[U-Boot] Prevent dropping into a shell triggered by serial port

Hi

I have connected my mini2440 to a Com device using serial port.

when I try to boot, uboot always drops into the shell. If I remove the serial port connector, it boots happily.

Looks like the Com device is responding to the boot messages from uboot and uboot is dropping into the shell.

1) Can I prevent messages from uboot into serial port

2) Can I continue to boot even if I drop into a shell (like automatically typing "boot" in the shell) with a script like .bashrc equivalent

3) can I totally shutoff the serial port for uboot only

Thanks Sunitha