At Sat, 24 May 2025 13:38:22 +0200, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
Subject: Re: Xen 4.18.5_20250521nb0 not ELF binary (Was: Re: EFI and Xen)
>
> BTW, as you're using a serial console you probably want
> console=com0
> for NetBSD
One never wants NetBSD/Xen dom0 kernel to directly try to use the serial
hardware device as its console.
Xen normally "owns" the serial hardware device after it boots, and it
connects it bidirectionally to the dom0's xencons(4) device [note there
is no such manual page in NetBSD yet].
There's a special escape sequence (three <Ctrl-A> characters, by
default) used by the Xen kernel to switch console control back and forth
between the two kernels after boot. (When connected to Xen one can
press 'h' to see further options, or press <Ctrl-A> three times again to
switch back to the dom0 console.)
For a Xen server that has both a "vga" keyboard and display, as well as
a serial console connection, and where one wants to interact with the
NetBSD console over the serial connection, the correct way to boot is:
menu=Boot Xen:load /netbsd-XEN3_DOM0 console=xencons;multiboot /xen console=com1,vga
Adjust "com1" as necessary, skip the ",vga" if there's no display &
keyboard hardware connected.
The "console=xencons" option for /netbsd-XEN3_DOM0 is actually optional
(or is supposed to be -- I always include it as a form of self-
documentation) since by default XEN3_DOM0 uses the xencons(4) device as
its console.
--
Greg A. Woods <gwoods%acm.org@localhost>
Kelowna, BC +1 250 762-7675 RoboHack <woods%robohack.ca@localhost>
Planix, Inc. <woods%planix.com@localhost> Avoncote Farms <woods%avoncote.ca@localhost>
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