android: add makefiles to build inline with AOSP

Currently, while libcamera advertises Android support, there is no easy
way to integrate libcamera into an Android distribution.

This commit adds makefiles that allow libcamera to build inline with
AOSP, with one example of how to do so documented in [0].

Note that meson_cross.mk is adapted from the Mesa project [1].

As Android support matures, it will be useful to document how to
integrate libcamera for distribution owners [Bug].

[0] https://docs.google.com/document/d/1Sly_VH3w6wFIdE72WXijQegoHZh8IxEnJ9m0hH7GodU/edit
[1] https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/android/mesa3d_cross.mk
Bug https://bugs.libcamera.org/show_bug.cgi?id=164

Signed-off-by: Nichoals Roth <nicholas@rothemail.net>

2 files changed, 384 insertions, 0 deletions

diff --git a/android/Android.mk b/android/Android.mk
new file mode 100644
index 00000000..ff0d1472
--- /dev/null
+++ b/android/Android.mk
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (C) 2021, GlobalLogic Ukraine
+# Copyright (C) 2021, Roman Stratiienko (r.stratiienko@gmail.com)
+#
+# Android.mk - Android makefile
+#
+
+ifneq ($(filter true, $(BOARD_LIBCAMERA_USES_MESON_BUILD)),)
+
+LOCAL_PATH := $(call my-dir)
+LIBCAMERA_TOP := $(dir $(LOCAL_PATH))
+LIBCAMERA_MESON_VERSION := .0.0.1
+
+include $(CLEAR_VARS)
+
+LOCAL_SHARED_LIBRARIES := libc libexif libjpeg libyuv_chromium libdl libyaml
+MESON_GEN_PKGCONFIGS := libexif libjpeg yaml-0.1 libyuv dl
+
+ifeq ($(TARGET_IS_64_BIT),true)
+LOCAL_MULTILIB := 64
+else
+LOCAL_MULTILIB := 32
+endif
+include $(LOCAL_PATH)/meson_cross.mk
+
+ifdef TARGET_2ND_ARCH
+LOCAL_MULTILIB := 32
+include $(LOCAL_PATH)/meson_cross.mk
+endif
+
+#-------------------------------------------------------------------------------
+
+define libcamera-lib
+LOCAL_MODULE_CLASS := SHARED_LIBRARIES
+LOCAL_MODULE := $1
+LOCAL_VENDOR_MODULE := true
+LOCAL_MODULE_RELATIVE_PATH := $2
+ifdef TARGET_2ND_ARCH
+LOCAL_SRC_FILES_$(TARGET_ARCH) := $(call relative_top_path,$(LOCAL_PATH))$($3)
+LOCAL_SRC_FILES_$(TARGET_2ND_ARCH) := $(call relative_top_path,$(LOCAL_PATH))$(2ND_$3)
+LOCAL_MULTILIB := both
+else
+LOCAL_SRC_FILES := $(call relative_top_path,$(LOCAL_PATH))$($3)
+endif
+LOCAL_CHECK_ELF_FILES := false
+LOCAL_MODULE_SUFFIX := .so$(${4})
+include $(BUILD_PREBUILT)
+include $(CLEAR_VARS)
+endef
+
+__MY_SHARED_LIBRARIES := $(LOCAL_SHARED_LIBRARIES)
+include $(CLEAR_VARS)
