diff --git a/Android.bp b/Android.bp
index 63de015..b1db8e9 100644
--- a/Android.bp
+++ b/Android.bp
@@ -130,3 +130,8 @@
     // Currently, only microdroid can refer to buildinfo.prop
     visibility: ["//packages/modules/Virtualization/microdroid"],
 }
+
+// container for apex_contributions selected using build flags
+all_apex_contributions {
+    name: "all_apex_contributions",
+}
diff --git a/OWNERS b/OWNERS
index c52231e..e5374ed 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,3 +1,4 @@
+# Bug component: 99142
 # This file is included by several other projects as the list of people
 # approving build related projects.
 
diff --git a/aconfig/rust_aconfig_library.go b/aconfig/rust_aconfig_library.go
index de41776..71918dd 100644
--- a/aconfig/rust_aconfig_library.go
+++ b/aconfig/rust_aconfig_library.go
@@ -84,6 +84,7 @@
 func (a *aconfigDecorator) SourceProviderDeps(ctx rust.DepsContext, deps rust.Deps) rust.Deps {
 	deps = a.BaseSourceProvider.SourceProviderDeps(ctx, deps)
 	deps.Rustlibs = append(deps.Rustlibs, "libflags_rust")
+	deps.Rustlibs = append(deps.Rustlibs, "liblazy_static")
 	ctx.AddDependency(ctx.Module(), rustDeclarationsTag, a.Properties.Aconfig_declarations)
 	return deps
 }
diff --git a/aconfig/rust_aconfig_library_test.go b/aconfig/rust_aconfig_library_test.go
index 17385c3..a10da2d 100644
--- a/aconfig/rust_aconfig_library_test.go
+++ b/aconfig/rust_aconfig_library_test.go
@@ -22,6 +22,11 @@
 				crate_name: "flags_rust",
 				srcs: ["lib.rs"],
 			}
+			rust_library {
+				name: "liblazy_static", // test mock
+				crate_name: "lazy_static",
+				srcs: ["src/lib.rs"],
+			}
 			aconfig_declarations {
 				name: "my_aconfig_declarations",
 				package: "com.example.package",
diff --git a/android/apex_contributions.go b/android/apex_contributions.go
index a28ac31..6eaca8b 100644
--- a/android/apex_contributions.go
+++ b/android/apex_contributions.go
@@ -15,6 +15,7 @@
 package android
 
 import (
+	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
@@ -24,6 +25,7 @@
 
 func RegisterApexContributionsBuildComponents(ctx RegistrationContext) {
 	ctx.RegisterModuleType("apex_contributions", apexContributionsFactory)
+	ctx.RegisterSingletonModuleType("all_apex_contributions", allApexContributionsFactory)
 }
 
