arch/mips/kernel/early_printk.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2002, 2003, 06, 07 Ralf Baechle (ralf@linux-mips.org)
   7  * Copyright (C) 2007 MIPS Technologies, Inc.
   8  *   written by Ralf Baechle (ralf@linux-mips.org)
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/console.h>
  12 #include <linux/printk.h>
  13 #include <linux/init.h>
  14
  15 #include <asm/setup.h>
  16
  17 extern void prom_putchar(char);
  18
  19 static void early_console_write(struct console *con, const char *s, unsigned n)
  20 {
  21         while (n-- && *s) {
  22                 if (*s == '\n')
  23                         prom_putchar('\r');
  24                 prom_putchar(*s);
  25                 s++;
  26         }
  27 }
  28
  29 static struct console early_console_prom = {
  30         .name   = "early",
  31         .write  = early_console_write,
  32         .flags  = CON_PRINTBUFFER | CON_BOOT,
  33         .index  = -1
  34 };
  35
  36 void __init setup_early_printk(void)
  37 {
  38         if (early_console)
  39                 return;
  40         early_console = &early_console_prom;
  41
  42         register_console(&early_console_prom);
  43 }