From mboxrd@z Thu Jan 1 00:00:00 1970 From: dirk.behme@de.bosch.com (Dirk Behme) Date: Fri, 14 Sep 2012 09:35:30 +0200 Subject: [Query] Does u-boot processes dtb file In-Reply-To: References: <5052D7EA.30902@de.bosch.com> Message-ID: <5052DE42.6080109@de.bosch.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 14.09.2012 09:16, Viresh Kumar wrote: > On 14 September 2012 12:38, Dirk Behme wrote: >> Working with U-Boot, to my understanding U-Boot modifies ('patches') the dtb >> read from the boot device before passing it to the kernel. It e.g. adds the >> kernel command line and the memory size you specify in U-Boot to the dtb. > > Thanks for your response. > > But, if this information is also embedded in the dts earlier, will my workaround > of filling r2 work? I think so, but I never tried it. It's on my todo list to try this ;) If you add all the information needed in the dts file and the resulting dtb file is identical to the 'patched' dtb U-Boot passes to the kernel, there should be no difference (?). > Is filling bootargs and memory size the only stuff or some other things too? I'm not totally sure on this. You could debug this: (a) Take the dtb file from your boot device. (b) dump the dtb file U-Boot passes to the kernel (i.e. do a memory dump from the pointer U-Boot passes in r2). Compare (a) and (b) with a binary diff. Best regards Dirk