1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  linux/arch/arm/kernel/early_printk.c
4 *
5 *  Copyright (C) 2009 Sascha Hauer <s.hauer@pengutronix.de>
6 */
7
8#include <linux/kernel.h>
9#include <linux/console.h>
10#include <linux/init.h>
11#include <linux/string.h>
12
13extern void printascii(const char *);
14
15static void early_write(const char *s, unsigned n)
16{
17	char buf[128];
18	while (n) {
19		unsigned l = min(n, sizeof(buf)-1);
20		memcpy(buf, s, l);
21		buf[l] = 0;
22		s += l;
23		n -= l;
24		printascii(buf);
25	}
26}
27
28static void early_console_write(struct console *con, const char *s, unsigned n)
29{
30	early_write(s, n);
31}
32
33static struct console early_console_dev = {
34	.name =		"earlycon",
35	.write =	early_console_write,
36	.flags =	CON_PRINTBUFFER | CON_BOOT,
37	.index =	-1,
38};
39
40static int __init setup_early_printk(char *buf)
41{
42	early_console = &early_console_dev;
43	register_console(&early_console_dev);
44	return 0;
45}
46
47early_param("earlyprintk", setup_early_printk);
48