Re: Xen boot strangeness (Was: Re: [SOLVED] Re: Xen 4.18.5_20250521nb0 not ELF binary (Was: Re: EFI and Xen))

[Christoph Badura <bad%bsd.de@localhost>]

On Thu, May 29, 2025 at 09:23:46PM +0200, Manuel Bouyer wrote:
> On Thu, May 29, 2025 at 03:01:50PM -0400, Chuck Zmudzinski wrote:
> > The strange part is that it is necessary to pass -c to the DOM0 in boot.cfg to
> > actually disable com* and the bootloader does not execute the userconf=disable com*
> > command that is present in boot.cfg when booting NetBSD/xen DOM0. The userconf=com*
> > setting works for the boot without Xen, but with Xen the bootloader ignores that
> > setting in boot.cfg.
> 
> This is because the userconf command from the boot loader doens't make it
> to the dom0 kernel.
> Remember that when booting Xen; Xen is the kernel and XEN3_DOM0 a module.
> I don't know if multiboot allows passing extended informations to a module.

Every module can be passed a string.  That's even in the 0.6.96
specification.  Took me 5 minutes to look that up.

And even if standard multiboot doesn't allow it.  It is our bootloader code
so we can extend it every way we like.

--chris