diff --git a/core/Makefile b/core/Makefile
index b6c9f3e..45d0a23 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -835,6 +835,7 @@
 
 # -----------------------------------------------------------------
 # the ramdisk
+ifdef BUILDING_RAMDISK_IMAGE
 INTERNAL_RAMDISK_FILES := $(filter $(TARGET_RAMDISK_OUT)/%, \
 	$(ALL_GENERATED_SOURCES) \
 	$(ALL_DEFAULT_INSTALLED_MODULES))
@@ -863,6 +864,9 @@
 	@echo "make $@: ignoring dependencies"
 	$(hide) $(MKBOOTFS) -d $(TARGET_OUT) $(TARGET_RAMDISK_OUT) | $(MINIGZIP) > $(INSTALLED_RAMDISK_TARGET)
 
+endif # BUILDING_RAMDISK_IMAGE
+
+
 INSTALLED_BOOTIMAGE_TARGET := $(PRODUCT_OUT)/boot.img
 
 ifneq ($(strip $(TARGET_NO_KERNEL)),true)
@@ -1975,6 +1979,8 @@
 	        sed "s/^/-i /" | tr '\n' ' ') -o $@
 
 # -----------------------------------------------------------------
+ifdef BUILDING_SYSTEM_IMAGE
+
 # installed file list
 # Depending on anything that $(BUILT_SYSTEMIMAGE) depends on.
 # We put installed-files.txt ahead of image itself in the dependency graph
@@ -2140,6 +2146,8 @@
 endif
 endif
 
+endif # BUILDING_SYSTEM_IMAGE
+
 .PHONY: sync syncsys
 sync syncsys: $(INTERNAL_SYSTEMIMAGE_FILES)
 
@@ -2230,16 +2238,16 @@
 	echo "-D $(TARGET_OUT)" >> $@.lst
 	echo "-D $(TARGET_OUT_NOTICE_FILES)" >> $@.lst
 	echo "$(addprefix -f $(TARGET_OUT_UNSTRIPPED)/,$(PDK_SYMBOL_FILES_LIST))" >> $@.lst
-ifdef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_VENDOR_IMAGE
 	echo "-D $(TARGET_OUT_VENDOR)" >> $@.lst
 endif
-ifdef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_IMAGE
 	echo "-D $(TARGET_OUT_PRODUCT)" >> $@.lst
 endif
-ifdef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_SERVICES_IMAGE
 	echo "-D $(TARGET_OUT_PRODUCT_SERVICES)" >> $@.lst
 endif
-ifdef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_ODM_IMAGE
 	echo "-D $(TARGET_OUT_ODM)" >> $@.lst
 endif
 ifneq ($(PDK_PLATFORM_JAVA_ZIP_CONTENTS),)
@@ -2307,15 +2315,7 @@
 INTERNAL_USERDATAIMAGE_FILES := \
     $(filter $(TARGET_OUT_DATA)/%,$(ALL_DEFAULT_INSTALLED_MODULES))
 
-# Don't build userdata.img if it's extfs but no partition size
-skip_userdata.img :=
-ifdef INTERNAL_USERIMAGES_EXT_VARIANT
-ifndef BOARD_USERDATAIMAGE_PARTITION_SIZE
-skip_userdata.img := true
-endif
-endif
-
-ifneq ($(skip_userdata.img),true)
+ifdef BUILDING_USERDATA_IMAGE
 userdataimage_intermediates := \
     $(call intermediates-dir-for,PACKAGING,userdata)
 BUILT_USERDATAIMAGE_TARGET := $(PRODUCT_OUT)/userdata.img
@@ -2344,8 +2344,7 @@
 userdataimage-nodeps: | $(INTERNAL_USERIMAGES_DEPS)
 	$(build-userdataimage-target)
 
-endif # not skip_userdata.img
-skip_userdata.img :=
+endif # BUILDING_USERDATA_IMAGE
 
 # ASAN libraries in the system image - build rule.
 ASAN_OUT_DIRS_FOR_SYSTEM_INSTALL := $(sort $(patsubst $(PRODUCT_OUT)/%,%,\
@@ -2419,7 +2418,7 @@
 
