Subject: RE: Marvell/evbppc - netbsd-current
To: Matt Thomas <matt@3am-software.com>
From: Fraser Douglas <D.Fraser@flarion.com>
List: port-powerpc
Date: 03/22/2004 10:00:17
Matt, Steve,

I updated from CVS Saturday. The board boots and I get up
to a shell prompt. Thanks for the answers to my questions.

A couple questions about memory layout and virtual memory.

I needed to define options in the config file for
USER_SR, KERNEL_SR and KERNEL2_SR for my build to work.
They default to 12, 13, and 14, which on my target causes
problems in that the BATs for the PCI buses end up at 12 and 13.
The BATs take priority over page tables so the
USER_SR and KERNEL_SR are then inaccessible.

Defining those down to 9, 10, and 11 seems to work, but is
troubling in that there are a couple of spots in the
source code (oea/oea_machdep.c oea/pmap.c) where hard coded
comparisons to 13 and 14 exist. A real head scratcher
for me, maybe not for you.

In particular, Matt, do you know where your PCI space gets
mapped for your card (in oea_batinit() in oea/oea_machdep.c)?

Also, is there any documentation that addresses the BAT and
page table layout and usage for the powerpc ports in general?
(From a NetBSD perspective, of course.....)

Thanks.

Doug Fraser

-----Original Message-----
From: Matt Thomas [mailto:matt@3am-software.com]
Sent: Friday, March 19, 2004 9:15 PM
To: Steve Woodford; Fraser Douglas; port-powerpc@NetBSD.org
Subject: Re: Marvell/evbppc - netbsd-current


At 03:04 PM 3/19/2004, Steve Woodford wrote:
>On Friday 19 March 2004 9:49 pm, Fraser Douglas wrote:
> > It needs (for the ev64260 port) to define macros
> > for:
> > PHYS_TO_BUS_MEM
> > and
> > BUS_MEM_TO_PHYS
>[in <evbppc/bus.h>]
> > which I am afraid will most likely break other
> > evbppc based ports if they are using that bus.h.
> >
> > Can anyone suggest a place to invoke those macros
> > other than in that particular header?
> >
> > Possibly as an option in the config? (though that seems 'brutish')
>
>I can't think of any other way to specify this. I've rattled up an
>evbppc-specific defflag "EVBPPC_BUS_DMA_NEEDS_P2B" which DTRT if
>specified in the kernel config file. If there are no objections, I'll
>commit this.
>
>As I recall, you just need the following definitions for the macros:
>
>#define PHYS_TO_BUS_MEM(t, addr)        (addr)
>#define BUS_MEM_TO_PHYS(t, addr)        (addr)

Don't even need that anymore.  I added gt_dma_phys_to_bus_mem and
gt_dma_bus_mem_to_phys to the gt dma tag.  Which effectively do the
above.


--=20
Matt Thomas                     email: matt@3am-software.com
3am Software Foundry              www: http://3am-software.com/bio/matt/
Cupertino, CA              disclaimer: I avow all knowledge of this =
message.