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

[Michael <macallan1888%gmail.com@localhost>]

Hello,

On Wed, 21 Sep 2011 11:52:22 +0200
Frank Wille <frank%phoenix.owl.de@localhost> wrote:

> BTW, does a normal Xorg driver require a wscons/wsdisplay, or can it be
> started completely independant of the console (ite, wscons, or whatever) ?

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

> I would prefer to have wsdisplay drivers for all seven Amiga graphics
> cards first. This is even something I would be capable doing, or at least
> helping with, in constrast to an Xorg driver...

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

> 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.
( Fujitsu's AG-10e is a monstrosity that hides a bunch of PCI graphics chips 
behind a custom made and completely undocumented SBus-PCI bridge. Luckily the 
firmware tells us where to find the various memory and register ranges 
belonging to the individual chips so getting it to work wasn't that hard - just 
couldn't treat them as PCI. )
I suspect the Cirrus and S3 chips mentioned above will be VLB or PCI variants 
with some Z3-specific glue logic.

have fun
Michael