diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index 317f5c4..e8cad7d 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -4,3 +4,4 @@
 
 [Hook Scripts]
 do_not_use_DO_NOT_MERGE = ${REPO_ROOT}/build/soong/scripts/check_do_not_merge.sh ${PREUPLOAD_COMMIT}
+aosp_hook = ${REPO_ROOT}/frameworks/base/tools/aosp/aosp_sha.sh ${PREUPLOAD_COMMIT} "."
diff --git a/aconfig/codegen/cc_aconfig_library.go b/aconfig/codegen/cc_aconfig_library.go
index f3e9599..ec0a6b6 100644
--- a/aconfig/codegen/cc_aconfig_library.go
+++ b/aconfig/codegen/cc_aconfig_library.go
@@ -88,10 +88,13 @@
 	if mode != "force-read-only" {
 		deps.SharedLibs = append(deps.SharedLibs, baseLibDep)
 
-		deps.SharedLibs = append(deps.SharedLibs, libAconfigStorageReadApiCcDep)
-		deps.SharedLibs = append(deps.SharedLibs, libLogDep)
-		deps.SharedLibs = append(deps.SharedLibs, libBaseDep)
 	}
+
+	// TODO: after storage migration is over, don't add these in force-read-only-mode.
+	deps.SharedLibs = append(deps.SharedLibs, libAconfigStorageReadApiCcDep)
+	deps.SharedLibs = append(deps.SharedLibs, libBaseDep)
+	deps.SharedLibs = append(deps.SharedLibs, libLogDep)
+
 	// TODO: It'd be really nice if we could reexport this library and not make everyone do it.
 
 	return deps
diff --git a/aconfig/codegen/cc_aconfig_library_test.go b/aconfig/codegen/cc_aconfig_library_test.go
index 2e7fdc2..cf9ffbd 100644
--- a/aconfig/codegen/cc_aconfig_library_test.go
+++ b/aconfig/codegen/cc_aconfig_library_test.go
@@ -249,6 +249,22 @@
 				aconfig_declarations: "my_aconfig_declarations",
 				mode: "force-read-only",
 			}
+
+
+			cc_library {
+    		                name: "libbase",
+    		                srcs: ["libbase.cc"],
+			}
+
+			cc_library {
+    		                name: "liblog",
+    		                srcs: ["liblog.cc"],
+			}
+
+			cc_library {
+    		                name: "libaconfig_storage_read_api_cc",
+    		                srcs: ["libaconfig_storage_read_api_cc.cc"],
+			}
 		`))
 
 	module := result.ModuleForTests("my_cc_aconfig_library", "android_arm64_armv8-a_shared").Module()
diff --git a/android/apex_contributions.go b/android/apex_contributions.go
index dd09fbf..f5c50d3 100644
--- a/android/apex_contributions.go
+++ b/android/apex_contributions.go
@@ -15,8 +15,6 @@
 package android
 
 import (
-	"strings"
-
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
@@ -115,15 +113,6 @@
 func (a *allApexContributions) SetPrebuiltSelectionInfoProvider(ctx BaseModuleContext) {
 	addContentsToProvider := func(p *PrebuiltSelectionInfoMap, m *apexContributions) {
 		for _, content := range m.Contents() {
-			// Coverage builds for TARGET_RELEASE=foo should always build from source,
-			// even if TARGET_RELEASE=foo uses prebuilt mainline modules.
-			// This is necessary because the checked-in prebuilts were generated with
-			// instrumentation turned off.
-			//
-			// Skip any prebuilt contents in coverage builds
-			if strings.HasPrefix(content, "prebuilt_") && (ctx.Config().JavaCoverageEnabled() || ctx.DeviceConfig().NativeCoverageEnabled()) {
-				continue
-			}
 			if !ctx.OtherModuleExists(content) && !ctx.Config().AllowMissingDependencies() {
 				ctx.ModuleErrorf("%s listed in apex_contributions %s does not exist\n", content, m.Name())
 			}
diff --git a/android/config.go b/android/config.go
index b60eb5c..f6711e6 100644
--- a/android/config.go
+++ b/android/config.go
@@ -818,12 +818,12 @@
 }
 
 func (c *config) IsEnvTrue(key string) bool {
-	value := c.Getenv(key)
+	value := strings.ToLower(c.Getenv(key))
 	return value == "1" || value == "y" || value == "yes" || value == "on" || value == "true"
 }
 
 func (c *config) IsEnvFalse(key string) bool {
-	value := c.Getenv(key)
+	value := strings.ToLower(c.Getenv(key))
 	return value == "0" || value == "n" || value == "no" || value == "off" || value == "false"
 }
 
@@ -2104,6 +2104,7 @@
 		"RELEASE_APEX_CONTRIBUTIONS_IPSEC",
 		"RELEASE_APEX_CONTRIBUTIONS_MEDIA",
 		"RELEASE_APEX_CONTRIBUTIONS_MEDIAPROVIDER",
+		"RELEASE_APEX_CONTRIBUTIONS_MODULE_METADATA",
 		"RELEASE_APEX_CONTRIBUTIONS_NETWORKSTACKGOOGLE",
 		"RELEASE_APEX_CONTRIBUTIONS_NEURALNETWORKS",
 		"RELEASE_APEX_CONTRIBUTIONS_ONDEVICEPERSONALIZATION",
diff --git a/android/mutator.go b/android/mutator.go
index 75ba650..9cfdb60 100644
--- a/android/mutator.go
+++ b/android/mutator.go
@@ -293,15 +293,14 @@
 	// WalkDeps, etc.
 	AddInterVariantDependency(tag blueprint.DependencyTag, from, to blueprint.Module)
 
-	// ReplaceDependencies replaces all dependencies on the identical variant of the module with the
-	// specified name with the current variant of this module.  Replacements don't take effect until
-	// after the mutator pass is finished.
+	// ReplaceDependencies finds all the variants of the module with the specified name, then
+	// replaces all dependencies onto those variants with the current variant of this module.
+	// Replacements don't take effect until after the mutator pass is finished.
 	ReplaceDependencies(string)
 
-	// ReplaceDependencies replaces all dependencies on the identical variant of the module with the
-	// specified name with the current variant of this module as long as the supplied predicate returns
-	// true.
-	//
+	// ReplaceDependenciesIf finds all the variants of the module with the specified name, then
+	// replaces all dependencies onto those variants with the current variant of this module
+	// as long as the supplied predicate returns true.
 	// Replacements don't take effect until after the mutator pass is finished.
 	ReplaceDependenciesIf(string, blueprint.ReplaceDependencyPredicate)
 
@@ -595,11 +594,16 @@
 
 func (a *androidTransitionMutator) Mutate(ctx blueprint.BottomUpMutatorContext, variation string) {
 	if am, ok := ctx.Module().(Module); ok {
+		if variation != "" {
+			// TODO: this should really be checking whether the TransitionMutator affected this module, not
+			//  the empty variant, but TransitionMutator has no concept of skipping a module.
+			base := am.base()
+			base.commonProperties.DebugMutators = append(base.commonProperties.DebugMutators, a.name)
+			base.commonProperties.DebugVariations = append(base.commonProperties.DebugVariations, variation)
+		}
+
 		mctx := bottomUpMutatorContextFactory(ctx, am, a.finalPhase)
 		defer bottomUpMutatorContextPool.Put(mctx)
-		base := am.base()
-		base.commonProperties.DebugMutators = append(base.commonProperties.DebugMutators, a.name)
-		base.commonProperties.DebugVariations = append(base.commonProperties.DebugVariations, variation)
 		a.mutator.Mutate(mctx, variation)
 	}
 }
diff --git a/android/paths.go b/android/paths.go
index 2b33f67..39b660c 100644
--- a/android/paths.go
+++ b/android/paths.go
@@ -277,6 +277,7 @@
 
 type genPathProvider interface {
 	genPathWithExt(ctx ModuleOutPathContext, subdir, ext string) ModuleGenPath
+	genPathWithExtAndTrimExt(ctx ModuleOutPathContext, subdir, ext string, trimExt string) ModuleGenPath
 }
 type objPathProvider interface {
 	objPathWithExt(ctx ModuleOutPathContext, subdir, ext string) ModuleObjPath
@@ -295,6 +296,16 @@
 	return PathForModuleGen(ctx)
 }
 
+// GenPathWithExtAndTrimExt derives a new file path in ctx's generated sources directory
+// from the current path, but with the new extension and trim the suffix.
+func GenPathWithExtAndTrimExt(ctx ModuleOutPathContext, subdir string, p Path, ext string, trimExt string) ModuleGenPath {
+	if path, ok := p.(genPathProvider); ok {
+		return path.genPathWithExtAndTrimExt(ctx, subdir, ext, trimExt)
+	}
+	ReportPathErrorf(ctx, "Tried to create generated file from unsupported path: %s(%s)", reflect.TypeOf(p).Name(), p)
+	return PathForModuleGen(ctx)
+}
+
 // ObjPathWithExt derives a new file path in ctx's object directory from the
 // current path, but with the new extension.
 func ObjPathWithExt(ctx ModuleOutPathContext, subdir string, p Path, ext string) ModuleObjPath {
@@ -1507,6 +1518,17 @@
 	return PathForModuleGen(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
 }
 
+func (p SourcePath) genPathWithExtAndTrimExt(ctx ModuleOutPathContext, subdir, ext string, trimExt string) ModuleGenPath {
+	// If Trim_extension being set, force append Output_extension without replace original extension.
+	if trimExt != "" {
+		if ext != "" {
+			return PathForModuleGen(ctx, subdir, strings.TrimSuffix(p.path, trimExt)+"."+ext)
+		}
+		return PathForModuleGen(ctx, subdir, strings.TrimSuffix(p.path, trimExt))
+	}
+	return PathForModuleGen(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
+}
+
 func (p SourcePath) objPathWithExt(ctx ModuleOutPathContext, subdir, ext string) ModuleObjPath {
 	return PathForModuleObj(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
 }
@@ -1594,6 +1616,17 @@
 	return PathForModuleGen(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
 }
 
+func (p ModuleGenPath) genPathWithExtAndTrimExt(ctx ModuleOutPathContext, subdir, ext string, trimExt string) ModuleGenPath {
+	// If Trim_extension being set, force append Output_extension without replace original extension.
+	if trimExt != "" {
+		if ext != "" {
+			return PathForModuleGen(ctx, subdir, strings.TrimSuffix(p.path, trimExt)+"."+ext)
+		}
+		return PathForModuleGen(ctx, subdir, strings.TrimSuffix(p.path, trimExt))
+	}
+	return PathForModuleGen(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
+}
+
 func (p ModuleGenPath) objPathWithExt(ctx ModuleOutPathContext, subdir, ext string) ModuleObjPath {
 	return PathForModuleObj(ctx, subdir, pathtools.ReplaceExtension(p.path, ext))
 }
diff --git a/android/prebuilt_test.go b/android/prebuilt_test.go
index 2574ed4..575b926 100644
--- a/android/prebuilt_test.go
+++ b/android/prebuilt_test.go
@@ -610,45 +610,3 @@
 		}
 		`, selectMainlineModuleContritbutions)
 }
-
-// Test that apex_contributions of prebuilt modules are ignored in coverage builds
-func TestSourceIsSelectedInCoverageBuilds(t *testing.T) {
-	prebuiltMainlineContributions := GroupFixturePreparers(
-		FixtureModifyProductVariables(func(variables FixtureProductVariables) {
-			variables.BuildFlags = map[string]string{
-				"RELEASE_APEX_CONTRIBUTIONS_ADSERVICES": "my_prebuilt_apex_contributions",
-			}
-		}),
-		FixtureMergeEnv(map[string]string{
-			"EMMA_INSTRUMENT_FRAMEWORK": "true",
-		}),
-	)
-	bp := `
-		source {
-			name: "foo",
-		}
-		prebuilt {
-			name: "foo",
-			srcs: ["prebuilt_file"],
-		}
-		apex_contributions {
-			name: "my_prebuilt_apex_contributions",
-			api_domain: "my_mainline_module",
-			contents: [
-			  "prebuilt_foo",
-			],
-		}
-		all_apex_contributions {
-			name: "all_apex_contributions",
-		}
-		`
-	ctx := GroupFixturePreparers(
-		PrepareForTestWithArchMutator,
-		PrepareForTestWithPrebuilts,
-		FixtureRegisterWithContext(registerTestPrebuiltModules),
-		prebuiltMainlineContributions).RunTestWithBp(t, bp)
-	source := ctx.ModuleForTests("foo", "android_common").Module()
-	AssertBoolEquals(t, "Source should be preferred in coverage builds", true, !source.IsHideFromMake())
-	prebuilt := ctx.ModuleForTests("prebuilt_foo", "android_common").Module()
-	AssertBoolEquals(t, "Prebuilt should not be preferred in coverage builds", false, !prebuilt.IsHideFromMake())
-}
diff --git a/android/selects_test.go b/android/selects_test.go
index 8563285..d9499a5 100644
--- a/android/selects_test.go
+++ b/android/selects_test.go
@@ -633,6 +633,61 @@
 			},
 			expectedError: "Expected all branches of a select on condition boolean_var_for_testing\\(\\) to have type bool, found string",
 		},
+		{
+			name: "Assigning select to nonconfigurable bool",
+			bp: `
+			my_module_type {
+				name: "foo",
+				my_nonconfigurable_bool: select(arch(), {
+					"x86_64": true,
+					default: false,
+				}),
+			}
+			`,
+			expectedError: `can't assign select statement to non-configurable property "my_nonconfigurable_bool"`,
+		},
+		{
+			name: "Assigning select to nonconfigurable string",
+			bp: `
+			my_module_type {
+				name: "foo",
+				my_nonconfigurable_string: select(arch(), {
+					"x86_64": "x86!",
+					default: "unknown!",
+				}),
+			}
+			`,
+			expectedError: `can't assign select statement to non-configurable property "my_nonconfigurable_string"`,
+		},
+		{
+			name: "Assigning appended selects to nonconfigurable string",
+			bp: `
+			my_module_type {
+				name: "foo",
+				my_nonconfigurable_string: select(arch(), {
+					"x86_64": "x86!",
+					default: "unknown!",
+				}) + select(os(), {
+					"darwin": "_darwin!",
+					default: "unknown!",
+				}),
+			}
+			`,
+			expectedError: `can't assign select statement to non-configurable property "my_nonconfigurable_string"`,
+		},
+		{
+			name: "Assigning select to nonconfigurable string list",
+			bp: `
+			my_module_type {
+				name: "foo",
+				my_nonconfigurable_string_list: select(arch(), {
+					"x86_64": ["foo", "bar"],
+					default: ["baz", "qux"],
+				}),
+			}
+			`,
+			expectedError: `can't assign select statement to non-configurable property "my_nonconfigurable_string_list"`,
+		},
 	}
 
