From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KXe8x-0002d5-5P for qemu-devel@nongnu.org; Mon, 25 Aug 2008 11:38:11 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KXe8r-0002c4-Qq for qemu-devel@nongnu.org; Mon, 25 Aug 2008 11:38:10 -0400 Received: from [199.232.76.173] (port=41029 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KXe8r-0002c1-L9 for qemu-devel@nongnu.org; Mon, 25 Aug 2008 11:38:05 -0400 Received: from mail2.shareable.org ([80.68.89.115]:48731) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1KXe8o-0004r9-MN for qemu-devel@nongnu.org; Mon, 25 Aug 2008 11:38:05 -0400 Received: from jamie by mail2.shareable.org with local (Exim 4.63) (envelope-from ) id 1KXe8W-00079Q-LX for qemu-devel@nongnu.org; Mon, 25 Aug 2008 16:37:44 +0100 Date: Mon, 25 Aug 2008 16:37:44 +0100 From: Jamie Lokier Subject: Re: [Qemu-devel] [PATCH v2 1/6] Use IO port for qemu<->guest BIOS communication. Message-ID: <20080825153744.GA27233@shareable.org> References: <20080825095800.18703.30602.stgit@gleb-debian.qumranet.com.qumranet.com> <20080825095805.18703.63202.stgit@gleb-debian.qumranet.com.qumranet.com> <48B2C0F3.6080101@codemonkey.ws> <20080825144622.GR6192@minantech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080825144622.GR6192@minantech.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Gleb Natapov wrote: > >> +#define BIOS_CFG_IOPORT 0x1234 > >> > > > > I don't think this is a very safe IO port to use. Avi suggested that we > > advertise the IO port that we use as reserved in the ACPI tables. > > > The port number here is just place holder. Any idea of what port we > should use are welcome. ACPI changes should go into bochs tree and not > included in this series. > > > I would have chosen something in the low 400/500 range since Bochs is > > already using this range for debugging. > > > What about 410? Whatever port is chosen, it should be one which common and rare operating systems, recent and ancient, don't "probe" to look for non-PNP ISA devices - unless the protocol requires a magic sequence to be woken (and goes back to sleep following a CPU reset). I quick Google suggests 0x410 is most commonly used by PCMCIA ethernet cards. I've no idea if they are probed using that port. -- Jamie