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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nntp.coast.net!news.kei.com!news.mathworks.com!fu-berlin.de!zrz.TU-Berlin.DE!zib-berlin.de!news.tu-chemnitz.de!irz401!uriah.heep!news From: j@uriah.heep.sax.de (J Wunsch) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: ioperm call on FreeBSD? Date: 30 Dec 1995 21:04:45 GMT Organization: Private BSD site, Dresden Lines: 29 Message-ID: <4c49he$f8v@uriah.heep.sax.de> References: <DKEMoG.C19@midway.uchicago.edu> Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) NNTP-Posting-Host: localhost.heep.sax.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Newsreader: knews 0.9.3 Tim Pierce <twpierce@midway.uchicago.edu> writes: > There is apparently a Linux `ioperm' system call that is used to > set permissions on various I/O ports. I'm afraid I have no idea > what this call does or how it works, but I'm attempting to port > some software that makes use of it, so I'm curious whether FreeBSD > provides any analogous facility, or whether the BSD version of the > code should take any action where Linux would use ioperm. FreeBSD doesn't provide the fine-grain IO permission control Linux has. It is done there by the io permission bits in the extended task state segment. (However, it's usually limited to IO addresses < 0x400 anyway.) The only way on FreeBSD is to open /dev/io, which will grant the process access to any and all IO registers (the permissions of /dev/io should be fairly restrictive, in order to prevent abusing it). Be careful with your application, triple-check that all IO accesses are to the intented ports. (If you can, the better way is writing a device driver that performs the low-level interface part inside the kernel, while the user-level interface is being separated.) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)