 	for _, tc := range testCases {
@@ -674,11 +729,14 @@
 }
 
 type selectsTestProvider struct {
-	my_bool               *bool
-	my_string             *string
-	my_string_list        *[]string
-	my_paths              *[]string
-	replacing_string_list *[]string
+	my_bool                        *bool
+	my_string                      *string
+	my_string_list                 *[]string
+	my_paths                       *[]string
+	replacing_string_list          *[]string
+	my_nonconfigurable_bool        *bool
+	my_nonconfigurable_string      *string
+	my_nonconfigurable_string_list []string
 }
 
 func (p *selectsTestProvider) String() string {
@@ -690,23 +748,42 @@
 	if p.my_string != nil {
 		myStringStr = *p.my_string
 	}
+	myNonconfigurableStringStr := "nil"
+	if p.my_string != nil {
+		myNonconfigurableStringStr = *p.my_nonconfigurable_string
+	}
 	return fmt.Sprintf(`selectsTestProvider {
 	my_bool: %v,
 	my_string: %s,
     my_string_list: %s,
     my_paths: %s,
 	replacing_string_list %s,
-}`, myBoolStr, myStringStr, p.my_string_list, p.my_paths, p.replacing_string_list)
+	my_nonconfigurable_bool: %v,
+	my_nonconfigurable_string: %s,
+	my_nonconfigurable_string_list: %s,
+}`,
+		myBoolStr,
+		myStringStr,
+		p.my_string_list,
+		p.my_paths,
+		p.replacing_string_list,
+		p.my_nonconfigurable_bool,
+		myNonconfigurableStringStr,
+		p.my_nonconfigurable_string_list,
+	)
 }
 
 var selectsTestProviderKey = blueprint.NewProvider[selectsTestProvider]()
 
 type selectsMockModuleProperties struct {
-	My_bool               proptools.Configurable[bool]
-	My_string             proptools.Configurable[string]
-	My_string_list        proptools.Configurable[[]string]
-	My_paths              proptools.Configurable[[]string] `android:"path"`
-	Replacing_string_list proptools.Configurable[[]string] `android:"replace_instead_of_append,arch_variant"`
+	My_bool                        proptools.Configurable[bool]
+	My_string                      proptools.Configurable[string]
+	My_string_list                 proptools.Configurable[[]string]
+	My_paths                       proptools.Configurable[[]string] `android:"path"`
+	Replacing_string_list          proptools.Configurable[[]string] `android:"replace_instead_of_append,arch_variant"`
+	My_nonconfigurable_bool        *bool
+	My_nonconfigurable_string      *string
+	My_nonconfigurable_string_list []string
 }
 
 type selectsMockModule struct {
@@ -717,11 +794,14 @@
 
 func (p *selectsMockModule) GenerateAndroidBuildActions(ctx ModuleContext) {
 	SetProvider(ctx, selectsTestProviderKey, selectsTestProvider{
-		my_bool:               p.properties.My_bool.Get(ctx),
-		my_string:             p.properties.My_string.Get(ctx),
-		my_string_list:        p.properties.My_string_list.Get(ctx),
-		my_paths:              p.properties.My_paths.Get(ctx),
-		replacing_string_list: p.properties.Replacing_string_list.Get(ctx),
+		my_bool:                        p.properties.My_bool.Get(ctx),
+		my_string:                      p.properties.My_string.Get(ctx),
+		my_string_list:                 p.properties.My_string_list.Get(ctx),
+		my_paths:                       p.properties.My_paths.Get(ctx),
+		replacing_string_list:          p.properties.Replacing_string_list.Get(ctx),
+		my_nonconfigurable_bool:        p.properties.My_nonconfigurable_bool,
+		my_nonconfigurable_string:      p.properties.My_nonconfigurable_string,
+		my_nonconfigurable_string_list: p.properties.My_nonconfigurable_string_list,
 	})
 }
 
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 3e284b1..1be1048 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3671,34 +3671,13 @@
 
 func vndkLibrariesTxtFiles(vers ...string) (result string) {
 	for _, v := range vers {
-		if v == "current" {
-			for _, txt := range []string{"vndkcore", "vndksp", "vndkprivate", "vndkproduct"} {
-				result += `
-					` + txt + `_libraries_txt {
-						name: "` + txt + `.libraries.txt",
-						insert_vndk_version: true,
-					}
-				`
-			}
+		for _, txt := range []string{"llndk", "vndkcore", "vndksp", "vndkprivate", "vndkproduct"} {
 			result += `
-				llndk_libraries_txt {
-					name: "llndk.libraries.txt",
-				}
-				llndk_libraries_txt_for_apex {
-					name: "llndk.libraries.txt.apex",
-					stem: "llndk.libraries.txt",
-					insert_vndk_version: true,
-				}
-			`
-		} else {
-			for _, txt := range []string{"llndk", "vndkcore", "vndksp", "vndkprivate", "vndkproduct"} {
-				result += `
 					prebuilt_etc {
 						name: "` + txt + `.libraries.` + v + `.txt",
 						src: "dummy.txt",
 					}
 				`
-			}
 		}
 	}
 	return
diff --git a/bin/build-flag b/bin/build-flag
new file mode 100755
index 0000000..dc404bc
--- /dev/null
+++ b/bin/build-flag
@@ -0,0 +1,28 @@
+#!/bin/bash -eu
+#
+# Copyright 2017 Google Inc. All rights reserved.
+#
+# 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.
+
+source $(cd $(dirname $BASH_SOURCE) &> /dev/null && pwd)/../../make/shell_utils.sh
+require_top
+
+# Save the current PWD for use in soong_ui
+export ORIGINAL_PWD=${PWD}
+export TOP=$(gettop)
+source ${TOP}/build/soong/scripts/microfactory.bash
+
+soong_build_go build-flag android/soong/cmd/release_config/build_flag
+
+cd ${TOP}
+exec "$(getoutdir)/build-flag" "$@"
diff --git a/cc/cc.go b/cc/cc.go
index e3954d7..e9cdc34 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -50,6 +50,7 @@
 	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
 		ctx.BottomUp("sdk", sdkMutator).Parallel()
 		ctx.BottomUp("vndk", VndkMutator).Parallel()
+		ctx.BottomUp("llndk", llndkMutator).Parallel()
 		ctx.BottomUp("link", LinkageMutator).Parallel()
 		ctx.BottomUp("test_per_src", TestPerSrcMutator).Parallel()
 		ctx.BottomUp("version", versionMutator).Parallel()
diff --git a/cc/linker.go b/cc/linker.go
index 9686697..56a68b2 100644
--- a/cc/linker.go
+++ b/cc/linker.go
@@ -330,6 +330,7 @@
 		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Vendor.Exclude_static_libs)
 		deps.HeaderLibs = append(deps.HeaderLibs, linker.Properties.Target.Vendor.Header_libs...)
 		deps.HeaderLibs = removeListFromList(deps.HeaderLibs, linker.Properties.Target.Vendor.Exclude_header_libs)
+		deps.ReexportHeaderLibHeaders = removeListFromList(deps.ReexportHeaderLibHeaders, linker.Properties.Target.Vendor.Exclude_header_libs)
 		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Vendor.Exclude_static_libs)
 		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Vendor.Exclude_static_libs)
 		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Vendor.Exclude_runtime_libs)
@@ -342,6 +343,7 @@
 		deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Target.Product.Static_libs...)
 		deps.StaticLibs = removeListFromList(deps.StaticLibs, linker.Properties.Target.Product.Exclude_static_libs)
 		deps.HeaderLibs = removeListFromList(deps.HeaderLibs, linker.Properties.Target.Product.Exclude_header_libs)
+		deps.ReexportHeaderLibHeaders = removeListFromList(deps.ReexportHeaderLibHeaders, linker.Properties.Target.Product.Exclude_header_libs)
 		deps.ReexportStaticLibHeaders = removeListFromList(deps.ReexportStaticLibHeaders, linker.Properties.Target.Product.Exclude_static_libs)
 		deps.WholeStaticLibs = removeListFromList(deps.WholeStaticLibs, linker.Properties.Target.Product.Exclude_static_libs)
 		deps.RuntimeLibs = removeListFromList(deps.RuntimeLibs, linker.Properties.Target.Product.Exclude_runtime_libs)
diff --git a/cc/llndk_library.go b/cc/llndk_library.go
index 9e727a1..ae9da98 100644
--- a/cc/llndk_library.go
+++ b/cc/llndk_library.go
@@ -16,12 +16,12 @@
 
 import (
 	"android/soong/android"
+	"android/soong/etc"
 	"strings"
 )
 
 var (
 	llndkLibrarySuffix = ".llndk"
-	llndkHeadersSuffix = ".llndk"
 )
 
 // Holds properties to describe a stub shared library based on the provided version file.
@@ -78,3 +78,138 @@
 	ctx.Strict("LLNDK_MOVED_TO_APEX_LIBRARIES",
 		strings.Join(android.SortedKeys(movedToApexLlndkLibraries), " "))
 }
+
+func init() {
+	RegisterLlndkLibraryTxtType(android.InitRegistrationContext)
+}
+
+func RegisterLlndkLibraryTxtType(ctx android.RegistrationContext) {
+	ctx.RegisterParallelSingletonModuleType("llndk_libraries_txt", llndkLibrariesTxtFactory)
+}
+
+type llndkLibrariesTxtModule struct {
+	android.SingletonModuleBase
+
+	outputFile  android.OutputPath
+	moduleNames []string
+	fileNames   []string
+}
+
+var _ etc.PrebuiltEtcModule = &llndkLibrariesTxtModule{}
+var _ android.OutputFileProducer = &llndkLibrariesTxtModule{}
+
+// llndk_libraries_txt is a singleton module whose content is a list of LLNDK libraries
+// generated by Soong but can be referenced by other modules.
+// For example, apex_vndk can depend on these files as prebuilt.
+// Make uses LLNDK_LIBRARIES to determine which libraries to install.
+// HWASAN is only part of the LL-NDK in builds in which libc depends on HWASAN.
+// Therefore, by removing the library here, we cause it to only be installed if libc
+// depends on it.
+func llndkLibrariesTxtFactory() android.SingletonModule {
+	m := &llndkLibrariesTxtModule{}
+	android.InitAndroidArchModule(m, android.DeviceSupported, android.MultilibCommon)
+	return m
+}
+
+func (txt *llndkLibrariesTxtModule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	filename := txt.Name()
+
+	txt.outputFile = android.PathForModuleOut(ctx, filename).OutputPath
+
+	installPath := android.PathForModuleInstall(ctx, "etc")
+	ctx.InstallFile(installPath, filename, txt.outputFile)
+}
+
+func (txt *llndkLibrariesTxtModule) GenerateSingletonBuildActions(ctx android.SingletonContext) {
+	ctx.VisitAllModules(func(m android.Module) {
+		if c, ok := m.(*Module); ok && c.VendorProperties.IsLLNDK && !c.Header() && !c.IsVndkPrebuiltLibrary() {
+			filename, err := getVndkFileName(c)
+			if err != nil {
+				ctx.ModuleErrorf(m, "%s", err)
+			}
+
+			if !strings.HasPrefix(ctx.ModuleName(m), "libclang_rt.hwasan") {
+				txt.moduleNames = append(txt.moduleNames, ctx.ModuleName(m))
+			}
+			txt.fileNames = append(txt.fileNames, filename)
+		}
+	})
+	txt.moduleNames = android.SortedUniqueStrings(txt.moduleNames)
+	txt.fileNames = android.SortedUniqueStrings(txt.fileNames)
+
+	android.WriteFileRule(ctx, txt.outputFile, strings.Join(txt.fileNames, "\n"))
+}
+
+func (txt *llndkLibrariesTxtModule) AndroidMkEntries() []android.AndroidMkEntries {
+	return []android.AndroidMkEntries{{
+		Class:      "ETC",
+		OutputFile: android.OptionalPathForPath(txt.outputFile),
+		ExtraEntries: []android.AndroidMkExtraEntriesFunc{
+			func(ctx android.AndroidMkExtraEntriesContext, entries *android.AndroidMkEntries) {
+				entries.SetString("LOCAL_MODULE_STEM", txt.outputFile.Base())
+			},
+		},
+	}}
+}
+
+func (txt *llndkLibrariesTxtModule) MakeVars(ctx android.MakeVarsContext) {
+	ctx.Strict("LLNDK_LIBRARIES", strings.Join(txt.moduleNames, " "))
+}
+
+// PrebuiltEtcModule interface
+func (txt *llndkLibrariesTxtModule) OutputFile() android.OutputPath {
+	return txt.outputFile
+}
+
+// PrebuiltEtcModule interface
+func (txt *llndkLibrariesTxtModule) BaseDir() string {
+	return "etc"
+}
+
+// PrebuiltEtcModule interface
+func (txt *llndkLibrariesTxtModule) SubDir() string {
+	return ""
+}
+
+func (txt *llndkLibrariesTxtModule) OutputFiles(tag string) (android.Paths, error) {
+	return android.Paths{txt.outputFile}, nil
+}
+
+func llndkMutator(mctx android.BottomUpMutatorContext) {
+	m, ok := mctx.Module().(*Module)
+	if !ok {
+		return
+	}
+
+	if shouldSkipLlndkMutator(m) {
+		return
+	}
+
+	lib, isLib := m.linker.(*libraryDecorator)
+	prebuiltLib, isPrebuiltLib := m.linker.(*prebuiltLibraryLinker)
+
+	if m.InVendorOrProduct() && isLib && lib.hasLLNDKStubs() {
+		m.VendorProperties.IsLLNDK = true
+	}
+	if m.InVendorOrProduct() && isPrebuiltLib && prebuiltLib.hasLLNDKStubs() {
+		m.VendorProperties.IsLLNDK = true
+	}
+
+	if m.IsVndkPrebuiltLibrary() && !m.IsVndk() {
+		m.VendorProperties.IsLLNDK = true
+	}
+}
+
+// Check for modules that mustn't be LLNDK
+func shouldSkipLlndkMutator(m *Module) bool {
+	if !m.Enabled() {
+		return true
+	}
+	if !m.Device() {
+		return true
+	}
+	if m.Target().NativeBridge == android.NativeBridgeEnabled {
+		return true
+	}
+	return false
+}
diff --git a/cc/prebuilt.go b/cc/prebuilt.go
index cbb5d58..e9f790f 100644
--- a/cc/prebuilt.go
+++ b/cc/prebuilt.go
@@ -177,7 +177,7 @@
 				implicits = append(implicits, importLibOutputFile)
 
