Re: epia800 direct vga working

[Nathanael D. Noblet]

Hello,
    So I've got the epia800 working with the original BIOS that was
extracted from the original BIOS. I've been looking over the code that
was submitted, and as well as the difference between register settings
on boot with regular BIOS settings and LinuxBIOS settings. I have been
trying to get DirectFB to work with the epiafb module. It works when I
boot with regular bios, but not the LinuxBIOS version. Here are the
differences between the two.

ORIGINAL
01:00.0 VGA compatible controller: Trident Microsystems CyberBlade/i1
(rev 6a)
00: 23 10 00 85 07 00 b0 02 6a 00 00 03 00 20 00 00
10: 00 00 80 e1 00 00 00 e2 00 00 00 e1 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 23 10 00 85
30: 00 00 00 00 80 00 00 00 00 00 00 00 0b 01 00 00
LINUXBIOS with extracted VGABIOS 
01:00.0 VGA compatible controller: Trident Microsystems CyberBlade/i1
(rev 6a)
00: 23 10 00 85 03 00 b0 02 6a 00 00 03 00 40 00 00
10: 00 00 80 fd 00 00 80 fe 00 00 00 fe 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 23 10 00 85
30: 00 00 00 00 80 00 00 00 00 00 00 00 00 01 00 00

I remember working on a sis530 board that had to set particular
registers, I'm wondering if someone can give me a little tutorial on how
to read these values and turn them into a corresponding register address
so that I can play around with the settings to get it all working. Once
I have that all working like the original bios I guess the direct vga
changes could incorporate the changes and we would not need the VGABIOS
if I am not mistaken? I'd like to help, but need to know how to go about
reading the above in a better way then I know right now...

epia800 direct vga working

[SONE Takeshi]

On Mon, Sep 22, 2003 at 12:34:33PM -0600, Nathanael D. Noblet wrote:
> ORIGINAL
> 01:00.0 VGA compatible controller: Trident Microsystems CyberBlade/i1
> (rev 6a)
> 00: 23 10 00 85 07 00 b0 02 6a 00 00 03 00 20 00 00
> 10: 00 00 80 e1 00 00 00 e2 00 00 00 e1 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 23 10 00 85
> 30: 00 00 00 00 80 00 00 00 00 00 00 00 0b 01 00 00
> LINUXBIOS with extracted VGABIOS 
> 01:00.0 VGA compatible controller: Trident Microsystems CyberBlade/i1
> (rev 6a)
> 00: 23 10 00 85 03 00 b0 02 6a 00 00 03 00 40 00 00
> 10: 00 00 80 fd 00 00 80 fe 00 00 00 fe 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 23 10 00 85
> 30: 00 00 00 00 80 00 00 00 00 00 00 00 00 01 00 00
>
> I remember working on a sis530 board that had to set particular
> registers, I'm wondering if someone can give me a little tutorial on how
> to read these values and turn them into a corresponding register address
> so that I can play around with the settings to get it all working. Once
> I have that all working like the original bios I guess the direct vga
> changes could incorporate the changes and we would not need the VGABIOS
> if I am not mistaken? I'd like to help, but need to know how to go about
> reading the above in a better way then I know right now...

This is PCI configuration space registers. And it is not the
device specific part.
Usually there is no intersting thing here.
You see some differences in resource assignment.
Different BIOSes assign different framebuffer address, etc.

The real fun part is in the extended VGA registers.
And just dumping them all is not a trivial task.
You can see what the standard VGA registers look like at FreeVGA project.
Our VGA device has lots of extended registers over this standard.
Some of them are on "the other side" of standard registers
(something like "reading this standard register 4 times turns 
it into the extended register").