Re: X server in dom0: Bad VBT signature

[rudolf <netbsd%eq.cz@localhost>]

Cherry G. Mathew wrote:
> On 2 September 2012 13:14, rudolf<netbsd%eq.cz@localhost>  wrote:
> > I've tried the patch with following results:
> >    - starting X with vesa driver results in a graphical garbage displayed on
> > the screen, where the X should be visible, it is possible to switch between
> > this screen and text wscons screens
> >    - starting X with intel driver results in "Fatal server error: Unknown GTT
> > size value: 4e3eff2f" (the number seems to be always the same), last related
> > lines from Xorg.0.log:
[...]
> > I've also hit another problem, I don't know, if it is related:
> >    - dom0 with 512 MB RAM: switching between wscons text screen with 25 lines
> > and text screen with 50 lines causes immediate panic (display is garbled;
> > "blind" sync, ... savecore -n -Z ...: no core dump)
> >    - dom0 with 6 GB RAM: switching is ok
>
> Thanks for testing - you probably dtrt, but just checking - was this
> patch on top of a clean -current with no extra patches ?

Yes. But now I've made some more experiments with the setup and found 
the following:

These are my only lines with "status = on" from /etc/ttys:
console "/usr/libexec/getty Pc" vt100  on secure
ttyE1   "/usr/libexec/getty Pc" wsvt25 on secure

I've made tests with following two variants of "screen" lines in 
/etc/wscons.conf:
1)
screen  1       80x25   vt100
screen  2       80x50   vt100
screen  3       80x25   vt100
screen  4       -       -
2)
screen  1       80x25   vt100
screen  2       80x25   vt100
screen  3       80x25   vt100
screen  4       -       -

Variant 1) causes panic upon switching to the screen with 50 lines not 
only under the patched kernel with 512 MB RAM - it panics with an 
unpatched XEN3_DOM0 kernel (daily 201209010830Z) with 512 MB RAM as well.

Variant 1) also causes different kind of problems (panics or garbage on 
display) starting the X server with the patched kernel (tested under 512 
MB and 6 GB RAM, vesa and intel drivers, all wrong).

When I changed the wscons.conf to variant 2), it was possible to start 
and use the X server under the patched kernel (tested under 512 MB and 6 
GB RAM, vesa and intel drivers, all ok).

I hope I haven't interchanged any results, if you have any doubts, I can 
test any of these setups again.

r.