 # -----------------------------------------------------------------
 # cache partition image
-ifdef BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_CACHE_IMAGE
 INTERNAL_CACHEIMAGE_FILES := \
     $(filter $(TARGET_OUT_CACHE)/%,$(ALL_DEFAULT_INSTALLED_MODULES))
 
@@ -2447,16 +2446,15 @@
 cacheimage-nodeps: | $(INTERNAL_USERIMAGES_DEPS)
 	$(build-cacheimage-target)
 
-else # BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
+else # BUILDING_CACHE_IMAGE
 # we need to ignore the broken cache link when doing the rsync
 IGNORE_CACHE_LINK := --exclude=cache
-endif # BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
+endif # BUILDING_CACHE_IMAGE
 
 # -----------------------------------------------------------------
 # system_other partition image
+ifdef BUILDING_SYSTEM_OTHER_IMAGE
 ifeq ($(BOARD_USES_SYSTEM_OTHER_ODEX),true)
-BOARD_USES_SYSTEM_OTHER := true
-
 # Marker file to identify that odex files are installed
 INSTALLED_SYSTEM_OTHER_ODEX_MARKER := $(TARGET_OUT_SYSTEM_OTHER)/system-other-odex-marker
 ALL_DEFAULT_INSTALLED_MODULES += $(INSTALLED_SYSTEM_OTHER_ODEX_MARKER)
@@ -2464,7 +2462,6 @@
 	$(hide) touch $@
 endif
 
-ifdef BOARD_USES_SYSTEM_OTHER
 INTERNAL_SYSTEMOTHERIMAGE_FILES := \
     $(filter $(TARGET_OUT_SYSTEM_OTHER)/%,\
       $(ALL_DEFAULT_INSTALLED_MODULES)\
@@ -2515,12 +2512,12 @@
 systemotherimage-nodeps: | $(INTERNAL_USERIMAGES_DEPS)
 	$(build-systemotherimage-target)
 
-endif # BOARD_USES_SYSTEM_OTHER
+endif # BUILDING_SYSTEM_OTHER_IMAGE
 
 
 # -----------------------------------------------------------------
 # vendor partition image
-ifdef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_VENDOR_IMAGE
 INTERNAL_VENDORIMAGE_FILES := \
     $(filter $(TARGET_OUT_VENDOR)/%,\
       $(ALL_DEFAULT_INSTALLED_MODULES)\
@@ -2607,7 +2604,7 @@
 
 # -----------------------------------------------------------------
 # product partition image
-ifdef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_IMAGE
 INTERNAL_PRODUCTIMAGE_FILES := \
     $(filter $(TARGET_OUT_PRODUCT)/%,\
       $(ALL_DEFAULT_INSTALLED_MODULES)\
@@ -2662,7 +2659,7 @@
 
 # -----------------------------------------------------------------
 # product_services partition image
-ifdef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_SERVICES_IMAGE
 INTERNAL_PRODUCT_SERVICESIMAGE_FILES := \
     $(filter $(TARGET_OUT_PRODUCT_SERVICES)/%,\
       $(ALL_DEFAULT_INSTALLED_MODULES)\
@@ -2717,7 +2714,7 @@
 
