Installing 0.7.1, and then rebooting, and doing a ros upgrade to a faked up latest works \o/

Signed-off-by: Sven Dowideit <SvenDowideit@home.org.au>

cmd/control/install/syslinux.go

@@ -0,0 +1,45 @@
+package install
+
+import (
+	"html/template"
+	"os"
+	"path/filepath"
+
+	"github.com/rancher/os/log"
+)
+
+func syslinuxConfig(menu BootVars) error {
+	log.Debugf("syslinuxConfig")
+
+	filetmpl, err := template.New("syslinuxconfig").Parse(`{{define "syslinuxmenu"}}
+LABEL {{.Name}}
+    LINUX ../vmlinuz-{{.Version}}-rancheros
+    APPEND {{.KernelArgs}} {{.Append}}
+    INITRD ../initrd-{{.Version}}-rancheros
+{{end}}
+TIMEOUT 20   #2 seconds
+DEFAULT RancherOS-current
+
+{{- range .Entries}}
+{{template "syslinuxmenu" .}}
+{{- end}}
+
+`)
+	if err != nil {
+		log.Errorf("syslinuxconfig %s", err)
+		return err
+	}
+
+	cfgFile := filepath.Join(menu.BaseName, menu.BootDir+"syslinux/syslinux.cfg")
+	log.Debugf("syslinuxConfig written to %s", cfgFile)
+	f, err := os.Create(cfgFile)
+	if err != nil {
+		log.Errorf("Create(%s) %s", cfgFile, err)
+		return err
+	}
+	err = filetmpl.Execute(f, menu)
+	if err != nil {
+		return err
+	}
+	return nil
+}