 				ctx.Build(pctx, android.BuildParams{
-					Rule:        android.Cp,
+					Rule:        android.CpExecutable,
 					Description: "prebuilt import library",
 					Input:       importLibSrc,
 					Output:      importLibOutputFile,
@@ -188,7 +188,7 @@
 			}
 
 			ctx.Build(pctx, android.BuildParams{
-				Rule:        android.Cp,
+				Rule:        android.CpExecutable,
 				Description: "prebuilt shared library",
 				Implicits:   implicits,
 				Input:       in,
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 188b793..a0cbb51 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -55,7 +55,6 @@
 		// higher number of "optimized out" stack variables.
 		// b/112437883.
 		"-instcombine-lower-dbg-declare=0",
-		"-hwasan-use-after-scope=1",
 		"-dom-tree-reachability-max-bbs-to-explore=128",
 	}
 
@@ -82,7 +81,8 @@
 		"-fno-sanitize-recover=integer,undefined"}
 	hwasanGlobalOptions = []string{"heap_history_size=1023", "stack_history_size=512",
 		"export_memory_stats=0", "max_malloc_fill_size=131072", "malloc_fill_byte=0"}
-	memtagStackCommonFlags = []string{"-march=armv8-a+memtag", "-mllvm", "-dom-tree-reachability-max-bbs-to-explore=128"}
+	memtagStackCommonFlags = []string{"-march=armv8-a+memtag"}
+	memtagStackLlvmFlags = []string{"-dom-tree-reachability-max-bbs-to-explore=128"}
 
 	hostOnlySanitizeFlags   = []string{"-fno-sanitize-recover=all"}
 	deviceOnlySanitizeFlags = []string{"-fsanitize-trap=all"}
@@ -884,6 +884,13 @@
 		flags.Local.CFlags = append(flags.Local.CFlags, memtagStackCommonFlags...)
 		flags.Local.AsFlags = append(flags.Local.AsFlags, memtagStackCommonFlags...)
 		flags.Local.LdFlags = append(flags.Local.LdFlags, memtagStackCommonFlags...)
+
+		for _, flag := range memtagStackLlvmFlags {
+			flags.Local.CFlags = append(flags.Local.CFlags, "-mllvm", flag)
+		}
+		for _, flag := range memtagStackLlvmFlags {
+			flags.Local.LdFlags = append(flags.Local.LdFlags, "-Wl,-mllvm,"+flag)
+		}
 	}
 
 	if (Bool(sanProps.Memtag_heap) || Bool(sanProps.Memtag_stack) || Bool(sanProps.Memtag_globals)) && ctx.binary() {
diff --git a/cc/testing.go b/cc/testing.go
index 20c435a..4b4e866 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -554,6 +554,7 @@
 		ctx.RegisterModuleType("vndk_prebuilt_shared", VndkPrebuiltSharedFactory)
 
 		RegisterVndkLibraryTxtTypes(ctx)
+		RegisterLlndkLibraryTxtType(ctx)
 	}),
 
 	// Additional files needed in tests that disallow non-existent source files.
@@ -570,17 +571,17 @@
 
 	// Additional files needed in tests that disallow non-existent source.
 	android.MockFS{
-		"defaults/cc/common/libc.map.txt":      nil,
-		"defaults/cc/common/libdl.map.txt":     nil,
-		"defaults/cc/common/libft2.map.txt":    nil,
-		"defaults/cc/common/libm.map.txt":      nil,
-		"defaults/cc/common/ndk_libc++_shared": nil,
-		"defaults/cc/common/crtbegin_so.c":     nil,
-		"defaults/cc/common/crtbegin.c":        nil,
-		"defaults/cc/common/crtend_so.c":       nil,
-		"defaults/cc/common/crtend.c":          nil,
-		"defaults/cc/common/crtbrand.c":        nil,
-		"external/compiler-rt/lib/cfi/cfi_blocklist.txt":   nil,
+		"defaults/cc/common/libc.map.txt":                nil,
+		"defaults/cc/common/libdl.map.txt":               nil,
+		"defaults/cc/common/libft2.map.txt":              nil,
+		"defaults/cc/common/libm.map.txt":                nil,
+		"defaults/cc/common/ndk_libc++_shared":           nil,
+		"defaults/cc/common/crtbegin_so.c":               nil,
+		"defaults/cc/common/crtbegin.c":                  nil,
+		"defaults/cc/common/crtend_so.c":                 nil,
+		"defaults/cc/common/crtend.c":                    nil,
+		"defaults/cc/common/crtbrand.c":                  nil,
+		"external/compiler-rt/lib/cfi/cfi_blocklist.txt": nil,
 
 		"defaults/cc/common/libclang_rt.ubsan_minimal.android_arm64.a": nil,
 		"defaults/cc/common/libclang_rt.ubsan_minimal.android_arm.a":   nil,
@@ -702,6 +703,7 @@
 	ctx.RegisterModuleType("vndk_prebuilt_shared", VndkPrebuiltSharedFactory)
 
 	RegisterVndkLibraryTxtTypes(ctx)
+	RegisterLlndkLibraryTxtType(ctx)
 
 	ctx.PreArchMutators(android.RegisterDefaultsPreArchMutators)
 	android.RegisterPrebuiltMutators(ctx)
diff --git a/cc/vndk.go b/cc/vndk.go
index 14b44b6..50e6d4b 100644
--- a/cc/vndk.go
+++ b/cc/vndk.go
@@ -219,7 +219,6 @@
 type moduleListerFunc func(ctx android.SingletonContext) (moduleNames, fileNames []string)
 
 var (
-	llndkLibraries                = vndkModuleLister(func(m *Module) bool { return m.VendorProperties.IsLLNDK && !m.Header() })
 	vndkSPLibraries               = vndkModuleLister(func(m *Module) bool { return m.VendorProperties.IsVNDKSP })
 	vndkCoreLibraries             = vndkModuleLister(func(m *Module) bool { return m.VendorProperties.IsVNDKCore })
 	vndkPrivateLibraries          = vndkModuleLister(func(m *Module) bool { return m.VendorProperties.IsVNDKPrivate })
@@ -378,19 +377,12 @@
 	prebuiltLib, isPrebuiltLib := m.linker.(*prebuiltLibraryLinker)
 
 	if m.InVendorOrProduct() && isLib && lib.hasLLNDKStubs() {
-		m.VendorProperties.IsLLNDK = true
 		m.VendorProperties.IsVNDKPrivate = Bool(lib.Properties.Llndk.Private)
 	}
 	if m.InVendorOrProduct() && isPrebuiltLib && prebuiltLib.hasLLNDKStubs() {
-		m.VendorProperties.IsLLNDK = true
 		m.VendorProperties.IsVNDKPrivate = Bool(prebuiltLib.Properties.Llndk.Private)
 	}
 
-	if m.IsVndkPrebuiltLibrary() && !m.IsVndk() {
-		m.VendorProperties.IsLLNDK = true
-		// TODO(b/280697209): copy "llndk.private" flag to vndk_prebuilt_shared
-	}
-
 	if (isLib && lib.buildShared()) || (isPrebuiltLib && prebuiltLib.buildShared()) {
 		if m.vndkdep != nil && m.vndkdep.isVndk() && !m.vndkdep.isVndkExt() {
 			processVndkLibrary(mctx, m)
@@ -404,8 +396,6 @@
 }
 
 func RegisterVndkLibraryTxtTypes(ctx android.RegistrationContext) {
-	ctx.RegisterParallelSingletonModuleType("llndk_libraries_txt", llndkLibrariesTxtFactory)
-	ctx.RegisterParallelSingletonModuleType("llndk_libraries_txt_for_apex", llndkLibrariesTxtApexOnlyFactory)
 	ctx.RegisterParallelSingletonModuleType("vndksp_libraries_txt", vndkSPLibrariesTxtFactory)
 	ctx.RegisterParallelSingletonModuleType("vndkcore_libraries_txt", vndkCoreLibrariesTxtFactory)
 	ctx.RegisterParallelSingletonModuleType("vndkprivate_libraries_txt", vndkPrivateLibrariesTxtFactory)
@@ -435,25 +425,6 @@
 var _ etc.PrebuiltEtcModule = &vndkLibrariesTxt{}
 var _ android.OutputFileProducer = &vndkLibrariesTxt{}
 
-// llndk_libraries_txt is a singleton module whose content is a list of LLNDK libraries
-// generated by Soong.
-// Make uses LLNDK_LIBRARIES to determine which libraries to install.
-// HWASAN is only part of the LLNDK in builds in which libc depends on HWASAN.
-// Therefore, by removing the library here, we cause it to only be installed if libc
-// depends on it.
-func llndkLibrariesTxtFactory() android.SingletonModule {
-	return newVndkLibrariesWithMakeVarFilter(llndkLibraries, "LLNDK_LIBRARIES", "libclang_rt.hwasan")
-}
-
-// llndk_libraries_txt_for_apex is a singleton module that provide the same LLNDK libraries list
-// with the llndk_libraries_txt, but skips setting make variable LLNDK_LIBRARIES. So, it must not
-// be used without installing llndk_libraries_txt singleton.
-// We include llndk_libraries_txt by default to install the llndk.libraries.txt file to system/etc.
-// This singleton module is to install the llndk.libraries.<ver>.txt file to vndk apex.
-func llndkLibrariesTxtApexOnlyFactory() android.SingletonModule {
-	return newVndkLibrariesWithMakeVarFilter(llndkLibraries, "", "libclang_rt.hwasan")
-}
-
 // vndksp_libraries_txt is a singleton module whose content is a list of VNDKSP libraries
 // generated by Soong but can be referenced by other modules.
 // For example, apex_vndk can depend on these files as prebuilt.
diff --git a/cmd/release_config/build_flag/main.go b/cmd/release_config/build_flag/main.go
index a8e6326..56c49d8 100644
--- a/cmd/release_config/build_flag/main.go
+++ b/cmd/release_config/build_flag/main.go
@@ -1,10 +1,12 @@
 package main
 
 import (
+	"cmp"
 	"flag"
 	"fmt"
 	"os"
 	"path/filepath"
+	"slices"
 	"strings"
 
 	rc_lib "android/soong/cmd/release_config/release_config_lib"
@@ -36,6 +38,16 @@
 
 	// Disable warning messages
 	quiet bool
+
+	// Show all release configs
+	allReleases bool
+
+	// Call get_build_var PRODUCT_RELEASE_CONFIG_MAPS to get the
+	// product-specific map directories.
+	useGetBuildVar bool
+
+	// Panic on errors.
+	debug bool
 }
 
 type CommandFunc func(*rc_lib.ReleaseConfigs, Flags, string, []string) error
@@ -60,6 +72,14 @@
 	return "", fmt.Errorf("Could not determine directory from %s", path)
 }
 
+func MarshalFlagDefaultValue(config *rc_lib.ReleaseConfig, name string) (ret string, err error) {
+	fa, ok := config.FlagArtifacts[name]
+	if !ok {
+		return "", fmt.Errorf("%s not found in %s", name, config.Name)
+	}
+	return rc_lib.MarshalValue(fa.Traces[0].Value), nil
+}
+
 func MarshalFlagValue(config *rc_lib.ReleaseConfig, name string) (ret string, err error) {
 	fa, ok := config.FlagArtifacts[name]
 	if !ok {
@@ -68,19 +88,41 @@
 	return rc_lib.MarshalValue(fa.Value), nil
 }
 
