Re: Black screen with GMA500 driver on Atom E680 (invalid VBT signature)

[Andreas Werner <wernerandy@gmx.de>]

On Thu, Nov 14, 2013 at 08:57:58PM +0000, One Thousand Gnomes wrote:
> > but if you checkout the PCI table in the driver, there is the device
> > and vendor ID mentioned, that means for me that the driver supports
> > the Graphic core in E680.
> > And after loading the driver, it will parse for $VBT.
> > I just find a comment in the PCI table with "E620" but
> > the device and vendor id is the same for E680.
> > 
> > What do you mean with "Moorestown style" ?
> 
> There are essentially two styles of configuration table used with PVR
> graphics. One is basically the same as that used on 'real' Intel graphics
> the other first introduced with one of the SoC devices is a firmware
> table in a completely different format.
> 
> The netbook and PC oriented devices use the VBT, the tablet SoC
> devices and embedded ones seem to vary and have a VBT/GCT in different
> form that is found via config 0xFC on the chipset - see mid_bios.c
> 
> Alan
Hi,
if i dump the memory on 0xFC of the config space, there is just some from the
BIOS vendor with a BIOS Version, but nothing like $GCT.

In the Datasheet the 0xFC is described as "storage" does it mean there should
be the settings for the Graphic like VBT?
I did not find more information abaout GCT and how to implement it.


The board uses sdvo->vga for the output, the second board
uses sdvo->DVI and LVDS but there is always a  black screen on each
output interface. So i think there is wether a VBT not a GCT.

Regards 
andy