On Tue, May 13, 2025 at 10:59:13PM -0400, Chuck Zmudzinski wrote:
> On 2/13/2025 10:54 AM, César Catrián C. wrote:
> > Hello,
> >
> >
> > I am migrating a Xen NetBSD 10 system to a new hardware and I would like to
> > know if EFI is supported for XEN to pass on the vga console for keeping on
> > loading the kernel.
> >
> > That's because after Xen loading stage at boot, reach the stage of
> > relinquishing VGA console, it goes blank.
> >
> > If there is no solution just I will return to legacy boot.
> >
> >
> > Kind regards
>
> Hi,
>
> I am seeing the same problem, but my system is so new that, unfortunately,
> legacy BIOS boot is not supported at all on the system, it is truly a
> UEFI-only system.
>
> The system has an Intel Raptor Lake i5-14500 CPU, and it is configured to
> boot several systems, such as Fedora, Windows, Alma Linux, and Xen with the
> various Linux distros. Xen works well with various flavors of Linux Dom0 on
> the box. I decided to try out NetBSD 10.1, and I got NetBSD 10.1 with the
> GENERIC amd64 kernel booting on bare metal using UEFI.
>
> So I followed the guide for port netbsd/xen by installing the Xen 4.18 kernel
> and tools from pkgsrc and adding a boot option for Xen to boot.cfg using the
> "load" command for the netbsd-XEN3_DOM0 kernel and the "multiboot" command
> for the Xen kernel.
>
> When I try it I can see that the bootloader loads the Xen kernel and the Xen
> kernel displays some messages on the VGA console. Then I see that the
> bootloader loads the netbsd-XEN3_DOM0 kernel, but before any kernel messages
> are displayed from the netbsd DOM0 kernel the screen goes blank for several
> seconds and then falls back to the default UEFI boot option on the system,
> which happens to be grub2-efi for Fedora. That is normal behavior for the
> UEFI on my box: When the selected non-default boot option fails
> spectacularly, it just gives up and falls back to the default UEFI boot
> option.
>
> So, is netbsd/xen supposed to work with UEFI booting, or are there issues? I
> saw this commit which I thought might have enabled support for booting
> netbsd/xen on UEFI-only systems back in 2019:
I have a server using EFI with Xen and NetBSD dom0. I use the NetBSD boot
loader with:
menu=Boot Xen PV:load /netbsd console=pc root=dk1; multiboot /xen-debug.gz
dom0_mem=8192M console=com1,vga com1=115200,8n1 conring_size=4096k sync_console
If you have a serial console it may be worth a try, to get more messages.
There are also Xen options to help debug this kind of issue (like:
don't give the VGA console to dom0, delay before reboot and so on).
If Xen keeps the VGA console, use console=com0 for NetBSD so that
it sends it boot messages to Xen.
--
Manuel Bouyer <bou...@antioche.eu.org>
NetBSD: 26 ans d'experience feront toujours la difference
--
