Question about IO-fpages

[Christian Stueble]

Am Fre, 22 Okt 1999 schrieben Sie:
> Christian Stueble <stueble at amaunet.cs.uni-dortmund.de> writes:
> 
> > I think Fiasco/L4 uses memory mapped I/O, not separated I/O?
> 
> Memory-mapped I/O (that is, I/O via memory accesses in the virtual
> address space) and I/O via the separate 16-bit I/O address space (with
> in/out instructions; ``port I/O'') are completely separate from each
> other.  It is not possible to map the port address space into the
> virtual memory, and that means it is not possible to replace port I/O
> with memory-mapped I/O.  That's why, the kernel needs to support port
> I/O.
Yes, but I thought an IBM PC uses sepatated I/O, but also maps them into the
memory. (A Linux docu said, that new device drivers use memory mapped
I/O.. ).
Books about PCs describe separated I/O only, so I think this was wrong.

-Chris-

> 
> Michael
> -- 
> hohmuth at innocent.com, hohmuth at inf.tu-dresden.de
> http://home.pages.de/~hohmuth/
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 Christian Stueble............stueble at ls6.cs.uni-dortmund.de
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