VFS: Cannot open root device "ubi0:rootfs" or unknown-block(0,0)

Hi,

I'm using nand flash (MT29F2G08ABAEAWP) to boot my device. when booting the kernel image and file system, in the middle of booting process, the kernel panic with error VFS: Cannot open root device "ubi0:rootfs" or unknown-block(0,0).

What is this error message mean?

is it because the nand flash setting not correct ?

or my kernel configuration not correct?

Thanks and Regards

Keldy