Subject: Need help getting port finished: PCI DMA Problem.
To: None <>
From: Jochen Kunz <>
List: tech-kern
Date: 11/30/2003 22:30:50

I added a new platform to port-ofppc. It supports the Motorola
PowerStack II. This is a nice PReP machine with OpenFirmWare and
depending on model 200 MHz or 300 MHz PPC604e. The port is heading for
single user mode. bus_space(9) works but it seams that bus_dma(9) /
PCI-DMA does not work. I use the same generic PPC bus_dma(9) code from
src/sys/arch/powerpc/powerpc/bus_dma.c as port-prep does, but it does
not work. It just happens nothing when tlp(4) or siop(4) want to do DMA.
I have no idea why and need some fresh ideas on this topic.

If some experienced kernel hacker wants to help: I can provide a remote
developement setup with a NetBSD-prep machine for compiling, netbooting,
serial console and remote power control for the target machine. 

The code I have witten so far is at
This is my complete src/sys/arch/ofppc from a 1.6 source tree. (1.6
because -current is broken on port-ofppc for more then a year now and I
was unable to find the bug(s).)

There is support for the IBM RS/6000 B50 and 43P-150 in this code also.
Currently it lacks the interrupt handling stuff. The B50 / 43P-150 is a
CHRP machine with OpenPIC, so it should be easy to fill this in once the
PCI-DMA works.

Additionally: It should be possible to extend this code to support any
generic OFW-PReP and CHRP machine. Or at least it should be easy adding
speciffic support for more PReP and CHRP machines once the PowerStack II
and B50 are working.