ARM64: add option to build Image.gz/dtb combo

Allows a defconfig to set a list of dtbs to concatenate with an
Image.gz to create a Image.gz-dtb.

Includes 8adb162 arm64: Fix correct dtb clean-files location

Change-Id: I0b462322d5c970f1fdf37baffece7ad058099f4a
Signed-off-by: Alex Ray <aray@google.com>

5 files changed, 51 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 871f21783866..f01073cdb4f9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -755,6 +755,21 @@ config DMI
 	  However, even with this option, the resultant kernel should
 	  continue to boot on existing non-UEFI platforms.
 
+config BUILD_ARM64_APPENDED_DTB_IMAGE
+	bool "Build a concatenated Image.gz/dtb by default"
+	depends on OF
+	help
+	  Enabling this option will cause a concatenated Image.gz and list of
+	  DTBs to be built by default (instead of a standalone Image.gz.)
+	  The image will built in arch/arm64/boot/Image.gz-dtb
+
+config BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES
+	string "Default dtb names"
+	depends on BUILD_ARM64_APPENDED_DTB_IMAGE
+	help
+	  Space separated list of names of dtbs to append when
+	  building a concatenated Image.gz-dtb.
+
 endmenu
 
 menu "Userspace binary formats"
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index cd822d8454c0..700f3fce5b35 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -73,7 +73,12 @@ libs-y		:= arch/arm64/lib/ $(libs-y)
 core-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 
 # Default target when executing plain make
+ifeq ($(CONFIG_BUILD_ARM64_APPENDED_DTB_IMAGE),y)
+KBUILD_IMAGE	:= Image.gz-dtb
+else
 KBUILD_IMAGE	:= Image.gz
+endif
+
 KBUILD_DTBS	:= dtbs
 
 all:	$(KBUILD_IMAGE) $(KBUILD_DTBS)
@@ -100,6 +105,9 @@ dtbs: prepare scripts
 dtbs_install:
 	$(Q)$(MAKE) $(dtbinst)=$(boot)/dts
 
+Image.gz-dtb: vmlinux scripts dtbs
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
 PHONY += vdso_install
 vdso_install:
 	$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso $@
diff --git a/arch/arm64/boot/.gitignore b/arch/arm64/boot/.gitignore
index 8dab0bb6ae66..eb3551131b1e 100644
--- a/arch/arm64/boot/.gitignore
+++ b/arch/arm64/boot/.gitignore
@@ -1,2 +1,3 @@
 Image
 Image.gz
+Image.gz-dtb
diff --git a/arch/arm64/boot/Makefile b/arch/arm64/boot/Makefile
index abcbba2f01ba..ddd405f88344 100644
--- a/arch/arm64/boot/Makefile
+++ b/arch/arm64/boot/Makefile
@@ -14,8 +14,18 @@
 # Based on the ia64 boot/Makefile.
 #
 
+include $(srctree)/arch/arm64/boot/dts/Makefile
+
 targets := Image Image.gz
 
+DTB_NAMES := $(subst $\",,$(CONFIG_BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES))
+ifneq ($(DTB_NAMES),)
+DTB_LIST := $(addsuffix .dtb,$(DTB_NAMES))
+else
+DTB_LIST := $(dtb-y)
+endif
+DTB_OBJS := $(addprefix $(obj)/dts/,$(DTB_LIST))
+
 $(obj)/Image: vmlinux FORCE
 	$(call if_changed,objcopy)
 
@@ -34,6 +44,9 @@ $(obj)/Image.lzma: $(obj)/Image FORCE
 $(obj)/Image.lzo: $(obj)/Image FORCE
 	$(call if_changed,lzo)
 
+$(obj)/Image.gz-dtb: $(obj)/Image.gz $(DTB_OBJS) FORCE
+	$(call if_changed,cat)
+
 install: $(obj)/Image
 	$(CONFIG_SHELL) $(srctree)/$(src)/install.sh $(KERNELRELEASE) \
 	$(obj)/Image System.map "$(INSTALL_PATH)"
diff --git a/arch/arm64/boot/dts/Makefile b/arch/arm64/boot/dts/Makefile
index eb3c42d97175..062edb210993 100644
--- a/arch/arm64/boot/dts/Makefile
+++ b/arch/arm64/boot/dts/Makefile
@@ -21,3 +21,17 @@ dtstree		:= $(srctree)/$(src)
 dtb-$(CONFIG_OF_ALL_DTBS) := $(patsubst $(dtstree)/%.dts,%.dtb, $(foreach d,$(dts-dirs), $(wildcard $(dtstree)/$(d)/*.dts)))
 
 always		:= $(dtb-y)
+
+targets += dtbs
+
+DTB_NAMES := $(subst $\",,$(CONFIG_BUILD_ARM64_APPENDED_DTB_IMAGE_NAMES))
+ifneq ($(DTB_NAMES),)
+DTB_LIST := $(addsuffix .dtb,$(DTB_NAMES))
+else
+DTB_LIST := $(dtb-y)
+endif
+targets += $(DTB_LIST)
+
+dtbs: $(addprefix $(obj)/, $(DTB_LIST))
+
+clean-files := dts/*.dtb *.dtb