Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932487AbXBNTcy (ORCPT ); Wed, 14 Feb 2007 14:32:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932490AbXBNTcy (ORCPT ); Wed, 14 Feb 2007 14:32:54 -0500 Received: from smtp.osdl.org ([65.172.181.24]:41755 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932487AbXBNTcx (ORCPT ); Wed, 14 Feb 2007 14:32:53 -0500 Date: Wed, 14 Feb 2007 11:32:34 -0800 (PST) From: Linus Torvalds To: Jean Delvare cc: Dax Kelson , linux-kernel Subject: Re: Linus' laptop and Num lock status In-Reply-To: <20070214202144.1ddb930f.khali@linux-fr.org> Message-ID: References: <1171479361.3706.48.camel@mentorng.gurulabs.com> <20070214202144.1ddb930f.khali@linux-fr.org> 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 Content-Length: 1016 Lines: 27 On Wed, 14 Feb 2007, Jean Delvare wrote: > > On x86, the BIOS led state can be read from byte 0x97 the BIOS RAM. The > BIOS RAM is mapped at 0x400 so all we need to do is to one byte from > RAM (offset 0x497). This is how Suse's hwinfo does. Heh. Shows just how much I ever used DOS and BIOS. > But maybe the first question to ask is: why is the BIOS setting lost in > the first place? Why is the kernel resetting the led state? Ehh. Silly question. "Those flags, they do nothing." The kernel needs to know what they are in order to react correctly to them. And since you can't read them from hardware, the only way to know what they are (if you don't know about BIOS magic areas) is to SET THEM. Which is what the kernel has traditionally always done. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/