From owner-freebsd-bugs Fri Apr 18 20:25:30 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id UAA23042 for bugs-outgoing; Fri, 18 Apr 1997 20:25:30 -0700 (PDT) Received: from gneiss.eps.nagoya-u.ac.jp (gneiss.eps.nagoya-u.ac.jp [133.6.57.99]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id UAA23034 for ; Fri, 18 Apr 1997 20:25:25 -0700 (PDT) Received: from marble.eps.nagoya-u.ac.jp (localhost [127.0.0.1]) by gneiss.eps.nagoya-u.ac.jp (8.8.5/3.4W4) with ESMTP id MAA08105; Sat, 19 Apr 1997 12:24:48 +0900 (JST) Message-Id: <199704190324.MAA08105@gneiss.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 In-Reply-To: Your message of "Fri, 18 Apr 1997 21:36:54 +0100" References: X-Mailer: Mew version 1.69 on Emacs 19.28.1 / Mule 2.3 X-PGP-Fingerprint: 03 72 85 36 62 46 23 03 52 B1 10 22 44 10 0D 9E Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Sat, 19 Apr 1997 12:24:48 +0900 From: KATO Takenori Sender: owner-bugs@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk 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 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) -------------------