You could consider two basic levels of support for cross compile. The first is for the kernel, because the kernel does not link to other programs…the kernel is the top of the food chain, and runs without support from anything else once booted. This only takes a cross compiler, as the kernel has built in support for doing this…it is a common task. You would need a compatible tool chain. I use Linaro on Fedora. The issue is that the current Linaro as released in binary format is version 5.2, but JTK1 was built on 4.9 compilers…I’m not sure if they would be compatible or not. If compatible, you can just download pre-built arm-linux-gnueabihf and be done…if not, you’ll need to download 4.9 source and build the chain from scratch (and it is a mighty big scratch).
The second level of cross compile is when you build applications which must exist in an environment. This means end user applications which link to libraries and co-exist in the ecosystem. There are additional downloads and builds to do this. A good substitute is to clone your Jetson and use a loopback mounted copy to provide that environment. This has a significant learning curve.
Linaro 5.2 binaries are here: