diff --git a/android/config.go b/android/config.go
index 8c5f6e36d..839ff05c3 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1645,10 +1645,6 @@ func (c *config) AmlAbis() bool {
 	return Bool(c.productVariables.Aml_abis)
 }
 
-func (c *config) FlattenApex() bool {
-	return Bool(c.productVariables.Flatten_apex)
-}
-
 func (c *config) ForceApexSymlinkOptimization() bool {
 	return Bool(c.productVariables.ForceApexSymlinkOptimization)
 }
diff --git a/android/variable.go b/android/variable.go
index 00315bc1a..3bec854ea 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -175,10 +175,6 @@ type variableProperties struct {
 			Whole_static_libs []string `android:"arch_variant"`
 		} `android:"arch_variant"`
 
-		Flatten_apex struct {
-			Enabled *bool
-		}
-
 		Native_coverage struct {
 			Src          *string  `android:"arch_variant"`
 			Srcs         []string `android:"arch_variant"`
@@ -397,7 +393,6 @@ type productVariables struct {
 	Ndk_abis *bool `json:",omitempty"`
 
 	TrimmedApex                  *bool `json:",omitempty"`
-	Flatten_apex                 *bool `json:",omitempty"`
 	ForceApexSymlinkOptimization *bool `json:",omitempty"`
 	CompressedApex               *bool `json:",omitempty"`
 	Aml_abis                     *bool `json:",omitempty"`
diff --git a/apex/androidmk.go b/apex/androidmk.go
index 684833de4..f4690620c 100644
--- a/apex/androidmk.go
+++ b/apex/androidmk.go
@@ -85,16 +85,12 @@ func (a *apexBundle) androidMkForFiles(w io.Writer, apexBundleName, moduleDir st
 	// conflicts between two apexes with the same apexName.
 
 	moduleNames := []string{}
-	apexType := a.properties.ApexType
 	// To avoid creating duplicate build rules, run this function only when primaryApexType is true
 	// to install symbol files in $(PRODUCT_OUT}/apex.
-	// And if apexType is flattened, run this function to install files in $(PRODUCT_OUT}/system/apex.
-	if !a.primaryApexType && apexType != flattenedApex {
+	if !a.primaryApexType {
 		return moduleNames
 	}
 
-	seenDataOutPaths := make(map[string]bool)
-
 	for _, fi := range a.filesInfo {
 		linkToSystemLib := a.linkToSystemLib && fi.transitiveDep && fi.availableToPlatform()
 		moduleName := a.fullModuleName(apexBundleName, linkToSystemLib, &fi)
@@ -131,33 +127,13 @@ func (a *apexBundle) androidMkForFiles(w io.Writer, apexBundleName, moduleDir st
 		}
 		// /apex/<apexBundleName>/{lib|framework|...}
 		pathForSymbol := filepath.Join("$(PRODUCT_OUT)", "apex", apexBundleName, fi.installDir)
-		var modulePath string
-		if apexType == flattenedApex {
-			// /system/apex/<apexBundleName>/{lib|framework|...}
-			modulePath = filepath.Join(a.installDir.String(), apexBundleName, fi.installDir)
-			fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", modulePath)
-			if a.primaryApexType {
-				fmt.Fprintln(w, "LOCAL_SOONG_SYMBOL_PATH :=", pathForSymbol)
-			}
-			android.AndroidMkEmitAssignList(w, "LOCAL_MODULE_SYMLINKS", fi.symlinks)
-			newDataPaths := []android.DataPath{}
-			for _, path := range fi.dataPaths {
-				dataOutPath := modulePath + ":" + path.SrcPath.Rel()
-				if ok := seenDataOutPaths[dataOutPath]; !ok {
-					newDataPaths = append(newDataPaths, path)
-					seenDataOutPaths[dataOutPath] = true
-				}
-			}
-			android.AndroidMkEmitAssignList(w, "LOCAL_TEST_DATA", android.AndroidMkDataPaths(newDataPaths))
-		} else {
-			modulePath = pathForSymbol
-			fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", modulePath)
+		modulePath := pathForSymbol
+		fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", modulePath)
 
