选择NOR flash型号

    我的开发板上的nor flash芯片是Intel的JS28F320(4MB)(1device=32blocks,1block=128MB

fl2440默认是nandflash启动，norflash启动只需将跳线帽J5拔掉就可以了

   1. 把开发板的配置文件fl2440.h（/include/configs/fl2440.h)中关于flash的配置部分都删掉，换成下面的配置：

#define CONFIG_NR_DRAM_BANKS     1           
#define PHYS_SDRAM_1          0x30000000       
#define PHYS_SDRAM_1_SIZE     0x04000000       
#define PHYS_FLASH_1         0x00000000         
#define CFG_FLASH_BASE       PHYS_FLASH_1
#define CFG_MONITOR_BASE    TEXT_BASE
#define FLASH_BASE0_PRELIM           PHYS_FLASH_1
#define CONFIG_SYS_FLASH_PROTECTION    1
#define CFG_MAX_FLASH_BANKS     1      
#define CONFIG_SYS_FLASH_SIZE     0x00400000    
#define CFG_MAX_FLASH_SECT     32    
#define CFG_FLASH_ERASE_TOUT     (2*CONFIG_SYS_HZ)

#define CONFIG_SYS_FLASH_WRITE_TOUT     (2*CONFIG_SYS_HZ)

#define CFG_ENV_IS_IN_FLASH     1
#define CFG_ENV_SIZE         0x20000       
#define CFG_ENV_OFFSET      0x40000

#define CONFIG_SYS_HZ                   1000

#endif 

如果出现   警告： “no newline at end of file" 只需在这段代码后加几个回车就可以了

2. 把开发板目录下flash.c文件替换成下面的/board/cmi/下面的flash.c文件，然后删除这个write_short函数的申明和定义、删除write_buff函数。替换成下面的两个函数

int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
   ulong cp, wp;
   ushort data;
   int l;
   int i, rc;

   wp = (addr & ~1);      

   if ((l = addr - wp) != 0)
   {
      data = 0;
      for (i=0, cp=wp; i       data = (data >> 8) | (*(uchar *)cp << 8);
      }
      for (; i<2 && cnt>0; ++i) {
     data = (data >> 8) | (*src++ << 8);
     --cnt;
     ++cp;
      }
      for (; cnt==0 && i<2; ++i, ++cp) {
     data = (data >> 8) | (*(uchar *)cp << 8);
      }

      if ((rc = write_word(info, wp, data)) != 0) {
     return (rc);
      }
      wp += 2;
   }

   while (cnt >= 2) {
      data = *((vu_short*)src);
      if ((rc = write_word(info, wp, data)) != 0) {
      return (rc);
      }
      src += 2;
      wp  += 2;
      cnt -= 2;
   }

   if (cnt == 0) {
      return ERR_OK;
   }

   data = 0;
   for (i=0, cp=wp; i<2 && cnt>0; ++i, ++cp) {
      data = (data >> 8) | (*src++ << 8);
      --cnt;
   }
   for (; i<2; ++i, ++cp) {
      data = (data >> 8) | (*(uchar *)cp << 8);
   }

   return write_word(info, wp, data);
}

static int write_word (flash_info_t *info, ulong dest, ushort data)
{
   vu_short *addr = (vu_short *)dest, val;
   int rc = ERR_OK;
   int flag;

   if ((*addr & data) != data)
      return ERR_NOT_ERASED;

   flag = disable_interrupts();

   *addr = 0x50;

   *addr = 0x40;

   *addr = data;

   reset_timer_masked();

   while(((val = *addr) & 0x80) != 0x80)
   {
      if (get_timer_masked() > CONFIG_SYS_FLASH_WRITE_TOUT) {
      rc = ERR_TIMOUT;
      *addr = 0xB0;
      goto outahere;
      }
   }

   if(val & 0x1A) {       
      printf("nFlash write error x at address lxn",
           (int)val, (unsigned long)dest);
      if(val & (1<<3)) {
     printf("Voltage range error.n");
     rc = ERR_PROG_ERROR;
     goto outahere;
      }
      if(val & (1<<1)) {
     printf("Device protect error.n");
     rc = ERR_PROTECTED;
     goto outahere;
      }
      if(val & (1<<4)) {
     printf("Programming error.n");
     rc = ERR_PROG_ERROR;
     goto outahere;
      }
      rc = ERR_PROG_ERROR;
      goto outahere;
   }

outahere:
   *addr = 0xFF;

   if (flag)
      enable_interrupts();

   return rc;
}

   3. 修改board/fl2440/flash.c中函数申明：
static ulong flash_get_size (vu_short *addr, flash_info_t *info);
//static int write_short (flash_info_t *info, ulong dest, ushort data);
static int write_word (flash_info_t *info, ulong dest, ushort data);
static void flash_get_offsets (ulong base, flash_info_t *info);

    4. 修改flash.c文件中的一个宏定义：
把：
#define FLASH_BLOCK_SIZE        0x00010000
改为：
#define FLASH_BLOCK_SIZE        0x00020000

执行make fl2440config 和 make all将生成的U-Boot.bin烧入norflash

NOR Flash常用命令 ：查看NOR flash信息  flinfo

                    加/解写保护命令 protect

                    擦出命令    erase

                    读norflash     mm/cp

                    写norflash     cp