if serial output is enabled in the boot monitor, on the first serial line,

enable serial debug output in the kernel too.

kernel/start.c

@@ -71,6 +71,9 @@ U16_t parmoff, parmsize;	/* boot parameters offset and length */
 	system_hz = atoi(value);
   if(!value || system_hz < 2 || system_hz > 50000)	/* sanity check */
 	system_hz = DEFAULT_HZ;
+  value = get_value(params_buffer, "cttyline");
+  if(value && atoi(value) == 0)
+	do_serial_debug=1;
 
   /* Return to assembler code to switch to protected mode (if 286), 
    * reload selectors and call main().