移植U-boot，发现Nand flash启动后不能saveenv的问题，最终解决

如题，Nand flash启动后出，出现：
U-Boot 2009.08 (Dec 14 2016 - 18:01:18)
DRAM:  64 MB
Flash:  2 MB
NAND:  NAND_ECC_NONE selected by board driver. This is not recommended !!
64 MiB
*** Warning - bad CRC, using default environment
In:    serial
Out:   serial
Err:   serial
[MY2440]$
保存环境变量：
[MY2440]$saveenv
出现Nor flash保存环境变量：
Saving Environment to Flash...
Un-Protected 16 sectors
Erasing Flash...Erasing sector 64 ...
然后一直保持这种状态

查看宏定义：
//under2...for Nor boot--disable it,if it's for Nand boot-------------zh-------------
//#define CONFIG_ENV_IS_IN_FLASH        1
//#define CONFIG_ENV_SIZE                0x10000        /* Total Size of Environment Sector */
//under3...for Nand flash register&environment variables-------zh-------------
#define CONFIG_ENV_IS_IN_NAND        1
#define CONFIG_ENV_OFFSET             0x30000//save env 2 nand's 0x30000
#define CONFIG_ENV_SIZE                       0x10000//total size of env sector
并无问题
......
最后发现是编译习惯问题
编译前没有make clean
可见编译前make clean，很重要......

winboy755

学习了