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Path: sserve!newshost.anu.edu.au!munnari.oz.au!uunet!mcsun!Germany.EU.net!news From: bs@Germany.EU.net (Bernard Steiner) Newsgroups: comp.os.386bsd.questions Subject: inb(), /dev/mem and mmap(2) Date: 28 Jun 1993 14:24:52 +0200 Organization: EUnet Deutschland GmbH, Dortmund, Germany Lines: 26 Distribution: world Message-ID: <20mnuk$ai4@Germany.EU.net> NNTP-Posting-Host: qwerty.germany.eu.net Folks, Could someone out there enlighten me as to why mmap() fails on character special files such as /dev/mem or /dev/zero, but works OK on regular files ? How does one read a byte from an ISA IOport ? Opening /dev/mem, lseek()ing to 0xa0000+offset and then read()ing a byte does not appear to work. Has anybody implemented the /dev/ioport stuff ? I've seen the stubs in i386/i386/mem.c, but then some macros seem to be missing :-( Is there any other way of doing an inb() and outb() outside the kernel ? Am I just plain stupid, or may it be the case that some vital documentation is missing ? Thanks, Bernard -- ===== ____ ===== EUnet Deutschland GmbH ===== / / / ___ ___ _/_ ===== Emil-Figge-Str. 80 ===== /---- / / / / /___/ / ===== D-W-4600 Dortmund 50 ===== /____ /___/ / / /___ / ===== Germany ======= ======= Vox +49 231 972 2222 ======= Connecting Europe since 1982 ======= Fax +49 231 972 1111