[PATCH] of: unittest: Statically apply overlays using fdtoverlay

[Viresh Kumar]

Now that fdtoverlay is part of the kernel build, start using it to test
the unitest overlays we have by applying them statically.

The file overlay_base.dtb have symbols of its own and we need to apply
overlay.dtb to overlay_base.dtb alone first to make it work, which gives
us intermediate-overlay.dtb file.

The intermediate-overlay.dtb file along with all other overlays is them
applied to testcases.dtb to generate the master.dtb file.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

---
Depends on:

https://lore.kernel.org/lkml/be5cb12a68d9ac2c35ad9dd50d6b168f7cad6837.1609996381.git.viresh.kumar@xxxxxxxxxx/

I have kept the .dtb naming for overlays for now, lets see how we do it
eventually.

Rob/Frank, this doesn't work properly right now. Maybe I missed how
these overlays must be applied or there is a bug in fdtoverlay.

The master.dtb doesn't include any nodes from overlay_base.dtb or
overlay.dtb probably because 'testcase-data-2' node isn't present in
testcases.dtb and fdtoverlay doesn't allow applying new nodes to the
root node, i.e. allows new sub-nodes once it gets phandle to the parent
but nothing can be added to the root node itself. Though I get a feel
that it works while applying the nodes dynamically and it is expected to
work here as well.

(And yeah, this is my first serious attempt at updating Makefiles, I am
sure there is a scope of improvement here :))

---
 drivers/of/unittest-data/Makefile | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
index 009f4045c8e4..f17bce85f65f 100644
--- a/drivers/of/unittest-data/Makefile
+++ b/drivers/of/unittest-data/Makefile
@@ -38,3 +38,26 @@ DTC_FLAGS_testcases += -@
 
 # suppress warnings about intentional errors
 DTC_FLAGS_testcases += -Wno-interrupts_property
+
+# Apply overlays statically with fdtoverlay
+intermediate-overlay	:= overlay.dtb
+master			:= overlay_0.dtb overlay_1.dtb overlay_2.dtb \
+			   overlay_3.dtb overlay_4.dtb overlay_5.dtb \
+			   overlay_6.dtb overlay_7.dtb overlay_8.dtb \
+			   overlay_9.dtb overlay_10.dtb overlay_11.dtb \
+			   overlay_12.dtb overlay_13.dtb overlay_15.dtb \
+			   overlay_gpio_01.dtb overlay_gpio_02a.dtb \
+			   overlay_gpio_02b.dtb overlay_gpio_03.dtb \
+			   overlay_gpio_04a.dtb overlay_gpio_04b.dtb \
+			   intermediate-overlay.dtb
+
+quiet_cmd_fdtoverlay = fdtoverlay $@
+      cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $^
+
+$(obj)/intermediate-overlay.dtb: $(obj)/overlay_base.dtb $(addprefix $(obj)/,$(intermediate-overlay))
+	$(call if_changed,fdtoverlay)
+
+$(obj)/master.dtb: $(obj)/testcases.dtb $(addprefix $(obj)/,$(master))
+	$(call if_changed,fdtoverlay)
+
+always-$(CONFIG_OF_OVERLAY) += intermediate-overlay.dtb master.dtb
-- 
2.25.0.rc1.19.g042ed3e048af