diff --git a/container/container.go b/container/container.go
index 0afe83f..6878849 100644
--- a/container/container.go
+++ b/container/container.go
@@ -8,7 +8,6 @@ import (
 	"bufio"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path"
@@ -22,7 +21,6 @@ import (
 
 	"code.dumpstack.io/tools/out-of-tree/config"
 	"code.dumpstack.io/tools/out-of-tree/distro"
-	"code.dumpstack.io/tools/out-of-tree/fs"
 )
 
 var Runtime = "docker"
@@ -377,6 +375,48 @@ func (c Container) Run(workdir string, cmds []string) (out string, err error) {
 	return
 }
 
+func FindKernel(entries []os.DirEntry, kname string) (name string, err error) {
+	for _, e := range entries {
+		var fi os.FileInfo
+		fi, err = e.Info()
+		if err != nil {
+			return
+		}
+
+		if strings.HasPrefix(fi.Name(), "vmlinuz") {
+			if strings.Contains(fi.Name(), kname) {
+				name = fi.Name()
+				return
+			}
+		}
+	}
+
+	err = errors.New("cannot find kernel")
+	return
+}
+
+func FindInitrd(entries []os.DirEntry, kname string) (name string, err error) {
+	for _, e := range entries {
+		var fi os.FileInfo
+		fi, err = e.Info()
+		if err != nil {
+			return
+		}
+
+		if strings.HasPrefix(fi.Name(), "initrd") ||
+			strings.HasPrefix(fi.Name(), "initramfs") {
+
+			if strings.Contains(fi.Name(), kname) {
+				name = fi.Name()
+				return
+			}
+		}
+	}
+
+	err = errors.New("cannot find kernel")
+	return
+}
+
 func (c Container) Kernels() (kernels []distro.KernelInfo, err error) {
 	if !c.Exist() {
 		return
@@ -392,27 +432,33 @@ func (c Container) Kernels() (kernels []distro.KernelInfo, err error) {
 		}
 	}
 
-	moddirs, err := ioutil.ReadDir(libmodules)
+	moddirs, err := os.ReadDir(libmodules)
 	if err != nil {
 		return
 	}
 
-	bootfiles, err := ioutil.ReadDir(boot)
+	bootfiles, err := os.ReadDir(boot)
 	if err != nil {
 		return
 	}
 
-	for _, krel := range moddirs {
+	for _, e := range moddirs {
+		var krel os.FileInfo
+		krel, err = e.Info()
+		if err != nil {
+			return
+		}
+
 		c.Log.Debug().Msgf("generate config entry for %s", krel.Name())
 
 		var kernelFile, initrdFile string
-		kernelFile, err = fs.FindKernel(bootfiles, krel.Name())
+		kernelFile, err = FindKernel(bootfiles, krel.Name())
 		if err != nil {
 			c.Log.Warn().Msgf("cannot find kernel %s", krel.Name())
 			continue
 		}
 
-		initrdFile, err = fs.FindInitrd(bootfiles, krel.Name())
+		initrdFile, err = FindInitrd(bootfiles, krel.Name())
 		if err != nil {
 			c.Log.Warn().Msgf("cannot find initrd %s", krel.Name())
 			continue
diff --git a/fs/fs.go b/fs/fs.go
index 75e3393..6b27e99 100644
--- a/fs/fs.go
+++ b/fs/fs.go
@@ -70,33 +70,3 @@ func FindBySubstring(dir, substring string) (k string, err error) {
 	err = errors.New("not found")
 	return
 }
-
-func FindKernel(files []os.FileInfo, kname string) (name string, err error) {
-	for _, file := range files {
-		if strings.HasPrefix(file.Name(), "vmlinuz") {
-			if strings.Contains(file.Name(), kname) {
-				name = file.Name()
-				return
-			}
-		}
-	}
-
-	err = errors.New("cannot find kernel")
-	return
-}
-
-func FindInitrd(files []os.FileInfo, kname string) (name string, err error) {
-	for _, file := range files {
-		if strings.HasPrefix(file.Name(), "initrd") ||
-			strings.HasPrefix(file.Name(), "initramfs") {
-
-			if strings.Contains(file.Name(), kname) {
-				name = file.Name()
-				return
-			}
-		}
-	}
-
-	err = errors.New("cannot find kernel")
-	return
-}
diff --git a/kernel/kernel_linux.go b/kernel/kernel_linux.go
index 063dc4a..f165189 100644
--- a/kernel/kernel_linux.go
+++ b/kernel/kernel_linux.go
@@ -8,13 +8,14 @@
 package kernel
 
 import (
-	"io/ioutil"
+	"os"
 	"os/exec"
 	"strings"
 
 	"github.com/rs/zerolog/log"
 	"github.com/zcalusic/sysinfo"
 
+	"code.dumpstack.io/tools/out-of-tree/container"
 	"code.dumpstack.io/tools/out-of-tree/distro"
 	"code.dumpstack.io/tools/out-of-tree/fs"
 )
@@ -38,12 +39,11 @@ func GenHostKernels(download bool) (kernels []distro.KernelInfo, err error) {
 	}
 
 	kernelsBase := "/boot/"
-	bootfiles, err := ioutil.ReadDir(kernelsBase)
+	bootfiles, err := os.ReadDir(kernelsBase)
 	if err != nil {
 		return
 	}
 
-	// only for compatibility, docker is not really used
 	dist := distro.Distro{
 		ID:      distroType,
 		Release: si.OS.Version,
@@ -58,13 +58,13 @@ func GenHostKernels(download bool) (kernels []distro.KernelInfo, err error) {
 		log.Debug().Msgf("generate config entry for %s", krel)
 
 		var kernelFile, initrdFile string
-		kernelFile, err = fs.FindKernel(bootfiles, krel)
+		kernelFile, err = container.FindKernel(bootfiles, krel)
 		if err != nil {
 			log.Warn().Msgf("cannot find kernel %s", krel)
 			continue
 		}
 
-		initrdFile, err = fs.FindInitrd(bootfiles, krel)
+		initrdFile, err = container.FindInitrd(bootfiles, krel)
 		if err != nil {
 			log.Warn().Msgf("cannot find initrd %s", krel)
 			continue