text: // Copyright 2015-2017 Espressif Systems (Shanghai) PTE LTD
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #pragma once
  
  /**
   * @file esp_clk_internal.h
   *
   * Private clock-related functions
   */
  
  /**
   * @brief Initialize clock-related settings
   *
   * Called from cpu_start.c, not intended to be called from other places.
   * This function configures the CPU clock, RTC slow and fast clocks, and
   * performs RTC slow clock calibration.
   */
  void esp_clk_init(void);
  
  
  /**
   * @brief Disables clock of some peripherals
   *
   * Called from cpu_start.c, not intended to be called from other places.
   * This function disables clock of useless peripherals when cpu starts.
   */
  void esp_perip_clk_init(void);
  