Messages in this thread |  | | From | "H. Peter Anvin" <> | Subject | Re: missing mxcsr initialization | Date | 27 Oct 2000 00:34:47 -0700 |
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MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Comment-To: Alan Cox <alan@lxorguk.ukuu.org.uk> Disclaimer: Not speaking for Transmeta in any way, shape, or form. Copyright: Copyright 2000 H. Peter Anvin - All Rights Reserved
Followup to: <E13oy7T-00043v-00@the-village.bc.nu> By author: Alan Cox <alan@lxorguk.ukuu.org.uk> In newsgroup: linux.dev.kernel > > > > corrected for include the facts that the XMM feature bit is an Intel specific > > > bit that other vendors may use for other things, so you need to test vendor == > > ^^^ > > Note that they shouldn't do that! I would consider a very bad thing if they > > goes out of sync on those bits. > > CPUID is vendor specific. Every bit in those fields is vendor specific. Every > piece of documentation tells you to check the CPU vendor. Every time we didnt > bother we got burned. > > I keep hearing people saying things like 'bad thing' 'assume standards'. Well > all I can say is cite a vendor issued document which says 'dont bother checking > the vendor'. >
Intel does it because they want every other chip out there to act like a 486.
> > And when you can't find that document, put the checks in so we dont crash on > an Athlon or when using MTRR on a Cyrix III etc >
Chips that don't implement what they claim to implement are buggy and should be treated as such. SPECIAL-CASE THE BUGGY CHIPS, NOT THE PROPERLY FUNCTIONING ONES.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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