message: make hardfault handler more easy to debug
diff: #include "stm32f4xx.h"
  #include "stm32f4xx_it.h"
  #include "cmsis_os.h"
  +#include <stdbool.h>
  /* USER CODE BEGIN 0 */
  #include <Drivers/STM32/stm32_system.h>
  @@ -85,6 +86,13 @@ void get_regs(void** stack_ptr) {
  void* volatile pc __attribute__((unused)) = stack_ptr[6]; // Program counter
  void* volatile psr __attribute__((unused)) = stack_ptr[7]; // Program status register
  + void* volatile cfsr __attribute__((unused)) = (void*)SCB->CFSR; // Configurable fault status register
  + void* volatile cpacr __attribute__((unused)) = (void*)SCB->CPACR;
  + void* volatile fpccr __attribute__((unused)) = (void*)FPU->FPCCR;
  +
  + volatile bool preciserr __attribute__((unused)) = (uint32_t)cfsr & 0x200;
  + volatile bool ibuserr __attribute__((unused)) = (uint32_t)cfsr & 0x100;
  +
  volatile int stay_looping = 1;
  while(stay_looping);
  }
  