diff --git a/kernel.go b/kernel.go
index 112944b..58d9b5d 100644
--- a/kernel.go
+++ b/kernel.go
@@ -8,7 +8,9 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"time"
 
+	"github.com/remeh/sizedwaitgroup"
 	"github.com/rs/zerolog/log"
 
 	"code.dumpstack.io/tools/out-of-tree/config"
@@ -35,6 +37,82 @@ type KernelCmd struct {
 	ConfigRegen KernelConfigRegenCmd `cmd:"" help:"regenerate config"`
 }
 
+func (cmd KernelCmd) Generate(g *Globals, km config.Target, max int,
+	shutdown *bool) (err error) {
+
+	// TODO cmd.Update
+
+	container.Commands = g.Config.Docker.Commands
+	container.Registry = g.Config.Docker.Registry
+
+	log.Info().Msgf("Generating for kernel mask %v", km)
+
+	_, err = kernel.GenRootfsImage(container.Image{Name: km.DockerName()},
+		!cmd.NoDownload)
+	if err != nil || *shutdown {
+		return
+	}
+
+	pkgs, err := kernel.MatchPackages(km)
+	if err != nil || *shutdown {
+		return
+	}
+
+	if cmd.Shuffle {
+		pkgs = kernel.ShuffleStrings(pkgs)
+	}
+
+	swg := sizedwaitgroup.New(cmd.Threads)
+
+	for i, pkg := range pkgs {
+		if *shutdown {
+			err = nil
+			return
+		}
+
+		swg.Add()
+
+		if max <= 0 {
+			log.Print("Max is reached")
+			swg.Done()
+			break
+		}
+
+		log.Info().Msgf("%d/%d %s", i+1, len(pkgs), pkg)
+
+		// FIXME
+		go func(p string) {
+			defer swg.Done()
+			var attempt int
+			for {
+				attempt++
+
+				if *shutdown {
+					err = nil
+					return
+				}
+
+				err = kernel.InstallKernel(km, p, cmd.Force, !cmd.NoHeaders)
+				if err == nil {
+					max--
+					break
+				} else if attempt >= cmd.Retries {
+					log.Error().Err(err).Msg("install kernel")
+					log.Debug().Msg("skip")
+					break
+				} else {
+					log.Warn().Err(err).Msg("install kernel")
+					time.Sleep(time.Second)
+					log.Info().Msg("retry")
+				}
+			}
+		}(pkg)
+	}
+	swg.Wait()
+
+	return
+}
+
 type KernelListCmd struct{}
 
 func (cmd *KernelListCmd) Run(g *Globals) (err error) {
@@ -107,18 +185,7 @@ func (cmd KernelAutogenCmd) Run(kernelCmd *KernelCmd, g *Globals) (err error) {
 			return
 		}
 
-		err = kernel.GenerateKernels(sk,
-			g.Config.Docker.Registry,
-			g.Config.Docker.Commands,
-			cmd.Max, kernelCmd.Retries,
-			kernelCmd.Threads,
-			!kernelCmd.NoDownload,
-			kernelCmd.Force,
-			!kernelCmd.NoHeaders,
-			kernelCmd.Shuffle,
-			kernelCmd.Update,
-			&shutdown,
-		)
+		err = kernelCmd.Generate(g, sk, cmd.Max, &shutdown)
 		if err != nil {
 			return
 		}
@@ -148,18 +215,7 @@ func (cmd *KernelGenallCmd) Run(kernelCmd *KernelCmd, g *Globals) (err error) {
 		Distro: distro.Distro{ID: distroType, Release: cmd.Ver},
 		Kernel: config.Kernel{Regex: ".*"},
 	}
-	err = kernel.GenerateKernels(km,
-		g.Config.Docker.Registry,
-		g.Config.Docker.Commands,
-		math.MaxUint32, kernelCmd.Retries,
-		kernelCmd.Threads,
-		!kernelCmd.NoDownload,
-		kernelCmd.Force,
-		!kernelCmd.NoHeaders,
-		kernelCmd.Shuffle,
-		kernelCmd.Update,
-		&shutdown,
-	)
+	err = kernelCmd.Generate(g, km, math.MaxUint32, &shutdown)
 	if err != nil {
 		return
 	}
@@ -186,18 +242,7 @@ func (cmd *KernelInstallCmd) Run(kernelCmd *KernelCmd, g *Globals) (err error) {
 		Distro: distro.Distro{ID: distroType, Release: cmd.Ver},
 		Kernel: config.Kernel{Regex: cmd.Kernel},
 	}
-	err = kernel.GenerateKernels(km,
-		g.Config.Docker.Registry,
-		g.Config.Docker.Commands,
-		math.MaxUint32, kernelCmd.Retries,
-		kernelCmd.Threads,
-		!kernelCmd.NoDownload,
-		kernelCmd.Force,
-		!kernelCmd.NoHeaders,
-		kernelCmd.Shuffle,
-		kernelCmd.Update,
-		&shutdown,
-	)
+	err = kernelCmd.Generate(g, km, math.MaxUint32, &shutdown)
 	if err != nil {
 		return
 	}
diff --git a/kernel/kernel.go b/kernel/kernel.go
index cfd7fe7..6c828fa 100644
--- a/kernel/kernel.go
+++ b/kernel/kernel.go
@@ -14,10 +14,8 @@ import (
 	"regexp"
 	"runtime"
 	"strings"
-	"time"
 
