diff --git a/core/config.mk b/core/config.mk
index 075af49..58cf42c 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -45,6 +45,9 @@
 backslash := \a
 backslash := $(patsubst %a,%,$(backslash))
 
+# Prevent accidentally changing these variables
+.KATI_READONLY := SHELL empty space comma newline pound backslash
+
 # this turns off the suffix rules built into make
 .SUFFIXES:
 
@@ -58,6 +61,10 @@
 # If a rule fails, delete $@.
 .DELETE_ON_ERROR:
 
+# Mark variables that should be coming as environment variables from soong_ui
+# as readonly
+.KATI_READONLY := OUT_DIR TMPDIR BUILD_DATETIME_FILE
+
 # Mark variables deprecated/obsolete
 CHANGES_URL := https://android.googlesource.com/platform/build/+/master/Changes.md
 $(KATI_obsolete_var PATH,Do not use PATH directly. See $(CHANGES_URL)#PATH)
diff --git a/core/envsetup.mk b/core/envsetup.mk
index dc4bc3b..a3e78e7 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -374,28 +374,22 @@
 # ---------------------------------------------------------------
 # figure out the output directories
 
-ifeq (,$(strip $(OUT_DIR)))
-ifeq (,$(strip $(OUT_DIR_COMMON_BASE)))
-OUT_DIR := $(TOPDIR)out
-else
-OUT_DIR := $(OUT_DIR_COMMON_BASE)/$(notdir $(PWD))
-endif
-endif
-
 SOONG_OUT_DIR := $(OUT_DIR)/soong
 
 TARGET_OUT_ROOT := $(OUT_DIR)/target
 
 HOST_OUT_ROOT := $(OUT_DIR)/host
 
+.KATI_READONLY := SOONG_OUT_DIR TARGET_OUT_ROOT HOST_OUT_ROOT
+
 # We want to avoid two host bin directories in multilib build.
 HOST_OUT := $(HOST_OUT_ROOT)/$(HOST_OS)-$(HOST_PREBUILT_ARCH)
 SOONG_HOST_OUT := $(SOONG_OUT_DIR)/host/$(HOST_OS)-$(HOST_PREBUILT_ARCH)
-# TODO: remove
-BUILD_OUT := $(HOST_OUT)
 
 HOST_CROSS_OUT := $(HOST_OUT_ROOT)/windows-$(HOST_PREBUILT_ARCH)
 
+.KATI_READONLY := HOST_OUT SOONG_HOST_OUT HOST_CROSS_OUT
+
 TARGET_PRODUCT_OUT_ROOT := $(TARGET_OUT_ROOT)/product
 
 TARGET_COMMON_OUT_ROOT := $(TARGET_OUT_ROOT)/common
@@ -403,11 +397,17 @@
 
 PRODUCT_OUT := $(TARGET_PRODUCT_OUT_ROOT)/$(TARGET_DEVICE)
 
+.KATI_READONLY := TARGET_PRODUCT_OUT_ROOT TARGET_COMMON_OUT_ROOT HOST_COMMON_OUT_ROOT PRODUCT_OUT
+
 OUT_DOCS := $(TARGET_COMMON_OUT_ROOT)/docs
 OUT_NDK_DOCS := $(TARGET_COMMON_OUT_ROOT)/ndk-docs
+.KATI_READONLY := OUT_DOCS OUT_NDK_DOCS
 
-BUILD_OUT_EXECUTABLES := $(BUILD_OUT)/bin
+$(call KATI_obsolete,BUILD_OUT,Use HOST_OUT instead)
+
+BUILD_OUT_EXECUTABLES := $(HOST_OUT)/bin
 SOONG_HOST_OUT_EXECUTABLES := $(SOONG_HOST_OUT)/bin
+.KATI_READONLY := BUILD_OUT_EXECUTABLES SOONG_HOST_OUT_EXECUTABLES
 
