What aspect(s) do you wish to simulate?
Stm32 microcontrollers consist of an Arm processor as well as Arm-designed and ST-designed peripherals.
But generally we then put the microcontroller into a system with other components.
Arm processor simulation is possible. But generally unnecessary - for most applications the compiler does a good job of translating source code into machine code.
Arm processor + peripherals is harder to simulate. I know Keil (commercial IDE) used to support this. But it misses two key issues. The first is how accurate the simulation is - often you only resort to simulation if hardware isn’t behaving as expected, and there are so many different versions of a peripheral in production that it’s hard for a simulator-provider to keep up. In particular how accurately does it cover “corner cases�? that don’t occur often and might not be clearly documented in the Reference Manual. And the second is that these peripherals interact directly with external hardware; what should the simulator assume about that!
And of course the system the stm32 sits in isn’t something the simulator-provider knows anything about. To make matters worse, so far we’ve only been simulating digital systems - the outside world is analog so it needs a completely different simulation engine.
(Analog problems can exist inside the stm32 as well - how should the simulator respond if you tell it to use an external crystal and then multiply that too much with the pll oscillator?)
