[Savage40] Savage Frame Buffer

[Tim Roberts]

Nathan Olberding wrote:

>Hmmm... then why is it there?
>  
>

The only devices which really need a custom frame buffer driver are 
devices that cannot be placed into a graphics mode using VESA calls.

The standard frame buffer driver interface offers just enough services 
to make a graphics-mode console work.  That means mode sets, font 
handling, character writes, cursor handling, and window scrolling in 
units of lines and characters.  It offers less than the old VGA INT 10 
interface.  It also returns a pointer to the frame buffer bytes, which 
is what 99.9% of programs use it for, including the XFree86 fbdev driver.

It has no standard ioctls for doing bitblts, rectangle fills, line 
drawing, or bitmap drawing.  Any fancy drawing is done by the 
applications directly, straight into the frame buffer.  A driver is free 
to offer custom ioctls for these, of course, but applications won't know 
about them.

Now, it is possible my knowledge is outdated.  I haven't followed the 
2.6 kernels closely enough.

-- 
- Tim Roberts, timr at probo.com
  Providenza & Boekelheide, Inc.