[BusyBox] nothing after busybox startup

[zombit]

Hi,

I creat my ramdisk with busybox for strongarm board.
my inittab file is only 2 lines:
::sysinit:/etc/init.d/rcS
::askfirst:-/bin/sh

if /dev/ttyS0 don't exist, everything is correct.
if /dev/ttyS0 exists,

Starting kernel ...
[SKIP]
Freeing init memory: 172K                                                       
serial console detected.  Disabling virtual terminals.                          
init started:  BusyBox v0.60.0 (2001.08.28-20:31+0000) multi-call binary

message after Busybox startup is disappear.
but I know my rcS file have it's job done,
dut to my rcS brings eth0 up,
I can ping it from another manchine, so..

I also check my defconfig file, include this line:
CONFIG_CMDLINE="keepinitrd console=ttySA0"

what do I do to fix it??
any advice is welcome.

Best Reguards,
zombit