-debug Get shells during process of booting, using GNU screen, most verbose
-grml debug Get shells during process of booting, using GNU screen, verbose
+debug Get shells during process of booting, using GNU screen, be very verbose
+grml debug Get shells during process of booting, using GNU screen, be verbose
+grml debug=1 Get shells during process of booting, using GNU screen, be verbose and
+ display shell code being executed in initramfs.