text: /*
   * Copyright (c) 2018 qianfan Zhao <qianfanguijin@163.com>
   *
   * SPDX-License-Identifier: Apache-2.0
   */
  
  /**
   * @file
   * @brief System/hardware module for stm32f2 processor
   */
  
  #include <kernel.h>
  #include <device.h>
  #include <init.h>
  #include <soc.h>
  #include <arch/cpu.h>
  #include <arch/arm/cortex_m/cmsis.h>
  #include <linker/linker-defs.h>
  #include <string.h>
  
  /**
   * @brief Perform basic hardware initialization at boot.
   *
   * This needs to be run from the very beginning.
   * So the init priority has to be 0 (zero).
   *
   * @return 0
   */
  static int stm32f2_init(struct device *arg)
  {
  	u32_t key;
  
  	ARG_UNUSED(arg);
  
  	key = irq_lock();
  
  	/* Install default handler that simply resets the CPU
  	 * if configured in the kernel, NOP otherwise
  	 */
  	NMI_INIT();
  
  	irq_unlock(key);
  
  	/* Update CMSIS SystemCoreClock variable (HCLK) */
  	/* At reset, system core clock is set to 16 MHz from HSI */
  	SystemCoreClock = 16000000;
  
  	return 0;
  }
  
  SYS_INIT(stm32f2_init, PRE_KERNEL_1, 0);
  