omap35 出现 No console prompt seen after kernel boot

After the kernel has finished booting you may see a console message such as "Please press Enter to activate this console" and when hitting enter a console prompt appear which may be signified by a character such as "#". An example output is shown below.

Sending DHCP requests .<6>eth0: link up, 100Mbps, full-duplex, lpa 0xCDE1
., OK
IP-Config: Got DHCP answer from 255.255.255.255, my address is 128.247.107.23
IP-Config: Complete:
device=eth0, addr=128.247.107.23, mask=255.255.254.0, gw=128.247.106.2,
host=128.247.107.23, domain=am.dhcp.ti.com, nis-domain=(none),
bootserver=255.255.255.255, rootserver=128.247.107.35, rootpath=
Looking up port of RPC 100003/2 on 128.247.107.35
Looking up port of RPC 100005/1 on 128.247.107.35
VFS: Mounted root (nfs filesystem).
Freeing init memory: 136K
init started: BusyBox v1.11.1 (2008-10-05 04:40:51 CDT)
starting pid 288, tty : '/etc/init.d/rcS'

System initialization...

Hostname       : OMAP3EVM
Filesystem     : v1.0.0

Kernel release : Linux 2.6.22.18-omap3
Kernel version : #12 Mon Oct 6 01:22:49 CDT 2008

Mounting /proc             : [SUCCESS]
Mounting /sys              : [SUCCESS]
Mounting /dev              : [SUCCESS]
Mounting /dev/pts          : [SUCCESS]
Enabling hot-plug          : [SUCCESS]
Populating /dev            : [SUCCESS]
Disabling Power mgmt       : [SUCCESS]
Turn off LCD after 1 hour  : [SUCCESS]
Mounting other filesystems : [SUCCESS]
Starting syslogd           : [SUCCESS]
Starting telnetd           : [SUCCESS]

System initialization complete.

Please press Enter to activate this console.

The console message indicates that a UNIX shell has been started and you may enter commands through what is knowns as the command-line. If you do not see such a message or a prompt appear and you are unable to enter commands via the command-line after the kernel boots, then typically indicates that the start-up scripts in file-system are selecting the wrong tty interface for the console. For example, this article describes how to create a busybox root file-system for an OMAP3 device. If you refer to this section on configuring the file-system you will find that a file called /etc/inittab is created with the following contents.

::sysinit:/etc/init.d/rcS

# /bin/ash
#
# Start an "askfirst" shell on the serial port
ttyS0::askfirst:-/bin/ash

# Stuff to do when restarting the init process
::restart:/sbin/init

# Stuff to do before rebooting
::ctrlaltdel:/sbin/reboot
::shutdown:/bin/umount -a -r
::shutdown:/sbin/swapoff -a

The above file is executed once the kernel has booted and you can see near the top of the script a "askfirst" shell is launch on ttyS0. If you attempted to use this file-system as-is with a OMAP3 Beagle board that uses ttyS2 for console output then you would not see a console prompt after the kernel boots. This is easily corrected by editing the above file and changing ttyS0 to ttyS2.