just add NOR Flash SST39VF1601 2Mbyte for MINI2440, the effect showing as below:
U-Boot 2010.06-dirty (Aug 09 2014 - 11:02:07)

DRAM:  64 MiB
Flash: 2 MiB
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   CS8900-0
[u-boot@MINI2440] # ~

U-Boot 2010.06-dirty (Aug 09 2014 - 14:35:20)

DRAM:  64 MiB
Flash: 2 MiB
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   CS8900-0
[u-boot@MINI2440] # saveenv
Saving Environment to Flash...
Un-Protected 16 sectors
Erasing Flash...Erasing sector 64 ... ok.
Erasing sector 65 ... ok.
Erasing sector 66 ... ok.
Erasing sector 67 ... ok.
Erasing sector 68 ... ok.
Erasing sector 69 ... ok.
Erasing sector 70 ... ok.
Erasing sector 71 ... ok.
Erasing sector 72 ... ok.
Erasing sector 73 ... ok.
Erasing sector 74 ... ok.
Erasing sector 75 ... ok.
Erasing sector 76 ... ok.
Erasing sector 77 ... ok.
Erasing sector 78 ... ok.
Erasing sector 79 ... ok.
Erased 16 sectors
Writing to Flash... done
Protected 16 sectors
[u-boot@MINI2440] # reset
resetting ...

U-Boot 2010.06-dirty (Aug 09 2014 - 14:35:20)

DRAM:  64 MiB
Flash: 2 MiB
In:    serial
Out:   serial
Err:   serial
Net:   CS8900-0
[u-boot@MINI2440] #