 # -----------------------------------------------------------------
 # odm partition image
-ifdef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_ODM_IMAGE
 INTERNAL_ODMIMAGE_FILES := \
     $(filter $(TARGET_OUT_ODM)/%,\
       $(ALL_DEFAULT_INSTALLED_MODULES)\
@@ -3543,33 +3540,37 @@
 	$(hide) $(foreach t,$(INSTALLED_RADIOIMAGE_TARGET),\
 	            mkdir -p $(zip_root)/RADIO; \
 	            cp $(t) $(zip_root)/RADIO/$(notdir $(t));)
+ifdef BUILDING_SYSTEM_IMAGE
 	@# Contents of the system image
 	$(hide) $(call package_files-copy-root, \
 	    $(SYSTEMIMAGE_SOURCE_DIR),$(zip_root)/SYSTEM)
+endif
+ifdef BUILDING_USERDATA_IMAGE
 	@# Contents of the data image
 	$(hide) $(call package_files-copy-root, \
 	    $(TARGET_OUT_DATA),$(zip_root)/DATA)
-ifdef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+endif
+ifdef BUILDING_VENDOR_IMAGE
 	@# Contents of the vendor image
 	$(hide) $(call package_files-copy-root, \
 	    $(TARGET_OUT_VENDOR),$(zip_root)/VENDOR)
 endif
-ifdef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_IMAGE
 	@# Contents of the product image
 	$(hide) $(call package_files-copy-root, \
 	    $(TARGET_OUT_PRODUCT),$(zip_root)/PRODUCT)
 endif
-ifdef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_SERVICES_IMAGE
 	@# Contents of the product_services image
 	$(hide) $(call package_files-copy-root, \
 	    $(TARGET_OUT_PRODUCT_SERVICES),$(zip_root)/PRODUCT_SERVICES)
 endif
-ifdef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_ODM_IMAGE
 	@# Contents of the odm image
 	$(hide) $(call package_files-copy-root, \
 	    $(TARGET_OUT_ODM),$(zip_root)/ODM)
 endif
-ifdef INSTALLED_SYSTEMOTHERIMAGE_TARGET
+ifdef BUILDING_SYSTEM_OTHER_IMAGE
 	@# Contents of the system_other image
 	$(hide) $(call package_files-copy-root, \
 	    $(TARGET_OUT_SYSTEM_OTHER),$(zip_root)/SYSTEM_OTHER)
@@ -3768,17 +3769,19 @@
 	    echo $(part) >> $(zip_root)/META/pack_radioimages.txt;)
 	@# Run fs_config on all the system, vendor, boot ramdisk,
 	@# and recovery ramdisk files in the zip, and save the output
+ifdef BUILDING_SYSTEM_IMAGE
 	$(hide) $(call fs_config,$(zip_root)/SYSTEM,system/) > $(zip_root)/META/filesystem_config.txt
-ifdef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+endif
+ifdef BUILDING_VENDOR_IMAGE
 	$(hide) $(call fs_config,$(zip_root)/VENDOR,vendor/) > $(zip_root)/META/vendor_filesystem_config.txt
 endif
-ifdef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_IMAGE
 	$(hide) $(call fs_config,$(zip_root)/PRODUCT,product/) > $(zip_root)/META/product_filesystem_config.txt
 endif
-ifdef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_PRODUCT_SERVICES_IMAGE
 	$(hide) $(call fs_config,$(zip_root)/PRODUCT_SERVICES,product_services/) > $(zip_root)/META/product_services_filesystem_config.txt
 endif
-ifdef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
+ifdef BUILDING_ODM_IMAGE
 	$(hide) $(call fs_config,$(zip_root)/ODM,odm/) > $(zip_root)/META/odm_filesystem_config.txt
 endif
 	@# ROOT always contains the files for the root under normal boot.
@@ -3794,7 +3797,7 @@
 ifneq ($(INSTALLED_RECOVERYIMAGE_TARGET),)
 	$(hide) $(call fs_config,$(zip_root)/RECOVERY/RAMDISK,) > $(zip_root)/META/recovery_filesystem_config.txt
 endif
-ifdef INSTALLED_SYSTEMOTHERIMAGE_TARGET
+ifdef BUILDING_SYSTEM_OTHER_IMAGE
 	$(hide) $(call fs_config,$(zip_root)/SYSTEM_OTHER,system/) > $(zip_root)/META/system_other_filesystem_config.txt
 endif
 	@# Metadata for compatibility verification.
diff --git a/core/config.mk b/core/config.mk
index ab9f4c3..b4fb298 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -1063,11 +1063,11 @@
 # AOSP target built without vendor image), don't build the retrofit full OTA package. Because we
 # won't be able to build meaningful super_* images for retrofitting purpose.
 ifneq (,$(filter vendor,$(BOARD_SUPER_PARTITION_PARTITION_LIST)))
-ifndef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+ifndef BUILDING_VENDOR_IMAGE
 ifndef BOARD_PREBUILT_VENDORIMAGE
 BOARD_BUILD_RETROFIT_DYNAMIC_PARTITIONS_OTA_PACKAGE :=
 endif # BOARD_PREBUILT_VENDORIMAGE
-endif # BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+endif # BUILDING_VENDOR_IMAGE
 endif # BOARD_SUPER_PARTITION_PARTITION_LIST
 
 else # PRODUCT_RETROFIT_DYNAMIC_PARTITIONS
diff --git a/core/envsetup.mk b/core/envsetup.mk
index 8150fb6..390a182 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -296,26 +296,112 @@
 endif
 
