Commit 69fc497d authored by Maxime Ripard's avatar Maxime Ripard Committed by Thomas Petazzoni
Browse files

Rework support for the device tree 



This patch introduces some support for device tree-enabled kernels.

It replaces the former BR2_LINUX_KERNEL_DTS_FILE option that was
microblaze-only, that was quite limited. This option was quite
limited, first obviously because it was restricted to microblaze,
but also because it targetted only external device tree source files,
and allowed only to build simpleImages using the custom image name
mechanism.

This patch adds a much more generic one, that can work on basically
every architecture that supports device tree. It allows to build
both device tree source file that comes with the kernel source or to
set the path to the device tree file to use so that one can use a
custom device tree.

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarArnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
parent 942fc4c5

linux/Config.in

+42 −0
Original line number Diff line number Diff line
@@ -175,6 +175,48 @@ config BR2_LINUX_KERNEL_IMAGE_TARGET_NAME 
	  Specify the kernel make target to build the kernel that you

	  need.



config BR2_LINUX_KERNEL_DTS_SUPPORT

	bool "Device tree support"

	help

	  Compile a device tree source into a device tree blob.

	  Select the dts file to compile in the options below.



if BR2_LINUX_KERNEL_DTS_SUPPORT



choice

	prompt "Device tree source"

	default BR2_LINUX_KERNEL_USE_INTREE_DTS



config BR2_LINUX_KERNEL_USE_INTREE_DTS

	bool "Use a device tree present in the kernel."

	help

	   Use a device tree source distributed with

	   the kernel sources. The dts files are located

           in the arch/<arch>/boot/dts folder.



config BR2_LINUX_KERNEL_USE_CUSTOM_DTS

	bool "Use a custom device tree file"

	help

	  Use a custom device tree file, i.e, a device

	  tree file that does not belong to the kernel

	  source tree.

endchoice



config BR2_LINUX_KERNEL_INTREE_DTS_NAME

	string "Device Tree Source file name"

	depends on BR2_LINUX_KERNEL_USE_INTREE_DTS

	help

	 Name of the device tree source file, without

	 the trailing .dts



config BR2_LINUX_KERNEL_CUSTOM_DTS_PATH

	string "Device Tree Source file path"

	depends on BR2_LINUX_KERNEL_USE_CUSTOM_DTS

	help

	  Path to the device tree source file



endif



config BR2_LINUX_KERNEL_INSTALL_TARGET

	bool "Install kernel image to /boot in target"

	depends on !BR2_TARGET_ROOTFS_INITRAMFS

linux/linux.mk

+19 −0
Original line number Diff line number Diff line
@@ -48,6 +48,12 @@ LINUX_MAKE_FLAGS = \ 
# going to be installed in the target filesystem.

LINUX_VERSION_PROBED = $(shell $(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) --no-print-directory -s kernelrelease)



ifeq ($(BR2_LINUX_KERNEL_USE_INTREE_DTS),y)

KERNEL_DTS_NAME = $(BR2_LINUX_KERNEL_INTREE_DTS_NAME)

else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_DTS),y)

KERNEL_DTS_NAME = $(basename $(notdir $(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH)))

endif



ifeq ($(BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM),y)

LINUX_IMAGE_NAME=$(call qstrip,$(BR2_LINUX_KERNEL_IMAGE_TARGET_NAME))

else
@@ -155,13 +161,25 @@ define LINUX_CONFIGURE_CMDS 
	yes '' | $(TARGET_MAKE_ENV) $(MAKE1) $(LINUX_MAKE_FLAGS) -C $(@D) oldconfig

endef



ifeq ($(BR2_LINUX_KERNEL_DTS_SUPPORT),y)

define LINUX_BUILD_DTB

	$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(KERNEL_DTS_NAME).dtb

endef

define LINUX_INSTALL_DTB

	cp $(KERNEL_ARCH_PATH)/boot/$(KERNEL_DTS_NAME).dtb $(BINARIES_DIR)/

endef

endif



# Compilation. We make sure the kernel gets rebuilt when the

# configuration has changed.

define LINUX_BUILD_CMDS

	$(if $(BR2_LINUX_KERNEL_USE_CUSTOM_DTS),

		cp $(BR2_LINUX_KERNEL_CUSTOM_DTS_PATH) $(KERNEL_ARCH_PATH)/boot/dts/)

	$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_IMAGE_NAME)

	@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then 	\

		$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) modules ;	\

	fi

	$(LINUX_BUILD_DTB)

endef
@@ -186,6 +204,7 @@ endef 


define LINUX_INSTALL_TARGET_CMDS

	$(LINUX_INSTALL_KERNEL_IMAGE_TO_TARGET)

	$(LINUX_INSTALL_DTB)

	# Install modules and remove symbolic links pointing to build

	# directories, not relevant on the target

	@if grep -q "CONFIG_MODULES=y" $(@D)/.config; then 	\