+// Returns a list of ReleaseConfig objects for which to process flags.
 func GetReleaseArgs(configs *rc_lib.ReleaseConfigs, commonFlags Flags) ([]*rc_lib.ReleaseConfig, error) {
 	var all bool
-	relFlags := flag.NewFlagSet("set", flag.ExitOnError)
-	relFlags.BoolVar(&all, "all", false, "Display all flags")
+	relFlags := flag.NewFlagSet("releaseFlags", flag.ExitOnError)
+	relFlags.BoolVar(&all, "all", false, "Display all releases")
 	relFlags.Parse(commonFlags.targetReleases)
 	var ret []*rc_lib.ReleaseConfig
-	if all {
+	if all || commonFlags.allReleases {
+		sortMap := map[string]int{
+			"trunk_staging": 0,
+			"trunk_food":    10,
+			"trunk":         20,
+			// Anything not listed above, uses this for key 1 in the sort.
+			"-default": 100,
+		}
+
 		for _, config := range configs.ReleaseConfigs {
 			ret = append(ret, config)
 		}
+		slices.SortFunc(ret, func(a, b *rc_lib.ReleaseConfig) int {
+			mapValue := func(v *rc_lib.ReleaseConfig) int {
+				if v, ok := sortMap[v.Name]; ok {
+					return v
+				}
+				return sortMap["-default"]
+			}
+			if n := cmp.Compare(mapValue(a), mapValue(b)); n != 0 {
+				return n
+			}
+			return cmp.Compare(a.Name, b.Name)
+		})
 		return ret, nil
 	}
 	for _, arg := range relFlags.Args() {
+		// Return releases in the order that they were given.
 		config, err := configs.GetReleaseConfig(arg)
 		if err != nil {
 			return nil, err
@@ -92,12 +134,17 @@
 
 func GetCommand(configs *rc_lib.ReleaseConfigs, commonFlags Flags, cmd string, args []string) error {
 	isTrace := cmd == "trace"
+	isSet := cmd == "set"
+
 	var all bool
-	getFlags := flag.NewFlagSet("set", flag.ExitOnError)
+	getFlags := flag.NewFlagSet("get", flag.ExitOnError)
 	getFlags.BoolVar(&all, "all", false, "Display all flags")
 	getFlags.Parse(args)
 	args = getFlags.Args()
 
+	if isSet {
+		commonFlags.allReleases = true
+	}
 	releaseConfigList, err := GetReleaseArgs(configs, commonFlags)
 	if err != nil {
 		return err
@@ -113,21 +160,72 @@
 		}
 	}
 
-	showName := len(releaseConfigList) > 1 || len(args) > 1
-	for _, config := range releaseConfigList {
-		var configName string
-		if len(releaseConfigList) > 1 {
-			configName = fmt.Sprintf("%s.", config.Name)
-		}
+	var maxVariableNameLen, maxReleaseNameLen int
+	var releaseNameFormat, variableNameFormat string
+	valueFormat := "%s"
+	showReleaseName := len(releaseConfigList) > 1
+	showVariableName := len(args) > 1
+	if showVariableName {
 		for _, arg := range args {
-			val, err := MarshalFlagValue(config, arg)
-			if err != nil {
-				return err
+			maxVariableNameLen = max(len(arg), maxVariableNameLen)
+		}
+		variableNameFormat = fmt.Sprintf("%%-%ds ", maxVariableNameLen)
+		valueFormat = "'%s'"
+	}
+	if showReleaseName {
+		for _, config := range releaseConfigList {
+			maxReleaseNameLen = max(len(config.Name), maxReleaseNameLen)
+		}
+		releaseNameFormat = fmt.Sprintf("%%-%ds ", maxReleaseNameLen)
+		valueFormat = "'%s'"
+	}
+
+	outputOneLine := func(variable, release, value, valueFormat string) {
+		var outStr string
+		if showVariableName {
+			outStr += fmt.Sprintf(variableNameFormat, variable)
+		}
+		if showReleaseName {
+			outStr += fmt.Sprintf(releaseNameFormat, release)
+		}
+		outStr += fmt.Sprintf(valueFormat, value)
+		fmt.Println(outStr)
+	}
+
+	for _, arg := range args {
+		if _, ok := configs.FlagArtifacts[arg]; !ok {
+			return fmt.Errorf("%s is not a defined build flag", arg)
+		}
+	}
+
+	for _, arg := range args {
+		for _, config := range releaseConfigList {
+			if isSet {
+				// If this is from the set command, format the output as:
+				// <default>           ""
+				// trunk_staging       ""
+				// trunk               ""
+				//
+				// ap1a                ""
+				// ...
+				switch {
+				case config.Name == "trunk_staging":
+					defaultValue, err := MarshalFlagDefaultValue(config, arg)
+					if err != nil {
+						return err
+					}
+					outputOneLine(arg, "<default>", defaultValue, valueFormat)
+				case config.AconfigFlagsOnly:
+					continue
+				case config.Name == "trunk":
+					fmt.Println()
+				}
 			}
-			if showName {
-				fmt.Printf("%s%s=%s\n", configName, arg, val)
+			val, err := MarshalFlagValue(config, arg)
+			if err == nil {
+				outputOneLine(arg, config.Name, val, valueFormat)
 			} else {
-				fmt.Printf("%s\n", val)
+				outputOneLine(arg, config.Name, "REDACTED", "%s")
 			}
 			if isTrace {
 				for _, trace := range config.FlagArtifacts[arg].Traces {
@@ -160,6 +258,9 @@
 	if err != nil {
 		return err
 	}
+	if release.AconfigFlagsOnly {
+		return fmt.Errorf("%s does not allow build flag overrides", targetRelease)
+	}
 	flagArtifact, ok := release.FlagArtifacts[name]
 	if !ok {
 		return fmt.Errorf("Unknown build flag %s", name)
@@ -177,55 +278,79 @@
 		Value: rc_lib.UnmarshalValue(value),
 	}
 	flagPath := filepath.Join(valueDir, "flag_values", targetRelease, fmt.Sprintf("%s.textproto", name))
-	return rc_lib.WriteMessage(flagPath, flagValue)
+	err = rc_lib.WriteMessage(flagPath, flagValue)
+	if err != nil {
+		return err
+	}
+
+	// Reload the release configs.
+	configs, err = rc_lib.ReadReleaseConfigMaps(commonFlags.maps, commonFlags.targetReleases[0], commonFlags.useGetBuildVar)
+	if err != nil {
+		return err
+	}
+	err = GetCommand(configs, commonFlags, cmd, args[0:1])
+	if err != nil {
+		return err
+	}
+	fmt.Printf("Updated: %s\n", flagPath)
+	return nil
 }
 
 func main() {
-	var err error
 	var commonFlags Flags
 	var configs *rc_lib.ReleaseConfigs
-	var useBuildVar bool
+	topDir, err := rc_lib.GetTopDir()
 
-	outEnv := os.Getenv("OUT_DIR")
-	if outEnv == "" {
-		outEnv = "out"
-	}
 	// Handle the common arguments
-	flag.StringVar(&commonFlags.top, "top", ".", "path to top of workspace")
+	flag.StringVar(&commonFlags.top, "top", topDir, "path to top of workspace")
 	flag.BoolVar(&commonFlags.quiet, "quiet", false, "disable warning messages")
 	flag.Var(&commonFlags.maps, "map", "path to a release_config_map.textproto. may be repeated")
-	flag.StringVar(&commonFlags.outDir, "out_dir", rc_lib.GetDefaultOutDir(), "basepath for the output. Multiple formats are created")
+	flag.StringVar(&commonFlags.outDir, "out-dir", rc_lib.GetDefaultOutDir(), "basepath for the output. Multiple formats are created")
 	flag.Var(&commonFlags.targetReleases, "release", "TARGET_RELEASE for this build")
-	flag.BoolVar(&useBuildVar, "use_get_build_var", true, "use get_build_var PRODUCT_RELEASE_CONFIG_MAPS")
+	flag.BoolVar(&commonFlags.allReleases, "all-releases", false, "operate on all releases. (Ignored for set command)")
+	flag.BoolVar(&commonFlags.useGetBuildVar, "use-get-build-var", true, "use get_build_var PRODUCT_RELEASE_CONFIG_MAPS to get needed maps")
+	flag.BoolVar(&commonFlags.debug, "debug", false, "turn on debugging output for errors")
 	flag.Parse()
 
+	errorExit := func(err error) {
+		if commonFlags.debug {
+			panic(err)
+		}
+		fmt.Fprintf(os.Stderr, "%s\n", err)
+		os.Exit(1)
+	}
+
 	if commonFlags.quiet {
 		rc_lib.DisableWarnings()
 	}
 
 	if len(commonFlags.targetReleases) == 0 {
-		commonFlags.targetReleases = rc_lib.StringList{"trunk_staging"}
+		release, ok := os.LookupEnv("TARGET_RELEASE")
+		if ok {
+			commonFlags.targetReleases = rc_lib.StringList{release}
+		} else {
+			commonFlags.targetReleases = rc_lib.StringList{"trunk_staging"}
+		}
 	}
 
 	if err = os.Chdir(commonFlags.top); err != nil {
-		panic(err)
+		errorExit(err)
 	}
 
 	// Get the current state of flagging.
 	relName := commonFlags.targetReleases[0]
 	if relName == "--all" || relName == "-all" {
-		// If the users said `--release --all`, grab trunk staging for simplicity.
-		relName = "trunk_staging"
+		commonFlags.allReleases = true
 	}
-	configs, err = rc_lib.ReadReleaseConfigMaps(commonFlags.maps, relName, true)
+	configs, err = rc_lib.ReadReleaseConfigMaps(commonFlags.maps, relName, commonFlags.useGetBuildVar)
 	if err != nil {
-		panic(err)
+		errorExit(err)
 	}
 
 	if cmd, ok := commandMap[flag.Arg(0)]; ok {
 		args := flag.Args()
 		if err = cmd(configs, commonFlags, args[0], args[1:]); err != nil {
-			panic(err)
+			errorExit(err)
 		}
 	}
 }
diff --git a/cmd/release_config/crunch_flags/main.go b/cmd/release_config/crunch_flags/main.go
index b67374a..4d763c8 100644
--- a/cmd/release_config/crunch_flags/main.go
+++ b/cmd/release_config/crunch_flags/main.go
@@ -15,18 +15,30 @@
 	"google.golang.org/protobuf/proto"
 )
 
-// When a flag declaration has an initial value that is a string, the default workflow is PREBUILT.
-// If the flag name starts with any of prefixes in manualFlagNamePrefixes, it is MANUAL.
-var manualFlagNamePrefixes []string = []string{
-	"RELEASE_ACONFIG_",
-	"RELEASE_PLATFORM_",
-}
+var (
+	// When a flag declaration has an initial value that is a string, the default workflow is PREBUILT.
+	// If the flag name starts with any of prefixes in manualFlagNamePrefixes, it is MANUAL.
+	manualFlagNamePrefixes []string = []string{
+		"RELEASE_ACONFIG_",
+		"RELEASE_PLATFORM_",
+		"RELEASE_BUILD_FLAGS_",
+	}
 
-var defaultFlagNamespace string = "android_UNKNOWN"
+	// Set `aconfig_flags_only: true` in these release configs.
+	aconfigFlagsOnlyConfigs map[string]bool = map[string]bool{
+		"trunk_food": true,
+	}
+
+	// Default namespace value.  This is intentionally invalid.
+	defaultFlagNamespace string = "android_UNKNOWN"
+
+	// What is the current name for "next".
+	nextName string = "ap3a"
+)
 
 func RenameNext(name string) string {
 	if name == "next" {
-		return "ap3a"
+		return nextName
 	}
 	return name
 }
@@ -205,6 +217,9 @@
 				fmt.Printf("%s: Unexpected value %s=%s\n", path, valName, valValue)
 			}
 			if flagValue != nil {
+				if releaseProto.GetAconfigFlagsOnly() {
+					return fmt.Errorf("%s does not allow build flag overrides", RenameNext(name))
+				}
 				valPath := filepath.Join(dir, "flag_values", RenameNext(name), fmt.Sprintf("%s.textproto", valName))
 				err := WriteFile(valPath, flagValue)
 				if err != nil {
@@ -285,6 +300,9 @@
 		releaseConfig := &rc_proto.ReleaseConfig{
 			Name: proto.String(RenameNext(name)),
 		}
+		if aconfigFlagsOnlyConfigs[name] {
+			releaseConfig.AconfigFlagsOnly = proto.Bool(true)
+		}
 		configFiles := config[configRegexp.SubexpIndex("files")]
 		files := strings.Split(strings.ReplaceAll(configFiles, "$(local_dir)", dir+"/"), " ")
 		configInherits := config[configRegexp.SubexpIndex("inherits")]
@@ -311,16 +329,26 @@
 	var dirs rc_lib.StringList
 	var namespacesFile string
 	var descriptionsFile string
+	var debug bool
 	defaultTopDir, err := rc_lib.GetTopDir()
 
 	flag.StringVar(&top, "top", defaultTopDir, "path to top of workspace")
 	flag.Var(&dirs, "dir", "directory to process, relative to the top of the workspace")
 	flag.StringVar(&namespacesFile, "namespaces", "", "location of file with 'flag_name namespace' information")
 	flag.StringVar(&descriptionsFile, "descriptions", "", "location of file with 'directory description' information")
+	flag.BoolVar(&debug, "debug", false, "turn on debugging output for errors")
 	flag.Parse()
 
