From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1MIsNR-0001mF-0D for mharc-grub-devel@gnu.org; Mon, 22 Jun 2009 18:52:37 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MIsNP-0001kg-BS for grub-devel@gnu.org; Mon, 22 Jun 2009 18:52:35 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MIsNK-0001f0-31 for grub-devel@gnu.org; Mon, 22 Jun 2009 18:52:34 -0400 Received: from [199.232.76.173] (port=45744 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MIsNJ-0001ex-U4 for grub-devel@gnu.org; Mon, 22 Jun 2009 18:52:29 -0400 Received: from aybabtu.com ([69.60.117.155]:59666) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MIsNJ-0003kB-EP for grub-devel@gnu.org; Mon, 22 Jun 2009 18:52:29 -0400 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1MIrKI-0001h3-3P for grub-devel@gnu.org; Mon, 22 Jun 2009 23:45:18 +0200 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1MIsNG-0003At-RE for grub-devel@gnu.org; Tue, 23 Jun 2009 00:52:26 +0200 Date: Tue, 23 Jun 2009 00:52:26 +0200 From: Robert Millan To: The development of GRUB 2 Message-ID: <20090622225226.GC11998@thorin> References: <20090621181748.GA21152@thorin> <20090621225332.GB2360@thorin> <1245633761.9864.34.camel@mj> <20090622095252.GC8969@thorin> <1245699543.2561.1.camel@mj> <20090622205213.GB7871@thorin> <1245706582.10187.32.camel@mj> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1245706582.10187.32.camel@mj> Organization: free as in freedom X-Message-Flag: Worried about Outlook viruses? Switch to Thunderbird! www.mozilla.com/thunderbird X-Debbugs-No-Ack: true User-Agent: Mutt/1.5.18 (2008-05-17) X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 1) Subject: Re: [PATCH] access gdtdesc on segment 0 unconditionally (Re: [PATCH] i386-qemu port) X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Jun 2009 22:52:35 -0000 On Mon, Jun 22, 2009 at 05:36:22PM -0400, Pavel Roskin wrote: > > What's the problem with removing %cs? It's presence there is bogus. It > > *seems* to indicate gdtdesc is a segment-relative reference, but in fact > > it's not, and it just happens to work because %cs was set to 0. > > I just wanted to make sure we are not doing anything wrong. I have a > feeling that somebody with a good knowledge of assembler tricks could > write the code to use %cs and a 16-bit address, but I don't know how to > do it. We *could* convert the absolute reference generated by binutils into something relative to %cs with a combination of macros (so realmode.S knows what's the %cs value going to be), substract _start, bitshift, etc. But in that case I really think the added complexity makes it unworthy. > Anyway, your code is correct and I have no objections. Please commit. Committed. Feel free to get rid of ADDR32 if you figure out a clean way to do it :-) -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all."