filesystem/vbmeta.go - android_build_soong - Gitiles

 // Copyright (C) 2021 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 filesystem

 import (
 	"fmt"
 	"strconv"

 	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"

 	"android/soong/android"
 )

 func init() {
 	android.RegisterModuleType("vbmeta", VbmetaFactory)
 	pctx.HostBinToolVariable("avbtool", "avbtool")
 }

 var (
 	extractPublicKeyRule = pctx.AndroidStaticRule("avb_extract_public_key",
 		blueprint.RuleParams{
 			Command: `${avbtool} extract_public_key --key $in --output $out`,
 			CommandDeps: []string{
 				"${avbtool}",
 			},
 		})
 )

 type vbmeta struct {
 	android.ModuleBase

 	properties VbmetaProperties

 	output     android.Path
 	installDir android.InstallPath
 }

 type VbmetaProperties struct {
 	// Name of the partition stored in vbmeta desc. Defaults to the name of this module.
 	Partition_name *string

 	// Set the name of the output. Defaults to <module_name>.img.
 	Stem *string

 	// Path to the private key that avbtool will use to sign this vbmeta image.
 	Private_key *string `android:"path"`

 	// Algorithm that avbtool will use to sign this vbmeta image. Default is SHA256_RSA4096.
 	Algorithm *string

 	// 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

 	// List of filesystem modules that this vbmeta has descriptors for. The filesystem modules
 	// have to be signed (use_avb: true).
 	Partitions proptools.Configurable[[]string]

 	// Metadata about the chained partitions that this vbmeta delegates the verification.
 	// This is an alternative to chained_partitions, using chained_partitions instead is simpler
 	// in most cases. However, this property allows building this vbmeta partition without
 	// its chained partitions existing in this build.
 	Chained_partition_metadata []ChainedPartitionProperties

 	// List of chained partitions that this vbmeta delegates the verification. They are the
 	// names of other vbmeta modules.
 	Chained_partitions []string

 	// List of key-value pair of avb properties
 	Avb_properties []avbProperty
 }

 type avbProperty struct {
 	// Key of given avb property
 	Key *string

 	// Value of given avb property
 	Value *string
 }

 type ChainedPartitionProperties struct {
 	// Name of the chained partition
 	Name *string

 	// Rollback index location of the chained partition. Must be 0, 1, 2, etc. Default is the
 	// index of this partition in the list + 1.
 	Rollback_index_location *int64

 	// Path to the public key that the chained partition is signed with. If this is specified,
 	// private_key is ignored.
 	Public_key *string `android:"path"`

 	// Path to the private key that the chained partition is signed with. If this is specified,
 	// and public_key is not specified, a public key is extracted from this private key and
 	// the extracted public key is embedded in the vbmeta image.
 	Private_key *string `android:"path"`
 }

 type vbmetaPartitionInfo struct {
 	// Name of the partition
 	Name string

 	// Rollback index location, non-negative int
 	RollbackIndexLocation int

 	// The path to the public key of the private key used to sign this partition. Derived from
 	// the private key.
 	PublicKey android.Path
 }

 var vbmetaPartitionProvider = blueprint.NewProvider[vbmetaPartitionInfo]()

 // vbmeta is the partition image that has the verification information for other partitions.
 func VbmetaFactory() android.Module {
 	module := &vbmeta{}
 	module.AddProperties(&module.properties)
 	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibCommon)
 	return module
 }

 type vbmetaDep struct {
 	blueprint.BaseDependencyTag
 }

 type chainedPartitionDep struct {
 	blueprint.BaseDependencyTag
 }

 var vbmetaPartitionDep = vbmetaDep{}
 var vbmetaChainedPartitionDep = chainedPartitionDep{}

 func (v *vbmeta) DepsMutator(ctx android.BottomUpMutatorContext) {
 	ctx.AddDependency(ctx.Module(), vbmetaPartitionDep, v.properties.Partitions.GetOrDefault(ctx, nil)...)
 	ctx.AddDependency(ctx.Module(), vbmetaChainedPartitionDep, v.properties.Chained_partitions...)
 }

 func (v *vbmeta) installFileName() string {
 	return proptools.StringDefault(v.properties.Stem, v.BaseModuleName()+".img")
 }

 func (v *vbmeta) partitionName() string {
 	return proptools.StringDefault(v.properties.Partition_name, v.BaseModuleName())
 }

