[PROBLEM] Enable serial console

[haris]

I want to see the boot messages on the serial terminal. Google search and elsewhere in this forum I got idea about using /dev/ttyAMA0.

I have latest xbian beta 2 installed on raspberry pi.
Ethernet login works great with using putty on laptop.
I have connected USB to serial converter on laptop and is wired to raspberry Pi GPIO pins 8 and 10.

Using putty on my laptop to communicate with serial connection, I have setup 115200 baud, 8 data bit, 1 stop bit, no parity and no XON/XOFF handshake.

After booting rPi with xbian, I get message on the serial terminal -
Uncompressing Linux... done, booting ...

So far I have made following changes but still no luck seeing boot messages on serial terminal.

1. I changed file /boot/cmdline.txt and added console ttyAMA0 in it as follows-
console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2

2. Changed /etc/inittab.dist and added line -
T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100

3. added modules in module file /etc/modules so that the serial terminal ttyAMA0 will show up.
serial_core
amba-pl011

After all these changes and re-booting I still do not see console messages coming on serial terminal after first line which say- "Uncompressing Linux.. Done. booting..." The fact that one line shows up on the putty console tells me USB to serial converter is set up correctly and is working fine. Can any one help me how can I get boot messages on serial terminal?
Thank you.