[PATCH] kbuild: Respect CONFIG_SYS_DTC_PAD_BYTES after fdtgrep

[Marek Vasut]

On 4/22/26 3:15 AM, Simon Glass wrote:
> Hi Marek,
> 
> On Tue, 21 Apr 2026 at 12:48, Marek Vasut <marek.vasut at mailbox.org> wrote:
>>
>> On 4/20/26 6:14 AM, Simon Glass wrote:
>>> On 2026-04-20T01:23:26, Marek Vasut <marek.vasut+renesas at mailbox.org> wrote:
>>>> kbuild: Respect CONFIG_SYS_DTC_PAD_BYTES after fdtgrep
>>>>
>>>> The fdtgrep command will reduce the DT to minimum size, thus eliminating
>>>> the extra padding configured via CONFIG_SYS_DTC_PAD_BYTES. Reinstate the
>>>> extra padding by running the output DTB from fdtgrep through DTC with the
>>>> -p CONFIG_SYS_DTC_PAD_BYTES flag again in case CONFIG_SYS_DTC_PAD_BYTES
>>>> is not zero.
>>>>
>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
>>>>
>>>> scripts/Makefile.lib | 7 +++++++
>>>>    1 file changed, 7 insertions(+)
>>>
>>> Reviewed-by: Simon Glass <sjg at chromium.org>
>>
>> Is this something which can be added into fdtgrep itself btw ?
> 
> Yes I'm sure that would be possible: perhaps a flag to maintain the
> same padding as it finds in the input file.
We can not determine the padding from the input DTB file itself, so the 
option would have to take a padding parameter. But I wonder if it makes 
sense to grow fdtgrep this way, or whether using dtc to reinstate the 
padding is better.