-			// For non-flattend APEXes, the merged notice file is attached to the APEX itself.
-			// We don't need to have notice file for the individual modules in it. Otherwise,
-			// we will have duplicated notice entries.
-			fmt.Fprintln(w, "LOCAL_NO_NOTICE_FILE := true")
-		}
+		// For non-flattend APEXes, the merged notice file is attached to the APEX itself.
+		// We don't need to have notice file for the individual modules in it. Otherwise,
+		// we will have duplicated notice entries.
+		fmt.Fprintln(w, "LOCAL_NO_NOTICE_FILE := true")
 		fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", filepath.Join(modulePath, fi.stem()))
 		fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", fi.builtFile.String()+":"+filepath.Join(modulePath, fi.stem()))
 		fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", fi.builtFile.String())
@@ -257,31 +233,6 @@ func (a *apexBundle) androidMkForFiles(w io.Writer, apexBundleName, moduleDir st
 			fmt.Fprintln(w, "include $(BUILD_SYSTEM)/soong_cc_rust_prebuilt.mk")
 		default:
 			fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", fi.stem())
-			if fi.builtFile == a.manifestPbOut && apexType == flattenedApex {
-				if a.primaryApexType {
-					// To install companion files (init_rc, vintf_fragments)
-					// Copy some common properties of apexBundle to apex_manifest
-					commonProperties := []string{
-						"LOCAL_FULL_INIT_RC", "LOCAL_FULL_VINTF_FRAGMENTS",
-					}
-					for _, name := range commonProperties {
-						if value, ok := apexAndroidMkData.Entries.EntryMap[name]; ok {
-							android.AndroidMkEmitAssignList(w, name, value)
-						}
-					}
-
-					// Make apex_manifest.pb module for this APEX to override all other
-					// modules in the APEXes being overridden by this APEX
-					var patterns []string
-					for _, o := range a.overridableProperties.Overrides {
-						patterns = append(patterns, "%."+o+a.suffix)
-					}
-					android.AndroidMkEmitAssignList(w, "LOCAL_OVERRIDES_MODULES", patterns)
-				}
-
-				// File_contexts of flattened APEXes should be merged into file_contexts.bin
-				fmt.Fprintln(w, "LOCAL_FILE_CONTEXTS :=", a.fileContexts)
-			}
 			fmt.Fprintln(w, "include $(BUILD_PREBUILT)")
 		}
 
@@ -320,73 +271,62 @@ func (a *apexBundle) androidMkForType() android.AndroidMkData {
 				moduleNames = a.androidMkForFiles(w, name, moduleDir, data)
 			}
 