 	"github.com/naoina/toml"
-	"github.com/remeh/sizedwaitgroup"
 	"github.com/rs/zerolog/log"
 
 	"code.dumpstack.io/tools/out-of-tree/cache"
@@ -68,7 +66,7 @@ func vsyscallAvailable() (available bool, err error) {
 	return
 }
 
-func installKernel(sk config.Target, pkgname string, force, headers bool) (err error) {
+func InstallKernel(sk config.Target, pkgname string, force, headers bool) (err error) {
 	slog := log.With().
 		Str("distro_type", sk.Distro.ID.String()).
 		Str("distro_release", sk.Distro.Release).
@@ -281,7 +279,7 @@ func hasKernel(ki config.KernelInfo, kcfg config.KernelConfig) bool {
 	return false
 }
 
-func shuffleStrings(a []string) []string {
+func ShuffleStrings(a []string) []string {
 	// Fisher–Yates shuffle
 	for i := len(a) - 1; i > 0; i-- {
 		j := rand.Intn(i + 1)
@@ -309,79 +307,3 @@ func SetSigintHandler(variable *bool) {
 	}()
 
 }
-
-// FIXME too many parameters
-func GenerateKernels(km config.Target, registry string,
-	commands []config.DockerCommand, max, retries, threads int,
-	download, force, headers, shuffle, update bool,
-	shutdown *bool) (err error) {
-
-	container.Commands = commands
-	container.Registry = registry
-
-	log.Info().Msgf("Generating for kernel mask %v", km)
-
-	_, err = GenRootfsImage(container.Image{Name: km.DockerName()},
-		download)
-	if err != nil || *shutdown {
-		return
-	}
-
-	pkgs, err := MatchPackages(km)
-	if err != nil || *shutdown {
-		return
-	}
-
-	if shuffle {
-		pkgs = shuffleStrings(pkgs)
-	}
-
-	swg := sizedwaitgroup.New(threads)
-
-	for i, pkg := range pkgs {
-		if *shutdown {
-			err = nil
-			return
-		}
-
-		swg.Add()
-
-		if max <= 0 {
-			log.Print("Max is reached")
-			swg.Done()
-			break
-		}
-
-		log.Info().Msgf("%d/%d %s", i+1, len(pkgs), pkg)
-
-		go func(p string) {
-			defer swg.Done()
-			var attempt int
-			for {
-				attempt++
-
-				if *shutdown {
-					err = nil
-					return
-				}
-
-				err = installKernel(km, p, force, headers)
-				if err == nil {
-					max--
-					break
-				} else if attempt >= retries {
-					log.Error().Err(err).Msg("install kernel")
-					log.Debug().Msg("skip")
-					break
-				} else {
-					log.Warn().Err(err).Msg("install kernel")
-					time.Sleep(time.Second)
-					log.Info().Msg("retry")
-				}
-			}
-		}(pkg)
-	}
-	swg.Wait()
-
-	return
-}