From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1MAqpK-0005lk-TX for mharc-grub-devel@gnu.org; Sun, 31 May 2009 15:36:14 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MAqpJ-0005kz-Mr for grub-devel@gnu.org; Sun, 31 May 2009 15:36:13 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MAqpF-0005if-G2 for grub-devel@gnu.org; Sun, 31 May 2009 15:36:13 -0400 Received: from [199.232.76.173] (port=41077 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MAqpF-0005iZ-85 for grub-devel@gnu.org; Sun, 31 May 2009 15:36:09 -0400 Received: from mailout11.t-online.de ([194.25.134.85]:53230) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MAqpE-0004wb-Go for grub-devel@gnu.org; Sun, 31 May 2009 15:36:08 -0400 Received: from fwd04.aul.t-online.de by mailout11.sul.t-online.de with smtp id 1MAqpC-0005F8-00; Sun, 31 May 2009 21:36:06 +0200 Received: from [10.3.2.2] (SmVb9GZdYhLwzRKt1QCSHNO-W210btInreTC+bFbMEDT9jDNqb4hiYgCEfFW-S4gpQ@[217.235.254.37]) by fwd04.aul.t-online.de with esmtp id 1MAqoy-0a4QlM0; Sun, 31 May 2009 21:35:52 +0200 Message-ID: <4A22DC18.7000709@t-online.de> Date: Sun, 31 May 2009 21:35:52 +0200 From: Christian Franke User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.21) Gecko/20090403 SeaMonkey/1.1.16 MIME-Version: 1.0 To: The development of GRUB 2 References: <49E3E0FB.1070907@verizon.net> <1242265918.21129.27.camel@mj> <1242309828.12546.15.camel@mj> <1242325022.6056.7.camel@mj> <1243764078.22342.10.camel@accesodirecto.casa> <1243774114.8044.2.camel@accesodirecto.casa> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-ID: SmVb9GZdYhLwzRKt1QCSHNO-W210btInreTC+bFbMEDT9jDNqb4hiYgCEfFW-S4gpQ X-TOI-MSGID: 87a3fc16-e33f-4b9a-8631-8debd0eb0166 X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 3) Subject: Re: status grub2 port of grub-legasy map command 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: Sun, 31 May 2009 19:36:14 -0000 Vladimir 'phcoder' Serbinenko wrote: >> >> Do not do this. Some BIOS functions (like ah=08h) return data in dl. >> Clients should not expect data in registers to be preserved across >> interrupt calls. I don't know if there is something like a 8086/PC-BIOS >> ABI document that we can find to confirm the non-preservation of dl, but >> the FreeDOS MBR should be fixed then. >> > Thank you for pointing ah=8 function > AFAIK there is no normative reference. The source which was mainly > used for long years is helppc and it states following: > - registers DS, BX, CX and DX are preserved > (http://heim.ifi.uio.no/~stanisls/helppc/int_13.html) > But now this reference is terribly outdated. > SeaBIOS preserves %dl too > T13 EDD provides a probably more up to date documentation of int13. There was no requirement to preserve registers is in EDD (2000) and EDD-2 (2002). It appeared in EDD-3 (2004) and is still in first EDD-4 draft (2009): "The values in all registers that are not explicitly defined in the following sections shall be preserved at the completion of each function call" From Section 8 of: BIOS Enhanced Disk Drive Services - 3 (T13/1572D Revision 3) Fortunately, T13 docs are (unlike T10 and SATA-IO) still publicly available: http://www.t13.org/Documents/MinutesDefault.aspx?DocumentType=4&DocumentStage=2 -- Regards, Christian Franke