 // See external/avb/libavb/avb_slot_verify.c#VBMETA_MAX_SIZE
 const vbmetaMaxSize = 64 * 1024

 func (v *vbmeta) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	builder := android.NewRuleBuilder(pctx, ctx)
 	cmd := builder.Command().BuiltTool("avbtool").Text("make_vbmeta_image")

 	key := android.PathForModuleSrc(ctx, proptools.String(v.properties.Private_key))
 	cmd.FlagWithInput("--key ", key)

 	algorithm := proptools.StringDefault(v.properties.Algorithm, "SHA256_RSA4096")
 	cmd.FlagWithArg("--algorithm ", algorithm)

 	cmd.FlagWithArg("--rollback_index ", v.rollbackIndexCommand(ctx))
 	ril := proptools.IntDefault(v.properties.Rollback_index_location, 0)
 	if ril < 0 {
 		ctx.PropertyErrorf("rollback_index_location", "must be 0, 1, 2, ...")
 		return
 	}
 	cmd.FlagWithArg("--rollback_index_location ", strconv.Itoa(ril))

 	for _, avb_prop := range v.properties.Avb_properties {
 		key := proptools.String(avb_prop.Key)
 		if key == "" {
 			ctx.PropertyErrorf("avb_properties", "key must be specified")
 			continue
 		}
 		value := proptools.String(avb_prop.Value)
 		if value == "" {
 			ctx.PropertyErrorf("avb_properties", "value must be specified")
 			continue
 		}
 		cmd.FlagWithArg("--prop ", key+":"+value)
 	}

 	for _, p := range ctx.GetDirectDepsWithTag(vbmetaPartitionDep) {
 		f, ok := p.(Filesystem)
 		if !ok {
 			ctx.PropertyErrorf("partitions", "%q(type: %s) is not supported",
 				p.Name(), ctx.OtherModuleType(p))
 			continue
 		}
 		signedImage := f.SignedOutputPath()
 		if signedImage == nil {
 			ctx.PropertyErrorf("partitions", "%q(type: %s) is not signed. Use `use_avb: true`",
 				p.Name(), ctx.OtherModuleType(p))
 			continue
 		}
 		cmd.FlagWithInput("--include_descriptors_from_image ", signedImage)
 	}

 	seenRils := make(map[int]bool)
 	for _, cp := range ctx.GetDirectDepsWithTag(vbmetaChainedPartitionDep) {
 		info, ok := android.OtherModuleProvider(ctx, cp, vbmetaPartitionProvider)
 		if !ok {
 			ctx.PropertyErrorf("chained_partitions", "Expected all modules in chained_partitions to provide vbmetaPartitionProvider, but %s did not", cp.Name())
 			continue
 		}
 		if info.Name == "" {
 			ctx.PropertyErrorf("chained_partitions", "name must be specified")
 			continue
 		}

 		ril := info.RollbackIndexLocation
 		if ril < 0 {
 			ctx.PropertyErrorf("chained_partitions", "rollback index location must be 0, 1, 2, ...")
 			continue
 		} else if seenRils[ril] {
 			ctx.PropertyErrorf("chained_partitions", "Multiple chained partitions with the same rollback index location %d", ril)
 			continue
 		}
 		seenRils[ril] = true

 		publicKey := info.PublicKey
 		cmd.FlagWithArg("--chain_partition ", fmt.Sprintf("%s:%d:%s", info.Name, ril, publicKey.String()))
 		cmd.Implicit(publicKey)
 	}
 	for _, cpm := range v.properties.Chained_partition_metadata {
 		name := proptools.String(cpm.Name)
 		if name == "" {
 			ctx.PropertyErrorf("chained_partitions", "name must be specified")
 			continue
 		}

 		ril := proptools.IntDefault(cpm.Rollback_index_location, -1)
 		if ril < 0 {
 			ctx.PropertyErrorf("chained_partition_metadata", "rollback index location must be 0, 1, 2, ...")
 			continue
 		} else if seenRils[ril] {
 			ctx.PropertyErrorf("chained_partition_metadata", "Multiple chained partitions with the same rollback index location %d", ril)
 			continue
 		}
 		seenRils[ril] = true

 		var publicKey android.Path
 		if cpm.Public_key != nil {
 			publicKey = android.PathForModuleSrc(ctx, *cpm.Public_key)
 		} else if cpm.Private_key != nil {
 			privateKey := android.PathForModuleSrc(ctx, *cpm.Private_key)
 			extractedPublicKey := android.PathForModuleOut(ctx, "chained_metadata", name+".avbpubkey")
 			ctx.Build(pctx, android.BuildParams{
 				Rule:   extractPublicKeyRule,
 				Input:  privateKey,
 				Output: extractedPublicKey,
 			})
 			publicKey = extractedPublicKey
 		} else {
 			ctx.PropertyErrorf("public_key", "Either public_key or private_key must be specified")
 			continue
 		}

 		cmd.FlagWithArg("--chain_partition ", fmt.Sprintf("%s:%d:%s", name, ril, publicKey.String()))
 		cmd.Implicit(publicKey)
 	}

 	output := android.PathForModuleOut(ctx, v.installFileName())
 	cmd.FlagWithOutput("--output ", output)

 	// libavb expects to be able to read the maximum vbmeta size, so we must provide a partition
 	// which matches this or the read will fail.
 	builder.Command().Text("truncate").
 		FlagWithArg("-s ", strconv.Itoa(vbmetaMaxSize)).
 		Output(output)

 	builder.Build("vbmeta", fmt.Sprintf("vbmeta %s", ctx.ModuleName()))

 	v.installDir = android.PathForModuleInstall(ctx, "etc")
 	ctx.InstallFile(v.installDir, v.installFileName(), output)

 	extractedPublicKey := android.PathForModuleOut(ctx, v.partitionName()+".avbpubkey")
 	ctx.Build(pctx, android.BuildParams{
 		Rule:   extractPublicKeyRule,
 		Input:  key,
 		Output: extractedPublicKey,
 	})

 	android.SetProvider(ctx, vbmetaPartitionProvider, vbmetaPartitionInfo{
 		Name:                  v.partitionName(),
 		RollbackIndexLocation: ril,
 		PublicKey:             extractedPublicKey,
 	})

 	ctx.SetOutputFiles([]android.Path{output}, "")
 	v.output = output
 }

 // Returns the embedded shell command that prints the rollback index
 func (v *vbmeta) rollbackIndexCommand(ctx android.ModuleContext) string {
 	if v.properties.Rollback_index != nil {
 		return fmt.Sprintf("%d", *v.properties.Rollback_index)
 	} else {
 		// Take the first line and remove the newline char
 		return "$(date -d 'TZ=\"GMT\" " + ctx.Config().PlatformSecurityPatch() + "' +%s | head -1 | tr -d '\n'" + ")"
 	}
 }

 var _ android.AndroidMkProviderInfoProducer = (*vbmeta)(nil)

 func (v *vbmeta) PrepareAndroidMKProviderInfo(config android.Config) *android.AndroidMkProviderInfo {
 	providerData := android.AndroidMkProviderInfo{
 		PrimaryInfo: android.AndroidMkInfo{
 			Class:      "ETC",
 			OutputFile: android.OptionalPathForPath(v.output),
 			EntryMap:   make(map[string][]string),
 		},
 	}
 	providerData.PrimaryInfo.SetString("LOCAL_MODULE_PATH", v.installDir.String())
 	providerData.PrimaryInfo.SetString("LOCAL_INSTALLED_MODULE_STEM", v.installFileName())
 	return &providerData
 }

 var _ Filesystem = (*vbmeta)(nil)

 func (v *vbmeta) OutputPath() android.Path {
 	return v.output
 }

 func (v *vbmeta) SignedOutputPath() android.Path {
 	return v.OutputPath() // vbmeta is always signed
 }
	// Copyright (C) 2021 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 filesystem

	import (
	"fmt"
	"strconv"

