example on the gumstix user-wiki here.
For kernel modules, here is a template project for an out-of-tree char dev driver you can use for Overos. It includes directions for customizing.
You can always make a recipe once development is done.