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>

1 files changed, 298 insertions, 0 deletions

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 $@