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

[Thomas De Schampheleire]

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?

Thanks,
Thomas