OF_UPSTREAM vs. additional dtbs

[Jan Kiszka]

On 04.09.24 19:29, Frank Wunderlich wrote:
> 
> 
>> Gesendet: Mittwoch, 04. September 2024 um 19:16 Uhr
>> Von: "Jan Kiszka" <jan.kiszka at siemens.com>
>> OK, our overlay sources are on their way into mainline, will only take
>> until 6.12-rc1 to get them here. To accelerate the preparation, I ported
>> that change to a local branch - just to find out that OF_UPSTREAM has no
>> clue about DT overlays so far. And it is not just that there are no
>> build rules for them (that was quickly fixed). It's also that there is
>> no way to trigger their build for your u-boot proper.
>>
>> Are there plans for addressing this? I'm inclined to revive my patch
>> that allows to augment dtb-y from the board's config.mk. Better suggestions?
> 
> Hi
> 
> i hang also on this part, in my case i build the dtbos for the vendor and try to use fdtoverlay to merge base-dt with the defined overlays.
> 
> see commits till July 11th
> 
> https://github.com/frank-w/u-boot/commits/2024-07-bpi-ofupstream-all/
> 
> this fails because the target for fdtoverlays needs targets for the dtbos (have used the fdtoverlay target from linux)...
> but i build then without dedicated target (while building the basedt).
> 
> maybe you can help solving the "small" problem in makefile.
> 

This is close but not quite the same scenario because I only need "our" 
dtbos, and there is no need to create dtbs with them applied (they will 
be used during dt fixup in our case).

What I've now done is this:

diff --git a/dts/Kconfig b/dts/Kconfig
index 569d4be338e..7ea4fd5a79b 100644
--- a/dts/Kconfig
+++ b/dts/Kconfig
@@ -226,11 +226,11 @@ config OF_LIST
 
 config OF_OVERLAY_LIST
 	string "List of device tree overlays to include for DT control"
-	depends on SPL_LOAD_FIT_APPLY_OVERLAY
 	help
 	  This option specifies a list of device tree overlays to use for DT
 	  control. This option can then be used by a FIT generator to include
-	  the overlays in the FIT image.
+	  the overlays in the FIT image or by binman when assembling an image
+	  that uses overlays during DT fixup.
 
 choice
 	prompt "OF LIST compression"
diff --git a/scripts/Makefile.dts b/scripts/Makefile.dts
index 790f3c508f1..dc181240a21 100644
--- a/scripts/Makefile.dts
+++ b/scripts/Makefile.dts
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0+
 
 dtb-y += $(patsubst %,%.dtb,$(subst ",,$(CONFIG_DEFAULT_DEVICE_TREE) $(CONFIG_OF_LIST) $(CONFIG_SPL_OF_LIST)))
+dtb-y += $(patsubst %,%.dtbo,$(subst ",,$(CONFIG_OF_OVERLAY_LIST)))
 
 ifeq ($(CONFIG_OF_UPSTREAM_BUILD_VENDOR),y)
 ifeq ($(CONFIG_ARM64),y)


I will also provide a patch to enhance the machinery in dts/upstream
/Makefile. This apparently plays no role when building U-Boot, but it 
would still be useful for validation purposes to have overlay support 
there.

Jan

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