From mboxrd@z Thu Jan 1 00:00:00 1970 From: khc@pm.waw.pl (Krzysztof Halasa) Date: Wed, 19 Apr 2006 10:47:46 +0000 Subject: [lm-sensors] Black box flight recorder for Linux Message-Id: List-Id: References: <44379AB8.6050808@superbug.co.uk> <443A4927.5040801@warmcat.com> In-Reply-To: (Krzysztof Halasa's message of "Mon, 10 Apr 2006 21:24:01 +0200") MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lkml , Andy Green Cc: lm-sensors@lm-sensors.org Hi, (Cc to lm-sensors list). > Yes, that could be used, too. It would be a bit more complicated as > different VGA cards use different access methods (i.e., different > I/O port and bit numbers). X11 drivers probably know how to drive it. BTW: I just soldered a 24C64 I^2C EEPROM (the largest I could find at home but 24C512 (64 KB) and even 24C1024 (128 KB) are available on the market) to a connector and connected it to SMBus on my Asus A7V333 mobo. I don't have code to write "printk" messages to it yet but will look at it sometime. Interesting: i2cdetect and friends can only find a custom Asus sensors chip on this bus (ASB100 chip at addresses 0x2D, 0x48 and 0x49) - and now my 24C64 at 0x57 (config address 7 = all ones). But the BIOS POST searches and finds more devices: there is something at 0x2F, 0x69, and there are (I think) DDR SDRAM EEPROMs and 0x51 and 0x52 (0x50 is an empty DIMM slot). Got this info with my "DIY" logic analyzer. I think the BIOS POST disconnects somehow the devices before loading the OS (in order to prevent data damage?). No wonder my first attempt with 24C16 which occupies all 0x50 - 0x57 addresses had to fail. I think VGA monitors respond (at least?) at 0x50 address so a 16-bit-addressable EEPROM (at least not larger than 24C2048 which IMHO aren't yet available) with all-ones I^2C address selected should do as well if connected to VGA/DVI I^2C/ACCESS.bus. -- Krzysztof Halasa From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750713AbWDSKrw (ORCPT ); Wed, 19 Apr 2006 06:47:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750721AbWDSKrw (ORCPT ); Wed, 19 Apr 2006 06:47:52 -0400 Received: from khc.piap.pl ([195.187.100.11]:3347 "EHLO khc.piap.pl") by vger.kernel.org with ESMTP id S1750713AbWDSKrv (ORCPT ); Wed, 19 Apr 2006 06:47:51 -0400 To: lkml , Andy Green Cc: lm-sensors@lm-sensors.org Subject: Re: Black box flight recorder for Linux References: <44379AB8.6050808@superbug.co.uk> <443A4927.5040801@warmcat.com> From: Krzysztof Halasa Date: Wed, 19 Apr 2006 12:47:46 +0200 In-Reply-To: (Krzysztof Halasa's message of "Mon, 10 Apr 2006 21:24:01 +0200") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, (Cc to lm-sensors list). > Yes, that could be used, too. It would be a bit more complicated as > different VGA cards use different access methods (i.e., different > I/O port and bit numbers). X11 drivers probably know how to drive it. BTW: I just soldered a 24C64 I^2C EEPROM (the largest I could find at home but 24C512 (64 KB) and even 24C1024 (128 KB) are available on the market) to a connector and connected it to SMBus on my Asus A7V333 mobo. I don't have code to write "printk" messages to it yet but will look at it sometime. Interesting: i2cdetect and friends can only find a custom Asus sensors chip on this bus (ASB100 chip at addresses 0x2D, 0x48 and 0x49) - and now my 24C64 at 0x57 (config address 7 = all ones). But the BIOS POST searches and finds more devices: there is something at 0x2F, 0x69, and there are (I think) DDR SDRAM EEPROMs and 0x51 and 0x52 (0x50 is an empty DIMM slot). Got this info with my "DIY" logic analyzer. I think the BIOS POST disconnects somehow the devices before loading the OS (in order to prevent data damage?). No wonder my first attempt with 24C16 which occupies all 0x50 - 0x57 addresses had to fail. I think VGA monitors respond (at least?) at 0x50 address so a 16-bit-addressable EEPROM (at least not larger than 24C2048 which IMHO aren't yet available) with all-ones I^2C address selected should do as well if connected to VGA/DVI I^2C/ACCESS.bus. -- Krzysztof Halasa