u-boot-2009.08在mini2440上的移植 增加nand flash功能

【2】在mini2440.h里添加nand_flash相关宏定义
打开include/configs/mini2440.h，定位到98行附近，加入下列代码：
/*
 * Command line configuration.
 */
#include
#define CONFIG_CMD_CACHE
#define CONFIG_CMD_DATE
#define CONFIG_CMD_ELF
#define CONFIG_CMD_NAND
#define CONFIG_CMD_JFFS2  /* JFFS2 Support*/
... ...
在文件末尾处加入下列代码：
/*-----------------------------------------------------------------------
 * NAND flash settings
 */
#if defined(CONFIG_CMD_NAND)
#define CONFIG_NAND_S3C2410
#define CONFIG_SYS_NAND_BASE 0x4E000000
#define CONFIG_SYS_MAX_NAND_DEVICE 1 /* Max number of NAND devices  */
#define SECTORSIZE 512
#define SECTORSIZE_2K 2048
#define NAND_SECTOR_SIZE SECTORSIZE
#define NAND_SECTOR_SIZE_2K SECTORSIZE_2K
#define NAND_BLOCK_MASK 511
#define NAND_BLOCK_MASK_2K 2047
#define NAND_MAX_CHIPS 1
#define CONFIG_MTD_NAND_VERIFY_WRITE
#define CONFIG_SYS_64BIT_VSPRINTF  /* needed for nand_util.c */
#endif /* CONFIG_CMD_NAND */
#define CONFIG_S3C2410_NAND_SKIP_BAD 1
 
3.5，重新编译，按上面3.3中方法下载，运行结果如下：
 
Enter your selection: ?
U-Boot 2009.08 ( 5鏈?06 2011 - 19:52:47)
DRAM:  64 MB
Flash:  2 MB
NAND:  128 MiB
*** Warning - bad CRC, using default environment
In:    serial
Out:   serial
Err:   serial
[u-boot@MINI2440]# nand info
Device 0: NAND 128MiB 3,3V 8-bit, sector size 128 KiB
[u-boot@MINI2440]# saveenv
Saving Environment to Flash...
Un-Protected 16 sectors
Erasing Flash...Erasing sector 64 ...
从上面输出信息可以看到保存环境变量并没有成功，而且它是将把环境变量保存到Flash即Nor flash中，显然这不正确，我们是要保存到Nand中。原来，u-boot在默认的情况下把环境变量都是保存到Nor Flash中的，所以我们要修改代码，让它保存到Nand中，如下：
打开include/configs/mini2440.h，定位到193行附近，注释掉下列代码：

/* timeout values are in ticks */
#define CONFIG_SYS_FLASH_ERASE_TOUT (5*CONFIG_SYS_HZ) /* Timeout for Flash Erase */
#define CONFIG_SYS_FLASH_WRITE_TOUT (5*CONFIG_SYS_HZ) /* Timeout for Flash Write */

//#define CONFIG_ENV_IS_IN_FLASH 1
//#define CONFIG_ENV_SIZE  0x20000 /* Total Size of Environment Sector */

然后加入下列代码：

/*-----------------------------------------------------------------------
 * NAND flash settings
 */
#define CONFIG_ENV_IS_IN_NAND  1
#define CONFIG_ENV_OFFSET      0x40000 //将环境变量保存到nand中的0x40000位置必，须在块的起始位置
#define CONFIG_ENV_SIZE        0x20000 /*必须为块大小的整数倍 ， 否则会提示下面的信息，将擦除整个块*/
#if defined(CONFIG_CMD_NAND)
 
Warning: Erase size 0x00010000 smaller than one erase block 0x00020000
         Erasing 0x00020000 instead
NAND 128MiB 3,3V 8-bit: MTD Erase failure: -22
Writing to Nand... FAILED!
 
然后保存，重新编译、拨到nor 档下载，在拨到nand 档上电运行：
Enter your selection: ?
U-Boot 2009.08 ( 5鏈?06 2011 - 22:30:25)
DRAM:  64 MB
Flash:  2 MB
NAND:  128 MiB
*** Warning - bad CRC or NAND, using default environment
In:    serial
Out:   serial
Err:   serial
[u-boot@MINI2440]# saveenv
Saving Environment to NAND...
Erasing Nand...
Erasing at 0x4000000000002 --   0% complete.
Writing to Nand... done
[u-boot@MINI2440]#
可以看到环境变量保存成功，将开发板重新上电后不会再有bad CRC告警，nand flash 移植成功。

接下来将进入u-boot的第四阶段，为u-boot-2009.08增加网卡DM9000驱动支持。