Ok, so stupid-newby question-time. Is the default thread model in nRF5 SDK 17.1.0 single threaded with exceptions, interrupts, events, running as ISRs in privileged (i.e. higher priority) stack space?
Is that specific enough, or am I being too general?
BTW, I've tried reading the nrf5 sdk documents. I'm just not finding the answer. Can anyone help?
It is an ARM Cortex-M0 core - there is no separate interrupt/exception stack. Privilege levels are independent of interrupt/thread context and optional.
Looking at the documentation, it appears to be a library to support the hardware rather then an application framework, and therefore has no particular thread model. As such nothing prevents you from using it with an RTOS of your choice. There is even a section in the documentation covering that (Libraries->RTOS support).