Hi,
James is right, I have been tackling with this for ages. I have an
i810 driver (http://i810fb.sourceforge.net) that's been "ready" for
some time now, but never submitted it for kernel inclusion precisely
because of this issue.
The i810/1815 has no video memory of it's own, except for memory stolen
from system RAM (512 to 1024K). Unfortunately, entire memory is
accessible only through bank switching and is primarily used for legacy
VGA. Linear memory is availably only through GART mappings.
I've seen/done/been thinking of the following approaches:
1. Do custom GART mappings only - abandoned
2. Fake a linear framebuffer by bank switching the 'stolen memory' -
this idea is by Matt Sottek, but he might have some problems with this
3. Force loading of agpgart before the console/framebuffer - my current
approach in 2.4
4. Do custom GART mappings, wait for agpgart to be available, then use
kernel GART mapping routines - my current approach for 2.5
5. Create a fake framebuffer from System RAM, wait for agpgart to be
loaded, then map the GART - been toying with this idea
The easiest solution for me is to initialize the agpgart ahead of the
framebuffer. Since I'm not a kernel hacker, I don't really get a clear
picture of the issues involved and I'll be grateful for any input.
Thanks
Tony
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