From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 965A229A0 for ; Thu, 19 Jun 2025 00:18:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750292289; cv=none; b=iyVPPO9NP83L6Psse7H9KKlC//iwhcH+woTKN4XH3Vs8lS6Ee3GszeabH1xXWl1SBTyCGHy6r8bRcBYwhUCC4wNF+vGcifboy4eOc9LbDEp/7GNwyeGVoyVAwDJbrFYiPJnUrS2a5F/nr4fxvUclx9G2dMSkkKI9dF0V99WnjzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750292289; c=relaxed/simple; bh=sjAxAEbzDUtghp3mTExJXABH4AX1rdTHuAgNxoiVT8w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ppxyK7Q5zTriGeG0S4o9OM7kN8Yc1Tzf4dO2WHHY0akdiisLbkQkX9BIGZBK4K3m4zXaEXMGRnyrl+X0irxJqrwreaOFFqP4gfOWJl0hjhndM0dhoQAzpaam6iQ5zgWVtW96G+yugJqiLi2jBw7zk42E9R5TT8qAAeFR3W1kNxs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V+t34tdr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V+t34tdr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B441FC4CEE7; Thu, 19 Jun 2025 00:18:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750292289; bh=sjAxAEbzDUtghp3mTExJXABH4AX1rdTHuAgNxoiVT8w=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=V+t34tdrG9oBCSKBtjALxbbY7tBFUqQlWOzGeINWERuH1tsdMgBUR4aOZVI4ki4pH T8NjNYCTg2BwXDTP8zGcDZWzHWRejnKZtfe4lrsesWOJfX4JexQE/jd3fSu1eFRkvc ZkNWOKLvJ6VISguH7POQ2H1LfD5Q3CmH+vzBH7MJUHXw0PtK7ITN9tkRFO17purrGy UsW8pieOYFrqv8S49aifX/YVjWI8JIRe2RVd3sz7q9QeCg1veuknF5dj8c8RRauBal vO0MEgry88tssl7L0eu7IpiygM7LEdk67qaCnW25XoHYfo249CKVWNEv6vXc400IUV IB4J8fYJ7gqWQ== Message-ID: Date: Thu, 19 Jun 2025 10:18:04 +1000 Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Question on BIGGEST_ALIGNMENT in GCC on NetBSD/m68k To: Finn Thain Cc: John Paul Adrian Glaubitz , Geert Uytterhoeven , port-m68k , debian-68k , linux-m68k References: <022ab204-7be9-4f6a-a92f-2601fae1f146@vivier.eu> <5d8619dfe4134319b558684209f2b89c5c1447cf.camel@physik.fu-berlin.de> <889f54af-2317-ee51-cea5-47d813683944@linux-m68k.org> <5de0835e46f8c2479668fe5fe98f8e0d230cbfce.camel@physik.fu-berlin.de> <0b09dcea10c9bab4a50b2599ef8ac59b89f09b3e.camel@physik.fu-berlin.de> <8eb87c55-95c2-0c73-4941-6e8732266220@linux-m68k.org> <4c0581c5baccf73e96e53d755e70b57b23ba1da4.camel@physik.fu-berlin.de> <29677f1e81b42c87926875109907485e41587883.camel@physik.fu-berlin.de> <38c670cc-6169-4720-a883-c34df26e1a4f@kernel.org> Content-Language: en-US From: Greg Ungerer In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 19/6/25 08:29, Finn Thain wrote: > > On Wed, 18 Jun 2025, Greg Ungerer wrote: > >> >>> It's not really necessary to enforce this on Coldfire. However, since >>> buildroot builds completely from source, it wouldn't even be a problem >>> to change the alignment there as well. >> >> Yes, that is totally right in my experience. Certainly in my ColdFire >> work it is pretty much always a build-everything approach via buildroot >> or similar. I wouldn't think an ABI change would actually worry too many >> ColdFire uses, they don't use distributions like debian on them. (I >> would love to hear from anyone who does!). >> > > That may work for end-users with a vendor BSP. But upstream developers > need to be able to swap components. In general, when debugging I often > have to run old binaries to find out whether I'm dealing with a deeper > regression or not. Also, there is the bisection problem. It's not just a > couple of distros who get to pay for an ABI break. It's the entire > ecosystem. I am sure there is value in that for some. Like I said though that has not been my experience with ColdFire. And by that I mean as the upstream maintainer of ColdFire Linux support for +20 years. I pretty mush _always_ build kernel + libs + user for testing even small kernel changes. My standard small system build takes less than 1 minute for everything. Again, I am just relating my experience with this - admittedly probably not typical of actual end users. FWIW even when I was working on shipping ColdFire based products my firmware was always a complete update, no separate kernel and user space updates. Typical of small embedded systems. I can't actually remember many times I have run with a previously compiled user space. Regards Greg