direct I/O access

rmgls at wanadoo.fr rmgls at wanadoo.fr
Thu May 31 08:48:00 UTC 2007


On Wed, 30 May 2007 12:39:10 -0400, Mike Meyer <mwm-keyword-freebsdhackers2.e313df at mired.org> wrote,

> Actually, protected mode is just the beginnings of it. I've never done
> much x86 assembly, but going from the '020 to the '030 (or maybe it
> was the '010 to the '020).  I had to start invalidating the hardware
> caches after certain operations. After that, I switched to RISC
> hardware, which were designed assuming that the real people writing
> assembler would be few and far between, and did crazy things like
> rearrange the instruction sequence behind your back and add extra
> instructions. Modern systems do this kind of stuff as well.
 
do you think that it would be better to rewrite the soft in C???
in this case, i have more work to do!
first of all, learning C on the finger tip, before working on my soft.

and i thought that it would be very interesting to learn 
the heart of FreeBSD.


> This really is a kludge, though. You haven't said what you're trying
> to do. If you're trying to keep an old one-of device working, this is
> probably the best way. But if it's a real device that other people
> might be using, then writing a real device driver, or seeing if you
> can make the device work with something like the iic drivers might be
> better.

in fact, they are:
- a direct to disk recorder,
- a sampler.

they are not usable by other people, because they were discontinued.

bests regards

raoul
rmgls at wanadoo.fr



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