My project requires an adversarial scenario that an attacker cannot access the clock pin to measure the clock speed. If we have an external clock source, that implies an attacker can measure the clock externally.
I think there are others trying to do the same thing:
So I guess it is possible to build the code with a custom clock setting. I also think some ST’s code has been changed by you too. That is why I want to know whether there is an out of box way to do this.
[UPDATE] I checked the clock tree for the MCU in STM32CubeIDE, so basically there are multiple factors that will affect the system clock. Although, by default, it is 8MHz. One can change this value by PLL, PREDiv, and AHB Prescaler together with 8MHz to generate a customized-internal clock.