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Newsgroups: comp.os.386bsd.development Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!howland.reston.ans.net!europa.eng.gtefsd.com!uunet!mcsun!sun4nl!relay.philips.nl!cnplss5.cnps.philips.nl!bashful.isp.cft.philips.nl!rooij From: rooij@bashful.isp.cft.philips.nl (Guido van Rooij) Subject: Re: V86 mode & the BIOS (was Need advice: Which OS to port to?) Message-ID: <1993Aug18.071218.5135@cnplss5.cnps.philips.nl> Sender: news@cnplss5.cnps.philips.nl (USENET News System) Organization: Philips Communications & Processing Services, Eindhoven References: <3390@vall.dsv.su.se> <CB11pL.D12@imag.fr> <107181@hydra.gatech.EDU> <1993Aug4.073826.24956@fcom.cc.utah.edu> <107725@hydra.gatech.EDU> <245jrfINNrc0@bonnie.tcd-dresden.de> <108457@hydra.gatech.EDU> <1993Aug12.110032.16307@cnplss5.cnps.philips.nl> <109150@hydra.gatech.EDU> Date: Wed, 18 Aug 1993 07:12:18 GMT Lines: 15 gt8134b@prism.gatech.EDU (Howlin' Bob) writes: >This is unfortunate. If the *BSD developers deem it useful to allow tasks >to keep individual I/O permission bitmaps, perhaps they would consider adding >a per-task flag and pointer; the first access to an ioperm()-like function >would set up an I/O bitmap and set the flag to true; the software task >switcher would only have to copy the bitmap when switching to a task >with the I/O flag set; switching from a task with the I/O flag set to >one without it would merely require setting the I/O bitmap length to 0. Maybe it is faster to reserve this space always and always do the memcpy. Especially when you only control the first 3ff ports this way, and the rest via the IOPL -Guido