[ELDK] Erasing NAND Flash rootfs and 2minutes

[J.Hwan.Kim]

Hi, everyone

I'm using ELDK 4.2 for arm and root filsystem made by following DULG.
My platform is using NAND flash as MTD device.
NAND memory map is as follows :

0x00000-200000 : ATMEL boot strap code
0x20000-60000 : U-boot
0xA0000-2A0000 : Kernel
0x2A0000-0x10000000 : Root File System

When I write root file system, I uses command in u-boot as follows:

 > tftp 0x22000000 70.7.44.102:root.jffs2
 > nand erase 0x2a0000 0xfd60000
 > nand write.jffs2 0x22000000 0x2a0000 0x3a0000

It writes well.

However, the machine operates  abnormally  during first 2minutes,
after erasing  root file system area and write  root file system.

It cannot run some system command such as "system("reboot")" in program
and also in shell. The timer seems operates 2times over than my setting.
For example , the LED  blinks  per 2second,  which  I  set  1second.

After  2minutes  after erasing flash memory, all operation come back 
normally.
For exmple, LED blinks in period I set, and "system("reboot")" works well.

Who did ever see such a case before?
I don't know what the kernel does in the first 2minutes with NAND Flash 
root file system.

How can I fix the problem?

Thanks in advance.

J.Hwan Kim