Multi-tasking without MMU: How?

[fbkr]

I'm a little late to the party but I just wanted to add that while the STM32F7 does indeed not have an MMU, it has an MPU (Memory Protection Unit) which can be used to add a rudimentary memory isolation between tasks/processes. And it's present in lots of Cortex M3 and up processors and RISC-V based ones (it's called PMP there for Physical Memory Protection).