+LOCAL_SHARED_LIBRARIES := $(__MY_SHARED_LIBRARIES)
+
+# Modules 'libcamera', produces '/vendor/lib{64}/libcamera.so'
+$(eval $(call libcamera-lib,libcamera,,LIBCAMERA_BIN,LIBCAMERA_MESON_VERSION))
+# Modules 'libcamera-base', produces '/vendor/lib{64}/libcamera-base.so'
+$(eval $(call libcamera-lib,libcamera-base,,LIBCAMERA_BASE_BIN,LIBCAMERA_MESON_VERSION))
+# Modules 'ipa_rkisp1', produces '/vendor/lib{64}/ipa_rkisp1.so'
+$(eval $(call libcamera-lib,ipa_rkisp1,,LIBCAMERA_IPA_RKISP1_BIN,))
+# Modules 'ipa_rkisp1', produces '/vendor/lib{64}/ipa_rpi.so'
+$(eval $(call libcamera-lib,ipa_rpi,,LIBCAMERA_IPA_RASPBERRYPI_BIN,))
+# Modules 'ipa_rkisp1', produces '/vendor/lib{64}/ipa_ipu3.so'
+$(eval $(call libcamera-lib,ipa_ipu3,,LIBCAMERA_IPA_IPU3_BIN,))
+# Modules 'ipa_rkisp1', produces '/vendor/lib{64}/ipa_vimc.so'
+$(eval $(call libcamera-lib,ipa_vimc,,LIBCAMERA_IPA_VIMC_BIN,))
+
+# Modules 'camera.libcamera', produces '/vendor/lib{64}/hw/camera.libcamera.so' HAL
+$(eval $(call libcamera-lib,camera.libcamera,hw,LIBCAMERA_HAL_BIN,))
+
+LOCAL_SHARED_LIBRARIES += libcamera libcamera-base ipa_rkisp1 ipa_rpi ipa_ipu3 ipa_vimc
+LOCAL_REQUIRED_MODULES := libcamera libcamera-base ipa_rkisp1 ipa_rpi ipa_ipu3 ipa_vimc
+
+$(shell mkdir -p $(TARGET_OUT_VENDOR_ETC)/rkisp1/)
+$(shell mkdir -p $(TARGET_OUT_VENDOR_ETC)/rpi/)
+$(shell mkdir -p $(TARGET_OUT_VENDOR_ETC)/ipu3/)
+$(shell mkdir -p $(TARGET_OUT_VENDOR_ETC)/vimc/)
+$(shell cp $(LIBCAMERA_IPA_RKISP1_CONFIGS)/* $(TARGET_OUT_VENDOR_ETC)/rkisp1/)
+$(shell cp $(LIBCAMERA_IPA_RASPBERRYPI_CONFIGS)/* $(TARGET_OUT_VENDOR_ETC)/rpi/)
+$(shell cp $(LIBCAMERA_IPA_IPU3_CONFIGS)/* $(TARGET_OUT_VENDOR_ETC)/ipu3/)
+$(shell cp $(LIBCAMERA_IPA_VIMC_CONFIGS)/* $(TARGET_OUT_VENDOR_ETC)/vimc/)
+
+#-------------------------------------------------------------------------------
+
+endif
diff --git a/android/meson_cross.mk b/android/meson_cross.mk
new file mode 100644
index 00000000..7a222f9c
--- /dev/null
+++ b/android/meson_cross.mk
@@ -0,0 +1,298 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (C) 2021, GlobalLogic Ukraine
+# Copyright (C) 2021, Roman Stratiienko (r.stratiienko@gmail.com)
+#
+# meson_cross.mk - Android makefile
+#
+
+# Turn "dir1/dir2/dir3/dir4" into "../../../../"
+define relative_top_path
+$(eval __s:=) \
+$(foreach tmp,$(subst /,$(space),$1),$(eval __s:=$(__s)../)) \
+$(__s)
+endef
+
+MY_PATH := $(call my-dir)
+
+AOSP_ABSOLUTE_PATH := $(realpath .)
