[coreboot] [PATCH] Fix AMD HD 3200 uma graphics problems in Win7

Scott Duplichan scott at notabs.org
Wed Nov 3 05:04:45 CET 2010

-----Original Message-----
From: coreboot-bounces+scott=notabs.org at coreboot.org [mailto:coreboot-bounces+scott=notabs.org at coreboot.org] On Behalf Of Rudolf
Sent: Tuesday, November 02, 2010 05:03 PM
To: coreboot at coreboot.org
Subject: Re: [coreboot] [PATCH] Fix AMD HD 3200 uma graphics problems in Win7

]Hi Scott!
]Thank you very much working on this! I wanted to try out but Igot hang in early 
]init (car stage). Most likely because of this:
]> ===================================================================
]> --- src/southbridge/amd/rs780/rs780_early_setup.c	(revision 6011)
]> +++ src/southbridge/amd/rs780/rs780_early_setup.c	(working copy)
]> @@ -485,7 +485,7 @@
]>   	/*Reg8Ch[10:9] = 0x3 Enables Gfx Debug BAR,
]>   	 * force this BAR as mem type in rs780_gfx.c */
]> -	set_nbcfg_enable_bits_8(nb_dev, 0x8D, (u8)(~0xFF), 0x03);
]> +	set_nbcfg_enable_bits_8(nb_dev, 0x8D, (u8)(~0xFF), 0x06);
]>   }
]>   static void rs780_por_mc_index_init(device_t nb_dev)
]> Index: src/southbridge/amd/rs780/rs780_gfx.c
]Can you please tell what it does?

Hello Rudolf,

Thanks for taking time to test this patch. I assume you tested with
a family 0Fh processor. The mistake I made was testing only with
family 10h, which is how this problem slipped through. Here are the
bit definitions:


The original code was incorrect to set bit 8 because the reference BIOS
does not set it. But that may be insignificant. I believe the real
problem is this. The following sequence is needed needed to reliably
enable the gfx debug bar (bar 6 of bus 1, device 5, function 0):

1) Set bit 9 so that the bar is writable and can be programmed.
2) Allow the resource allocation code assign a range to the debug bar.
3) Set bit 10 to let the debug start decoding its range.

The debug bar is a back door into the pci config space of the RS780.
If it is not setup and working, the ATI graphics driver will not work.

I will re-sumbit the patch with this change. I still have to port some
ACPI changes from mahogany_fam10 to mahogany before I can test Win7
the family 0Fh processor.



More information about the coreboot mailing list