From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33105) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XILpl-0007DL-P2 for qemu-devel@nongnu.org; Fri, 15 Aug 2014 14:02:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XILpc-00028u-OB for qemu-devel@nongnu.org; Fri, 15 Aug 2014 14:02:37 -0400 Received: from mail-wg0-x233.google.com ([2a00:1450:400c:c00::233]:42978) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XILpc-00028S-Ip for qemu-devel@nongnu.org; Fri, 15 Aug 2014 14:02:28 -0400 Received: by mail-wg0-f51.google.com with SMTP id b13so2599175wgh.34 for ; Fri, 15 Aug 2014 11:02:27 -0700 (PDT) Received: from localhost (109241087153.gdansk.vectranet.pl. [109.241.87.153]) by mx.google.com with ESMTPSA id je3sm8865056wic.11.2014.08.15.11.02.25 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Aug 2014 11:02:26 -0700 (PDT) Date: Fri, 15 Aug 2014 20:02:24 +0200 From: Piotr =?iso-8859-1?Q?Kr=F3l?= Message-ID: <20140815180221.GA25591@echad> References: <20140815100719.GB11560@echad> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Subject: Re: [Qemu-devel] vexpress-a9: coreboot is unable to push any data on stack List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: QEMU Developers On Fri, Aug 15, 2014 at 05:10:04PM +0100, Peter Maydell wrote: > For your stack issues, it looks like your code is trying to > use the area which is the flash as the stack. Since flash > isn't writeable, we ignore the writes and it's not very > useful for stack. It looks like your code is assuming that > the low memory is RAM, not flash -- so how does your > code work on real hardware? Do you try to use the > software controllable remapping to copy from the flash > into RAM before using the stack, or something else? Peter thanks for your reply. I'm not coreboot developer so cannot advocate for their decision. Bootblock that I sent is from build targeted on qemu and developer who initially wrote the code suggest using it with '-kernel' parameter. I would like to fix this code according to correct memory map. Comment in hw/arm/vexpress.c say that, as you wrote below, Versatile Express got two possible memory maps. Can you point me to exact documentation that you use as reference for vexpress implementation ? > > In terms of where we go from here, we have two > choices: > (1) leave address 0 as RAM, not flash; this means > legacy guest binaries that work only on QEMU and > not on real hardware will still work, but the -bios > option won't be of much use. (This is more or less > reverting to the 2.0 situation.) > (2) bring it in to line with vexpress-a15 (which is > effectively how 2.1 shipped), so 0 is always flash > and never RAM. This is consistent but (as you've > found) binaries assuming that 0 is a RAM alias > will stop working. > Assuming option (2) contain strategy for future releases it should be priority. I will try to fix coreboot binary according to this advice. One more time thanks for explanation. Thanks, Piotr Król