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Commit 1fa1c6db authored by Cole Faust's avatar Cole Faust
Browse files

Build vbmeta partitions with soong 

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.

Bug: 377563298
Test: m nothing (the diff test currently fails, but this is a start)
Change-Id: I397af3a418bd23bcbf8f620c436afcacf69974fd
parent 084877aa

android/variable.go

+14 −1
Original line number Diff line number Diff line
@@ -577,6 +577,14 @@ type PartitionQualifiedVariablesType struct { 
	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
@@ -602,6 +610,11 @@ type PartitionVariables struct { 
	CopyImagesForTargetFilesZip    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"`

filesystem/android_device.go

+5 −1
Original line number Diff line number Diff line
@@ -34,6 +34,8 @@ type PartitionNameProperties struct { 
	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 @@ func AndroidDeviceFactory() android.Module { 
	module := &androidDevice{}

	module.AddProperties(&module.partitionProps)

	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)



	return module

}
@@ -69,6 +70,9 @@ func (a *androidDevice) DepsMutator(ctx android.BottomUpMutatorContext) { 
	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) {

filesystem/vbmeta.go

+12 −16
Original line number Diff line number Diff line
@@ -25,19 +25,19 @@ import ( 
)



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 @@ type vbmetaProperties struct { 
	// 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 @@ type vbmetaProperties struct { 
	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 @@ type avbProperty struct { 
	Value *string

}



type chainedPartitionProperties struct {

type ChainedPartitionProperties struct {

	// Name of the chained partition

	Name *string
@@ -95,7 +94,7 @@ type chainedPartitionProperties struct { 
}



// 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 @@ func (v *vbmeta) GenerateAndroidBuildActions(ctx android.ModuleContext) { 


// 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 "$(" + cmd + " | head -1 | tr -d '\n'" + ")"

		return "$(date -d 'TZ=\"GMT\" " + ctx.Config().PlatformSecurityPatch() + "' +%s | head -1 | tr -d '\n'" + ")"

	}

}



// Extract public keys from chained_partitions.private_key. The keys are indexed with the partition

fsgen/Android.bp

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ bootstrap_go_package { 
        "filesystem_creator.go",

        "fsgen_mutators.go",

        "prebuilt_etc_modules_gen.go",

        "vbmeta_partitions.go",

    ],

    testSrcs: [

        "filesystem_creator_test.go",

fsgen/filesystem_creator.go

+60 −10
Original line number Diff line number Diff line
@@ -44,6 +44,9 @@ func registerBuildComponents(ctx android.RegistrationContext) { 
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 filesystemCreatorFactory() android.Module { 
}



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 @@ func generatedModuleNameForPartition(cfg android.Config, partitionType string) s 
	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 @@ func (f *filesystemCreator) createDeviceModule(ctx android.LoadHookContext) { 


	// 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 @@ func (f *filesystemCreator) createLinkerConfigSourceFilegroups(ctx android.LoadH 
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 @@ func createFailingCommand(ctx android.ModuleContext, message string) android.Pat 
	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 @@ func (f *filesystemCreator) GenerateAndroidBuildActions(ctx android.ModuleContex 
		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...)

}