ANDROID: ARM: convert build of appended dtb zImage to list of dtbs

Allow CONFIG_BUILD_ARM_APPENDED_DTB_IMAGE_NAMES to specify
a space separated list of dtbs to append to the zImage,
and name the resulting file zImage-dtb

Change-Id: Ied5d0bafbd1d01fc1f109c15c4283de7029903c9
Signed-off-by: Colin Cross <ccross@android.com>
[rishabhb: resolved minor conflicts]
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>

arch/arm/Kconfig

@@ -1848,6 +1848,21 @@ config DEPRECATED_PARAM_STRUCT
 	  This was deprecated in 2001 and announced to live on for 5 years.
 	  Some old boot loaders still use this way.
 
+config BUILD_ARM_APPENDED_DTB_IMAGE
+	bool "Build a concatenated zImage/dtb by default"
+	depends on OF
+	help
+	  Enabling this option will cause a concatenated zImage and list of
+	  DTBs to be built by default (instead of a standalone zImage.)
+	  The image will built in arch/arm/boot/zImage-dtb
+
+config BUILD_ARM_APPENDED_DTB_IMAGE_NAMES
+	string "Default dtb names"
+	depends on BUILD_ARM_APPENDED_DTB_IMAGE
+	help
+	  Space separated list of names of dtbs to append when
+	  building a concatenated zImage-dtb.
+
 # Compressed boot loader in ROM.  Yes, we really want to ask about
 # TEXT and BSS so we preserve their values in the config files.
 config ZBOOT_ROM_TEXT

arch/arm/Makefile

@@ -307,6 +307,8 @@ libs-y				:= arch/arm/lib/ $(libs-y)
 boot := arch/arm/boot
 ifeq ($(CONFIG_XIP_KERNEL),y)
 KBUILD_IMAGE := $(boot)/xipImage
+else ifeq ($(CONFIG_BUILD_ARM_APPENDED_DTB_IMAGE),y)
+KBUILD_IMAGE := $(boot)/zImage-dtb
 else
 KBUILD_IMAGE := $(boot)/zImage
 endif
@@ -360,6 +362,9 @@ ifeq ($(CONFIG_VDSO),y)
 	$(Q)$(MAKE) $(build)=arch/arm/vdso $@
 endif
 
+zImage-dtb: vmlinux scripts dtbs
+	$(Q)$(MAKE) $(build)=$(boot) MACHINE=$(MACHINE) $(boot)/$@
+
 # We use MRPROPER_FILES and CLEAN_FILES now
 archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)

arch/arm/boot/.gitignore

@@ -3,3 +3,5 @@ zImage
 xipImage
 bootpImage
 uImage
+*.dtb
+zImage-dtb

arch/arm/boot/Makefile

@@ -29,6 +29,14 @@ export ZRELADDR INITRD_PHYS PARAMS_PHYS
 
 targets := Image zImage xipImage bootpImage uImage
 
+DTB_NAMES := $(subst $\",,$(CONFIG_BUILD_ARM_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))
+
 ifeq ($(CONFIG_XIP_KERNEL),y)
 
 cmd_deflate_xip_data = $(CONFIG_SHELL) -c \
@@ -66,6 +74,10 @@ $(obj)/compressed/vmlinux: $(obj)/Image FORCE
 $(obj)/zImage:	$(obj)/compressed/vmlinux FORCE
 	$(call if_changed,objcopy)
 
+$(obj)/zImage-dtb:	$(obj)/zImage $(DTB_OBJS) FORCE
+	$(call if_changed,cat)
+	@echo '  Kernel: $@ is ready'
+
 endif
 
 ifneq ($(LOADADDR),)

arch/arm/boot/dts/Makefile

@@ -1163,3 +1163,16 @@ dtb-$(CONFIG_ARCH_ASPEED) += \
 	aspeed-bmc-opp-witherspoon.dtb \
 	aspeed-bmc-opp-zaius.dtb \
 	aspeed-bmc-quanta-q71l.dtb
+
+DTB_NAMES := $(subst $\",,$(CONFIG_BUILD_ARM_APPENDED_DTB_IMAGE_NAMES))
+ifneq ($(DTB_NAMES),)
+DTB_LIST := $(addsuffix .dtb,$(DTB_NAMES))
+else
+DTB_LIST := $(dtb-y)
+endif
+
+targets += dtbs dtbs_install
+targets += $(DTB_LIST)
+
+always		:= $(DTB_LIST)
+clean-files	:= *.dtb

scripts/Makefile.lib

@@ -292,6 +292,12 @@ $(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
 
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
 
+# cat
+# ---------------------------------------------------------------------------
+# Concatentate multiple files together
+quiet_cmd_cat = CAT     $@
+cmd_cat = (cat $(filter-out FORCE,$^) > $@) || (rm -f $@; false)
+
 # Bzip2
 # ---------------------------------------------------------------------------