I have an application written in C for a [Xilinx](http://en.wikipedia.org/wiki/Xilinx) [Microblaze](http://en.wikipedia.org/wiki/MicroBlaze) core. However, the performance isn't quite what I want so I was considering rewriting some of the core functions in assembly. I'm having trouble figuring out how to get Xilinx Platform Studio to compile both into a single [ELF](http://en.wikipedia.org/wiki/Executable_and_Linkable_Format) file though. 

How can I do it?