Re: [coreboot] Question on VGA BIOS extraction

[Timothy Pearson]

On 03/30/2015 11:24 AM, Iru Cai wrote:
> Hi,
>
> I'm trying to build Coreboot for ThinkPad X220. I first backup the
> vendor BIOS, then use UEFITool to extract a VBIOS. The romheader program
> detects the ROM's PCI data structure and reports the device id is
> 8086:0106, but the VGA controller's device id is 8086:0126. I extracted
> the video ROM from a running X220 memory and use romheader to test it,
> the result is still 8086:0106. How could this happen?
>
> Iru

Some PCI devices can change their device ID based on a configuration 
register or two (I know the XGI Volari can do this for instance).  It is 
possible that the proprietary BIOS changes the ID for some reason.

Question on VGA BIOS extraction

[Charles Devereaux]

Likewise on thinkpad tablets the name of the digitizer (WACF004) can be
changed by the ACPI DSDT depending on things detected by the BIOS or not.

You may want to check the DSDT

On Mon, Mar 30, 2015 at 12:29 PM, Timothy Pearson <
[e-mail]> wrote:
> On 03/30/2015 11:24 AM, Iru Cai wrote:
> > Hi,
> >
> > I'm trying to build Coreboot for ThinkPad X220. I first backup the
> > vendor BIOS, then use UEFITool to extract a VBIOS. The romheader program
> > detects the ROM's PCI data structure and reports the device id is
> > 8086:0106, but the VGA controller's device id is 8086:0126. I extracted
> > the video ROM from a running X220 memory and use romheader to test it,
> > the result is still 8086:0106. How could this happen?
> >
> > Iru
>
> Some PCI devices can change their device ID based on a configuration
> register or two (I know the XGI Volari can do this for instance).  It is
> possible that the proprietary BIOS changes the ID for some reason.