extern int open_chan(struct list_head *chans);
extern int write_chan(struct list_head *chans, const char *buf, int len,
int write_irq);
extern int console_write_chan(struct list_head *chans, const char *buf,
int len);
extern int console_open_chan(struct line *line, struct console *co,
extern int open_chan(struct list_head *chans);
extern int write_chan(struct list_head *chans, const char *buf, int len,
int write_irq);
extern int console_write_chan(struct list_head *chans, const char *buf,
int len);
extern int console_open_chan(struct line *line, struct console *co,