Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750996AbWJFM6E (ORCPT ); Fri, 6 Oct 2006 08:58:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751291AbWJFM6E (ORCPT ); Fri, 6 Oct 2006 08:58:04 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:9361 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1750996AbWJFM6B (ORCPT ); Fri, 6 Oct 2006 08:58:01 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Andrew Morton Cc: vgoyal@in.ibm.com, linux kernel mailing list , Reloc Kernel List , ak@suse.de, horms@verge.net.au, lace@jankratochvil.net, hpa@zytor.com, magnus.damm@gmail.com, lwang@redhat.com, dzickus@redhat.com, maneesh@in.ibm.com Subject: Re: [PATCH 12/12] i386 boot: Add an ELF header to bzImage References: <20061003170032.GA30036@in.ibm.com> <20061003172511.GL3164@in.ibm.com> <20061003201340.afa7bfce.akpm@osdl.org> <20061004214403.e7d9f23b.akpm@osdl.org> <20061004233137.97451b73.akpm@osdl.org> <20061005235909.75178c09.akpm@osdl.org> Date: Fri, 06 Oct 2006 06:56:03 -0600 In-Reply-To: <20061005235909.75178c09.akpm@osdl.org> (Andrew Morton's message of "Thu, 5 Oct 2006 23:59:09 -0700") Message-ID: User-Agent: Gnus/5.110004 (No Gnus v0.4) Emacs/21.4 (gnu/linux) 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: 1715 Lines: 55 Andrew Morton writes: > On Thu, 05 Oct 2006 09:29:42 -0600 > ebiederm@xmission.com (Eric W. Biederman) wrote: > >> >> In the lazy programmer school of fixes. >> >> I haven't really tested this in any configuration. >> But reading video.S it does use variable in the bootsector. >> It does seem to initialize the variables before use. >> But obviously something is missed. >> >> By zeroing the uninteresting parts of the bootsector just after we >> have determined we are loaded ok. We should ensure we are >> always in a known state the entire time. >> >> Andrew if I am right about the cause of your video not working >> when you set an enhanced video mode this should fix your boot >> problem. >> >> Singed-off-by: Eric Biederman >> >> diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S >> index 53903a4..246ac88 100644 >> --- a/arch/i386/boot/setup.S >> +++ b/arch/i386/boot/setup.S >> @@ -287,6 +287,13 @@ # Check if an old loader tries to load a >> loader_panic_mess: .string "Wrong loader, giving up..." >> >> loader_ok: >> +# Zero initialize the variables we keep in the bootsector >> + xorw %di, %di >> + xorb %al, %al >> + movw $497, %cx >> + rep >> + stosb >> + >> # Get memory size (extended mem, kB) >> >> xorl %eax, %eax > > That fixed the vga=0x263 crash. Good. We still have to be paranoid and address HPA's missing cld issues, But otherwise it looks like we are in good shape. Eric - 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/