Re: [Linux-fbdev-devel] Supporting various depth

[Matan Ziv-Av <ma...@sv...>]

On Thu, 14 Jun 2001, James Simmons wrote:

> 
> > This won't exactly work - there are some ways to access the vga
> > registers - io (might be remapped from 0x3c0-03df to other address),
> > memory mapped (at any address) or other (nvidia uses other). Also the
> > memory in the linear aperture is organized differently (at least on the
> > nvidia) then the memory at 0xa0000-0xc0000. The solution is probably for
> > the chipset drivers to supply functions (incrtc, outcrtc, etc.)
> 
> So basically I need a vga_ops struct that defines functions to access the
> vga_region. Have any ideas what is needed? How is the linear aperture
> arranged differently?

In vga: 
char[n] is at mem[2n]
attribute[n] is at mem[2n+1]

In nv3, linear aperture:
char[n] is at mem[8n]
attribute[n] is at mem[8n+1]

In other cards it is different from both, but I don't remember the
details.


-- 
Matan Ziv-Av.                         ma...@sv...