From owner-freebsd-arm@FreeBSD.ORG Thu Feb 12 17:15:37 2015 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 926301AA for ; Thu, 12 Feb 2015 17:15:37 +0000 (UTC) Received: from mail-qa0-x234.google.com (mail-qa0-x234.google.com [IPv6:2607:f8b0:400d:c00::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 44F47EBC for ; Thu, 12 Feb 2015 17:15:37 +0000 (UTC) Received: by mail-qa0-f52.google.com with SMTP id v10so8581843qac.11 for ; Thu, 12 Feb 2015 09:15:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc:content-type:content-transfer-encoding; bh=uXLBtnu425MaM5vS6nPsTHlMLWxYrngS3eEG92cVvNY=; b=kW9LxxQb4Bnz3gt3t10DtolAvta3Vbp0i9a53ReuUAmO11Npbu9jWQp9jSHjL9nLl0 LX/OBQhqzqAZ/p8C4Vl15N7r3l1bWPf7+BGX+Zec2Qzn+IghHFXOM/fTgLsCtnop7r3C sBrS129vVggWC8LxyxTVPXW4WM2acajEpMBkC5QJ2bFIO6qzRr5iZ3c3JkSmEvcCDprc bnCuICRED5OAcIabAdxZdHjn/g+eLRss3Aa7j6/+8GBW5Qlb3uubMkVRmkGCqNlM/Wua yjf44xFo5WKxl+M2sG7HGs66iIpZntF9w3FUPVg6/CydVUdi1DQEXwUeueKyH9IKN0Of /qpA== X-Received: by 10.140.94.6 with SMTP id f6mr12282997qge.38.1423761336370; Thu, 12 Feb 2015 09:15:36 -0800 (PST) MIME-Version: 1.0 Sender: carpeddiem@gmail.com Received: by 10.140.39.209 with HTTP; Thu, 12 Feb 2015 09:15:16 -0800 (PST) In-Reply-To: <228428CC-4042-4902-90A4-E7040F4BFFF5@bsdimp.com> References: <607BF592-A09B-4DB4-9872-C9E63066AB57@bsdimp.com> <71E9C1B9-F819-420B-90A5-A36D58E71817@bsdimp.com> <228428CC-4042-4902-90A4-E7040F4BFFF5@bsdimp.com> From: Ed Maste Date: Thu, 12 Feb 2015 12:15:16 -0500 X-Google-Sender-Auth: J_FfPHFC09jy1ZA1RjoIzeE6g6M Message-ID: Subject: Re: FreeBSD/arm64 MACHINE/MACHINE_ARCH identification To: Warner Losh Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-arm@freebsd.org" X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Feb 2015 17:15:37 -0000 >> Oh - I don't care what directory Linux puts the kernel source in, only >> what's reported by uname. As far as I can tell that has always been >> aarch64 for uname -m. > > Traditionally in Linux, they have been a matched set. Ok, it appears they may have abandoned this. >> We might decide that "uname -m" has to be aarch64 to match >> expectations of third-party software set by other operating systems. >> If that in turn means we have to move the kernel source, so be it. > > This one I=E2=80=99m not on board with. You=E2=80=99ve not made a compell= ing case for > it yet. That's why I said "we might decide" -- I'm not sure myself. However, there's no backwards compatibility concern here, we've never had a FreeBSD release that reports "arm64" for "uname -m". There's no reason for us to prefer "arm64" if everyone else uses "aarch64." Also, having arm64 for uname -m and aarch64 for uname -p seems a bit odd. > One other area that these choices impact the system is in the MACHINE_CPU= ARCH > macro, which is derived from MACHINE_ARCH (-p), so it might need another > special case. There's a special case already for TARGET_TRIPLE :C/arm64/aarch64/. > There=E2=80=99s also a number of places we test different of these variab= les > against arm* that will need to be audited if we make this change = as well. > Thankfully, there=E2=80=99s only about a dozen. While not externally visi= ble, any change here > will need to make sure we=E2=80=99re consistent when building. Yes, I'm not too worried about the naming within our tree - dealing with a few dozen tests in the FreeBSD tree is much easier than trying to change expectations of third-party software.