Date: Sat, 19 Apr 1997 12:24:48 +0900 From: KATO Takenori <kato@eclogite.eps.nagoya-u.ac.jp> To: rb@gid.co.uk Cc: kato@eclogite.eps.nagoya-u.ac.jp, freebsd-bugs@freefall.freebsd.org Subject: Re: kern/3292: Cyrix 486 performance problem Message-ID: <199704190324.MAA08105@gneiss.eps.nagoya-u.ac.jp> In-Reply-To: Your message of "Fri, 18 Apr 1997 21:36:54 %2B0100" References: <l03020904af7d8b1d935f@[194.32.164.2]>
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I read initcpu.c and compared it to old locore.s, then I found a solution of Cyrix 486 CPU cache. That is just do: Delete cache disable code in init_486dlc(). 1. BIOS on old motherboards may not initialize registers of Cyrix 486. Thus, CPU cache is not enabled at reset time. 2. BIOS on newer motherboards initialize registers of Cyrix 486. Thus, CPU cache is enabled by BIOS. In case 1, usere should recompile with CYRIX_CACHE_WORKS to enable CPU cache, because neither BIOS nor FreeBSD kernel enable it. In case 2, BIOS enables CPU cache and FreeBSD kernel doesn't disable it, even though CYRIX_CACHE_WORKS is not set. ---- KATO Takenori <kato@eclogite.eps.nagoya-u.ac.jp> Dept. Earth Planet. Sci., Nagoya Univ., Nagoya, 464-01, Japan PGP public key: finger kato@eclogite.eps.nagoya-u.ac.jp ------------------- Powered by FreeBSD(98) -------------------
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