From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frank Rowand Subject: Re: devicetree repository separation/migration Date: Thu, 20 Feb 2014 13:15:58 -0800 Message-ID: <5306708E.1000101@gmail.com> References: <20140217180544.GU7862@titan.lakedaemon.net> <20140218155750.GS17250@pengutronix.de> <20140218181854.GB7862@titan.lakedaemon.net> <20140219090854.GW17250@pengutronix.de> <53051102.8060801@gmail.com> <53058B69.4040502@gmail.com> Reply-To: frowand.list-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:reply-to:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=zSCQrczv8x0+QX0xQCVUiQBkekG2lSmek/j+WJdJISE=; b=I/Ro02RVqn7qKmPI9BDSTAJ5E/H/tBpV/bvz7iwxgPx+nxQ7RIq928wCQcL67LkT8y 0XS0744JOyxuXXmTJirN8PvQVDUvF4vHEJuw89LxoXaOI/exuSl4bV+Fzita52RyH7zn v8tg10tL6sznZhc9RGKM9VvoLP/xXX4QxGBgxYXemeTSnjT6RvXFf+WsgK9HMkgqWsT9 ORJb5cbviTyXc7Z6zHURlVEDpj04bhYwg+SRk3s9xoLIfDxSKbqYqJRb4kBap7lf5raa 2FehLlfJGr3RL2aTAm5BbssQbfTU/NKOr8eHqpisHuKr5SgoMGnYz4kJkiw5KnlYCXDu OG8A== In-Reply-To: Sender: devicetree-spec-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Grant Likely Cc: Sascha Hauer , Tim Bird , Olof Johansson , Jason Cooper , Rob Herring , Ian Campbell , Pawel Moll , Mark Rutland , Kumar Gala , Rob Landley , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , devicetree-spec-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-compiler-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ian Campbell On 2/20/2014 12:14 AM, Grant Likely wrote: > On Thu, Feb 20, 2014 at 4:58 AM, Frank Rowand wrote: >> On 2/19/2014 1:15 PM, Grant Likely wrote: >>> On Wed, Feb 19, 2014 at 8:16 PM, Frank Rowand wrote: >>>> On 2/19/2014 1:08 AM, Sascha Hauer wrote: >>>>> On Tue, Feb 18, 2014 at 02:44:15PM -0800, Tim Bird wrote: >>>>>> I'm not in favor of separating the device tree information from the kernel. >>>>>> >>>>>> If we switch, then whatever synchronization issues other projects >>>>>> are having now with synching with the device tree info from the kernel will >>>>>> just then become the problem of the kernel developers, who will then >>>>>> have to sync with the device tree info from another repository. If the >>>>>> sync issues can't be solved now for them, why or how would it be solved >>>>>> post-separation for us? (It sounds like a zero-sum game of pain transfer >>>>>> to me.) >>>>>> >>>>>> I'm relatively unfamiliar with the arguments. Can someone provide >>>>>> a brief list of reasons this is needed, and how the inconvenience to Linux >>>>>> kernel developers will be minimized, should it proceed? >>>>> >>>> >>>> >>>>> One of the reasons for doing devicetrees is to separate the hardware >>>>> description from the code so that: >>>>> - Other OSes (and bootloaders) can use the same description to start on >>>>> a given hardware >>>>> - A generic Kernel can be started on any hardware >>>>> - A hardware describes itself, makes itself more introspecitve so we can >>>>> go away from very specialized kernels >>>> >>>> Tim knows this ^^^^. He was asking for the arguments for moving dts files >>>> out of the linux kernel source tree. >>> >>> We've made the decision that devicetree bindings need to be treated as >>> ABI, but as long as the .dts files live in the kernel there will >>> always be the temptation to just tweak things in lock-step and nobody >>> will notice. Splitting the files out gives that extra push to think >>> about whether changes to a binding will backwards compatible with a >>> tree that doesn't have those changes because the chances are a lot >>> higher that someone will hit that combination. >>> >>> The other argument is shared source between >>> BSD/U-Boot/Barebox/Linux/etc. Until we have a separate .dts repo there >>> is no good way to share the database of hardware descriptions. >> >> We could provide an easy export (see below). What do you think? > > Ian Campbell is already maintaining an export tree as a staging area > for an eventual split. He's had it up and running for almost a year > now: > > http://xenbits.xen.org/gitweb/?p=people/ianc/device-tree-rebasing.git > > g. > So there already is a "good way to share the database of hardware descriptions" in addition to the one I provided. -Frank -- To unsubscribe from this list: send the line "unsubscribe devicetree-spec" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html