+	errorExit := func(err error) {
+		if debug {
+			panic(err)
+		}
+		fmt.Fprintf(os.Stderr, "%s\n", err)
+		os.Exit(1)
+	}
+
 	if err = os.Chdir(top); err != nil {
-		panic(err)
+		errorExit(err)
 	}
 	if len(dirs) == 0 {
 		dirs = rc_lib.StringList{"build/release", "vendor/google_shared/build/release", "vendor/google/release"}
@@ -330,12 +358,12 @@
 	if namespacesFile != "" {
 		data, err := os.ReadFile(namespacesFile)
 		if err != nil {
-			panic(err)
+			errorExit(err)
 		}
 		for idx, line := range strings.Split(string(data), "\n") {
 			fields := strings.Split(line, " ")
 			if len(fields) > 2 {
-				panic(fmt.Errorf("line %d: too many fields: %s", idx, line))
+				errorExit(fmt.Errorf("line %d: too many fields: %s", idx, line))
 			}
 			namespaceMap[fields[0]] = fields[1]
 		}
@@ -347,7 +375,7 @@
 	if descriptionsFile != "" {
 		data, err := os.ReadFile(descriptionsFile)
 		if err != nil {
-			panic(err)
+			errorExit(err)
 		}
 		for _, line := range strings.Split(string(data), "\n") {
 			if strings.TrimSpace(line) != "" {
@@ -361,12 +389,12 @@
 	for _, dir := range dirs {
 		err = ProcessBuildFlags(dir, namespaceMap)
 		if err != nil {
-			panic(err)
+			errorExit(err)
 		}
 
 		err = ProcessReleaseConfigMap(dir, descriptionMap)
 		if err != nil {
-			panic(err)
+			errorExit(err)
 		}
 	}
 }
diff --git a/cmd/release_config/release_config/main.go b/cmd/release_config/release_config/main.go
index c443257..101dbe3 100644
--- a/cmd/release_config/release_config/main.go
+++ b/cmd/release_config/release_config/main.go
@@ -35,6 +35,7 @@
 	var product string
 	var allMake bool
 	var useBuildVar bool
+	var guard bool
 
 	defaultRelease := os.Getenv("TARGET_RELEASE")
 	if defaultRelease == "" {
@@ -52,6 +53,7 @@
 	flag.BoolVar(&pb, "pb", true, "write artifacts as binary protobuf")
 	flag.BoolVar(&allMake, "all_make", true, "write makefiles for all release configs")
 	flag.BoolVar(&useBuildVar, "use_get_build_var", false, "use get_build_var PRODUCT_RELEASE_CONFIG_MAPS")
+	flag.BoolVar(&guard, "guard", true, "whether to guard with RELEASE_BUILD_FLAGS_IN_PROTOBUF")
 
 	flag.Parse()
 
@@ -70,26 +72,27 @@
 	if err != nil {
 		panic(err)
 	}
-	releaseName := config.Name
 	err = os.MkdirAll(outputDir, 0775)
 	if err != nil {
 		panic(err)
 	}
 
-	if err = config.WritePartitionBuildFlags(outputDir, product, targetRelease); err != nil {
-		panic(err)
-	}
-
-	if allMake {
+	makefilePath := filepath.Join(outputDir, fmt.Sprintf("release_config-%s-%s.mk", product, targetRelease))
+	useProto, ok := config.FlagArtifacts["RELEASE_BUILD_FLAGS_IN_PROTOBUF"]
+	if guard && (!ok || rc_lib.MarshalValue(useProto.Value) == "") {
+		// We were told to guard operation and either we have no build flag, or it is False.
+		// Write an empty file so that release_config.mk will use the old process.
+		os.WriteFile(makefilePath, []byte{}, 0644)
+	} else if allMake {
+		// Write one makefile per release config, using the canonical release name.
 		for k, _ := range configs.ReleaseConfigs {
-			makefilePath := filepath.Join(outputDir, fmt.Sprintf("release_config-%s-%s.mk", product, k))
+			makefilePath = filepath.Join(outputDir, fmt.Sprintf("release_config-%s-%s.mk", product, k))
 			err = configs.WriteMakefile(makefilePath, k)
 			if err != nil {
 				panic(err)
 			}
 		}
 	} else {
-		makefilePath := filepath.Join(outputDir, fmt.Sprintf("release_config-%s-%s.mk", product, releaseName))
 		err = configs.WriteMakefile(makefilePath, targetRelease)
 		if err != nil {
 			panic(err)
@@ -113,4 +116,8 @@
 			panic(err)
 		}
 	}
+	if err = config.WritePartitionBuildFlags(outputDir, product, targetRelease); err != nil {
+		panic(err)
+	}
+
 }
diff --git a/cmd/release_config/release_config_lib/flag_value.go b/cmd/release_config/release_config_lib/flag_value.go
index e155e77..59021e2 100644
--- a/cmd/release_config/release_config_lib/flag_value.go
+++ b/cmd/release_config/release_config_lib/flag_value.go
@@ -52,6 +52,9 @@
 }
 
 func MarshalValue(value *rc_proto.Value) string {
+	if value == nil {
+		return ""
+	}
 	switch val := value.Val.(type) {
 	case *rc_proto.Value_UnspecifiedValue:
 		// Value was never set.
diff --git a/cmd/release_config/release_config_lib/flag_value_test.go b/cmd/release_config/release_config_lib/flag_value_test.go
index aaa4caf..8a98baf 100644
--- a/cmd/release_config/release_config_lib/flag_value_test.go
+++ b/cmd/release_config/release_config_lib/flag_value_test.go
@@ -24,7 +24,7 @@
 	"google.golang.org/protobuf/proto"
 )
 
-type testCaseFlagValue struct {
+type testCaseFlagValueFactory struct {
 	protoPath string
 	name      string
 	data      []byte
@@ -32,14 +32,14 @@
 	err       error
 }
 
-func (tc testCaseFlagValue) assertProtoEqual(t *testing.T, expected, actual proto.Message) {
+func (tc testCaseFlagValueFactory) assertProtoEqual(t *testing.T, expected, actual proto.Message) {
 	if !proto.Equal(expected, actual) {
 		t.Errorf("Expected %q found %q", expected, actual)
 	}
 }
 
-func TestFlagValue(t *testing.T) {
-	testCases := []testCaseFlagValue{
+func TestFlagValueFactory(t *testing.T) {
+	testCases := []testCaseFlagValueFactory{
 		{
 			name:      "stringVal",
 			protoPath: "build/release/flag_values/test/RELEASE_FOO.textproto",
@@ -65,3 +65,50 @@
 		tc.assertProtoEqual(t, &tc.expected, &actual.proto)
 	}
 }
+
+type testCaseMarshalValue struct {
+	name     string
+	value    *rc_proto.Value
+	expected string
+}
+
+func TestMarshalValue(t *testing.T) {
+	testCases := []testCaseMarshalValue{
+		{
+			name:     "nil",
+			value:    nil,
+			expected: "",
+		},
+		{
+			name:     "unspecified",
+			value:    &rc_proto.Value{},
+			expected: "",
+		},
+		{
+			name:     "false",
+			value:    &rc_proto.Value{Val: &rc_proto.Value_BoolValue{false}},
+			expected: "",
+		},
+		{
+			name:     "true",
+			value:    &rc_proto.Value{Val: &rc_proto.Value_BoolValue{true}},
+			expected: "true",
+		},
+		{
+			name:     "string",
+			value:    &rc_proto.Value{Val: &rc_proto.Value_StringValue{"BAR"}},
+			expected: "BAR",
+		},
+		{
+			name:     "obsolete",
+			value:    &rc_proto.Value{Val: &rc_proto.Value_Obsolete{true}},
+			expected: " #OBSOLETE",
+		},
+	}
+	for _, tc := range testCases {
+		actual := MarshalValue(tc.value)
+		if actual != tc.expected {
+			t.Errorf("Expected %q found %q", tc.expected, actual)
+		}
+	}
+}
diff --git a/cmd/release_config/release_config_lib/release_config.go b/cmd/release_config/release_config_lib/release_config.go
index 5996c46..f25cc6e 100644
--- a/cmd/release_config/release_config_lib/release_config.go
+++ b/cmd/release_config/release_config_lib/release_config.go
@@ -62,6 +62,10 @@
 	// The names of release configs that we inherit
 	InheritNames []string
 
+	// True if this release config only allows inheritance and aconfig flag
+	// overrides. Build flag value overrides are an error.
+	AconfigFlagsOnly bool
+
 	// Unmarshalled flag artifacts
 	FlagArtifacts FlagArtifacts
 
@@ -86,7 +90,13 @@
 		if !ok {
 			return fmt.Errorf("Could not inherit flag %s from %s", name, iConfig.Name)
 		}
-		if len(fa.Traces) > 1 {
+		if name == "RELEASE_ACONFIG_VALUE_SETS" {
+			if len(fa.Traces) > 0 {
+				myFa.Traces = append(myFa.Traces, fa.Traces...)
+				myFa.Value = &rc_proto.Value{Val: &rc_proto.Value_StringValue{
+					myFa.Value.GetStringValue() + " " + fa.Value.GetStringValue()}}
+			}
+		} else if len(fa.Traces) > 1 {
 			// A value was assigned. Set our value.
 			myFa.Traces = append(myFa.Traces, fa.Traces[1:]...)
 			myFa.Value = fa.Value
@@ -107,21 +117,7 @@
 
 	// Start with only the flag declarations.
 	config.FlagArtifacts = configs.FlagArtifacts.Clone()
-	// Add RELEASE_ACONFIG_VALUE_SETS
-	workflowManual := rc_proto.Workflow(rc_proto.Workflow_MANUAL)
-	releaseAconfigValueSets := FlagArtifact{
-		FlagDeclaration: &rc_proto.FlagDeclaration{
-			Name:        proto.String("RELEASE_ACONFIG_VALUE_SETS"),
-			Namespace:   proto.String("android_UNKNOWN"),
-			Description: proto.String("Aconfig value sets assembled by release-config"),
-			Workflow:    &workflowManual,
-			Containers:  []string{"system", "system_ext", "product", "vendor"},
-			Value:       &rc_proto.Value{Val: &rc_proto.Value_UnspecifiedValue{false}},
-		},
-		DeclarationIndex: -1,
-		Traces:           []*rc_proto.Tracepoint{},
-	}
-	config.FlagArtifacts["RELEASE_ACONFIG_VALUE_SETS"] = &releaseAconfigValueSets
+	releaseAconfigValueSets := config.FlagArtifacts["RELEASE_ACONFIG_VALUE_SETS"]
 
 	// Generate any configs we need to inherit.  This will detect loops in
 	// the config.
@@ -150,30 +146,28 @@
 	}
 	contributionsToApply = append(contributionsToApply, config.Contributions...)
 
-	myAconfigValueSets := strings.Split(releaseAconfigValueSets.Value.GetStringValue(), " ")
-	myAconfigValueSetsMap := map[string]bool{}
-	for _, v := range myAconfigValueSets {
-		myAconfigValueSetsMap[v] = true
-	}
+	workflowManual := rc_proto.Workflow(rc_proto.Workflow_MANUAL)
 	myDirsMap := make(map[int]bool)
 	for _, contrib := range contributionsToApply {
 		contribAconfigValueSets := []string{}
-		// Gather the aconfig_value_sets from this contribution that are not already in the list.
+		// Gather the aconfig_value_sets from this contribution, allowing duplicates for simplicity.
 		for _, v := range contrib.proto.AconfigValueSets {
-			if _, ok := myAconfigValueSetsMap[v]; !ok {
-				contribAconfigValueSets = append(contribAconfigValueSets, v)
-				myAconfigValueSetsMap[v] = true
-			}
+			contribAconfigValueSets = append(contribAconfigValueSets, v)
 		}
-		myAconfigValueSets = append(myAconfigValueSets, contribAconfigValueSets...)
+		contribAconfigValueSetsString := strings.Join(contribAconfigValueSets, " ")
+		releaseAconfigValueSets.Value = &rc_proto.Value{Val: &rc_proto.Value_StringValue{
+			releaseAconfigValueSets.Value.GetStringValue() + " " + contribAconfigValueSetsString}}
 		releaseAconfigValueSets.Traces = append(
 			releaseAconfigValueSets.Traces,
 			&rc_proto.Tracepoint{
 				Source: proto.String(contrib.path),
-				Value:  &rc_proto.Value{Val: &rc_proto.Value_StringValue{strings.Join(contribAconfigValueSets, " ")}},
+				Value:  &rc_proto.Value{Val: &rc_proto.Value_StringValue{contribAconfigValueSetsString}},
 			})
 
 		myDirsMap[contrib.DeclarationIndex] = true
+		if config.AconfigFlagsOnly && len(contrib.FlagValues) > 0 {
+			return fmt.Errorf("%s does not allow build flag overrides", config.Name)
+		}
 		for _, value := range contrib.FlagValues {
 			name := *value.proto.Name
 			fa, ok := config.FlagArtifacts[name]
@@ -197,6 +191,16 @@
 			}
 		}
 	}
+	// Now remove any duplicates from the actual value of RELEASE_ACONFIG_VALUE_SETS
+	myAconfigValueSets := []string{}
+	myAconfigValueSetsMap := map[string]bool{}
+	for _, v := range strings.Split(releaseAconfigValueSets.Value.GetStringValue(), " ") {
+		if myAconfigValueSetsMap[v] {
+			continue
+		}
+		myAconfigValueSetsMap[v] = true
+		myAconfigValueSets = append(myAconfigValueSets, v)
+	}
 	releaseAconfigValueSets.Value = &rc_proto.Value{Val: &rc_proto.Value_StringValue{strings.TrimSpace(strings.Join(myAconfigValueSets, " "))}}
 
 	directories := []string{}
diff --git a/cmd/release_config/release_config_lib/release_configs.go b/cmd/release_config/release_config_lib/release_configs.go
index 6b47091..3429400 100644
--- a/cmd/release_config/release_config_lib/release_configs.go
+++ b/cmd/release_config/release_config_lib/release_configs.go
@@ -95,7 +95,7 @@
 }
 