	"github.com/google/blueprint"
	"github.com/google/blueprint/proptools"

	"android/soong/android"
	)

	func init() {
	android.RegisterModuleType("vbmeta", VbmetaFactory)
	pctx.HostBinToolVariable("avbtool", "avbtool")
	}

	var (
	extractPublicKeyRule = pctx.AndroidStaticRule("avb_extract_public_key",
	blueprint.RuleParams{
	Command: `${avbtool} extract_public_key --key $in --output $out`,
	CommandDeps: []string{
	"${avbtool}",
	},
	})
	)

	type vbmeta struct {
	android.ModuleBase

	properties VbmetaProperties

	output android.Path
	installDir android.InstallPath
	}

	type VbmetaProperties struct {
	// Name of the partition stored in vbmeta desc. Defaults to the name of this module.
	Partition_name *string

	// Set the name of the output. Defaults to <module_name>.img.
	Stem *string

	// Path to the private key that avbtool will use to sign this vbmeta image.
	Private_key *string `android:"path"`

	// Algorithm that avbtool will use to sign this vbmeta image. Default is SHA256_RSA4096.
	Algorithm *string

	// 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

	// List of filesystem modules that this vbmeta has descriptors for. The filesystem modules
	// have to be signed (use_avb: true).
	Partitions proptools.Configurable[[]string]

	// Metadata about the chained partitions that this vbmeta delegates the verification.
	// This is an alternative to chained_partitions, using chained_partitions instead is simpler
	// in most cases. However, this property allows building this vbmeta partition without
	// its chained partitions existing in this build.
	Chained_partition_metadata []ChainedPartitionProperties

	// List of chained partitions that this vbmeta delegates the verification. They are the
	// names of other vbmeta modules.
	Chained_partitions []string

	// List of key-value pair of avb properties
	Avb_properties []avbProperty
	}

	type avbProperty struct {
	// Key of given avb property
	Key *string

	// Value of given avb property
	Value *string
	}

	type ChainedPartitionProperties struct {
	// Name of the chained partition
	Name *string

	// Rollback index location of the chained partition. Must be 0, 1, 2, etc. Default is the
	// index of this partition in the list + 1.
	Rollback_index_location *int64

	// Path to the public key that the chained partition is signed with. If this is specified,
	// private_key is ignored.
	Public_key *string `android:"path"`

	// Path to the private key that the chained partition is signed with. If this is specified,
	// and public_key is not specified, a public key is extracted from this private key and
	// the extracted public key is embedded in the vbmeta image.
	Private_key *string `android:"path"`
	}

	type vbmetaPartitionInfo struct {
	// Name of the partition
	Name string

	// Rollback index location, non-negative int
	RollbackIndexLocation int

	// The path to the public key of the private key used to sign this partition. Derived from
	// the private key.
	PublicKey android.Path
	}

	var vbmetaPartitionProvider = blueprint.NewProvider[vbmetaPartitionInfo]()

	// vbmeta is the partition image that has the verification information for other partitions.
	func VbmetaFactory() android.Module {
	module := &vbmeta{}
	module.AddProperties(&module.properties)
	android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibCommon)
	return module
	}

	type vbmetaDep struct {
	blueprint.BaseDependencyTag
	}

	type chainedPartitionDep struct {
	blueprint.BaseDependencyTag
	}

	var vbmetaPartitionDep = vbmetaDep{}
	var vbmetaChainedPartitionDep = chainedPartitionDep{}

	func (v *vbmeta) DepsMutator(ctx android.BottomUpMutatorContext) {
	ctx.AddDependency(ctx.Module(), vbmetaPartitionDep, v.properties.Partitions.GetOrDefault(ctx, nil)...)
	ctx.AddDependency(ctx.Module(), vbmetaChainedPartitionDep, v.properties.Chained_partitions...)
	}

	func (v *vbmeta) installFileName() string {
	return proptools.StringDefault(v.properties.Stem, v.BaseModuleName()+".img")
	}

	func (v *vbmeta) partitionName() string {
	return proptools.StringDefault(v.properties.Partition_name, v.BaseModuleName())
	}