 type apexContributions struct {
@@ -65,3 +67,109 @@
 // prebuilts selection.
 func (m *apexContributions) GenerateAndroidBuildActions(ctx ModuleContext) {
 }
+
+// A container for apex_contributions.
+// Based on product_config, it will create a dependency on the selected
+// apex_contributions per mainline module
+type allApexContributions struct {
+	SingletonModuleBase
+}
+
+func allApexContributionsFactory() SingletonModule {
+	module := &allApexContributions{}
+	InitAndroidModule(module)
+	return module
+}
+
+type apexContributionsDepTag struct {
+	blueprint.BaseDependencyTag
+}
+
+var (
+	acDepTag = apexContributionsDepTag{}
+)
+
+// Creates a dep to each selected apex_contributions
+func (a *allApexContributions) DepsMutator(ctx BottomUpMutatorContext) {
+	ctx.AddDependency(ctx.Module(), acDepTag, ctx.Config().AllApexContributions()...)
+}
+
+// Set PrebuiltSelectionInfoProvider in post deps phase
+func (a *allApexContributions) SetPrebuiltSelectionInfoProvider(ctx BaseModuleContext) {
+	addContentsToProvider := func(p *PrebuiltSelectionInfoMap, m *apexContributions) {
+		for _, content := range m.Contents() {
+			if !ctx.OtherModuleExists(content) {
+				ctx.ModuleErrorf("%s listed in apex_contributions %s does not exist\n", content, m.Name())
+			}
+			pi := &PrebuiltSelectionInfo{
+				baseModuleName:     RemoveOptionalPrebuiltPrefix(content),
+				selectedModuleName: content,
+				metadataModuleName: m.Name(),
+				apiDomain:          m.ApiDomain(),
+			}
+			p.Add(ctx, pi)
+		}
+	}
+
+	if ctx.Config().Bp2buildMode() { // Skip bp2build
+		return
+	}
+	p := PrebuiltSelectionInfoMap{}
+	ctx.VisitDirectDepsWithTag(acDepTag, func(child Module) {
+		if m, ok := child.(*apexContributions); ok {
+			addContentsToProvider(&p, m)
+		} else {
+			ctx.ModuleErrorf("%s is not an apex_contributions module\n", child.Name())
+		}
+	})
+	ctx.SetProvider(PrebuiltSelectionInfoProvider, p)
+}
+
+// A provider containing metadata about whether source or prebuilt should be used
+// This provider will be used in prebuilt_select mutator to redirect deps
+var PrebuiltSelectionInfoProvider = blueprint.NewMutatorProvider(PrebuiltSelectionInfoMap{}, "prebuilt_select")
+
+// Map of baseModuleName to the selected source or prebuilt
+type PrebuiltSelectionInfoMap map[string]PrebuiltSelectionInfo
+
+// Add a new entry to the map with some validations
+func (pm *PrebuiltSelectionInfoMap) Add(ctx BaseModuleContext, p *PrebuiltSelectionInfo) {
+	if p == nil {
+		return
+	}
+	// Do not allow dups. If the base module (without the prebuilt_) has been added before, raise an exception.
+	if old, exists := (*pm)[p.baseModuleName]; exists {
+		ctx.ModuleErrorf("Cannot use Soong module: %s from apex_contributions: %s because it has been added previously as: %s from apex_contributions: %s\n",
+			p.selectedModuleName, p.metadataModuleName, old.selectedModuleName, old.metadataModuleName,
+		)
+	}
+	(*pm)[p.baseModuleName] = *p
+}
+
+type PrebuiltSelectionInfo struct {
+	// e.g. libc
+	baseModuleName string
+	// e.g. (libc|prebuilt_libc)
+	selectedModuleName string
+	// Name of the apex_contributions module
+	metadataModuleName string
+	// e.g. com.android.runtime
+	apiDomain string
+}
+
+// Returns true if `name` is explicitly requested using one of the selected
+// apex_contributions metadata modules.
+func (p *PrebuiltSelectionInfoMap) IsSelected(baseModuleName, name string) bool {
+	if i, exists := (*p)[baseModuleName]; exists {
+		return i.selectedModuleName == name
+	} else {
+		return false
+	}
+}
+
+// This module type does not have any build actions.
+func (a *allApexContributions) GenerateAndroidBuildActions(ctx ModuleContext) {
+}
+
+func (a *allApexContributions) GenerateSingletonBuildActions(ctx SingletonContext) {
+}
diff --git a/android/config.go b/android/config.go
index c376910..bf0b9de 100644
--- a/android/config.go
+++ b/android/config.go
@@ -2129,3 +2129,41 @@
 	val, ok := c.productVariables.BuildFlags[name]
 	return val, ok
 }
+
+var (
+	mainlineApexContributionBuildFlags = []string{
+		"RELEASE_APEX_CONTRIBUTIONS_ADSERVICES",
+		"RELEASE_APEX_CONTRIBUTIONS_APPSEARCH",
+		"RELEASE_APEX_CONTRIBUTIONS_ART",
+		"RELEASE_APEX_CONTRIBUTIONS_BLUETOOTH",
+		"RELEASE_APEX_CONTRIBUTIONS_CONFIGINFRASTRUCTURE",
+		"RELEASE_APEX_CONTRIBUTIONS_CONNECTIVITY",
+		"RELEASE_APEX_CONTRIBUTIONS_CONSCRYPT",
+		"RELEASE_APEX_CONTRIBUTIONS_CRASHRECOVERY",
+		"RELEASE_APEX_CONTRIBUTIONS_DEVICELOCK",
+		"RELEASE_APEX_CONTRIBUTIONS_HEALTHFITNESS",
+		"RELEASE_APEX_CONTRIBUTIONS_IPSEC",
+		"RELEASE_APEX_CONTRIBUTIONS_MEDIA",
+		"RELEASE_APEX_CONTRIBUTIONS_MEDIAPROVIDER",
+		"RELEASE_APEX_CONTRIBUTIONS_ONDEVICEPERSONALIZATION",
+		"RELEASE_APEX_CONTRIBUTIONS_PERMISSION",
+		"RELEASE_APEX_CONTRIBUTIONS_REMOTEKEYPROVISIONING",
+		"RELEASE_APEX_CONTRIBUTIONS_SCHEDULING",
+		"RELEASE_APEX_CONTRIBUTIONS_SDKEXTENSIONS",
+		"RELEASE_APEX_CONTRIBUTIONS_STATSD",
+		"RELEASE_APEX_CONTRIBUTIONS_UWB",
+		"RELEASE_APEX_CONTRIBUTIONS_WIFI",
+	}
+)
+
+// Returns the list of _selected_ apex_contributions
+// Each mainline module will have one entry in the list
+func (c *config) AllApexContributions() []string {
+	ret := []string{}
+	for _, f := range mainlineApexContributionBuildFlags {
+		if val, exists := c.GetBuildFlag(f); exists && val != "" {
+			ret = append(ret, val)
+		}
+	}
+	return ret
+}
diff --git a/android/module.go b/android/module.go
index 250161f..0d405eb 100644
--- a/android/module.go
+++ b/android/module.go
@@ -3231,6 +3231,8 @@
 		return true
 	} else if tag == licensesTag {
 		return true
+	} else if tag == acDepTag {
+		return true
 	}
 	return false
 }
diff --git a/android/prebuilt.go b/android/prebuilt.go
index e7b7979..91c0aa1 100644
--- a/android/prebuilt.go
+++ b/android/prebuilt.go
@@ -387,7 +387,7 @@
 
 func RegisterPrebuiltsPostDepsMutators(ctx RegisterMutatorsContext) {
 	ctx.BottomUp("prebuilt_source", PrebuiltSourceDepsMutator).Parallel()
-	ctx.TopDown("prebuilt_select", PrebuiltSelectModuleMutator).Parallel()
+	ctx.BottomUp("prebuilt_select", PrebuiltSelectModuleMutator).Parallel()
 	ctx.BottomUp("prebuilt_postdeps", PrebuiltPostDepsMutator).Parallel()
 }
 
