The correct response would have been, "Only if you start reading the
whole message."
I apologize. I screwed up - I thought you were only trying to access
the I/O ports. Again, sorry.
> I had two fundamental problems with my approach.
>
> 1) a pointer into VIRTUAL MEMORY will never reach ioports.
It will if you map /dev/ioports. I don't really recommend it though,
as it is kinda slow.
> 2) gcc -O is imperative for outb/inb/outw/...etc to compile.
> initially I gave up on these because I couldn't compile
> without getting bad symbol references
Ya, this is a hiden gottcha.
> Exactly. Except iopl(3), in addition to raising the bitmap to take 8k,
> sets it to allow access to any ioport, thus ioperm is not necessary
> when iopl is called. Or so that is the current behavior. I know not
> if it is correct behavior.
Makes sense to me.
-- Andrew E. Mileski mailto:aem@ott.hookup.net Linux Plug-and-Play Kernel Project http://www.redhat.com/linux-info/pnp/ XFree86 Matrox Team http://www.bf.rmit.edu.au/~ajv/xf86-matrox.html