 HOST_OUT_EXECUTABLES := $(HOST_OUT)/bin
 HOST_OUT_SHARED_LIBRARIES := $(HOST_OUT)/lib64
@@ -417,18 +417,39 @@
 HOST_OUT_NATIVE_TESTS := $(HOST_OUT)/nativetest64
 HOST_OUT_COVERAGE := $(HOST_OUT)/coverage
 HOST_OUT_TESTCASES := $(HOST_OUT)/testcases
+.KATI_READONLY := \
+  HOST_OUT_EXECUTABLES \
+  HOST_OUT_SHARED_LIBRARIES \
+  HOST_OUT_RENDERSCRIPT_BITCODE \
+  HOST_OUT_JAVA_LIBRARIES \
+  HOST_OUT_SDK_ADDON \
+  HOST_OUT_NATIVE_TESTS \
+  HOST_OUT_COVERAGE \
+  HOST_OUT_TESTCASES
 
 HOST_CROSS_OUT_EXECUTABLES := $(HOST_CROSS_OUT)/bin
 HOST_CROSS_OUT_SHARED_LIBRARIES := $(HOST_CROSS_OUT)/lib
 HOST_CROSS_OUT_NATIVE_TESTS := $(HOST_CROSS_OUT)/nativetest
 HOST_CROSS_OUT_COVERAGE := $(HOST_CROSS_OUT)/coverage
 HOST_CROSS_OUT_TESTCASES := $(HOST_CROSS_OUT)/testcases
+.KATI_READONLY := \
+  HOST_CROSS_OUT_EXECUTABLES \
+  HOST_CROSS_OUT_SHARED_LIBRARIES \
+  HOST_CROSS_OUT_NATIVE_TESTS \
+  HOST_CROSS_OUT_COVERAGE \
+  HOST_CROSS_OUT_TESTCASES
 
 HOST_OUT_INTERMEDIATES := $(HOST_OUT)/obj
 HOST_OUT_INTERMEDIATE_LIBRARIES := $(HOST_OUT_INTERMEDIATES)/lib
 HOST_OUT_NOTICE_FILES := $(HOST_OUT_INTERMEDIATES)/NOTICE_FILES
 HOST_OUT_COMMON_INTERMEDIATES := $(HOST_COMMON_OUT_ROOT)/obj
 HOST_OUT_FAKE := $(HOST_OUT)/fake_packages
+.KATI_READONLY := \
+  HOST_OUT_INTERMEDIATES \
+  HOST_OUT_INTERMEDIATE_LIBRARIES \
+  HOST_OUT_NOTICE_FILES \
+  HOST_OUT_COMMON_INTERMEDIATES \
+  HOST_OUT_FAKE
 
 # Nano environment config
 include $(BUILD_SYSTEM)/aux_config.mk
@@ -436,13 +457,22 @@
 HOST_CROSS_OUT_INTERMEDIATES := $(HOST_CROSS_OUT)/obj
 HOST_CROSS_OUT_INTERMEDIATE_LIBRARIES := $(HOST_CROSS_OUT_INTERMEDIATES)/lib
 HOST_CROSS_OUT_NOTICE_FILES := $(HOST_CROSS_OUT_INTERMEDIATES)/NOTICE_FILES
+.KATI_READONLY := \
+  HOST_CROSS_OUT_INTERMEDIATES \
+  HOST_CROSS_OUT_INTERMEDIATE_LIBRARIES \
+  HOST_CROSS_OUT_NOTICE_FILES
 
 HOST_OUT_GEN := $(HOST_OUT)/gen
 HOST_OUT_COMMON_GEN := $(HOST_COMMON_OUT_ROOT)/gen
+.KATI_READONLY := \
+  HOST_OUT_GEN \
+  HOST_OUT_COMMON_GEN
 
