Mailing List Archive

> Trying to boot the Xen kernel, all I get is a dark screen. When I remove
> the "quiet" option from Grub's menu point, I see that the last message
> before blanking the screen is "Xen is relinquishing VGA console".

Is this EFI or legacy BIOS/CSM? I will assume legacy, much easier.

Do you see the XEN booting but not the Linux kernel nor the system? You
don't get a system prompt either?

Maybe you just need to force output on VGA, in case it goes to serial
port.

xen.gz argument would be console=vga but you probably don't need that
kernel argument try add console=tty0
but then you should have a prompt showing up anyways, unless systemD
service mgetty now finds out by itself where to spit? (cray things
happen nowadays)

At this stage I think you need to play with booting, then will come XEN
and domU guest tuning. I suggest you try PV and then switch to PVH with
builder = "pvh". By the way you can even run the dom0 as PVH (as it is
a privileged guest) but you absolutely need to define `dom0_mem` for that.

/boot/xen.gz dom0=pvh dom0_mem=1024M,max:8192M loglvl=info noreboot=true

Well, I solved that problem. It was, of course, entirely due to operator
error. The short story is that I use a spare laptop with a dead display
to which I connect an HDMI monitor. However, in the UEFI and BIOS
parameters the laptop's built-in display was configured as the "boot
display" device.

There might have been other factors, since that problem didn't manifest
itself when booting non-Xen'ed Debian, but I won't investigate that and
am happy now after switching to BIOS and selecting HDMI as the boot display.

All other suggestions that Pierre-Philipp made are, for the moment, a
bit over my head, but I have an environment now that enables me to learn.

Thanks!

On 7/26/2020 4:39 PM, Pierre-Philipp Braun wrote:

>> Trying to boot the Xen kernel, all I get is a dark screen. When I
>> remove the "quiet" option from Grub's menu point, I see that the last
>> message before blanking the screen is "Xen is relinquishing VGA
>> console".
>
> Is this EFI or legacy BIOS/CSM?  I will assume legacy, much easier.
>
> Do you see the XEN booting but not the Linux kernel nor the system? 
> You don't get a system prompt either?
>
> Maybe you just need to force output on VGA, in case it goes to serial
> port.
>
> xen.gz argument would be console=vga but you probably don't need that
> kernel argument try add console=tty0
> but then you should have a prompt showing up anyways, unless systemD
> service mgetty now finds out by itself where to spit? (cray things
> happen nowadays)
>
> At this stage I think you need to play with booting, then will come
> XEN and domU guest tuning.  I suggest you try PV and then switch to
> PVH with builder = "pvh".  By the way you can even run the dom0 as PVH
> (as it is a privileged guest) but you absolutely need to define
> `dom0_mem` for that.
>
> /boot/xen.gz dom0=pvh dom0_mem=1024M,max:8192M loglvl=info noreboot=true
>

On 2020-07-26 10:55 p.m., Bernd Bausch wrote:
> Well, I solved that problem. It was, of course, entirely due to
> operator error. The short story is that I use a spare laptop with a
> dead display to which I connect an HDMI monitor. However, in the UEFI
> and BIOS parameters the laptop's built-in display was configured as
> the "boot display" device.
>
> There might have been other factors, since that problem didn't
> manifest itself when booting non-Xen'ed Debian, but I won't
> investigate that and am happy now after switching to BIOS and
> selecting HDMI as the boot display.
>
> All other suggestions that Pierre-Philipp made are, for the moment, a
> bit over my head, but I have an environment now that enables me to learn.
>
> Thanks!
>
> On 7/26/2020 4:39 PM, Pierre-Philipp Braun wrote:
>
>>> Trying to boot the Xen kernel, all I get is a dark screen. When I
>>> remove the "quiet" option from Grub's menu point, I see that the
>>> last message before blanking the screen is "Xen is relinquishing VGA
>>> console".
>>
>> Is this EFI or legacy BIOS/CSM?  I will assume legacy, much easier.
>>
>> Do you see the XEN booting but not the Linux kernel nor the system? 
>> You don't get a system prompt either?
>>
>> Maybe you just need to force output on VGA, in case it goes to serial
>> port.
>>
>> xen.gz argument would be console=vga but you probably don't need that
>> kernel argument try add console=tty0
>> but then you should have a prompt showing up anyways, unless systemD
>> service mgetty now finds out by itself where to spit? (cray things
>> happen nowadays)
>>
>> At this stage I think you need to play with booting, then will come
>> XEN and domU guest tuning.  I suggest you try PV and then switch to
>> PVH with builder = "pvh".  By the way you can even run the dom0 as
>> PVH (as it is a privileged guest) but you absolutely need to define
>> `dom0_mem` for that.
>>
>> /boot/xen.gz dom0=pvh dom0_mem=1024M,max:8192M loglvl=info noreboot=true
>>
Glad to hear you figured it out.

I did some editing of the Beginners Guide a few years ago. I'd be
grateful to hear about any other difficulties you ran into getting it
running or places where the text could be clearer.

David