diff --git a/Dockerfile b/Dockerfile
index d2f971d..2cbfb3d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # ------------------------------------------------------------------------
-from mcluseau/golang-builder:1.13.5 as build
+from mcluseau/golang-builder:1.14.0 as build
 
 # ------------------------------------------------------------------------
 from debian:stretch
diff --git a/cmd/dkl-local-server/boot-iso.go b/cmd/dkl-local-server/boot-iso.go
index 1298440..b9c568d 100644
--- a/cmd/dkl-local-server/boot-iso.go
+++ b/cmd/dkl-local-server/boot-iso.go
@@ -57,7 +57,7 @@ insmod all_video
 set timeout=3
 
 menuentry "Direktil" {
-    linux  /vmlinuz direktil.boot=DEVNAME=sr0 direktil.boot.fs=iso9660
+    linux  /vmlinuz direktil.boot=DEVNAME=sr0 direktil.boot.fs=iso9660 `+ctx.CmdLine+`
     initrd /initrd
 }
 `), 0644)
diff --git a/cmd/dkl-local-server/render-context.go b/cmd/dkl-local-server/render-context.go
index 4a9c76e..7a756cb 100644
--- a/cmd/dkl-local-server/render-context.go
+++ b/cmd/dkl-local-server/render-context.go
@@ -7,6 +7,7 @@ import (
 	"io"
 	"log"
 	"net/http"
+	"net/url"
 	"path/filepath"
 	"text/template"
 
@@ -20,17 +21,25 @@ import (
 type renderContext struct {
 	Host      *localconfig.Host
 	SSLConfig string
+
+	// Linux kernel extra cmdline
+	CmdLine string `yaml:"-"`
 }
 
 func renderCtx(w http.ResponseWriter, r *http.Request, ctx *renderContext, what string,
 	create func(out io.Writer, ctx *renderContext) error) error {
-	log.Printf("sending %s for %q", what, ctx.Host.Name)
 
 	tag, err := ctx.Tag()
 	if err != nil {
 		return err
 	}
 
+	ctx.CmdLine = r.URL.Query().Get("cmdline")
+
+	if ctx.CmdLine != "" {
+		what = what + "?cmdline=" + url.QueryEscape(ctx.CmdLine)
+	}
+
 	// get it or create it
 	content, meta, err := casStore.GetOrCreate(tag, what, func(out io.Writer) error {
 		log.Printf("building %s for %q", what, ctx.Host.Name)
@@ -42,6 +51,7 @@ func renderCtx(w http.ResponseWriter, r *http.Request, ctx *renderContext, what
 	}
 
 	// serve it
+	log.Printf("sending %s for %q", what, ctx.Host.Name)
 	http.ServeContent(w, r, what, meta.ModTime(), content)
 	return nil
 }
diff --git a/cmd/dkl-local-server/ws-host.go b/cmd/dkl-local-server/ws-host.go
index 200de1c..edee5ef 100644
--- a/cmd/dkl-local-server/ws-host.go
+++ b/cmd/dkl-local-server/ws-host.go
@@ -12,7 +12,11 @@ import (
 	"novit.nc/direktil/pkg/localconfig"
 )
 
-var trustXFF = flag.Bool("trust-xff", true, "Trust the X-Forwarded-For header")
+var (
+	trustXFF = flag.Bool("trust-xff", true, "Trust the X-Forwarded-For header")
+
+	cmdlineParam = restful.QueryParameter("cmdline", "Linux kernel cmdline addition")
+)
 
 type wsHost struct {
 	prefix  string
@@ -59,6 +63,7 @@ func (ws *wsHost) register(rws *restful.WebService, alterRB func(*restful.RouteB
 		// read-only ISO support
 		b("boot.iso").
 			Produces(mime.ISO).
+			Param(cmdlineParam).
 			Doc("Get the " + ws.hostDoc + "'s boot CD-ROM image"),
 
 		// netboot support