-			if apexType == flattenedApex {
-				// Only image APEXes can be flattened.
-				fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)  # apex.apexBundle.flat")
-				fmt.Fprintln(w, "LOCAL_PATH :=", moduleDir)
-				fmt.Fprintln(w, "LOCAL_MODULE :=", name+a.suffix)
-				data.Entries.WriteLicenseVariables(w)
-				a.writeRequiredModules(w, moduleNames)
-				fmt.Fprintln(w, "include $(BUILD_PHONY_PACKAGE)")
-
-			} else {
-				fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)  # apex.apexBundle")
-				fmt.Fprintln(w, "LOCAL_PATH :=", moduleDir)
-				fmt.Fprintln(w, "LOCAL_MODULE :=", name+a.suffix)
-				data.Entries.WriteLicenseVariables(w)
-				fmt.Fprintln(w, "LOCAL_MODULE_CLASS := ETC") // do we need a new class?
-				fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", a.outputFile.String())
-				fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", a.installDir.String())
-				stemSuffix := apexType.suffix()
-				if a.isCompressed {
-					stemSuffix = imageCapexSuffix
-				}
-				fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+stemSuffix)
-				fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
-				if a.installable() {
-					fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", a.installedFile.String())
-					fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", a.outputFile.String()+":"+a.installedFile.String())
-				}
-
-				// Because apex writes .mk with Custom(), we need to write manually some common properties
-				// which are available via data.Entries
-				commonProperties := []string{
-					"LOCAL_FULL_INIT_RC", "LOCAL_FULL_VINTF_FRAGMENTS",
-					"LOCAL_PROPRIETARY_MODULE", "LOCAL_VENDOR_MODULE", "LOCAL_ODM_MODULE", "LOCAL_PRODUCT_MODULE", "LOCAL_SYSTEM_EXT_MODULE",
-					"LOCAL_MODULE_OWNER",
-				}
-				for _, name := range commonProperties {
-					if value, ok := data.Entries.EntryMap[name]; ok {
-						android.AndroidMkEmitAssignList(w, name, value)
-					}
-				}
-
-				android.AndroidMkEmitAssignList(w, "LOCAL_OVERRIDES_MODULES", a.overridableProperties.Overrides)
-				a.writeRequiredModules(w, moduleNames)
-
-				fmt.Fprintln(w, "include $(BUILD_PREBUILT)")
-
-				if apexType == imageApex {
-					fmt.Fprintln(w, "ALL_MODULES.$(my_register_name).BUNDLE :=", a.bundleModuleFile.String())
-				}
-				android.AndroidMkEmitAssignList(w, "ALL_MODULES.$(my_register_name).LINT_REPORTS", a.lintReports.Strings())
-
-				if a.installedFilesFile != nil {
-					goal := "checkbuild"
-					distFile := name + "-installed-files.txt"
-					fmt.Fprintln(w, ".PHONY:", goal)
-					fmt.Fprintf(w, "$(call dist-for-goals,%s,%s:%s)\n",
-						goal, a.installedFilesFile.String(), distFile)
-					fmt.Fprintf(w, "$(call declare-0p-target,%s)\n", a.installedFilesFile.String())
-				}
-				for _, dist := range data.Entries.GetDistForGoals(a) {
-					fmt.Fprintf(w, dist)
-				}
-
-				distCoverageFiles(w, "ndk_apis_usedby_apex", a.nativeApisUsedByModuleFile.String())
-				distCoverageFiles(w, "ndk_apis_backedby_apex", a.nativeApisBackedByModuleFile.String())
-				distCoverageFiles(w, "java_apis_used_by_apex", a.javaApisUsedByModuleFile.String())
+			fmt.Fprintln(w, "\ninclude $(CLEAR_VARS)  # apex.apexBundle")
+			fmt.Fprintln(w, "LOCAL_PATH :=", moduleDir)
+			fmt.Fprintln(w, "LOCAL_MODULE :=", name+a.suffix)
+			data.Entries.WriteLicenseVariables(w)
+			fmt.Fprintln(w, "LOCAL_MODULE_CLASS := ETC") // do we need a new class?
+			fmt.Fprintln(w, "LOCAL_PREBUILT_MODULE_FILE :=", a.outputFile.String())
+			fmt.Fprintln(w, "LOCAL_MODULE_PATH :=", a.installDir.String())
+			stemSuffix := apexType.suffix()
+			if a.isCompressed {
+				stemSuffix = imageCapexSuffix
 			}
+			fmt.Fprintln(w, "LOCAL_MODULE_STEM :=", name+stemSuffix)
+			fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE :=", !a.installable())
+			if a.installable() {
+				fmt.Fprintln(w, "LOCAL_SOONG_INSTALLED_MODULE :=", a.installedFile.String())
+				fmt.Fprintln(w, "LOCAL_SOONG_INSTALL_PAIRS :=", a.outputFile.String()+":"+a.installedFile.String())
+			}
+
+			// Because apex writes .mk with Custom(), we need to write manually some common properties
+			// which are available via data.Entries
+			commonProperties := []string{
+				"LOCAL_FULL_INIT_RC", "LOCAL_FULL_VINTF_FRAGMENTS",
+				"LOCAL_PROPRIETARY_MODULE", "LOCAL_VENDOR_MODULE", "LOCAL_ODM_MODULE", "LOCAL_PRODUCT_MODULE", "LOCAL_SYSTEM_EXT_MODULE",
+				"LOCAL_MODULE_OWNER",
+			}
+			for _, name := range commonProperties {
+				if value, ok := data.Entries.EntryMap[name]; ok {
+					android.AndroidMkEmitAssignList(w, name, value)
+				}
+			}
+
+			android.AndroidMkEmitAssignList(w, "LOCAL_OVERRIDES_MODULES", a.overridableProperties.Overrides)
+			a.writeRequiredModules(w, moduleNames)
+
+			fmt.Fprintln(w, "include $(BUILD_PREBUILT)")
+
+			if apexType == imageApex {
+				fmt.Fprintln(w, "ALL_MODULES.$(my_register_name).BUNDLE :=", a.bundleModuleFile.String())
+			}
+			android.AndroidMkEmitAssignList(w, "ALL_MODULES.$(my_register_name).LINT_REPORTS", a.lintReports.Strings())
+
+			if a.installedFilesFile != nil {
+				goal := "checkbuild"
+				distFile := name + "-installed-files.txt"
+				fmt.Fprintln(w, ".PHONY:", goal)
+				fmt.Fprintf(w, "$(call dist-for-goals,%s,%s:%s)\n",
+					goal, a.installedFilesFile.String(), distFile)
+				fmt.Fprintf(w, "$(call declare-0p-target,%s)\n", a.installedFilesFile.String())
+			}
+			for _, dist := range data.Entries.GetDistForGoals(a) {
+				fmt.Fprintf(w, dist)
+			}
+
+			distCoverageFiles(w, "ndk_apis_usedby_apex", a.nativeApisUsedByModuleFile.String())
+			distCoverageFiles(w, "ndk_apis_backedby_apex", a.nativeApisBackedByModuleFile.String())
+			distCoverageFiles(w, "java_apis_used_by_apex", a.javaApisUsedByModuleFile.String())
 		}}
 }
 
diff --git a/apex/apex.go b/apex/apex.go
index 51c67d004..1d094eb31 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -79,7 +79,7 @@ func RegisterPostDepsMutators(ctx android.RegisterMutatorsContext) {
 	ctx.BottomUp("mark_platform_availability", markPlatformAvailability).Parallel()
 	ctx.BottomUp("apex", apexMutator).Parallel()
 	ctx.BottomUp("apex_directly_in_any", apexDirectlyInAnyMutator).Parallel()
-	ctx.BottomUp("apex_flattened", apexFlattenedMutator).Parallel()
+	ctx.BottomUp("apex_packaging", apexPackagingMutator).Parallel()
 	ctx.BottomUp("apex_dcla_deps", apexDCLADepsMutator).Parallel()
 	// Register after apex_info mutator so that it can use ApexVariationName
 	ctx.TopDown("apex_strict_updatability_lint", apexStrictUpdatibilityLintMutator).Parallel()
@@ -216,9 +216,7 @@ type apexBundleProperties struct {
 
