--- hw/xfree86/os-support/bsd/ppc_video.c.orig	2012-05-17 19:09:03.000000000 +0200
+++ hw/xfree86/os-support/bsd/ppc_video.c	2013-06-03 13:46:05.165578200 +0200
@@ -135,7 +135,11 @@
 {
 
     if (ioBase != MAP_FAILED) {
+#if defined(__FreeBSD__)
+        munmap(__DEVOLATILE(unsigned char *, ioBase), 0x10000);
+#else
         munmap(__UNVOLATILE(ioBase), 0x10000);
+#endif
         ioBase = MAP_FAILED;
     }
 }
