Date: Wed, 5 May 1999 10:18:23 +0100 (BST) From: Doug Rabson <dfr@nlsystems.com> To: CyberPsychotic <fygrave@tigerteam.net> Cc: freebsd-hackers@freebsd.org, tech@openbsd.org Subject: Re: io ports reading/writing Message-ID: <Pine.BSF.4.05.9905051016150.411-100000@herring.nlsystems.com> In-Reply-To: <Pine.GSO.4.05.9905051359030.632-100000@kyrnet.kg>
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On Wed, 5 May 1999, CyberPsychotic wrote: > ~ > ~ The access control for io ports is controlled by the file-system > ~ permissions on /dev/io. In a standard setup, only root can access this > ~ device. > ~ > > yes. But I was refering to linux scheme, where you can set the port-range, > so the code wouldn't make any unintentional damage. (like if you're working > with cmos you could only permit 0x70/0x71 ports, so even if code goes nuts, > your disks will be safe). This is basically programmer's problem of course, > but the feature is very handy. I don't quite understand the i386 architecture at this level but I seem to remember that this support would require significant changes in the way we handle processes and there might have been some performance implications. I don't think its a big problem in practice. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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