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Article #2396HELP: kernel routines for device driver
From: Graham Hausler
Date: Fri, 20 Nov 1992 08:45
Date: Fri, 20 Nov 1992 08:45
26 lines
1594 bytes
1594 bytes
I have reached a brick wall in attempting to implement my first device driver on a Motorola MVME187 running System V/88 R32V3. I need some/all of the following details clarified .... 1. Can I access physical memory (not in IO space) directly from a device driver, assumming I have removed this memory from usage by unix? I want the physical memory at a fixed address, and hence cannot allocate in virtual address space and then derive the physical address (assuming I can even manage that !!) 2. If I cannot access directly, what supplied routines within the kernel are good candidates for trying to perform the accesses ie 'fake DMA' type transfers and the like ... If you suggest routines like undisjointio(), I would appreciate some details as my documentation does not describe it! If any of the above solutions seem long-winded and horribly indirect, maybe someone can explain how unix performs it's shared memory operations when you can directly attach/access the same physical memory??? Please email any responses, I will forward relevant information to anyone that requests it .... Thanks Graham Hausler -- Internet: hausler@aldetec.oz.au --> GEMCO, Perth, Australia.
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Path: arc1-ca.pugleaf.net!sparky!uunet!usc!rpi!batcomputer!munnari.oz.au!uniwa!aldetec!hausler From: hausler@aldetec.oz.au (Graham Hausler) Newsgroups: comp.unix.internals,comp.unix.programmer Subject: HELP: kernel routines for device driver Message-ID: <522@aldetec.oz.au> Date: 20 Nov 92 08:45:31 GMT Organization: Aldetec Pty Ltd, Perth West Australia Lines: 27