Date: Thu, 31 May 2007 10:47:54 +0200 From: rmgls@wanadoo.fr To: Mike Meyer <mwm-keyword-freebsdhackers2.e313df@mired.org> Cc: freebsd-hackers@freebsd.org Subject: Re: direct I/O access Message-ID: <20070531084755.816A61C0008F@mwinf1907.orange.fr>
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On Wed, 30 May 2007 12:39:10 -0400, Mike Meyer <mwm-keyword-freebsdhackers2.e313df@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@wanadoo.fr
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