 	HideFromMake bool `blueprint:"mutated"`
 
-	// Internal package method for this APEX. When payload_type is image, this can be either
-	// imageApex or flattenedApex depending on Config.FlattenApex(). When payload_type is zip,
-	// this becomes zipApex.
+	// Internal package method for this APEX.
 	ApexType apexPackaging `blueprint:"mutated"`
 
 	// Name that dependencies can specify in their apex_available properties to refer to this module.
@@ -427,7 +425,7 @@ type apexBundle struct {
 	// one gets installed to the device.
 	primaryApexType bool
 
-	// Suffix of module name in Android.mk ".flattened", ".apex", ".zipapex", or ""
+	// Suffix of module name in Android.mk ".apex", ".zipapex", or ""
 	suffix string
 
 	// File system type of apex_payload.img
@@ -535,8 +533,7 @@ var (
 // apexFile represents a file in an APEX bundle. This is created during the first half of
 // GenerateAndroidBuildActions by traversing the dependencies of the APEX. Then in the second half
 // of the function, this is used to create commands that copies the files into a staging directory,
-// where they are packaged into the APEX file. This struct is also used for creating Make modules
-// for each of the files in case when the APEX is flattened.
+// where they are packaged into the APEX file.
 type apexFile struct {
 	// buildFile is put in the installDir inside the APEX.
 	builtFile  android.Path
@@ -1367,12 +1364,8 @@ const (
 	// zipApex is a packaging method where contents are directly included in the zip container.
 	// This is used for host-side testing - because the contents are easily accessible by
 	// unzipping the container.
+	// TODO(b/279835185) deprecate zipApex
 	zipApex
-
-	// flattendApex is a packaging method where contents are not included in the APEX file, but
-	// installed to /apex/<apexname> directory on the device. This packaging method is used for
-	// old devices where the filesystem-based APEX file can't be supported.
-	flattenedApex
 )
 
 const (
@@ -1380,12 +1373,10 @@ const (
 	imageApexSuffix  = ".apex"
 	imageCapexSuffix = ".capex"
 	zipApexSuffix    = ".zipapex"
-	flattenedSuffix  = ".flattened"
 
 	// variant names each of which is for a packaging method
-	imageApexType     = "image"
-	zipApexType       = "zip"
-	flattenedApexType = "flattened"
+	imageApexType = "image"
+	zipApexType   = "zip"
 
 	ext4FsType  = "ext4"
 	f2fsFsType  = "f2fs"
@@ -1415,9 +1406,8 @@ func (a apexPackaging) name() string {
 	}
 }
 
-// apexFlattenedMutator creates one or more variations each of which is for a packaging method.
-// TODO(jiyong): give a better name to this mutator
-func apexFlattenedMutator(mctx android.BottomUpMutatorContext) {
+// apexPackagingMutator creates one or more variations each of which is for a packaging method.
+func apexPackagingMutator(mctx android.BottomUpMutatorContext) {
 	if !mctx.Module().Enabled() {
 		return
 	}
@@ -1425,19 +1415,11 @@ func apexFlattenedMutator(mctx android.BottomUpMutatorContext) {
 		var variants []string
 		switch proptools.StringDefault(ab.properties.Payload_type, "image") {
 		case "image":
-			// This is the normal case. Note that both image and flattend APEXes are
-			// created. The image type is installed to the system partition, while the
-			// flattened APEX is (optionally) installed to the system_ext partition.
-			// This is mostly for GSI which has to support wide range of devices. If GSI
-			// is installed on a newer (APEX-capable) device, the image APEX in the
-			// system will be used. However, if the same GSI is installed on an old
-			// device which can't support image APEX, the flattened APEX in the
-			// system_ext partion (which still is part of GSI) is used instead.
-			variants = append(variants, imageApexType, flattenedApexType)
+			variants = append(variants, imageApexType)
 		case "zip":
 			variants = append(variants, zipApexType)
 		case "both":
-			variants = append(variants, imageApexType, zipApexType, flattenedApexType)
+			variants = append(variants, imageApexType, zipApexType)
 		default:
 			mctx.PropertyErrorf("payload_type", "%q is not one of \"image\", \"zip\", or \"both\".", *ab.properties.Payload_type)
 			return
@@ -1451,18 +1433,12 @@ func apexFlattenedMutator(mctx android.BottomUpMutatorContext) {
 				modules[i].(*apexBundle).properties.ApexType = imageApex
 			case zipApexType:
 				modules[i].(*apexBundle).properties.ApexType = zipApex
-			case flattenedApexType:
-				modules[i].(*apexBundle).properties.ApexType = flattenedApex
-				// See the comment above for why system_ext.
-				if !mctx.Config().FlattenApex() && ab.Platform() {
-					modules[i].(*apexBundle).MakeAsSystemExt()
-				}
 			}
 		}
 	} else if _, ok := mctx.Module().(*OverrideApex); ok {
 		// payload_type is forcibly overridden to "image"
 		// TODO(jiyong): is this the right decision?
-		mctx.CreateVariations(imageApexType, flattenedApexType)
+		mctx.CreateVariations(imageApexType)
 	}
 }
 
