X11 CURRENT and non-altivec based macs

[Andreas Tobler]

Hi all,

I discovered a nasty issue which hits all non-altivec based ppc systems, 
mostly G3, there are some 7400 w/o altivec, which want to use X11.

When you upgraded to -CURRENT and latest Xorg stuff including 
pixman-0.15.2 you'll hit a coredump when starting X with a recent/decent wm.

Analyzing the coredump of Xorg led me to this:

#0  0x21b9e494 in pixman_have_vmx () from 
/usr/local/lib/libpixman-1.so.9 Cannot find new threads: generic error

A closer look into the build of pixman showed me that it was built with 
altivec support. No go on my G3.

I helped myself with the below patch in the ports Makefile. But I do not 
know if the other ppc users 'have' real working Altivec support. We have 
Altivec support since a few moons in the kernel. Thanks Nathan!
I know we build the kernel w/o Altivec. How do we want to build user 
applications/packages? Also w/o altivec or with?

We can either adjust the ports Makefile or try to fixup the pixman 
sources. They are currently 'fixed' for apple and linux only. Fixed in 
terms of runtime detection of Altivec capability. (see pixman/pixman-pict.c)

Do we have already a sysctl telling us we have altivec, I do not see 
such a sysctl?

Suggestions?
In case of disabling vmx on all ppc based systems, who do I need to 
ping, x11 at freebsd.org?

Thanks,

Andreas

imacb# diff -u /usr/ports/x11/pixman/Makefile.orig 
/usr/ports/x11/pixman/Makefile
--- /usr/ports/x11/pixman/Makefile.orig	2009-04-18 22:25:40.000000000 +0200
+++ /usr/ports/x11/pixman/Makefile	2009-04-18 22:25:56.000000000 +0200
@@ -17,8 +17,14 @@
  USE_PERL5_BUILD=yes
  USE_GNOME=	ltverhack:9

+.include <bsd.port.pre.mk>
+
+.if ${ARCH} == "powerpc"
+CONFIGURE_ARGS+= --disable-vmx
+.endif
+
  post-patch:
  	@${REINPLACE_CMD} -e 's|gtk+-2\.0|disable-gtk|g' \
  		-e 's|-msse||' ${WRKSRC}/configure

-.include <bsd.port.mk>
+.include <bsd.port.post.mk>