I have a STM32H7 Discovery kit with default setup exported, but the code stops in SystemClock_Config(). Debugger stops here: MODIFY_REG(RCC->CFGR, RCC_CFGR_SW, RCC_ClkInitStruct->SYSCLKSource) (in stm32h7xx_hal_rcc.c). Any ideas what might be a probl...