From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.lixom.net (lixom.net [66.141.50.11]) by ozlabs.org (Postfix) with ESMTP id 4FFD3DDE28 for ; Tue, 30 Sep 2008 04:00:47 +1000 (EST) Date: Mon, 29 Sep 2008 13:04:55 -0500 From: Olof Johansson To: Tirumala Reddy Marri Subject: Re: Disabling L1 D-cache and side effects Message-ID: <20080929180455.GA19014@lixom.net> References: <9323BAFB78DE7C4183466AD03F73EA424D46071D@SDCEXCHANGE01.ad.amcc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Cc: linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Sep 29, 2008 at 10:05:41AM -0700, Tirumala Reddy Marri wrote: > > Hi, > I had to bring up a PPC based SOC with L1 dcache disabled. I did that > and tried to boot Linux using RAMDISK/NFS mount. In RAMDISK I see the > file system errors. In case of NFS mount I see error saying failed to > load ld.so library. > > Could you guys please share thoughts what are the different side > effects might be causing this. There are a number of things you have to be careful about when you disable caches. Depending on your implementation, you likely can't use lwarx/stwcx, cache ops will not work, etc. Also, are you 100% sure that this is caused only by disabling L1D, and not by any other problems with your silicon? If you're doing early bringup of you'll have a whole lot of debug work in front of you, and this mailing list is probably not the best place to bring your homework. -Olof