@@ -406,6 +406,8 @@
 
 // PrebuiltSourceDepsMutator adds dependencies to the prebuilt module from the
 // corresponding source module, if one exists for the same variant.
+// Add a dependency from the prebuilt to `all_apex_contributions`
+// The metadata will be used for source vs prebuilts selection
 func PrebuiltSourceDepsMutator(ctx BottomUpMutatorContext) {
 	m := ctx.Module()
 	// If this module is a prebuilt, is enabled and has not been renamed to source then add a
@@ -416,6 +418,14 @@
 			ctx.AddReverseDependency(ctx.Module(), PrebuiltDepTag, name)
 			p.properties.SourceExists = true
 		}
+		// Add a dependency from the prebuilt to the `all_apex_contributions`
+		// metadata module
+		// TODO: When all branches contain this singleton module, make this strict
+		// TODO: Add this dependency only for mainline prebuilts and not every prebuilt module
+		if ctx.OtherModuleExists("all_apex_contributions") {
+			ctx.AddDependency(m, acDepTag, "all_apex_contributions")
+		}
+
 	}
 }
 
@@ -435,7 +445,11 @@
 
 // PrebuiltSelectModuleMutator marks prebuilts that are used, either overriding source modules or
 // because the source module doesn't exist.  It also disables installing overridden source modules.
-func PrebuiltSelectModuleMutator(ctx TopDownMutatorContext) {
+//
+// If the visited module is the metadata module `all_apex_contributions`, it sets a
+// provider containing metadata about whether source or prebuilt of mainline modules should be used.
+// This logic was added here to prevent the overhead of creating a new mutator.
+func PrebuiltSelectModuleMutator(ctx BottomUpMutatorContext) {
 	m := ctx.Module()
 	if p := GetEmbeddedPrebuilt(m); p != nil {
 		if p.srcsSupplier == nil && p.srcsPropertyName == "" {
@@ -444,6 +458,17 @@
 		if !p.properties.SourceExists {
 			p.properties.UsePrebuilt = p.usePrebuilt(ctx, nil, m)
 		}
+		// Propagate the provider received from `all_apex_contributions`
+		// to the source module
+		ctx.VisitDirectDepsWithTag(acDepTag, func(am Module) {
+			if ctx.Config().Bp2buildMode() {
+				// This provider key is not applicable in bp2build
+				return
+			}
+			psi := ctx.OtherModuleProvider(am, PrebuiltSelectionInfoProvider).(PrebuiltSelectionInfoMap)
+			ctx.SetProvider(PrebuiltSelectionInfoProvider, psi)
+		})
+
 	} else if s, ok := ctx.Module().(Module); ok {
 		ctx.VisitDirectDepsWithTag(PrebuiltDepTag, func(prebuiltModule Module) {
 			p := GetEmbeddedPrebuilt(prebuiltModule)
@@ -455,6 +480,11 @@
 			}
 		})
 	}
+	// If this is `all_apex_contributions`, set a provider containing
+	// metadata about source vs prebuilts selection
+	if am, ok := m.(*allApexContributions); ok {
+		am.SetPrebuiltSelectionInfoProvider(ctx)
+	}
 }
 
 // PrebuiltPostDepsMutator replaces dependencies on the source module with dependencies on the
@@ -480,9 +510,66 @@
 	}
 }
 
