Re: [Xen-devel] [PATCH v3 13/16 - RFC] x86: add multiboot2 protocol support for EFI platforms

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Fri, Jun 03, 2016 at 03:26:59AM -0600, Jan Beulich wrote:
> >>> On 02.06.16 at 18:12, <daniel.kiper@xxxxxxxxxx> wrote:
> > On Thu, Jun 02, 2016 at 02:34:28AM -0600, Jan Beulich wrote:
> >> >>> On 01.06.16 at 21:03, <daniel.kiper@xxxxxxxxxx> wrote:
> >> > Hence, we are not able to get anything from EFI. Latter
> >> > means that we were booted via older multiboot2 version which shutdown
> >> > boot services.
> >>
> >> Hmm, that's certainly one of the possibilities, yes. I wonder then
> >> whether we wouldn't better do away with all of those output
> >> attempts then.
> > 
> > This is one option. However, IMO, not nice. Maybe we should stay with
> > serial plus VGA on legacy BIOS platforms. Serials looks quite well
> > defined even on EFI platforms. However, if it is not available x86
> > out instruction should not do any harm. Though if we wish to increase
> > chance of reaching interested parties I would send error messages to
> > 0x3f8 and 0x2f8 at once. AFAICT, on many machines usually at least one
> > if not both standard/legacy serial ports are available.
> 
> On many _older_ machines you mean. Any new machines I got
> hold of in the last couple of years didn't have any serial ports
> anymore (some still have them implemented in the LPC, but not
> wired through, but legacy free systems wouldn't have them at all
> anymore).

And there are also new EFI machines that have no VGA whatsoever but
only serial.

> 
> Jan
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel