Urs,
I have worked with TI DSPs. If this is a Dragonball, you are not going to be able to use anything but their compiler. If it isn't the Dragonball, and you can use any compiler, then you may still be running up against a brick wall, unless you can run embedded linux on the DSP (which doesn't sound likely to me.
The only way to get LabVIEW code, currently, down to processors such as this, is through a technique pioneered by Gary Johnson and his team. This involves running embedded or a small version of linux on the processor, programming in LabVIEW for linux, and downloading the whole thing to flash. He did this on a PC104, but I doubt that you can use a DSP for the same technique.
LabVIEW Realtime is another possible approach, and I recommend c
ontacting NI about that. However; my current knowledge of Realtime is that you can't download it to a DSP. I know that there are a couple of processors out there, but I don't believe a DSP is one of them.
I have been considering writing a compiler IN LabVIEW of late, but the result will be a C to machine compiler. As I don't have the source for LabVIEW (yet....bwoohahaha...just kidding of course), I have no way of being able to change the target code of LabVIEW.
However; I think that with a lot of continued prodding and badgering on the part of the developer, National Instruments may eventually cave in and expand the capabilities of LabVIEW realtime, or the application builder. However; I don't believe that you will see these upgrades in time for your project.
So, get in touch with your NI sales rep, and ask them to find out about compiling LabVIEW realtime down to your DSP. Otherwise, I don't believe you will have much luck cross compiling.