I got latest MTD source code(2001-07-11 version)
 and set Kernel options.

 when the kernel booted, I found all correct messages from kernel.
 but, when I tyepd MAKEDEV, and then

 mkfs.jffs -d /home/jffs -o /tmp/jffs.image
 and

 cp /tmp/jffs.image /dev/mtd0
 the result message is

 cp: /dev/mtd0  Read-only file system.     <----Here.

 so, I can't proceed next step!!

 Could anyone explain this problem??
 Any comments will help me.. thanks.