 func ReleaseConfigsFactory() (c *ReleaseConfigs) {
-	return &ReleaseConfigs{
+	configs := ReleaseConfigs{
 		Aliases:              make(map[string]*string),
 		FlagArtifacts:        make(map[string]*FlagArtifact),
 		ReleaseConfigs:       make(map[string]*ReleaseConfig),
@@ -103,6 +103,21 @@
 		configDirs:           []string{},
 		configDirIndexes:     make(ReleaseConfigDirMap),
 	}
+	workflowManual := rc_proto.Workflow(rc_proto.Workflow_MANUAL)
+	releaseAconfigValueSets := FlagArtifact{
+		FlagDeclaration: &rc_proto.FlagDeclaration{
+			Name:        proto.String("RELEASE_ACONFIG_VALUE_SETS"),
+			Namespace:   proto.String("android_UNKNOWN"),
+			Description: proto.String("Aconfig value sets assembled by release-config"),
+			Workflow:    &workflowManual,
+			Containers:  []string{"system", "system_ext", "product", "vendor"},
+			Value:       &rc_proto.Value{Val: &rc_proto.Value_UnspecifiedValue{false}},
+		},
+		DeclarationIndex: -1,
+		Traces:           []*rc_proto.Tracepoint{},
+	}
+	configs.FlagArtifacts["RELEASE_ACONFIG_VALUE_SETS"] = &releaseAconfigValueSets
+	return &configs
 }
 
 func ReleaseConfigMapFactory(protoPath string) (m *ReleaseConfigMap) {
@@ -117,9 +132,12 @@
 }
 
 func (configs *ReleaseConfigs) LoadReleaseConfigMap(path string, ConfigDirIndex int) error {
+	if _, err := os.Stat(path); err != nil {
+		return fmt.Errorf("%s does not exist\n", path)
+	}
 	m := ReleaseConfigMapFactory(path)
 	if m.proto.DefaultContainers == nil {
-		return fmt.Errorf("Release config map %s lacks default_container", path)
+		return fmt.Errorf("Release config map %s lacks default_containers", path)
 	}
 	for _, container := range m.proto.DefaultContainers {
 		if !validContainer(container) {
@@ -163,6 +181,9 @@
 		}
 		m.FlagDeclarations = append(m.FlagDeclarations, *flagDeclaration)
 		name := *flagDeclaration.Name
+		if name == "RELEASE_ACONFIG_VALUE_SETS" {
+			return fmt.Errorf("%s: %s is a reserved build flag", path, name)
+		}
 		if def, ok := configs.FlagArtifacts[name]; !ok {
 			configs.FlagArtifacts[name] = &FlagArtifact{FlagDeclaration: flagDeclaration, DeclarationIndex: ConfigDirIndex}
 		} else if !proto.Equal(def.FlagDeclaration, flagDeclaration) {
@@ -173,7 +194,7 @@
 			FlagValue{path: path, proto: rc_proto.FlagValue{
 				Name: proto.String(name), Value: flagDeclaration.Value}})
 		if configs.FlagArtifacts[name].Redacted {
-			return fmt.Errorf("%s may not be redacted by default.", *flagDeclaration.Name)
+			return fmt.Errorf("%s may not be redacted by default.", name)
 		}
 		return nil
 	})
@@ -200,12 +221,18 @@
 			if fmt.Sprintf("%s.textproto", *flagValue.proto.Name) != filepath.Base(path) {
 				return fmt.Errorf("%s incorrectly sets value for flag %s", path, *flagValue.proto.Name)
 			}
+			if *flagValue.proto.Name == "RELEASE_ACONFIG_VALUE_SETS" {
+				return fmt.Errorf("%s: %s is a reserved build flag", path, *flagValue.proto.Name)
+			}
 			releaseConfigContribution.FlagValues = append(releaseConfigContribution.FlagValues, flagValue)
 			return nil
 		})
 		if err2 != nil {
 			return err2
 		}
+		if releaseConfigContribution.proto.GetAconfigFlagsOnly() {
+			config.AconfigFlagsOnly = true
+		}
 		m.ReleaseConfigContributions[name] = releaseConfigContribution
 		config.Contributions = append(config.Contributions, releaseConfigContribution)
 		return nil
@@ -376,7 +403,9 @@
 		if len(releaseConfigMapPaths) == 0 {
 			return nil, fmt.Errorf("No maps found")
 		}
-		fmt.Printf("No --map argument provided.  Using: --map %s\n", strings.Join(releaseConfigMapPaths, " --map "))
+		if !useBuildVar {
+			warnf("No --map argument provided.  Using: --map %s\n", strings.Join(releaseConfigMapPaths, " --map "))
+		}
 	}
 
 	configs := ReleaseConfigsFactory()
@@ -390,6 +419,8 @@
 		mapsRead[configDir] = true
 		configs.configDirIndexes[configDir] = idx
 		configs.configDirs = append(configs.configDirs, configDir)
+		// Force the path to be the textproto path, so that both the scl and textproto formats can coexist.
+		releaseConfigMapPath = filepath.Join(configDir, "release_config_map.textproto")
 		err = configs.LoadReleaseConfigMap(releaseConfigMapPath, idx)
 		if err != nil {
 			return nil, err
diff --git a/cmd/release_config/release_config_lib/util.go b/cmd/release_config/release_config_lib/util.go
index 52a1f85..c0ea789 100644
--- a/cmd/release_config/release_config_lib/util.go
+++ b/cmd/release_config/release_config_lib/util.go
@@ -128,7 +128,7 @@
 
 func warnf(format string, args ...any) (n int, err error) {
 	if !disableWarnings {
-		return fmt.Printf(format, args...)
+		return fmt.Fprintf(os.Stderr, format, args...)
 	}
 	return 0, nil
 }
@@ -164,8 +164,8 @@
 }
 
 // Return the default list of map files to use.
-func GetDefaultMapPaths(queryMaps bool) (defaultLocations StringList, err error) {
-	var defaultMapPaths StringList
+func GetDefaultMapPaths(queryMaps bool) (defaultMapPaths StringList, err error) {
+	var defaultLocations StringList
 	workingDir, err := os.Getwd()
 	if err != nil {
 		return
diff --git a/cmd/release_config/release_config_proto/build_flags_src.pb.go b/cmd/release_config/release_config_proto/build_flags_src.pb.go
index 8054bd9..dded975 100644
--- a/cmd/release_config/release_config_proto/build_flags_src.pb.go
+++ b/cmd/release_config/release_config_proto/build_flags_src.pb.go
@@ -387,6 +387,8 @@
 	// List of names of the aconfig_value_set soong module(s) for this
 	// contribution.
 	AconfigValueSets []string `protobuf:"bytes,3,rep,name=aconfig_value_sets,json=aconfigValueSets" json:"aconfig_value_sets,omitempty"`
+	// Only aconfig flags are allowed in this release config.
+	AconfigFlagsOnly *bool `protobuf:"varint,4,opt,name=aconfig_flags_only,json=aconfigFlagsOnly" json:"aconfig_flags_only,omitempty"`
 }
 
 func (x *ReleaseConfig) Reset() {
@@ -442,6 +444,13 @@
 	return nil
 }
 
+func (x *ReleaseConfig) GetAconfigFlagsOnly() bool {
+	if x != nil && x.AconfigFlagsOnly != nil {
+		return *x.AconfigFlagsOnly
+	}
+	return false
+}
+
 // Any aliases.  These are used for continuous integration builder config.
 type ReleaseAlias struct {
 	state         protoimpl.MessageState
@@ -609,36 +618,39 @@
 	0x67, 0x5f, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x2e, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x52, 0x05, 0x76,
 	0x61, 0x6c, 0x75, 0x65, 0x12, 0x1b, 0x0a, 0x08, 0x72, 0x65, 0x64, 0x61, 0x63, 0x74, 0x65, 0x64,
 	0x18, 0xca, 0x01, 0x20, 0x01, 0x28, 0x08, 0x52, 0x08, 0x72, 0x65, 0x64, 0x61, 0x63, 0x74, 0x65,
-	0x64, 0x22, 0x6e, 0x0a, 0x0e, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x63, 0x6f, 0x6e,
-	0x66, 0x69, 0x67, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28,
-	0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x1a, 0x0a, 0x08, 0x69, 0x6e, 0x68, 0x65, 0x72,
-	0x69, 0x74, 0x73, 0x18, 0x02, 0x20, 0x03, 0x28, 0x09, 0x52, 0x08, 0x69, 0x6e, 0x68, 0x65, 0x72,
-	0x69, 0x74, 0x73, 0x12, 0x2c, 0x0a, 0x12, 0x61, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f, 0x76,
-	0x61, 0x6c, 0x75, 0x65, 0x5f, 0x73, 0x65, 0x74, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x09, 0x52,
-	0x10, 0x61, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x56, 0x61, 0x6c, 0x75, 0x65, 0x53, 0x65, 0x74,
-	0x73, 0x22, 0x3b, 0x0a, 0x0d, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x61, 0x6c, 0x69,
-	0x61, 0x73, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09,
-	0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x16, 0x0a, 0x06, 0x74, 0x61, 0x72, 0x67, 0x65, 0x74,
-	0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x06, 0x74, 0x61, 0x72, 0x67, 0x65, 0x74, 0x22, 0xac,
-	0x01, 0x0a, 0x12, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69,
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-	0x18, 0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x2b, 0x2e, 0x61, 0x6e, 0x64, 0x72, 0x6f, 0x69, 0x64,
-	0x2e, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f,
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-	0x69, 0x61, 0x73, 0x52, 0x07, 0x61, 0x6c, 0x69, 0x61, 0x73, 0x65, 0x73, 0x12, 0x20, 0x0a, 0x0b,
-	0x64, 0x65, 0x73, 0x63, 0x72, 0x69, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x18, 0x02, 0x20, 0x01, 0x28,
-	0x09, 0x52, 0x0b, 0x64, 0x65, 0x73, 0x63, 0x72, 0x69, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x12, 0x2d,
-	0x0a, 0x12, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6c, 0x74, 0x5f, 0x63, 0x6f, 0x6e, 0x74, 0x61, 0x69,
-	0x6e, 0x65, 0x72, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x09, 0x52, 0x11, 0x64, 0x65, 0x66, 0x61,
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-	0x08, 0x77, 0x6f, 0x72, 0x6b, 0x66, 0x6c, 0x6f, 0x77, 0x12, 0x18, 0x0a, 0x14, 0x55, 0x4e, 0x53,
-	0x50, 0x45, 0x43, 0x49, 0x46, 0x49, 0x45, 0x44, 0x5f, 0x77, 0x6f, 0x72, 0x6b, 0x66, 0x6c, 0x6f,
-	0x77, 0x10, 0x00, 0x12, 0x0a, 0x0a, 0x06, 0x4c, 0x41, 0x55, 0x4e, 0x43, 0x48, 0x10, 0x01, 0x12,
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-	0x65, 0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f, 0x70, 0x72, 0x6f, 0x74, 0x6f,
+	0x64, 0x22, 0x9c, 0x01, 0x0a, 0x0e, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x63, 0x6f,
+	0x6e, 0x66, 0x69, 0x67, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01,
+	0x28, 0x09, 0x52, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x1a, 0x0a, 0x08, 0x69, 0x6e, 0x68, 0x65,
+	0x72, 0x69, 0x74, 0x73, 0x18, 0x02, 0x20, 0x03, 0x28, 0x09, 0x52, 0x08, 0x69, 0x6e, 0x68, 0x65,
+	0x72, 0x69, 0x74, 0x73, 0x12, 0x2c, 0x0a, 0x12, 0x61, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f,
+	0x76, 0x61, 0x6c, 0x75, 0x65, 0x5f, 0x73, 0x65, 0x74, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x09,
+	0x52, 0x10, 0x61, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x56, 0x61, 0x6c, 0x75, 0x65, 0x53, 0x65,
+	0x74, 0x73, 0x12, 0x2c, 0x0a, 0x12, 0x61, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f, 0x66, 0x6c,
+	0x61, 0x67, 0x73, 0x5f, 0x6f, 0x6e, 0x6c, 0x79, 0x18, 0x04, 0x20, 0x01, 0x28, 0x08, 0x52, 0x10,
+	0x61, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x46, 0x6c, 0x61, 0x67, 0x73, 0x4f, 0x6e, 0x6c, 0x79,
+	0x22, 0x3b, 0x0a, 0x0d, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x61, 0x6c, 0x69, 0x61,
+	0x73, 0x12, 0x12, 0x0a, 0x04, 0x6e, 0x61, 0x6d, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09, 0x52,
+	0x04, 0x6e, 0x61, 0x6d, 0x65, 0x12, 0x16, 0x0a, 0x06, 0x74, 0x61, 0x72, 0x67, 0x65, 0x74, 0x18,
+	0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x06, 0x74, 0x61, 0x72, 0x67, 0x65, 0x74, 0x22, 0xac, 0x01,
+	0x0a, 0x12, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67,
+	0x5f, 0x6d, 0x61, 0x70, 0x12, 0x45, 0x0a, 0x07, 0x61, 0x6c, 0x69, 0x61, 0x73, 0x65, 0x73, 0x18,
+	0x01, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x2b, 0x2e, 0x61, 0x6e, 0x64, 0x72, 0x6f, 0x69, 0x64, 0x2e,
+	0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f, 0x70,
+	0x72, 0x6f, 0x74, 0x6f, 0x2e, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65, 0x5f, 0x61, 0x6c, 0x69,
+	0x61, 0x73, 0x52, 0x07, 0x61, 0x6c, 0x69, 0x61, 0x73, 0x65, 0x73, 0x12, 0x20, 0x0a, 0x0b, 0x64,
+	0x65, 0x73, 0x63, 0x72, 0x69, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x18, 0x02, 0x20, 0x01, 0x28, 0x09,
+	0x52, 0x0b, 0x64, 0x65, 0x73, 0x63, 0x72, 0x69, 0x70, 0x74, 0x69, 0x6f, 0x6e, 0x12, 0x2d, 0x0a,
+	0x12, 0x64, 0x65, 0x66, 0x61, 0x75, 0x6c, 0x74, 0x5f, 0x63, 0x6f, 0x6e, 0x74, 0x61, 0x69, 0x6e,
+	0x65, 0x72, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x09, 0x52, 0x11, 0x64, 0x65, 0x66, 0x61, 0x75,
+	0x6c, 0x74, 0x43, 0x6f, 0x6e, 0x74, 0x61, 0x69, 0x6e, 0x65, 0x72, 0x73, 0x2a, 0x4a, 0x0a, 0x08,
+	0x77, 0x6f, 0x72, 0x6b, 0x66, 0x6c, 0x6f, 0x77, 0x12, 0x18, 0x0a, 0x14, 0x55, 0x4e, 0x53, 0x50,
+	0x45, 0x43, 0x49, 0x46, 0x49, 0x45, 0x44, 0x5f, 0x77, 0x6f, 0x72, 0x6b, 0x66, 0x6c, 0x6f, 0x77,
+	0x10, 0x00, 0x12, 0x0a, 0x0a, 0x06, 0x4c, 0x41, 0x55, 0x4e, 0x43, 0x48, 0x10, 0x01, 0x12, 0x0c,
+	0x0a, 0x08, 0x50, 0x52, 0x45, 0x42, 0x55, 0x49, 0x4c, 0x54, 0x10, 0x02, 0x12, 0x0a, 0x0a, 0x06,
+	0x4d, 0x41, 0x4e, 0x55, 0x41, 0x4c, 0x10, 0x03, 0x42, 0x33, 0x5a, 0x31, 0x61, 0x6e, 0x64, 0x72,
+	0x6f, 0x69, 0x64, 0x2f, 0x73, 0x6f, 0x6f, 0x6e, 0x67, 0x2f, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73,
+	0x65, 0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x2f, 0x72, 0x65, 0x6c, 0x65, 0x61, 0x73, 0x65,
+	0x5f, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x5f, 0x70, 0x72, 0x6f, 0x74, 0x6f,
 }
 
