Compatibility matrices: kernel req at each FCM version

* devices with Shipping FCM version
   legacy / O / O-MR1 use 3.18, 4.4, 4.9

* devices with Shipping FCM version P use 4.4 4.9

Bug: 72389707

Test: manual inspection on
$OUT/system/etc/vintf/compatibility_matrix.*.xml

Change-Id: I4f37325c0210f88e9e6d3e7136a82d50da3e93fe
diff --git a/compatibility_matrices/compatibility_matrix.mk b/compatibility_matrices/compatibility_matrix.mk
new file mode 100644
index 0000000..90713d4
--- /dev/null
+++ b/compatibility_matrices/compatibility_matrix.mk
@@ -0,0 +1,87 @@
+#
+# Copyright (C) 2018 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+ifndef LOCAL_MODULE_STEM
+$(error LOCAL_MODULE_STEM must be defined.)
+endif
+
+LOCAL_MODULE := framework_$(LOCAL_MODULE_STEM)
+LOCAL_MODULE_CLASS := ETC
+
+ifndef LOCAL_MODULE_PATH
+LOCAL_MODULE_PATH := $(TARGET_OUT)/etc/vintf
+endif
+
+GEN := $(local-generated-sources-dir)/$(LOCAL_MODULE_STEM)
+
+$(GEN): PRIVATE_ENV_VARS := $(LOCAL_ASSEMBLE_VINTF_ENV_VARS)
+$(GEN): PRIVATE_FLAGS := $(LOCAL_ASSEMBLE_VINTF_FLAGS)
+
+$(GEN): $(LOCAL_GEN_FILE_DEPENDENCIES)
+
+ifeq (true,$(strip $(LOCAL_ADD_VBMETA_VERSION)))
+ifeq (true,$(BOARD_AVB_ENABLE))
+$(GEN): $(AVBTOOL)
+# INTERNAL_AVB_SYSTEM_SIGNING_ARGS consists of BOARD_AVB_SYSTEM_KEY_PATH and
+# BOARD_AVB_SYSTEM_ALGORITHM. We should add the dependency of key path, which
+# is a file, here.
+$(GEN): $(BOARD_AVB_SYSTEM_KEY_PATH)
+# Use deferred assignment (=) instead of immediate assignment (:=).
+# Otherwise, cannot get INTERNAL_AVB_SYSTEM_SIGNING_ARGS.
+$(GEN): FRAMEWORK_VBMETA_VERSION = $$("$(AVBTOOL)" add_hashtree_footer \
+                           --print_required_libavb_version \
+                           $(INTERNAL_AVB_SYSTEM_SIGNING_ARGS) \
+                           $(BOARD_AVB_SYSTEM_ADD_HASHTREE_FOOTER_ARGS))
+else
+$(GEN): FRAMEWORK_VBMETA_VERSION := 0.0
+endif # BOARD_AVB_ENABLE
+$(GEN): PRIVATE_ENV_VARS += FRAMEWORK_VBMETA_VERSION
+endif # LOCAL_ADD_VBMETA_VERSION
+
+ifneq (,$(strip $(LOCAL_KERNEL_VERSIONS)))
+$(GEN): PRIVATE_KERNEL_CONFIG_DATA := kernel/configs
+$(GEN): PRIVATE_KERNEL_VERSIONS := $(LOCAL_KERNEL_VERSIONS)
+$(GEN): $(foreach version,$(PRIVATE_KERNEL_VERSIONS),\
+    $(wildcard $(PRIVATE_KERNEL_CONFIG_DATA)/android-$(version)/android-base*.cfg))
+$(GEN): PRIVATE_FLAGS += $(foreach version,$(PRIVATE_KERNEL_VERSIONS),\
+    --kernel=$(version):$(call normalize-path-list,\
+        $(wildcard $(PRIVATE_KERNEL_CONFIG_DATA)/android-$(version)/android-base*.cfg)))
+endif
+
+my_matrix_src_files := \
+	$(addprefix $(LOCAL_PATH)/,$(LOCAL_SRC_FILES)) \
+	$(LOCAL_GENERATED_SOURCES)
+
+$(GEN): PRIVATE_SRC_FILES := $(my_matrix_src_files)
+$(GEN): $(my_matrix_src_files) $(HOST_OUT_EXECUTABLES)/assemble_vintf
+	$(foreach varname,$(PRIVATE_ENV_VARS),$(varname)=$($(varname))) \
+		$(HOST_OUT_EXECUTABLES)/assemble_vintf \
+		-i $(call normalize-path-list,$(PRIVATE_SRC_FILES)) \
+		-o $@ \
+		$(PRIVATE_FLAGS)
+
+LOCAL_PREBUILT_MODULE_FILE := $(GEN)
+LOCAL_SRC_FILES :=
+LOCAL_GENERATED_SOURCES :=
+
+LOCAL_ADD_VBMETA_VERSION :=
+LOCAL_ASSEMBLE_VINTF_ENV_VARS :=
+LOCAL_ASSEMBLE_VINTF_FLAGS :=
+LOCAL_KERNEL_VERSIONS :=
+LOCAL_GEN_FILE_DEPENDENCIES :=
+my_matrix_src_files :=
+
+include $(BUILD_PREBUILT)