Makefile: check rootfs overlays with BR2_ROOTFS_MERGED_USR enabled

Add a step to target-finalize that checks each rootfs overlay, following
the criteria established for custom skeletons and using the same script
uesd by skeleton-custom.mk.

Add a paragraph to the documentation clarifying that rootfs overlays
don't need to contain /bin, /lib or /sbin and must not contain them when
BR2_ROOTFS_MERGED_USR is enabled.

Signed-off-by: Carlos Santos <casantos@datacom.ind.br>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
This commit is contained in:
Carlos Santos 2018-05-07 11:44:29 -03:00 committed by Arnout Vandecappelle (Essensium/Mind)
parent efc974e686
commit dc7c6487cf
2 changed files with 22 additions and 0 deletions

View File

@ -782,6 +782,22 @@ endif
@$(call MESSAGE,"Sanitizing RPATH in target tree")
$(TOPDIR)/support/scripts/fix-rpath target
# For a merged /usr, ensure that /lib, /bin and /sbin and their /usr
# counterparts are appropriately setup as symlinks ones to the others.
ifeq ($(BR2_ROOTFS_MERGED_USR),y)
@$(foreach d, $(call qstrip,$(BR2_ROOTFS_OVERLAY)), \
$(call MESSAGE,"Sanity check in overlay $(d)"); \
not_merged_dirs="$$(support/scripts/check-merged-usr.sh $(d))"; \
test -n "$$not_merged_dirs" && { \
echo "ERROR: The overlay in $(d) is not" \
"using a merged /usr for the following directories:" \
$$not_merged_dirs; \
exit 1; \
} || true$(sep))
endif # merged /usr
@$(foreach d, $(call qstrip,$(BR2_ROOTFS_OVERLAY)), \
$(call MESSAGE,"Copying overlay $(d)"); \
rsync -a --ignore-times --keep-dirlinks $(RSYNC_VCS_EXCLUSIONS) \

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@ -22,6 +22,12 @@ A filesystem overlay is a tree of files that is copied directly
etc., files called +.empty+ and files ending in +~+ are excluded from
the copy.
+
When +BR2_ROOTFS_MERGED_USR+ is enabled, then the overlay must not
contain the '/bin', '/lib' or '/sbin' directories, as Buildroot will
create them as symbolic links to the relevant folders in '/usr'. In
such a situation, should the overlay have any programs or libraries,
they should be placed in '/usr/bin', '/usr/sbin' and '/usr/lib'.
+
As shown in xref:customize-dir-structure[], the recommended path for
this overlay is +board/<company>/<boardname>/rootfs-overlay+.