From owner-freebsd-bugs Sat Jan 13 15:24:37 1996 Return-Path: owner-bugs Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id PAA23608 for bugs-outgoing; Sat, 13 Jan 1996 15:24:37 -0800 (PST) Received: from linux4nn.gn.iaf.nl (root@linux4nn.gn.iaf.nl [193.67.144.34]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id PAA23597 for ; Sat, 13 Jan 1996 15:24:28 -0800 (PST) Received: from uni4nn.iaf.nl (root@uni4nn.iaf.nl [193.67.144.33]) by linux4nn.gn.iaf.nl (8.6.9/8.6.9) with SMTP id AAA08139 for ; Sun, 14 Jan 1996 00:24:32 +0100 Received: by uni4nn.iaf.nl with UUCP id AA18068 (5.67b/IDA-1.5 for bugs@freebsd.org); Sun, 14 Jan 1996 00:23:41 +0100 Received: by iafnl.es.iaf.nl with UUCP id AA25453 (5.65c/IDA-1.4.4); Sat, 13 Jan 1996 23:43:45 +0100 Date: Sat, 13 Jan 1996 18:38:35 +0100 (MET) From: Geert Bosch To: bugs@freebsd.org Subject: Re: ATI Mach-64 problems in Textmode!!! Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-bugs@freebsd.org Precedence: bulk Dear developers, There is a bug in FreeBSD which leads to unexpected conflicts between serial ports and the ATI Mach-64 Xpression PCI-based video card: the FreeBSD kernel writes to the IO-port at address 0x2ec when it shouldn't, resulting in a black screen during kernel load. I experienced the bug using FreeBSD-v2.05, but I got mail from other users who had the same problem with FreeBSD-v2.1. There is a workaround for this bug, but it's not trivial and should be included in the FAQ. The IO-port at 0x2ec is used by both the sio driver and the ATI Mach. Disabling the fourth sio-port (at 0x2e8) should prevent sio from accessing the port, but unfortunately it does not. The work-around is to disable *all* serial ports and then build a custom kernel with a patch in sio.c to remove the address of the fourth serial port. Note that not all ATI Mach-64 cards exhibit this problem, as it seems it only surfaces with the ATI Mach-64 Xpression. Could you please add this to the FAQ and/or change the drivers so other people won't have as much trouble in getting even the boot-floppy to load as I had. Thanks for your hard work! Greetings, Geert PS. Could you in any case send a confirmation of my bug-report? E-Mail: geert@sun3.iaf.nl Phone: +31-53-4303054 ---------- Forwarded message ---------- Date: Sat, 13 Jan 96 14:32:30 GMT From: John Lucas To: geert@fozzie.sun3.iaf.nl Subject: Re: ATI Mach-64 problems in Textmode!!! >I have a very strange problem with FreeBSD v2.05R (didn't receive the >new one yet) and my ATI Mach-64 Xpression PCI videocard with 1 MB DRAM. >The kernel loads fine, but after that I get (when it starts >initializing hardware) a strange video-effect occurs and my screen >turns black and it looks like the (black) picture isn't synchronized >anymore. I tried to disable all devices which were not needed, >(including the possibly conflicting 4th serial port at 0x2E8) but that >didn'd help. Replacing the ATI Mach-64 with an old ET4000 fixed the >problem. Note that I'm not talking about X-Windows, but just the >normal text-mode. > You will have to disable ALL of your sio ports to get around this problem. Once installed you can generate a new kernal w/o code for sio3 AND you will need to change the file /usr/src/sys/i386/isa/sio.c. Change: static Port_t likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, 0x2e8, }; to static Port_t likely_com_ports[] = { 0x3f8, 0x2f8, 0x3e8, }; If this isn't in the FAQ it should be. I am running v2.1-SNAPxxxx and I had the same problem with the same hardware (ATI Xpression) and it works fine now (actually I dropped sio2 and sio3, since I only have 2 com ports). | John Lucas jlucas@uvi.edu | | Academic Computing NIC Handle: JL423 | | University of the Virgin Islands (809) 693-1216 | | St. Thomas, VI 00802 http://www.uvi.edu/jlucas.html |