/*
 * 聲明：本范例源于書籍‘NiosII軟件架構(gòu)解析’
 * 作者：蔡偉綱
 * 博客地址： http://NiosII.cublog.cn 
 *
 * 一、功能: Fine-gained Flash Access驅(qū)動演示代碼.
 * 二、運(yùn)行前提: 本范例需要硬件開發(fā)板的支持,
 *     要求硬件開發(fā)板具備名為”ext_flash”的CFI Flash或EPCS Flash模塊;
*/
#include <stdio.h>
#include <string.h>
#include "sys/alt_flash.h"

#define BUF_SIZE 1024//定義緩沖區(qū)的大小
//從指定的flash分區(qū)的第OFFSET_FROM_REGION字節(jié)單元開始寫操作;
#define OFFSET_FROM_REGION 100
int main()
{
  printf("Fine-gained Flash Access Demo.\n");

  alt_flash_fd* fd;
  flash_region* regions;
  int number_of_regions;
  int ret_code;
  
//開辟源緩沖區(qū),本范例將把源緩沖區(qū)的數(shù)據(jù)寫入flash 
//BUF_SIZE不可過大,否則可能導(dǎo)致堆棧溢出; 
  char source[BUF_SIZE];
//開辟目的緩沖區(qū),本范例將把flash的數(shù)據(jù)讀回目的緩沖區(qū),
//并通過與源緩沖區(qū)數(shù)據(jù)的對比來確定讀寫flash是否正確;
//BUF_SIZE不可過大,否則可能導(dǎo)致堆棧溢出; 
  char dest[BUF_SIZE];
  
//將源緩沖區(qū)的數(shù)據(jù)全部初始化為0x55;
  memset(source, 0x55, BUF_SIZE);

//使用alt_flash_open_dev打開flash設(shè)備,并返回flash設(shè)備的文件描述器fd;
//注:flash設(shè)備在SOPC Builder中的命名應(yīng)為’ext_flash’,否則這里會出現(xiàn)編譯錯誤;
  fd = alt_flash_open_dev("/dev/ext_flash");
  if(fd!=NULL)
  {
    printf("Open Flash Device Successfully.\n");
    
  //使用alt_get_flash_info得到flash設(shè)備的分區(qū)信息;
  //關(guān)于flash分區(qū)的更詳細(xì)介紹請參考Flash設(shè)備數(shù)據(jù)結(jié)構(gòu);
    ret_code = alt_get_flash_info(fd,
                                  &regions,
                                  &number_of_regions);
  //檢查是否有可用分區(qū);
    if(number_of_regions && (regions->offset == 0))
    {
      //擦除flash設(shè)備第一個分區(qū)的第一個數(shù)據(jù)塊;
      ret_code = alt_erase_flash_block(fd,
                                       regions->offset,
                                       regions->block_size);
                                                                     
      if(ret_code == 0)
      {
        printf("Erase Flash Device Successfully.\n");
    	//將源緩沖區(qū)的數(shù)據(jù)寫入flash第一個分區(qū)的第一個數(shù)據(jù)塊;
        ret_code = alt_write_flash_block(fd,
                                         regions->offset,
										regions->offset+OFFSET_FROM_REGION,
                                         source,
                                         BUF_SIZE);
                                          
        if(ret_code == 0)
        {
          printf("Write Flash Device Successfully.\n");
      
        //使用alt_read_flash對flash設(shè)備進(jìn)行讀操作,
          ret_code = alt_read_flash(fd,                                   
                                    regions->offset+OFFSET_FROM_REGION, 
                                    dest, 
                                    BUF_SIZE);
          if(ret_code==0)
          {
            printf("Read Flash Device Successfully.\n");
    
            int Loop, ErrorCount = 0;
            for(Loop = 0; Loop < BUF_SIZE; Loop++)
            {
          	  //對比源緩沖區(qū)和目的緩沖區(qū)的數(shù)據(jù);
              if(source[Loop] != dest[Loop])
              {
                printf("Verify failed at location: 0x%X\n",Loop);
                ErrorCount++;
              }  
            }
            
            if(ErrorCount == 0)
            {
              printf("Verify Successfully!\n");
            }  
          }
          else
          {
            printf("Can’t read flash device\n");    
          }
        }
        else
        {
          printf("Can’t write flash device\n");    
        }
      }                                              
      else
      {
        printf("Can't Erase Flash Device.\n");        
      }       
    }
    else
    {
      printf("Can't Find Available Flash Region.\n");              
    }
    alt_flash_close_dev(fd);
  }
  else
  {
    printf("Can’t open flash device\n");
  }
  
  while(1);
}