 HOST_CROSS_OUT_GEN := $(HOST_CROSS_OUT)/gen
+.KATI_READONLY := HOST_CROSS_OUT_GEN
 
 HOST_OUT_TEST_CONFIG := $(HOST_OUT)/test_config
+.KATI_READONLY := HOST_OUT_TEST_CONFIG
 
 # Out for HOST_2ND_ARCH
 HOST_2ND_ARCH_VAR_PREFIX := 2ND_
@@ -454,10 +484,21 @@
 $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_JAVA_LIBRARIES := $(HOST_OUT_JAVA_LIBRARIES)
 $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_NATIVE_TESTS := $(HOST_OUT)/nativetest
 $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_TESTCASES := $(HOST_OUT_TESTCASES)
+.KATI_READONLY := \
+  HOST_2ND_ARCH_VAR_PREFIX \
+  HOST_2ND_ARCH_MODULE_SUFFIX \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATES \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_INTERMEDIATE_LIBRARIES \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_SHARED_LIBRARIES \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_EXECUTABLES \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_JAVA_LIBRARIES \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_NATIVE_TESTS \
+  $(HOST_2ND_ARCH_VAR_PREFIX)HOST_OUT_TESTCASES
 
 # The default host library path.
 # It always points to the path where we build libraries in the default bitness.
 HOST_LIBRARY_PATH := $(HOST_OUT_SHARED_LIBRARIES)
+.KATI_READONLY := HOST_LIBRARY_PATH
 
 # Out for HOST_CROSS_2ND_ARCH
 HOST_CROSS_2ND_ARCH_VAR_PREFIX := 2ND_
@@ -467,6 +508,14 @@
 $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_SHARED_LIBRARIES := $(HOST_CROSS_OUT)/lib64
 $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_EXECUTABLES := $(HOST_CROSS_OUT_EXECUTABLES)
 $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_NATIVE_TESTS := $(HOST_CROSS_OUT)/nativetest64
+.KATI_READONLY := \
+  HOST_CROSS_2ND_ARCH_VAR_PREFIX \
+  HOST_CROSS_2ND_ARCH_MODULE_SUFFIX \
+  $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_INTERMEDIATES \
+  $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_INTERMEDIATE_LIBRARIES \
+  $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_SHARED_LIBRARIES \
+  $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_EXECUTABLES \
+  $(HOST_CROSS_2ND_ARCH_VAR_PREFIX)HOST_CROSS_OUT_NATIVE_TESTS
 
 ifneq ($(filter address,$(SANITIZE_TARGET)),)
   TARGET_OUT_INTERMEDIATES := $(PRODUCT_OUT)/obj_asan
@@ -475,17 +524,21 @@
 endif
 TARGET_OUT_HEADERS := $(TARGET_OUT_INTERMEDIATES)/include
 TARGET_OUT_INTERMEDIATE_LIBRARIES := $(TARGET_OUT_INTERMEDIATES)/lib
+.KATI_READONLY := TARGET_OUT_INTERMEDIATES TARGET_OUT_HEADERS TARGET_OUT_INTERMEDIATE_LIBRARIES
 
 ifneq ($(filter address,$(SANITIZE_TARGET)),)
   TARGET_OUT_COMMON_INTERMEDIATES := $(TARGET_COMMON_OUT_ROOT)/obj_asan
 else
   TARGET_OUT_COMMON_INTERMEDIATES := $(TARGET_COMMON_OUT_ROOT)/obj
 endif
+.KATI_READONLY := TARGET_OUT_COMMON_INTERMEDIATES
 
 TARGET_OUT_GEN := $(PRODUCT_OUT)/gen
 TARGET_OUT_COMMON_GEN := $(TARGET_COMMON_OUT_ROOT)/gen
+.KATI_READONLY := TARGET_OUT_GEN TARGET_OUT_COMMON_GEN
 
