This message generated a parse failure. Raw output follows here. Please use 'back' to navigate. From devnull@lkml.org Fri Apr 26 16:39:35 2024 Received: from spaans.ds9a.nl (adsl-xs4all.ds9a.nl [213.84.159.51]) by kylie.puddingonline.com (8.11.6/8.11.6) with SMTP id g8IKw5X20314 for ; Wed, 18 Sep 2002 22:58:06 +0200 Received: (qmail 30688 invoked from network); 18 Sep 2002 06:32:42 -0000 Received: from unknown (HELO spaans.ds9a.nl) (3ffe:8280:10:360:202:44ff:fe2a:a1dd) by mayo.ipv6.ds9a.nl with SMTP; 18 Sep 2002 06:32:42 -0000 Received: (qmail 29178 invoked by uid 1000); 17 Sep 2002 20:00:16 -0000 Received: (maildatabase); juh Received: (qmail 24004 invoked by alias); 30 Jan 2001 18:43:53 -0000 Received: (qmail 24001 invoked from network); 30 Jan 2001 18:43:52 -0000 Received: from vger.kernel.org (199.183.24.194) by spaans.ds9a.nl with SMTP; 30 Jan 2001 18:43:52 -0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 30 Jan 2001 13:41:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 30 Jan 2001 13:41:23 -0500 Received: from chaos.analogic.com ([204.178.40.224]:1408 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id ; Tue, 30 Jan 2001 13:41:10 -0500 Received: (from root@localhost) by chaos.analogic.com (8.11.0.Beta3(chaos.analogic.com)/8.11.0.Beta3) id f0UIaQ300167; Tue, 30 Jan 2001 13:36:26 -0500 Date: Tue, 30 Jan 2001 13:36:26 -0500 (EST) From: "Richard B. Johnson" Reply-To: root@chaos.analogic.com To: mirabilos Cc: Linux-Kernel ML , "Mark H. Wood" Subject: Re: Linux Post codes during runtime, possibly OT In-Reply-To: <009801c08ae8$c839a280$0100a8c0@homeip.net> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Jan 2001, mirabilos wrote: > [...] > > > > > > Now, we've found that small delays are reasonably well generated with > > > an "outb" to 0x80. So, indeed changing that to something else is going > > > to be tricky. > > > > So how bad would it be to give these people a place to leave the value > > that they want to have displayed, and have the delay code write *that* > > instead of garbage? > > Because Port &h80 is _not_ decoded by the standard PC hardware. > There are some ISA and nowadays even PCI cards that convert the value > OUTted to that port into two 7-segment-digit-LCDisplays, buffered so > you can read it from the card, but normally no chipset actually > cares about that port. (I speak of Desktop PCs.) > > I repeat: Any OUT to port &h80 is, as long as there are no special > extensions, just as well as any OUT to port &h1234 or &h4711 or > whateveryouwant as long as nothing uses it. > Since Port &h80 is now "reserved" for that POST code usage, > and it is the safest port one can use in order to delay, > Linux uses it. This is not correct. Port 0x80 is not an "unused" port. It is decoded by standard hardware: C:\>debug -i 80 AE -o 80 20 -i 80 20 -q  In this machine I do not have a 'POST-codes' board. Port 0x80 is an 8-bit read/write latch. It always has been. Cheers, Dick Johnson Penguin : Linux version 2.4.0 on an i686 machine (799.53 BogoMips). "Memory is like gasoline. You use it up when you are running. Of course you get it all back when you reboot..."; Actual explanation obtained from the Micro$oft help desk. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/