+
+libcam_m_dummy_$(LOCAL_MULTILIB) := $(TARGET_OUT_INTERMEDIATES)/LIBCAM_DUMMY_$(LOCAL_MULTILIB)/dummy.c
+
+$(libcam_m_dummy_$(LOCAL_MULTILIB)):
+	mkdir -p $(dir $@)
+	touch $@
+
+LOCAL_SRC_FILES := $(call relative_top_path,$(MY_PATH))$(libcam_m_dummy_$(LOCAL_MULTILIB))
+LOCAL_VENDOR_MODULE := true
+LOCAL_MODULE := libcam.dummy.$(LOCAL_MULTILIB)
+
+# Prepare intermediate variables by AOSP make/core internals
+include $(BUILD_SHARED_LIBRARY)
+
+LOCAL_PATH := $(MY_PATH)
+
+link_deps := \
+	$(built_static_libraries) \
+	$(built_shared_libraries) \
+	$(built_whole_libraries) \
+	$(strip $(all_objects)) \
+	$(my_target_libatomic) \
+	$(my_target_libcrt_builtins) \
+	$(my_target_crtbegin_so_o) \
+	$(my_target_crtend_so_o)
+
+# Build using intermediate variables provided by AOSP make/core internals
+M_TARGET_PREFIX := $(my_2nd_arch_prefix)
+
+LIBCAMERA_LIB_DIR := lib$(subst 32,,$(LOCAL_MULTILIB))
+
+MESON_OUT_DIR                            := $($(M_TARGET_PREFIX)TARGET_OUT_INTERMEDIATES)/MESON_LIBCAMERA
+MESON_GEN_DIR                            := $(MESON_OUT_DIR)_GEN
+MESON_GEN_FILES_TARGET                   := $(MESON_GEN_DIR)/.timestamp
+
+$(M_TARGET_PREFIX)LIBCAMERA_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera.so
+$(M_TARGET_PREFIX)LIBCAMERA_HAL_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera-hal.so
+$(M_TARGET_PREFIX)LIBCAMERA_BASE_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera-base.so
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_RKISP1_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera/ipa_rkisp1.so
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_RASPBERRYPI_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera/ipa_rpi.so
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_IPU3_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera/ipa_ipu3.so
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_VIMC_BIN := $(MESON_OUT_DIR)/install/usr/local/lib/libcamera/ipa_vimc.so
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_RKISP1_CONFIGS := $(MESON_OUT_DIR)/install/usr/local/share/libcamera/ipa/rkisp1
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_RASPBERRYPI_CONFIGS := $(MESON_OUT_DIR)/install/usr/local/share/libcamera/ipa/raspberrypi
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_IPU3_CONFIGS := $(MESON_OUT_DIR)/install/usr/local/share/libcamera/ipa/ipu3
+$(M_TARGET_PREFIX)LIBCAMERA_IPA_VIMC_CONFIGS := $(MESON_OUT_DIR)/install/usr/local/share/libcamera/ipa/vimc
+
+LIBCAMERA_BINS := \
+	$($(M_TARGET_PREFIX)LIBCAMERA_BIN) \
+	$($(M_TARGET_PREFIX)LIBCAMERA_HAL_BIN) \
+	$($(M_TARGET_PREFIX)LIBCAMERA_BASE_BIN) \
+	$($(M_TARGET_PREFIX)LIBCAMERA_IPA_RKISP1_BIN) \
+	$($(M_TARGET_PREFIX)LIBCAMERA_IPA_RASPBERRYPI_BIN) \
+	$($(M_TARGET_PREFIX)LIBCAMERA_IPA_IPU3_BIN) \
+	$($(M_TARGET_PREFIX)LIBCAMERA_IPA_VIMC_BIN)
+
+MESON_GEN_NINJA := \
+	cd $(MESON_OUT_DIR) && PATH=/usr/bin:/usr/local/bin:$$PATH meson ./build \
+	--cross-file $(AOSP_ABSOLUTE_PATH)/$(MESON_GEN_DIR)/aosp_cross           \
+	--buildtype=release                                                      \
+	-Dandroid=enabled                                                        \
+	-Dipas=$(subst $(space),$(comma),$(BOARD_LIBCAMERA_IPAS))                \
+	-Dpipelines=$(subst $(space),$(comma),$(BOARD_LIBCAMERA_PIPELINES))      \
+	-Dsysconfdir=/vendor/etc                                                 \
+	-Dtest=false                                                             \
+	-Dwerror=false                                                           \
