Re: [Xen-users] Getting stuck just before booting Dom0

["Bhaskar Muppana" <bhaskar.muppana@xxxxxxxxx>]

Hi Mark,

 

Thanks for your reply.

 

I havent logged onto the machine through serial port. I am working on the machine directly. Just to grab the xen boot messages i am using serial console. I think problem is not with serial console. Because, i am getting the same problem even if i dont redirect Xen to serial console. Please find the grub configuration i am using to boot it.

 

title Fedora (2.6.21.7-2.fc8xen-from-srpm)
        root (hd0,0)
        kernel /boot/xen.gz-2.6.21.7-2.fc8 com1=115200,8n1 sync_console noapic nolapic
        module /boot/vmlinuz-2.6.21.7-2.fc8xen ro root=LABEL=/ rhgb quiet console=ttyS0 console=tty pnpacpi=off noapic nolapic
        module /boot/initrd-2.6.21.7-2.fc8xen.img
 

I will try to explain the problem in detail..

 

I am trying to boot Xen on top of a simulator.  I found that there are few issues with APIC module of that simulator. Still, Linux is able to boot without any issues.  Xen is failing to get ccr value from APIC while booting. So, I have hardcoded this value. Now, booting is going through without any errors, but it is getting stuck just before booting into Dom0 as I mentioned in my previous mail.

 

Thanks,

Bhaskar

 

On 4/2/08, Mark Williamson <mark.williamson@xxxxxxxxxxxx> wrote:

Hi there,

>
> (XEN) ******* WARNING: CONSOLE OUTPUT IS SYNCHRONOUS

Did you set console output as synchronous whilst you were trying to debug
this?  It shouldn't do this by default...

> (XEN) Xen is relinquishing VGA console.
>
> (XEN) *** Serial input -> DOM0 (type 'CTRL-a' three times to switch input
> to Xen).  <<<<<<<<<< Nothing happens after this message
>
> </logs>

What's your configuration here?

I assume you've built your own Xen rather than using a distro-provided one?
(distros usually arrange for the configuration to Just Work, which makes them
the most straightforward option for most people).

What versions of Xen / XenLinux are you using?  How did you get them?

My guess is that dom0 just isn't sending its console output to the right
place - you're probably booting OK, you just can't see it...

Are you actually logging into this system using the serial line?  Probably
dom0's console is appearing on the physical terminal but not on the serial
line :-)

Try adding console=xvc0 (or possibly just xvc, I can't remember) to your
*Linux* kernel command line in your grub config (adding it to the Xen line
won't work!).  I think this should at least get you boot output.  You'll
probably need to add "xvc0" to /etc/securetty[s ] and add a line
to /etc/inittab if you want this to actually be useful for root login.

Alternatively, if you already have a serial line setup for vanilla Linux, try
passing "xencons=ttyS" to the Linux kernel command line, which will make the
Xen console appear like a serial device (so your existing configuration
should work).

Cheers,
Mark

--
Push Me Pull You - Distributed SCM tool (http://www.cl.cam.ac.uk/~maw48/pmpu/)

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