[coreboot] how to prevent legacy resource conflictwith multiple VGA cards

Scott Duplichan scott at notabs.org
Sat Oct 30 07:07:40 CEST 2010

-----Original Message-----
From: coreboot-bounces at coreboot.org [mailto:coreboot-bounces at coreboot.org] On Behalf Of Peter Stuge
Sent: Friday, October 29, 2010 12:41 AM
To: coreboot at coreboot.org
Subject: Re: [coreboot] how to prevent legacy resource conflictwith multiple VGA cards

]Scott Duplichan wrote:
]> "code for WMI Overclock function". I assume that works with some
]> overclocking utility.
]WMI might be Windows Management Interface ?

Yes it is.


Whew, finally solved this problem. 1600 x 1200 32-bit color is now working
with the Win7 in-box ATI driver. The problem is that some important
information is passed from coreboot to the ATI video driver, and some of
it was incorrect. The information is passed by placing it in the last
512 bytes of the frame buffer, so it is easy to look at. The format of
the information is in struct ATOM_INTEGRATED_SYSTEM_INFO_V2.

I should have thought of this when the slow HT link problem resulted in
screen tearing. The driver tries to never let this happen. One of the
items passed to the driver is HT link frequency and width. Hard-coded
values were used for link frequency and width, and frequency was invalid.
Apparently the driver skipped the bandwidth checks because of this.

I believe with this change, Win7 will be able to get through setup
smoothly and most everything will be working. There are several more
patches to submit before mahogany_fam10 will have all of the Win7 changes.


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