+	-Dallow_unsigned_ipas_in_process=true
+
+MESON_BUILD := PATH=/usr/bin:/bin:/sbin:$$PATH ninja -C $(MESON_OUT_DIR)/build
+
+$(MESON_GEN_FILES_TARGET): MESON_CPU_FAMILY := $(subst arm64,aarch64,$(TARGET_$(M_TARGET_PREFIX)ARCH))
+
+define create-pkgconfig
+echo -e "Name: $2" \
+	"\nDescription: $2" \
+	"\nVersion: $3" > $1/$2.pc
+
+endef
+
+# Taken from build/make/core/binary.mk. We need this
+# to use definitions from build/make/core/definitions.mk
+$(MESON_GEN_FILES_TARGET): PRIVATE_GLOBAL_C_INCLUDES := $(my_target_global_c_includes)
+$(MESON_GEN_FILES_TARGET): PRIVATE_GLOBAL_C_SYSTEM_INCLUDES := $(my_target_global_c_system_includes)
+
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_GLOBAL_CFLAGS := $(my_target_global_cflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_GLOBAL_CONLYFLAGS := $(my_target_global_conlyflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_GLOBAL_CPPFLAGS := $(my_target_global_cppflags)
+
+$(MESON_GEN_FILES_TARGET): PRIVATE_2ND_ARCH_VAR_PREFIX := $(M_TARGET_PREFIX)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CC := $(my_cc)
+$(MESON_GEN_FILES_TARGET): PRIVATE_LINKER := $(my_linker)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CXX := $(my_cxx)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CXX_LINK := $(my_cxx_link)
+$(MESON_GEN_FILES_TARGET): PRIVATE_YACCFLAGS := $(LOCAL_YACCFLAGS)
+$(MESON_GEN_FILES_TARGET): PRIVATE_ASFLAGS := $(my_asflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CONLYFLAGS := $(my_conlyflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CFLAGS := $(my_cflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CPPFLAGS := $(my_cppflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CFLAGS_NO_OVERRIDE := $(my_cflags_no_override)
+$(MESON_GEN_FILES_TARGET): PRIVATE_CPPFLAGS_NO_OVERRIDE := $(my_cppflags_no_override)
+$(MESON_GEN_FILES_TARGET): PRIVATE_RTTI_FLAG := $(LOCAL_RTTI_FLAG)
+$(MESON_GEN_FILES_TARGET): PRIVATE_DEBUG_CFLAGS := $(debug_cflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_C_INCLUDES := $(my_c_includes)
+$(MESON_GEN_FILES_TARGET): PRIVATE_IMPORTED_INCLUDES := $(imported_includes)
+$(MESON_GEN_FILES_TARGET): PRIVATE_LDFLAGS := $(my_ldflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_LDLIBS := $(my_ldlibs)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_GLOBAL_LDFLAGS := $(my_target_global_ldflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TIDY_CHECKS := $(my_tidy_checks)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TIDY_FLAGS := $(my_tidy_flags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_ARFLAGS := $(my_arflags)
+$(MESON_GEN_FILES_TARGET): PRIVATE_ALL_SHARED_LIBRARIES := $(built_shared_libraries)
+$(MESON_GEN_FILES_TARGET): PRIVATE_ALL_STATIC_LIBRARIES := $(built_static_libraries)
+$(MESON_GEN_FILES_TARGET): PRIVATE_ALL_WHOLE_STATIC_LIBRARIES := $(built_whole_libraries)
+$(MESON_GEN_FILES_TARGET): PRIVATE_ALL_OBJECTS := $(strip $(all_objects))
+
+$(MESON_GEN_FILES_TARGET): PRIVATE_ARM_CFLAGS := $(normal_objects_cflags)
+
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_LIBCRT_BUILTINS := $(my_target_libcrt_builtins)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_LIBATOMIC := $(my_target_libatomic)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_CRTBEGIN_SO_O := $(my_target_crtbegin_so_o)
+$(MESON_GEN_FILES_TARGET): PRIVATE_TARGET_CRTEND_SO_O := $(my_target_crtend_so_o)
+##
+
+define m-lld-flags
+  -nostdlib -Wl,--gc-sections \
+  $(PRIVATE_TARGET_CRTBEGIN_SO_O) \
