extern unsigned int disable_serial_output;
int _serial_getc(int unit, int line, boolean_t wait, boolean_t raw);
extern unsigned int disable_serial_output;
int _serial_getc(int unit, int line, boolean_t wait, boolean_t raw);
int switch_to_serial_console(void);
int switch_to_video_console(void);
void switch_to_old_console(int old_console);
int switch_to_serial_console(void);
int switch_to_video_console(void);
void switch_to_old_console(int old_console);