 TARGET_OUT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_SYSTEM)
+.KATI_READONLY := TARGET_OUT
 ifneq ($(filter address,$(SANITIZE_TARGET)),)
 target_out_shared_libraries_base := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ASAN)/system
 ifeq ($(SANITIZE_LITE),true)
@@ -520,6 +573,21 @@
 TARGET_OUT_FAKE := $(PRODUCT_OUT)/fake_packages
 TARGET_OUT_TESTCASES := $(PRODUCT_OUT)/testcases
 TARGET_OUT_TEST_CONFIG := $(PRODUCT_OUT)/test_config
+.KATI_READONLY := \
+  TARGET_OUT_EXECUTABLES \
+  TARGET_OUT_OPTIONAL_EXECUTABLES \
+  TARGET_OUT_SHARED_LIBRARIES \
+  TARGET_OUT_RENDERSCRIPT_BITCODE \
+  TARGET_OUT_JAVA_LIBRARIES \
+  TARGET_OUT_APPS \
+  TARGET_OUT_APPS_PRIVILEGED \
+  TARGET_OUT_KEYLAYOUT \
+  TARGET_OUT_KEYCHARS \
+  TARGET_OUT_ETC \
+  TARGET_OUT_NOTICE_FILES \
+  TARGET_OUT_FAKE \
+  TARGET_OUT_TESTCASES \
+  TARGET_OUT_TEST_CONFIG
 
 ifeq ($(SANITIZE_LITE),true)
 # When using SANITIZE_LITE, APKs must not be packaged with sanitized libraries, as they will not
@@ -528,6 +596,7 @@
 else
 TARGET_OUT_SYSTEM_OTHER := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_SYSTEM_OTHER)
 endif
+.KATI_READONLY := TARGET_OUT_SYSTEM_OTHER
 
 # Out for TARGET_2ND_ARCH
 TARGET_2ND_ARCH_VAR_PREFIX := $(HOST_2ND_ARCH_VAR_PREFIX)
@@ -537,6 +606,7 @@
 else
 TARGET_2ND_ARCH_MODULE_SUFFIX := $(HOST_2ND_ARCH_MODULE_SUFFIX)
 endif
+.KATI_READONLY := TARGET_2ND_ARCH_VAR_PREFIX TARGET_2ND_ARCH_MODULE_SUFFIX
 
 ifneq ($(filter address,$(SANITIZE_TARGET)),)
   $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_INTERMEDIATES := $(PRODUCT_OUT)/obj_$(TARGET_2ND_ARCH)_asan
@@ -554,6 +624,15 @@
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_APPS := $(TARGET_OUT_APPS)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_APPS_PRIVILEGED := $(TARGET_OUT_APPS_PRIVILEGED)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_TESTCASES := $(TARGET_OUT_TESTCASES)
+.KATI_READONLY := \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_INTERMEDIATES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_INTERMEDIATE_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_SHARED_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_RENDERSCRIPT_BITCODE \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_EXECUTABLES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_APPS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_APPS_PRIVILEGED \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_TESTCASES
 
 TARGET_OUT_DATA := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_DATA)
 TARGET_OUT_DATA_EXECUTABLES := $(TARGET_OUT_EXECUTABLES)
@@ -575,6 +654,20 @@
 TARGET_OUT_VENDOR_METRIC_TESTS := $(TARGET_OUT_DATA)/benchmarktest$(TARGET_VENDOR_TEST_SUFFIX)
 endif
 TARGET_OUT_DATA_FAKE := $(TARGET_OUT_DATA)/fake_packages
+.KATI_READONLY := \
+  TARGET_OUT_DATA \
+  TARGET_OUT_DATA_EXECUTABLES \
+  TARGET_OUT_DATA_SHARED_LIBRARIES \
+  TARGET_OUT_DATA_JAVA_LIBRARIES \
+  TARGET_OUT_DATA_APPS \
+  TARGET_OUT_DATA_KEYLAYOUT \
+  TARGET_OUT_DATA_KEYCHARS \
+  TARGET_OUT_DATA_ETC \
+  TARGET_OUT_DATA_NATIVE_TESTS \
+  TARGET_OUT_DATA_METRIC_TESTS \
+  TARGET_OUT_VENDOR_NATIVE_TESTS \
+  TARGET_OUT_VENDOR_METRIC_TESTS \
+  TARGET_OUT_DATA_FAKE
 
