Thread: memory mapped IO: device registers mapped to virtual memory or physical memory?
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Old February 1st 06, 03:55 PM posted to alt.os.development,comp.unix.internals,comp.unix.programmer,alt.comp.hardware
Eli Gottlieb
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Default memory mapped IO: device registers mapped to virtual memory orphysical memory?
Olumide wrote:
Hi -

I know memory mapped IO is about mapping device/controller registers to
memory space in order to reduce the number of processor instructions
(and simplify device driver writing) . My question is: are device
registers mapped to virtual memory or physical memory? I suspect the
former, and I have looked up a number of texts but everyone just seems
to skirt about the issue.

Thanks,

- Olumide

Device registers have a "physical" address that can be mapped into
virtual memory using normal paging techniques, AFAIK.