	// See external/avb/libavb/avb_slot_verify.c#VBMETA_MAX_SIZE
	const vbmetaMaxSize = 64 * 1024

	func (v *vbmeta) GenerateAndroidBuildActions(ctx android.ModuleContext) {
	builder := android.NewRuleBuilder(pctx, ctx)
	cmd := builder.Command().BuiltTool("avbtool").Text("make_vbmeta_image")

	key := android.PathForModuleSrc(ctx, proptools.String(v.properties.Private_key))
	cmd.FlagWithInput("--key ", key)

	algorithm := proptools.StringDefault(v.properties.Algorithm, "SHA256_RSA4096")
	cmd.FlagWithArg("--algorithm ", algorithm)

	cmd.FlagWithArg("--rollback_index ", v.rollbackIndexCommand(ctx))
	ril := proptools.IntDefault(v.properties.Rollback_index_location, 0)
	if ril < 0 {
	ctx.PropertyErrorf("rollback_index_location", "must be 0, 1, 2, ...")
	return
	}
	cmd.FlagWithArg("--rollback_index_location ", strconv.Itoa(ril))

	for _, avb_prop := range v.properties.Avb_properties {
	key := proptools.String(avb_prop.Key)
	if key == "" {
	ctx.PropertyErrorf("avb_properties", "key must be specified")
	continue
	}
	value := proptools.String(avb_prop.Value)
	if value == "" {
	ctx.PropertyErrorf("avb_properties", "value must be specified")
	continue
	}
	cmd.FlagWithArg("--prop ", key+":"+value)
	}

	for _, p := range ctx.GetDirectDepsWithTag(vbmetaPartitionDep) {
	f, ok := p.(Filesystem)
	if !ok {
	ctx.PropertyErrorf("partitions", "%q(type: %s) is not supported",
	p.Name(), ctx.OtherModuleType(p))
	continue
	}
	signedImage := f.SignedOutputPath()
	if signedImage == nil {
	ctx.PropertyErrorf("partitions", "%q(type: %s) is not signed. Use `use_avb: true`",
	p.Name(), ctx.OtherModuleType(p))
	continue
	}
	cmd.FlagWithInput("--include_descriptors_from_image ", signedImage)
	}

	seenRils := make(map[int]bool)
	for _, cp := range ctx.GetDirectDepsWithTag(vbmetaChainedPartitionDep) {
	info, ok := android.OtherModuleProvider(ctx, cp, vbmetaPartitionProvider)
	if !ok {
	ctx.PropertyErrorf("chained_partitions", "Expected all modules in chained_partitions to provide vbmetaPartitionProvider, but %s did not", cp.Name())
	continue
	}
	if info.Name == "" {
	ctx.PropertyErrorf("chained_partitions", "name must be specified")
	continue
	}

	ril := info.RollbackIndexLocation
	if ril < 0 {
	ctx.PropertyErrorf("chained_partitions", "rollback index location must be 0, 1, 2, ...")
	continue
	} else if seenRils[ril] {
	ctx.PropertyErrorf("chained_partitions", "Multiple chained partitions with the same rollback index location %d", ril)
	continue
	}
	seenRils[ril] = true

	publicKey := info.PublicKey
	cmd.FlagWithArg("--chain_partition ", fmt.Sprintf("%s:%d:%s", info.Name, ril, publicKey.String()))
	cmd.Implicit(publicKey)
	}
	for _, cpm := range v.properties.Chained_partition_metadata {
	name := proptools.String(cpm.Name)
	if name == "" {
	ctx.PropertyErrorf("chained_partitions", "name must be specified")
	continue
	}

	ril := proptools.IntDefault(cpm.Rollback_index_location, -1)
	if ril < 0 {
	ctx.PropertyErrorf("chained_partition_metadata", "rollback index location must be 0, 1, 2, ...")
	continue
	} else if seenRils[ril] {
	ctx.PropertyErrorf("chained_partition_metadata", "Multiple chained partitions with the same rollback index location %d", ril)
	continue
	}
	seenRils[ril] = true

	var publicKey android.Path
	if cpm.Public_key != nil {
	publicKey = android.PathForModuleSrc(ctx, *cpm.Public_key)
	} else if cpm.Private_key != nil {
	privateKey := android.PathForModuleSrc(ctx, *cpm.Private_key)
	extractedPublicKey := android.PathForModuleOut(ctx, "chained_metadata", name+".avbpubkey")
	ctx.Build(pctx, android.BuildParams{
	Rule: extractPublicKeyRule,
	Input: privateKey,
	Output: extractedPublicKey,
	})
	publicKey = extractedPublicKey
	} else {
	ctx.PropertyErrorf("public_key", "Either public_key or private_key must be specified")
	continue
	}

	cmd.FlagWithArg("--chain_partition ", fmt.Sprintf("%s:%d:%s", name, ril, publicKey.String()))
	cmd.Implicit(publicKey)
	}

	output := android.PathForModuleOut(ctx, v.installFileName())
	cmd.FlagWithOutput("--output ", output)

	// libavb expects to be able to read the maximum vbmeta size, so we must provide a partition
	// which matches this or the read will fail.
	builder.Command().Text("truncate").
	FlagWithArg("-s ", strconv.Itoa(vbmetaMaxSize)).
	Output(output)

	builder.Build("vbmeta", fmt.Sprintf("vbmeta %s", ctx.ModuleName()))

	v.installDir = android.PathForModuleInstall(ctx, "etc")
	ctx.InstallFile(v.installDir, v.installFileName(), output)

	extractedPublicKey := android.PathForModuleOut(ctx, v.partitionName()+".avbpubkey")
	ctx.Build(pctx, android.BuildParams{
	Rule: extractPublicKeyRule,
	Input: key,
	Output: extractedPublicKey,
	})

	android.SetProvider(ctx, vbmetaPartitionProvider, vbmetaPartitionInfo{
	Name: v.partitionName(),
	RollbackIndexLocation: ril,
	PublicKey: extractedPublicKey,
	})

	ctx.SetOutputFiles([]android.Path{output}, "")
	v.output = output
	}

	// Returns the embedded shell command that prints the rollback index
	func (v *vbmeta) rollbackIndexCommand(ctx android.ModuleContext) string {
	if v.properties.Rollback_index != nil {
	return fmt.Sprintf("%d", *v.properties.Rollback_index)
	} else {
	// Take the first line and remove the newline char
	return "$(date -d 'TZ=\"GMT\" " + ctx.Config().PlatformSecurityPatch() + "' +%s \| head -1 \| tr -d '\n'" + ")"
	}
	}

	var _ android.AndroidMkProviderInfoProducer = (*vbmeta)(nil)

	func (v vbmeta) PrepareAndroidMKProviderInfo(config android.Config) android.AndroidMkProviderInfo {
	providerData := android.AndroidMkProviderInfo{
	PrimaryInfo: android.AndroidMkInfo{
	Class: "ETC",
	OutputFile: android.OptionalPathForPath(v.output),
	EntryMap: make(map[string][]string),
	},
	}
	providerData.PrimaryInfo.SetString("LOCAL_MODULE_PATH", v.installDir.String())
	providerData.PrimaryInfo.SetString("LOCAL_INSTALLED_MODULE_STEM", v.installFileName())
	return &providerData
	}

	var _ Filesystem = (*vbmeta)(nil)

	func (v *vbmeta) OutputPath() android.Path {
	return v.output
	}

	func (v *vbmeta) SignedOutputPath() android.Path {
	return v.OutputPath() // vbmeta is always signed
	}