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_EXECUTABLES := $(TARGET_OUT_DATA_EXECUTABLES)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_SHARED_LIBRARIES := $($(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_SHARED_LIBRARIES)
@@ -590,10 +683,20 @@
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_NATIVE_TESTS := $(TARGET_OUT_DATA)/nativetest$(TARGET_VENDOR_TEST_SUFFIX)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_METRIC_TESTS := $(TARGET_OUT_DATA)/benchmarktest$(TARGET_VENDOR_TEST_SUFFIX)
 endif
+.KATI_READONLY := \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_EXECUTABLES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_SHARED_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_APPS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_NATIVE_TESTS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_DATA_METRIC_TESTS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_NATIVE_TESTS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_METRIC_TESTS \
 
 TARGET_OUT_CACHE := $(PRODUCT_OUT)/cache
+.KATI_READONLY := TARGET_OUT_CACHE
 
 TARGET_OUT_VENDOR := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_VENDOR)
+.KATI_READONLY := TARGET_OUT_VENDOR
 ifneq ($(filter address,$(SANITIZE_TARGET)),)
 target_out_vendor_shared_libraries_base := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ASAN)/vendor
 ifeq ($(SANITIZE_LITE),true)
@@ -620,6 +723,15 @@
 TARGET_OUT_VENDOR_APPS := $(target_out_vendor_app_base)/app
 TARGET_OUT_VENDOR_APPS_PRIVILEGED := $(target_out_vendor_app_base)/priv-app
 TARGET_OUT_VENDOR_ETC := $(TARGET_OUT_VENDOR)/etc
+.KATI_READONLY := \
+  TARGET_OUT_VENDOR_EXECUTABLES \
+  TARGET_OUT_VENDOR_OPTIONAL_EXECUTABLES \
+  TARGET_OUT_VENDOR_SHARED_LIBRARIES \
+  TARGET_OUT_VENDOR_RENDERSCRIPT_BITCODE \
+  TARGET_OUT_VENDOR_JAVA_LIBRARIES \
+  TARGET_OUT_VENDOR_APPS \
+  TARGET_OUT_VENDOR_APPS_PRIVILEGED \
+  TARGET_OUT_VENDOR_ETC
 
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_EXECUTABLES := $(TARGET_OUT_VENDOR_EXECUTABLES)
 ifeq ($(TARGET_TRANSLATE_2ND_ARCH),true)
@@ -630,6 +742,12 @@
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_RENDERSCRIPT_BITCODE := $($(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_SHARED_LIBRARIES)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_APPS := $(TARGET_OUT_VENDOR_APPS)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_APPS_PRIVILEGED := $(TARGET_OUT_VENDOR_APPS_PRIVILEGED)
+.KATI_READONLY := \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_EXECUTABLES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_SHARED_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_RENDERSCRIPT_BITCODE \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_APPS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_VENDOR_APPS_PRIVILEGED
 
 TARGET_OUT_OEM := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_OEM)
 TARGET_OUT_OEM_EXECUTABLES := $(TARGET_OUT_OEM)/bin
@@ -642,6 +760,12 @@
 # TARGET_OUT_OEM_JAVA_LIBRARIES:= $(TARGET_OUT_OEM)/framework
 TARGET_OUT_OEM_APPS := $(TARGET_OUT_OEM)/app
 TARGET_OUT_OEM_ETC := $(TARGET_OUT_OEM)/etc
+.KATI_READONLY := \
+  TARGET_OUT_OEM \
+  TARGET_OUT_OEM_EXECUTABLES \
+  TARGET_OUT_OEM_SHARED_LIBRARIES \
+  TARGET_OUT_OEM_APPS \
+  TARGET_OUT_OEM_ETC
 
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_OEM_EXECUTABLES := $(TARGET_OUT_OEM_EXECUTABLES)
 ifeq ($(TARGET_TRANSLATE_2ND_ARCH),true)
@@ -650,6 +774,10 @@
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_OEM_SHARED_LIBRARIES := $(TARGET_OUT_OEM)/lib
 endif
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_OEM_APPS := $(TARGET_OUT_OEM_APPS)
+.KATI_READONLY := \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_OEM_EXECUTABLES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_OEM_SHARED_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_OEM_APPS \
 
