Subject: Re: dma and asc driver...
To: None <port-arc@netbsd.org>
From: Toru Nishimura <nisimura@itc.aist-nara.ac.jp>
List: port-arc
Date: 02/24/2001 12:40:59
Mark Abene <phiber@radicalmedia.com> wrote;

> I'm running into some difficulties converting the mipsco asc driver-glue...
> It makes extensive use of the Rambo ASIC's DMA FIFO, but to my knowledge
> the R4030 ASIC has no such FIFO, just the address of a buffer.
> Can anyone lend any guidance on how I should deal with this?  I don't have

Ask soda. He knows who should be blamed about NetBSD/arc.

> any R4030 docs, I'm just working with what I can piece together from header
> files and current code...

RAMBO ASIC is a pretty tiny DMA engine.  It has just 2CH, one for ASC
I/O and another for monochrome output. Yes, R3000 Magnum monochrome
framebuffer is placed in DRAM reserving a segment of memory.  How many
person can enumulate such kind of cost effecificently designed
computers in history?

ARC chipset (R4030 and variations, NEC produced its own run) is
different and complicated animal.  DMA engine uses array of TLB entries
to run Scatter-Gather I/O.

Tohru Nishimura