+  $(PRIVATE_ALL_OBJECTS) \
+  -Wl,--whole-archive \
+  $(PRIVATE_ALL_WHOLE_STATIC_LIBRARIES) \
+  -Wl,--no-whole-archive \
+  $(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--start-group) \
+  $(PRIVATE_ALL_STATIC_LIBRARIES) \
+  $(if $(PRIVATE_GROUP_STATIC_LIBRARIES),-Wl$(comma)--end-group) \
+  $(if $(filter true,$(NATIVE_COVERAGE)),$(PRIVATE_TARGET_COVERAGE_LIB)) \
+  $(PRIVATE_TARGET_LIBCRT_BUILTINS) \
+  $(PRIVATE_TARGET_LIBATOMIC) \
+  $(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
+  $(PRIVATE_LDFLAGS) \
+  $(PRIVATE_ALL_SHARED_LIBRARIES) \
+  $(PRIVATE_TARGET_CRTEND_SO_O) \
+  $(PRIVATE_LDLIBS)
+endef
+
+define m-lld-flags-cleaned
+  $(subst prebuilts/,$(AOSP_ABSOLUTE_PATH)/prebuilts/, \
+  $(subst out/,$(AOSP_ABSOLUTE_PATH)/out/,             \
+  $(subst -Wl$(comma)--fatal-warnings,,                \
+  $(subst -Wl$(comma)--no-undefined-version,,          \
+  $(subst -Wl$(comma)--gc-sections,,                   \
+  $(patsubst %dummy.o,,                                \
+    $(m-lld-flags)))))))
+endef
+
+define m-cpp-flags
+  $(PRIVATE_TARGET_GLOBAL_CFLAGS) \
+  $(PRIVATE_TARGET_GLOBAL_CPPFLAGS) \
+  $(PRIVATE_ARM_CFLAGS) \
+  $(PRIVATE_RTTI_FLAG) \
+  $(PRIVATE_CFLAGS) \
+  $(PRIVATE_CPPFLAGS) \
+  $(PRIVATE_DEBUG_CFLAGS) \
+  $(PRIVATE_CFLAGS_NO_OVERRIDE) \
+  $(PRIVATE_CPPFLAGS_NO_OVERRIDE)
+endef
+
+define m-c-flags
+  $(PRIVATE_TARGET_GLOBAL_CFLAGS) \
+  $(PRIVATE_TARGET_GLOBAL_CONLYFLAGS) \
+  $(PRIVATE_ARM_CFLAGS) \
+  $(PRIVATE_CFLAGS) \
+  $(PRIVATE_CONLYFLAGS) \
+  $(PRIVATE_DEBUG_CFLAGS) \
+  $(PRIVATE_CFLAGS_NO_OVERRIDE)
+endef
+
+define filter-c-flags
+  $(subst -std=gnu++17,, \
+  $(subst -stdlib=libc++,, \
+  $(subst -fno-rtti,, \
+  $(patsubst  -W%,, \
+    $1))))
+endef
+
+define m-c-includes-common
+$(addprefix -I , $(PRIVATE_C_INCLUDES)) \
+$(if $(PRIVATE_NO_DEFAULT_COMPILER_FLAGS),,\
+    $(addprefix -I ,\
+        $(filter-out $(PRIVATE_C_INCLUDES), \
+            $(PRIVATE_GLOBAL_C_INCLUDES))) \
+    $(addprefix -isystem ,\
+        $(filter-out $(PRIVATE_C_INCLUDES), \
+            $(PRIVATE_GLOBAL_C_SYSTEM_INCLUDES))))
+endef
+
+ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 30; echo $$?), 0)
+# Android 11+
+define m-c-includes
+$(foreach i,$(PRIVATE_IMPORTED_INCLUDES),$(EXPORTS.$(i)))\
+$(m-c-includes-common)
+endef
+define postprocess-includes
+endef
+else
+# Android 10,9
+$(MESON_GEN_FILES_TARGET): PRIVATE_IMPORT_INCLUDES := $(import_includes)
+define postprocess-includes
+	echo " $$(cat $(PRIVATE_IMPORT_INCLUDES)) " > $(MESON_GEN_DIR)/import_includes && \
+	sed -i  -e ':a;N;$$!ba;s/\n/ /g'                                  \
+		-e 's# \{2,\}# #g'                                        \
+		-e 's# -isystem # -isystem#g'                             \
+		-e 's# -I # -I#g'                                         \
+		-e 's# -I# -I$(AOSP_ABSOLUTE_PATH)/#g'                    \
+		-e 's# -isystem# -isystem$(AOSP_ABSOLUTE_PATH)/#g'        \
+		-e "s# #','#g" $(MESON_GEN_DIR)/import_includes &&        \
+	sed -i "s#<_IMPORT_INCLUDES>#$$(cat $(MESON_GEN_DIR)/import_includes)#g" $(MESON_GEN_DIR)/aosp_cross
+endef
+define m-c-includes
+<_IMPORT_INCLUDES> $(m-c-includes-common)
+endef
+endif
+
+define m-c-abs-includes
+  $(subst $(space)-isystem,$(space)-isystem$(AOSP_ABSOLUTE_PATH)/, \
+  $(subst $(space)-I, -I$(AOSP_ABSOLUTE_PATH)/, \
+  $(subst $(space)-I$(space),$(space)-I, \
+  $(subst $(space)-isystem$(space),$(space)-isystem, \
+    $(strip $(m-c-includes))))))
+endef
+
