[comp.unix.internals] HELP: mapping controller-memory to sys.vir.-address-space

chris@alderan.uucp (Christoph Splittgerber) (09/20/90)

I'm writing a dev.-driver for a controller, with 4-8 MB controller-memory,
for ISC ix386 2.0.2.

I would like to map the controller-memory to sys-virtual-address-space to be
able to use copyin/out to do the data-transfer between controller-memory
and user-address-space.

Because my documentation says, sure, *NOTHING* about this subject, I started
searching through various <sys/includes> to get any hints. I found some
in <sys/immu.h>.

So I did create a pagetable for the controller-memory and linked it into the
page-directory. So far so good, things work well until the system gets short
of memory.

The kernel seems to take the controller memory as public property and put's
in it's own stuff.

??? How to tell the kernel, that the controller-memory is not it's      ???
??? property and no subject of it's  memory-managing, swapping etc.?    ???


Any help or hints are gratefully welcome   ...

Thanks in advance ... Chris