Xref: utzoo comp.unix.xenix:2541 comp.unix.questions:7786 comp.unix.wizards:9602 Path: utzoo!utgpu!water!watmath!clyde!att!pacbell!ames!mailrus!tut.cis.ohio-state.edu!mandrill!hal!ncoast!allbery From: allbery@ncoast.UUCP (Brandon S. Allbery) Newsgroups: comp.unix.xenix,comp.unix.questions,comp.unix.wizards Subject: Re: What do panic messages mean? Message-ID: <8186@ncoast.UUCP> Date: 26 Jun 88 16:20:45 GMT References: <308@conexch.UUCP> <694@applix.UUCP> <342@conexch.UUCP> <446@sysco> <170@pigs.UUCP> Reply-To: allbery@ncoast.UUCP (Brandon S. Allbery) Followup-To: comp.unix.xenix Organization: Cleveland Public Access UN*X, Cleveland, Oh Lines: 31 As quoted from <170@pigs.UUCP> by haugj@pigs.UUCP (The Beach Bum): +--------------- | In article <446@sysco>, chapman@sco.COM (brian chapman) writes: | ] In article <2375@rpp386.UUCP> jfh@rpp386.UUCP (The Beach Bum) writes: | ] [ now, what i want to know is what is a DNA trap? does this mean the | ] [ machine has been genetically mutated? | ] | ] DNA is Device Not Availible (floating point device, that is) | ] Meaning the kernel is executing *87 instructions. Or trying to. | | its True Meaning(tm), how come i don't see it when i am executing | 80387 instructions? i mean, i use floating point code, but never +--------------- Here's how it works on the 386 boxes I've used: The user-mode trap table is set up so that if an 80387 instruction is seen and the 80387 is not installed, the instruction traps to an emulator. However, there is no such arrangement in the kernel -- so if the kernel tries to run an 80387 instruction and there's no 80387 chip the system panics. This presumably is because the emulator can't easily be made to work in kernel mode; also, the kernel shouldn't need to do floating point unless some kind of special device driver is used -- in which case you probably want the 80387 anyway, for speed. (The system'd get pretty slow if the kernel were spending large amounts of its time in the emulator called from kernel mode.) -- Brandon S. Allbery | "Given its constituency, the only uunet!marque,sun!mandrill}!ncoast!allbery | thing I expect to be "open" about Delphi: ALLBERY MCI Mail: BALLBERY | [the Open Software Foundation] is comp.sources.misc: ncoast!sources-misc | its mouth." --John Gilmore