[PATCH 2/2] ARM: OMAP2+: Pad SPL binary to 8-byte alignment before DTB

[Beleswar Prasad Padhi]

On 10/01/26 00:58, Marek Vasut wrote:
> On 1/9/26 8:21 PM, Padhi, Beleswar wrote:
>> Hi Tom,
>>
>> On 1/10/2026 12:40 AM, Tom Rini wrote:
>>> On Sat, Jan 10, 2026 at 12:30:26AM +0530, Beleswar Padhi wrote:
>>>
>>>> The OMAP2 SPL linker script (also used for K3 platforms) currently uses
>>>> 4-byte alignment after the __u_boot_list section. Change this to 8-byte
>>>> alignment to meet the device tree specification requirement for DTB
>>>> alignment.
>>>>
>>>> However, this alignment directive only advances the location counter
>>>> without padding the actual binary output. When objcopy extracts
>>>> u-boot-spl-nodtb.bin, it includes only actual data, stopping at the last
>>>> byte of __u_boot_list (e.g., 0x41c359fc), not the aligned address (e.g.,
>>>> 0x41c35a00). When the FIT image containing device trees is concatenated
>>>> to the above SPL binary, it gets appended at the unaligned file size,
>>>> causing libfdt validation failure.
>>>>
>>>> To fix this, add an alignment directive inside the __u_boot_list section
>>>> itself. This forces the linker to include padding as part of the section
>>>> data, ensuring objcopy includes the padding bytes in the binary and the
>>>> appended FIT image starts at an 8-byte aligned boundary.
>>>>
>>>> Signed-off-by: Beleswar Padhi <b-padhi at ti.com>
>>>> ---
>>>>   arch/arm/mach-omap2/u-boot-spl.lds | 3 ++-
>>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm/mach-omap2/u-boot-spl.lds b/arch/arm/mach- omap2/u-boot-spl.lds
>>>> index 3bb759d8a1c..081323e6599 100644
>>>> --- a/arch/arm/mach-omap2/u-boot-spl.lds
>>>> +++ b/arch/arm/mach-omap2/u-boot-spl.lds
>>>> @@ -35,9 +35,10 @@ SECTIONS
>>>>       . = ALIGN(4);
>>>>       __u_boot_list : {
>>>>           KEEP(*(SORT(__u_boot_list*)));
>>>> +        . = ALIGN(8);
>>>>       } >.sram
>>>> -    . = ALIGN(4);
>>>> +    . = ALIGN(8);
>>>>       __image_copy_end = .;
>>>>       _end = .;
>>>>       _image_binary_end = .;
>>> Do we need both of these? Shouldn't we just need the one inside the sram
>>> section with a comment that this ensures the end of the SRAM portion is
>>> 8-byte aligned?
>>
>>
>> Yes, we need only the first directive.
>
> Would that work if the __u_boot_list section is empty ? I think it won't and you would end up with possible 4-byte alignment again.


It won't work. But having the second ALIGN(8) won't fix it either. Either we
change the whole linker script to be 8-byte aligned, or we leave a comment
on the last section saying it should be 8-byte aligned for DTB concatenation.
I think the latter is a better approach. We don't necessarily need to enforce
8-byte alignment for every section of the binary.

Thanks,
Beleswar