most xxx_defconfig stop linking when console support set to CONSOLE_NONE

[Kevin Du Huanpeng]

Hi,
I find that most xxx_defconfig stop linking when console support set
to CONSOLE_NONE
compile log like:
http://paste.ubuntu.com/8518456/

- - - -
  | Symbol: CONSOLE_NONE [=y]                                               |
  | Type  : boolean                                                         |
  | Prompt: none                                                            |
  |   Location:                                                             |
  |     -> General Settings                                                 |
  |       -> console support (<choice> [=y])                                |
  |   Defined at common/Kconfig:522                                         |
  |   Depends on: <choice>                                                  |

- - - -

most error causes by pr_print undefined.

this macro/function is
defined in:
common/console_common.c
declare in:
include/printk.h

when CONSOLE_NONE is defined,
pr_print is not compiled (rid by #ifndef/#endif) with common/console_common.o
but <printk.h> is included allmost anywhere by including <common.h>
- - - -
#ifndef __COMMON_H_
#define __COMMON_H_     1

#include <stdio.h>
...
#include <asm/common.h>
#include <printk.h>
- - - -
so using pr_print always can past compile because it is declared by
including <common.h>.
but breaks link.

I am confusing with CONSOLE_NONE, what is it mean?
1. the board don't have a console?
        is the board still can have a serial port, but not accepts input?
2. where should the debug messages go?
        the serial port is not a console but
        when CONSOLE_NONE defined, printf just a nothing but return a 0,
        but the pr_print() declared but not defined.
- - - -
FILE: include/stdio.h
static inline int printf(const char *fmt, ...)
{
        return 0;
}
- - - -


- - - -
duhuanpeng
(+86)13719074147