From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57265) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VjTJ7-0001nK-Gm for qemu-devel@nongnu.org; Thu, 21 Nov 2013 07:24:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VjTIy-0001Uw-9j for qemu-devel@nongnu.org; Thu, 21 Nov 2013 07:24:29 -0500 Received: from e06smtp18.uk.ibm.com ([195.75.94.114]:58697) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VjTIy-0001U5-0x for qemu-devel@nongnu.org; Thu, 21 Nov 2013 07:24:20 -0500 Received: from /spool/local by e06smtp18.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Nov 2013 12:24:17 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 1EDF917D8062 for ; Thu, 21 Nov 2013 12:24:01 +0000 (GMT) Received: from d06av06.portsmouth.uk.ibm.com (d06av06.portsmouth.uk.ibm.com [9.149.37.217]) by b06cxnps3075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id rALCO3vd60489916 for ; Thu, 21 Nov 2013 12:24:03 GMT Received: from d06av06.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av06.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id rALCOFAe005518 for ; Thu, 21 Nov 2013 05:24:15 -0700 Date: Thu, 21 Nov 2013 13:24:13 +0100 From: Cornelia Huck Message-ID: <20131121132413.0af9a66d@gondolin> In-Reply-To: <20131121120822.GA23602@redhat.com> References: <20131121120822.GA23602@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-1.7] s390x: fix flat rom load on 32 bit systems List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Alexander Graf , Dominik Dingel , qemu-devel@nongnu.org, Christian Borntraeger , Andreas =?UTF-8?B?RsOkcmJlcg==?= , Richard Henderson On Thu, 21 Nov 2013 14:08:22 +0200 "Michael S. Tsirkin" wrote: > pc-bios/s390-zipl.rom is a flat image so it's expected that > loading it as elf will fail. > It should fall back on loading a flat file, but doesn't > on 32 bit systems, instead it fails printing: > qemu: hardware error: could not load bootloader 's390-zipl.rom' > > The result is boot failure. > > The reason is that a 64 bit unsigned interger which is set > to -1 on error is compared to -1UL which on a 32 bit system > with gcc is a 32 bit unsigned interger. > Since both are unsigned, no sign extension takes place and > comparison evaluates to non-equal. > > There's no reason to do clever tricks: -1 will cause > sign extension to happen correctly automatically. > > Signed-off-by: Michael S. Tsirkin > --- > hw/s390x/ipl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c > index d69adb2..88115e9 100644 > --- a/hw/s390x/ipl.c > +++ b/hw/s390x/ipl.c > @@ -80,7 +80,7 @@ static int s390_ipl_init(SysBusDevice *dev) > > bios_size = load_elf(bios_filename, NULL, NULL, &ipl->start_addr, NULL, > NULL, 1, ELF_MACHINE, 0); > - if (bios_size == -1UL) { > + if (bios_size == -1) { > bios_size = load_image_targphys(bios_filename, ZIPL_IMAGE_START, > 4096); > ipl->start_addr = ZIPL_IMAGE_START; Makes sense, but doesn't the kernel loader just below suffer from just the same problem?