text: /**
    ******************************************************************************
    * @file    sram_diskio_template.c
    * @author  MCD Application Team
    * @version V2.0.2
    * @date    10-November-2017
    * @brief   SRAM Disk I/O template driver.This file needs to be copied under the
               application project alongside the respective header file
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics International N.V.
    * All rights reserved.</center></h2>
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted, provided that the following conditions are met:
    *
    * 1. Redistribution of source code must retain the above copyright notice,
    *    this list of conditions and the following disclaimer.
    * 2. Redistributions in binary form must reproduce the above copyright notice,
    *    this list of conditions and the following disclaimer in the documentation
    *    and/or other materials provided with the distribution.
    * 3. Neither the name of STMicroelectronics nor the names of other
    *    contributors to this software may be used to endorse or promote products
    *    derived from this software without specific written permission.
    * 4. This software, including modifications and/or derivative works of this
    *    software, must execute solely and exclusively on microcontroller or
    *    microprocessor devices manufactured by or for STMicroelectronics.
    * 5. Redistribution and use of this software other than as permitted under
    *    this license is void and will automatically terminate your rights under
    *    this license.
    *
    * THIS SOFTWARE IS PROVIDED BY STMICROELECTRONICS AND CONTRIBUTORS "AS IS"
    * AND ANY EXPRESS, IMPLIED OR STATUTORY WARRANTIES, INCLUDING, BUT NOT
    * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
    * PARTICULAR PURPOSE AND NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY
    * RIGHTS ARE DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. IN NO EVENT
    * SHALL STMICROELECTRONICS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
    * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
    * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
    * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
    * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "ff_gen_drv.h"
  #include "sram_diskio.h"
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Block Size in Bytes */
  #define BLOCK_SIZE                512
  
  /* Private variables ---------------------------------------------------------*/
  /* Disk status */
  static volatile DSTATUS Stat = STA_NOINIT;
  
  /* Private function prototypes -----------------------------------------------*/
  DSTATUS SRAMDISK_initialize (BYTE);
  DSTATUS SRAMDISK_status (BYTE);
  DRESULT SRAMDISK_read (BYTE, BYTE*, DWORD, UINT);
  #if _USE_WRITE == 1
    DRESULT SRAMDISK_write (BYTE, const BYTE*, DWORD, UINT);
  #endif /* _USE_WRITE == 1 */
  #if _USE_IOCTL == 1
    DRESULT SRAMDISK_ioctl (BYTE, BYTE, void*);
  #endif /* _USE_IOCTL == 1 */
  
  const Diskio_drvTypeDef SRAMDISK_Driver =
  {
    SRAMDISK_initialize,
    SRAMDISK_status,
    SRAMDISK_read,
  #if  _USE_WRITE == 1
    SRAMDISK_write,
  #endif /* _USE_WRITE == 1 */
  #if  _USE_IOCTL == 1
    SRAMDISK_ioctl,
  #endif /* _USE_IOCTL == 1 */
  };
  
  /* Private functions ---------------------------------------------------------*/
  
  /**
    * @brief  Initializes a Drive
    * @param  lun : not used
    * @retval DSTATUS: Operation status
    */
  DSTATUS SRAMDISK_initialize(BYTE lun)
  {
    Stat = STA_NOINIT;
  
    /* Configure the SRAM device */
    if(BSP_SRAM_Init() == SRAM_OK)
    {
       Stat &= ~STA_NOINIT;
    }
  
    return Stat;
  }
  
  /**
    * @brief  Gets Disk Status
    * @param  lun : not used
    * @retval DSTATUS: Operation status
    */
  DSTATUS SRAMDISK_status(BYTE lun)
  {
    return Stat;
  }
  
  /**
    * @brief  Reads Sector(s)
    * @param  lun : not used
    * @param  *buff: Data buffer to store read data
    * @param  sector: Sector address (LBA)
    * @param  count: Number of sectors to read (1..128)
    * @retval DRESULT: Operation result
    */
  DRESULT SRAMDISK_read(BYTE lun, BYTE *buff, DWORD sector, UINT count)
  {
    uint32_t BufferSize = (BLOCK_SIZE * count);
    uint8_t *pMem = (uint8_t *) (SRAM_DEVICE_ADDR + (sector * BLOCK_SIZE));
  
    for(; BufferSize != 0; BufferSize--)
    {
      *buff++ = *(__IO uint8_t *)pMem++;
    }
  
    return RES_OK;
  }
  
  /**
    * @brief  Writes Sector(s)
    * @param  lun : not used
    * @param  *buff: Data to be written
    * @param  sector: Sector address (LBA)
    * @param  count: Number of sectors to write (1..128)
    * @retval DRESULT: Operation result
    */
  #if _USE_WRITE == 1
  DRESULT SRAMDISK_write(BYTE lun, const BYTE *buff, DWORD sector, UINT count)
  {
    uint32_t BufferSize = (BLOCK_SIZE * count);
    uint8_t *pMem = (uint8_t *) (SRAM_DEVICE_ADDR + (sector * BLOCK_SIZE));
  
    for(; BufferSize != 0; BufferSize--)
    {
      *(__IO uint8_t *)pMem++ = *buff++;
    }
  
    return RES_OK;
  }
  #endif /* _USE_WRITE == 1 */
  
  /**
    * @brief  I/O control operation
    * @param  lun : not used
    * @param  cmd: Control code
    * @param  *buff: Buffer to send/receive control data
    * @retval DRESULT: Operation result
    */
  #if _USE_IOCTL == 1
  DRESULT SRAMDISK_ioctl(BYTE lun, BYTE cmd, void *buff)
  {
    DRESULT res = RES_ERROR;
  
    if (Stat & STA_NOINIT) return RES_NOTRDY;
  
    switch (cmd)
    {
    /* Make sure that no pending write process */
    case CTRL_SYNC :
      res = RES_OK;
      break;
  
    /* Get number of sectors on the disk (DWORD) */
    case GET_SECTOR_COUNT :
      *(DWORD*)buff = SRAM_DEVICE_SIZE / BLOCK_SIZE;
      res = RES_OK;
      break;
  
    /* Get R/W sector size (WORD) */
    case GET_SECTOR_SIZE :
      *(WORD*)buff = BLOCK_SIZE;
      res = RES_OK;
      break;
  
    /* Get erase block size in unit of sector (DWORD) */
    case GET_BLOCK_SIZE :
      *(DWORD*)buff = 1;
      res = RES_OK;
      break;
  
    default:
      res = RES_PARERR;
    }
  
    return res;
  }
  #endif /* _USE_IOCTL == 1 */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  
  