Hi Simon, On Thu, Jan 28, 2016 at 5:39 PM, Simon Glass <sjg@xxxxxxxxxxxx> wrote: > We need a way to support more than one board per binary in U-Boot with > device tree. Various methods have been discussed. The one that seems to make > the most sense is to adjust SPL so that it can load a FIT which contains > U-Boot and several device tree binaries. This is how things with with Linux: > load a FIT and select the correct device tree to pass to Linux. Some time ago I rise question [0] to load FIT kernel directly in SPL using falcon mode. I did look at your patches and I have a feeling that with small adaptions it should be possible? Am I right or it's impossible? (Trying to use it on am33xx boards). Many thanks. > > This series: > > - Adjusts the build system to optionally build a u-boot.img in FIT format > that includes the U-Boot binary and >1 device tree files > - Adjusts SPL to support loading this > - Adds a way for SPL to determine which device tree to select (by calling a > board-specific function) > - Adjusts SPL to pass this selected device tree to U-Boot when it starts > > It would be painful to require an .its file for each board just to support > this feature. In any case various people have commented that it would be > nice not to have to write this file in general. Therefore, this series > enhances mkimage to automatically generate a FIT without a .its file. So far > it understands how to add a main image and a number of device tree files. It > does not support hashing or verified boot as yet. > > One problem with the FIT format as it stands is that all the data is inline. > This means that the entire file must be read in order to figure out what > device-tree files are available. It is then possible to copy the images into > place. > > This is not really suitable for SPL since copying can be slow, and reading > unnecessary data would make the FIT format less efficient than the legacy > format. > > Therefore this series adds a new feature to FIT which allows the images to > be stored immediately after the FIT itself ends. This makes the FIT very > small. It can be read quickly and in its entirety. Then the images can be > loaded one by one as needed. This allows SPL to support FITs containing lots > of images very efficiently. > > To achieve this, mkimage is enhanced to convert between the 'normal' and > 'external' version of a FIT file. The latter is only used for the SPL loader. > The main difference is that viewing an 'external' FIT will not show the > contents of each image. > > This series also includes a few other tidy-ups, such as moving mkimage's > tricky argument-processing code to use getopt(). > > NOTE: There are a few problems remaining with the Kconfig conversion. I'm > still fiddling with this but thought it best to send this series out for > comment in the meantime. > > This series is available at u-boot-fdt/spl-working. > [0] - http://lists.denx.de/pipermail/u-boot/2015-February/203938.html > > > _______________________________________________ > U-Boot mailing list > U-Boot@xxxxxxxxxxxxx > http://lists.denx.de/mailman/listinfo/u-boot BR, marek -- as simple and primitive as possible ------------------------------------------------- Marek Belisko - OPEN-NANDRA Freelance Developer Ruska Nova Ves 219 | Presov, 08005 Slovak Republic Tel: +421 915 052 184 skype: marekwhite twitter: #opennandra web: http://open-nandra.com -- To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