 ###########################################
+# Configure whether we're building the system image
+BUILDING_SYSTEM_IMAGE := true
+ifeq ($(PRODUCT_BUILD_SYSTEM_IMAGE),)
+  ifndef PRODUCT_USE_DYNAMIC_PARTITION_SIZE
+    ifndef BOARD_SYSTEMIMAGE_PARTITION_SIZE
+      BUILDING_SYSTEM_IMAGE :=
+    endif
+  endif
+else ifeq ($(PRODUCT_BUILD_SYSTEM_IMAGE),false)
+  BUILDING_SYSTEM_IMAGE :=
+endif
+.KATI_READONLY := BUILDING_SYSTEM_IMAGE
+
+# Are we building a system_other image
+BUILDING_SYSTEM_OTHER_IMAGE :=
+ifeq ($(PRODUCT_BUILD_SYSTEM_OTHER_IMAGE),)
+  ifdef BUILDING_SYSTEM_IMAGE
+    ifeq ($(BOARD_USES_SYSTEM_OTHER_ODEX),true)
+      BUILDING_SYSTEM_OTHER_IMAGE := true
+    endif
+  endif
+else ifeq ($(PRODUCT_BUILD_SYSTEM_OTHER_IMAGE),true)
+  BUILDING_SYSTEM_OTHER_IMAGE := true
+  ifndef BUILDING_SYSTEM_IMAGE
+    $(error PRODUCT_BUILD_SYSTEM_OTHER_IMAGE = true requires building the system image)
+  endif
+endif
+.KATI_READONLY := BUILDING_SYSTEM_OTHER_IMAGE
+
+# Are we building a cache image
+BUILDING_CACHE_IMAGE :=
+ifeq ($(PRODUCT_BUILD_CACHE_IMAGE),)
+  ifdef BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
+    BUILDING_CACHE_IMAGE := true
+  endif
+else ifeq ($(PRODUCT_BUILD_CACHE_IMAGE),true)
+  BUILDING_CACHE_IMAGE := true
+  ifndef BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE
+    $(error PRODUCT_BUILD_CACHE_IMAGE set to true, but BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE not defined)
+  endif
+endif
+.KATI_READONLY := BUILDING_CACHE_IMAGE
+
+# TODO: Add BUILDING_BOOT_IMAGE / BUILDING_RECOVERY_IMAGE
+# This gets complicated with BOARD_USES_RECOVERY_AS_BOOT, so skipping for now.
+
+# Are we building a ramdisk image
+BUILDING_RAMDISK_IMAGE := true
+ifeq ($(PRODUCT_BUILD_RAMDISK_IMAGE),)
+  # TODO: Be smarter about this. This probably only needs to happen when one of the follow is true:
+  #  BUILDING_BOOT_IMAGE
+  #  BUILDING_RECOVERY_IMAGE
+else ifeq ($(PRODUCT_BUILD_RAMDISK_IMAGE),false)
+  BUILDING_RAMDISK_IMAGE :=
+endif
+.KATI_READONLY := BUILDING_RAMDISK_IMAGE
+
+# Are we building a userdata image
+BUILDING_USERDATA_IMAGE :=
+ifeq ($(PRODUCT_BUILD_USERDATA_IMAGE),)
+  ifdef BOARD_USERDATAIMAGE_PARTITION_SIZE
+    BUILDING_USERDATA_IMAGE := true
+  endif
+else ifeq ($(PRODUCT_BUILD_USERDATA_IMAGE),true)
+  BUILDING_USERDATA_IMAGE := true
+endif
+.KATI_READONLY := BUILDING_USERDATA_IMAGE
+
+###########################################
 # Now we can substitute with the real value of TARGET_COPY_OUT_VENDOR
 ifeq ($(TARGET_COPY_OUT_VENDOR),$(_vendor_path_placeholder))
-TARGET_COPY_OUT_VENDOR := system/vendor
+  TARGET_COPY_OUT_VENDOR := system/vendor
 else ifeq ($(filter vendor system/vendor,$(TARGET_COPY_OUT_VENDOR)),)
-$(error TARGET_COPY_OUT_VENDOR must be either 'vendor' or 'system/vendor', seeing '$(TARGET_COPY_OUT_VENDOR)'.)
+  $(error TARGET_COPY_OUT_VENDOR must be either 'vendor' or 'system/vendor', seeing '$(TARGET_COPY_OUT_VENDOR)'.)
 endif
 PRODUCT_COPY_FILES := $(subst $(_vendor_path_placeholder),$(TARGET_COPY_OUT_VENDOR),$(PRODUCT_COPY_FILES))
 
