Is there any effort yet started to support Cortex-M CPUs from GigaDevice? Specifically the Cortex-M23 part, GD32E230x.
I see there is RIOT support for their GD32VF103 series using RISC-V architecture, but my expectation is that the Cortex-M families would be quite different.
I’m not aware that someone is working on this yet, but I would actually assume them to be very similar - the peripheral drivers can probably be re-used, only the clock setup is likely a bit different (I didn’t check).
Since the GigaDevice peripherals try to be compatible with those from ST on a register level, maybe you could even add support for the GD32 ARM chips to the stm32 family, but I don’t know how big the differences are in practice, but if that would work you could get a lot of supported hardware with very little additional code.