[PATCH] ARM: Align image end to 8 bytes to fit DT alignment

[Marek Vasut]

On 5/15/25 9:27 PM, Simon Glass wrote:
> Hi Marek,
> 
> On Mon, 12 May 2025 at 18:11, Marek Vasut <marek.vasut at mailbox.org> wrote:
>>
>> Align U-Boot image end to 8 bytes to make sure DT alignment requirement
>> is fulfilled. This fixes a possible failure in fdt_find_separate() in
>> case the U-Boot image is aligned to 4 Bytes and DT is appended at the
>> end at already 8 Byte aligned offset.
>>
>> Signed-off-by: Marek Vasut <marek.vasut at mailbox.org>
>> ---
>> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>> Cc: Sam Edwards <cfsworks at gmail.com>
>> Cc: Tom Rini <trini at konsulko.com>
>> Cc: u-boot at lists.denx.de
>> ---
>>   arch/arm/cpu/u-boot.lds | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/cpu/u-boot.lds b/arch/arm/cpu/u-boot.lds
>> index 817e7a983ae..b2109e03ce3 100644
>> --- a/arch/arm/cpu/u-boot.lds
>> +++ b/arch/arm/cpu/u-boot.lds
>> @@ -153,14 +153,14 @@ SECTIONS
>>                  __efi_runtime_rel_stop = .;
>>          }
>>
>> -       . = ALIGN(4);
>> +       . = ALIGN(8);
>>          __image_copy_end = .;
>>
>>          /*
>>           * if CONFIG_USE_ARCH_MEMSET is not selected __bss_end - __bss_start
>>           * needs to be a multiple of 4 and we overlay .bss with .rel.dyn
>>           */
>> -       .rel.dyn ALIGN(4) : {
>> +       .rel.dyn ALIGN(8) : {
>>                  __rel_dyn_start = .;
>>                  *(.rel*)
>>                  __rel_dyn_end = .;
>> --
>> 2.47.2
>>
> 
> Reviewed-by: Simon Glass <sjg at chromium.org>
> 
> Does the same need apply to SPL?
Yes, although in a slightly different manner. For SPL, the alignment has 
to be applied to __image_binary_end and __bss_end , see lib/fdtdec.c :

1243 static void *fdt_find_separate(void)
1244 {
1245         void *fdt_blob = NULL;
1246
1247         if (IS_ENABLED(CONFIG_SANDBOX))
1248                 return NULL;
1249
1250 #ifdef CONFIG_XPL_BUILD
1251         /* FDT is at end of BSS unless it is in a different memory 
region */
1252         if (CONFIG_IS_ENABLED(SEPARATE_BSS))
1253                 fdt_blob = (ulong *)_image_binary_end;
1254         else
1255                 fdt_blob = (ulong *)__bss_end;
1256 #else

Fixed in V2.