Subject: Re: MPC8245 DMA controller driver
To: Chanyoun Park <>
From: Allen Briggs <>
List: tech-kern
Date: 10/19/2005 07:18:50
On Wed, Oct 19, 2005 at 05:00:56PM +0900, Chanyoun Park wrote:
> 1) Is the DMA controller implemented in NetBSD 1.6.2? or any other
> version of NetBSD?

I don't think so for that chip.  But do you mean the DMA controller
on the chip, or DMA for PCI devices?  PCI devices usually have their
own DMA controllers that do bus mastering themselves.  The bus_dma(9)
routines are there to support those (and for devices on busses other
than PCI).

> 3) If it is not, then what should I do to use the DMA controller in
> NetBSD 1.6.2?

If you're looking at the on-board DMA controller, I think you're
sort of on your own for 1.6.2.  In NetBSD 2.0, the dmover(9)
interface appeared.  This provides a machine-independent interface
to DMA hardware.  It requires that you (or someone) implement the
"backend" for your specific hardware.  I don't think anyone has
written a backend for the Freescale/Motorola 8245 (is that the same
controller as the MPC8240, MPC107, etc?).

Does that help?


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