Re: dma at ebus

[Eduardo Horvath <eeh%NetBSD.org@localhost>]

On Mon, 31 May 2010, Chris Ross wrote:

>  So, in working on my X1 some more, I notice that the GENERIC kernel has a
> "dma* at sbus?", presumedly solely for the "esp* at dma?".  And, my Sun Netra
> X1 has a dma at ebus that is "not configured".
> 
>  Is the dma reported by the OBP not nearly the same as the "dma* at sbus?"?
> Or, it is just that there's no need for it, so no one adapted the driver to
> attach it?

Could be.

On some machines the "ebus" is actually the same Happy Meal chip that's 
attached to SBUS to provide SCSI and 10MB ethernet.  In some cases some of 
the functions are not used.

On other machines it's a standard PC "soutbridge" chip.  In this case the 
DMA is probably the ISA DMA.

Unless there's something directly wired to it, the DMA feature is probably 
unused.

Eduardo