Quiescing Nubus DMA?

[Hauke Fath <hauke%Espresso.Rhein-Neckar.DE@localhost>]

All,

given the size of the audience, this question should probably go to
tech-kern, and may eventually. Still...

I have (once again) taken up toying with an FWB Jackhammer Nubus SCSI card,
which features a 53c720 controller. It looks like the 53c720 is active even
after the kernel has taken over, punching random holes into memory early
during the boot and way before Nubus is probed. I've looked at the sn(4)
DMA code, but we have other means of learning early up that the
corresponding DMA hardware is present, and silence it, so that does not
really help.

What is the general NetBSD take on this, short of hacking the booter into
shutting down the 53c720 DMA before handing control to the kernel?
Unfortunately, mac68k hardware does not go through a full reset sequence
before booting into NetBSD.

Puzzled,
        hauke

--
"It's never straight up and down"     (DEVO)