From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.macqel.be (mail.macqel.be [194.78.208.39]) by ozlabs.org (Postfix) with ESMTP id 966F0DDDEB for ; Tue, 26 Feb 2008 01:47:25 +1100 (EST) Date: Mon, 25 Feb 2008 15:47:22 +0100 From: Philippe De Muyter To: linuxppc-dev@ozlabs.org Subject: E500 linux : are the 64-bit GPRs context-switched ? Message-ID: <20080225144722.GA5011@ingate.macqel> References: <20080221123534.GA17716@ingate.macqel> <20080222095022.GA635@ingate.macqel> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20080222095022.GA635@ingate.macqel> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Dear ppclinux gurus, I have just compiled linux-2.6.24 for a MPC8540 target using a MPC8540 specific gcc. After my first attempt using ARCH=ppc, leading to an infinity of messages : "SPE used in kernel", I recompiled the whole kernel sources using the default ARCH (ARCH=powerpc). I now have a kernel that does not complain about "SPE used in kernel", but user processes still crash ramdomly. Searching around, I learned that the E500 GPR registers are 64-bits wide, and gcc targetted for powerpc-linuxspe uses them sometimes. In the other PPC32 targets, those registers are 32-bits wide. The specific E500 64-bit move instructions are `evstdd' and `evldd'. I searched in the linux kernel sources (2.6.24) but did not find where those GPR registers could be saved in 64-bit mode for context-switch. Is there a patch pending somewhere to preserve the E500 GPR's in 64-bit mode for context-switch ? Philippe