 var (
diff --git a/cmd/release_config/release_config_proto/build_flags_src.proto b/cmd/release_config/release_config_proto/build_flags_src.proto
index 017e5d4..0ef1a5f 100644
--- a/cmd/release_config/release_config_proto/build_flags_src.proto
+++ b/cmd/release_config/release_config_proto/build_flags_src.proto
@@ -119,6 +119,9 @@
   // List of names of the aconfig_value_set soong module(s) for this
   // contribution.
   repeated string aconfig_value_sets = 3;
+
+  // Only aconfig flags are allowed in this release config.
+  optional bool aconfig_flags_only = 4;
 }
 
 // Any aliases.  These are used for continuous integration builder config.
diff --git a/etc/prebuilt_etc.go b/etc/prebuilt_etc.go
index d1c1d85..025ba27 100644
--- a/etc/prebuilt_etc.go
+++ b/etc/prebuilt_etc.go
@@ -55,6 +55,9 @@
 	ctx.RegisterModuleType("prebuilt_usr_share", PrebuiltUserShareFactory)
 	ctx.RegisterModuleType("prebuilt_usr_share_host", PrebuiltUserShareHostFactory)
 	ctx.RegisterModuleType("prebuilt_usr_hyphendata", PrebuiltUserHyphenDataFactory)
+	ctx.RegisterModuleType("prebuilt_usr_keylayout", PrebuiltUserKeyLayoutFactory)
+	ctx.RegisterModuleType("prebuilt_usr_keychars", PrebuiltUserKeyCharsFactory)
+	ctx.RegisterModuleType("prebuilt_usr_idc", PrebuiltUserIdcFactory)
 	ctx.RegisterModuleType("prebuilt_font", PrebuiltFontFactory)
 	ctx.RegisterModuleType("prebuilt_firmware", PrebuiltFirmwareFactory)
 	ctx.RegisterModuleType("prebuilt_dsp", PrebuiltDSPFactory)
@@ -609,6 +612,39 @@
 	return module
 }
 
+// prebuilt_usr_keylayout is for a prebuilt artifact that is installed in
+// <partition>/usr/keylayout/<sub_dir> directory.
+func PrebuiltUserKeyLayoutFactory() android.Module {
+	module := &PrebuiltEtc{}
+	InitPrebuiltEtcModule(module, "usr/keylayout")
+	// This module is device-only
+	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
+	android.InitDefaultableModule(module)
+	return module
+}
+
+// prebuilt_usr_keychars is for a prebuilt artifact that is installed in
+// <partition>/usr/keychars/<sub_dir> directory.
+func PrebuiltUserKeyCharsFactory() android.Module {
+	module := &PrebuiltEtc{}
+	InitPrebuiltEtcModule(module, "usr/keychars")
+	// This module is device-only
+	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
+	android.InitDefaultableModule(module)
+	return module
+}
+
+// prebuilt_usr_idc is for a prebuilt artifact that is installed in
+// <partition>/usr/idc/<sub_dir> directory.
+func PrebuiltUserIdcFactory() android.Module {
+	module := &PrebuiltEtc{}
+	InitPrebuiltEtcModule(module, "usr/idc")
+	// This module is device-only
+	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
+	android.InitDefaultableModule(module)
+	return module
+}
+
 // prebuilt_font installs a font in <partition>/fonts directory.
 func PrebuiltFontFactory() android.Module {
 	module := &PrebuiltEtc{}
diff --git a/etc/prebuilt_etc_test.go b/etc/prebuilt_etc_test.go
index dd9958c..3ee2340 100644
--- a/etc/prebuilt_etc_test.go
+++ b/etc/prebuilt_etc_test.go
@@ -287,6 +287,48 @@
 	android.AssertPathRelativeToTopEquals(t, "install dir", expected, p.installDirPath)
 }
 
+func TestPrebuiltPrebuiltUserKeyLayoutInstallDirPath(t *testing.T) {
+	result := prepareForPrebuiltEtcTest.RunTestWithBp(t, `
+	prebuilt_usr_keylayout {
+			name: "foo.conf",
+			src: "foo.conf",
+			sub_dir: "bar",
+		}
+	`)
+
+	p := result.Module("foo.conf", "android_arm64_armv8-a").(*PrebuiltEtc)
+	expected := "out/soong/target/product/test_device/system/usr/keylayout/bar"
+	android.AssertPathRelativeToTopEquals(t, "install dir", expected, p.installDirPath)
+}
+
+func TestPrebuiltPrebuiltUserKeyCharsInstallDirPath(t *testing.T) {
+	result := prepareForPrebuiltEtcTest.RunTestWithBp(t, `
+	prebuilt_usr_keychars {
+			name: "foo.conf",
+			src: "foo.conf",
+			sub_dir: "bar",
+		}
+	`)
+
+	p := result.Module("foo.conf", "android_arm64_armv8-a").(*PrebuiltEtc)
+	expected := "out/soong/target/product/test_device/system/usr/keychars/bar"
+	android.AssertPathRelativeToTopEquals(t, "install dir", expected, p.installDirPath)
+}
+
+func TestPrebuiltPrebuiltUserIdcInstallDirPath(t *testing.T) {
+	result := prepareForPrebuiltEtcTest.RunTestWithBp(t, `
+	prebuilt_usr_idc {
+			name: "foo.conf",
+			src: "foo.conf",
+			sub_dir: "bar",
+		}
+	`)
+
+	p := result.Module("foo.conf", "android_arm64_armv8-a").(*PrebuiltEtc)
+	expected := "out/soong/target/product/test_device/system/usr/idc/bar"
+	android.AssertPathRelativeToTopEquals(t, "install dir", expected, p.installDirPath)
+}
+
 func TestPrebuiltFontInstallDirPath(t *testing.T) {
 	result := prepareForPrebuiltEtcTest.RunTestWithBp(t, `
 		prebuilt_font {
diff --git a/genrule/genrule.go b/genrule/genrule.go
index 43f4fe5..4ff82e6 100644
--- a/genrule/genrule.go
+++ b/genrule/genrule.go
@@ -714,13 +714,13 @@
 			rule := getSandboxedRuleBuilder(ctx, android.NewRuleBuilder(pctx, ctx).Sbox(genDir, nil))
 
 			for _, in := range shard {
-				outFile := android.GenPathWithExt(ctx, finalSubDir, in, String(properties.Output_extension))
+				outFile := android.GenPathWithExtAndTrimExt(ctx, finalSubDir, in, String(properties.Output_extension), String(properties.Trim_extension))
 
 				// If sharding is enabled, then outFile is the path to the output file in
 				// the shard directory, and copyTo is the path to the output file in the
 				// final directory.
 				if len(shards) > 1 {
-					shardFile := android.GenPathWithExt(ctx, genSubDir, in, String(properties.Output_extension))
+					shardFile := android.GenPathWithExtAndTrimExt(ctx, genSubDir, in, String(properties.Output_extension), String(properties.Trim_extension))
 					copyTo = append(copyTo, outFile)
 					outFile = shardFile
 				}
@@ -786,6 +786,9 @@
 
 	// Additional files needed for build that are not tooling related.
 	Data []string `android:"path"`
+
+	// Trim the matched extension for each input file, and it should start with ".".
+	Trim_extension *string
 }
 
 const defaultShardSize = 50
diff --git a/genrule/genrule_test.go b/genrule/genrule_test.go
index 2dc6a79..1df887b 100644
--- a/genrule/genrule_test.go
+++ b/genrule/genrule_test.go
@@ -894,6 +894,155 @@
 	)
 }
 
+func TestGenSrcsWithTrimExtAndOutpuExtension(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForGenRuleTest,
+		android.FixtureMergeMockFs(android.MockFS{
+			"external-protos/path/Android.bp": []byte(`
+				filegroup {
+					name: "external-protos",
+					srcs: [
+					    "baz.a.b.c.proto/baz.a.b.c.proto",
+					    "bar.a.b.c.proto",
+					    "qux.ext.a.b.c.proto",
+					],
+				}
+			`),
+			"package-dir/Android.bp": []byte(`
+				gensrcs {
+					name: "module-name",
+					cmd: "mkdir -p $(genDir) && cat $(in) >> $(genDir)/$(out)",
+					srcs: [
+						"src/foo.a.b.c.proto",
+						":external-protos",
+					],
+
+					trim_extension: ".a.b.c.proto",
+					output_extension: "proto.h",
+				}
+			`),
+		}),
+	).RunTest(t)
+
+	exportedIncludeDir := "out/soong/.intermediates/package-dir/module-name/gen/gensrcs"
+	gen := result.Module("module-name", "").(*Module)
+
+	android.AssertPathsRelativeToTopEquals(
+		t,
+		"include path",
+		[]string{exportedIncludeDir},
+		gen.exportedIncludeDirs,
+	)
+	android.AssertPathsRelativeToTopEquals(
+		t,
+		"files",
+		[]string{
+			exportedIncludeDir + "/package-dir/src/foo.proto.h",
+			exportedIncludeDir + "/external-protos/path/baz.a.b.c.proto/baz.proto.h",
+			exportedIncludeDir + "/external-protos/path/bar.proto.h",
+			exportedIncludeDir + "/external-protos/path/qux.ext.proto.h",
+		},
+		gen.outputFiles,
+	)
+}
+
+func TestGenSrcsWithTrimExtButNoOutpuExtension(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForGenRuleTest,
+		android.FixtureMergeMockFs(android.MockFS{
+			"external-protos/path/Android.bp": []byte(`
+				filegroup {
+					name: "external-protos",
+					srcs: [
+					    "baz.a.b.c.proto/baz.a.b.c.proto",
+					    "bar.a.b.c.proto",
+					    "qux.ext.a.b.c.proto",
+					],
+				}
+			`),
+			"package-dir/Android.bp": []byte(`
+				gensrcs {
+					name: "module-name",
+					cmd: "mkdir -p $(genDir) && cat $(in) >> $(genDir)/$(out)",
+					srcs: [
+						"src/foo.a.b.c.proto",
+						":external-protos",
+					],
+
+					trim_extension: ".a.b.c.proto",
+				}
+			`),
+		}),
+	).RunTest(t)
+
+	exportedIncludeDir := "out/soong/.intermediates/package-dir/module-name/gen/gensrcs"
+	gen := result.Module("module-name", "").(*Module)
+
+	android.AssertPathsRelativeToTopEquals(
+		t,
+		"include path",
+		[]string{exportedIncludeDir},
+		gen.exportedIncludeDirs,
+	)
+	android.AssertPathsRelativeToTopEquals(
+		t,
+		"files",
+		[]string{
+			exportedIncludeDir + "/package-dir/src/foo",
+			exportedIncludeDir + "/external-protos/path/baz.a.b.c.proto/baz",
+			exportedIncludeDir + "/external-protos/path/bar",
+			exportedIncludeDir + "/external-protos/path/qux.ext",
+		},
+		gen.outputFiles,
+	)
+}
+
+func TestGenSrcsWithOutpuExtension(t *testing.T) {
+	result := android.GroupFixturePreparers(
+		prepareForGenRuleTest,
+		android.FixtureMergeMockFs(android.MockFS{
+			"external-protos/path/Android.bp": []byte(`
+				filegroup {
+					name: "external-protos",
+					srcs: ["baz/baz.a.b.c.proto", "bar.a.b.c.proto"],
+				}
+			`),
+			"package-dir/Android.bp": []byte(`
+				gensrcs {
+					name: "module-name",
+					cmd: "mkdir -p $(genDir) && cat $(in) >> $(genDir)/$(out)",
+					srcs: [
+						"src/foo.a.b.c.proto",
+						":external-protos",
+					],
+
+					output_extension: "proto.h",
+				}
+			`),
+		}),
+	).RunTest(t)
+
+	exportedIncludeDir := "out/soong/.intermediates/package-dir/module-name/gen/gensrcs"
+	gen := result.Module("module-name", "").(*Module)
+
+	android.AssertPathsRelativeToTopEquals(
+		t,
+		"include path",
+		[]string{exportedIncludeDir},
+		gen.exportedIncludeDirs,
+	)
+	android.AssertPathsRelativeToTopEquals(
+		t,
+		"files",
+		[]string{
+			exportedIncludeDir + "/package-dir/src/foo.a.b.c.proto.h",
+			exportedIncludeDir + "/external-protos/path/baz/baz.a.b.c.proto.h",
+			exportedIncludeDir + "/external-protos/path/bar.a.b.c.proto.h",
+		},
+		gen.outputFiles,
+	)
+}
+
 func TestPrebuiltTool(t *testing.T) {
 	testcases := []struct {
 		name             string
diff --git a/java/classpath_fragment.go b/java/classpath_fragment.go
index 0ebab4d..07bc5c1 100644
--- a/java/classpath_fragment.go
+++ b/java/classpath_fragment.go
@@ -151,10 +151,14 @@
 	return jars
 }
 
