from include/common.h

/* common/console.c */
int	console_init_f(void);	/* Before relocation; uses the serial  stuff	*/
int	console_init_r(void);	/* After  relocation; uses the console stuff	*/
int	console_assign (int file, char *devname);	/* Assign the console	*/
int	ctrlc (void);
int	had_ctrlc (void);	/* have we had a Control-C since last clear? */
void	clear_ctrlc (void);	/* clear the Control-C condition */
int	disable_ctrlc (int);	/* 1 to disable, 0 to enable Control-C detect */







from main.c

# ifdef CONFIG_AUTOBOOT_KEYED
		int prev = disable_ctrlc(1);	/* disable Control C checking */
# endif

# ifndef CFG_HUSH_PARSER
		run_command (s, 0);
# else
		parse_string_outer(s, FLAG_PARSE_SEMICOLON |
				    FLAG_EXIT_FROM_LOOP);
# endif

# ifdef CONFIG_AUTOBOOT_KEYED
		disable_ctrlc(prev);	/* restore Control C checking */
# endif
	}