diff --git a/fsgen/Android.bp b/fsgen/Android.bp
index 9fa9557..aa8881f 100644
--- a/fsgen/Android.bp
+++ b/fsgen/Android.bp
@@ -19,7 +19,3 @@
     ],
     pluginFor: ["soong_build"],
 }
-
-soong_filesystem_creator {
-    name: "soong_filesystem_creator",
-}
diff --git a/fsgen/filesystem_creator.go b/fsgen/filesystem_creator.go
index 5eeb0a9..ca948f4 100644
--- a/fsgen/filesystem_creator.go
+++ b/fsgen/filesystem_creator.go
@@ -17,16 +17,12 @@
 import (
 	"android/soong/android"
 	"android/soong/filesystem"
-	"crypto/sha256"
 	"fmt"
 	"strconv"
 
-	"github.com/google/blueprint"
 	"github.com/google/blueprint/proptools"
 )
 
-var pctx = android.NewPackageContext("android/soong/fsgen")
-
 func init() {
 	registerBuildComponents(android.InitRegistrationContext)
 }
@@ -35,22 +31,14 @@
 	ctx.RegisterModuleType("soong_filesystem_creator", filesystemCreatorFactory)
 }
 
-type filesystemCreatorProps struct {
-	Generated_partition_types   []string `blueprint:"mutated"`
-	Unsupported_partition_types []string `blueprint:"mutated"`
-}
-
 type filesystemCreator struct {
 	android.ModuleBase
-
-	properties filesystemCreatorProps
 }
 
 func filesystemCreatorFactory() android.Module {
 	module := &filesystemCreator{}
 
 	android.InitAndroidModule(module)
-	module.AddProperties(&module.properties)
 	android.AddLoadHook(module, func(ctx android.LoadHookContext) {
 		module.createInternalModules(ctx)
 	})
@@ -59,57 +47,36 @@
 }
 
 func (f *filesystemCreator) createInternalModules(ctx android.LoadHookContext) {
-	for _, partitionType := range []string{"system"} {
-		if f.createPartition(ctx, partitionType) {
-			f.properties.Generated_partition_types = append(f.properties.Generated_partition_types, partitionType)
-		} else {
-			f.properties.Unsupported_partition_types = append(f.properties.Unsupported_partition_types, partitionType)
-		}
-	}
+	f.createSystemImage(ctx)
 }
 
-func (f *filesystemCreator) generatedModuleNameForPartition(cfg android.Config, partitionType string) string {
-	prefix := "soong"
-	if cfg.HasDeviceProduct() {
-		prefix = cfg.DeviceProduct()
-	}
-	return fmt.Sprintf("%s_generated_%s_image", prefix, partitionType)
-}
-
-// Creates a soong module to build the given partition. Returns false if we can't support building
-// it.
-func (f *filesystemCreator) createPartition(ctx android.LoadHookContext, partitionType string) bool {
+func (f *filesystemCreator) createSystemImage(ctx android.LoadHookContext) {
 	baseProps := &struct {
 		Name *string
 	}{
-		Name: proptools.StringPtr(f.generatedModuleNameForPartition(ctx.Config(), partitionType)),
+		Name: proptools.StringPtr(fmt.Sprintf("%s_generated_system_image", ctx.Config().DeviceProduct())),
 	}
 
 	fsProps := &(filesystem.FilesystemProperties{})
 	partitionVars := ctx.Config().ProductVariables().PartitionVarsForSoongMigrationOnlyDoNotUse
-	specificPartitionVars := partitionVars.PartitionQualifiedVariables[partitionType]
+	systemPartitionVars := partitionVars.PartitionQualifiedVariables["system"]
 
 	// BOARD_AVB_ENABLE
 	fsProps.Use_avb = proptools.BoolPtr(partitionVars.BoardAvbEnable)
 	// BOARD_AVB_KEY_PATH
-	fsProps.Avb_private_key = proptools.StringPtr(specificPartitionVars.BoardAvbKeyPath)
+	fsProps.Avb_private_key = proptools.StringPtr(systemPartitionVars.BoardAvbKeyPath)
 	// BOARD_AVB_ALGORITHM
-	fsProps.Avb_algorithm = proptools.StringPtr(specificPartitionVars.BoardAvbAlgorithm)
+	fsProps.Avb_algorithm = proptools.StringPtr(systemPartitionVars.BoardAvbAlgorithm)
 	// BOARD_AVB_SYSTEM_ROLLBACK_INDEX
-	if rollbackIndex, err := strconv.ParseInt(specificPartitionVars.BoardAvbRollbackIndex, 10, 64); err == nil {
+	if rollbackIndex, err := strconv.ParseInt(systemPartitionVars.BoardAvbRollbackIndex, 10, 64); err == nil {
 		fsProps.Rollback_index = proptools.Int64Ptr(rollbackIndex)
 	}
 
-	fsProps.Partition_name = proptools.StringPtr(partitionType)
+	fsProps.Partition_name = proptools.StringPtr("system")
 	// BOARD_SYSTEMIMAGE_FILE_SYSTEM_TYPE
-	fsProps.Type = proptools.StringPtr(specificPartitionVars.BoardFileSystemType)
-	if *fsProps.Type != "ext4" {
-		// Currently the android_filesystem module type only supports ext4:
-		// https://cs.android.com/android/platform/superproject/main/+/main:build/soong/filesystem/filesystem.go;l=416;drc=98047cfd07944b297a12d173453bc984806760d2
-		return false
-	}
+	fsProps.Type = proptools.StringPtr(systemPartitionVars.BoardFileSystemType)
 
