[PATCH 07/10] Makefile: Align fit-dtb.blob and u-boot.itb by 64bits for 64bit systems

[Michal Simek]

Hi Andre,

On 8/19/21 5:56 PM, Andre Przywara wrote:
> On 8/19/21 12:19 PM, Michal Simek wrote:
> 
> Hi,
> 
>> Enabling MULTI_DTB_FIT and DTB_RESELECT can end up with multi DTBs in FIT
>> image placed and aligned only by 32bits (4bytes). For 64bit systems there
>> is 64bit (8bytes) alignment required. That's why make sure that
>> fit-dtb.blob and u-boot.itb as our primary target images for Xilinx
>> ZynqMP
>> are all 64bit aligned. The patch is using CONFIG_PHYS_64BIT macro to
>> identify 64bit systems (including 32bit systems with PAE).
>>
>> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
>> ---
>>
>>   Makefile | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/Makefile b/Makefile
>> index 269e353a28ad..1bbe95595efe 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -1169,6 +1169,10 @@ MKIMAGEFLAGS_fit-dtb.blob = -f auto -A $(ARCH)
>> -T firmware -C none -O u-boot \
>>       -a 0 -e 0 -E \
>>       $(patsubst %,-b arch/$(ARCH)/dts/%.dtb,$(subst
>> ",,$(CONFIG_OF_LIST))) -d /dev/null
>>   +ifeq ($(CONFIG_PHYS_64BIT),y)
> 
> Why is this restricted to 64-bit "systems"? The DT spec[1] clearly
> states that some DT parts (/memreserved/ block, for instance), must be
> 64-bit aligned, which means the whole blobs needs to be 64-bit aligned.
> Granted this probably does not cause real issues on 32-bit systems, but
> is violating the spec anyway.
> So I'd say we add the alignment requirement unconditionally.

That's even better for me and we need to make sure that dtbs itself are
aligned and also dtbs inside FIT image are aligned too.

Cheers,
Michal