cross compiler / toolchain for developing native apps

Complete Arduino noob here, so go easy on me. I have a third-party product running on what's labeled "Arduino Industrial (Model DHQDH-LM05)". I want to run another process on that same processor. What I want to run is currently working on a Raspberry Pi, written in gcc c. I thought it would be a simple case of installing a cross compiler and toolchain (for MIPS?). I've installed many, and none have worked. They either say "unexpected character ")", or don't say anything at all when I run the compiled program. I've also tried to create an account on Linino.org, but I get "too many redirects" in all browsers, so I'm not sure why I can't ask questions there, but I can't. Thanks for any help you can offer.

It looks like this board was customized from 101 (Note that the logo Arduino only appears on the module.)

Please see if it helps:

https://store.arduino.cc/usa/arduino-industrial-101