Very cool, thanks for sharing the info on using rust bare metal!

I'm really curious to try running rust code on the popular ESP8266 module (http://makezine.com/2015/04/01/esp8266-5-microcontroller-wi-... and http://www.esp8266.com/), but I think the board's xtensa architecture and LLVM's lack of support for it means its a non-starter. If anyone is a LLVM guru, is there any hope of compiling code for xtensa architecture and ABI? Or is there any crazy way to get LLVM to compile rust into plain old C code that can then be compiled with the modified GCC toolchain that supports the ESP8266's xtensa architecture?