Unaccelerated X on PowerPC machine

["Neil A. Carson" <neil%nc.com@localhost>]

Greetings,

I'm trying to bring up an X server on a PowerPC 603 based machine. It
has a 1280x1024 framebuffer wired to physical 0xC0000000. I point the
rcons/wscons at this in the kernel and it works just fine.

Problem comes when wanting to map this memory from userland, eg the X
server. First of all, the /dev/mem machdep device didn't support mmap.
This was changed, so that mmmmap returned the address divided by the
page size etc as it should.

Now if I mmap 0xc0000000 via /dev/mem, the mmap succeeds and the above
function gets called twice with the first two pages when doing a memset
of the mapped area. But then the machine stiffs. In this case, also
nothing comes out from the screen so it's as though it's going somewhere
else.

Any help or knowledge out there that can explain or help with this one?

        Regards,

        Neil