+// A wrapper around PrebuiltSelectionInfoMap.IsSelected with special handling for java_sdk_library
+// java_sdk_library is a macro that creates
+// 1. top-level impl library
+// 2. stub libraries (suffixed with .stubs...)
+//
+// java_sdk_library_import is a macro that creates
+// 1. top-level "impl" library
+// 2. stub libraries (suffixed with .stubs...)
+//
+// the impl of java_sdk_library_import is a "hook" for hiddenapi and dexpreopt processing. It does not have an impl jar, but acts as a shim
+// to provide the jar deapxed from the prebuilt apex
+//
+// isSelected uses `all_apex_contributions` to supersede source vs prebuilts selection of the stub libraries. It does not supersede the
+// selection of the top-level "impl" library so that this hook can work
+//
+// TODO (b/308174306) - Fix this when we need to support multiple prebuilts in main
+func isSelected(psi PrebuiltSelectionInfoMap, m Module) bool {
+	if sdkLibrary, ok := m.(interface{ SdkLibraryName() *string }); ok && sdkLibrary.SdkLibraryName() != nil {
+		sln := proptools.String(sdkLibrary.SdkLibraryName())
+		// This is the top-level library
+		// Do not supersede the existing prebuilts vs source selection mechanisms
+		if sln == m.base().BaseModuleName() {
+			return false
+		}
+
+		// Stub library created by java_sdk_library_import
+		if p := GetEmbeddedPrebuilt(m); p != nil {
+			return psi.IsSelected(sln, PrebuiltNameFromSource(sln))
+		}
+
+		// Stub library created by java_sdk_library
+		return psi.IsSelected(sln, sln)
+	}
+	return psi.IsSelected(m.base().BaseModuleName(), m.Name())
+}
+
 // usePrebuilt returns true if a prebuilt should be used instead of the source module.  The prebuilt
 // will be used if it is marked "prefer" or if the source module is disabled.
-func (p *Prebuilt) usePrebuilt(ctx TopDownMutatorContext, source Module, prebuilt Module) bool {
+func (p *Prebuilt) usePrebuilt(ctx BaseMutatorContext, source Module, prebuilt Module) bool {
+	// Use `all_apex_contributions` for source vs prebuilt selection.
+	psi := PrebuiltSelectionInfoMap{}
+	ctx.VisitDirectDepsWithTag(PrebuiltDepTag, func(am Module) {
+		if ctx.OtherModuleHasProvider(am, PrebuiltSelectionInfoProvider) {
+			psi = ctx.OtherModuleProvider(am, PrebuiltSelectionInfoProvider).(PrebuiltSelectionInfoMap)
+		}
+	})
+
+	// If the source module is explicitly listed in the metadata module, use that
+	if source != nil && isSelected(psi, source) {
+		return false
+	}
+	// If the prebuilt module is explicitly listed in the metadata module, use that
+	if isSelected(psi, prebuilt) {
+		return true
+	}
+
+	// If the baseModuleName could not be found in the metadata module,
+	// fall back to the existing source vs prebuilt selection.
+	// TODO: Drop the fallback mechanisms
+
 	if !ctx.Config().Bp2buildMode() {
 		if p.srcsSupplier != nil && len(p.srcsSupplier(ctx, prebuilt)) == 0 {
 			return false
diff --git a/android/prebuilt_test.go b/android/prebuilt_test.go
index fc47cfd..953258e 100644
--- a/android/prebuilt_test.go
+++ b/android/prebuilt_test.go
@@ -335,6 +335,78 @@
 			prebuilt: []OsType{Android, buildOS},
 		},
 		{
+			name: "apex_contributions supersedes any source preferred via use_source_config_var",
+			modules: `
+				source {
+					name: "bar",
+				}
+
+				prebuilt {
+					name: "bar",
+					use_source_config_var: {config_namespace: "acme", var_name: "use_source"},
+					srcs: ["prebuilt_file"],
+				}
+				apex_contributions {
+					name: "my_mainline_module_contribution",
+					api_domain: "apexfoo",
+					// this metadata module contains prebuilt
+					contents: ["prebuilt_bar"],
+				}
+				all_apex_contributions {
+					name: "all_apex_contributions",
+				}
+				`,
+			preparer: FixtureModifyProductVariables(func(variables FixtureProductVariables) {
+				variables.VendorVars = map[string]map[string]string{
+					"acme": {
+						"use_source": "true",
+					},
+				}
+				variables.BuildFlags = map[string]string{
+					"RELEASE_APEX_CONTRIBUTIONS_ADSERVICES": "my_mainline_module_contribution",
+				}
+			}),
+			// use_source_config_var indicates that source should be used
+			// but this is superseded by `my_mainline_module_contribution`
+			prebuilt: []OsType{Android, buildOS},
+		},
+		{
+			name: "apex_contributions supersedes any prebuilt preferred via use_source_config_var",
+			modules: `
+				source {
+					name: "bar",
+				}
+
+				prebuilt {
+					name: "bar",
+					use_source_config_var: {config_namespace: "acme", var_name: "use_source"},
+					srcs: ["prebuilt_file"],
+				}
+				apex_contributions {
+					name: "my_mainline_module_contribution",
+					api_domain: "apexfoo",
+					// this metadata module contains source
+					contents: ["bar"],
+				}
+				all_apex_contributions {
+					name: "all_apex_contributions",
+				}
+				`,
+			preparer: FixtureModifyProductVariables(func(variables FixtureProductVariables) {
+				variables.VendorVars = map[string]map[string]string{
+					"acme": {
+						"use_source": "false",
+					},
+				}
+				variables.BuildFlags = map[string]string{
+					"RELEASE_APEX_CONTRIBUTIONS_ADSERVICES": "my_mainline_module_contribution",
+				}
+			}),
+			// use_source_config_var indicates that prebuilt should be used
+			// but this is superseded by `my_mainline_module_contribution`
+			prebuilt: nil,
+		},
+		{
 			name: "prebuilt use_source_config_var={acme, use_source} - acme_use_source=true",
 			modules: `
 				source {
@@ -497,7 +569,7 @@
 	}
 }
 
