[LinuxBIOS] [PATCH] Fix i82810 to boot!

Joseph Smith joe at smittys.pointclark.net
Tue Jun 19 07:52:04 CEST 2007

Quoting Corey Osgood <corey.osgood at gmail.com>:

> Patch description, long version:
> This patch comments out the code to set up the vga framebuffer to allow
> the system to boot, without this fix the system hangs during elfboot.
> The only line that is absolutely necessary to change is the SMRAM setup,
> however I've commented out all vga setup to make it very obvious to both
> the kernel/payload and anyone looking at the code that vga isn't
> currently working. This setup might also be better handled in
> northbridge.c, if it doesn't need to be done before ram init, yet
> another reason to comment it all. In the future, LinuxBIOS needs to be
> told that the graphics memory area, 1mb or 512kb (at the user or
> developer's option), is reserved for the onchip vga, but I'm not sure if
> it's taken at the top or bottom of the memory, yet. LB may also need to
> set a base address for the AGP aperture and/or be told that range is
> reserved as well, whether this was originally the job of the system bios
> or vga bios is still a mystery. It also corrects the number of entries
> in irq_tables.c, without this fix the kernel would probably complain and
> hang due to unmapped IRQs.

As far as I understand you don't need to define any of the vga  
registers in the northbridge code. Intel's video bios will do all of  
this when initialized, that is if you are using onboard vga. I believe  
it may cause clocking issues if you use both. Some of the registers  
would probibly need to be set if you are using external graphics via  
PCI or AGP. Hope that helps.

Thanks - Joe

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