>>25
"Prepackaged toolkits", meaning an arm-eabi gcc cross-compiler, a couple of tools for packaging the binary, and a selection of headers defining symbols for the addresses of the memory-mapped registers (and some other utility bits).
You can build the entire thing from gcc's source (even if you're writing raw ARM assembly, you'll still need the linker), throw in the tools to package the executable, then get hacking in whatever language you want.
Your DirectX comment indicates that you have no fucking clue what you're talking about. Enjoy your fancy Windows development platform while I use the most advanced 2D gaming platform ever designed.