-func testPrebuiltError(t *testing.T, expectedError, bp string) {
+func testPrebuiltErrorWithFixture(t *testing.T, expectedError, bp string, fixture FixturePreparer) {
 	t.Helper()
 	fs := MockFS{
 		"prebuilt_file": nil,
@@ -508,9 +580,15 @@
 		PrepareForTestWithOverrides,
 		fs.AddToFixture(),
 		FixtureRegisterWithContext(registerTestPrebuiltModules),
+		OptionalFixturePreparer(fixture),
 	).
 		ExtendWithErrorHandler(FixtureExpectsAtLeastOneErrorMatchingPattern(expectedError)).
 		RunTestWithBp(t, bp)
+
+}
+
+func testPrebuiltError(t *testing.T, expectedError, bp string) {
+	testPrebuiltErrorWithFixture(t, expectedError, bp, nil)
 }
 
 func TestPrebuiltShouldNotChangePartition(t *testing.T) {
@@ -559,6 +637,7 @@
 	ctx.RegisterModuleType("soong_config_module_type", SoongConfigModuleTypeFactory)
 	ctx.RegisterModuleType("soong_config_string_variable", SoongConfigStringVariableDummyFactory)
 	ctx.RegisterModuleType("soong_config_bool_variable", SoongConfigBoolVariableDummyFactory)
+	RegisterApexContributionsBuildComponents(ctx)
 }
 
 type prebuiltModule struct {
@@ -653,3 +732,33 @@
 	InitOverrideModule(m)
 	return m
 }
+
+func TestPrebuiltErrorCannotListBothSourceAndPrebuiltInContributions(t *testing.T) {
+	selectMainlineModuleContritbutions := GroupFixturePreparers(
+		FixtureModifyProductVariables(func(variables FixtureProductVariables) {
+			variables.BuildFlags = map[string]string{
+				"RELEASE_APEX_CONTRIBUTIONS_ADSERVICES": "my_apex_contributions",
+			}
+		}),
+	)
+	testPrebuiltErrorWithFixture(t, `Cannot use Soong module: prebuilt_foo from apex_contributions: my_apex_contributions because it has been added previously as: foo from apex_contributions: my_apex_contributions`, `
+		source {
+			name: "foo",
+		}
+		prebuilt {
+			name: "foo",
+			srcs: ["prebuilt_file"],
+		}
+		apex_contributions {
+			name: "my_apex_contributions",
+			api_domain: "my_mainline_module",
+			contents: [
+			  "foo",
+			  "prebuilt_foo",
+			],
+		}
+		all_apex_contributions {
+			name: "all_apex_contributions",
+		}
+		`, selectMainlineModuleContritbutions)
+}
diff --git a/android/util_test.go b/android/util_test.go
index 20161e5..699135b 100644
--- a/android/util_test.go
+++ b/android/util_test.go
@@ -811,7 +811,7 @@
 			if !reflect.DeepEqual(slice, testCase.expected) {
 				t.Errorf("expected %#v, got %#v", testCase.expected, slice)
 			}
-			if slice != nil && unsafe.SliceData(testCase.in) == unsafe.SliceData(slice) {
+			if cap(slice) > 0 && unsafe.SliceData(testCase.in) == unsafe.SliceData(slice) {
 				t.Errorf("expected slices to have different backing arrays")
 			}
 		})
diff --git a/apex/apex_test.go b/apex/apex_test.go
index e6581cf..ddb9a40 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -5459,7 +5459,7 @@
 
 	checkBootDexJarPath := func(t *testing.T, ctx *android.TestContext, stem string, bootDexJarPath string) {
 		t.Helper()
-		s := ctx.ModuleForTests("platform-bootclasspath", "android_common")
+		s := ctx.ModuleForTests("dex_bootjars", "android_common")
 		foundLibfooJar := false
 		base := stem + ".jar"
 		for _, output := range s.AllOutputs() {
@@ -5909,8 +5909,8 @@
 	`
 
 		ctx := testDexpreoptWithApexes(t, bp, "", preparer, fragment)
-		checkBootDexJarPath(t, ctx, "libfoo", "out/soong/.intermediates/libfoo/android_common_apex10000/hiddenapi/libfoo.jar")
-		checkBootDexJarPath(t, ctx, "libbar", "out/soong/.intermediates/libbar/android_common_myapex/hiddenapi/libbar.jar")
+		checkBootDexJarPath(t, ctx, "libfoo", "out/soong/.intermediates/my-bootclasspath-fragment/android_common_myapex/hiddenapi-modular/encoded/libfoo.jar")
+		checkBootDexJarPath(t, ctx, "libbar", "out/soong/.intermediates/my-bootclasspath-fragment/android_common_myapex/hiddenapi-modular/encoded/libbar.jar")
 
 		// Verify the correct module jars contribute to the hiddenapi index file.
 		checkHiddenAPIIndexFromClassesInputs(t, ctx, ``)
diff --git a/cc/config/darwin_host.go b/cc/config/darwin_host.go
index 2cabdc8..b789590 100644
--- a/cc/config/darwin_host.go
+++ b/cc/config/darwin_host.go
@@ -79,7 +79,7 @@
 	pctx.VariableFunc("macSdkRoot", func(ctx android.PackageVarContext) string {
 		return getMacTools(ctx).sdkRoot
 	})
-	pctx.StaticVariable("macMinVersion", "10.13")
+	pctx.StaticVariable("macMinVersion", "10.14")
 	pctx.VariableFunc("MacArPath", func(ctx android.PackageVarContext) string {
 		return getMacTools(ctx).arPath
 	})
diff --git a/cmd/soong_ui/main.go b/cmd/soong_ui/main.go
index 34b1589..c94ff07 100644
--- a/cmd/soong_ui/main.go
+++ b/cmd/soong_ui/main.go
@@ -692,9 +692,11 @@
 	}
 
 	ctx.Verbosef("Current file limits: %d soft, %d hard", limits.Cur, limits.Max)
-	if limits.Cur == limits.Max {
-		return
-	}
+
+	// Go 1.21 modifies the file limit but restores the original when
+	// execing subprocesses if it hasn't be overridden.  Call Setrlimit
+	// here even if it doesn't appear to be necessary so that the
+	// syscall package considers it set.
 
