Date: Fri, 7 Nov 1997 01:44:44 -0800 From: Jonathan Mini <mini@d198-232.uoregon.edu> To: Mike Smith <mike@smith.net.au> Cc: hackers@FreeBSD.ORG Subject: Re: x86 gods; advice? Suggestions? Message-ID: <19971107014444.46046@micron.mini.net> In-Reply-To: <199711070933.UAA00302@word.smith.net.au>; from Mike Smith on Fri, Nov 07, 1997 at 08:03:05PM %2B1030 References: <19971107000430.02841@micron.mini.net> <199711070933.UAA00302@word.smith.net.au>
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Mike Smith <mike@smith.net.au> stands accused of saying: > > What privelege level is this running at? > > It has to run with DPL = 0. Why? > > Why not just execute an illegal instruction and catch it? > > Because this is in the kernel context, and I've no way of knowing how > to say "just for now I want illegal instructions to come here". Although it seems less elegant, it seems to me that it really is the best solution to create threads for kernel-started processes for things like vm86/16-bit-protected-mode BIOS calls. What we need is an elegant way to fork a process to do something for the kernel. (an interesting concept when you think about it. Kind of a reverse syscall) > > (in my vm86 code, I use hlt for this all the time) > > Yes, that's what JL uses to kill execution after his interrupt thunk > (which is working wonderfully BTW). > > mike -- Jonathan Mini Ingenious Productions Software Development P.O. Box 5693, Eugene, Or. 97405 "A child of five could understand this! Quick -- Fetch me a child of five."
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