From mboxrd@z Thu Jan 1 00:00:00 1970 From: Igor Grinberg Date: Fri, 01 Jun 2012 09:38:17 +0300 Subject: [U-Boot] [PATCH] tegra: trimslice: fix a couple typos In-Reply-To: <4FC7A16D.8010105@wwwdotorg.org> References: <1338396350-16492-1-git-send-email-swarren@wwwdotorg.org> <4FC7302D.3020903@compulab.co.il> <201205311213.26098.marex@denx.de> <4FC7A16D.8010105@wwwdotorg.org> Message-ID: <4FC86359.1070600@compulab.co.il> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 05/31/12 19:50, Stephen Warren wrote: > On 05/31/2012 04:13 AM, Marek Vasut wrote: >> Dear Igor Grinberg, >> >>> On 05/30/12 19:45, Stephen Warren wrote: >>>> From: Stephen Warren >>>> >>>> Fix the .dts file USB unit addresses not to duplicate each-other. >>>> >>>> Fix the board name string to indicate the vendor is Compulab not NVIDIA. >>>> >>>> Signed-off-by: Stephen Warren >>> >>> Acked-by: Igor Grinberg >> >> Do we have one copy of the dts files here and one in Linux kernel tree? Are they >> the same? > > Both U-Boot and the kernel have their own copies of the .dts files. > > In general, the U-Boot copy would be identical to what's in the kernel, > or a pure subset since mostly the kernel's driver support is more > advanced, so we've added more nodes to the DT. > > That said, there are unfortunately some bizarre quirks in the way the > U-Boot parses the device tree, such as requiring the /aliases node in > order to enumerate at least some devices, the use of the Tegra clock > binding that hasn't been incorporated into the kernel yet and is used > for both clock and module reset functionality even though it's really > only intended for clock functionality, and various other small > properties that are U-Boot specific (although I forget if we managed to > eliminate these all or not). These all end up causing differences > between the two device tree files:-( Thanks for the information. I don't see any problem with having differences between the .dts files in kernel and U-Boot, because the way I see it: The .dts file we have in kernel should provide a way for a DT aware kernel to boot on even non-DT aware U-Boot (as the DT blob can be appended to the kernel binary). The .dts file in U-Boot can have a basic settings and the binary DT blob can be updated by U-Boot at run time, just before loading kernel. Also, IIRC, the intension was to remove the kernel .dts files after "all bootloaders" know to boot the DT kernel... -- Regards, Igor.