Return to BSD News archive
Newsgroups: comp.os.386bsd.bugs Path: sserve!newshost.anu.edu.au!munnari.oz.au!metro!ipso!runxtsa!bde From: bde@runx.oz.au (Bruce Evans) Subject: Re: my bug list Message-ID: <1993Mar31.075706.22898@runx.oz.au> Organization: RUNX Un*x Timeshare. Sydney, Australia. References: <DERAADT.93Mar25200858@newt.fsa.ca> <1993Mar30.003656.2601@fcom.cc.utah.edu> <CGD.93Mar30021341@erewhon.CS.Berkeley.EDU> Date: Wed, 31 Mar 93 07:57:06 GMT Lines: 34 In article <CGD.93Mar30021341@erewhon.CS.Berkeley.EDU> cgd@erewhon.CS.Berkeley.EDU (Chris G. Demetriou) writes: > >i've yet to understand why 386bsd doesn't use the standard >keyboard-controller method of resetting the CPU. 386BSD's method (of causing a triple fault) works slightly better on my machine than the keyboard controller method (programmed by me for Minix). I've since learned more about programming the keyboard controller. It has to be handled carefully. >things like windows (obviously) can drop out of protected mode, >without causing a reset, and i think that it *IS* valid to be able to expect >386bsd to be able to do the same. should be possible, at worst, On 286's there is no way to get out of protected mode except to reset the cpu. The reset must be carefully designed to NOT reset anything else, because resetting would make bimodal programs impractical. >by making the physical and virtual mappings of some part of the kernel >match, being in that part, dropping out of protected mode, and then >immediately using the keyboard controller reset method. On 386's it's "easy" to get out of protected mode though you have to be careful when turning off paging. But this doesn't solve the original problem of resetting the peripherals! As far as I know there is no way to reset them all at once on ISA. EISA is apparently better. >regardless of other points (i think that device shutdown routines >are a good idea), the keyboard controller method is IMO (i make no They won't help when rebooting to 386BSD from another OS. Surely this is more common than controlled rebooting from 386BSD to itself. -- Bruce Evans bde@runx.oz.au