add prebuilt_kernel_modules module
prebuilt_kernel_modules is a build rule for processing and installing
kernel module files. The module files are processed by depmod to build
modules.{load|alias|deps|softdeps} files. Debug symbols are stripped
from the module files and then all the files are installed to
./lib/modules/<kernel_version> directory.
This is the Soong-equivalent of the 'build-image-kernel-modules-dir`
macro and is expected to replace it in the future.
Bug: 178980227
Test: m
Change-Id: I772ac816824921d275869e35b93a083d239a2450
diff --git a/kernel/prebuilt_kernel_modules.go b/kernel/prebuilt_kernel_modules.go
new file mode 100644
index 0000000..94e04cb
--- /dev/null
+++ b/kernel/prebuilt_kernel_modules.go
@@ -0,0 +1,166 @@
+// 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 kernel
+
+import (
+ "fmt"
+ "path/filepath"
+ "strings"
+
+ "android/soong/android"
+ _ "android/soong/cc/config"
+
+ "github.com/google/blueprint"
+ "github.com/google/blueprint/proptools"
+)
+
+func init() {
+ android.RegisterModuleType("prebuilt_kernel_modules", prebuiltKernelModulesFactory)
+ pctx.Import("android/soong/cc/config")
+}
+
+type prebuiltKernelModules struct {
+ android.ModuleBase
+
+ properties prebuiltKernelModulesProperties
+
+ installDir android.InstallPath
+}
+
+type prebuiltKernelModulesProperties struct {
+ // List or filegroup of prebuilt kernel module files. Should have .ko suffix.
+ Srcs []string `android:"path,arch_variant"`
+
+ // Kernel version that these modules are for. Kernel modules are installed to
+ // /lib/modules/<kernel_version> directory in the corresponding partition. Default is "".
+ Kernel_version *string
+}
+
+// prebuilt_kernel_modules installs a set of prebuilt kernel module files to the correct directory.
+// In addition, this module builds modules.load, modules.dep, modules.softdep and modules.alias
+// using depmod and installs them as well.
+func prebuiltKernelModulesFactory() android.Module {
+ module := &prebuiltKernelModules{}
+ module.AddProperties(&module.properties)
+ android.InitAndroidArchModule(module, android.DeviceSupported, android.MultilibFirst)
+ return module
+}
+
+func (pkm *prebuiltKernelModules) KernelVersion() string {
+ return proptools.StringDefault(pkm.properties.Kernel_version, "")
+}
+
+func (pkm *prebuiltKernelModules) DepsMutator(ctx android.BottomUpMutatorContext) {
+ // do nothing
+}
+
+func (pkm *prebuiltKernelModules) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+ modules := android.PathsForModuleSrc(ctx, pkm.properties.Srcs)
+
+ depmodOut := runDepmod(ctx, modules)
+ strippedModules := stripDebugSymbols(ctx, modules)
+
+ installDir := android.PathForModuleInstall(ctx, "lib", "module")
+ if pkm.KernelVersion() != "" {
+ installDir = installDir.Join(ctx, pkm.KernelVersion())
+ }
+
+ for _, m := range strippedModules {
+ ctx.InstallFile(installDir, filepath.Base(m.String()), m)
+ }
+ ctx.InstallFile(installDir, "modules.load", depmodOut.modulesLoad)
+ ctx.InstallFile(installDir, "modules.dep", depmodOut.modulesDep)
+ ctx.InstallFile(installDir, "modules.softdep", depmodOut.modulesSoftdep)
+ ctx.InstallFile(installDir, "modules.alias", depmodOut.modulesAlias)
+}
+
+var (
+ pctx = android.NewPackageContext("android/soong/kernel")
+
+ stripRule = pctx.AndroidStaticRule("strip",
+ blueprint.RuleParams{
+ Command: "$stripCmd -o $out --strip-debug $in",
+ CommandDeps: []string{"$stripCmd"},
+ }, "stripCmd")
+)
+
+func stripDebugSymbols(ctx android.ModuleContext, modules android.Paths) android.OutputPaths {
+ dir := android.PathForModuleOut(ctx, "stripped").OutputPath
+ var outputs android.OutputPaths
+
+ for _, m := range modules {
+ stripped := dir.Join(ctx, filepath.Base(m.String()))
+ ctx.Build(pctx, android.BuildParams{
+ Rule: stripRule,
+ Input: m,
+ Output: stripped,
+ Args: map[string]string{
+ "stripCmd": "${config.ClangBin}/llvm-strip",
+ },
+ })
+ outputs = append(outputs, stripped)
+ }
+
+ return outputs
+}
+
+type depmodOutputs struct {
+ modulesLoad android.OutputPath
+ modulesDep android.OutputPath
+ modulesSoftdep android.OutputPath
+ modulesAlias android.OutputPath
+}
+
+func runDepmod(ctx android.ModuleContext, modules android.Paths) depmodOutputs {
+ baseDir := android.PathForModuleOut(ctx, "depmod").OutputPath
+ fakeVer := "0.0" // depmod demands this anyway
+ modulesDir := baseDir.Join(ctx, "lib", "modules", fakeVer)
+
+ builder := android.NewRuleBuilder(pctx, ctx)
+
+ // Copy the module files to a temporary dir
+ builder.Command().Text("rm").Flag("-rf").Text(modulesDir.String())
+ builder.Command().Text("mkdir").Flag("-p").Text(modulesDir.String())
+ for _, m := range modules {
+ builder.Command().Text("cp").Input(m).Text(modulesDir.String())
+ }
+
+ // Enumerate modules to load
+ modulesLoad := modulesDir.Join(ctx, "modules.load")
+ var basenames []string
+ for _, m := range modules {
+ basenames = append(basenames, filepath.Base(m.String()))
+ }
+ builder.Command().
+ Text("echo").Flag("\"" + strings.Join(basenames, " ") + "\"").
+ Text("|").Text("tr").Flag("\" \"").Flag("\"\\n\"").
+ Text(">").Output(modulesLoad)
+
+ // Run depmod to build modules.dep/softdep/alias files
+ modulesDep := modulesDir.Join(ctx, "modules.dep")
+ modulesSoftdep := modulesDir.Join(ctx, "modules.softdep")
+ modulesAlias := modulesDir.Join(ctx, "modules.alias")
+ builder.Command().
+ BuiltTool("depmod").
+ FlagWithArg("-b ", baseDir.String()).
+ Text(fakeVer).
+ ImplicitOutput(modulesDep).
+ ImplicitOutput(modulesSoftdep).
+ ImplicitOutput(modulesAlias)
+
+ builder.Build("depmod", fmt.Sprintf("depmod %s", ctx.ModuleName()))
+
+ return depmodOutputs{modulesLoad, modulesDep, modulesSoftdep, modulesAlias}
+}