From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933740AbZLFONJ (ORCPT ); Sun, 6 Dec 2009 09:13:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933673AbZLFONI (ORCPT ); Sun, 6 Dec 2009 09:13:08 -0500 Received: from one.firstfloor.org ([213.235.205.2]:59042 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932535AbZLFONG (ORCPT ); Sun, 6 Dec 2009 09:13:06 -0500 From: Andi Kleen Message-Id: <20091206313.812075626@firstfloor.org> To: ying.huang@intel.com, x86@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH] [1/3] x86: Improve CONFIG_KEXEC_JUMP description Date: Sun, 6 Dec 2009 15:13:09 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I've been puzzling what CONFIG_KEXEC_JUMP was good for. The Kconfig help was not very helpful in explaining why one want to set this option. This patch improves it a bit, based on the original commit log. It's still not fully clear, but then I couldn't find a concrete application anywhere. Cc: ying.huang@intel.com Signed-off-by: Andi Kleen --- arch/x86/Kconfig | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Index: linux-2.6.32-ak/arch/x86/Kconfig =================================================================== --- linux-2.6.32-ak.orig/arch/x86/Kconfig +++ linux-2.6.32-ak/arch/x86/Kconfig @@ -1496,8 +1496,10 @@ config KEXEC_JUMP depends on EXPERIMENTAL depends on KEXEC && HIBERNATION ---help--- - Jump between original kernel and kexeced kernel and invoke - code in physical address mode via KEXEC + Allow to call code through kexec with paging turned off and then + return to the normal kernel. This can be used to call BIOS + code for example, and to implement kexec based hibernation. + Requires uptodate kexec tools. config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)