 	limits.Cur = limits.Max
 	err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limits)
diff --git a/filesystem/filesystem.go b/filesystem/filesystem.go
index f2efd46..3d49114 100644
--- a/filesystem/filesystem.go
+++ b/filesystem/filesystem.go
@@ -350,13 +350,16 @@
 		addStr("avb_algorithm", algorithm)
 		key := android.PathForModuleSrc(ctx, proptools.String(f.properties.Avb_private_key))
 		addPath("avb_key_path", key)
+		partitionName := proptools.StringDefault(f.properties.Partition_name, f.Name())
+		addStr("partition_name", partitionName)
 		avb_add_hashtree_footer_args := "--do_not_generate_fec"
 		if hashAlgorithm := proptools.String(f.properties.Avb_hash_algorithm); hashAlgorithm != "" {
 			avb_add_hashtree_footer_args += " --hash_algorithm " + hashAlgorithm
 		}
+		securityPatchKey := "com.android.build." + partitionName + ".security_patch"
+		securityPatchValue := ctx.Config().PlatformSecurityPatch()
+		avb_add_hashtree_footer_args += " --prop " + securityPatchKey + ":" + securityPatchValue
 		addStr("avb_add_hashtree_footer_args", avb_add_hashtree_footer_args)
-		partitionName := proptools.StringDefault(f.properties.Partition_name, f.Name())
-		addStr("partition_name", partitionName)
 		addStr("avb_salt", f.salt())
 	}
 
diff --git a/genrule/allowlists.go b/genrule/allowlists.go
index 8617de8..7839308 100644
--- a/genrule/allowlists.go
+++ b/genrule/allowlists.go
@@ -51,7 +51,6 @@
 
 	SandboxingDenyModuleList = []string{
 		// go/keep-sorted start
-		"CompilationTestCases_package-dex-usage",
 		"ControlEnvProxyServerProto_cc",
 		"ControlEnvProxyServerProto_h",
 		"CtsApkVerityTestDebugFiles",
@@ -125,20 +124,6 @@
 		"gles31_only_functions_hdr",
 		"gles3_only_functions_hdr",
 		"hci_packets_python3_gen",
-		"hidl2aidl_test_gen_aidl",
-		"hidl2aidl_translate_cpp_test_gen_headers",
-		"hidl2aidl_translate_cpp_test_gen_src",
-		"hidl2aidl_translate_java_test_gen_src",
-		"hidl2aidl_translate_ndk_test_gen_headers",
-		"hidl2aidl_translate_ndk_test_gen_src",
-		"hidl_cpp_impl_test_gen-headers",
-		"hidl_cpp_impl_test_gen-sources",
-		"hidl_error_test_gen",
-		"hidl_export_test_gen-headers",
-		"hidl_format_test_diff",
-		"hidl_hash_test_gen",
-		"hidl_hash_version_gen",
-		"hidl_java_impl_test_gen",
 		"lib-test-profile-text-protos",
 		"libbssl_sys_src_nostd",
 		"libc_musl_sysroot_bits",
diff --git a/java/config/droidstubs.go b/java/config/droidstubs.go
index 59cee1d..b7aab5a 100644
--- a/java/config/droidstubs.go
+++ b/java/config/droidstubs.go
@@ -24,8 +24,6 @@
 		"--repeat-errors-max 10",
 		"--hide UnresolvedImport",
 		"--hide InvalidNullabilityOverride",
-		// b/223382732
-		"--hide ChangedDefault",
 
 		// Force metalava to ignore classes on the classpath when an API file contains missing classes.
 		// See b/285140653 for more information.
@@ -54,8 +52,6 @@
 		"--hide AnnotationExtraction",
 		// b/222738070
 		"--hide BannedThrow",
-		// b/223382732
-		"--hide ChangedDefault",
 	}
 
 	MetalavaAnnotationsWarningsFlags = strings.Join(metalavaAnnotationsWarningsFlags, " ")
diff --git a/java/dexpreopt_config.go b/java/dexpreopt_config.go
index 29551ef..2bd696c 100644
--- a/java/dexpreopt_config.go
+++ b/java/dexpreopt_config.go
@@ -210,57 +210,18 @@
 	return false
 }
 
