From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (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 F10263B7778; Thu, 12 Mar 2026 07:54:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773302051; cv=none; b=Q3uihavQLZoih6WFqYB9oWBf89l3osac+bz0XbRPQs3/JtfGSiMZNyCWUDZzLBhv2a2U713ith1lDWgzrBvcadO7XxNBIFQArwVymNvCNMLS449A5sGafrT9crS9JRaQkiqnplxu14cHGkwRAUvo8+OspKPQ/CBtNOIWIbWZHkI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773302051; c=relaxed/simple; bh=Govdyk71M+I6axKdjmoCcJlG6TEPshPTfRfVWbmisTc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=WRVCX+Ixk5SnamvvR583FonRLbwOefxsixciaE7GZcEBnz8OnTP7I4J3txK3mUQId/Kp2mBui8Uzpb66z+Ih+JfrH89NILWD9gED79d8BKVYHN51/A4lnpUO1NZ3kX7TKeOni8tUEwf1wDNTe45VUEiVY6owyXsa3aYuqHaWjpU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=RYW2UpiM; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="RYW2UpiM" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id BEB86C4159A; Thu, 12 Mar 2026 07:54:28 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 1C0225FDEB; Thu, 12 Mar 2026 07:54:07 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id AF0CC103685B6; Thu, 12 Mar 2026 08:54:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1773302046; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=D5yY0c9wx3ZqgsxR2ENFj3jj2EUIEYpXbXhAsxTRZH8=; b=RYW2UpiMJfv0RfUtsX3Rn93eXp5nUxDQSCAD0zYOkzgZnxDadmituXR+m6NMkzfAr50ipq ASB1jA0VYqAzmyDLZOstE/X92+Mjue8FlG0+F8mDivHqSgLDeWFaDYRv+vNQ3w7AhDXkS0 0apA/HYHMcW83CSvgL3P2ZElvLE9+tVmjlPGcWzgcO3r1v1uW1hvrxiy8MqT7wzKNOPgFH 0C1zZvUoOhB4Z3NyMvxHU1ZlYnVm8qp32O5Yu/6t4vfywQCRaeIoKWWQJX2cKk1hK2/2A2 8T9Gjos5qtFGrPZh4TDh18i60M0E2dTC1YZ9EUZtiEKNMWaoT8mtsqBExqNmwg== Date: Thu, 12 Mar 2026 08:54:00 +0100 From: Herve Codina To: David Gibson , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Ayush Singh , Geert Uytterhoeven , devicetree-compiler@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree-spec@vger.kernel.org, Hui Pu , Ian Ray , Luca Ceresoli , Thomas Petazzoni Subject: Re: [RFC PATCH 00/15] Add support for structured tags and v18 dtb version Message-ID: <20260312085400.3a11df8b@bootlin.com> In-Reply-To: <20260210173349.636766-1-herve.codina@bootlin.com> References: <20260210173349.636766-1-herve.codina@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Hi David, On Tue, 10 Feb 2026 18:33:28 +0100 Herve Codina wrote: > Recently, I sent a RFC series related to support for metadata and addon > device-trees [1]. > > During the discussion the concept of structured tags and "unknown" tags > emerged as well as the need to have them handled as a prerequisite of > support for metadata and addon. > > The conclusion was the need for a new dtb version (v18) with support > for: > - Structured tags and based on them, "unknown" tags. > Those structured tags allow to have an standardized definition of > tags with the capability of skipping a tag and its related data > when a "unknown" tag is incountered by a given version of libfdt, > dtc and tools. Those "unknown" tags are tags defined in future > versions. Even if they exact meaning is unknown for an 'old' > version, they structure is understood and the 'old' version can skip > them without any errors if allowed. > > - Flags in the dtb header (dt_flags). > The goal of this field is to have a placeholder to specify the > type of dtb we are dealing with. For instance, addons dtb will set a > flag in this placeholder > > - A last compatible version for writing purpose. > The goal of the new dtb header field (last_comp_version_w) is to > disable globally any modification. It works similarly to > last_comp_version but for modification. It can be used to avoid any > modification that could be done by an 'old' version and could lead > to inconsistencies between the modification itself and some > "unknown" tags. > > This RFC series implements those features and leads to the v18 dtb > version. I sent this series a month ago. I know some patches have been applied but what's the plan for the remaining ones? Is there anything I can do to help move things forward? Let me know if you want some rebase and/or modification and so a new version of the series or if you need anything else that can help in moving forward. Best regards, Hervé