[Buildroot] board/ci20 uboot problems due to fdt headers

[Giulio Benetti]

Hello Thomas,

Il 04/06/2019 14:37, Thomas De Schampheleire ha scritto:
> El mié., 29 may. 2019 a las 22:55, Giulio Benetti
> (<giulio.benetti at micronovasrl.com>) escribió:
>>
>> Hello Arnout, Pablo,
>>
>> Il 29/05/2019 22:50, Arnout Vandecappelle ha scritto:
>>>
>>>
>>> On 29/05/2019 08:54, Paulo Matos wrote:
>>>>
>>>>
>>>> On 28/05/2019 20:22, Arnout Vandecappelle wrote:
>>>>>
>>>>>    Indeed, it was fixed by commit bf733342324 and its follow-up f437bf547c. Which
>>>>> Buildroot version are you using? Anything more recent than 2018.02.1 should no
>>>>> longer have this issue.
>>>>>
>>>>
>>>>
>>>> Apologies for not mentioning it but I am using tip of master, which is
>>>> why I was surprised when I saw this error come up again. Not doing
>>>> anything special.
>>>>
>>>> On arch `pacman -Ss dtc` installs /usr/include/libfdt.h, which seems to
>>>> conflict with the ones from uboot.
>>>>
>>>> Should I report this?
>>>
>>>    You did :-)
>>>
>>>    It can indeed easily be reproduced with the ci20 defconfig.
>>>
>>>    The issue is that in U-Boot commit 01286329b27b27eaeda045b469d41b1d9fce545a,
>>> $(SRCTREE) was renamed to $(srctree). So, any commit before that (i.e. any
>>> version before 2014.04) will not match the sed pattern from our uboot.mk and
>>> will not be fixed.
>>>
>>>    The solution is to add an addition substitution pattern in uboot.mk that does
>>> the same on SRCTREE instead of srctree.
>>>
>>>    In addition, commit 0de71d507157c4bd4fddcd3a419140d2b986eed2 moved it from
>>> libfdt to lib/libfdt. In other words, before 2010.06, the pattern matches even
>>> less... But that's easily fixed by making the lib/ part optional.
>>>
>>>    Oh, but actually, the fix simply doesn't work on older U-Boot versions -
>>> Buildroot commit f437bf547ca4484 disables it if scripts/dtc/libfdt doesn't
>>> exist... If that directory doesn't exist, the bundled libfdt.h, libfdt_env.h and
>>> fdt.h reside in ${srctree}/include. However, that directory also contains a
>>> bunch of files that may collide with the files from /usr/include that we want
>>> for host compilation...
>>>
>>>    So, I think the solution might be something like this:
>>>
>>> define UBOOT_FIXUP_LIBFDT_INCLUDE
>>>        $(Q)if [ -d $(@D)/scripts/dtc/libfdt ]; then \
>>>                mkdir -p $(@D)/scripts/dtc/libfdt; \
>>>                cd $(@D)/scripts/dts/libfdt; \
>>>                ln -s ../../../include/fdt.h .; \
>>>                ln -s ../../../include/libfdt*.h .; \
>>>        fi
>>>        $(Q)$(SED) \
>>>                's%-I$$(srctree)/lib/libfdt%-I$$(srctree)/scripts/dtc/libfdt%' \
>>>                's%-I$$(SRCTREE)\(/lib\)\?/libfdt%-I$$(SRCTREE)/scripts/dtc/libfdt%' \
>>>                $(@D)/tools/Makefile
>>> endef
>>>
>>>    Of course, this was completely untested. Any takers to create a patch from this?
> 
> I encountered the same problem with a u-boot based on 2017.05.
> I had to modify the suggestion above slightly:
> - the if check should be negated
> - typo 'dts' -> 'dtc' in the cd
> - extra header file libfdt_internal.h
> - escaping the '$' which has a regex meaning inside sed
> - addition of '-e' on the second sed expression, first one is already
> part of $(SED).
> 
> Following works for me:
> 
> define UBOOT_FIXUP_LIBFDT_INCLUDE
>          $(Q)if [ ! -d $(@D)/scripts/dtc/libfdt ]; then \
>                  mkdir -p $(@D)/scripts/dtc/libfdt; \
>                  cd $(@D)/scripts/dtc/libfdt; \
>                  ln -s ../../../include/fdt.h .; \
>                  ln -s ../../../include/libfdt*.h .; \
>                  ln -s ../../../lib/libfdt/libfdt_internal.h .; \
>          fi
>          $(Q)$(SED) \
> 
> 's%-I\$$(srctree)/lib/libfdt%-I$$(srctree)/scripts/dtc/libfdt%' \
>                  -e
> 's%-I\$$(SRCTREE)\(/lib\)\?/libfdt%-I$$(SRCTREE)/scripts/dtc/libfdt%'
> \
>                  $(@D)/tools/Makefile
> endef
> 
> 
> The seemingly unbalanced '-e' could be avoided by moving the two
> substitutions in one command, separated with semicolon, as follows:
> 
>          $(Q)$(SED) \
> 
> 's%-I\$$(srctree)/lib/libfdt%-I$$(srctree)/scripts/dtc/libfdt%; \
> 
> s%-I\$$(SRCTREE)\(/lib\)\?/libfdt%-I$$(SRCTREE)/scripts/dtc/libfdt%' \
>                  $(@D)/tools/Makefile
> 
> 
>>
>> Here I am :)
>> Going to work on it soon.
> 
> Giulio, will you test this modified change in your case?

Unfortunately I don't have time for this at the moment and I barely read 
what's the topic.
So feel free to take over this patch.

Best regards
-- 
Giulio Benetti
CTO

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