Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756235AbbEUP4w (ORCPT ); Thu, 21 May 2015 11:56:52 -0400 Received: from mail-wg0-f41.google.com ([74.125.82.41]:36730 "EHLO mail-wg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755862AbbEUP4s (ORCPT ); Thu, 21 May 2015 11:56:48 -0400 MIME-Version: 1.0 In-Reply-To: <1432216514.26714.4.camel@misato.fc.hp.com> References: <20150520205536.32249.89779.stgit@dwillia2-desk3.amr.corp.intel.com> <20150520205621.32249.39424.stgit@dwillia2-desk3.amr.corp.intel.com> <1432216514.26714.4.camel@misato.fc.hp.com> Date: Thu, 21 May 2015 08:56:46 -0700 Message-ID: Subject: Re: [PATCH v3 02/21] libnd, nfit: initial libnd infrastructure and NFIT support From: Dan Williams To: Toshi Kani Cc: Jens Axboe , "linux-nvdimm@lists.01.org" , Neil Brown , Greg KH , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , Robert Moore , Linux ACPI , Lv Zheng , Christoph Hellwig , Ingo Molnar Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2189 Lines: 48 On Thu, May 21, 2015 at 6:55 AM, Toshi Kani wrote: > On Wed, 2015-05-20 at 16:56 -0400, Dan Williams wrote: > : >> +/* NVDIMM - NFIT table */ >> + >> +#define UUID_VOLATILE_MEMORY "4f940573-dafd-e344-b16c-3f22d252e5d0" >> +#define UUID_PERSISTENT_MEMORY "79d3f066-f3b4-7440-ac43-0d3318b78cdb" >> +#define UUID_CONTROL_REGION "f601f792-b413-5d40-910b-299367e8234c" >> +#define UUID_DATA_REGION "3005af91-865d-0e47-a6b0-0a2db9408249" >> +#define UUID_VOLATILE_VIRTUAL_DISK "5a53ab77-fc45-4b62-5560-f7b281d1f96e" >> +#define UUID_VOLATILE_VIRTUAL_CD "30bd5a3d-7541-ce87-6d64-d2ade523c4bb" >> +#define UUID_PERSISTENT_VIRTUAL_DISK "c902ea5c-074d-69d3-269f-4496fbe096f9" >> +#define UUID_PERSISTENT_VIRTUAL_CD "88810108-cd42-48bb-100f-5387d53ded3d" > > acpi_str_to_uuid() performs little-endian byte-swapping, so the UUID > strings here need to be actual values. > > For instance, UUID_PERSISTENT_MEMORY should be: > #define UUID_PERSISTENT_MEMORY "66f0d379-b4f3-4074-ac43-0d3318b78cdb" > No, the spec defines the GUID for persistent memory as: { 0x66F0D379, 0xB4F3, 0x4074, 0xAC, 0x43, 0x0D, 0x33, 0x18, 0xB7, 0x8C, 0xDB } The byte encoding for that GUID is the following (all fields stored big endian: https://en.wikipedia.org/wiki/Globally_unique_identifier#Binary_encoding) { 0x66, 0xF0, 0xD3, 0x79, 0xB4, 0xF3, 0x40,0x74, 0xAC, 0x43, 0x0D, 0x33, 0x18, 0xB7, 0x8C, 0xDB } The reverse ACPI string translation of a UUID buffer according to "ACPI 6 - 19.6.136 ToUUID (Convert String to UUID Macro)" { dd, cc, bb, aa, ff, ee, hh, gg, ii, jj, kk, ll, mm, nn, oo, pp } "aabbccdd-eeff-gghh-iijj-kkllmmnnoopp" "79d3f066-f3b4-7440-ac43-0d3318b78cdb" Indeed, v2 of this patchset got this wrong. Thanks to the sharp eyes of Bob Moore on the ACPICA team, he caught this discrepancy. It seems the ACPI spec uses the terms "GUID" and "UUID" interchangeably. -- 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/