Running Mandel.c on a Cerb40

void clock_setup(void)
{
  // This is not permissible on CERB40, b/c there's no crystal
    /* Enable high-speed clock at 120MHz */
        //rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_120MHZ]);


  /* Reset the RCC clock configuration to the default reset state ------------*/
  /* Set HSION bit */
  //RCC->CR |= (uint32_t)0x00000001;
  RCC_CR |= (uint32_t)0x00000001;

  /* Reset CFGR register */
  //RCC->CFGR = 0x00000000;
  RCC_CFGR = 0x00000000;

  /* Reset HSEON, CSSON and PLLON bits */
  //RCC->CR &= (uint32_t)0xFEF6FFFF;
  RCC_CR &= (uint32_t)0xFEF6FFFF;

  /* Reset PLLCFGR register */
  //RCC->PLLCFGR = 0x24003010;
  RCC_PLLCFGR = 0x24003010;


  /* Reset HSEBYP bit */
  //RCC->CR &= (uint32_t)0xFFFBFFFF;
  RCC_CR &= (uint32_t)0xFFFBFFFF;

  /* Disable all interrupts */
  //RCC->CIR = 0x00000000;
  RCC_CIR = 0x00000000;