+$(MESON_GEN_FILES_TARGET): MESON_GEN_PKGCONFIGS:=$(MESON_GEN_PKGCONFIGS)
+$(MESON_GEN_FILES_TARGET): MESON_GEN_DIR:=$(MESON_GEN_DIR)
+$(MESON_GEN_FILES_TARGET): $(sort $(shell find -L $(LIBCAMERA_TOP) -not -path '*/\.*'))
+	mkdir -p $(dir $@)
+	echo -e "[properties]\n"                                                                                                  \
+		"c_args = [$(foreach flag, $(call filter-c-flags,$(m-c-flags) $(m-c-abs-includes)),'$(flag)', )'']\n"             \
+		"cpp_args = [$(foreach flag, $(call filter-c-flags,$(m-cpp-flags) $(m-c-abs-includes)),'$(flag)', )'']\n"         \
+		"c_link_args = [$(foreach flag, $(m-lld-flags-cleaned),'$(flag)',)'']\n"                                          \
+		"cpp_link_args = [$(foreach flag, $(m-lld-flags-cleaned),'$(flag)',)'']\n"                                        \
+		"needs_exe_wrapper = true\n"                                                                                      \
+		"[binaries]\n"                                                                                                    \
+		"ar = '$(AOSP_ABSOLUTE_PATH)/$($($(M_TARGET_PREFIX))TARGET_AR)'\n"                                                \
+		"c = [$(foreach arg,$(PRIVATE_CC),'$(subst prebuilts/,$(AOSP_ABSOLUTE_PATH)/prebuilts/,$(arg))',)'']\n"           \
+		"cpp = [$(foreach arg,$(PRIVATE_CXX),'$(subst prebuilts/,$(AOSP_ABSOLUTE_PATH)/prebuilts/,$(arg))',)'']\n"        \
+		"c_ld = 'lld'\n"                                                                                                  \
+		"cpp_ld = 'lld'\n\n"                                                                                              \
+		"pkgconfig = ['env', 'PKG_CONFIG_LIBDIR=' + '$(AOSP_ABSOLUTE_PATH)/$(MESON_GEN_DIR)', '/usr/bin/pkg-config']\n\n" \
+		"llvm-config = '/dev/null'\n"                                                                                     \
+		"[host_machine]\n"                                                                                                \
+		"system = 'linux'\n"                                                                                              \
+		"cpu_family = '$(MESON_CPU_FAMILY)'\n"                                                                            \
+		"cpu = '$(MESON_CPU_FAMILY)'\n"                                                                                   \
+		"endian = 'little'" > $(dir $@)/aosp_cross
+
+	#
+	$(foreach pkg, $(MESON_GEN_PKGCONFIGS), $(call create-pkgconfig,$(dir $@),$(word 1, $(subst :, ,$(pkg))),$(word 2, $(subst :, ,$(pkg)))))
+	touch $@
+
+$(MESON_OUT_DIR)/.build.timestamp: MESON_GEN_NINJA:=$(MESON_GEN_NINJA)
+$(MESON_OUT_DIR)/.build.timestamp: MESON_BUILD:=$(MESON_BUILD)
+$(MESON_OUT_DIR)/.build.timestamp: $(MESON_GEN_FILES_TARGET) $(link_deps)
+	rm -rf $(dir $@)
+	mkdir -p $(dir $@)
+	mkdir -p $(dir $@)/build
+	# Meson will update timestamps in sources directory, continuously retriggering the build
+	# even if nothing changed. Copy sources into intermediate dir to avoid this effect.
+	cp -r $(LIBCAMERA_TOP)/* $(dir $@)
+	$(MESON_GEN_NINJA)
+	$(MESON_BUILD)
+	touch $@
+
+$(MESON_OUT_DIR)/install/.install.timestamp: MESON_BUILD:=$(MESON_BUILD)
+$(MESON_OUT_DIR)/install/.install.timestamp: $(MESON_OUT_DIR)/.build.timestamp
+	rm -rf $(dir $@)
+	mkdir -p $(dir $@)
+	DESTDIR=$(AOSP_ABSOLUTE_PATH)/$(dir $@) $(MESON_BUILD) install
+	touch $@
+
+$(LIBCAMERA_BINS): $(MESON_OUT_DIR)/install/.install.timestamp
+	echo "Build $@"
+	touch $@