Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030778AbWI0Ue1 (ORCPT ); Wed, 27 Sep 2006 16:34:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030780AbWI0Ue0 (ORCPT ); Wed, 27 Sep 2006 16:34:26 -0400 Received: from khc.piap.pl ([195.187.100.11]:3457 "EHLO khc.piap.pl") by vger.kernel.org with ESMTP id S1030778AbWI0UeZ (ORCPT ); Wed, 27 Sep 2006 16:34:25 -0400 To: Linus Torvalds Cc: Nicolas Mailhot , linux-kernel@vger.kernel.org, James Bottomley Subject: Re: GPLv3 Position Statement References: <43447.192.54.193.51.1159350218.squirrel@rousalka.dyndns.org> From: Krzysztof Halasa Date: Wed, 27 Sep 2006 22:34:21 +0200 In-Reply-To: (Linus Torvalds's message of "Wed, 27 Sep 2006 10:51:50 -0700 (PDT)") 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 Content-Length: 1615 Lines: 34 I generally agree with you, but... Linus Torvalds writes: > And it not at all uncommon to have a flash that simply cannot be upgraded > without opening the box. Even a lot of PC's have that: a lot (most?) PC's > have a flash that has a separate _hardware_ pin that says that it is > (possibly just partially) read-only. So in order to upgrade it, you'd > literally need to open the case up, set a jumper, and _then_ run the > program to reflash it. I think this is history. Yes, late 486s and Pentiums (60 and 66?) had a jumper protecting the flash. It's not true since ca. "Pentium 75+" days - while many boards use "bootblock" chips, it's (almost?) always unprotected (at most it just requires setting some GPIO pin(s)). The rest of flash obviously has to be R/W to support the ESCD etc. I think there are systems with 2 copies of the whole BIOS, and the user selects the copy with a jumper (probably connected directly to the most significant address line of the flash IC) - the second copy might theoretically use a R/O bootblock but I've never checked it. Most VGAs, disks, PCI cards etc. have flash chips with no protection either, and I have to say I felt much better when they used (EP)ROMs. I think almost all hardware manufacturers use a blank flash chips, programming them "in system" with things like JTAG. -- Krzysztof Halasa - 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/