@@ -1497,9 +1473,6 @@ func (a *apexBundle) OutputFiles(tag string) (android.Paths, error) {
 var _ multitree.Exportable = (*apexBundle)(nil)
 
 func (a *apexBundle) Exportable() bool {
-	if a.properties.ApexType == flattenedApex {
-		return false
-	}
 	return true
 }
 
@@ -2143,15 +2116,10 @@ func (a *apexBundle) setPayloadFsType(ctx android.ModuleContext) {
 
 func (a *apexBundle) setApexTypeAndSuffix(ctx android.ModuleContext) {
 	// Set suffix and primaryApexType depending on the ApexType
-	buildFlattenedAsDefault := ctx.Config().FlattenApex()
 	switch a.properties.ApexType {
 	case imageApex:
-		if buildFlattenedAsDefault {
-			a.suffix = imageApexSuffix
-		} else {
-			a.suffix = ""
-			a.primaryApexType = true
-		}
+		a.suffix = ""
+		a.primaryApexType = true
 	case zipApex:
 		if proptools.String(a.properties.Payload_type) == "zip" {
 			a.suffix = ""
@@ -2159,17 +2127,10 @@ func (a *apexBundle) setApexTypeAndSuffix(ctx android.ModuleContext) {
 		} else {
 			a.suffix = zipApexSuffix
 		}
-	case flattenedApex:
-		if buildFlattenedAsDefault {
-			a.suffix = ""
-			a.primaryApexType = true
-		} else {
-			a.suffix = flattenedSuffix
-		}
 	}
 }
 
-func (a apexBundle) isCompressable() bool {
+func (a *apexBundle) isCompressable() bool {
 	return proptools.BoolDefault(a.overridableProperties.Compressible, false) && !a.testApex
 }
 
@@ -2668,32 +2629,9 @@ func (a *apexBundle) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	////////////////////////////////////////////////////////////////////////////////////////////
 	// 4) generate the build rules to create the APEX. This is done in builder.go.
 	a.buildManifest(ctx, vctx.provideNativeLibs, vctx.requireNativeLibs)
-	if a.properties.ApexType == flattenedApex {
-		a.buildFlattenedApex(ctx)
-	} else {
-		a.buildUnflattenedApex(ctx)
-	}
+	a.buildApex(ctx)
 	a.buildApexDependencyInfo(ctx)
 	a.buildLintReports(ctx)
-
-	// Append meta-files to the filesInfo list so that they are reflected in Android.mk as well.
-	if a.installable() {
-		// For flattened APEX, make sure that APEX manifest and apex_pubkey are also copied
-		// along with other ordinary files. (Note that this is done by apexer for
-		// non-flattened APEXes)
-		a.filesInfo = append(a.filesInfo, newApexFile(ctx, a.manifestPbOut, "apex_manifest.pb", ".", etc, nil))
-
-		// Place the public key as apex_pubkey. This is also done by apexer for
-		// non-flattened APEXes case.
-		// TODO(jiyong): Why do we need this CP rule?
-		copiedPubkey := android.PathForModuleOut(ctx, "apex_pubkey")
-		ctx.Build(pctx, android.BuildParams{
-			Rule:   android.Cp,
-			Input:  a.publicKeyFile,
-			Output: copiedPubkey,
-		})
-		a.filesInfo = append(a.filesInfo, newApexFile(ctx, copiedPubkey, "apex_pubkey", ".", etc, nil))
-	}
 }
 
 // apexBootclasspathFragmentFiles returns the list of apexFile structures defining the files that
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 984ca4170..b67535a18 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3206,7 +3206,7 @@ func TestAndroidMk_VendorApexRequired(t *testing.T) {
 	var builder strings.Builder
 	data.Custom(&builder, name, prefix, "", data)
 	androidMk := builder.String()
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := libc++.vendor.myapex:64 mylib.vendor.myapex:64 apex_manifest.pb.myapex apex_pubkey.myapex libc.vendor libm.vendor libdl.vendor\n")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := libc++.vendor.myapex:64 mylib.vendor.myapex:64 libc.vendor libm.vendor libdl.vendor\n")
 }
 
 func TestAndroidMkWritesCommonProperties(t *testing.T) {
@@ -4934,17 +4934,17 @@ func TestApexWithShBinary(t *testing.T) {
 
 func TestApexInVariousPartition(t *testing.T) {
 	testcases := []struct {
-		propName, parition, flattenedPartition string
+		propName, partition string
 	}{
-		{"", "system", "system_ext"},
-		{"product_specific: true", "product", "product"},
-		{"soc_specific: true", "vendor", "vendor"},
-		{"proprietary: true", "vendor", "vendor"},
-		{"vendor: true", "vendor", "vendor"},
-		{"system_ext_specific: true", "system_ext", "system_ext"},
+		{"", "system"},
+		{"product_specific: true", "product"},
+		{"soc_specific: true", "vendor"},
+		{"proprietary: true", "vendor"},
+		{"vendor: true", "vendor"},
+		{"system_ext_specific: true", "system_ext"},
 	}
 	for _, tc := range testcases {
-		t.Run(tc.propName+":"+tc.parition, func(t *testing.T) {
+		t.Run(tc.propName+":"+tc.partition, func(t *testing.T) {
 			ctx := testApex(t, `
 				apex {
 					name: "myapex",
@@ -4961,18 +4961,11 @@ func TestApexInVariousPartition(t *testing.T) {
 			`)
 
 			apex := ctx.ModuleForTests("myapex", "android_common_myapex_image").Module().(*apexBundle)
-			expected := "out/soong/target/product/test_device/" + tc.parition + "/apex"
+			expected := "out/soong/target/product/test_device/" + tc.partition + "/apex"
 			actual := apex.installDir.RelativeToTop().String()
 			if actual != expected {
 				t.Errorf("wrong install path. expected %q. actual %q", expected, actual)
 			}
-
-			flattened := ctx.ModuleForTests("myapex", "android_common_myapex_flattened").Module().(*apexBundle)
-			expected = "out/soong/target/product/test_device/" + tc.flattenedPartition + "/apex"
-			actual = flattened.installDir.RelativeToTop().String()
-			if actual != expected {
-				t.Errorf("wrong install path. expected %q. actual %q", expected, actual)
-			}
 		})
 	}
 }
@@ -6110,16 +6103,7 @@ func TestApexWithTests(t *testing.T) {
 	ensureContains(t, androidMk, "LOCAL_MODULE := mytest1.myapex\n")
 	ensureContains(t, androidMk, "LOCAL_MODULE := mytest2.myapex\n")
 	ensureContains(t, androidMk, "LOCAL_MODULE := mytest3.myapex\n")
-	ensureContains(t, androidMk, "LOCAL_MODULE := apex_manifest.pb.myapex\n")
-	ensureContains(t, androidMk, "LOCAL_MODULE := apex_pubkey.myapex\n")
 	ensureContains(t, androidMk, "LOCAL_MODULE := myapex\n")
-
-	flatBundle := ctx.ModuleForTests("myapex", "android_common_myapex_flattened").Module().(*apexBundle)
-	data = android.AndroidMkDataForTest(t, ctx, flatBundle)
-	data.Custom(&builder, name, prefix, "", data)
-	flatAndroidMk := builder.String()
-	ensureContainsOnce(t, flatAndroidMk, "LOCAL_TEST_DATA := :baz :bar/baz\n")
-	ensureContainsOnce(t, flatAndroidMk, "LOCAL_TEST_DATA := :testdata/baz\n")
 }
 
 func TestErrorsIfDepsAreNotEnabled(t *testing.T) {
@@ -7169,13 +7153,11 @@ func TestOverrideApex(t *testing.T) {
 	androidMk := builder.String()
 	ensureContains(t, androidMk, "LOCAL_MODULE := override_app.override_myapex")
 	ensureContains(t, androidMk, "LOCAL_MODULE := overrideBpf.o.override_myapex")
-	ensureContains(t, androidMk, "LOCAL_MODULE := apex_manifest.pb.override_myapex")
 	ensureContains(t, androidMk, "LOCAL_MODULE_STEM := override_myapex.apex")
 	ensureContains(t, androidMk, "LOCAL_OVERRIDES_MODULES := unknownapex myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := app.myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := bpf.myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := override_app.myapex")
-	ensureNotContains(t, androidMk, "LOCAL_MODULE := apex_manifest.pb.myapex")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE_STEM := myapex.apex")
 }
 
@@ -7758,7 +7740,7 @@ func TestCarryRequiredModuleNames(t *testing.T) {
 	var builder strings.Builder
 	data.Custom(&builder, name, prefix, "", data)
 	androidMk := builder.String()
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := mylib.myapex:64 apex_manifest.pb.myapex apex_pubkey.myapex a b\n")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := mylib.myapex:64 a b\n")
 	ensureContains(t, androidMk, "LOCAL_HOST_REQUIRED_MODULES := c d\n")
 	ensureContains(t, androidMk, "LOCAL_TARGET_REQUIRED_MODULES := e f\n")
 }
@@ -7966,7 +7948,7 @@ func TestSymlinksFromApexToSystemRequiredModuleNames(t *testing.T) {
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := prebuilt_myotherlib.myapex\n")
 	ensureNotContains(t, androidMk, "LOCAL_MODULE := myotherlib.myapex\n")
 	// `myapex` should have `myotherlib` in its required line, not `prebuilt_myotherlib`
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := mylib.myapex:64 myotherlib:64 apex_manifest.pb.myapex apex_pubkey.myapex\n")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := mylib.myapex:64 myotherlib:64\n")
 }
 
 func TestApexWithJniLibs(t *testing.T) {
@@ -9295,7 +9277,7 @@ func TestApexKeysTxt(t *testing.T) {
 
 	apexKeysText := ctx.SingletonForTests("apex_keys_text")
 	content := apexKeysText.MaybeDescription("apexkeys.txt").BuildParams.Args["content"]
-	ensureContains(t, content, `name="myapex.apex" public_key="vendor/foo/devkeys/testkey.avbpubkey" private_key="vendor/foo/devkeys/testkey.pem" container_certificate="vendor/foo/devkeys/test.x509.pem" container_private_key="vendor/foo/devkeys/test.pk8" partition="system_ext" sign_tool="sign_myapex"`)
+	ensureContains(t, content, `name="myapex.apex" public_key="vendor/foo/devkeys/testkey.avbpubkey" private_key="vendor/foo/devkeys/testkey.pem" container_certificate="vendor/foo/devkeys/test.x509.pem" container_private_key="vendor/foo/devkeys/test.pk8" partition="system" sign_tool="sign_myapex"`)
 }
 
 func TestApexKeysTxtOverrides(t *testing.T) {
@@ -9518,7 +9500,7 @@ func TestPreferredPrebuiltSharedLibDep(t *testing.T) {
 
 	// The make level dependency needs to be on otherlib - prebuilt_otherlib isn't
 	// a thing there.
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := libc++:64 mylib.myapex:64 apex_manifest.pb.myapex apex_pubkey.myapex otherlib\n")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := libc++:64 mylib.myapex:64 otherlib\n")
 }
 
 func TestExcludeDependency(t *testing.T) {
@@ -9912,7 +9894,7 @@ func TestAndroidMk_DexpreoptBuiltInstalledForApex(t *testing.T) {
 	var builder strings.Builder
 	data.Custom(&builder, apexBundle.BaseModuleName(), "TARGET_", "", data)
 	androidMk := builder.String()
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := foo.myapex apex_manifest.pb.myapex apex_pubkey.myapex foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.odex foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.vdex\n")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := foo.myapex foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.odex foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.vdex\n")
 }
 
 func TestAndroidMk_DexpreoptBuiltInstalledForApex_Prebuilt(t *testing.T) {
@@ -9988,7 +9970,7 @@ func TestAndroidMk_RequiredModules(t *testing.T) {
 	var builder strings.Builder
 	data.Custom(&builder, apexBundle.BaseModuleName(), "TARGET_", "", data)
 	androidMk := builder.String()
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := foo.myapex apex_manifest.pb.myapex apex_pubkey.myapex otherapex")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := foo.myapex otherapex")
 }
 
 func TestAndroidMk_RequiredDeps(t *testing.T) {
@@ -10012,15 +9994,7 @@ func TestAndroidMk_RequiredDeps(t *testing.T) {
 	var builder strings.Builder
 	data.Custom(&builder, bundle.BaseModuleName(), "TARGET_", "", data)
 	androidMk := builder.String()
-	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := apex_manifest.pb.myapex apex_pubkey.myapex foo\n")
-
-	flattenedBundle := ctx.ModuleForTests("myapex", "android_common_myapex_flattened").Module().(*apexBundle)
-	flattenedBundle.makeModulesToInstall = append(flattenedBundle.makeModulesToInstall, "foo")
-	flattenedData := android.AndroidMkDataForTest(t, ctx, flattenedBundle)
-	var flattenedBuilder strings.Builder
-	flattenedData.Custom(&flattenedBuilder, flattenedBundle.BaseModuleName(), "TARGET_", "", flattenedData)
-	flattenedAndroidMk := flattenedBuilder.String()
-	ensureContains(t, flattenedAndroidMk, "LOCAL_REQUIRED_MODULES := apex_manifest.pb.myapex.flattened apex_pubkey.myapex.flattened foo\n")
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES := foo\n")
 }
 
