[PATCH v3] mkimage: Default to 8-byte alignment for DTBs added via -b argument

[Marek Vasut]

On 1/22/26 6:45 PM, Tom Rini wrote:
> On Thu, Jan 22, 2026 at 10:52:47PM +0530, 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.
>>
>> This misalignment causes -FDT_ERR_ALIGNMENT failure in
>> setup_multi_dtb_fit() when locating the next available DTB within the
>> FIT blob and setting gd->fdt_blob, because of the recent libfdt
>> hardening since commit 0535e46d55d7 ("scripts/dtc: Update to upstream
>> version v1.7.2-35-g52f07dcca47c")
>>
>> The mkimage tool already supports enforcing this alignment via the -B
>> option, but users would have to specify it explicitly. This change
>> makes 8-byte alignment the default when using -b.
>>
>> Reported-by: Anshul Dalal <anshuld at ti.com>
>> Closes: https://lore.kernel.org/u-boot/DFJ950O0QM0D.380U0N16ZO19E@ti.com
>> Fixes: 0535e46d55d7 ("scripts/dtc: Update to upstream version v1.7.2-35-g52f07dcca47c")
>> Signed-off-by: Beleswar Padhi <b-padhi at ti.com>
> 
> Tested-by: Tom Rini <trini at konsulko.com>
Doesn't this enable 8-byte alignment for everything in case a DT is 
specified on mkimage command line ? That doesn't seem right ?

If I do mkimage -f auto -b ...dtb ... , then I only want the DTB to be 
8-byte aligned, all the other blobs can be 4 byte aligned just fine .