On Thu, Jun 7, 2012 at 5:27 PM, Rolu <rolu@xxxxxxxx>
wrote:
On Thu, Jun 7, 2012 at 3:15 PM, Rolu <rolu@xxxxxxxx>
wrote:
> I've compiled Xen unstable from source and tried using
it. When
> booting I do see Xen starting, but at the point where I
normally start
> getting the dom0 kernel messages I just get a black
screen for a few
> seconds, and then the machine reboots. It leaves no
messages or log
> files, of course.
>
> revision I compiled: 25459
> OS: ubuntu 12.04
> dom0 kernel 3.2.0-24 (also tried -23), from the
repositories. This
> kernel works with Xen 4.1 from the repositories.
>
> I had to apply the patch from
> http://lists.gnu.org/archive/html/qemu-devel/2012-02/msg03460.html
to
> get it to compile. Could this have broken something?
>
> Is there a way to have it display some log messages
instead of rebooting?
Well possibly, yes. I had a similar issue before and when i compiled
and installed xen. But once i tried booting into Xen, it would just
hang at a black screen, nothing on it. Sometimes it would show a
rapidly flickering cursor, but that's it.
SO, what i had to try was to enable the Xen serial console. What
this entails is using a NULL MODEM cable and plugging this into the
COM port on your XEN computer and connecting the other end to a
second computers COM port. Than you have to use a Terminal program,
just as PuTTY or similar (based on your OS on second computer) and
this way you can watch the Xen boot messages as they happen and
could possibly troubleshoot.
To enable the Serial Console, just have to add "loglvl=all
guest_loglvl=all com1=115200,8n1,0x3f8,4 console=com1,vga" after the
"multiboot /boot/xen-4.2-unstable.gz placeholder ... "
Personally, I tried this. I bought a pci serial card and a null modem
cable. I attached the cable between my card and the usb-pci adapter
connected to my laptop. I set the grub to: multiboot /boot/xen-4.2.gz placeholder loglvl=all guest_loglvl=all com5=38400,8n1,0xa030,20 console=com5
and started minicom on the labtop. Noting came up on minicom, and
nothing came up on the desktop's screen (As should be expected).
I tested the connection by running minicom on the desktop as well. That works fine. My output to dmesg | grep ttyS is:
[ 2.393378] 0000:08:05.0: ttyS4 at I/O 0xa030 (irq = 20) is a ST16650V2
[ 2.449062] 0000:08:05.1: ttyS5 at I/O 0xa020 (irq = 21) is a ST16650V2 If anyone knows why my serial console isn't working, maybe I can fix it and get some useful information to debug this problem.
>
> Any idea how to get it to work?
>
> If anyone else here is successfully using a recent
revision, can you
> tell me which one, so I can try it too?
>
I've tried revision 25364 and 25099 (both picked because I
found
someone reporting they worked for them). I got both to compile
with
one or two patches, but with the same result.
I have the same issue running xen 4.2 unstable on ubuntu 12.04. My
screen turns black after starting the hypervisor, the computer
reboots, and leaves no logs. The patch you mentioned shouldn't
change any functionality, so that is probably not the cause. All
the messages from the hypervisor seem typical.
Specs:
Ubuntu 12.04
Kernel: 3.2.0-24-generic
Processor: AMD FX-8150
