Re: Migrating ports from XFree86 to Xorg (Was: Changing default X11_TYPE from native to modular for some platforms)

[Frank Wille <frank%phoenix.owl.de@localhost>]

On Wed, 21 Sep 2011 10:35:42 -0400
Michael <macallan1888%gmail.com@localhost> wrote:

> Most drivers do not depend on wsdisplay, and those which do are
> things like crime ( which can't be probed through some sort of bus so
> it uses /dev/ttyE0 to talk to the kernel driver ) and wsfb
> ( obviously )

Ok. So we could theoretically port an Xorg driver before wsdisplay
exists? Nice.


> The mouse and keyboard drivers pretty much require
> wscons though.

Which means wskbd and wsmouse is required?

Those drivers already exist for amiga, but as I understand wskbd only
works with a wsdisplay. When there is an ite driver running, then the
keyboard events are fed to it instead (according to amiga/dev/kbd.c).

So the ite must be closed when starting an Xorg driver to make wskbd
connect it...? Sounds complicated.


> If you have a mappable framebuffer then attaching a wsdisplay on top
> of it is pretty much trivial.

Great! That's what I hoped.
So I still think we should do the new wsdisplays first, as it would also
solve the confusion mentioned above.

I'm only unsure about the screen modes. Currently we are loading a screen
mode definitions file using grfconfig(8) into the grf driver, which
contains the exact timings and dimensions for the modes.

Maybe we should just include some fixed VESA modes in wsdisplay instead?


> The only problem I see is with the
> Amiga's built-in graphics hardware which doesn't give us packed
> pixels as far as I know.

True. But IMHO this is not extremely important to support. I doubt that
many people want to run X in flickering 640x400 interlaced at 30Hz.


> > A typical NetBSD/amiga user will have a special Amiga graphics card
> > (usually CirrusLogic or S3 based) in a Zorro3 slot.
> 
> Xorg has drivers for both, adding support for Z3 on top of PCI would
> not be that hard. Or one could do what I did with the ag10e driver -
> take the chip-specific part and stick it in a new driver that knows
> about the new bus, maps stuff etc. so the rest of the driver can
> work.

Sounds good. I only wonder why this hadn't been done in the past. The
X drivers for these chips certainly existed before the Amiga drivers
were written.


> I suspect the Cirrus and S3 chips mentioned above will be VLB
> or PCI variants with some Z3-specific glue logic.

Exactly.

-- 
Frank Wille