[Xorg-driver-geode] FreeBSD patch for xf86-video-geode 2.11.12

[Marc Balmer]

Am 14.11.11 02:10, schrieb Martin-Éric Racine:
> 2011/11/14 Gaetan Nadon <memsize at videotron.ca>:
>> On Sun, 2011-11-13 at 23:51 +0200, Martin-Éric Racine wrote:
>>
>> It just occured to me that Marc Balmer once contacted the list with an
>> announce that he was maintaining the OpenBSD port of xf86-video-geode.
>> Let's see if he can participate in this discussion and provide some of
>> the answers. Who knows, he might already have a usable diff to provide
>> us with as a starting point. :)
>>
>>
>> Great.
>>
>> http://www.openbsd.org/i386.html#hardware
>>
>> Geode listed as being supported.
>>
>> http://www.openbsd.org/cgi-bin/cvsweb/xenocara/driver/xf86-video-geode/
>>
>> I could not really see any code changes having been done.
> 
> Try the diff to these two, for starters:
> 
> --- xf86-video-geode/src/Makefile.am
> +++ OpenBSD/xenocara/driver/xf86-video-geode/src/Makefile.am
> 
> --- xf86-video-geode/src/geode_msr.c
> +++ OpenBSD/xenocara/driver/xf86-video-geode/src/geode_msr.c
> 
> There's also some interesting changes to *_driver.c and to lx_exa.c as
> well. A worrisome number of #ifdef, rather than
> autoconf/automake/libtool magic, but it's still a nice start.
> 
>> on OpenBSD/i386 (32 bit) and not 64 bit which would be OpenBSD/amd64 (Intel
>> EMT64 is considered a clone of AMD64). If I see this correctly, the OpenBSD
>> geode driver does not run on 64 bit and therefore would not be of a great
>> help.
> 
> It does help us see how OpenBSD dealt with the lack of V4L2 capability
> and with finding the MSR on their platform, among other things. That's
> a good start for adding BSD support in general.

What I did to make xf86-video-geode usable on OpenBSD was to write an
amdmsr(4) driver which handles the MSR access.  So the driver is
different from the Linux variant in how it accesses MSRs, the rest is
more or less unchanged.

See

http://www.openbsd.org/cgi-bin/man.cgi?query=amdmsr&apropos=0&sektion=0&manpath=OpenBSD+Current&arch=i386&format=html

for the manual page, or

http://www.openbsd.org/cgi-bin/cvsweb/~checkout~/src/sys/arch/i386/i386/amdmsr.c?rev=1.9;content-type=text%2Fplain

for the code.

This way, lseek is not needed to access MSRs.

- Marc

-- 
  \~~~~~.                The NetBSD Foundation
   \~~~~~'               Marc Balmer, Developer / Marketing
  NetBSD
     \                   mbalmer at NetBSD.org   http://www.NetBSD.org/