If someone likes to know: I got XFree86 up and running on this iBook and
it took me to take steps beyond what was to posted to this list earlier.
Though these patches are a bit "rude", but they work for now. Don't know
why I require the 2nd change, maybe something missing in my kernel
config, so I can't access to the MMIO of my graphics adapter using the
fd of the wscons itself?

file: xsrc/xfree/xc/programs/Xserver/hw/xfree86/drivers/ati/radeon.h
line: 71
- #define RADEON_MMIOSIZE 0x80000
+ #define RADEON_MMIOSIZE 0x20000

file:
xsrc/xfree/xc/programs/Xserver/hw/xfree86/os-support/bsd/bsd_video.c
line: 630
- int fd = xf86info.screenFd;
+ int fd = open ("/dev/mem", 2);
line: 639
- return base;
+ close (fd);
+ return base;

-- 
Gruss
  Matthias Kretschmer