#include "stm32f0xx_hal.h"

/* Notes:

Need to have DFU jump right to the program to unset those option bytes, or somehow have dfu-util unset them. Probably try using the :leave parameter...

       Flashing a binary file to address 0x8004000 of device memory and ask the device to leave DFU mode:
         $ dfu-util -a 0 -s 0x08004000:leave -D /path/to/image.bin

*/


// Unset bootloader option bytes 
void bootloader_unset(void)
{
    FLASH_OBProgramInitTypeDef OBParam;
 
    HAL_FLASHEx_OBGetConfig(&OBParam);
 
    if(OBParam.USERConfig != 0xFF)
    {
 
        OBParam.OptionType = OPTIONBYTE_USER;
        OBParam.USERConfig = 0xFF;
 
        HAL_FLASH_Unlock();
        HAL_FLASH_OB_Unlock();
        HAL_FLASHEx_OBErase();
        HAL_FLASHEx_OBProgram(&OBParam);
        HAL_FLASH_OB_Lock();
        HAL_FLASH_OB_Launch();
    }
}


// See thread: https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https%3a%2f%2fmy.st.com%2fpublic%2fSTe2ecommunities%2fmcu%2fLists%2fcortex_mx_stm32%2fJump%20to%20USB%20DFU%20Bootloader%20in%20startup%20code%20on%20STM32F042&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=185
// Set option bytes to enter bootloader upon reset
void bootloader_enter(void) {

    FLASH_OBProgramInitTypeDef OBParam;
   
    HAL_FLASHEx_OBGetConfig(&OBParam);
  

    // FIXME TODO: CHECK THESE OPTION BYTES, he was using an F1 processor. What about the switch flag?
    OBParam.OptionType = OPTIONBYTE_USER;
    /*Reset NBOOT0 and BOOT_SEL,  see: RM 2.5 Boot configuration*/
    OBParam.USERConfig = 0x77; //Sorry for magic number :)
  
    HAL_FLASH_Unlock();
    HAL_FLASH_OB_Unlock();
  
    HAL_FLASHEx_OBErase();
  
    HAL_FLASHEx_OBProgram(&OBParam);
  
    HAL_FLASH_OB_Lock();
    HAL_FLASH_Lock();
  
    HAL_FLASH_OB_Launch();
}


// Clock configuration
void systemclock_init(void)
{

  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_PeriphCLKInitTypeDef PeriphClkInit;

  // Enable HSI48 for main system clock
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48|RCC_OSCILLATORTYPE_HSI14;
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
  RCC_OscInitStruct.HSI14State = RCC_HSI14_ON;
  RCC_OscInitStruct.HSI14CalibrationValue = 16;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  HAL_RCC_OscConfig(&RCC_OscInitStruct);
 

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI48;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1);

  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
  PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

  __SYSCFG_CLK_ENABLE();

}