[coreboot] SeaBIOS and the Geode LX framebuffer
scrocker at ampltd.com
Mon Oct 6 17:24:24 CEST 2008
Jordan Crouse wrote:
> On 06/10/08 15:31 +0100, Stephen Crocker wrote:
>> Carl-Daniel Hailfinger wrote:
>>> On 03.10.2008 12:29, Stephen Crocker wrote:
>>>> Is there a way of getting VGA support with SeaBIOS on the AMD Geode LX
>>>> framebuffer? I have successfully built and tested a BIOS image that
>>>> appears to boot into DOS but the lack of display means that it is of
>>>> little use. Is there a VGA ROM image that I can include?
>>> You'd need a VGA emulation VSA and AFAIK that piece of software is not
>>> available as open source due to an interesting rights situation.
>> How much of this is handled in AMD's binary VSA module? I have been
>> looking through both the AMD and OpenVSA source and it looks as if the
>> lxvg module is supposed to handle VGA SMIs but I cannot find where this
>> is actually done.
> None of it - the VGA is actually a seperate component under difference
> licensing. Thats why you don't see it in the VSA code.
This is quite an important point, as a lot of programs access the I/O
ports and framebuffer directly. A VGA BIOS would be able to handle the
functions provided by INT 10 but in my experience, that would not be
>> Incidentally, I have noticed that the AMD VSA source available from
>> dev.laptop.org cannot be used to build an image with CS5536 support. Is
>> this an old version and, if so, is newer source available?
Please note lines 139-143:
When I attempted to build an image, it defaulted to the CS5530. I did
wonder about fudging the header to use the CS5536 device ID but I also
noticed that the size of my image came to 60,466 bytes whereas the
standard binary image is 57,504 bytes. This would imply a significant
difference in either the source tree, my build environment or both.
I am using the tools supplied with version 3790.1830 of the Windows
Driver Development Kit apart from MASM, which is version 6.14.8444.
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