From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [IPv6:2a0a:edc0:2:b01:1d::104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B70D5CA for ; Tue, 5 Dec 2023 03:49:08 -0800 (PST) Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1rATuo-0007xC-VH; Tue, 05 Dec 2023 12:48:39 +0100 Message-ID: <92a3e3b4-6f4d-4ca4-947f-db905f328d4c@pengutronix.de> Date: Tue, 5 Dec 2023 12:48:35 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9 2/2] arm64: boot: Support Flat Image Tree Content-Language: en-US To: Simon Glass , linux-arm-kernel@lists.infradead.org Cc: Masahiro Yamada , U-Boot Mailing List , Nicolas Schier , Tom Rini , Catalin Marinas , Jonathan Corbet , Nathan Chancellor , Nick Terrell , Will Deacon , linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, workflows@vger.kernel.org, Pengutronix Kernel Team References: <20231202035511.487946-1-sjg@chromium.org> <20231202035511.487946-3-sjg@chromium.org> From: Ahmad Fatoum In-Reply-To: <20231202035511.487946-3-sjg@chromium.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-doc@vger.kernel.org Hello Simon, On 02.12.23 04:54, Simon Glass wrote: > Add a script which produces a Flat Image Tree (FIT), a single file > containing the built kernel and associated devicetree files. > Compression defaults to gzip which gives a good balance of size and > performance. > > The files compress from about 86MB to 24MB using this approach. > > The FIT can be used by bootloaders which support it, such as U-Boot > and Linuxboot. It permits automatic selection of the correct > devicetree, matching the compatible string of the running board with > the closest compatible string in the FIT. There is no need for > filenames or other workarounds. > > Add a 'make image.fit' build target for arm64, as well. Use > FIT_COMPRESSION to select a different algorithm. > > The FIT can be examined using 'dumpimage -l'. > > This features requires pylibfdt (use 'pip install libfdt'). It also > requires compression utilities for the algorithm being used. Supported > compression options are the same as the Image.xxx files. For now there > is no way to change the compression other than by editing the rule for > $(obj)/image.fit > > While FIT supports a ramdisk / initrd, no attempt is made to support > this here, since it must be built separately from the Linux build. > > Signed-off-by: Simon Glass kernel_noload support is now in barebox next branch and I tested this series against it: Tested-by: Ahmad Fatoum # barebox > +"""Build a FIT containing a lot of devicetree files > + > +Usage: > + make_fit.py -A arm64 -n 'Linux-6.6' -O linux > + -f arch/arm64/boot/image.fit -k /tmp/kern/arch/arm64/boot/image.itk > + /tmp/kern/arch/arm64/boot/dts/ -E -c gzip > + > +Creates a FIT containing the supplied kernel and a directory containing the > +devicetree files. > + > +Use -E to generate an external FIT (where the data is placed after the > +FIT data structure). This allows parsing of the data without loading > +the entire FIT. > + > +Use -c to compress the data, using bzip2, gzip, lz4, lzma, lzo and > +zstd algorithms. > + > +The resulting FIT can be booted by bootloaders which support FIT, such > +as U-Boot, Linuxboot, Tianocore, etc. Feel free to add barebox to the list. Did you check whether Linuxboot and Tianocore support kernel_noload? > + fsw.property_u32('load', 0) > + fsw.property_u32('entry', 0) I still think load and entry dummy values are confusing and should be dropped. > + with fsw.add_node(f'fdt-{seq}'): > + # Get the compatible / model information > + with open(fname, 'rb') as inf: > + data = inf.read() > + fdt = libfdt.FdtRo(data) > + model = fdt.getprop(0, 'model').as_str() > + compat = fdt.getprop(0, 'compatible') > + > + fsw.property_string('description', model) > + fsw.property_string('type', 'flat_dt') > + fsw.property_string('arch', arch) > + fsw.property_string('compression', compress) > + fsw.property('compatible', bytes(compat)) > + > + with open(fname, 'rb') as inf: > + compressed = compress_data(inf, compress) > + fsw.property('data', compressed) > + return model, compat After Doug's elaboration, extracting multiple compatibles is fine by me. Cheers, Ahmad -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |