diff --git a/android/variable.go b/android/variable.go
index 142fab9..f82c9ca 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -577,6 +577,14 @@
 	BoardAvbRollbackIndexLocation string `json:",omitempty"`
 }
 
+type ChainedAvbPartitionProps struct {
+	Partitions            []string `json:",omitempty"`
+	Key                   string   `json:",omitempty"`
+	Algorithm             string   `json:",omitempty"`
+	RollbackIndex         string   `json:",omitempty"`
+	RollbackIndexLocation string   `json:",omitempty"`
+}
+
 type PartitionVariables struct {
 	ProductDirectory            string `json:",omitempty"`
 	PartitionQualifiedVariables map[string]PartitionQualifiedVariablesType
@@ -601,7 +609,12 @@
 	ProductUseDynamicPartitionSize bool   `json:",omitempty"`
 	CopyImagesForTargetFilesZip    bool   `json:",omitempty"`
 
-	BoardAvbEnable bool `json:",omitempty"`
+	BoardAvbEnable          bool                                `json:",omitempty"`
+	BoardAvbAlgorithm       string                              `json:",omitempty"`
+	BoardAvbKeyPath         string                              `json:",omitempty"`
+	BoardAvbRollbackIndex   string                              `json:",omitempty"`
+	BuildingVbmetaImage     bool                                `json:",omitempty"`
+	ChainedVbmetaPartitions map[string]ChainedAvbPartitionProps `json:",omitempty"`
 
 	ProductPackages         []string `json:",omitempty"`
 	ProductPackagesDebug    []string `json:",omitempty"`
diff --git a/filesystem/android_device.go b/filesystem/android_device.go
index 9071272..2645dc4 100644
--- a/filesystem/android_device.go
+++ b/filesystem/android_device.go
@@ -34,6 +34,8 @@
 	Vendor_partition_name *string
 	// Name of the Odm partition filesystem module
 	Odm_partition_name *string
+	// The vbmeta partition and its "chained" partitions
+	Vbmeta_partitions []string
 }
 
 type androidDevice struct {
@@ -46,7 +48,6 @@
 	module := &androidDevice{}
 	module.AddProperties(&module.partitionProps)
 	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
-
 	return module
 }
 
@@ -69,6 +70,9 @@
 	addDependencyIfDefined(a.partitionProps.Product_partition_name)
 	addDependencyIfDefined(a.partitionProps.Vendor_partition_name)
 	addDependencyIfDefined(a.partitionProps.Odm_partition_name)
+	for _, vbmetaPartition := range a.partitionProps.Vbmeta_partitions {
+		ctx.AddDependency(ctx.Module(), filesystemDepTag, vbmetaPartition)
+	}
 }
 
 func (a *androidDevice) GenerateAndroidBuildActions(ctx android.ModuleContext) {
diff --git a/filesystem/vbmeta.go b/filesystem/vbmeta.go
index 0bae479..6a3fc1f 100644
--- a/filesystem/vbmeta.go
+++ b/filesystem/vbmeta.go
@@ -25,19 +25,19 @@
 )
 
 func init() {
-	android.RegisterModuleType("vbmeta", vbmetaFactory)
+	android.RegisterModuleType("vbmeta", VbmetaFactory)
 }
 
 type vbmeta struct {
 	android.ModuleBase
 
-	properties vbmetaProperties
+	properties VbmetaProperties
 
 	output     android.OutputPath
 	installDir android.InstallPath
 }
 
-type vbmetaProperties struct {
+type VbmetaProperties struct {
 	// Name of the partition stored in vbmeta desc. Defaults to the name of this module.
 	Partition_name *string
 
@@ -50,9 +50,8 @@
 	// Algorithm that avbtool will use to sign this vbmeta image. Default is SHA256_RSA4096.
 	Algorithm *string
 
-	// File whose content will provide the rollback index. If unspecified, the rollback index
-	// is from PLATFORM_SECURITY_PATCH
-	Rollback_index_file *string `android:"path"`
+	// The rollback index. If unspecified, the rollback index is from PLATFORM_SECURITY_PATCH
+	Rollback_index *int64
 
 	// Rollback index location of this vbmeta image. Must be 0, 1, 2, etc. Default is 0.
 	Rollback_index_location *int64
@@ -62,7 +61,7 @@
 	Partitions proptools.Configurable[[]string]
 
 	// List of chained partitions that this vbmeta deletages the verification.
-	Chained_partitions []chainedPartitionProperties
+	Chained_partitions []ChainedPartitionProperties
 
 	// List of key-value pair of avb properties
 	Avb_properties []avbProperty
@@ -76,7 +75,7 @@
 	Value *string
 }
 
-type chainedPartitionProperties struct {
+type ChainedPartitionProperties struct {
 	// Name of the chained partition
 	Name *string
 
@@ -95,7 +94,7 @@
 }
 
 // vbmeta is the partition image that has the verification information for other partitions.
-func vbmetaFactory() android.Module {
+func VbmetaFactory() android.Module {
 	module := &vbmeta{}
 	module.AddProperties(&module.properties)
 	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibCommon)
@@ -217,15 +216,12 @@
 
 // Returns the embedded shell command that prints the rollback index
 func (v *vbmeta) rollbackIndexCommand(ctx android.ModuleContext) string {
-	var cmd string
-	if v.properties.Rollback_index_file != nil {
-		f := android.PathForModuleSrc(ctx, proptools.String(v.properties.Rollback_index_file))
-		cmd = "cat " + f.String()
+	if v.properties.Rollback_index != nil {
+		return fmt.Sprintf("%d", *v.properties.Rollback_index)
 	} else {
-		cmd = "date -d 'TZ=\"GMT\" " + ctx.Config().PlatformSecurityPatch() + "' +%s"
+		// Take the first line and remove the newline char
+		return "$(date -d 'TZ=\"GMT\" " + ctx.Config().PlatformSecurityPatch() + "' +%s | head -1 | tr -d '\n'" + ")"
 	}
-	// Take the first line and remove the newline char
-	return "$(" + cmd + " | head -1 | tr -d '\n'" + ")"
 }
 
 // Extract public keys from chained_partitions.private_key. The keys are indexed with the partition
diff --git a/fsgen/Android.bp b/fsgen/Android.bp
index 690ad28..8cd7518 100644
--- a/fsgen/Android.bp
+++ b/fsgen/Android.bp
@@ -16,6 +16,7 @@
         "filesystem_creator.go",
         "fsgen_mutators.go",
         "prebuilt_etc_modules_gen.go",
+        "vbmeta_partitions.go",
     ],
     testSrcs: [
         "filesystem_creator_test.go",
diff --git a/fsgen/filesystem_creator.go b/fsgen/filesystem_creator.go
index bdffabf..b580ea9 100644
--- a/fsgen/filesystem_creator.go
+++ b/fsgen/filesystem_creator.go
@@ -44,6 +44,9 @@
 type filesystemCreatorProps struct {
 	Generated_partition_types   []string `blueprint:"mutated"`
 	Unsupported_partition_types []string `blueprint:"mutated"`
+
+	Vbmeta_module_names    []string `blueprint:"mutated"`
+	Vbmeta_partition_names []string `blueprint:"mutated"`
 }
 
 type filesystemCreator struct {
@@ -67,16 +70,24 @@
 }
 
 func (f *filesystemCreator) createInternalModules(ctx android.LoadHookContext) {
-	soongGeneratedPartitions := &ctx.Config().Get(fsGenStateOnceKey).(*FsGenState).soongGeneratedPartitions
-	for _, partitionType := range *soongGeneratedPartitions {
+	soongGeneratedPartitions := generatedPartitions(ctx)
+	finalSoongGeneratedPartitions := make([]string, 0, len(soongGeneratedPartitions))
+	for _, partitionType := range soongGeneratedPartitions {
 		if f.createPartition(ctx, partitionType) {
 			f.properties.Generated_partition_types = append(f.properties.Generated_partition_types, partitionType)
+			finalSoongGeneratedPartitions = append(finalSoongGeneratedPartitions, partitionType)
 		} else {
 			f.properties.Unsupported_partition_types = append(f.properties.Unsupported_partition_types, partitionType)
-			_, *soongGeneratedPartitions = android.RemoveFromList(partitionType, *soongGeneratedPartitions)
 		}
 	}
-	f.createDeviceModule(ctx)
+
+	for _, x := range createVbmetaPartitions(ctx, finalSoongGeneratedPartitions) {
+		f.properties.Vbmeta_module_names = append(f.properties.Vbmeta_module_names, x.moduleName)
+		f.properties.Vbmeta_partition_names = append(f.properties.Vbmeta_partition_names, x.partitionName)
+	}
+
+	ctx.Config().Get(fsGenStateOnceKey).(*FsGenState).soongGeneratedPartitions = finalSoongGeneratedPartitions
+	f.createDeviceModule(ctx, finalSoongGeneratedPartitions, f.properties.Vbmeta_module_names)
 }
 
 func generatedModuleName(cfg android.Config, suffix string) string {
@@ -91,7 +102,11 @@
 	return generatedModuleName(cfg, fmt.Sprintf("%s_image", partitionType))
 }
 
-func (f *filesystemCreator) createDeviceModule(ctx android.LoadHookContext) {
+func (f *filesystemCreator) createDeviceModule(
+	ctx android.LoadHookContext,
+	generatedPartitionTypes []string,
+	vbmetaPartitions []string,
+) {
 	baseProps := &struct {
 		Name *string
 	}{
@@ -100,21 +115,22 @@
 
 	// Currently, only the system and system_ext partition module is created.
 	partitionProps := &filesystem.PartitionNameProperties{}
-	if android.InList("system", f.properties.Generated_partition_types) {
+	if android.InList("system", generatedPartitionTypes) {
 		partitionProps.System_partition_name = proptools.StringPtr(generatedModuleNameForPartition(ctx.Config(), "system"))
 	}
-	if android.InList("system_ext", f.properties.Generated_partition_types) {
+	if android.InList("system_ext", generatedPartitionTypes) {
 		partitionProps.System_ext_partition_name = proptools.StringPtr(generatedModuleNameForPartition(ctx.Config(), "system_ext"))
 	}
-	if android.InList("vendor", f.properties.Generated_partition_types) {
+	if android.InList("vendor", generatedPartitionTypes) {
 		partitionProps.Vendor_partition_name = proptools.StringPtr(generatedModuleNameForPartition(ctx.Config(), "vendor"))
 	}
-	if android.InList("product", f.properties.Generated_partition_types) {
+	if android.InList("product", generatedPartitionTypes) {
 		partitionProps.Product_partition_name = proptools.StringPtr(generatedModuleNameForPartition(ctx.Config(), "product"))
 	}
-	if android.InList("odm", f.properties.Generated_partition_types) {
+	if android.InList("odm", generatedPartitionTypes) {
 		partitionProps.Odm_partition_name = proptools.StringPtr(generatedModuleNameForPartition(ctx.Config(), "odm"))
 	}
+	partitionProps.Vbmeta_partitions = vbmetaPartitions
 
 	ctx.CreateModule(filesystem.AndroidDeviceFactory, baseProps, partitionProps)
 }
@@ -334,12 +350,15 @@
 type filesystemBaseProperty struct {
 	Name             *string
 	Compile_multilib *string
+	Visibility       []string
 }
 
 func generateBaseProps(namePtr *string) *filesystemBaseProperty {
 	return &filesystemBaseProperty{
 		Name:             namePtr,
 		Compile_multilib: proptools.StringPtr("both"),
+		// The vbmeta modules are currently in the root directory and depend on the partitions
+		Visibility: []string{"//.", "//build/soong:__subpackages__"},
 	}
 }
 
@@ -435,16 +454,42 @@
 	return file
 }
 
+func createVbmetaDiff(ctx android.ModuleContext, vbmetaModuleName string, vbmetaPartitionName string) android.Path {
+	vbmetaModule := ctx.GetDirectDepWithTag(vbmetaModuleName, generatedVbmetaPartitionDepTag)
+	outputFilesProvider, ok := android.OtherModuleProvider(ctx, vbmetaModule, android.OutputFilesProvider)
+	if !ok {
+		ctx.ModuleErrorf("Expected module %s to provide OutputFiles", vbmetaModule)
+	}
+	if len(outputFilesProvider.DefaultOutputFiles) != 1 {
+		ctx.ModuleErrorf("Expected 1 output file from module %s", vbmetaModule)
+	}
+	soongVbMetaFile := outputFilesProvider.DefaultOutputFiles[0]
+	makeVbmetaFile := android.PathForArbitraryOutput(ctx, fmt.Sprintf("target/product/%s/%s.img", ctx.Config().DeviceName(), vbmetaPartitionName))
+
+	diffTestResultFile := android.PathForModuleOut(ctx, fmt.Sprintf("diff_test_%s.txt", vbmetaModuleName))
+	builder := android.NewRuleBuilder(pctx, ctx)
+	builder.Command().Text("diff").
+		Input(soongVbMetaFile).
+		Input(makeVbmetaFile)
+	builder.Command().Text("touch").Output(diffTestResultFile)
+	builder.Build(vbmetaModuleName+" diff test", vbmetaModuleName+" diff test")
+	return diffTestResultFile
+}
+
 type systemImageDepTagType struct {
 	blueprint.BaseDependencyTag
 }
 
 var generatedFilesystemDepTag systemImageDepTagType
+var generatedVbmetaPartitionDepTag systemImageDepTagType
 
 func (f *filesystemCreator) DepsMutator(ctx android.BottomUpMutatorContext) {
 	for _, partitionType := range f.properties.Generated_partition_types {
 		ctx.AddDependency(ctx.Module(), generatedFilesystemDepTag, generatedModuleNameForPartition(ctx.Config(), partitionType))
 	}
+	for _, vbmetaModule := range f.properties.Vbmeta_module_names {
+		ctx.AddDependency(ctx.Module(), generatedVbmetaPartitionDepTag, vbmetaModule)
+	}
 }
 
 func (f *filesystemCreator) GenerateAndroidBuildActions(ctx android.ModuleContext) {
@@ -474,6 +519,11 @@
 		diffTestFiles = append(diffTestFiles, diffTestFile)
 		ctx.Phony(fmt.Sprintf("soong_generated_%s_filesystem_test", partitionType), diffTestFile)
 	}
+	for i, vbmetaModule := range f.properties.Vbmeta_module_names {
+		diffTestFile := createVbmetaDiff(ctx, vbmetaModule, f.properties.Vbmeta_partition_names[i])
+		diffTestFiles = append(diffTestFiles, diffTestFile)
+		ctx.Phony(fmt.Sprintf("soong_generated_%s_filesystem_test", f.properties.Vbmeta_partition_names[i]), diffTestFile)
+	}
 	ctx.Phony("soong_generated_filesystem_tests", diffTestFiles...)
 }
 
diff --git a/fsgen/fsgen_mutators.go b/fsgen/fsgen_mutators.go
index f3aec00..92ea128 100644
--- a/fsgen/fsgen_mutators.go
+++ b/fsgen/fsgen_mutators.go
@@ -145,7 +145,6 @@
 				},
 				"system_dlkm": {},
 			},
-			soongGeneratedPartitions:  generatedPartitions(ctx),
 			fsDepsMutex:               sync.Mutex{},
 			moduleToInstallationProps: map[string]installationProperties{},
 		}
diff --git a/fsgen/vbmeta_partitions.go b/fsgen/vbmeta_partitions.go
new file mode 100644
index 0000000..f5b5f1c
--- /dev/null
+++ b/fsgen/vbmeta_partitions.go
@@ -0,0 +1,174 @@
+// Copyright (C) 2024 The Android Open Source Project
+//
+// 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.
+
+package fsgen
+
+import (
+	"android/soong/android"
+	"android/soong/filesystem"
+	"slices"
+	"strconv"
+
+	"github.com/google/blueprint/proptools"
+)
+
+type vbmetaModuleInfo struct {
+	// The name of the generated vbmeta module
+	moduleName string
+	// The name of the module that avb understands. This is the name passed to --chain_partition,
+	// and also the basename of the output file. (the output file is called partitionName + ".img")
+	partitionName string
+}
+
+// Creates the vbmeta partition and the chained vbmeta partitions. Returns the list of module names
+// that the function created. May return nil if the product isn't using avb.
+//
+// AVB is Android Verified Boot: https://source.android.com/docs/security/features/verifiedboot
+// It works by signing all the partitions, but then also including an extra metadata paritition
+// called vbmeta that depends on all the other signed partitions. This creates a requirement
+// that you update all those partitions and the vbmeta partition together, so in order to relax
+// that requirement products can set up "chained" vbmeta partitions, where a chained partition
+// like vbmeta_system might contain the avb metadata for just a few products. In cuttlefish
+// vbmeta_system contains metadata about product, system, and system_ext. Using chained partitions,
+// that group of partitions can be updated independently from the other signed partitions.
+func createVbmetaPartitions(ctx android.LoadHookContext, generatedPartitionTypes []string) []vbmetaModuleInfo {
+	partitionVars := ctx.Config().ProductVariables().PartitionVarsForSoongMigrationOnlyDoNotUse
+	// Some products seem to have BuildingVbmetaImage as true even when BoardAvbEnable is false
+	if !partitionVars.BuildingVbmetaImage || !partitionVars.BoardAvbEnable {
+		return nil
+	}
+
+	var result []vbmetaModuleInfo
+
+	var chainedPartitions []filesystem.ChainedPartitionProperties
+	var partitionTypesHandledByChainedPartitions []string
+	for chainedName, props := range partitionVars.ChainedVbmetaPartitions {
+		chainedName = "vbmeta_" + chainedName
+		if len(props.Partitions) == 0 {
+			continue
+		}
+		if len(props.Key) == 0 {
+			ctx.ModuleErrorf("No key found for chained avb partition %s", chainedName)
+			continue
+		}
+		if len(props.Algorithm) == 0 {
+			ctx.ModuleErrorf("No algorithm found for chained avb partition %s", chainedName)
+			continue
+		}
+		if len(props.RollbackIndex) == 0 {
+			ctx.ModuleErrorf("No rollback index found for chained avb partition %s", chainedName)
+			continue
+		}
+		ril, err := strconv.ParseInt(props.RollbackIndexLocation, 10, 32)
+		if err != nil {
+			ctx.ModuleErrorf("Rollback index location must be an int, got %s", props.RollbackIndexLocation)
+			continue
+		}
+		// The default is to use the PlatformSecurityPatch, and a lot of product config files
+		// just set it to the platform security patch, so detect that and don't set the property
+		// in soong.
+		var rollbackIndex *int64
+		if props.RollbackIndex != ctx.Config().PlatformSecurityPatch() {
+			i, err := strconv.ParseInt(props.RollbackIndex, 10, 32)
+			if err != nil {
+				ctx.ModuleErrorf("Rollback index must be an int, got %s", props.RollbackIndex)
+				continue
+			}
+			rollbackIndex = &i
+		}
+
+		var partitionModules []string
+		for _, partition := range props.Partitions {
+			partitionTypesHandledByChainedPartitions = append(partitionTypesHandledByChainedPartitions, partition)
+			if !slices.Contains(generatedPartitionTypes, partition) {
+				// The partition is probably unsupported.
+				continue
+			}
+			partitionModules = append(partitionModules, generatedModuleNameForPartition(ctx.Config(), partition))
+		}
+
+		name := generatedModuleName(ctx.Config(), chainedName)
+		ctx.CreateModuleInDirectory(
+			filesystem.VbmetaFactory,
+			".", // Create in the root directory for now so its easy to get the key
+			&filesystem.VbmetaProperties{
+				Partition_name:          proptools.StringPtr(chainedName),
+				Stem:                    proptools.StringPtr(chainedName + ".img"),
+				Private_key:             proptools.StringPtr(props.Key),
+				Algorithm:               &props.Algorithm,
+				Rollback_index:          rollbackIndex,
+				Rollback_index_location: &ril,
+				Partitions:              proptools.NewSimpleConfigurable(partitionModules),
+			}, &struct {
+				Name *string
+			}{
+				Name: &name,
+			},
+		).HideFromMake()
+
+		chainedPartitions = append(chainedPartitions, filesystem.ChainedPartitionProperties{
+			Name:                    &chainedName,
+			Rollback_index_location: &ril,
+			Private_key:             &props.Key,
+		})
+
+		result = append(result, vbmetaModuleInfo{
+			moduleName:    name,
+			partitionName: chainedName,
+		})
+	}
+
+	vbmetaModuleName := generatedModuleName(ctx.Config(), "vbmeta")
+
+	var algorithm *string
+	if len(partitionVars.BoardAvbAlgorithm) > 0 {
+		algorithm = proptools.StringPtr(partitionVars.BoardAvbAlgorithm)
+	}
+	ril, err := strconv.ParseInt(partitionVars.BoardAvbRollbackIndex, 10, 32)
+	if err != nil {
+		ctx.ModuleErrorf("Rollback index location must be an int, got %s", partitionVars.BoardAvbRollbackIndex)
+	}
+
+	var partitionModules []string
+	for _, partitionType := range generatedPartitionTypes {
+		if slices.Contains(partitionTypesHandledByChainedPartitions, partitionType) {
+			// Already handled by a chained vbmeta partition
+			continue
+		}
+		partitionModules = append(partitionModules, generatedModuleNameForPartition(ctx.Config(), partitionType))
+	}
+
+	ctx.CreateModuleInDirectory(
+		filesystem.VbmetaFactory,
+		".", // Create in the root directory for now so its easy to get the key
+		&filesystem.VbmetaProperties{
+			Stem:                    proptools.StringPtr("vbmeta.img"),
+			Algorithm:               algorithm,
+			Private_key:             proptools.StringPtr(partitionVars.BoardAvbKeyPath),
+			Rollback_index_location: &ril,
+			Chained_partitions:      chainedPartitions,
+			Partitions:              proptools.NewSimpleConfigurable(partitionModules),
+		}, &struct {
+			Name *string
+		}{
+			Name: &vbmetaModuleName,
+		},
+	).HideFromMake()
+
+	result = append(result, vbmetaModuleInfo{
+		moduleName:    vbmetaModuleName,
+		partitionName: "vbmeta",
+	})
+	return result
+}