请教VirtualBox(host:Win7, client OS: Ubuntu) 设置KGDB 串口调试ARM开发板的问题

gaborfilter

我的系统配置如下：
VirtualBox host主机是Win7 64bit，
VirtualBox 4.2.12，
然后在其中安装了Ubuntu 12.4.2-64bit。

以前一直是利用串口输出debug信息到TeraTerm 来调式ARM开发板。现在需要用KGDB来调试一些问题。
重新编译内核以及修改uBoot后，重新启动Target开发板，从TeraTerm上的信息看到它处于等待远程连接。
{quote}
...
kgdb: Registered I/O driver kgdboc.
kgdb: Waiting for connection from remote gdb...

Entering kdb (current=0xbff8c000, pid 1) on processor 0 due to Keyboard Entry
[0]kdb>
{quote}

在host Ubuntu 下，执行 arm-***-gdb vmlinux -b 115200, 然后 target remote /dev/ttyS0， 出现以下错误：

{quote}
GNU gdb (Timesys 20130326) 7.4.1
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "--host=x86_64-linux-gnu --target=armv7l-timesys-linux-gnueabi".
For bug reporting instructions, please see:
<https://linuxlink.timesys.com/support>...
Reading symbols from /home/timesys/sabrelite/linux-3.0/vmlinux...done.
(gdb) target remote /dev/ttyS0
Remote debugging using /dev/ttyS0
Ignoring packet error, continuing...
warning: unrecognized item "timeout" in "qSupported" response
Ignoring packet error, continuing...
Ignoring packet error, continuing...
Malformed response to offset query, timeout
(gdb)

{quote}

我的VirtualBox串口设置是这样的：设置-->串口--->Port1--->Enable Serial Port ---> Port Mode: Host Pipe, check "Create　Pipe", Port/File Path: " \\.\pipe\com_1".

我google网上的一些帖子，但是始终没有找到问题所在。请问有经验的大侠指点一二。
这里先谢过了！