-	fsProps.Base_dir = proptools.StringPtr(partitionType)
+	fsProps.Base_dir = proptools.StringPtr("system")
 
 	fsProps.Gen_aconfig_flags_pb = proptools.BoolPtr(true)
 
@@ -136,75 +103,9 @@
 	// - filesystemProperties.Build_logtags
 	// - filesystemProperties.Fsverity.Libs
 	// - systemImageProperties.Linker_config_src
-	if partitionType == "system" {
-		ctx.CreateModule(filesystem.SystemImageFactory, baseProps, fsProps)
-	} else {
-		ctx.CreateModule(filesystem.FilesystemFactory, baseProps, fsProps)
-	}
-	return true
-}
-
-func (f *filesystemCreator) createDiffTest(ctx android.ModuleContext, partitionType string) android.Path {
-	partitionModuleName := f.generatedModuleNameForPartition(ctx.Config(), partitionType)
-	systemImage := ctx.GetDirectDepWithTag(partitionModuleName, generatedFilesystemDepTag)
-	filesystemInfo, ok := android.OtherModuleProvider(ctx, systemImage, filesystem.FilesystemProvider)
-	if !ok {
-		ctx.ModuleErrorf("Expected module %s to provide FileysystemInfo", partitionModuleName)
-	}
-	makeFileList := android.PathForArbitraryOutput(ctx, fmt.Sprintf("target/product/%s/obj/PACKAGING/%s_intermediates/file_list.txt", ctx.Config().DeviceName(), partitionType))
-	// For now, don't allowlist anything. The test will fail, but that's fine in the current
-	// early stages where we're just figuring out what we need
-	emptyAllowlistFile := android.PathForModuleOut(ctx, "allowlist_%s.txt", partitionModuleName)
-	android.WriteFileRule(ctx, emptyAllowlistFile, "")
-	diffTestResultFile := android.PathForModuleOut(ctx, "diff_test_%s.txt", partitionModuleName)
-
-	builder := android.NewRuleBuilder(pctx, ctx)
-	builder.Command().BuiltTool("file_list_diff").
-		Input(makeFileList).
-		Input(filesystemInfo.FileListFile).
-		Input(emptyAllowlistFile).
-		Text(partitionModuleName)
-	builder.Command().Text("touch").Output(diffTestResultFile)
-	builder.Build(partitionModuleName+" diff test", partitionModuleName+" diff test")
-	return diffTestResultFile
-}
-
-func createFailingCommand(ctx android.ModuleContext, message string) android.Path {
-	hasher := sha256.New()
-	hasher.Write([]byte(message))
-	filename := fmt.Sprintf("failing_command_%x.txt", hasher.Sum(nil))
-	file := android.PathForModuleOut(ctx, filename)
-	builder := android.NewRuleBuilder(pctx, ctx)
-	builder.Command().Textf("echo %s", proptools.NinjaAndShellEscape(message))
-	builder.Command().Text("exit 1 #").Output(file)
-	builder.Build("failing command "+filename, "failing command "+filename)
-	return file
-}
-
-type systemImageDepTagType struct {
-	blueprint.BaseDependencyTag
-}
-
-var generatedFilesystemDepTag systemImageDepTagType
-
-func (f *filesystemCreator) DepsMutator(ctx android.BottomUpMutatorContext) {
-	for _, partitionType := range f.properties.Generated_partition_types {
-		ctx.AddDependency(ctx.Module(), generatedFilesystemDepTag, f.generatedModuleNameForPartition(ctx.Config(), partitionType))
-	}
+	ctx.CreateModule(filesystem.SystemImageFactory, baseProps, fsProps)
 }
 
 func (f *filesystemCreator) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	if ctx.ModuleDir() != "build/soong/fsgen" {
-		ctx.ModuleErrorf("There can only be one soong_filesystem_creator in build/soong/fsgen")
-	}
-	f.HideFromMake()
 
-	var diffTestFiles []android.Path
-	for _, partitionType := range f.properties.Generated_partition_types {
-		diffTestFiles = append(diffTestFiles, f.createDiffTest(ctx, partitionType))
-	}
-	for _, partitionType := range f.properties.Unsupported_partition_types {
-		diffTestFiles = append(diffTestFiles, createFailingCommand(ctx, fmt.Sprintf("Couldn't build %s partition", partitionType)))
-	}
-	ctx.Phony("soong_generated_filesystem_tests", diffTestFiles...)
 }
diff --git a/fsgen/filesystem_creator_test.go b/fsgen/filesystem_creator_test.go
index 554b66b..6bb0e77 100644
--- a/fsgen/filesystem_creator_test.go
+++ b/fsgen/filesystem_creator_test.go
@@ -44,13 +44,12 @@
 		}),
 		android.FixtureMergeMockFs(android.MockFS{
 			"external/avb/test/data/testkey_rsa4096.pem": nil,
-			"build/soong/fsgen/Android.bp": []byte(`
-			soong_filesystem_creator {
-				name: "foo",
-			}
-			`),
 		}),
-	).RunTest(t)
+	).RunTestWithBp(t, `
+	soong_filesystem_creator {
+		name: "foo",
+	}
+	`)
 
 	fooSystem := result.ModuleForTests("test_product_generated_system_image", "android_common").Module().(interface {
 		FsProps() filesystem.FilesystemProperties