From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mauro Carvalho Chehab Date: Wed, 21 Oct 2020 06:45:18 +0000 Subject: Re: [PATCH 2/2] dt: Remove booting-without-of.rst Message-Id: <20201021084518.1eab6481@coco.lan> List-Id: References: <20201008142420.2083861-1-robh@kernel.org> <20201008142420.2083861-2-robh@kernel.org> In-Reply-To: <20201008142420.2083861-2-robh@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Rob Herring Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Frank Rowand , Geert Uytterhoeven , Michael Ellerman , Thomas Bogendoerfer , Jonathan Corbet , Paul Mackerras , Yoshinori Sato , Rich Felker , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org, linux-doc@vger.kernel.org, linux-sh@vger.kernel.org, Benjamin Herrenschmidt Hi Rob, Em Thu, 8 Oct 2020 09:24:20 -0500 Rob Herring escreveu: > booting-without-of.rstt is an ancient document that first outlined > Flattened DeviceTree on PowerPC initially. The DT world has evolved a > lot in the 15 years since and booting-without-of.rst is pretty stale. > The name of the document itself is confusing if you don't understand the > evolution from real 'OpenFirmware'. Most of what booting-without-of.rst > contains is now in the DT specification (which evolved out of the > ePAPR). The few things that weren't documented in the DT specification > are now. > > All that remains is the boot entry details, so let's move these to arch > specific documents. The exception is arm which already has the same > details documented. Removing this document caused a warning at Documentation/arm/booting.rst: $ ./scripts/documentation-file-ref-check Documentation/arm/booting.rst: Documentation/devicetree/booting-without-of.rst as it mentions that the DTB format is described on booting-without-of.rst: 4b. Setup the device tree ------------------------- The boot loader must load a device tree image (dtb) into system ram at a 64bit aligned address and initialize it with the boot data. The dtb format is documented in Documentation/devicetree/booting-without-of.rst. The kernel will look for the dtb magic value of 0xd00dfeed at the dtb physical address to determine if a dtb has been passed instead of a tagged list. So, I guess that such part of the document needs to be moved to booting.rst. Thanks, Mauro