-// Apex boot config allows to access build/install paths of apex boot jars without going
-// through the usual trouble of registering dependencies on those modules and extracting build paths
-// from those dependencies.
-type apexBootConfig struct {
-	// A list of apex boot jars.
-	modules android.ConfiguredJarList
-
-	// A list of predefined build paths to apex boot jars. They are configured very early,
-	// before the modules for these jars are processed and the actual paths are generated, and
-	// later on a singleton adds commands to copy actual jars to the predefined paths.
-	dexPaths android.WritablePaths
-
-	// Map from module name (without prebuilt_ prefix) to the predefined build path.
-	dexPathsByModule map[string]android.WritablePath
-
-	// A list of dex locations (a.k.a. on-device paths) to the boot jars.
-	dexLocations []string
-}
-
-var updatableBootConfigKey = android.NewOnceKey("apexBootConfig")
-
-// Returns apex boot config.
-func GetApexBootConfig(ctx android.PathContext) apexBootConfig {
-	return ctx.Config().Once(updatableBootConfigKey, func() interface{} {
-		apexBootJars := dexpreopt.GetGlobalConfig(ctx).ApexBootJars
-		dir := android.PathForOutput(ctx, getDexpreoptDirName(ctx), "apex_bootjars")
-		dexPaths := apexBootJars.BuildPaths(ctx, dir)
-		dexPathsByModuleName := apexBootJars.BuildPathsByModule(ctx, dir)
-
-		dexLocations := apexBootJars.DevicePaths(ctx.Config(), android.Android)
-
-		return apexBootConfig{apexBootJars, dexPaths, dexPathsByModuleName, dexLocations}
-	}).(apexBootConfig)
-}
-
 // Returns a list of paths and a list of locations for the boot jars used in dexpreopt (to be
 // passed in -Xbootclasspath and -Xbootclasspath-locations arguments for dex2oat).
 func bcpForDexpreopt(ctx android.PathContext, withUpdatable bool) (android.WritablePaths, []string) {
-	// Non-updatable boot jars (they are used both in the boot image and in dexpreopt).
 	bootImage := defaultBootImageConfig(ctx)
+	if withUpdatable {
+		bootImage = mainlineBootImageConfig(ctx)
+	}
+
 	dexPaths := bootImage.dexPathsDeps
 	// The dex locations for all Android variants are identical.
 	dexLocations := bootImage.getAnyAndroidVariant().dexLocationsDeps
 
-	if withUpdatable {
-		// Apex boot jars (they are used only in dexpreopt, but not in the boot image).
-		apexBootConfig := GetApexBootConfig(ctx)
-		dexPaths = append(dexPaths, apexBootConfig.dexPaths...)
-		dexLocations = append(dexLocations, apexBootConfig.dexLocations...)
-	}
-
 	return dexPaths, dexLocations
 }
 
diff --git a/java/platform_bootclasspath.go b/java/platform_bootclasspath.go
index 02a2298..0d52614 100644
--- a/java/platform_bootclasspath.go
+++ b/java/platform_bootclasspath.go
@@ -202,8 +202,6 @@
 
 	bootDexJarByModule := b.generateHiddenAPIBuildActions(ctx, b.configuredModules, b.fragments)
 	buildRuleForBootJarsPackageCheck(ctx, bootDexJarByModule)
-
-	b.copyApexBootJarsForAppsDexpreopt(ctx, apexModules)
 }
 
 // Generate classpaths.proto config
@@ -415,10 +413,3 @@
 	// INTERNAL_PLATFORM_HIDDENAPI_FLAGS is used by Make rules in art/ and cts/.
 	ctx.Strict("INTERNAL_PLATFORM_HIDDENAPI_FLAGS", b.hiddenAPIFlagsCSV.String())
 }
-
-// Copy apex module dex jars to their predefined locations. They will be used for dexpreopt for apps.
-func (b *platformBootclasspathModule) copyApexBootJarsForAppsDexpreopt(ctx android.ModuleContext, apexModules []android.Module) {
-	config := GetApexBootConfig(ctx)
-	apexBootDexJarsByModule := extractEncodedDexJarsFromModules(ctx, apexModules)
-	copyBootJarsToPredefinedLocations(ctx, apexBootDexJarsByModule, config.dexPathsByModule)
-}
diff --git a/java/sdk_library_test.go b/java/sdk_library_test.go
index 21f0bab..82f8a4d 100644
--- a/java/sdk_library_test.go
+++ b/java/sdk_library_test.go
@@ -1068,6 +1068,137 @@
 	})
 }
 