 BOARD_USES_VENDORIMAGE :=
 ifdef BOARD_PREBUILT_VENDORIMAGE
-BOARD_USES_VENDORIMAGE := true
+  BOARD_USES_VENDORIMAGE := true
 endif
 ifdef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
-BOARD_USES_VENDORIMAGE := true
+  BOARD_USES_VENDORIMAGE := true
 endif
 ifeq ($(TARGET_COPY_OUT_VENDOR),vendor)
-BOARD_USES_VENDORIMAGE := true
+  BOARD_USES_VENDORIMAGE := true
 else ifdef BOARD_USES_VENDORIMAGE
-$(error TARGET_COPY_OUT_VENDOR must be set to 'vendor' to use a vendor image)
+  $(error TARGET_COPY_OUT_VENDOR must be set to 'vendor' to use a vendor image)
 endif
+.KATI_READONLY := BOARD_USES_VENDORIMAGE
+
+BUILDING_VENDOR_IMAGE :=
+ifeq ($(PRODUCT_BUILD_VENDOR_IMAGE),)
+  ifdef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+    BUILDING_VENDOR_IMAGE := true
+  endif
+else ifeq ($(PRODUCT_BUILD_VENDOR_IMAGE),true)
+  BUILDING_VENDOR_IMAGE := true
+  ifndef BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE
+    $(error PRODUCT_BUILD_VENDOR_IMAGE set to true, but BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE not defined)
+  endif
+endif
+ifdef BOARD_PREBUILT_VENDORIMAGE
+  BUILDING_VENDOR_IMAGE :=
+endif
+.KATI_READONLY := BUILDING_VENDOR_IMAGE
 
 ###########################################
 # Now we can substitute with the real value of TARGET_COPY_OUT_PRODUCT
@@ -328,61 +414,110 @@
 
 BOARD_USES_PRODUCTIMAGE :=
 ifdef BOARD_PREBUILT_PRODUCTIMAGE
-BOARD_USES_PRODUCTIMAGE := true
+  BOARD_USES_PRODUCTIMAGE := true
 endif
 ifdef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
-BOARD_USES_PRODUCTIMAGE := true
+  BOARD_USES_PRODUCTIMAGE := true
 endif
 ifeq ($(TARGET_COPY_OUT_PRODUCT),product)
-BOARD_USES_PRODUCTIMAGE := true
+  BOARD_USES_PRODUCTIMAGE := true
 else ifdef BOARD_USES_PRODUCTIMAGE
-$(error TARGET_COPY_OUT_PRODUCT must be set to 'product' to use a product image)
+  $(error TARGET_COPY_OUT_PRODUCT must be set to 'product' to use a product image)
 endif
+.KATI_READONLY := BOARD_USES_PRODUCTIMAGE
+
+BUILDING_PRODUCT_IMAGE :=
+ifeq ($(PRODUCT_BUILD_PRODUCT_IMAGE),)
+  ifdef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
+    BUILDING_PRODUCT_IMAGE := true
+  endif
+else ifeq ($(PRODUCT_BUILD_PRODUCT_IMAGE),true)
+  BUILDING_PRODUCT_IMAGE := true
+  ifndef BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE
+    $(error PRODUCT_BUILD_PRODUCT_IMAGE set to true, but BOARD_PRODUCTIMAGE_FILE_SYSTEM_TYPE not defined)
+  endif
+endif
+ifdef BOARD_PREBUILT_PRODUCTIMAGE
+  BUILDING_PRODUCT_IMAGE :=
+endif
+.KATI_READONLY := BUILDING_PRODUCT_IMAGE
 
