@fordsfords - Steve, who said anything about Linux? There are real real-time OSes Out There that are used by the embedded and industrial controller sectors (Rockwell Automation, Allen-Bradley, National Instruments, etc.) in every domain, such as manufacturing, assembly lines, chemical/biological processing, food processing, vehicle control ... even semiconductor fabrication (the controllers control fabbing of the devices used to make the controllers ... whoa, how meta, man!).
Of course, we need something that will run on ARM, so our choices are narrowed, and if we want open-source, they're even more limited, but surprisingly, here's that list of options: uKOS, Atomthreads, BeRTOS, BRTOS, CapROS, ChibiOS/RT, ChronOS, CoActionOS, Contiki, distortos, dnx, eCos, Embox, ERIKA Enterprise, EUROS, FreeOSEK, FreeRTOS, FunkOS, Fusion, FX, ISIX, ISIX, iRTOS, Lepton, Milos, mipOS, MMLite, MQX, Neutrino, nOS, Nucleus OS, Nut/OS, NuttX, OpenEPOS, OS21, OpenRTOS, picoOS, QP, RIOT, RTAI, RTEMS, RT-Thread, RTX Keil, scm, SDPOS, sil, T-Kernel, TI-RTOS Kernel, Trampoline, TNKernel, TNeo, TUD:OS, Unison, Xenomai, Y@SOS, and uOS (some of these may be based on real-time Linux kernels, so downloader beware).
Also, many only run on certain ARM architectures, mostly v7 and Cortex M3, and many may not be compatible with drivers for some/all of the peripherals that the C.H.I.P. has, so a lot of ferreting through docs and source would be needed. Since they are open-source though, one could theoretically stitch together a Frankenstein (C.H.I.P.enstein?) of the features needed from code that is compatible with the R8, if none of these fulfills all of your needs. It sure beats starting from scratch at the bare-metal level in assembly, unless you're already an expert or you want to learn to become one, and there's certainly nothing wrong with that.