Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754276AbaFIUAV (ORCPT ); Mon, 9 Jun 2014 16:00:21 -0400 Received: from relay2.sgi.com ([192.48.180.65]:41081 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751879AbaFIUAT (ORCPT ); Mon, 9 Jun 2014 16:00:19 -0400 Date: Mon, 9 Jun 2014 15:00:17 -0500 From: Alex Thorlton To: Linux EFI , LKML Cc: Matt Fleming , Borislav Petkov , Russ Anderson Subject: [RFC] Best place/method to determine BIOS version? Message-ID: <20140609200017.GD2700@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi guys, We recently ran into/corrected a bug in our BIOS that was exposed by the recent updates to the way that the EFI code maps in memory during boot. Discussion here: http://comments.gmane.org/gmane.linux.kernel/1638074 Anyways, we now need to find a way to determine the BIOS version before efi_apply_memmap_quirks is called, so that we know whether or not the BIOS we're running requires the quirk. We have a function in one of our EFI runtime services that provides this information, but I'm having a lot of trouble calling this function early enough in boot. It seems that all the necessary function pointers are available well before efi_apply_memmap_quirks is called, but when trying to use efi_call_phys6 to call our function, I always hit a kernel paging error. I think the problem is that I really need to be doing this at a point where I can directly use physical addressing (the function pointer that we have stored in efi.uv_systab contains the physical address of our function) - at least that's the idea I get from our BIOS guys, but I really don't know what I'm talking about here :) Can anybody help me with how early in boot I need to make this call, and possibly with an appropriate location to stick the code in? Any advice is greatly appreciated. Thanks! - Alex -- 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/