1 files changed, 70 insertions, 0 deletions
diff --git a/filesystem/system_image.go b/filesystem/system_image.go
new file mode 100644
index 000000000..1d24d6d41
--- /dev/null
+++ b/filesystem/system_image.go
@@ -0,0 +1,70 @@
+// 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 (
+	"android/soong/android"
+	"android/soong/linkerconfig"
+)
+
+type systemImage struct {
+	filesystem
+
+	properties systemImageProperties
+}
+
+type systemImageProperties struct {
+	// Path to the input linker config json file.
+	Linker_config_src *string
+}
+
+// android_system_image is a specialization of android_filesystem for the 'system' partition.
+// Currently, the only difference is the inclusion of linker.config.pb file which specifies
+// the provided and the required libraries to and from APEXes.
+func systemImageFactory() android.Module {
+	module := &systemImage{}
+	module.AddProperties(&module.properties)
+	module.filesystem.buildExtraFiles = module.buildExtraFiles
+	initFilesystemModule(&module.filesystem)
+	return module
+}
+
+func (s *systemImage) buildExtraFiles(ctx android.ModuleContext, root android.OutputPath) android.OutputPaths {
+	lc := s.buildLinkerConfigFile(ctx, root)
+	// Add more files if needed
+	return []android.OutputPath{lc}
+}
+
+func (s *systemImage) buildLinkerConfigFile(ctx android.ModuleContext, root android.OutputPath) android.OutputPath {
+	input := android.PathForModuleSrc(ctx, android.String(s.properties.Linker_config_src))
+	output := root.Join(ctx, "system", "etc", "linker.config.pb")
+
+	// we need "Module"s for packaging items
+	var otherModules []android.Module
+	deps := s.GatherPackagingSpecs(ctx)
+	ctx.WalkDeps(func(child, parent android.Module) bool {
+		for _, ps := range child.PackagingSpecs() {
+			if _, ok := deps[ps.RelPathInPackage()]; ok {
+				otherModules = append(otherModules, child)
+			}
+		}
+		return true
+	})
+
+	builder := android.NewRuleBuilder(pctx, ctx)
+	linkerconfig.BuildLinkerConfig(ctx, builder, input, otherModules, output)
+	builder.Build("conv_linker_config", "Generate linker config protobuf "+output.String())
+	return output
+}