I've done this for a cortex-m in qemu (meaning I wrote the chip and peripheral emulation code too for the timer, uart, sd controller with dma, and rcc). But I u

I've done this for a cortex-m in qemu (meaning I wrote the chip and peripheral emulation code too for the timer, uart, sd controller with dma, and rcc). But I used buildroot. So much easier to keep track of everything and it's very easy to start with (unlike yocto). I recommend taking a look at buildroot. You also don't need an MMU to run Linux. Just helps compatibility. Good work