From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NCPNG-0004zF-1Q for qemu-devel@nongnu.org; Sun, 22 Nov 2009 22:13:58 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NCPNB-0004yf-A9 for qemu-devel@nongnu.org; Sun, 22 Nov 2009 22:13:57 -0500 Received: from [199.232.76.173] (port=52795 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NCPNB-0004yc-5f for qemu-devel@nongnu.org; Sun, 22 Nov 2009 22:13:53 -0500 Received: from mga07.intel.com ([143.182.124.22]:37419 helo=azsmga101.ch.intel.com) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NCPNA-0005d1-T0 for qemu-devel@nongnu.org; Sun, 22 Nov 2009 22:13:53 -0500 Message-ID: <4B09FDEC.9090102@linux.intel.com> Date: Sun, 22 Nov 2009 19:13:48 -0800 From: "H. Peter Anvin" MIME-Version: 1.0 References: <1258752795-15434-1-git-send-email-hpa@linux.intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] debugcon: support for debugging consoles (e.g.Bochs port 0xe9) List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Sebastian Herbszt Cc: qemu-devel@nongnu.org Sebastian Herbszt wrote: > H. Peter Anvin wrote: >> Add generic support for debugging consoles (simple I/O ports which >> when written to cause debugging output to be written to a target.) >> The current implementation matches Bochs' port 0xe9, allowing the same >> debugging code to be used for both Bochs and Qemu. > > Your implementation seems to miss the read part, unless you don't want > to be > compatible with Bochs. user.dbk says: > "Reading from port 0xE9 will will return 0xe9 to let you know if the > feature is available." > I had actually missed that part... it seems somewhat pointless to me, but if that's the way Bochs does it it probably would indeed be better to be compatible. -hpa