From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH] ACPI: Implement overriding of arbitrary ACPI tables via initrd Date: Sun, 25 Mar 2012 18:25:17 -0700 Message-ID: <4F6FC57D.3050404@zytor.com> References: <1332512984-79664-1-git-send-email-trenn@suse.de> <201203240402.38749.trenn@suse.de> <4F6D50DD.4050306@zytor.com> <201203260245.43177.trenn@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:46016 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754243Ab2CZBZi (ORCPT ); Sun, 25 Mar 2012 21:25:38 -0400 In-Reply-To: <201203260245.43177.trenn@suse.de> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Thomas Renninger Cc: eric.piel@tremplin-utc.net, vojcek@tlen.pl, dsdt@gaugusch.at, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, Lin Ming , lenb@kernel.org, robert.moore@intel.com, Al Viro On 03/25/2012 05:45 PM, Thomas Renninger wrote: > Best would be if no distro specific mkinitrd magic is needed and it's > just as easy as it is: > cp DSDT.aml /boot/initrd-test > cat /boot/initrd >>/boot/initrd-test > and add a test boot entry to grub's menu.lst or whereever. > Then developers would not have to look at distro specific implementations > (which should not exist) about how to test a table quickly. There is no distro-specific magic needed. What I'm proposing is basically what you have above, except that your DSDT.aml would be wrapped in a cpio header. What I would like to ask from you is if it makes sense to have kernel/acpi/DSDT, kernel/acpi/SSDT and so on, or just make it a single kernel/acpi member. By wrapping in a cpio container it becomes a generic mechanism. >> By the way, if "relying on the bootloader" was an option in any way > > Why exactly is a change in the bootloader not an option? > Not sure whether a version number is passed, but the magic number could be > changed for now. There are a lot of bootloaders, and one of the most commonly used ones has a very adversarial relationship with the kernel maintainers. > If the new magic number is passed, we get a linked list. The linked list stuff is already supported. This interface has been supported in the kernel since 2007. -hpa