 func TestApexOutputFileProducer(t *testing.T) {
diff --git a/apex/builder.go b/apex/builder.go
index a2fe2a0d2..db66a72ce 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -382,23 +382,6 @@ func (a *apexBundle) buildFileContexts(ctx android.ModuleContext) android.Output
 			rule.Command().Text("echo").Text("/apex_manifest\\\\.pb").Text(forceLabel).Text(">>").Output(output)
 			rule.Command().Text("echo").Text("/").Text(forceLabel).Text(">>").Output(output)
 		}
-	case flattenedApex:
-		// For flattened apexes, install path should be prepended.
-		// File_contexts file should be emiited to make via LOCAL_FILE_CONTEXTS
-		// so that it can be merged into file_contexts.bin
-		apexPath := android.InstallPathToOnDevicePath(ctx, a.installDir.Join(ctx, a.Name()))
-		apexPath = strings.ReplaceAll(apexPath, ".", `\\.`)
-		// remove old file
-		rule.Command().Text("rm").FlagWithOutput("-f ", output)
-		// copy file_contexts
-		rule.Command().Text("awk").Text(`'/object_r/{printf("` + apexPath + `%s\n", $0)}'`).Input(fileContexts).Text(">").Output(output)
-		// new line
-		rule.Command().Text("echo").Text(">>").Output(output)
-		if !useFileContextsAsIs {
-			// force-label /apex_manifest.pb and /
-			rule.Command().Text("echo").Text(apexPath + "/apex_manifest\\\\.pb").Text(forceLabel).Text(">>").Output(output)
-			rule.Command().Text("echo").Text(apexPath + "/").Text(forceLabel).Text(">>").Output(output)
-		}
 	default:
 		panic(fmt.Errorf("unsupported type %v", a.properties.ApexType))
 	}
@@ -479,8 +462,8 @@ func markManifestTestOnly(ctx android.ModuleContext, androidManifestFile android
 	})
 }
 
-// buildUnflattendApex creates build rules to build an APEX using apexer.
-func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext) {
+// buildApex creates build rules to build an APEX using apexer.
+func (a *apexBundle) buildApex(ctx android.ModuleContext) {
 	apexType := a.properties.ApexType
 	suffix := apexType.suffix()
 	apexName := a.BaseModuleName()
@@ -963,49 +946,6 @@ func (a *apexBundle) buildUnflattenedApex(ctx android.ModuleContext) {
 	a.installedFilesFile = a.buildInstalledFilesFile(ctx, a.outputFile, imageDir)
 }
 
-// buildFlattenedApex creates rules for a flattened APEX. Flattened APEX actually doesn't have a
-// single output file. It is a phony target for all the files under /system/apex/<name> directory.
-// This function creates the installation rules for the files.
-func (a *apexBundle) buildFlattenedApex(ctx android.ModuleContext) {
-	bundleName := a.Name()
-	installedSymlinks := append(android.InstallPaths(nil), a.compatSymlinks...)
-	if a.installable() {
-		for _, fi := range a.filesInfo {
-			dir := filepath.Join("apex", bundleName, fi.installDir)
-			installDir := android.PathForModuleInstall(ctx, dir)
-			if a.linkToSystemLib && fi.transitiveDep && fi.availableToPlatform() {
-				pathOnDevice := filepath.Join("/", fi.partition, fi.path())
-				installedSymlinks = append(installedSymlinks,
-					ctx.InstallAbsoluteSymlink(installDir, fi.stem(), pathOnDevice))
-			} else {
-				if fi.class == appSet {
-					as := fi.module.(*java.AndroidAppSet)
-					ctx.InstallFileWithExtraFilesZip(installDir, as.BaseModuleName()+".apk",
-						as.OutputFile(), as.PackedAdditionalOutputs())
-				} else {
-					target := ctx.InstallFile(installDir, fi.stem(), fi.builtFile)
-					for _, sym := range fi.symlinks {
-						installedSymlinks = append(installedSymlinks,
-							ctx.InstallSymlink(installDir, sym, target))
-					}
-				}
-			}
-		}
-
-		// Create install rules for the files added in GenerateAndroidBuildActions after
-		// buildFlattenedApex is called.  Add the links to system libs (if any) as dependencies
-		// of the apex_manifest.pb file since it is always present.
-		dir := filepath.Join("apex", bundleName)
-		installDir := android.PathForModuleInstall(ctx, dir)
-		ctx.InstallFile(installDir, "apex_manifest.pb", a.manifestPbOut, installedSymlinks.Paths()...)
-		ctx.InstallFile(installDir, "apex_pubkey", a.publicKeyFile)
-	}
-
-	a.fileContexts = a.buildFileContexts(ctx)
-
-	a.outputFile = android.PathForModuleInstall(ctx, "apex", bundleName)
-}
-
 // getCertificateAndPrivateKey retrieves the cert and the private key that will be used to sign
 // the zip container of this APEX. See the description of the 'certificate' property for how
 // the cert and the private key are found.
diff --git a/apex/prebuilt.go b/apex/prebuilt.go
index 0d83830f1..3509e6cbe 100644
--- a/apex/prebuilt.go
+++ b/apex/prebuilt.go
@@ -133,9 +133,7 @@ func (p *prebuiltCommon) isForceDisabled() bool {
 }
 
 func (p *prebuiltCommon) checkForceDisable(ctx android.ModuleContext) bool {
-	// If the device is configured to use flattened APEX, force disable the prebuilt because
-	// the prebuilt is a non-flattened one.
-	forceDisable := ctx.Config().FlattenApex()
+	forceDisable := false
 
 	// Force disable the prebuilts when we are doing unbundled build. We do unbundled build
 	// to build the prebuilts themselves.