+func (c *ClasspathFragmentBase) outputFilename() string {
+	return strings.ToLower(c.classpathType.String()) + ".pb"
+}
+
 func (c *ClasspathFragmentBase) generateClasspathProtoBuildActions(ctx android.ModuleContext, configuredJars android.ConfiguredJarList, jars []classpathJar) {
 	generateProto := proptools.BoolDefault(c.properties.Generate_classpaths_proto, true)
 	if generateProto {
-		outputFilename := strings.ToLower(c.classpathType.String()) + ".pb"
+		outputFilename := c.outputFilename()
 		c.outputFilepath = android.PathForModuleOut(ctx, outputFilename).OutputPath
 		c.installDirPath = android.PathForModuleInstall(ctx, "etc", "classpaths")
 
@@ -181,6 +185,10 @@
 	android.SetProvider(ctx, ClasspathFragmentProtoContentInfoProvider, classpathProtoInfo)
 }
 
+func (c *ClasspathFragmentBase) installClasspathProto(ctx android.ModuleContext) android.InstallPath {
+	return ctx.InstallFile(c.installDirPath, c.outputFilename(), c.outputFilepath)
+}
+
 func writeClasspathsTextproto(ctx android.ModuleContext, output android.WritablePath, jars []classpathJar) {
 	var content strings.Builder
 
diff --git a/java/droidstubs.go b/java/droidstubs.go
index 08caf91..24caf6f 100644
--- a/java/droidstubs.go
+++ b/java/droidstubs.go
@@ -604,6 +604,11 @@
 	}
 }
 
+// AndroidPlusUpdatableJar is the name of some extra jars added into `module-lib` and
+// `system-server` directories that contain all the APIs provided by the platform and updatable
+// modules because the `android.jar` files do not. See b/337836752.
+const AndroidPlusUpdatableJar = "android-plus-updatable.jar"
+
 func (d *Droidstubs) apiLevelsGenerationFlags(ctx android.ModuleContext, cmd *android.RuleBuilderCommand, stubsType StubsType, apiVersionsXml android.WritablePath) {
 	if len(d.properties.Api_levels_annotations_dirs) == 0 {
 		ctx.PropertyErrorf("api_levels_annotations_dirs",
@@ -648,16 +653,24 @@
 			// Grab the first extensions_dir and we find while scanning ExportedDroiddocDir.deps;
 			// ideally this should be read from prebuiltApis.properties.Extensions_*
 			for _, dep := range t.deps {
+				// Check to see if it matches an extension first.
+				depBase := dep.Base()
 				if extRegex.MatchString(dep.String()) && d.properties.Extensions_info_file != nil {
 					if extensions_dir == "" {
 						extensions_dir = t.dir.String() + "/extensions"
 					}
 					cmd.Implicit(dep)
-				}
-				if dep.Base() == filename {
+				} else if depBase == filename {
+					// Check to see if it matches a dessert release for an SDK, e.g. Android, Car, Wear, etc..
 					cmd.Implicit(dep)
-				}
-				if filename != "android.jar" && dep.Base() == "android.jar" {
+				} else if depBase == AndroidPlusUpdatableJar && d.properties.Extensions_info_file != nil {
+					// The output api-versions.xml has been requested to include information on SDK
+					// extensions. That means it also needs to include
+					// so
+					// The module-lib and system-server directories should use `android-plus-updatable.jar`
+					// instead of `android.jar`. See AndroidPlusUpdatableJar for more information.
+					cmd.Implicit(dep)
+				} else if filename != "android.jar" && depBase == "android.jar" {
 					// Metalava implicitly searches these patterns:
 					//  prebuilts/tools/common/api-versions/android-%/android.jar
 					//  prebuilts/sdk/%/public/android.jar
@@ -675,9 +688,25 @@
 		}
 	})
 
+	// Generate the list of --android-jar-pattern options. The order matters so the first one which
+	// matches will be the one that is used for a specific api level..
 	for _, sdkDir := range sdkDirs {
 		for _, dir := range dirs {
-			cmd.FlagWithArg("--android-jar-pattern ", fmt.Sprintf("%s/%%/%s/%s", dir, sdkDir, filename))
+			addPattern := func(jarFilename string) {
+				cmd.FlagWithArg("--android-jar-pattern ", fmt.Sprintf("%s/%%/%s/%s", dir, sdkDir, jarFilename))
+			}
+
+			if sdkDir == "module-lib" || sdkDir == "system-server" {
+				// The module-lib and system-server android.jars do not include the updatable modules (as
+				// doing so in the source would introduce dependency cycles and the prebuilts have to
+				// match the sources). So, instead an additional `android-plus-updatable.jar` will be used
+				// that does include the updatable modules and this pattern will match that. This pattern
+				// is added in addition to the following pattern to decouple this change from the change
+				// to add the `android-plus-updatable.jar`.
+				addPattern(AndroidPlusUpdatableJar)
+			}
+
+			addPattern(filename)
 		}
 	}
 
@@ -1327,7 +1356,7 @@
 // use a strict naming convention
 var (
 	droidstubsModuleNamingToSdkKind = map[string]android.SdkKind{
-		//public is commented out since the core libraries use public in their java_sdk_library names
+		// public is commented out since the core libraries use public in their java_sdk_library names
 		"intracore":     android.SdkIntraCore,
 		"intra.core":    android.SdkIntraCore,
 		"system_server": android.SdkSystemServer,
diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index 4db426e..b3c9ce5 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -221,6 +221,7 @@
 	// ART and platform boot jars must have a corresponding entry in DEX2OATBOOTCLASSPATH
 	classpathJars := configuredJarListToClasspathJars(ctx, configuredJars, BOOTCLASSPATH, DEX2OATBOOTCLASSPATH)
 	b.classpathFragmentBase().generateClasspathProtoBuildActions(ctx, configuredJars, classpathJars)
+	b.classpathFragmentBase().installClasspathProto(ctx)
 }
 
 func (b *platformBootclasspathModule) configuredJars(ctx android.ModuleContext) android.ConfiguredJarList {
diff --git a/java/systemserver_classpath_fragment.go b/java/systemserver_classpath_fragment.go
index b291e70..bad2cf1 100644
--- a/java/systemserver_classpath_fragment.go
+++ b/java/systemserver_classpath_fragment.go
@@ -69,6 +69,7 @@
 	configuredJars = configuredJars.AppendList(&standaloneConfiguredJars)
 	classpathJars = append(classpathJars, standaloneClasspathJars...)
 	p.classpathFragmentBase().generateClasspathProtoBuildActions(ctx, configuredJars, classpathJars)
+	p.classpathFragmentBase().installClasspathProto(ctx)
 }
 
 func (p *platformSystemServerClasspathModule) configuredJars(ctx android.ModuleContext) android.ConfiguredJarList {
diff --git a/rust/config/global.go b/rust/config/global.go
index ba08560..03333b8 100644
--- a/rust/config/global.go
+++ b/rust/config/global.go
@@ -53,6 +53,9 @@
 		"--color=always",
 		"-Z dylib-lto",
 		"-Z link-native-libraries=no",
+
+		// cfg flag to indicate that we are building in AOSP with Soong
+		"--cfg soong",
 	}
 
 	LinuxHostGlobalLinkFlags = []string{
diff --git a/rust/project_json.go b/rust/project_json.go
index ad9b690..05fc09b 100644
--- a/rust/project_json.go
+++ b/rust/project_json.go
@@ -96,7 +96,7 @@
 		var childId int
 		cInfo, known := singleton.knownCrates[rChild.Name()]
 		if !known {
-			childId, ok = singleton.addCrate(ctx, rChild, make(map[string]int))
+			childId, ok = singleton.addCrate(ctx, rChild)
 			if !ok {
 				return
 			}
@@ -128,7 +128,8 @@
 // addCrate adds a crate to singleton.project.Crates ensuring that required
 // dependencies are also added. It returns the index of the new crate in
 // singleton.project.Crates
-func (singleton *projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule *Module, deps map[string]int) (int, bool) {
+func (singleton *projectGeneratorSingleton) addCrate(ctx android.SingletonContext, rModule *Module) (int, bool) {
+	deps := make(map[string]int)
 	rootModule, err := rModule.compiler.checkedCrateRootPath()
 	if err != nil {
 		return 0, false
@@ -180,7 +181,7 @@
 	if cInfo, ok := singleton.knownCrates[module.Name()]; ok {
 		// If we have a new device variant, override the old one
 		if !cInfo.Device && rModule.Device() {
-			singleton.addCrate(ctx, rModule, cInfo.Deps)
+			singleton.addCrate(ctx, rModule)
 			return
 		}
 		crate := singleton.project.Crates[cInfo.Idx]
@@ -188,7 +189,7 @@
 		singleton.project.Crates[cInfo.Idx] = crate
 		return
 	}
-	singleton.addCrate(ctx, rModule, make(map[string]int))
+	singleton.addCrate(ctx, rModule)
 }
 
 func (singleton *projectGeneratorSingleton) GenerateBuildActions(ctx android.SingletonContext) {
diff --git a/scripts/run-soong-tests-with-go-tools.sh b/scripts/run-soong-tests-with-go-tools.sh
index 93c622e..1fbb1fc 100755
--- a/scripts/run-soong-tests-with-go-tools.sh
+++ b/scripts/run-soong-tests-with-go-tools.sh
@@ -74,6 +74,6 @@
     (cd "$dir";
      eval ${network_jail} -- ${GOROOT}/bin/go build ./...
      eval ${network_jail} -- ${GOROOT}/bin/go test ./...
-     eval ${network_jail} -- ${GOROOT}/bin/go test -race -short ./...
+     eval ${network_jail} -- ${GOROOT}/bin/go test -race -timeout 20m -short ./...
     )
 done
diff --git a/tradefed_modules/test_module_config.go b/tradefed_modules/test_module_config.go
index 9127f67..b2d5631 100644
--- a/tradefed_modules/test_module_config.go
+++ b/tradefed_modules/test_module_config.go
@@ -160,35 +160,17 @@
 
 }
 
-// Any test suites in base should not be repeated in the derived class, except "general-tests".
-// We may restrict derived tests to only be "general-tests" as it doesn't make sense to add a slice
-// of a test to compatibility suite.
+// Ensure at least one test_suite is listed.  Ideally it should be general-tests
+// or device-tests, whichever is listed in base and prefer general-tests if both are listed.
+// However this is not enforced yet.
 //
-// Returns ErrorMessage, false on problems
-// Returns _, true if okay.
+// Returns true if okay and reports errors via ModuleErrorf.
 func (m *testModuleConfigModule) validateTestSuites(ctx android.ModuleContext) bool {
 	if len(m.tradefedProperties.Test_suites) == 0 {
-		ctx.ModuleErrorf("At least one test-suite must be set or this won't run. Use \"general-tests\"")
+		ctx.ModuleErrorf("At least one test-suite must be set or this won't run. Use \"general-tests\" or \"device-tests\"")
 		return false
 	}
 
-	derivedSuites := make(map[string]bool)
-	// See if any suites in base is also in derived (other than general-tests)
-	for _, s := range m.tradefedProperties.Test_suites {
-		if s != "general-tests" {
-			derivedSuites[s] = true
-		}
-	}
-	if len(derivedSuites) == 0 {
-		return true
-	}
-	for _, baseSuite := range m.provider.TestSuites {
-		if derivedSuites[baseSuite] {
-			ctx.ModuleErrorf("TestSuite %s exists in the base, do not add it here", baseSuite)
-			return false
-		}
-	}
-
 	return true
 }
 
diff --git a/tradefed_modules/test_module_config_test.go b/tradefed_modules/test_module_config_test.go
index 6997228..b2049b1 100644
--- a/tradefed_modules/test_module_config_test.go
+++ b/tradefed_modules/test_module_config_test.go
@@ -325,30 +325,6 @@
 		RunTestWithBp(t, badBp)
 }
 
-func TestModuleConfigHostDuplicateTestSuitesGiveErrors(t *testing.T) {
-	badBp := `
-		java_test_host {
-			name: "base",
-                        srcs: ["a.java"],
-                        test_suites: ["general-tests", "some-compat"],
-		}
-
-                test_module_config_host {
-                        name: "derived_test",
-                        base: "base",
-                        exclude_filters: ["android.test.example.devcodelab.DevCodelabTest#testHelloFail"],
-                        include_annotations: ["android.platform.test.annotations.LargeTest"],
-                        test_suites: ["general-tests", "some-compat"],
-                }`
-
-	android.GroupFixturePreparers(
-		java.PrepareForTestWithJavaDefaultModules,
-		android.FixtureRegisterWithContext(RegisterTestModuleConfigBuildComponents),
-	).ExtendWithErrorHandler(
-		android.FixtureExpectsAtLeastOneErrorMatchingPattern("TestSuite some-compat exists in the base")).
-		RunTestWithBp(t, badBp)
-}
-
 func TestTestOnlyProvider(t *testing.T) {
 	t.Parallel()
 	ctx := android.GroupFixturePreparers(