rem: if (serial_debug_on)
add: if (sSerialDebugEnabled)
context: dbg_puts(const char *s){	cpu_status state = disable_interrupts();	acquire_spinlock(&dbg_spinlock);	if (serial_debug_on)		arch_dbg_con_puts(s);	release_spinlock(&dbg_spinlock);	restore_interrupts(state);}