1/* 2 * linux/arch/arm/kernel/early_printk.c 3 * 4 * Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11#include <linux/kernel.h> 12#include <linux/console.h> 13#include <linux/init.h> 14 15extern void printch(int); 16 17static void early_write(const char *s, unsigned n) 18{ 19 while (n-- > 0) { 20 if (*s == '\n') 21 printch('\r'); 22 printch(*s); 23 s++; 24 } 25} 26 27static void early_console_write(struct console *con, const char *s, unsigned n) 28{ 29 early_write(s, n); 30} 31 32static struct console early_console_dev = { 33 .name = "earlycon", 34 .write = early_console_write, 35 .flags = CON_PRINTBUFFER | CON_BOOT, 36 .index = -1, 37}; 38 39static int __init setup_early_printk(char *buf) 40{ 41 early_console = &early_console_dev; 42 register_console(&early_console_dev); 43 return 0; 44} 45 46early_param("earlyprintk", setup_early_printk); 47