Subject: Re: Quadra 840AV scsi DMA
To: John Klos <>
From: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
List: port-mac68k
Date: 04/08/2002 22:02:01
At 11:28 Uhr -0400 8.4.2002, John Klos wrote:
>> Looking around, I can see that we can pretty much copy the bus_dma()
>> routines from the NeXT port.
>Is this really smart? SCSI on NeXT has never been finished, much less
>production quality. Does it have the same SCSI chip? I'd love to see my
>NeXT work one of these days...

Note that Michael spoke about the next68k bus_dma implementation (man 9
bus_dma), not about the dma controller driver code. That will most likely
be very different - the next black hardware was designed to run unix.

>I don't know about Atari, sun3, or hp, but Amiga has some really nice DMA
>SCSI controllers that work wonderfully under NetBSD.

Looking around, I found it strange that

-  many of the m68k ports do not actually implement bus_dma (atari, amiga,
mac68k, hp300, luna68k, news68k). next68k, x68k (looks well-structured),
sun68k (sun[23]) and mvme68k do have bus_dma.

-  the existing implementations of bus_space and bus_dma seem to differ so
little that they should probably be put into m68k.

mac68k's bus_space api is not even up-to-date, btw (see pr16233).


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