diff --git a/config/config.go b/config/config.go
index 5af72c7..7e7c3d5 100644
--- a/config/config.go
+++ b/config/config.go
@@ -23,16 +23,10 @@ type KernelMask struct {
 
 func (km KernelMask) DockerName() string {
 	distro := strings.ToLower(km.DistroType.String())
-	release := strings.Replace(km.DistroRelease, ".", "", -1)
+	release := strings.Replace(km.DistroRelease, ".", "__", -1)
 	return fmt.Sprintf("out_of_tree_%s_%s", distro, release)
 }
 
-func (km KernelMask) ImageName() string {
-	distro := strings.ToLower(km.DistroType.String())
-	release := strings.Replace(km.DistroRelease, ".", "", -1)
-	return fmt.Sprintf("%s_%s.img", distro, release)
-}
-
 type ArtifactType int
 
 const (
diff --git a/kernel.go b/kernel.go
index 9cffdac..bd10428 100644
--- a/kernel.go
+++ b/kernel.go
@@ -97,7 +97,7 @@ func generateBaseDockerImage(sk config.KernelMask) (err error) {
 		d += "ENV DEBIAN_FRONTEND=noninteractive\n"
 		d += "RUN apt-get update\n"
 		d += "RUN apt-get install -y build-essential libelf-dev\n"
-		d += "RUN apt-get install -y wget git libelf-dev\n"
+		d += "RUN apt-get install -y wget git\n"
 	default:
 		s := fmt.Sprintf("%s not yet supported", sk.DistroType.String())
 		err = errors.New(s)
@@ -246,21 +246,110 @@ func genInitrdPath(files []os.FileInfo, kname string) string {
 	return "unknown"
 }
 
-func genRootfsImage(km config.KernelMask) string {
+func genRootfsImage(d dockerImageInfo) string {
 	usr, err := user.Current()
 	if err != nil {
 		return fmt.Sprintln(err)
 	}
-	return usr.HomeDir + "/.out-of-tree/images/" + km.ImageName()
+	imageFile := d.ContainerName + ".img"
+	return usr.HomeDir + "/.out-of-tree/images/" + imageFile
 }
 
-func genKernels(km config.KernelMask, newkcfg *config.KernelConfig) (
+type dockerImageInfo struct {
+	ContainerName string
+	DistroType    config.DistroType
+	DistroRelease string // 18.04/7.4.1708/9.1
+}
+
+func listDockerImages() (diis []dockerImageInfo, err error) {
+	cmd := exec.Command("docker", "images")
+	rawOutput, err := cmd.CombinedOutput()
+	if err != nil {
+		return
+	}
+
+	r, err := regexp.Compile("out_of_tree_.*")
+	if err != nil {
+		return
+	}
+
+	containers := r.FindAll(rawOutput, -1)
+	for _, c := range containers {
+		container := strings.Fields(string(c))[0]
+
+		s := strings.Replace(container, "__", ".", -1)
+		values := strings.Split(s, "_")
+		distro, ver := values[3], values[4]
+
+		dii := dockerImageInfo{
+			ContainerName: container,
+			DistroRelease: ver,
+		}
+
+		dii.DistroType, err = config.NewDistroType(distro)
+		if err != nil {
+			return
+		}
+
+		diis = append(diis, dii)
+	}
+	return
+}
+
+func updateKernelsCfg() (err error) {
+	dockerImages, err := listDockerImages()
+	if err != nil {
+		return
+	}
+
+	newkcfg := config.KernelConfig{}
+
+	for _, d := range dockerImages {
+		err = genKernels(d, &newkcfg)
+		if err != nil {
+			log.Println("gen kernels", d.ContainerName, ":", err)
+			continue
+		}
+	}
+
+	stripkcfg := config.KernelConfig{}
+	for _, nk := range newkcfg.Kernels {
+		if !hasKernel(nk, stripkcfg) {
+			stripkcfg.Kernels = append(stripkcfg.Kernels, nk)
+		}
+	}
+
+	buf, err := toml.Marshal(&stripkcfg)
+	if err != nil {
+		return
+	}
+
+	buf = append([]byte("# Autogenerated\n# DO NOT EDIT\n\n"), buf...)
+
+	usr, err := user.Current()
+	if err != nil {
+		return
+	}
+
+	// TODO move all cfg path values to one provider
+	kernelsCfgPath := usr.HomeDir + "/.out-of-tree/kernels.toml"
+	err = ioutil.WriteFile(kernelsCfgPath, buf, 0644)
+	if err != nil {
+		return
+	}
+
+	log.Println(kernelsCfgPath, "is successfully updated")
+	return
+}
+
+func genKernels(dii dockerImageInfo, newkcfg *config.KernelConfig) (
 	err error) {
 
-	name := km.DockerName()
+	name := dii.ContainerName
 	cmd := exec.Command("docker", "run", name, "ls", "/lib/modules")
 	rawOutput, err := cmd.CombinedOutput()
 	if err != nil {
+		log.Println(string(rawOutput), err)
 		return
 	}
 
@@ -276,14 +365,14 @@ func genKernels(km config.KernelMask, newkcfg *config.KernelConfig) (
 
 	for _, k := range strings.Fields(string(rawOutput)) {
 		ki := config.KernelInfo{
-			DistroType:    km.DistroType,
-			DistroRelease: km.DistroRelease,
+			DistroType:    dii.DistroType,
+			DistroRelease: dii.DistroRelease,
 			KernelRelease: k,
 			ContainerName: name,
 
 			KernelPath: kernelsBase + genKernelPath(files, k),
 			InitrdPath: kernelsBase + genInitrdPath(files, k),
-			RootFS:     genRootfsImage(km),
+			RootFS:     genRootfsImage(dii),
 		}
 		newkcfg.Kernels = append(newkcfg.Kernels, ki)
 	}
@@ -298,7 +387,6 @@ func hasKernel(ki config.KernelInfo, kcfg config.KernelConfig) bool {
 		}
 	}
 	return false
-
 }
 
 func kernelAutogenHandler(kcfg config.KernelConfig, workPath string) (err error) {
@@ -307,8 +395,6 @@ func kernelAutogenHandler(kcfg config.KernelConfig, workPath string) (err error)
 		return
 	}
 
-	newkcfg := config.KernelConfig{}
-
 	for _, sk := range ka.SupportedKernels {
 		if sk.DistroRelease == "" {
 			err = errors.New("Please set distro_release")
@@ -342,27 +428,8 @@ func kernelAutogenHandler(kcfg config.KernelConfig, workPath string) (err error)
 			log.Println("copy kernels", sk.DockerName(), ":", err)
 			continue
 		}
-
-		err = genKernels(sk, &newkcfg)
-		if err != nil {
-			log.Println("gen kernels", sk.DockerName(), ":", err)
-			continue
-		}
 	}
 
-	stripkcfg := config.KernelConfig{}
-	for _, nk := range newkcfg.Kernels {
-		if !hasKernel(nk, stripkcfg) {
-			stripkcfg.Kernels = append(stripkcfg.Kernels, nk)
-		}
-	}
-
-	buf, err := toml.Marshal(&stripkcfg)
-	if err != nil {
-		return
-	}
-	fmt.Println()
-	fmt.Println(string(buf)) // TODO auto-save to some path
-
+	err = updateKernelsCfg()
 	return
 }