 ###########################################
 # Now we can substitute with the real value of TARGET_COPY_OUT_PRODUCT_SERVICES
 ifeq ($(TARGET_COPY_OUT_PRODUCT_SERVICES),$(_product_services_path_placeholder))
-TARGET_COPY_OUT_PRODUCT_SERVICES := system/product_services
+  TARGET_COPY_OUT_PRODUCT_SERVICES := system/product_services
 else ifeq ($(filter product_services system/product_services,$(TARGET_COPY_OUT_PRODUCT_SERVICES)),)
-$(error TARGET_COPY_OUT_PRODUCT_SERVICES must be either 'product_services' or 'system/product_services', seeing '$(TARGET_COPY_OUT_PRODUCT_SERVICES)'.)
+  $(error TARGET_COPY_OUT_PRODUCT_SERVICES must be either 'product_services' or 'system/product_services', seeing '$(TARGET_COPY_OUT_PRODUCT_SERVICES)'.)
 endif
 PRODUCT_COPY_FILES := $(subst $(_product_services_path_placeholder),$(TARGET_COPY_OUT_PRODUCT_SERVICES),$(PRODUCT_COPY_FILES))
 
 BOARD_USES_PRODUCT_SERVICESIMAGE :=
 ifdef BOARD_PREBUILT_PRODUCT_SERVICESIMAGE
-BOARD_USES_PRODUCT_SERVICESIMAGE := true
+  BOARD_USES_PRODUCT_SERVICESIMAGE := true
 endif
 ifdef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
-BOARD_USES_PRODUCT_SERVICESIMAGE := true
+  BOARD_USES_PRODUCT_SERVICESIMAGE := true
 endif
 ifeq ($(TARGET_COPY_OUT_PRODUCT_SERVICES),product_services)
-BOARD_USES_PRODUCT_SERVICESIMAGE := true
+  BOARD_USES_PRODUCT_SERVICESIMAGE := true
 else ifdef BOARD_USES_PRODUCT_SERVICESIMAGE
-$(error TARGET_COPY_OUT_PRODUCT_SERVICES must be set to 'product_services' to use a product_services image)
+  $(error TARGET_COPY_OUT_PRODUCT_SERVICES must be set to 'product_services' to use a product_services image)
 endif
 
+BUILDING_PRODUCT_SERVICES_IMAGE :=
+ifeq ($(PRODUCT_SERVICES_BUILD_PRODUCT_SERVICES_IMAGE),)
+  ifdef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
+    BUILDING_PRODUCT_SERVICES_IMAGE := true
+  endif
+else ifeq ($(PRODUCT_BUILD_PRODUCT_SERVICES_IMAGE),true)
+  BUILDING_PRODUCT_SERVICES_IMAGE := true
+  ifndef BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE
+    $(error PRODUCT_BUILD_PRODUCT_SERVICES_IMAGE set to true, but BOARD_PRODUCT_SERVICESIMAGE_FILE_SYSTEM_TYPE not defined)
+  endif
+endif
+ifdef BOARD_PREBUILT_PRODUCT_SERVICESIMAGE
+  BUILDING_PRODUCT_SERVICES_IMAGE :=
+endif
+.KATI_READONLY := BUILDING_PRODUCT_SERVICES_IMAGE
+
 ###########################################
 # Now we can substitute with the real value of TARGET_COPY_OUT_ODM
 ifeq ($(TARGET_COPY_OUT_ODM),$(_odm_path_placeholder))
-TARGET_COPY_OUT_ODM := vendor/odm
+  TARGET_COPY_OUT_ODM := vendor/odm
 else ifeq ($(filter odm vendor/odm,$(TARGET_COPY_OUT_ODM)),)
-$(error TARGET_COPY_OUT_ODM must be either 'odm' or 'vendor/odm', seeing '$(TARGET_COPY_OUT_ODM)'.)
+  $(error TARGET_COPY_OUT_ODM must be either 'odm' or 'vendor/odm', seeing '$(TARGET_COPY_OUT_ODM)'.)
 endif
 PRODUCT_COPY_FILES := $(subst $(_odm_path_placeholder),$(TARGET_COPY_OUT_ODM),$(PRODUCT_COPY_FILES))
 
