问题求解~~~~~~

大器所成提问时间：2015-1-11 13:02 /

static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;

  /* Select HSI48 Oscillator as PLL source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI48;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
Error_Handler();                                                                   /*原函数1 处
  }

  /* Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1)!= HAL_OK)
  {
Error_Handler();
  }                                                                                           /*原函数2处
}

原函数1：
  */
__weak HAL_StatusTypeDef HAL_RCC_OscConfig(RCC_OscInitTypeDef  *RCC_OscInitStruct)
{
  /* Note : This function is defined into this file for library reference.  */
  /*       Function content is located into file stm32f0xx_hal_rcc_ex.c to */
  /*       handle the possible oscillators present in STM32F0xx devices */

  /* Return error status as not implemented here */
  return HAL_ERROR;
}

原函数2：
__weak HAL_StatusTypeDef HAL_RCC_ClockConfig(RCC_ClkInitTypeDef  *RCC_ClkInitStruct, uint32_t FLatency)
{
  /* Note : This function is defined into this file for library reference.  */
  /*       Function content is located into file stm32f0xx_hal_rcc_ex.c to */
  /*       handle the possible oscillators present in STM32F0xx devices */

  /* Return error status as not implemented here */
  return HAL_ERROR;
}

亲爱的大侠们，我在学习STM32F072的HAL库的时候经常遇到上面有颜色的函数，这段函数具体是怎么动作的？请知道的朋友说一下吧！感谢