 TARGET_OUT_ODM := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ODM)
 TARGET_OUT_ODM_EXECUTABLES := $(TARGET_OUT_ODM)/bin
@@ -660,6 +788,12 @@
 endif
 TARGET_OUT_ODM_APPS := $(TARGET_OUT_ODM)/app
 TARGET_OUT_ODM_ETC := $(TARGET_OUT_ODM)/etc
+.KATI_READONLY := \
+  TARGET_OUT_ODM \
+  TARGET_OUT_ODM_EXECUTABLES \
+  TARGET_OUT_ODM_SHARED_LIBRARIES \
+  TARGET_OUT_ODM_APPS \
+  TARGET_OUT_ODM_ETC
 
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_ODM_EXECUTABLES := $(TARGET_OUT_ODM_EXECUTABLES)
 ifeq ($(TARGET_TRANSLATE_2ND_ARCH),true)
@@ -668,8 +802,13 @@
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_ODM_SHARED_LIBRARIES := $(TARGET_OUT_ODM)/lib
 endif
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_ODM_APPS := $(TARGET_OUT_ODM_APPS)
+.KATI_READONLY := \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_ODM_EXECUTABLES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_ODM_SHARED_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_ODM_APPS
 
 TARGET_OUT_PRODUCT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_PRODUCT)
+.KATI_READONLY := TARGET_OUT_PRODUCT
 ifneq ($(filter address,$(SANITIZE_TARGET)),)
 target_out_product_shared_libraries_base := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ASAN)/product
 ifeq ($(SANITIZE_LITE),true)
@@ -689,10 +828,16 @@
 else
 TARGET_OUT_PRODUCT_SHARED_LIBRARIES := $(target_out_product_shared_libraries_base)/lib
 endif
-TARGET_OUT_PRODUCT_JAVA_LIBRARIES:= $(TARGET_OUT_PRODUCT)/framework
+TARGET_OUT_PRODUCT_JAVA_LIBRARIES := $(TARGET_OUT_PRODUCT)/framework
 TARGET_OUT_PRODUCT_APPS := $(target_out_product_app_base)/app
 TARGET_OUT_PRODUCT_APPS_PRIVILEGED := $(target_out_product_app_base)/priv-app
 TARGET_OUT_PRODUCT_ETC := $(TARGET_OUT_PRODUCT)/etc
+.KATI_READONLY := \
+  TARGET_OUT_PRODUCT_SHARED_LIBRARIES \
+  TARGET_OUT_PRODUCT_JAVA_LIBRARIES \
+  TARGET_OUT_PRODUCT_APPS \
+  TARGET_OUT_PRODUCT_APPS_PRIVILEGED \
+  TARGET_OUT_PRODUCT_ETC
 
 ifeq ($(TARGET_TRANSLATE_2ND_ARCH),true)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_PRODUCT_SHARED_LIBRARIES := $(target_out_product_shared_libraries_base)/lib/$(TARGET_2ND_ARCH)
@@ -701,8 +846,13 @@
 endif
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_PRODUCT_APPS := $(TARGET_OUT_PRODUCT_APPS)
 $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_PRODUCT_APPS_PRIVILEGED := $(TARGET_OUT_PRODUCT_APPS_PRIVILEGED)
+.KATI_READONLY := \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_PRODUCT_SHARED_LIBRARIES \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_PRODUCT_APPS \
+  $(TARGET_2ND_ARCH_VAR_PREFIX)TARGET_OUT_PRODUCT_APPS_PRIVILEGED
 
