http://hackinformer.com/2015/06/08/quic ... -tutorial/
This is for pasta. If you're using ninjhax 2.5, you'll need to search for mini-pasta. I followed this and it works great for what I needed it to. Remember it works in sysnand, so if you plan to use emunand, look up tutorials on rxtools.
Since this is a newer hack being done, not too much newer information has come about. The older 9.2 information is still mostly valid other than changes in ninjhax.
GBA emulation with dynarec access requires ninjhax 1.0. You can use injection though; linked in the tutorial to just get it working that way.
Edit: I ran mini-pasta from menuhax this morning to test. It works fine since it's based on the 2.5 hbl/ninjhax. You'll need ninjhax 1.0 based entry for the original pasta.