Re: [Xen-users] [SEMI-SOLVED] XenSerialConsole help + GRUB2 (Machine locks up on boot)

[Pasi Kärkkäinen <pasik@xxxxxx>]

On Thu, Apr 15, 2010 at 11:42:59AM -0400, Mike Viau wrote:
>     > Mon, 12 Apr 2010 19:02:12 +0300 <pasik@xxxxxx> wrote:
>    >
>    > On Mon, Apr 12, 2010 at 11:55:49AM -0400, Mike Viau wrote:
>    > > > >
>    > > > > > Can you please paste the full boot messages before it locks up?
>    > > > > >
>    > > > > >
>    > > > >
>    > > > > Unfortunately no, because I am not getting any output (kernel
>    > > messages) to
>    > > > > the terminal on the other machine listening. I attached a photo of
>    > > what I
>    > > > > see on the screen when console=com1,vga.
>    > > > >
>    > > >
>    > > > So do you see the Xen hypervisor boot messages at least?
>    > > >
>    > > >
>    > >
>    > > Nothing in fact.
>    > >
>    >
>    > Please paste your grub.conf again.
>    >
>    >
> 
>    Attached is grub.cfg.
> 
>    Please notice:
> 
>    menuentry "Xen 4.0.0 / PVOPS 2.6.32-4-xen-amd64 with a serial console" {
>    insmod ext2
>    set root=(hd2,1)
>    search --fs-uuid --set 13f83e98-6e2e-48a5-992e-b266d17bbfd3
>    multiboot /xen.gz dom0_mem=2048M loglvl=all guest_loglvl=all sync_console
>    console_to_ring com1=115200,8n1,0x1000,0 console=com1
>    module /vmlinuz-2.6.32-4-xen-amd64
>    root=UUID=a8129b5a-f8cc-460e-bda4-93cc547b9f7e ro console=hvc0
>    earlyprintk=xen
>    module /initrd.img-2.6.32-4-xen-amd64
>    }
> 
> 
>    I have tried using both 0x1000 and 0x1008 with IRQ 21 and 22 and 0
> 

So do you now get Xen hypervisor boot messages? 


>    > > > > > > Motherboard:
>    > > > > > >
>    > > > >
>    > >
>    
> [4]http://www.intel.com/products/desktop/motherboards/DP55WG/DP55WG-overview.htm
>    > > > > > > [5]http://ark.intel.com/Product.aspx?id=40078
>    > > > > > >
>    > > > > > > Add-in serial card:
>    > > > > > > "Cables Unlimited IOC-2200 2-Port DB9 Serial PCI I/O Card"
>    > > > > > >
>    > > > >
>    > >
>    
> [6](http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=1431863&CatId=1422)
>    > > > > > >
>    > > > > >
>    > > > > > Does the serial console work with plain baremetal Linux?
>    (without
>    > > Xen).
>    > > > > >
>    > > > > >
>    > > > >
>    > > > > No it does not. I started a thread over on the Debian mailing-list
>    for
>    > > > > this though to see if anyone there had any ideas. I have got no
>    > > replies as
>    > > > > of yet.
>    > > > >
>    > > > > Mainly I was asking if one needed to build the mcs9865-serial.ko
>    > > (kernel
>    > > > > module) against the kernel source for the running kernel in order
>    to
>    > > log
>    > > > > kernel message during boot time or does grub implement a generic
>    > > driver to
>    > > > > capture the kernel message?
>    > > > >
>    > > >
>    > > > Uhm.. are you saying this serial-card requires some non-standard
>    driver?
>    > > > Then it probably can't be used as a serial console.
>    > > >
>    > >
>    > > I was hoping this was not the case. The Linux kernel includes drivers
>    for
>    > > serial port devices does it not? Can anyone confirm if the Moschip
>    MCS9865
>    > > is or is not supported by the Linux kernel?
>    > >
>    > > Can I try using a generic driver with this card that is already built
>    into
>    > > the Linux kernel?
>    >
>    > Yeah, sure, try it.
> 
>    What driver (name or module name) do you suggest I start with. Another
>    system has drivers like:
> 
>    8250_accent.ko         8250_exar_st16c554.ko  8250_hub6.ko
>    jsm/                   serial_cs.ko
>    8250_boca.ko           8250_fourport.ko       8250_mca.ko
>    max3100.ko
> 
>    What about serial_cs.ko?
> 
>    
> [1]http://www.google.com/#hl=en&source=hp&q=serial_cs.ko&meta=&aq=f&aqi=&aql=&oq=&gs_rfai=&fp=6909149b0ecd8aa
> 
>    > I don't know more about the serial card you have.
>    >
>    > > > The PCI serial-card needs to show up as a 'real' serial port, so
>    that
>    > > > Xen can output there boot time (before any drivers are loaded in
>    dom0
>    > > kernel).
>    > > >
>    > >
>    > > How does one determine if it is real serial port or not. No
>    /dev/ttyS[?]
>    > > devices are created in the filesystem and there is nothing in the
>    dmesg
>    > > out for these serial ports either. The PCI add-in card was advertised
>    to
>    > > be Linux compatible.
>    > >
>    >
>    > Real serial ports are available without any drivers, at boot time before
>    Linux is loaded.
>    > Xen needs to log to the serial port before _any_ drivers are loaded,
>    even before dom0 Linux is loaded.
>    >
> 
>    So the serial line use by grub 'taps' into real serial ports only right?
>    So is a driver even needed at all if all the details such as I/O address,
>    IRQ, speed, etc are provided in the grub configuration?
> 
>    Many there is a hardware limitation I am unaware or blind to see?
> 
>    > It's the same with USB-serial-adapters.. you can't use those for serial
>    console
>    > because they don't work before the driver is loaded.
>    >
>    > But yeah.. good luck!
>    >
>    > -- Pasi
>    >
> 
>    As the subject says "semi-solved."
> 
>    Used the patch found here:
> 
>    http://marc.info/?l=linux-serial&m=124975806304760
> 
>    8250_pci: add support for MCS9865
> 
>    So lesson learned Pasi, a kernel driver must be compiled with the running
>    kernel in order to capture boot messages from it. The driver does not load
>    from the bootloader or from grub itself.
> 

Ok. All the Serial Consoles I've used so far haven't required 
special/additional drivers.

-- Pasi


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users