[Xorg] Question about X Server Internal

Amir Bukhari ufz6 at rz.uni-karlsruhe.de
Sun Aug 22 00:55:12 PDT 2004

On Sun, 2004-08-22 at 01:56, Adam Jackson wrote:
> Hash: SHA1
> On Saturday 21 August 2004 19:26, Amir Bukhari wrote:
> > On Sun, 2004-08-22 at 01:00, Vladimir Dergachev wrote:
> > > Most accelerated drivers do not access framebuffer directly, just cause
> > > the card to perform the corresponding operation.
> >
> > that is right when XAA is used but I would like to understand cfb code
> > (actually how it access the framebuffer).
> Since you keep mentioning cfb:
> Just don't.  cfb is designed for a much earlier generation of video cards.  
> It's largely dead code, and I really want to mark it deprecated and cut it in 
> the next release.  programs/Xserver/fb has the framebuffer core that almost 
> all of the drivers use these days (excluding sunffb and sunleo, both of which 
> could probably be easily converted to fb).
but I think cfb is used by pixmap operations! or also fb is general for
all depth?

> Anyway.  The driver tells the fb layer where the framebuffer is by calling 
> fbScreenInit during startup.  tdfx_driver.c is typical:
> if (!fbScreenInit(pScreen, pTDFX->FbBase+pTDFX->fbOffset,
>                   pScrn->virtualX, pScrn->virtualY,
>                   pScrn->xDpi, pScrn->yDpi,
>                   pScrn->displayWidth, pScrn->bitsPerPixel))
>     return FALSE;

Yup, that what I search for. the above function call miScreenInit which
then set:
    pScrInitParms->pbits = pbits;
    pScrInitParms->width = width;
    pScreen->devPrivate = (pointer)pScrInitParms;
Now it is clear.

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