On Mon, Jan 12, 2026 at 10:57:46PM +0100, Marek Vasut wrote: > On 1/12/26 6:25 PM, Padhi, Beleswar wrote: > > > > On 1/12/2026 8:09 PM, Marek Vasut wrote: > > > On 1/12/26 11:11 AM, Beleswar Padhi wrote: > > > > When CONFIG_SPL_MULTI_DTB_FIT is enabled, multiple device trees are > > > > packed inside the multidtb.fit FIT image. While the individual DTBs > > > > and the FIT image start address are 8-byte aligned, the DTBs embedded > > > > within the FIT image are not guaranteed to maintain 8-byte alignment. > > > > > > Because DT properties are 4-byte aligned, and fitImage is a DT with > > > long binary strings encoded in them. But that is not the case here, > > > because the invocation does use mkimage -E . > > > > > > Therefore I see two issues: > > > - Should the code which handles LEGACY fitImages with 4-byte > > > alignment be fixed to relocate the blobs ? I think yes. > > > > > > 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? > > > - 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. 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? -- Tom
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