+// If a module is listed in `mainline_module_contributions, it should be used
+// It will supersede any other source vs prebuilt selection mechanism like `prefer` attribute
+func TestSdkLibraryImport_MetadataModuleSupersedesPreferred(t *testing.T) {
+	bp := `
+		apex_contributions {
+			name: "my_mainline_module_contributions",
+			api_domain: "my_mainline_module",
+			contents: [
+				// legacy mechanism prefers the prebuilt
+				// mainline_module_contributions supersedes this since source is listed explicitly
+				"sdklib.prebuilt_preferred_using_legacy_flags",
+
+				// legacy mechanism prefers the source
+				// mainline_module_contributions supersedes this since prebuilt is listed explicitly
+				"prebuilt_sdklib.source_preferred_using_legacy_flags",
+			],
+		}
+		all_apex_contributions {
+			name: "all_apex_contributions",
+		}
+		java_sdk_library {
+			name: "sdklib.prebuilt_preferred_using_legacy_flags",
+			srcs: ["a.java"],
+			sdk_version: "none",
+			system_modules: "none",
+			public: {
+				enabled: true,
+			},
+			system: {
+				enabled: true,
+			}
+		}
+		java_sdk_library_import {
+			name: "sdklib.prebuilt_preferred_using_legacy_flags",
+			prefer: true, // prebuilt is preferred using legacy mechanism
+			public: {
+				jars: ["a.jar"],
+				stub_srcs: ["a.java"],
+				current_api: "current.txt",
+				removed_api: "removed.txt",
+				annotations: "annotations.zip",
+			},
+			system: {
+				jars: ["a.jar"],
+				stub_srcs: ["a.java"],
+				current_api: "current.txt",
+				removed_api: "removed.txt",
+				annotations: "annotations.zip",
+			},
+		}
+		java_sdk_library {
+			name: "sdklib.source_preferred_using_legacy_flags",
+			srcs: ["a.java"],
+			sdk_version: "none",
+			system_modules: "none",
+			public: {
+				enabled: true,
+			},
+			system: {
+				enabled: true,
+			}
+		}
+		java_sdk_library_import {
+			name: "sdklib.source_preferred_using_legacy_flags",
+			prefer: false, // source is preferred using legacy mechanism
+			public: {
+				jars: ["a.jar"],
+				stub_srcs: ["a.java"],
+				current_api: "current.txt",
+				removed_api: "removed.txt",
+				annotations: "annotations.zip",
+			},
+			system: {
+				jars: ["a.jar"],
+				stub_srcs: ["a.java"],
+				current_api: "current.txt",
+				removed_api: "removed.txt",
+				annotations: "annotations.zip",
+			},
+		}
+
+		// rdeps
+		java_library {
+			name: "public",
+			srcs: ["a.java"],
+			libs: [
+				// this should get source since source is listed in my_mainline_module_contributions
+				"sdklib.prebuilt_preferred_using_legacy_flags.stubs",
+				"sdklib.prebuilt_preferred_using_legacy_flags.stubs.system",
+
+				// this should get prebuilt since source is listed in my_mainline_module_contributions
+				"sdklib.source_preferred_using_legacy_flags.stubs",
+				"sdklib.source_preferred_using_legacy_flags.stubs.system",
+
+			],
+		}
+	`
+	result := android.GroupFixturePreparers(
+		prepareForJavaTest,
+		PrepareForTestWithJavaSdkLibraryFiles,
+		FixtureWithLastReleaseApis("sdklib.source_preferred_using_legacy_flags", "sdklib.prebuilt_preferred_using_legacy_flags"),
+		android.FixtureRegisterWithContext(func(ctx android.RegistrationContext) {
+			android.RegisterApexContributionsBuildComponents(ctx)
+		}),
+		android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
+			variables.BuildFlags = map[string]string{
+				"RELEASE_APEX_CONTRIBUTIONS_ADSERVICES": "my_mainline_module_contributions",
+			}
+		}),
+	).RunTestWithBp(t, bp)
+
+	// Make sure that rdeps get the correct source vs prebuilt based on mainline_module_contributions
+	public := result.ModuleForTests("public", "android_common")
+	rule := public.Output("javac/public.jar")
+	inputs := rule.Implicits.Strings()
+	expectedInputs := []string{
+		// source
+		"out/soong/.intermediates/sdklib.prebuilt_preferred_using_legacy_flags.stubs/android_common/turbine-combined/sdklib.prebuilt_preferred_using_legacy_flags.stubs.jar",
+		"out/soong/.intermediates/sdklib.prebuilt_preferred_using_legacy_flags.stubs.system/android_common/turbine-combined/sdklib.prebuilt_preferred_using_legacy_flags.stubs.system.jar",
+
+		// prebuilt
+		"out/soong/.intermediates/prebuilt_sdklib.source_preferred_using_legacy_flags.stubs/android_common/combined/sdklib.source_preferred_using_legacy_flags.stubs.jar",
+		"out/soong/.intermediates/prebuilt_sdklib.source_preferred_using_legacy_flags.stubs.system/android_common/combined/sdklib.source_preferred_using_legacy_flags.stubs.system.jar",
+	}
+	for _, expected := range expectedInputs {
+		if !android.InList(expected, inputs) {
+			t.Errorf("expected %q to contain %q", inputs, expected)
+		}
+	}
+}
+
 func TestJavaSdkLibraryEnforce(t *testing.T) {
 	partitionToBpOption := func(partition string) string {
 		switch partition {
diff --git a/scripts/conv_linker_config.py b/scripts/conv_linker_config.py
index c6e6e30..ed3fbb7 100644
--- a/scripts/conv_linker_config.py
+++ b/scripts/conv_linker_config.py
@@ -149,6 +149,11 @@
     else:
         sys.exit(f'Unknown type: {args.type}')
 
+    # Reject contributions field at build time while keeping the runtime behavior for GRF.
+    if getattr(pb, 'contributions'):
+        sys.exit(f"{args.input}: 'contributions' is set. "
+                 "It's deprecated. Instead, make the APEX 'visible' and use android_dlopen_ext().")
+
 
 def ValidateAndWriteAsPbFile(pb, output_path):
     ValidateConfiguration(pb)