I regularly run FreeRTOS in QEMU - there are projects in the main FreeRTOS download, and this one I use to play around with connectivity: coreMQTT-Agent-Demos/build/Cortex-M3_MPS2_QEMU_GCC at main · FreeRTOS/coreMQTT-Agent-Demos · GitHub< I also run QEMU on a Windows host, with full network access. These projects are not documented as such because, today at least, they are more for code experimentation than anything else.