Re: [PATCH 4/8] dts: Add alternative location for upstream DTB builds

Hi Sumit,

On Thu, 14 Dec 2023 at 06:52, Sumit Garg sumit.garg@linaro.org wrote:

Allow platform owners to mirror devicetree files from devitree-rebasing directory into dts/arch/$(ARCH) (special case for dts/arch/arm64). Then build then along with any *-u-boot.dtsi file present in arch/$(ARCH)/dts directory.

Also add a new Makefile for arm64.

This will help easy migration for platforms which currently are compliant with upstream Linux kernel devicetree files.

Signed-off-by: Sumit Garg sumit.garg@linaro.org

dts/Kconfig | 11 +++++++++++ dts/Makefile | 17 ++++++++++++++--- dts/arch/arm64/Makefile | 14 ++++++++++++++ 3 files changed, 39 insertions(+), 3 deletions(-) create mode 100644 dts/arch/arm64/Makefile

diff --git a/dts/Kconfig b/dts/Kconfig index 00c0aeff893..96396f12b67 100644 --- a/dts/Kconfig +++ b/dts/Kconfig @@ -85,6 +85,17 @@ config OF_LIVE enables a live tree which is available after relocation, and can be adjusted as needed.

+config OF_UPSTREAM

•   bool "Enable use of devicetree imported from Linux kernel release"
  

•   help
  

•     Traditionally, U-boot platforms used to have their custom devicetree
  

U-Boot

(I think I mentioned this, but you thought I said U-boot...but it really is U-Boot). Perhaps grep your patches next time.

•     files or copy devicetree files from Linux kernel which are hard to
  

•     maintain and can usually get out-of-sync from Linux kernel. This
  

•     option enables platforms to migrate to devicetree-rebasing repo where
  

•     a regular sync will be maintained every major Linux kernel release
  

•     cycle. However, platforms can still have some custom u-boot specific
  

•     bits maintained as part of *-u-boot.dtsi files.
  

I'm a bit nervous about this. It means that boards chose between this dir of the local files. It means there is some effort to switch.

I wonder if we could default to using the rebasing thing, with boards having to 'opt out'? So this should be 'default y' ?

choice prompt "Provider of DTB for DT control" depends on OF_CONTROL diff --git a/dts/Makefile b/dts/Makefile index 3437e54033d..8098bf8191a 100644 --- a/dts/Makefile +++ b/dts/Makefile @@ -10,10 +10,20 @@ ifeq ($(DEVICE_TREE),) DEVICE_TREE := unset endif

+ifeq ($(CONFIG_OF_UPSTREAM),y) +ifeq ($(CONFIG_ARM64),y) +DEVICE_TREE_LOC := dts/arch/arm64

dt_dir ?

Should we move the arm64 DTs to arch/arm64 ?

What about the subdirs used in Linux?

+else +DEVICE_TREE_LOC := dts/arch/$(ARCH) +endif +else +DEVICE_TREE_LOC := arch/$(ARCH)/dts +endif

ifneq ($(EXT_DTB),) DTB := $(EXT_DTB)

else -DTB := arch/$(ARCH)/dts/$(DEVICE_TREE).dtb +DTB := $(DEVICE_TREE_LOC)/$(DEVICE_TREE).dtb endif

$(obj)/dt-$(SPL_NAME).dtb: dts/dt.dtb $(objtree)/tools/fdtgrep FORCE @@ -41,7 +51,7 @@ $(DTB): arch-dtbs

PHONY += arch-dtbs arch-dtbs:

•   $(Q)$(MAKE) $(build)=arch/$(ARCH)/dts dtbs
  

•   $(Q)$(MAKE) $(build)=$(DEVICE_TREE_LOC) dtbs
  
  

ifeq ($(CONFIG_SPL_BUILD),y) obj-$(CONFIG_OF_EMBED) := dt-spl.dtb.o @@ -65,4 +75,5 @@ clean-files := dt.dtb.S # Let clean descend into dts directories subdir- += ../arch/arc/dts ../arch/arm/dts ../arch/m68k/dts ../arch/microblaze/dts \ ../arch/mips/dts ../arch/nios2/dts ../arch/powerpc/dts ../arch/riscv/dts \

•      ../arch/sandbox/dts ../arch/sh/dts ../arch/x86/dts ../arch/xtensa/dts
  

•      ../arch/sandbox/dts ../arch/sh/dts ../arch/x86/dts ../arch/xtensa/dts        \
  

•      ./arch/arm64 ./arch/$(ARCH)
  

diff --git a/dts/arch/arm64/Makefile b/dts/arch/arm64/Makefile new file mode 100644 index 00000000000..16e9fea622d --- /dev/null +++ b/dts/arch/arm64/Makefile @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0+

+include $(srctree)/scripts/Makefile.dts

+targets += $(dtb-y)

+# Add any required device tree compiler flags here +DTC_FLAGS += -a 0x8

+PHONY += dtbs +dtbs: $(addprefix $(obj)/, $(dtb-y))

•   @:
  

+clean-files := */*.dtb */*.dtbo */*_HS

2.34.1

Regards, Simon