This is really old kernel, no? Maybe you can somehow use what we do in leste?

https://github.com/maemo-leste/droid...tree/maemo-6.1

despite its name, this is actually omap kernel that runs on both 4430 (droid4) and 3430(n900). Maybe with some massaging (DTB etc) you will be able to make it boot on n9/50

also, we have https://github.com/maemo-leste/sgx-ddk-um that's up-to-date binaries from TI.

To give you some idea on the performance:
glmark-es2 hits about 87 (iirc) on droid4