 TARGET_OUT_BREAKPAD := $(PRODUCT_OUT)/breakpad
+.KATI_READONLY := TARGET_OUT_BREAKPAD
 
 TARGET_OUT_UNSTRIPPED := $(PRODUCT_OUT)/symbols
 TARGET_OUT_EXECUTABLES_UNSTRIPPED := $(TARGET_OUT_UNSTRIPPED)/system/bin
@@ -712,31 +862,60 @@
 TARGET_ROOT_OUT_SBIN_UNSTRIPPED := $(TARGET_OUT_UNSTRIPPED)/sbin
 TARGET_ROOT_OUT_BIN_UNSTRIPPED := $(TARGET_OUT_UNSTRIPPED)/bin
 TARGET_OUT_COVERAGE := $(PRODUCT_OUT)/coverage
+.KATI_READONLY := \
+  TARGET_OUT_UNSTRIPPED \
+  TARGET_OUT_EXECUTABLES_UNSTRIPPED \
+  TARGET_OUT_SHARED_LIBRARIES_UNSTRIPPED \
+  TARGET_OUT_VENDOR_SHARED_LIBRARIES_UNSTRIPPED \
+  TARGET_ROOT_OUT_UNSTRIPPED \
+  TARGET_ROOT_OUT_SBIN_UNSTRIPPED \
+  TARGET_ROOT_OUT_BIN_UNSTRIPPED \
+  TARGET_OUT_COVERAGE
 
 TARGET_ROOT_OUT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_ROOT)
 TARGET_ROOT_OUT_BIN := $(TARGET_ROOT_OUT)/bin
 TARGET_ROOT_OUT_SBIN := $(TARGET_ROOT_OUT)/sbin
 TARGET_ROOT_OUT_ETC := $(TARGET_ROOT_OUT)/etc
 TARGET_ROOT_OUT_USR := $(TARGET_ROOT_OUT)/usr
+.KATI_READONLY := \
+  TARGET_ROOT_OUT \
+  TARGET_ROOT_OUT_BIN \
+  TARGET_ROOT_OUT_SBIN \
+  TARGET_ROOT_OUT_ETC \
+  TARGET_ROOT_OUT_USR
 
 TARGET_RECOVERY_OUT := $(PRODUCT_OUT)/$(TARGET_COPY_OUT_RECOVERY)
 TARGET_RECOVERY_ROOT_OUT := $(TARGET_RECOVERY_OUT)/root
+.KATI_READONLY := \
+  TARGET_RECOVERY_OUT \
+  TARGET_RECOVERY_ROOT_OUT
 
 TARGET_SYSLOADER_OUT := $(PRODUCT_OUT)/sysloader
 TARGET_SYSLOADER_ROOT_OUT := $(TARGET_SYSLOADER_OUT)/root
 TARGET_SYSLOADER_SYSTEM_OUT := $(TARGET_SYSLOADER_OUT)/root/system
+.KATI_READONLY := \
+  TARGET_SYSLOADER_OUT \
+  TARGET_SYSLOADER_ROOT_OUT \
+  TARGET_SYSLOADER_SYSTEM_OUT
 
 TARGET_INSTALLER_OUT := $(PRODUCT_OUT)/installer
 TARGET_INSTALLER_DATA_OUT := $(TARGET_INSTALLER_OUT)/data
 TARGET_INSTALLER_ROOT_OUT := $(TARGET_INSTALLER_OUT)/root
 TARGET_INSTALLER_SYSTEM_OUT := $(TARGET_INSTALLER_OUT)/root/system
+.KATI_READONLY := \
+  TARGET_INSTALLER_OUT \
+  TARGET_INSTALLER_DATA_OUT \
+  TARGET_INSTALLER_ROOT_OUT \
+  TARGET_INSTALLER_SYSTEM_OUT
 
 COMMON_MODULE_CLASSES := TARGET-NOTICE_FILES HOST-NOTICE_FILES HOST-JAVA_LIBRARIES
 PER_ARCH_MODULE_CLASSES := SHARED_LIBRARIES STATIC_LIBRARIES EXECUTABLES GYP RENDERSCRIPT_BITCODE NATIVE_TESTS HEADER_LIBRARIES
+.KATI_READONLY := COMMON_MODULE_CLASSES PER_ARCH_MODULE_CLASSES
 
 ifeq (,$(strip $(DIST_DIR)))
   DIST_DIR := $(OUT_DIR)/dist
 endif
+.KATI_READONLY := DIST_DIR
 
 ifeq ($(CALLED_FROM_SETUP),true)
 PRINT_BUILD_CONFIG ?= true