The devicetree overlay driver requires the __symbols__ node to resolve phandles to the base devicetree. If Barebox has to apply the overlay to the live devicetree, the build-in devicetree must be built with the __symbols__ node. It is configurable, because adding __symbols__ significantly increases the size of the devicetree binary. When configuring Barebox, a developer should be able to enable or disable devicetree overlay support and as this only affects the build-in devicetree, which is linked to the image anyway, use a Kconfig item for configuring the __symbols__. Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx> --- Changelog: v2->v3: - make __symbols__ configurable v1->v2: none --- drivers/of/Kconfig | 17 +++++++++++++++++ scripts/Makefile.lib | 4 ++++ 2 files changed, 21 insertions(+) diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index 1bb6639c5a..fd820b26f5 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -59,3 +59,20 @@ config OF_OVERLAY not patch the live devicetree, but applies the overlays as fixup to the devicetree. Furthermore, overlays cannot be removed after they have been applied. + +config OF_OVERLAY_LIVE + depends on OF_OVERLAY + default n + bool "Support devicetree overlays on live devicetree" + help + This option allows to use devicetree overlays with the live + devicetree. It is not required to apply overlays to any other + devicetree. + + This builds the build-in devicetree with __symbols__, which + significantly increases the size of the dtb file. + + Enable this option only if you actually need the live devicetree + while applying in the devicetree overlay. This is usually the case if + applying the overlay has other side effects than changing the + devicetree. diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index c4d307ae30..ad0484de3a 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -292,6 +292,10 @@ DTC_FLAGS += -Wno-unit_address_vs_reg \ -Wno-unique_unit_address \ -Wno-pci_device_reg +ifeq ($(CONFIG_OF_OVERLAY_LIVE), y) +DTC_FLAGS += -@ +endif + # Generate an assembly file to wrap the output of the device tree compiler quiet_cmd_dt_S_dtb = DTB $@ cmd_dt_S_dtb = $(srctree)/scripts/gen-dtb-s $(subst -,_,$(*F)) $< $(CONFIG_IMD) > $@ -- 2.20.1 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