 BOARD_USES_ODMIMAGE :=
 ifdef BOARD_PREBUILT_ODMIMAGE
-BOARD_USES_ODMIMAGE := true
+  BOARD_USES_ODMIMAGE := true
 endif
 ifdef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
-BOARD_USES_ODMIMAGE := true
+  BOARD_USES_ODMIMAGE := true
 endif
 ifeq ($(TARGET_COPY_OUT_ODM),odm)
-BOARD_USES_ODMIMAGE := true
+  BOARD_USES_ODMIMAGE := true
 else ifdef BOARD_USES_ODMIMAGE
-$(error TARGET_COPY_OUT_ODM must be set to 'odm' to use an odm image)
+  $(error TARGET_COPY_OUT_ODM must be set to 'odm' to use an odm image)
 endif
 
+BUILDING_ODM_IMAGE :=
+ifeq ($(ODM_BUILD_ODM_IMAGE),)
+  ifdef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
+    BUILDING_ODM_IMAGE := true
+  endif
+else ifeq ($(PRODUCT_BUILD_ODM_IMAGE),true)
+  BUILDING_ODM_IMAGE := true
+  ifndef BOARD_ODMIMAGE_FILE_SYSTEM_TYPE
+    $(error PRODUCT_BUILD_ODM_IMAGE set to true, but BOARD_ODMIMAGE_FILE_SYSTEM_TYPE not defined)
+  endif
+endif
+ifdef BOARD_PREBUILT_ODMIMAGE
+  BUILDING_ODM_IMAGE :=
+endif
+.KATI_READONLY := BUILDING_ODM_IMAGE
+
 ###########################################
 # Ensure that only TARGET_RECOVERY_UPDATER_LIBS *or* AB_OTA_UPDATER is set.
 TARGET_RECOVERY_UPDATER_LIBS ?=
diff --git a/core/product.mk b/core/product.mk
index 2d7ace2..f52426a 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -216,6 +216,15 @@
     PRODUCT_OTA_ENFORCE_VINTF_KERNEL_REQUIREMENTS \
     PRODUCT_XOM_EXCLUDE_PATHS \
     PRODUCT_MANIFEST_PACKAGE_NAME_OVERRIDES \
+    PRODUCT_BUILD_SYSTEM_IMAGE \
+    PRODUCT_BUILD_SYSTEM_OTHER_IMAGE \
+    PRODUCT_BUILD_VENDOR_IMAGE \
+    PRODUCT_BUILD_PRODUCT_IMAGE \
+    PRODUCT_BUILD_PRODUCT_SERVICES_IMAGE \
+    PRODUCT_BUILD_ODM_IMAGE \
+    PRODUCT_BUILD_CACHE_IMAGE \
+    PRODUCT_BUILD_RAMDISK_IMAGE \
+    PRODUCT_BUILD_USERDATA_IMAGE \
 
 define dump-product
 $(info ==== $(1) ====)\
diff --git a/core/product_config.mk b/core/product_config.mk
index c58405c..c4bbdc8 100644
--- a/core/product_config.mk
+++ b/core/product_config.mk
@@ -566,3 +566,27 @@
 PRODUCT_MANIFEST_PACKAGE_NAME_OVERRIDES := \
     $(strip $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_MANIFEST_PACKAGE_NAME_OVERRIDES))
 .KATI_READONLY := PRODUCT_MANIFEST_PACKAGE_NAME_OVERRIDES
+
+# Macro to use below. $(1) is the name of the partition
+define product-build-image-config
+PRODUCT_BUILD_$(1)_IMAGE := $$(firstword $$(strip $$(PRODUCTS.$$(INTERNAL_PRODUCT).PRODUCT_BUILD_$(1)_IMAGE)))
+.KATI_READONLY := PRODUCT_BUILD_$(1)_IMAGE
+ifneq ($$(filter-out true false,$$(PRODUCT_BUILD_$(1)_IMAGE)),)
+    $$(error Invalid PRODUCT_BUILD_$(1)_IMAGE: $$(PRODUCT_BUILD_$(1)_IMAGE) -- true false and empty are supported)
+endif
+endef
+
+# Copy and check the value of each PRODUCT_BUILD_*_IMAGE variable
+$(foreach image, \
+    SYSTEM \
+    SYSTEM_OTHER \
+    VENDOR \
+    PRODUCT \
+    PRODUCT_SERVICES \
+    ODM \
+    CACHE \
+    RAMDISK \
+    USERDATA, \
+  $(eval $(call product-build-image-config,$(image))))
+
+product-build-image-config :=