Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932286Ab1CRJNP (ORCPT ); Fri, 18 Mar 2011 05:13:15 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:36578 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932227Ab1CRJNJ (ORCPT ); Fri, 18 Mar 2011 05:13:09 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=sender:message-id:date:from:reply-to:user-agent:mime-version:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding; b=xYJkzhT6m4fT65ZMxb159LeZLnkTq5i4GODu1RCVvW6/TduHogoWEP2V+8oJJK8Q7Y jeblBaesAaygcox7qdXl/85IEQbN2fS50QJRsIWR1t+7PkTObQKXagYYe/u3SaAYy7Rh neC3rceGaSH9fA957kwSfyoOQBxO2zaRtkn24= Message-ID: <4D832220.9030704@linaro.org> Date: Fri, 18 Mar 2011 09:13:04 +0000 From: Andy Green Reply-To: andy.green@linaro.org User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110310 Fedora/3.1.9-2.fc16 Thunderbird/3.1.9 MIME-Version: 1.0 To: Roger Quadros CC: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, patches@linaro.org Subject: Re: [RFC PATCH 2/5] OMAP2+: add cpu id register to MAC address helper References: <20110312224440.27728.60593.stgit@otae.warmcat.com> <20110312225047.27728.1835.stgit@otae.warmcat.com> <4D831D4B.8090407@nokia.com> In-Reply-To: <4D831D4B.8090407@nokia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 859 Lines: 23 On 03/18/2011 08:52 AM, Somebody in the thread at some point said: >> + /* mark it as not multicast and outside official 80211 MAC namespace */ >> + >> + mac[0] = (mac[0]& ~1) | 2; > so here lies the answer to my question "From where do you get the MAC" :) > > Is there a guarantee that this MAC will work in all Ethernet setups? Yeah it's in 80211 spec. You have to buy the spec, I can't point you to it directly, but here is the wikipedia article showing the structure http://en.wikipedia.org/wiki/MAC_address#Address_details the random mac addresses generated by the kernel also use this scheme. -Andy -- 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/