On 13/01/26 05:23, Marek Vasut wrote: > On 1/12/26 11:03 PM, Tom Rini wrote: > >>>> This we can fix in the Makefile via the dd command as suggested by Tom. >>> >>> My concern is about LEGACY fitImages (means already generated ones), not >>> newly generated ones. >> >> Why is that a concern? If it's a legacy fitImage for the OS, we relocate >> the device tree already normally to be aligned. If it's a legacy >> fitImage of U-Boot, it's an old U-Boot? > > Not necessarily, it could be new U-Boot using old fitImage, for whatever > reason (falcon boot maybe ?). We should not break that. > >>>>> - Should mkimage -E align blobs to 8 bytes by default ? I think yes, >>>>> and frankly, I thought it does so already, but apparently not. >>>> >>>> >>>> This can be done, but should it be? Not all FITs demand an 8-byte >>>> alignment right? It is only the FDT which requires this. >>> Maybe if image type is flat_dt, it should be implicitly 8-byte aligned then >>> ? >> >> Well, the device tree spec says 8-byte alignment. > > 8 byte alignment of what, start of DT, right ?
Yeah from start... In this case, the FDT for OS is aligned, but the sub DT from the FIT is not aligned by 8-bytes. > >> It's not "FDT for OS" >> that's 8-byte, it's any device tree should start out 8 byte aligned, and >> everything else should then be naturally aligned. If we're looking in a >> device tree for another device tree to use in place and not relocate >> then that second tree must be aligned. >> >> Or am I missing something? > The discussion is about mkimage -E which generates DTs for U-Boot SPL use. > The DTs in those external data should likely be aligned to 8 bytes by > default, i.e. implicitly set -B 8 (they don't seem to be right now). Instead of -E, we can use '-b' which always takes DT and make sure that is 8-byte aligned by default: Usage: mkimage [-D dtc_options] [-f fit-image.its|-f auto|-f auto-conf|-F] [-b <dtb> [-b <dtb>]] [-E] [-B size] [-i <ramdisk.cpio.gz>] fit-image -b => append the device tree binary to the FIT Thanks, Beleswar
